Gas-liquid multiphase flow frequently occurs in many industrial fields such as petroleum, chemical, power, metallurgy, and the online identification of its flow pattern and non-separation measurement of its flowrate are of great scientific and engineering significance. Since the thermophysical properties of gas phase and liquid phase are different, the change of the components of gas-liquid multiphase flow will cause the corresponding temperature response of the pipe wall heated by constant heat flow. Based on this phenomenon, our team proposed a thermal-diffusion measurement method to indirectly invert the flow pattern and the phase flowrates of the gas-liquid multiphase by the fluctuation of the temperature of the pipe wall, and the method was completely verified in the laboratory. This new method had the advantages of non-contact, radiation-free, low cost, real-time online, and no applied resistance, which helped the online monitoring and intelligent transformation of gas-liquid multiphase flow in industrial processes.

The phenomenon of gas-liquid two-phase flow widely exists in many fields such as petroleum extraction and transportation, energy and chemical industry, aerospace and so on. Based on the finite element multiphysics coupling simulation technology, a two-dimensional geometric section simulation model of typical gas-liquid two-phase full-steady-state flow was established to recognize the gas-liquid two-phase flow pattern. The design of the ultrasonic transducer transmitting and receiving modes with two transmitters and four receivers and the sampling mode of three-time combined sampling was used to test the gas-liquid two-phase flow patterns, and the feature mapping of the sound pressure signals combined with the ultrasonic propagation mechanism in gas-liquid fluids was used as the input parameter of the extreme gradient boosting (XGBoost) classification algorithm to realize the classification of the gas-liquid two-phase flow patterns into four types: laminar flow, vesicular flow, annular flow, and plug flow. On this basis, the two types of laminar flow and plug flow were subdivided by exploiting the ultrasonic mechanism, i.e., smooth laminar flow, undulating laminar flow and plug flow, segmental plug flow, so as to realize the classification of all flow types of gas-liquid two-phase flow. Comparison of ultrasonic propagation mechanism features and time-frequency domain features showed that the ultrasonic-based multi-reception distributed ultrasonic testing system constructed in this study was able to extract ultrasonic mechanism feature parameters with better flow pattern recognition, and had a higher recognition rate compared with the time-frequency features. The recognition rate of gas-liquid two-phase flow, laminar flow, vesicular flow, annular flow, and plug flow, was 98.5%. Among these, the highest recognition rate of the smooth laminar flow and undulating laminar flow was 96.15%, while that of plug flow and segmental plug flow reached 96.85%.

Gas-liquid two-phase flow has complex and changeable flow states, including typical states and transition states. The accurate identification and monitoring of flow state are crucial for understanding the mechanism of two-phase flow and ensuring the safe operation of industrial processes. However, the limitation of deployment cost of sensors and the difficulty of data acquisition in actual two-phase flow processes lead to the data deficiency in gas-liquid two-phase flow. In this paper, the problem of few-shot flow state identification of gas-liquid two-phase flow was systematically discussed, which was researched under the framework of information processing of conductance sensor, time-frequency analysis in multi-scale domain and few-shot learning by the prototypical network. Firstly, the water holdup information reflecting dynamic characteristics and flow structure of gas-liquid two-phase flow was obtained by the conductance method with fast response, safety and low cost. Then, the response signal of the conductance sensor was analyzed by time-frequency analysis. The fluctuation information of conductance signal in multi-scale domain was obtained by the improved empirical wavelet transform method, which characterized different flow states jointly. Finally, the extracted features were embedded into the prototypical network, and the model was trained under the meta-learning framework to solve the problem of gas-liquid two-phase flow state identification in few-shot scenario. The few-shot state identification experiments were carried out through 6 typical flow states and 4 transition states. When only 3 or 5 samples were available for target flow states during training, the comprehensive recognition accuracy exceeded 80%, which verified the effectiveness of the method.

Gas-solid two-phase flow is prevalent in fields such as petroleum, chemical engineering, nuclear energy, environmental, and biomedical engineering. Precise phase fraction measurement is vital for system safety and efficiency. This paper aimed to develop an online measurement system based on the multi-frequency electrical capacitance method to enhance the accuracy and anti-interference capability of gas-solid phase fraction measurement. The system utilized an FPGA to control a DAC module to generate multi-frequency excitation signals, combined with a C/V conversion circuit and DPSD algorithm to extract real and imaginary parts of the signal. Experiments simulated gas-solid two-phase conditions using acrylic rods of different diameters in an acrylic pipeline, measuring within a frequency range of 500kHz to 1MHz. The results confirmed the system's ability to accurately measure phase fractions, exhibiting strong stability and interference resistance. This research offered an efficient electrical approach for real-time gas-solid flow measurement, with broad potential applications in industrial processes and biomedical monitoring.

Disturbance waves widely exist in evaporators, natural gas and other industrial environments in annular mist flow pattern, among which the disturbance wave velocity is an important parameter for gas-liquid momentum transfer, heat-transfer and friction pressure drop prediction. To improve the predicted accuracy, the physical-guided neural network (PGNN) was proposed based on the three-fluid model, where the gas core mixture parameters and liquid film parameter were revised by considering the effect of droplet entrained in the gas core. For the experiments, flow tests on various carrier gas parameter and liquid flow rate were conducted, the wave velocities were obtained by using dual conductivity ring liquid film sensor, and the droplet entrainment was measured by using the developed liquid film extraction and metering device. The entrainment correlation was developed with the parameters of gas Weber number and liquid Reynolds number. The hyperparameters of the proposed physical-guided neural network was optimized, and the database of 288 set covering various two-phase flow conditions (pipe diameter, operational pressure, physical properties of the medium, flow direction) was used for the prediction. The results indicated that 76.74% data were within ±5.0% error bands and 94.10% data were within ±15.0% error bands. The predicted accuracy and scalability could be largely enhanced for the proposed PGNN method.

Oil-water two-phase flow in horizontal pipelines exhibits complex and diverse dynamics, with intricate fluid structures and uncertain mechanisms of flow regime transitions. To facilitate the visualization of the oil-water two-phase flow process, a multiphase flow ultrasonic testing simulation platform was established to study the complex interfacial effects and relative motion between phases. Utilizing finite volume method (FVM) based three-dimensional fluid simulation software, a dynamic flow model for oil-water mixed inputs was developed. By extracting the coordinates of the multiphase interface cross-section, a two-dimensional geometric partition model of the test field was constructed using finite element method (FEM) within a multiphysics coupled simulation software, establishing a coupled FVM-FEM visualization simulation platform for multiphase flow. The mechanisms of interaction between oil-water two-phase flow and ultrasound were investigated under ultrasonic excitation. The research findings indicated that in the dynamic water-in-oil and oil-in-water flow regimes within the horizontal pipeline, the number of discrete phases increased within a certain range, but decreased due to coalescence, with the ultrasonic attenuation coefficient positively correlating with the number of discrete oil or water droplets. An in-depth exploration of the transition process from water-in-oil to oil-in-water reverse regimes was conducted, where both phases existed in a non-discrete form and the ultrasonic attenuation coefficient increased with the number of layers.

Aiming at the accurate identification of horizontal oil-gas-water three-phase flow pattern, a combined pulse-wave and continuous-wave ultrasonic sensing measurement method and a multi-domain feature extraction scheme were proposed. In this study, horizontal oil-gas-water three-phase flow dynamic experiments were firstly conducted, and a pulse-wave ultrasonic sensor with a single piezoelectric chip and a continuous-wave ultrasonic sensor with two piezoelectric chips were adopted to synchronously acquire the echo intensity data and Doppler frequency shift data during the flow process. By analyzing the signal responses to different flow patterns, the flow characteristics of different oil-gas-water three-phase flow patterns were revealed. Then, the probability distribution of the radial position of the maximum value in the echo intensity profile, the time series of the average flow velocity and the decomposition of the Doppler frequency shift signal were calculated, and several features were extracted from them to quantify the distribution characteristics of phase interfaces in spatial domain and the fluctuation characteristics of the flow velocity in time and frequency domains. Using the extracted multi-domain feature vector, a classifier based on the random forest was finally constructed, and 8 types of horizontal oil-gas-water three-phase flow patterns were accurately identified with a total identification accuracy of 96.6%. The proposed method provides a simple, efficient, low-cost, and non-invasive solution for the flow pattern identification of complex industrial multiphase flows, which has important scientific and engineering significance.

This paper proposed and validated a prediction model for interfacial wave velocity in annular flow within vertical pipes based on ensemble learning. By optimizing the parameters of empirical wavelet transform (EWT) using whale optimization algorithm (WOA), the signal processing accuracy was enhanced. Key features of the interfacial wave velocity signal were extracted from both time and frequency domains based on theoretical models. Further, models such as support vector regression, decision tree regression, random forest regression, least squares boosting (LSBoost) regression, and Bagging regression were combined to develop a high-precision wave velocity prediction model, with gas-liquid interfacial wave velocity as the prediction target under varying flow rates and pressure conditions. The analysis results showed that the proposed model effectively captured the complex flow characteristics in gas-liquid two-phase flow, with the LSBoost regression achieving a root mean square error (RMSE) of 3.96×10^-7, indicating excellent stability and predictive accuracy. The model provided effective support for the analysis of gas-liquid two-phase flow behavior and engineering practice, especially under complex operating conditions, where the model could still predict wave velocity stably. The model hold broad application prospects and potential, with significant value in practical engineering applications.

This study proposed a multi-parameter extraction method for particle-containing droplets based on the DeepViT deep learning model and rainbow scattering, allowing simultaneous and accurate measurement of the host droplet size and volume fraction of inclusions from the extinction rainbow pattern. The basic composition and implementation methods of the DeepViT model were introduced, including training data preprocessing and network hyperparameters setting. Then, the rainbow optical system and typical measurement signals of particle-containing droplets were demonstrated, and the measurement results of this method under different host droplet sizes and inclusion volume fraction were analyzed and compared with the measurement values of the extinction rainbow method. The relative error of the droplet size measured by this method under the inclusion volume fraction of 0—0.3% was within ±0.5%, while the maximum relative error of the extinction rainbow method was about 2%. The maximum absolute error of measuring the inclusion volume fraction under the droplet size of 120—140μm was less than 0.01%. The proposed DeepViT-based method could quickly achieve high-precision in-situ parameter measurements of dynamic heterogeneous droplets such as particle-containing droplets, providing a new idea for the development of particle-containing droplet measurement techniques.

Addressing the issues of insufficient reduction accuracy and susceptibility to noise interference in current 3D morphology measurement methods for droplet evaporation processes, this paper presented an LED off-axis digital holography system utilizing the Linnik interference method. The optical system employed an LED light source combined with reference light attenuation technology to enhance the system's performance and reduce coherent noise. Algorithmically, a dual-exposure method in conjunction with a weighted least squares phase unwrapping algorithm was adopted to correct phase distortions and mitigate coherent noise, thereby improving imaging quality. Utilizing this system, the evaporation process of microscale anhydrous ethanol droplets on a vertical glass surface was investigated, achieving 3D morphology restoration and dynamic contact angle measurement during droplet evaporation. The results indicated that the droplet contact angle exhibited asymmetry in different directions, with significant differences observed particularly at a 45° angle to the direction of gravity. During evaporation, factors such as gravity and uneven surface properties influenced droplet evaporation behavior, resulting in differential evaporation rates across different directions. The research work presented in this paper provided a novel method for dynamic measurement of 3D morphologies of microscale droplets, offering potential significant support for research in the fluid interface science and related fields.

Under gravity-driven flow, the liquid film on an inclined wall can initially spread completely across the surface, but under heating conditions, a drying phenomenon may occur, forming local dry spots, which significantly reduce heat transfer efficiency and potentially damage equipment performance. Investigating the flow instability and the drying mechanism of the liquid film is crucial for optimizing the falling film evaporation process and the design of heat exchangers. In this study, a micrometer was used to measure the liquid film thickness, and the thickness characteristics of the liquid film on an inclined wall were examined under both heating and adiabatic conditions. The formation and evolution of “dry spots” during the flow were precisely captured, along with the effect of critical spraying density on flow instability. A three-dimensional model was proposed to accurately predict the occurrence of dry spots on the inclined wall, which simultaneously considered the thermal capillarity and evaporation effects of the liquid film. The results showed that under adiabatic conditions, the rate of change in the liquid film thickness was divided into rapid and gradual phases, with liquid viscosity and inclination angle playing key roles in the rapid change phase. The critical spraying density increased significantly with the inclination angle, mainly due to the combined effects of gravity and surface tension fluctuations, which enhanced the flow instability of the liquid film. Under heating conditions, both experimental and model analysis revealed the formation process of the drying mechanism, emphasizing how the surface tension gradient induced by thermal capillarity and evaporation effects work together, causing local rupture of the liquid film at the bottom of the wall, eventually leading to the formation of dry spot region. The findings of this study enriched the understanding of liquid film flow characteristics in falling film evaporation processes and provided technical support for the design of falling film heat exchangers.

Droplet impacts, widely observed in nature and industrial processes, often involve interaction between droplet and liquid film, coupled with the complex mass and heat transfer. An experimental setup for droplet impacts on flowing liquid film was designed and constructed enabling the generation of both single and successive droplets with high repeatability. By utilizing high-speed photography and image processing methods, the morphological characteristics of droplet impacts on flowing liquid film and inclined substrate were quantitatively analyzed. It was found that for the same film Reynolds number R{e}_{\mathrm{f}}, the characteristics of the crown formed by droplet spreading varied significantly under different droplet Weber numbers W{e}_{\mathrm{d}}. Notable asymmetry in the crown characteristics was observed upstream and downstream of the liquid film flow. In the case of successive droplet impacts, the spreading process of the crown formed by the second droplet was significantly accelerated, and the duration of the crown was shorter. Significant asymmetry was also observed in the dynamic evolution of successive droplet impacts on an inclined substrate, with a notable reduction in temperature at the impact point after the droplets impacting the heated substrate.

Droplet breakup, as the secondary breakup phenomenon during liquid atomization, plays an important role in many fields, such as fuel combustion in internal combustion engines and spray cooling. Although droplet breakup in continuous flow has been well studied, the mechanism of droplet breakup in shear flow environment is still deficient in the reported related studies. In this paper, we investigated the droplet breakup characteristics in shear flow with medium shear effect by means of a high-speed camera observation system, combining with image processing and analyzing software such as Matlab and ImageJ. The experiments distinguished two different manifestations of bag-stamen breakup as mushroom bag-stamen breakup and cane bag-stamen breakup, whose main characteristics differences were reflected in the different position of the liquid stamen structure. Based on the experimental data, a prediction function of the degree of deformation applicable to the two manifestations of bag-stamen breakup was established, and the average relative error of the function was only 3.85% after verification of the experimental data. In addition, the study quantified the sub-droplet size distribution law of the two manifestations of bag-stamen breakup and analyzed and measured the effects of the hollow bag structure, bag-ring structure and stamen structure on the percentage of sub-droplet size in the bag-stamen breakup.

The measurement of frozen droplet is crucial for understanding droplet icing mechanisms and predicting icing processes. Here, a Fourier transform infrared spectrometer was used to measure the absorption spectra of pure water at room temperature (295.7K) and ice at various temperatures (253.2—270.7K). Based on the Beer-Lambert law, a droplet height inversion model was developed, and the combinations of optimal wavelengths were identified by analyzing the spectral data. A measurement system based on absorption spectroscopy was also developed. The influence of spot position on measurement accuracy was analyzed. On this basis, the freezing processes of droplets with different volumes (5μL, 10μL and 20μL) were measured by the developed system and imaging method simultaneously. Meanwhile, temperature changes were monitored by thermocouples to assess whether the droplets had completely frozen. It was showed that the maximum deviations between the two methods were 3.4% and 19.2% for droplets at room temperature and frozen droplets, respectively, since the measurement accuracy was affected by the droplet tip that formed after freezing.

Co-firing of methane (CH‍₄) and ammonia (NH‍₃) is reliable technological pathway for decarbonization in high-temperature thermal processes. During high-flux binary fuel feeding, poor combustion organization can lead to trace-level fuel leakage, and abnormal operation of the de-nitrification system can exacerbate ammonia slip. Therefore, simultaneous measurement of binary fuel slip is urgently needed. Additionally, the high concentration of water vapor in the flue gas during methane-ammonia combustion introduces significant molecular broadening effects, posing challenges for traditional and widely-used laser absorption-based spectroscopic detection. This study presented a frequency-division multiplexing-wavelength modulation spectroscopy technique for simultaneous trace-level binary fuels under high-humidity environments. By configuring trace-level (1×10^-6—100×10^-6) mixtures in 10%—50% high-humidity atmospheres, the effect of water vapor on the spectral broadening of CH₄ and NH₃ was quantified, and a linear relationship between CH₄ and NH₃ concentrations and the target harmonic signal peaks was established. A systematic comparison between frequency-division multiplexing and single-channel measurements was conducted to verify the reliability of the results. Allan variance analysis showed that detection limits for methane and ammonia were both below 82×10^-9 and 88×10^-9. Real-time measurements of the known concentration gas mixtures further verified the method's sensitivity and rapid response capabilities.

In the harsh measurement environment of the boiler, in order to ensure the continuous effectiveness and reliability of the thermal radiation imaging technology for online detection of the temperature field distribution in the furnace, the fusion of deep learning algorithms was used to obtain the temperature field distribution in the furnace. After data extraction and calculation for a 350MW coal-fired boiler with a quadrangular cut-circle design, a dataset containing operating parameters and temperature field distribution in the furnace was obtained and divided and preprocessed, and then MLP, LSTM, and TCNN models for temperature field prediction were respectively established and trained based on the dataset. The temperature field prediction and error analysis were carried out for different load conditions using the three models, and the evaluation indicators were calculated and compared using the test set. Results illustrated that in the variable load operation range, the TCNN model had the best generalization ability of the furnace temperature field among the three models, and could more accurately predict the distribution of the furnace combustion temperature field. Among the three models, the mean absolute error (MAE) and root mean square error (RMSE) of the TCNN model for the test set were reduced to 45.51K and 59.73K, and the average prediction relative error was less than 3.6%, which met the requirements of engineering applications. It was demonstrated that the model could be used to make up for the deficiency of failure in acquiring the temperature field in the furnace during the cleaning of the image probe, thereby ensuring the continuity and reliability of online detection of the temperature field under the harsh measurement environment in the furnace.

The load signal in coal-fired power plants is calculated based on steam parameters, but the thermal inertia of the furnace process causes a lag in steam parameter changes, affecting the load monitoring and adjustment decisions of the operators. Therefore, this paper proposed an improved load monitoring method based on the time series alignment of flame image features, leveraging the ability of flame images to reflect the actual conditions inside the furnace. This method firstly converted boiler flame monitoring videos into continuous image frames, then extracted flame temporal features through a series of adaptive preprocessing steps, including filtering and segmentation. Dimensionality reduction was then applied to obtain the flame image indicators, and finally, dynamic time warping (DTW) algorithm was used to align the flame image indicators with the load signal, generating an alignment path and time-delay curve between them. Analysis showed that the DTW algorithm significantly enhanced the correlation between flame image indicators and load signals under typical operating conditions (50%, 80%, and 100% load), providing an efficient solution for monitoring load fluctuations in coal-fired power plants.

The convective heat transfer characteristics of supercritical CO₂ were investigated experimentally in different heated mini-channels under horizontal flow condition. The results showed that the convective heat transfer coefficients of supercritical CO₂ increased significantly with the increase of mass flow rate. But the convective heat transfer coefficients decreased obviously with the increase of heating power and inlet temperature. However, the trends of convective heat transfer coefficient under the pressure condition were totally different. When the fluid temperature was below the pseudo-critical temperature, the convective heat transfer coefficient of supercritical CO₂ increased significantly with the loss of pressure. If the fluid temperature was higher than the pseudo-critical temperature, the convective heat transfer coefficient of supercritical CO₂ increased significantly with the increase of pressure. The convection heat transfer coefficient of supercritical CO₂ significantly rose with the reduction of diameter of mini-channel when the different experimental parameters (pressure, mass flow rate, heating power, and inlet temperature) held constant, respectively. Compared with the convective heat transfer coefficient when the diameter of mini-channel was 1mm, the variation of different experimental parameters had no significant influence on the minimum and maximum of relative heat transfer enhancement rates of supercritical CO₂ when the diameters of heated tube were 0.75mm and 0.5mm, respectively. If the buoyancy effect would be ignored in different heated mini-channels. The variation trend of convective heat transfer coefficient could be explained reasonably by the drastic change of thermal physical properties of supercritical CO₂ near the pseudo-critical region.

To realize online morphology information measurement of HMX molding powders, the particle imaging probe and acquisition system were developed. Experimental studies were conducted to capture the images of suspended particles of molding powders. Using Mask RCNN as framework, an image processing method based on improved Swin Transformer was proposed, and the CA-Swin Transformer structure was proposed by connecting channel attention module (CAM) and the window-based multi-head self-attention (W-MSA) in parallel, which was utilized to reasonably allocate the attention degree of image channels. The particle recognition network (PRNet) was further established by combining the proposed feature enhancement module (FEM) with CA-Swin Transformer, effectively improving the recognition accuracy of particle images. The PRNet was trained and tested with the labeled image dataset of HMX molding powders. The obtained results showed that the AP, AP₅₀ and AP₇₅ of PRNet reached 62.3%, 84.4% and 72.5%, respectively. The relative errors of recognized feature particle sizes D₁₀, D₅₀, D₉₀ and D_max relative to manual labeling were -4.788%, -0.770%, -0.272% and 0.313%, respectively, outperforming baseline network Mask RCNN and its variant with the Swin Transformer backbone. Moreover, PRNet exhibited a better recovery ability for the occluding part of overlapping particles. The absolute relative errors of circularity, Feret diameter and aspect ratio of overlapping particles relative to manual labeling were less than 8%, 4% and 5%, respectively.

With the increasing difficulty of tapping the remaining oil potential in domestic onshore old oil fields, traditional layered water injection technology has shown a series of problems such as low measurement and adjustment efficiency, poor accuracy, frequent downhole operations, and high production costs. It can no longer further improve the oil displacement effect and achieve the strategic goal of fine water injection. To address this issue, an evaluation was conducted on the practical application of intelligent water injection wells in low-permeability oil fields, and a new method was proposed to analyze the wellbore and reservoir status using intelligent layered water injection technology. Through on-site experimental research on intelligent injection wells in low-permeability blocks of oil fields, it had been verified that for layered injection wells in sections 3—7, the measurement and adjustment accuracy of layered flow rate was better than 5%, the adjustment time was 30—60min, and the operating cost was about 2000CNY, which was 1/6, 1/30, and 1/10 of traditional processes, respectively. This achieved refined management of reservoir water injection, reduced production costs, and significantly improved water injection efficiency and crude oil recovery rate. Moreover, relying on intelligent water injection wells, real-time monitoring of reservoir parameters could be achieved. For low-permeability reservoirs, effective single-layer indicator curves could be recorded within 10min, and effective reservoir pressure recovery curves could be recorded within 5h. Compared with traditional processes, this improved the efficiency and quality of data recording. Based on this, the injection production plan, reservoir status, and implementation measures could be effectively evaluated to meet the needs of reservoir analysis and provide new ideas for the development of intelligent layered water injection technology.

Establishing chemical process models using deep learning often faces challenges such as high costs of data acquisition and scarcity of data. In response to this, this paper proposed a low-cost data augmentation modeling method called mGAN-NN, which was based on generative adversarial networks (GANs). The method introduced the maximum mean discrepancy (MMD) into the loss function of the generator of GANs, thereby improving the similarity of the distribution features between the generated data and the real data. Then, the generated data were used to establish a neural network model, which was subsequently fine-tuned using real experimental data. The significant advantage of this method was its ability to construct robust models with limited data. The proposed method was applied to establish a prediction model for the active content of fatty acid methyl ester sulfonate (MES) in a microreactor. The model achieved a coefficient of determination (R²) of 0.91, representing a 236% improvement over the traditional neural network (ANN) and a 32% improvement over the support vector regression (SVR). Moreover, the mean absolute error (MAE) was reduced to 3.38, which was 58% lower than that of ANN and 45% lower than that of SVR, demonstrating excellent generalization and prediction accuracy.

Green hydrogen energy is expected to develop alongside renewable energy power systems in the future, which contributes to the achievement of carbon neutrality goals. It can be widely used in fuel, chemical, steel, oil refining and other fields, and has potential application in all power fields. Since 2022, green hydrogen has shown strong demand for green methanol and green ammonia synthesis, and is expected to lead in industrialization in different hydrogen energy applications. However, whether green hydrogen energy is used to synthesize methanol or ammonia is not clearly understood at the technical and industrial levels. In this research, the technology and industry of green hydrogen conversion to green methanol and green ammonia were analyzed. The main contents of this paper included the introduction of green methanol and green ammonia synthesis/decomposition technology, qualitative description and quantitative analysis of the process and economy. This paper tryied to give a clear skeleton and hoped to provide reference for the development of green hydrogen in China.

Gas hydrate technology has broad application prospects in the seawater desalination, hydrate cold storage, carbon dioxide storage, etc. The hydrate formation speed is one of the key issues restricting the application of hydrate technology. The CO₂ hydrate formation with rhamnolipid enhancement were studied using a self-built CO₂ hydrate generation visualization experimental device, and the effects of rhamnolipids on gas consumption, induction time and morphological images during the formation of CO₂ hydrate were analyzed. The results showed that in the rhamnolipid solution, the gas consumption was increased by 4.47mmol/mol, but the induction time was shortened by 260min, comparing with pure water. It is found that the induction time of hydrate formation in 0.2% rhamnolipid solution was the shortest, and then the continuous increase of concentration inhibited the growth of hydrate from the study of the CO₂ hydrate formation characteristics in different concentrations of rhamnolipid solution. In addition, there was a linear relationship between the induction time and the initial temperature change in the system because the CO₂ hydrate gas consumption decreased with the increase of initial temperature which led to decrease in the degree of supercooling. The increase of initial pressure resulted in shortening induction time and reducing the amount of hydrate formation. There were great differences in the morphological images of CO₂ hydrate formation in rhamnolipid solution under different generation conditions.

The photothermal heat source can solve problems such as low elemental utilization in low and medium coal gasification processes, but the reaction characteristics are different from those of conventional coal gasification processes due to changes in the properties of the heat source and the heat transfer method, and the introduction of the mixing agent for CO₂ dissipation will have an impact on the temperature field in the reactor. In order to study the above problems, this paper constructed a lignite fixed-bed gasification reactor with a photothermal heat source using the multi-field coupling software Comsol Multiphysics, and investigated the influence laws of the temperature distribution and product composition as well as the changes of the heat and mass transfer behaviors in the reactor with different thermal conductivity characteristics of the gasification mediums steam, carbon dioxide and different ratios of the mixing gasification agents. As the proportion of CO₂ added to the gasification agent increased from 0 to 100%, the viscosity and density of the fluid continued to increase, resulting in an increase in the viscous force between the fluids and a decrease in the momentum transfer, and the convective heat transfer coefficient between the gas-solid phases decreased from 26.3W/(m²·K) to 22.7W/(m²·K). Compared with steam gasification, the addition of CO₂ reduced the particle gasification temperature and the reaction rate of coal gasification, but the increase of CO₂ concentration was conducive to increase the reaction rate of semi-coke CO₂ reduction. Under the combined effect, the complete gasification time of coal coke particles did not change significantly. In addition, the optical heat saving heat medium heating mode made the reactor bed temperature curve overall "funnel-shaped", which led to the extension of the particle gasification time in the center by 70min, and after the mixing of CO₂, the reduction of thermal conductivity made the temperature curve appeared obvious "lag effect". Finally, by adjusting the proportion of CO₂ added to the gasification medium, it was found that when the proportion of CO₂ added increased to 40%, the gasification medium exhibited the behavior of exogenous CO₂ absorption and its CO₂ absorption reached 0.013g/g. As the gasification temperature increased, the reaction rate of CO₂ gasification increased, which ultimately showed an increase in CO₂ consumption and the effective syngas yield, but a decrease in the H₂/CO ratio.

Dry electrode technology is one of the currently advanced manufacturing technologies for lithium-ion batteries, but there are few reported literatures on this technology. Besides, the content of the binder polytetrafluoroethylene (PTFE) in the recent studies is greater than 5%. Therefore, ternary dry electrode films of 140μm and 180μm were prepared with different contents of PTFE by hot pressing method after homogenization of the materials. The influence and mechanism of PTFE content on the physical and electrochemical properties of ternary materials were studied, such as fibrosis, membrane structure morphology, optical contact angle, tensile strength, resistivity, charge discharge, etc. The results indicated that macroscopically, the content of PTFE did not affect the homogenization of the material fibrillation. Microscopically, the number of fine fibrous binders observed in the cross-section of the film by scanning electron microscopy was significantly higher than that on the surface. The film with 2.5% of PTFE exhibited the smallest optical contact angle of approximately 68°, the lowest resistivity of 10.35Ω·cm, and a relatively high tensile strength of 4.512MPa. The film with 180μm thick had the best rate performance, with a discharge capacity of 149.13mAh/g at 1C. Based on the above research, it is believed that dry electrode technology is a highly feasible industrial electrode preparation technique.

This review examines the current development in selective catalytic reduction (SCR) for denitrification (de-NO _x ), and introduces the unique advantages of ultra-low temperature SCR in terms of energy savings, cost reduction, mitigation of dust and anti SO₂ poisoning. It further summarizes the types of ultra-low temperature SCR catalysts, their structural characteristics, and the main challenges in applications, such as low de-NO _x activity, poor H₂O tolerance, and insufficient stability. Additionally, this review outlines the research progress in H₂O and SO₂ poisoning resistance of ultra-low temperature SCR catalysts. Finally, it proposes future development directions for ultra-low temperature SCR catalysts, emphasizing the need for in-depth research to enhance catalyst activity, improve H₂O and SO₂ tolerance, increase catalyst production, and understand the reaction mechanisms. In conclusion, ultra-low temperature ammonia SCR catalysts offer significant environmental and economic benefits, with broad application prospects in the field of air pollution control.

[Cu(EDTA)]^2- intercalated ZnAl hydrotalcite-like precursors with different Cu proportions were successfully prepared by the co-precipitation method, and then calcined to form mixed metal oxide catalysts. The catalysts were characterized by X-ray powder diffraction (XRD), Fourier transform infrared (FTIR), N₂ physical adsorption and desorption, transmission electron microscopy (TEM), N₂O titration test, inductively coupled plasma-emission spectroscopy (ICP-OES), H₂ programmed temperature-raising reduction (H₂-TPR), and X-ray photoelectron spectroscopy (XPS). Subsequently, the catalytic performance of these CuZnAl catalysts in CO hydrogenation reaction was evaluated. The results indicated that smaller CuO particles were beneficial to increasing the oxygen vacancies, Cu dispersion and Cu specific surface area, enhancing the activation of reactants, and improving catalytic activity. Notably, compared with other catalysts, the HT-Cu_0.5(EDTA) catalyst exhibited stronger domain-limiting effect of the hydrotalcite-like laminates, leading to the smaller CuO particle size, higher Cu dispersion, larger exposed Cu specific surface area, easier reduction to Cu⁰, stronger interaction between Cu species and ZnO on the laminates, and more oxygen vacancies. These features facilitated the adsorption and activation of the reactants, resulting in a remarkable space-time total alcohol yield of 1448.9mg ROH/(g Cu·h), demonstrating superior catalytic performance.

Modification of graphite phase carbon nitride (g-C₃N₄, CN) is an important means to improve its photocatalytic performance. S-doped carbon nitride (SCN) was prepared by thermal polymerization with thiourea as the precursor, and binary heterojunction composite photocatalysts CN-Ti and SCN-Ti were prepared with graphite phase carbon nitride, S-doped carbon nitride and TiO₂ as the main components. The morphology, structure, optical and electrochemical properties of the photocatalyst were analyzed by X-ray diffraction, scanning electron microscope, X-ray photoelectron spectroscopy, specific surface area, ultraviolet-visible diffuse reflectance and electrochemical test, and their photocatalytic performance were evaluated by degradation of NO. According to the free radical capture experiment, the photocatalytic degradation mechanism was further studied. The results showed that the binary heterojunction composite photocatalyst SCN-Ti had better photocatalytic performance. When the mass ratio of SCN∶TiO₂ was 5∶5, the photocatalytic NO degradation rate was the highest, reaching 84.9% and 57.1% under ultraviolet light and visible light, respectively, which was significantly higher than that of CN (61.7% and 44.2%, respectively), and after five cycles, it still had good photocatalytic activity. The improvement of photocatalytic activity was mainly attributed to the type Ⅱ heterojunction constructed by SCN and TiO₂, which promoted carrier separation and improved the generation efficiency of photogenerated electrons, holes and ·{\mathrm{O}}_{\mathrm{2}}^{-} free radicals that degraded NO active substances. This study provided a reference for broadening the application of g-C₃N₄ in the field of photocatalysis.

Janus organic porous membrane is a special membrane material with opposite two-sided properties or asymmetrical structure. Compared with a single organic porous membrane material, which has inherent limitations such as low permeability, poor selectivity and easy contamination, Janus organic porous membrane materials with unique transport behavior and separation characteristics can effectively overcome the above shortcomings, and thus they have attracted great attention. In this paper, the preparation methods of asymmetric wettable Janus organic porous membranes in recent years, including asymmetric polymerization method and single-sided modification method, were systematically summarized, and the applications of asymmetric wettable Janus organic porous membrane materials in membrane separation, membrane distillation, fog collection, unidirectional water conducting fabrics, medical and other fields were summarized in detail. The existing problems and future development were also summarized and prospected.

Interface diffusion behavior between asphalt rejuvenators and aged asphalt is the key factor affecting hot recycling efficiency, process level and service performance of reclaimed asphalt pavement. Simulation methods of diffusion state of rejuvenators into aged asphalt were systematically reviewed including soaking method, layered extraction technology, surface wettability method, tracer method and molecular dynamics simulation method. The advantages and disadvantages of existing research methods were comparatively analyzed, on the basis of which, characterization methods and evaluation parameters of different time history diffusion states were summarized. The characteristics and applicability of various evaluation methods were discussed. The future research direction of characterization methods of diffusion behavior of asphalt rejuvenators was prospected. Research results showed that diffusion samples prepared based on the surface wettability method had unique methods and indicators for characterizing diffusion states, which were suitable for evaluating interface characteristics and instant diffusion rate of rejuvenators wetting aging asphalt. Tracer technologies could capture the slice blending status of diffusion samples. Diffusion characterization methods of soaking method and layered extraction technology were more diversified. The combination of molecular dynamics simulation and diffusion test considering thermodynamic parameters was the main pathway to study diffusion behavior and driving force mechanism of asphalt rejuvenators. In the future, the research on the lateral diffusion behavior of asphalt rejuvenators along the asphalt film surface should be strengthened, and a variety of contact modes between rejuvenators and aged asphalt should be considered. The diffusion kinetic model considering time-temperature attenuation effect needed to be established, which provided a theoretical basis and reference for scientifically determining process parameters of hot recycled asphalt pavement.

With the in-depth promotion of the "double carbon strategy" policy, the low-carbon and low-emission lifestyle has been widely recognized by the public, so the diversified and clean utilization of carbon materials has been widely concerned. As an important branch of activated carbon, spherical activated carbon (SAC) has a good application prospect in gas capture, sewage purification, energy storage, chemical protection, catalysis and other fields due to its high sphericity, well-developed pore structure, uniform particle distribution, low flow resistance and high mechanical strength. However, some precursors have some problems in the preparation of SAC, such as complicated process, high energy consumption and long time, and easy to produce by-products. In order to optimize the design idea and preparation process of SAC, this paper, guided by the application development of SAC in different fields, summarized the selection of precursor, preparation process, modification measures of SAC and the research achievements and progress in various application fields, and prospected the future application of SAC. It provided reference for realizing the multi-functional, large-scale, green and low-carbon development of SAC and promoting the clean and high value-added utilization of its precursor.

Phase change materials (PCMs) refer to materials that change the physical properties of substances with temperature changes and can provide latent heat, which has a wide range of application prospects in the fields of solar thermal storage, electronic equipment, power battery thermal management and building temperature control, etc., and has been listed as a national R&D utilization sequence in China. However, problems such as leakage, low thermal conductivity and weak light absorption hinder the wider application and development of phase change materials. To overcome these inherent problems and improve their thermophysical properties, carbon-based materials used as encapsulation carrier to construct stable shape composite phase change materials can effectively prevent solid-liquid phase change leakage and improve the latent heat properties. In this paper, the main research progress of porous carbon supporting materials (such as carbon nanotubes, graphene, activated carbon, biochar, etc.) as PCMs encapsulation carriers was reviewed. The effects of different porous carbon materials as encapsulation carriers on the physical properties of PCM composites such as thermal conductivity, latent heat, phase transition temperature, subcooling, shape stability and thermal cycle stability were introduced. The research trends and applications of different porous carbon-based composite phase change materials in latent thermal properties were introduced. Finally, the future research and challenges of porous carbon-based materials were summarized and prospected.

Drilling in ultra-deep formation is faced with complex geological environment such as ultra-high temperature, ultra-high pressure and ultra-high stress, as well as salt paste layer and fractured formation, which leads to conformational changes such as fracture and twisting of key materials such as fluid loss reducer in drilling fluid, resulting in complex situations such as increased fluid loss and deterioration of rheological properties during drilling. Therefore, from the perspectives of optimizing linear polymer molecular structure, and regulating polymer condensed state structure and nano-composite technology, this paper reviewed the research progress of polymer fluid loss reducer for ultra-deep drilling fluid and pointed out the shortcomings of the existing three methods. In addition, it was proposed to use nano micron spherical or hyperbranched tree structure, further study the synergistic mechanism between zwitterionic polymer groups, introduce materials with hydrophobic groups to improve the dispersion stability of nanomaterials, and use molecular simulation combined with laboratory experiments to develop polymer filtration reduction agents with high performance and strong universality. Moreover, artificial intelligence and big data technology should be combined to improve the self-regulation and optimization function of drilling fluid.

Aiming at the current lack of systematic and perfect analysis and testing standards for high-temperature resistant fibers at home and abroad, the problem of unrealistic mixing ratio of high-temperature resistant fibers in the filter media market and the uneven quality of products, a summary was made based on the research results and progress of the analysis and testing of existing high-temperature composite filter media fibers. This paper introduced the high temperature filter media industry commonly used organic fibers, inorganic fibers and their physical and chemical characteristics, focusing on an overview of conventional detection methods such as chemical dissolution method, combustion method, modern testing techniques such as infrared method, thermogravimetric method, differential thermal method, polarized light method, and the use of multi-instrument combined use of technology in the composite filter media fibers quantitative and qualitative analysis of the current status of the test. Combined with the pros and cons of the measured method of high-temperature resistant fibers, the future development trend of analysis and testing was proposed. It was believed that since the conventional combustion method was subject to subjective influence and dissolution method polluted the environment, the future analysis and testing of high temperature composite filter media fibers should take into account the modern testing technology to explore a variety of methods and combination of different technologies, and should be accelerated in the future to improve the quantitative analysis and testing standards of high temperature fibers.

Supercritical water oxidation (SCWO) is a highly efficient and environmentally friendly advanced oxidation technology, which is widely used to treat a variety of high-concentration pollutants, but acidic substances are generated during the treatment process, leading to corrosion of the equipment, which seriously limits the development of SCWO. Ni-based alloys with excellent high-temperature strength, oxidation and corrosion resistance are one of the candidate materials for the preparation of SCWO equipment, and it is of great significance for the development of the technology to investigate the corrosion phenomena and mechanisms in SCWO. This paper reviewed the corrosion of Ni-based alloys in supercritical water environment containing different aggressive ions (O^2-、Cl^-、S^2-、PO{}_{\mathrm{4}}^{\mathrm{3}-}, etc.), and summarized the effect of different aggressive ions on corrosion. It was found that the corrosion of the alloy was more affected in the environment containing Cl or S. The corrosion mechanism of Ni-based alloys in supercritical water by different aggressive ions was discussed in detail, and two methods to slow down the corrosion by coating and surface modification were proposed. Finally, the future development direction of alloy corrosion was discussed, and it was proposed to use isotope labeling and pure metal corrosion to deeply analyze and elucidate the corrosion mechanism of alloys in the oxidizing environment of supercritical water.

In this review, the core mechanism, technical progress and wide application in many disciplines of atomic force microscope infrared spectroscopy (AFM-IR) were discussed. AFM-IR technology combined the nanoscale spatial resolution of atomic force microscope (AFM) with the chemical analysis capability of infrared spectroscopy (IR). Based on the principle of photothermal induced resonance (PTIR), AFM-IR technology not only continued the advantages of AFM in the characterization of micro-morphology, but also overcame the limitation of traditional infrared spectroscopy in spatial resolution. And AFM-IR technology complemented the blank of AFM in chemical component analysis. The principle of AFM-IR and three imaging techniques (contact, tapping and peakforce tapping) were described, and its application in polymer composites, biological tissues, environmental contaminant detection, and the characterization of piezoelectric ferroelectric materials and battery materials were discussed. At the same time, the challenges of AFM-IR technology in improving signal to noise ratio (SNR) and its application in soft matter research were also presented. Finally, the direction of future research was proposed in order to promote the further development of AFM-IR technology, and then play a more critical role in the design and performance optimization of materials.

Sodium hypochlorite (NaClO) is widely used as an efficient and inexpensive disinfectant. Electrolysis is a convenient and effective way to produce NaClO with electrodes being the core component of a NaClO generator. These electrodes determine the device's chlorine evolution efficiency, energy consumption and service life. Currently, titanium electrodes coated with mixed metal oxides (Ti/MMO) have become a research focus due to their excellent electrocatalytic activity, long service life and low energy consumption. However, the production cost remains high due to the use of precious metal materials. This paper summarized various electrode materials used for the electrolytic production of NaClO, their composition, performance and development trends. It analyzed the reasons for the passivation of early dimensionally stable anodes (DSA) and focused on three approaches for optimizing electrode preparation processes. Considering current research challenges, the paper anticipated the future development directions of electrode materials, highlighting the rational selection and diversification of metal elements in coatings, the introduction of titanium dioxide nanotube arrays (TNT) intermediate layers viain-situ anodic oxidation, and the combination of hydrothermal synthesis method for electrode preparation as key aspects of process optimization.

Nano-fillers have the advantages of small size and high specific surface area. The introduction of nano-fillers into scale inhibition coatings can further improve the scale inhibition effect of scale inhibition coatings. Therefore, the research and application of composite scale inhibition coatings containing nano-fillers have received extensive attention. In this paper, the scale inhibition mechanism of nano-fillers after adding composite coatings was studied, and the mechanism of nano-fillers in scale inhibition coatings was summarized and analyzed: ① Low surface energy could reduce the nucleation rate, growth rate and adhesion of fouling substances on the coating surface; ② The surface micro-nano structure induced the scale layer to form an unstable crystal structure or inhibited crystal nucleation. In addition, the properties of nano-silica, carbon nanomaterials (carbon nanotubes, carbon nanofibers, graphene and its derivatives, etc.), nano-metal oxides (TiO₂, CeO₂, ZnO) and other commonly used nano-fillers and the advantages and disadvantages after the introduction of coatings were introduced. The preparation process and methods of nano-fillers and scale inhibition coatings were summarized, and the research direction of nano-fillers in scale inhibition coatings was prospected in order to provide some reference for the application of nano-fillers in the field of anti-scaling composite coatings.

Silicon, as one of the most promising anode materials for lithium-ion batteries, boasts a high theoretical capacity (4200mAh/g). However, silicon suffers from poor electrical conductivity and significant volume expansion during the charge-discharge process, leading to pulverization of the anode and a consequent sharp decline in battery performance. Secondary particle formation can enhance the isotropic characteristics of the material, thereby improving the initial Coulombic efficiency and enhancing rate capability. Among the factors, the size of secondary particles is critical. In this study, fulvic acid potassium (FAP) was used as a carbon source to fabricate Si/C anode secondary particles. The Si/C composite anode material was assembled into coin cells and characterized using scanning electron microscopy (SEM) and electrochemical techniques to analyze the impact of the air inlet during the spray drying process on the size of secondary particles. The results indicated that at a spray feed rate of 310mL/h and an air inlet rate of 29m³/h, the Si/C anode composite material achieved an initial Coulombic efficiency of 86.39%. After 100 cycles, the reversible capacity was significantly higher than that of pure silicon anode material, retaining a reversible capacity of 1134.1mAh/g at a 0.1A/g rate test.

Chlorinated titanium dioxide is an important inorganic raw material for chemical industry and energy storage, and its properties are controlled by multiple factors such as sintering heat treatment. Traditional experimental methods are difficult to accurately quantify and analyze the sintering process, and molecular dynamics simulations can accurately assess the dynamic evolution of sintering from the atomic scale, but the existing studies are relatively single-limit for the mechanistic interpretation of factors such as temperature, particle size and arrangement. A non-isotropic multi-particle model and effective characterization parameters such as sintering neck size, Lindemann index and apparent activation energy were introduced, and the effects of temperature, particle size and arrangement on the sintering behavior of TiO₂ nanoparticles were investigated by molecular dynamics simulation system. The results showed that increasing the temperature was conducive to stimulating intense atomic migration and diffusion and accelerating the densification process of the sintered body. When the temperature was the same, the sintering rate of TiO₂ nanoparticles with smaller particle size was faster, but it was easy to be absorbed and fused by the particles with larger particle size. In addition, the particle arrangement also affected the sintering behavior with the stacked arrangement having a more obvious sintering advantage than the linear arrangement. The initial stage of sintering was mainly through surface diffusion growth, while the later stage was through grain boundary diffusion densification. The results were of guiding significance for optimizing industrial sintering parameters and preparing high-performance nanomaterials.

Pure PA 6 membranes and inorganic particle PA 6 composite membranes were prepared through non-solvent induced phase separation (NIPS) method by using formic acid as solvent, poly(caprolactam) (PA 6) as polymer matrix and inorganic nanoparticles as filler. The structures and optical-thermal properties of these membranes were characterized. The results showed that the higher the concentration of the coagulation bath, the more surface pores in the PA 6 membrane and the higher the solar spectral reflectance values. The concentration of the coagulation bath had no significant effect on the pore size and distribution of the cross-section pores of PA 6 membrane. Also, the infrared transmittance in the range of human body thermal radiation (7—14μm) did not change significantly. Compared with pure PA 6 membrane, the addition of inorganic particles could make the surface of the membrane rougher. The visible light spectral reflectance increased and transmittance decreased corresponding to mid- and far-bands. Especially, the number of interface nanopores in the membrane increased after doped with nano SiO₂ particles. Moreover, the thermal stability of the membrane material integrated with 50nm SiO₂ nanoparticles was significantly reduced.

To overcome the "trade-off" between the solvent permeability and solute separation selectivity of traditional thin film polyamide composite (TFC-PA) nano filtration (NF) membrane, the interface polymerization (IP) was regulated by dodecyl sulfate (SDS) and strong base (NaOH) in the aqueous phase. Presence of SDS could reduce interface tension, enrich PIP monomer through electrostatic interaction, protect poly(acyl chloride) monomer from hydrolysis and accelerate the uniform diffusion of PIP molecules across interfaces, leading to improved reaction speed and uniformity in the interface polymerization, while NaOH further accelerated the interface polymerization by absorbing the produced acid to keep the activity of SDS as surfactant and also de-protonating PIP monomer for faster reaction. This synergistic enhancement effect enabled the PA layer of generated composite membrane MPA-SDS-NaOH with aqueous phase containing 0.35%SDS and 0.3%NaOH to have narrowed pore size, increased crosslinking degree from 44.8% to 88.4%, decreased thickness from 125nm to 42nm, leading to increased water permeance from 6.04L/(m²·h·bar) to 19.20L/(m²·h·bar), and increased separation selectivity of NaCl and Na₂SO₄ from 29.4 to 152.6. This cooperative compensatory regulation strategy of SDS and NaOH may provide new avenues for preparing highly permeable and selective TFC-PA NF membranes.

Foam silicon carbide with different pore density and porosity was prepared by organic foam impregnation method, and its phase composition and microstructure were analyzed by XRD, SEM, BET and other testing methods. In order to explore the influence of temperature and pore structure on the electromagnetic characteristics and wave absorption performance of foam silicon carbide, the dielectric parameters of samples with different pore structure from room temperature to 400℃ were measured by using the resonant cavity perturbation technique. The temperature rising behavior of foam silicon carbide with different pore structure was measured by using self-developed microwave tube furnace. The reflection loss of materials was tested using a vector network analyzer. The results showed that the real part of the complex dielectric constant of the prepared samples increased with the increase of temperature, and the highest real part value reached 6.72 at 400℃. As the pore density and porosity increased, the loss tangents of the samples increased with a maximum value of 0.037 at 400℃. The heating rate of the samples increased with the increase of power, pore density and porosity, reaching a maximum of 65.4℃/min at 1400W. The reflection loss of foam silicon carbide decreased regularly with the increase of pore density and porosity, and the minimum value was -12.8dB. The results showed that temperature and pore structure had a great influence on the electromagnetic properties and wave absorption properties of the samples. The higher the pore density and porosity, the stronger the wave absorption properties of foam silicon carbide. This work systematically studied the effects of pore structure and temperature on the microwave absorbing properties of foam silicon carbide, providing theoretical guidance for the research of microwave electromagnetic properties in the field of porous materials.

In order to solve the problem of insufficient structural compactness, the composite ionic solution of zinc lactate and calcium chloride was used to perform binary ionic cross-linking reaction on sodium alginate-based capsules to prepare HPMC-based enteric hard capsules with good compactness and excellent mechanical properties. Structural characterization and performance testing of the capsule membranes were conducted using FTIR, XRD, SEM, EDS, and mechanical property tests. The influence of the Zn²⁺-Ca²⁺ molar ratio in the composite ionic solution on the microstructure and physicochemical properties of the HPMC-based enteric hard capsules was investigated. The study demonstrated that adding a certain amount of zinc lactate enhanced the structural density of the capsules. However, when the Zn²⁺-Ca²⁺ molar ratio exceeded 1∶4, an increase in the proportion of Zn²⁺ led to a decrease in the total content of zinc and calcium in the capsule membranes, along with an increase in the remaining sodium content. This resulted in a reduced cross-linking rate and cross-linking degree between sodium alginate and the ions, ultimately lowering the tensile strength and affecting the capsule’s forming characteristics. Through structural characterization and physicochemical performance evaluation, it was determined that the optimal ratio for the capsule cross-linking reaction was n(Zn²⁺)∶n(Ca²⁺)=1∶4. At this ratio, the capsules exhibited superior mechanical properties and density, with a tensile strength of 50.12MPa, a fracture elongation of 2.0%, a water vapor permeability of 2.75×10⁻¹¹g/(m·s·Pa), a capsule formation rate of 94%, a pass rate of 96% for tightness, and a pass rate of 96% for brittleness. Finally, the HPMC enteric hollow capsule products obtained at the optimal cross-linking ratio demonstrated good appearance quality, with all indicators meeting the standards outlined in the “Pharmacopoeia of the People’s Republic of China”(2020 edition) and relevant industry standards.

Visible light catalytic oxidation is an efficient, energy-saving and environmentally friendly refractory organic wastewater treatment technology. The key to the efficiency of wastewater purification is the performance of the catalyst. Bismuth oxyhalide (BiOX, X=Br, Cl, I), as a bismuth-based semiconductor material, has the characteristics of suitable band gap, high stability and low toxicity. This is because the [Bi₂O₂]²⁺ plate and the double halogen atom layer are interlaced to form a four-fold perovskite structure. This special layered structure and broadened energy band structure greatly reduce the recombination of photogenerated electron-hole pairs, but the disadvantages of low quantum efficiency, wide band gap, and difficulty in recycling limit its scale application. Iron-based materials have excellent optical properties and play a role of activating oxidant, and are usually magnetic. The combination of the bismuth oxyhalide and iron-based materials can solve the problem of difficult recovery of bismuth oxyhalide and improve the photocatalytic performance. Therefore, this paper reviewed the types, synthesis methods, catalytic performance and reusability of magnetic materials from bismuth oxyhalide to different iron-based composite bismuth oxyhalide magnetic materials, in order to provide reference for improving the recovery efficiency, reusability and photocatalytic performance of photocatalytic materials. It was expected that the removal efficiency of refractory organic pollutants could reach 80%—100% in the practical engineering application of iron-based composite bismuth oxyhalide magnetic catalyst. In the future, the key to the application of iron-based composite bismuth oxyhalide magnetic materials in printing and dyeing wastewater, pharmaceutical wastewater and organic chemical wastewater was to reduce the cost of materials, innovate modification methods, and put them into practical engineering on a large scale, so as to improve their cost performance and practicability.

Phosphorus resources are abundant in our country, but the majority of them are middle-low-grade phosphorus ore. The efficient development and comprehensive utilization of these resources are crucial requirements for the sustainable development of phosphate resources in our country. This article systematically reviewed and summarized the current research status of acid production and purification technologies of wet-process phosphoric from middle-low-grade phosphorus ore. Then, it elaborated on the latest research progress in various aspects including pre-treatment techniques of middle-low-grade phosphorus ore, wet-process phosphoric acid preparation technologies and purification technologies. The advantages, disadvantages and existing technical challenges of these technologies were analyzed. Finally, the challenges in preparing wet-process phosphoric acid and its purification from middle-low-grade phosphorus ore were summarized. In the future, research efforts should be intensified in ore pretreatment technologies, impurity removal technologies at the source of phosphor-gypsum and novel purification techniques. These efforts aimed to enhance the purity and quality of phosphoric acid products and achieve the sustainable utilization of phosphate ore resources.

As China's industry and agriculture rapidly develop, a significant amount of environmental endocrine disruptors (EEDs) are transported into the soil matrix by natural or human-induced means. EEDs pollution has led to a decline in soil quality, posing a series of ecological safety and human health concerns and hindering the further development of agriculture in China. Persulfate (PS) advanced oxidation technology offers advantages such as low cost, short cycle, and high efficiency. In the field of EEDs contaminated soil remediation, researcher has selected and focused on three highly representative and widely-studied PS activation techniques: thermal activation, transition metal ion activation, and carbon material activation. This paper introduced the classification, application, sources, and hazards of typical soil EEDs, discussed the basic principles, the advantages and disadvantages of typical activation technologies, highlighted the influencing factors in the degradation process, elaborated on the impact of soil properties on degradation, and concluded with a perspective on future research directions, including the establishment of soil EEDs emission inventories, process customization based on local conditions, prevention and control of secondary pollution, and soil quality assurance, etc., aiming to provide theoretical support for on-site engineering applications in remediating EEDs contaminated soil.

Agriculture is the foundation of China's national economy. In recent years, the rapid development of agriculture has inevitably led to the generation of large amounts of agricultural waste. Given that agricultural waste poses both environmental pollution risks and opportunities for biomass resource utilization, using appropriate conversion technologies to treat this waste can significantly enhance its economic and environmental benefits. Based on the classification, composition and potential value of agricultural waste, this paper introduces the hydrothermal liquefaction technology in thermochemical conversion, and conducts an in-depth discussion on the factors affecting the yield and quality of the main product (biocrude oil) and its separation technologies. It is found that while the synergistic effects of various influencing factors are significant, the interaction mechanisms remain unclear; high-tech separation technologies are continuously emerging, but there are still limitations, and large-scale industrial application has not yet been achieved. Therefore, future efforts should focus on improving the theoretical system of reaction mechanism, optimizing the entire industrial chain layout, developing new catalysts, and integrating various conversion technologies. So that we can fully tap into the potential of hydrothermal technology for the resource utilization of agricultural waste, with a view to ultimately realizing its efficient and comprehensive utilization.

In recent years, the increasingly severe energy crisis and environmental pollution have become great challenges to all mankind, so it is urgent to accelerate energy transition and explore low-carbon, clean, renewable energy sources. As an important category of biomass resources, agricultural waste is abundant and has the dual attributes of environmental pollution risk and resource utilization value, while using appropriate conversion technologies to treat this waste can significantly enhance its economic and environmental benefits. Among numerous conversion technologies, hydrothermal carbonization has been the focus of attention in recent years. Based on the current management and disposal status of agricultural waste, this paper introduces the reaction mechanism of hydrothermal carbonization and the subsequent treatment and utilization value of its products, and conducts an in-depth discussion on the specific applications of hydrochar. It is found that all potential fields are continuously expanding in both depth and breadth, but there are still limitations, and large-scale industrialization has not yet been achieved. Therefore, future efforts should focus on exploring the value-added pathways for gas and liquid phase products, improving the theoretical system of reaction mechanism, optimizing and upgrading the modification processes. So that we can fully explore the key role of hydrothermal technology for the resource utilization of agricultural waste, with a view to provide insights for the development and design of related process technologies and ultimately realize the efficient and comprehensive utilization of agricultural waste.

For resource utilization of desulfurization gypsum and CO₂ sequestration, the process of producing vaterite CaCO₃ by mineralization reaction of desulfurization gypsum under normal temperature and pressure was studied. The influence of crystal control agent on the purity of calcium carbonate and vaterite content of mineralized solid product was investigated and the stability of vaterite was analyzed. The heavy metal content of ammonium sulfate crystals by-products of mineralization was determined and the mechanism of influence of serine on promoting the formation of vaterite CaCO₃ was preliminarily discussed. The results indicated that the purity of calcium carbonate obtained from the mineralization reaction of desulfurization gypsum showed an increasing and then decreasing trend with the increase of the mass ratio of serine to desulfurization gypsum, but the mass ratio of serine to desulfurization gypsum basically did not affect the content of vaterite in the calcium carbonate. Under the condition of stirring rate of 1000r/min, ammonia equivalent ratio of 1.2, CO₂ flow rate of 400mL/min and solid-liquid ratio of 15%, the optimum quality ratio of serine to desulfurization gypsum was 30%. The crystalline transformation of vaterite samples started at 367℃, and the content of calcite in the samples was 74.36% when the calcination temperature was 450℃. Research indicated that the polar side chain hydroxyl group of serine interacted with calcium ions, facilitating the nucleation of vaterite calcium carbonate. Additionally, serine selectively adsorbed onto vaterite, stabilizing its nuclei and inhibiting its transformation into calcite. The addition of serine during the mineralization of CO₂ by desulfurization gypsum was a simple and efficient process method for the preparation of vaterite CaCO₃, which could simultaneously achieve the sequestration and resource utilization of CO₂.

The decrease of environmental pH will affect the biochemical performance of sulfate reduction system, thus enhancing the tolerance of the system under acid stress condition has received extensive attention. In this study, an efficient sulfate-reducing bacteria (SRBs) community was constructed. Using the pure culture system inoculated with Desulfovibrio as the control group, batch experiments were carried out to investigate the effects of pH condition on the microbial growth and sulfate reduction performance of the systems, and to elucidate the physiological responses of the system microorganisms to acid stress. The results showed that the growth of bacteria and sulfate reduction reaction in the pure culture system were significantly inhibited by the decrease of pH. When the pH dropped to 5.0, the bacterial survival rate of the system was less than 10%, and the system lost its sulfate reduction function essentially. In contrast, the microorganisms in the SRBs system could improve the system resistance to acid stress through increasing the activity of ATP hydrolysis enzyme (H⁺-ATPase), producing stress proteins, adjusting the composition and distribution of fatty acids in the cell membrane, etc. After a 7d growth adaptation period, the SRBs system achieved sulfate reduction attaining a SO{}_{\mathrm{4}}^{\mathrm{2}-} removal rate of 30.90% and showed certain advantages in acid resistance. Furthermore, high-throughput sequencing technology was employed to analyze the response of the microbial community in the SRBs system to pH changes. It was found that acid stress had no significant effects on the α diversity of the microbial community in the SRBs system (p>0.05), but it altered the composition of the microbial community structure. The relative abundances of Bacillus and Clostridium increased significantly (26.26% and 5.14%, respectively), becoming the dominant bacterial genera. The research results revealed the adaptive regulatory mechanism of the SRBs system in weak acid environments, thereby providing a theoretical reference for the stable operation of biochemical systems under low pH conditions.

In order to preferably deal with the problem of azo dye pollution in the aquatic environment and make full use of China's abundant natural mineral resources, chrysotile mineral fibers were directly used as heterogeneous catalyst carriers in the experiment. While ensuring the economic application of mineral resources, it should make full use of various active components in chrysotile to explore a new path for the utilization of chrysotile mineral resources. NiCo₂O₄@chrysotile fiber (NC@CF) with core-shell structure was prepared by hydrothermal-calcination method, which was used to activate peroxydisulfate (PDS) to degrade methyl orange (MO). The mechanism of MO degradation in NC@CF/PDS system was investigated by scanning electron microscopy, Fourier transform infrared spectroscopy and other material characterization methods. The results showed that the combination of NiCo₂O₄ and chrysotile had a synergistic effect in the degradation process of MO. The removal rate of MO by NC@CF-2/PDS system with a load ratio of 2∶1 could reach 94.50% under the optimal conditions, and the degradation process conformed to the pseudo-first-order kinetic model. In addition, combined with free radical quenching experiments, electron paramagnetic resonance, X-ray photoelectron spectroscopy and electrochemical experiments, it was shown that the degradation of MO in the NC@CF-2/PDS system was completed by the synergistic effect of the free radical pathway of ·OH and SO₄^-· and the non-free radical pathway of electron transfer.

Excessive discharge of phosphate will cause eutrophication of water body and pose a great threat to water environment safety. As a non-renewable resource, phosphate has significant recycling value. In order to obtain an adsorbent with low cost and excellent performance to effectively recover phosphate from wastewater, alginate-like exopolymers (ALE) was extracted from the residual sludge by high-temperature sodium carbonate method, and FeCa-ALE hydrogel composite was constructed. The microstructure and functional group characteristics of FeCa-ALE were analyzed by scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy (FTIR). Static adsorption experiments showed that FeCa-ALE had good adsorption performance for phosphate, and the actual maximum adsorption capacity was 15.92mg/g at pH of 9. Pseudo-second-order kinetics, Elovich kinetic and Freundlich isotherm model could well describe the adsorption process of FeCa-ALE with respect to phosphate, indicating that the adsorption process was mainly dominated by heterogeneous chemical adsorption. The test of adsorption performance under the real water environment showed that FeCa-ALE with the characteristic of environmentally friendly and biodegradable, could resist the salinity inhibition effect to some extent and remove phosphate from real wastewater.

Resin desulfurization adsorbent was prepared by grafting organic amines on chloromethyl polystyrene macroporous resin (D201) for removing trace CS₂ in benzene. Effects of preparation method including amine type, washing method and mass ratio of resin to amine on the adsorption performance were studied. Besides, relations between performance and absorption conditions such as temperature, space velocity and CS₂ concentration of raw material were also investigated. Adsorption mechanism of the absorbent was revealed by the results from BET, organic element analyzer and Fourier transform infrared spectroscopy (FTIR). It was shown that thioic acid was initially generated by CS₂ and primary-amine and secondary-amine functional groups on the absorbent. Then, it converted to cyanide isosulfate and finally to thiourea as thioic acid was unstable. As a result, trace CS₂ in benzene was removed. The D201-EDA adsorbent prepared by grafting ethylenediamine on D201 exhibited excellent penetration adsorption capacity and saturated adsorption capacity of 183.33mg/g and 200.78mg/g, respectively, when it conducted at 45℃ under atmospheric pressure with volume space velocity of 1h^-1 and feed CS₂ concentration of 2000mg/L.