The paper aims to study the problem of obstacle avoidance in air?ground cooperative tracking control for the unmanned aerial helicopter (UAH),in which a new approach of designing the path obstacle avoidance plan and controller design is proposed.Initially, as for the uncertain linear UAH,by processing and judging two?dimensional environmental information within the warning range for the UAH,an obstacle avoidance strategy is proposed with the help of wall?following algorithm,and the flight angle of obstacle avoidance path and the tracking speed that can make up for bypass distance are calculated.Secondly,the proposed obstacle avoidance method is extended to the three?dimensional case,and the flight angle of the UAH is determined based on the obstacle information in the horizontal and vertical directions,which can reduce the bypass distance caused by the obstacle avoidance link as possible.Thirdly,based on two derived obstacle avoidance algorithms above,the artificial neural network (ANN) is introduced to estimate model uncertainty,and then the tracking control design schemes are established by using feedforward compensation and optimal control technologies.some simulations demonstrate the effectiveness of the proposed obstacle avoidance strategy and control algorithm.

The COVID?19 epidemic is facing the influence of a variety of complex practical factors, which makes the development of the epidemic uncertain. In order to overcome the problem of large error in epidemic forecasting results due to the limitations of many ideal assumptions based on the infectious disease compartment model, a time series forecasting model based on deep learning is adopted to predict the epidemic development, and an informer model based on transformer model is established. Attention mechanism and distillation mechanism are applied to the time series forecasting of epidemic data. The threshold autoregressive (TAR) model and a variety of mainstream recurrent neural time series prediction models are used as comparison models. Through simulation experiments, the current number of remaining infections in the epidemic data of China, America and Britain is predicted in the short term, and RMSE and MAE are used as evaluation indicators, and then the best model is selected for medium ? and long?term prediction. The experimental results show that the indicator value of the informer model is optimal in both RMSE and MAE, further indicating that the prediction accuracy of the informer model is higher than that of other comparative models in China, America and Britain. Finally, the Informer model is used for the development of the epidemic in China，America and Britain medium and long?term prediction.

With the improvement of environmental uncertainty, the demand for supply chain stability of petrochemical enterprises in China is rising day by day. The evaluation of supply chain resilience of petrochemical enterprises has become an important means to judge the risk coping ability of petrochemical enterprises. This paper constructs a supply chain resilience evaluation index system in the petrochemical enterprises. And fuzzy analytic hierarchy process and BP neural network are used to evaluate the toughness strength of petrochemical enterprise supply chain, so as to determine the toughness level of petrochemical enterprise supply chain.It is found that the strength of supply chain toughness of petrochemical enterprises is uneven, and the overall level of supply chain resilience is low. On the basis of the research results, some practical suggestions are put forward for the forging of resilient supply chain in petrochemical enterprises.

Magnetic tomography method has been widely used for nondestructive external inspection of buried and submarine pipelines, which is based on the principle of metal magnetic memory to discern the danger level and location of the stress concentration zone by measuring the anomalies in the spatial magnetic field distribution outside the pipeline. The distribution characteristics and spatial propagation law of pipeline inspection signal detected by magnetic tomography method, the energy distribution and change law of spatial magnetic memory signal in the stress concentration zone of magnetized pipelines are studied in this paper. The magnetic dipole field is used to establish the magnetic field model in the stress concentration zone of the inner wall of the pipeline, and the magnetic energy and energy density of spatial magnetic memory signals under different lift?off values outside the pipeline are finite element calculated based on the magnetic energy theory to derive the distribution law of spatial magnetic field and the correlation of magnetic energy density of magnetic signals under different lift?off value is analyzed. The results show that the spatial magnetic field energy outside the pipe decays with the increase of lift?off value, and the decay is the fastest within the distance of 50 mm from the outer wall of the pipe to the physical force; the correlation of magnetic energy density of different lift?off values shows that the magnetic signal detected by magnetic tomography method outside the pipe is homologous with the signal in the stress concentration zone of the inner wall of the pipe. Theoretically, it explains the effectiveness of magnetic tomography method and also provides evaluation indexes for extracting effective signals from the detection data.

Li₂ZnTi₃O₈ (LZTO) anodes of lithium?ion batteries have been prepared by a sol?gel method. The effects of the calcination temperature and time on the electrochemical performance have been studied for LZTO in detailed. The optimum calcination temperature and time are 700 ℃ and 3 h, respectively. On the basis of the optimum preparation process, citric acid as the chelating agent has been introduced into the synthesis to modify LZTO. When the molar ratio of metal ions to citric acid is 2.00∶1.50, the obtained product is denoted as LZTO?2/1.50, which has small particle size, good dispersion, and then shows good electrochemical performance. The discharge specific capacity is 203.6 mA·h/g after 300 cycles at the current density of 0.5 A /g for LZTO?2/1.50.

The data of chemical processes often contains dynamic timing characteristics, and traditional fault detection has low usage of dynamic information, which limits the fault diagnosis performance. To address this problem,a new method of chemical process fault diagnosis based on an attention?enhanced encoder?decoder network model (AEN) was proposed. The coding part uses the LSTM to extract the feature information of the process data and combine it with the attention mechanism to utilize the dynamic information among the process data more effectively； the decoding part uses the LSTM and combines the context vector provided by the attention mechanism to provide more accurate state information for the softmax regression, and finally, the softmax regression is used to obtain the probability value of the fault category for each sample data. The introduction of the attention mechanism improves the efficiency of the model in using process dynamic information in the time domain. The proposed method is experimented with using Tennessee Eastman process data and compared with the results of standard PCA?SVM, DBN and ResNet, and the results show that the proposed method is more effective in diagnosing faults.

Thiacalix[4]arene ligands have the advantages of high recognition, derivatization, excellent stability and other advantages. Lanthanide (Ln) ions can coordinate with thiacalix[4]arene ligands to form multi?functional coordination clusters, which received increasing attention due to their unique catalytic, magnetic, optical properties. Thiacalix[4]arene can sensitize Ln ions to luminescence by the coordination of phenol and S groups via the "Antenna effect". This paper reviewed recent advances in structures, luminescent properties, and applications of luminescent Ln?thiacalix[4]arene complexes.

The Fe/Mo ordering at B?sites of Ba₂FeMoO_6-δ (BFM) were changed by adjusting Fe/Mo amount of substance ratio (i.e., stoichiometric ratio), and then a new double?perovskite anode material Ba₂Fe_1.3Mo_0.7O_6-δ (BFM_0.7) for SOFC were obtained. The results indicated that the electrical conductivity of the BFM_0.7 anode is 15.0~20.0 S/cm at 600~800 ℃ in H₂, which is much larger than that of the lowest target for SOFC electrode (0.1 S/cm). The peak power density and polarization resistance of the BFM_0.7 anode cell attained 1 149 mW/cm² and 0.15 Ω·cm² at 850 ℃. Compared with BFM anode, the performance of BFM_0.7 is significantly improved. In addition, the performance of BFM_0.7 anode cell showed no degradation after testing for 39 h, indicating that the BFM_0.7 anode possesses has excellent electrochemical stability.

Monolayer Janus transition metal disulfides have low dimension, high mobility, and peculiar electronic structure properties, which have potential applications in electronics and optoelectronic devices. In devices made of monolayer Janus transition metal disulfide and substrate materials,are usually stressed due to lattice mismatch between monolayer Janus transition metal disulfides and substrate, it is significant to study the strain effect on physical properties of monolayer Janus transition metal disulfides through Raman scattering.This paper systematically investigate the biaxial strain effect on the atomic structure, electronic structure and Raman spectra of monolayer Janus MoSSe. The results show that monolayer Janus MoSSe can exhibit a band gap transition from direct to indirect one under biaxial strain, due to both the energy shift of bonding orbitals between the top of the valence band and the bottom of the conduction band and the sensitivity to strain. This paper also thoroughly study the strain effect on the Raman shift and intensity of monolayer Janus MoSSe. It is found that under biaxial strain modulation from decreasing compressive to increasing tensile, for the Raman shift, the three peaks of E¹, E², and A {}_{\mathrm{1}}^{\mathrm{1}} red?shift, while the peak of A {}_{\mathrm{1}}^{\mathrm{2}} blue?shifts abnormally with decreasing compressive strain; for the intensity, the peak intensity of the doubly?degenerate modes (E¹,E²) increases monotonically, while singly?degenerate modes shows the opposite trend, except for the A {}_{\mathrm{1}}^{\mathrm{1}} which intensity decreases with decreasing compressive strain and then increases with tensile strain. This paper propose a simple model to comprehend the strain effect. This theoretical study may supply an effective means to quickly and quantitatively characterize the strain size and type in Janus materials through the frequency difference and intensity ratio between typical Raman peaks.

In view of the irregularity of the bottom floor of working face and the diversity of the shape of the flying gangue in steeply dipping coal seam, based on the geographic information system data such as contour line of bottom floor of working face, the 3d grid model of bottom floor is established, combined with the energy tracking method(ETM) C + + programs, four typical shapes of flying gangue with the same mass and different shapes are simulated to obtain the motion trajectories of the migration of flying gangue in the actual working face, as well as the velocity, angular velocity and energy change curves at any time. The influence of the shapes on the motion of flying gangue is analyzed. In order to verify the accuracy and feasibility of the method in this paper, the trajectory simulated by Rockyfor3D software is compared. The results show that the transport capacity of ellipsoidal flying gangue is much higher than that of polyhedral flying gangue. Compared with common polyhedral flying gangue, the regular polyhedral flying gangue has farther migration distance and less energy loss due to collision. The number of edges of flying gangue of regular polyhedron is inversely proportional to the energy loss of flying gangue in collision, which indicates that flying gangue of regular polyhedron with multiple edges is most likely to cause danger．

Pollution caused by petroleum?based plastic products has become a problem that is difficult for human beings to solve, and the existing treatment methods are both energy?consuming and easy to cause secondary pollution. The study found that the bacteria that degrade plastic in the intestines of Galleria mellonella (Lepidoptera: Pyralidae) larvae can effectively accelerate the degradation of plastics. This experiment uses polystyrene (PS) packaging boxes, which are common in life, as the only food source to feed the larvae of the large wax borer, enriching the PS?degrading bacteria in the intestines of the G. mellonella larvae. After dissection, culture, and isolation, four strains were obtained: PD?1, PD?2, PD?3 and PD?4. The degradation capacity of MSM culture medium with PS film as the only carbon source was inoculated with each strain, and the degradation rate of PD?1 on PS film was the highest, which was 1.8%. PD?1 was observed by strain morphology, physiological biochemical determination and phylogenetic tree construction, and it was identified as Enterobacter colebella (Klebsiella). Meanwhile, the method of UV and nitric acid pretreatment of PS film were used to improve the degradation rate of the strain, and the results showed that the weight loss rate of PD?1 degradation of nitric acid?treated PS film was improved, which was 2.5%, while the UV group was 0.8%, indicating that PS film was more easily degraded by PD?1 after nitric acid treatment.

Recognition of weather phenomena based on images is essential for the analysis of weather conditions. To address the problems that traditional machine learning methods are difficult to accurately extract various weather features and poor in classifying weather phenomena and the accuracy of deep learning for weather phenomena recognition is not high, a weather recognition model based on image block and multi?headed attention mechanism is proposed. The model introduces Swin Transformer into the field of weather recognition for the first time, and adopts a multi?headed attention mechanism combining window multi?head self?attention layer and shifted?window multi?head self?attention layer, whose regionally relevant features extraction capability makes up for the shortcomings of traditional methods and can extract complex weather features from images. The model is trained using transfer learning, and the fully connected parameters of the fine?tuned model are input to the Softmax classifier to achieve recognition of multi?category weather images with 99.20% recognition accuracy, which is better than several mainstream methods in comparison, and it can be applied to ground weather recognition systems as a weather recognition module.

Polylactic acid/Poly(butylene adipate?co?terephthalate)/Poly(methyl methacrylate)?b?poly (butyl acrylate)?b?poly (methyl methacrylate)ternary blends (PLA/PBAT/MAM) were prepared by melt blending, and the effect of MAM relative molecular weight on the morphology, structure and properties of the blends was investigated. The results showed that the addition of MAM block copolymer can inhibits the crystallization of PLA，improve the compatibility of PLA/PBAT, reduce the particle size of the dispersed phase and make the distribution more uniform, improve the impact properties and elongation at break of the blends. And the relative molecular weight of MAM increased, the impact strength and elongation at break of the blend increased, the smaller the size of the dispersed phase particles, and the more uniform of particle size distribution.

Gasoline molecular blending technology on?line requires rapid access to detailed molecular composition information of various types of component oils. In this paper, an autoencoder?based method for the rapid resolution of gasoline molecular composition is developed, which can directly predict the detailed monomeric hydrocarbon composition of gasoline from near?infrared spectra. The constructed autoencoder model of gasoline molecular composition can explore the potential features and recover the original molecular composition by decoding the potential features. The artificial neural network algorithm is used to correlate the NIR spectral information with the potential features of gasoline composition. The accuracy of the model is verified by using hydrogenated gasoline with the average absolute error is 0.033. The model developed in this work applies the current popular autoencoder algorithm to the traditional petrochemical process, which is an important guideline for blending online and real?time optimization of gasoline molecules.

Billets have oxidized layers and defects on their surface due to the production process, so they must be surface?regulated by grinding. There is no special equipment for surface regrinding of large square steel billets; a square steel regrinding equipment was designed. Kinematic simulation verification was completed using ADAMS software. The results show that the regrinding equipment can simultaneously and smoothly complete the grinding operation on two adjacent surfaces. Using finite element software ANSYS to carry out stress analysis and modal analysis of the regrinding machine under load, and improve the structure; according to the simplified kinematic model, static analysis was carried out to get the required input driving torque, and the selection of the critical components of the spring was completed. Theoretical calculations and simulation results show that this regrinding machine can efficiently grind the surface of large square billets.

Aiming at the bond?slip behavior of reinforced concrete, the finite element model of reinforced concrete bond?slip based on cohesion model was constructed by ABAQUS finite element software. The mesh sensitivity and cohesion parameter sensitivity of the simulation model were explored by energy and load?displacement curves. Aiming at the problem of bond strength of reinforced concrete, a nonlinear autoregressive exogenous network (NARX) was developed to predict the load?displacement curve for reinforced concrete by creating 20 sets of data with the variables of bond length, reinforcement diameter, and loading method. The study shows that the mesh size of 6 mm provides an ideal balance between prediction accuracy and computational cost. Based on the sensitivity of the finite element prediction results, the cohesive parameters are in the sequence of damage initiation strength, fracture energy, and stiffness. The NARX with the prediction accuracy of 99.6% is promising to replace time?consuming numerical simulations and experimental works to achieve an efficient and accurate prediction of the bond strength of reinforced concrete. Such an efficient and accurate prediction method provides a novel and convenient methodology of predicting and designing the bond strength of reinforced concrete.

The direct method was used to prepare polyurea lubricating grease, and the effects of several different types of additives on the extreme pressure and anti?wear performance for polyurea lubricating grease were investigated and studied. The results demonstrate that several types of additives have good compatibility with polyurea grease, and they have little undesirable influence on colloidal stability of polyurea grease, and they can also enhance thermal stability of polyurea grease. Moreover, the addition of additives can significantly improve the performance of extreme pressure and wear resistance for polyurea lubricating grease. And in the experiments, it was found that the composite multifunctional additive containing sulfur and phosphorus has a relatively better effect on improving the extreme pressure and wear resistance of polyurea lubricating grease. The research results can provide a reference basis for the improvement of extreme pressure and anti?wear property for polyurea lubricating grease, achieving a relatively optimized comprehensive performance, thereby enhancing its practical utilization performance under the harsh working conditions for high load and high speed mechanical equipment.

In order to study the influence of cross?fracture on the mechanical properties and damage modes of deep shale, and better understand the damage evolution law of shale containing cross?fracture under high temperature and high pressure coupling, 15 groups of shale models containing cross?fracture with different inclination angles were established, and simulation experiments were carried out to study the stress?strain relationship, damage evolution and acoustic emission characteristics of the shale specimens. The results show that the compressive strength and modulus of elasticity of shale are negatively correlated with the inclination angle of the main cracks, and show an upward concave trend with the increase of the inclination angle of the secondary cracks, and the compressive strength of shale decreases significantly when there are cracks perpendicular to or close to perpendicular to the loading direction; the damage modes of shale specimens under the influence of cross?cracks are mainly divided into "X"?shaped damage, diagonal "N"?shaped damage, diagonal "W"?shaped damage, inverted "V"?shaped damage, damage along the main crack, "V"?shaped damage and "λ"?shaped damage; the fractal dimension of shale specimens is negatively correlated with the inclination angle of the main crack, and as the inclination angle of the main crack decreases, the value of fractal dimension tends to increase, and the corresponding damage pattern of the specimens is more complicated and the internal damage is more intense.

In order to understand the mechanism of CO₂ dissolved buried mechanism in high temperature and high pressure porous environment,physical simulation experiment was conducted to study CO₂ dissolved buried mechanism,mineralization buried mechanism and free buried mechanism in porous media by means of indoor physical model experiment.The results show that the solubility of CO₂ in formation water is mainly affected by temperature, pressure and salinity of formation water. CO₂ dissolved in formation water will mineralize with minerals in rocks, and the mineral content of rocks will change significantly before and after the reaction. The long core displacement experiment characterized the amount of free CO₂ storage and the oil displacement effect. The experiment reveal that CO₂ flooding in porous media has dual effects of burying and enhancing oil recovery.

Aerobic oxidative desulfurization is a safe and environmentally friendly desulfurization method, but oxygen usually needs to be activated under harsh conditions, the synthesis of efficient catalyst is an effective way to improve desulfurization activity. In this work, flower?like cobalt molybdate with large specific surface area was synthesized by one?step hydrothermal method using cobalt chloride and ammonium molybdate as raw materials. In addition, urea is used as precipitation agent and structure control agent. The morphology and structure of the CoMoO₄ were characterized by FT?IR, XRD, SEM, XPS and N₂ adsorption desorption techniques. Dibenzothiophene in simulated oil was removed using CoMoO₄ as catalyst and molecular oxygen as oxidant. The effects of reaction temperature, the flow of oxygen, the amount of CoMoO₄ and the type of sulfur compounds on the desulfurization rate were investigated. In addition, the recycling performance of flower?like CoMoO₄ was studied. The experiment shows that the desulfurization rate can reach 98.2% under the optimal reaction conditions. The catalyst can be reused for 5 times without significant reduction in oxidative desulfurization activity. The formation of superoxide radical in the oxidation desulfurization process resulting in high desulfurization activity.

A new type of Ruddlesden?Popper cobalt?rich layer perovskite oxide La_1.5Ca_0.5Ni_0.2Co_0.8O_4+δ (LCNC) was synthesized by a sol?gel process. The results show that the conductivity of LCNC in air at 400 ℃ to 800 ℃ is 4~58 S/cm, which is better than that of most reported SOFC cathode materials. The polarization impedance of symmetrical battery LCNC|LSGM|LCNC is 0.16 Ω·cm² at 800 ℃. The maximum power density of the single cell supported by 300 μm thick La_0.9Sr_0.1Ga_0.8Mg_0.2O_3-δ (LSGM) with the LCNC cathode was 527 mW/cm², and the performance of the single cell decreases slightly after working continuously for 50 hours. The experimental results show that LCNC is a potential SOFC cathode material.

As an electrochemical inert cation, Mg²⁺ has an ionic radius (0.072 nm) similar to that of Li⁺ (0.076 nm), which is widely used to replace Li⁺ in Li?rich layered oxides (LLOs) materials. However, the influence of Mg²⁺ on the crystal structure of LLOs materials is still controversial. In this work, the Mg?doped Li?rich cathode materials Li_1.2-x Mg _x Mn_0.54Ni_0.13Co_0.13O₂ were synthesized by a sol?gel and high?temperature calcination method. The crystal structure, and valence state of elements in synthesized materials were systematically studied via X?ray diffraction, and X?ray photoelectron spectroscopy. These results indicated that Mg²⁺ doping can increase the cell parameters of LLOs materials. At the same time, compared with Li_1.2Mn_0.54Ni_0.13Co_0.13O₂, Mg?doping can effectively improve the electrochemical performance of LLOs materials. After optimization, the Mg?0.03 sample exhibits anomalous electrochemical performance, that is, the initial discharge?specific capacity is 291.9 mA?h/g and the initial coulomb efficiency is 78.40%.

In recent years, the rapid expansion of industries such as new energy has significantly heightened the demand for lithium resources. China boasts ample lithium reserves; however, 80% of these reserves are concentrated in salt lake brine, and the high magnesium?to?lithium ratio inherent in salt lakes poses challenges for lithium extraction. To ensure a stable supply of lithium resources in our country, it is imperative to develop cost?effective and highly efficient technologies for lithium extraction from salt lakes. Recent studies have demonstrated that the combination of emerging membrane separation technology with traditional processes holds great potential for achieving significant advancements in lithium extraction from salt lakes. This review aims to present the latest membrane technologies for extracting lithium from salt lake brine. It comprehensively discusses cutting?edge research findings from various perspectives, including the pore structure of membrane, precise design of the chemical environment within the pores, development of innovative membrane fabrication processes, and the integration of multiple membrane processes. By doing so, the review offers valuable insights and guidance for the design of new membrane materials. Furthermore, the review provides a comprehensive overview of the current bottlenecks faced by membrane separation technology in the process of lithium extraction from salt lakes. It also explores the potential prospects of biomimetic membrane materials.

This paper compared the variation trend of the output and consumption of diesel and the difference of the qualities of different sources diesel with the standard of Ⅵ diesel in China, and analyzed the composition, quality and problems of diesel pool in detail. It is considered that the most important problems in diesel quality upgrading process is how to reach the standard of diesel density and cetane number (including cetane index), rather than diesel sulfur content. Therefore, some countermeasures were put forward, such as identify the difference between cetane number and cetane index, optimizing crude oil processing, hydro?converting inferior diesel and adjusting the product structure of refinery.

Nickel?based superalloys, as typical difficult?to?machine materials, are widely used in aerospace engines, chemicals, ships, and other fields. To meet the special working conditions requirements of the aero?engines, and further improve the surface machining quality and processing efficiency, relevant researchers have carried out many theoretical studies and process explorations. The development of nickel?based single crystal superalloys and polycrystalline superalloys, and their material properties were firstly reviewed. Then the main research results of domestic and overseas scholars on the grinding removal mechanism, grinding surface integrity, and process characteristics of nickel?based superalloys were summarized, and their development trends are prospected.

A waterborne polyacrylate colloid with hard core and soft shell structure was synthesized with methyl methacrylate (MMA), styrene (St), butyl acrylate (BA), methacrylic acid (MAA) as monomers, diacetone acrylamide (DAAM) as crosslinking monomer and adipic acid dihydrazide (ADH) as crosslinking agent. By adjusting the glass transition temperature (T_g), the emulsion can be self?forming film without adding film forming additive at room temperature. The influence of DAAM?ADH crosslinking system on the properties of latex films was investigated. DSC and TGA analysis showed that the T_g and thermal stability of crosslinked latex films are higher than those of uncrosslinked films. When the mass ratio of DAAM in core?shell is 1∶2, the comprehensive performance of latex films is better than that distributed in core or shell alone. With the increase of DAAM content, the water absorption decreased from 18.99% to 4.38%, and the Gel Fraction increased from 79.30% to 90.84%. When the molar ratio of ADH/DAAM is 1.25, the water absorption reaches the lowest and the Gel Fraction reaches the maximum.

As a new type of clean, carbon?free, sustainable and efficient energy source, hydrogen has great potential in the future energy mix. Hydrogen purification by pressure swing adsorption is the main separation technology for hydrogen production with high purity, low energy consumption and high degree of automation. In this paper the progress in research and application of pressure swing adsorption hydrogen production in theoretical simulation, process control optimization and adsorbent materials were critically reviewed, and the future development of pressure swing adsorption hydrogen production technology was prospected.

In this paper, a kind of composite phase change material (capric?lauric acid/expanded vermiculite) using expanded vermiculite as the matrix and capric?lauric acid binary eutectic as the adsorbent was fabricated by vacuum impregnation technology. The chemical compatibility, morphology, stability，thermal?physical properties and reliability of the prepared composite capric?lauric acid/expanded vermiculite were investigated by fourier transform infrared spectrum (FT?IR), scanning electronic microscope (SEM), thermal gravimetric analyzer (TGA), differential scanning calorimeter (DSC) and thermal cycling test. The melting and solidification phase transition temperatures of capric?lauric acid/expanded vermiculite are 18.42 ℃ and 17.51 ℃, respectively. The latent heat of melting and solidification phase transition are 66.9 J/g and 62.9 J/g, respectively. Besides, the encapsulation amount of capric?lauric acid in expanded vermiculite can reach 52.97%, and it has good thermal stability between working temperature. Moreover, the capric?lauric acid/expanded vermiculite was used to substitute for a certain proportion of fine sand to prepare thermal storage mortar, the mechanical and thermal performance of capric?lauric acid/expanded vermiculite?based mortar was evaluated. The test result shows that prepared capric?lauric acid/expanded vermiculite?based thermal storage mortar is a potential material for building heat regulation and energy saving.

This paper uses Aspen Plus software to carry out steady?state simulations of a new process for the reactive distillation of hydrogen peroxide isopropylbenzene (CHP) and subsequent refining processes for phenol and acetone. The operating pressure, feed position and number of plates of the reactive distillation column and the refining process were economically optimised with the objective of minimising the total annual cost (C_TAC). The results show that the optimal operating parameters of the process are as follows : the total number of trays of RD was 34, the number of trays in the distillation section was 27, the number of trays in the reaction section was 6, the feed position was 28, and the operating pressure was 3.0×10⁴ Pa. The total plate numbers of acetone refining tower (T101), cumene top tower (T102), tar tower (T103) and phenol refining tower (T104) were 25, 61, 23 and 22, respectively. The feed positions are 16, 45, 9 and 9, respectively. The operating pressures were 5.2×10⁴, 5.0×10³, 5.5×10⁴, 6.0×10³ Pa. The minimum C_TAC of the new process was 2 239.03×10⁴ yuan/year. At the same time, the steady?state simulation and economic optimization of the traditional CHP decomposition and subsequent phenol and acetone refining process were also carried out, and the minimum C_TAC value was 2 608.13×10⁴ yuan/year. By comparing the reactive distillation process with the traditional process, it can be seen that C_TAC can save 14.15% and energy consumption can save 9.01%.

TiO₂/Fe₂O₃ nanocomposites with different morphologies were prepared by precipitation separation method combined with sol?gel method using Fe(NO₃)₃?9H₂O and tetrabutyl titanate as iron and titanium sources, and HF, HAc, NH₄F, NH₃?H₂O, H₂O₂ as morphology control agents, respectively. The structure and morphology of the TiO₂/Fe₂O₃ samples were characterized by X?ray powder diffraction (XRD) and field emission scanning electron microscope (FESEM), and the degradation performance of the TiO₂/Fe₂O₃ nanocomposites for methylene blue under UV?light irradiation condition was investigated. The results show that the NH₃?H₂O?TiO₂/Fe₂O₃ nanocomposites prepared with NH₃?H₂O as the morphology control agent have the best degradation effect on MB, with a degradation rate of 82.9%, which is approximately 1.00, 1.10, 1.14, 1.15, 1.56, 3.57, 12.95 times larger than that of HF?TiO₂/Fe₂O₃ (82.5%), H₂O₂?TiO₂/Fe₂O₃ (75.7%), NH₄F?TiO₂/Fe₂O₃ (72.9%), HAc?TiO₂/Fe₂O₃ (71.8%), TiO₂ (53.1%), Fe₂O₃ (23.1%) and blank (6.4%) samples, respectively. This is attributed to the synergistic effect of its large specific surface area, spindle morphology, highest crystallinity and suitable heterojunction structure.

Due to the high storage capacity and multiple electron?transfer chemistry of sulfur (S), Li?S battery with virtues of high theoretical capacity/energy density, eco?friendliness and abundant supply has been considered as one of the most promising candidates for next?generation battery systems. The capacity of Li?S battery is much higher than that of traditional metal oxide cathode?based lithium?ion battery, which is regarded as the highest capacity of solid?state cathode?materials at current stage. As a vital component of Li?S battery, separator plays a profound role in resolving crucial issues (e.g., shuttling effect, volume expansion, poor conductivity and metal dendrites, etc.) of Li?S battery. So far, some pioneering works have been reported in the exploration of separators for Li?S battery. On this basis, covalent organic frameworks (COFs), possessing the advantages of low density, high porosity, well?defined structure, designable structure and functions, is a kind of potential materials for the functional modification of Li?S battery separators. This review will summarize the reported works about COFs in Li?S battery separators including their structural characteristics, preparation?methods, application forms and battery properties. It will also provide a brief perspective for the applications of COFs in Li?S battery separators and hope that it might give new insights for scientists in related fields.

The effects of polymerization reaction temperature, polymerization reaction time, catalyst and crosslinker addition on the properties of modified ethylene tar pitch (METP) were investigated, and the optimal reaction conditions were obtained by combining elemental analysis, FT?IR, XRD, Raman and thermogravimetric analysis on ETP and METP: The polymerization reaction temperature was 370 ℃, and the polymerization reaction time was 6 h, besides the addition of catalyst and crosslinker was 1.50%. The softening point (SP) of METP obtained under these conditions was 182 ℃, the coking value (CV) was 57.66%, the β resin was 42.26%, and the quinoline insoluble matter (QI) was 0.87%, which met the requirements of high carbon material precursors； The yieid of METP was 73.26%.

The study of ultrasonic variable amplitude rods is an important part of ultrasonic vibration system. The cosine half?period cylindrical composite horn was designed to realize the smooth transition between the cosine section and the cylindrical section. By theoretical calculation, its frequency equation and amplification coefficient equation were derived. The results show that the frequency equation of the new cosine cylindrical composite variable amplitude rod is simpler than that of the cylindrical conical composite variable amplitude rod and the stepped variable amplitude rod; the amplification coefficient equation of the new cosine cylindrical composite variable amplitude rod is similar to that of the stepped variable amplitude rod, which is more concise than that of the cylindrical conical composite variable amplitude rod. Using ABAQUS finite element analysis software, modal analysis of the designed cosine cylindrical composite variable amplitude rod was carried out to determine its inherent frequency and vibration type; harmonic response analysis was conducted to check the feasibility of the theoretical design. The results of the modal analysis and harmonic response analysis show that the performance of the ultrasonic composite variable amplitude rod is optimal when the length of the cosine section is 55 and 60 mm. The research results provide a reference for the design and application of ultrasonic composite amplitude rod.

Oily sludge has been classified as hazardous waste because of its complex composition， high stability and difficult treatment. At present， the treatment technologies of oily sludge include landfill， solvent extraction， thermochemical cleaning， ultrasonic assisted treatment and biological treatment. Among them， the thermochemical cleaning technology has the advantages of easy operation and high reliability， and the key technology lies in the selection of cleaning agent. Different types of single cleaning agents are introduced， including inorganic sal cleaning agents， chemical surfactants and biological surfactants. This paper classifies and summarizes the compound of different types of single cleaning agents， and focuses on the mechanism of the compound of non?ion?anionic surfactant， non?ion?non?ionic surfactant， alkaline inorganic salt?surfactant and biological surfactant. Based on this， the development direction of thermochemical cleaning agent is prospected in order to improve the cleaning effect of oily sludge.

To investigate the structure?function relationship of novel extended surfactants and the mechanisms of reducing interfacial tensions (IFTs) at oil?water interface, the interfacial tension values of 13?P series 13?P（I?C₁₃（PO） _x S,x=5,10,15,20）with different concentrations of NaCl and n?hexane to n?tetradecane at fixed concentration were measured by rotary drop interfacial tension meter. The result indicates that at higher numbers of PO（x=15,20), the n_min values become higher with increasing concentration of NaCl. At lower numbers of PO（x=5,10), the n_min values become lower with increasing concentration of NaCl. It reflects two mechanisms on reducing IFTs: Hydrophilic lipophilic equilibrium effect and hydrophilic hydrophobic group in size matching effect, both of which work together, and the size matching plays a crucial role at lower numbers of PO and HLB dominates at higher numbers of PO.

The coking kerosene fraction was used as the raw material for the experiment. The linear α?olefins in the raw oil were enriched by complex extraction method, and the high viscosity poly α?olefin base oil (PAO) was synthesized by oligomerization. The effects of temperature, time and catalyst dosage on the properties of PAO were investigated. The kinematic viscosity, viscosity index and PAO yield rate at 100 ℃ were determined. Under the optimum process conditions of catalyst mass fraction of 6%, polymerization temperature of 25 °C, polymerization time of 8.0 h, addition polymerization temperature of 80 °C and addition polymerization time of 2.0 h, the reaction effect is the best: The kinematic viscosity of PAO at 100 ℃ is 43.54 mm²/s, the viscosit index is 163, the freezing point is -50 ℃, and the flash point is 291 ℃. The yield is 85.48%. Compared with the PAO40 standard, the obtained product is a high viscosity lube base oil.

Citric acid type deep eutectic solvent was synthesized using citric acid（CA） and choline chloride (ChCl) as raw materials. The existence of hydrogen bonding in deep eutectic solvents (DESs) was determined by infrared spectrum and hydrogen spectra. Sulfide in simulated oil was removed using DESs as extractant and potassium bisulfate as oxidant. The effects of the amount of water, the amount of oxidant, the ratio of hydrogen bond donor and acceptor, reaction temperature and different sulfides on desulfurization rate were investigated, and the optimum reaction conditions were determined. The results showed that the removal rate of DBT in simulated oil was 98.50% at V（model oil）=5 mL, n（ChCl）/n（CA）=1.0∶0.5, V（DES）=2.0 mL, T=30 ℃, m(catalyst)=0.6 g, m(water)=0.4 g. After five times of recycling, the desulfurization rate remains above 95.00%.

Metal nanomaterials with high thermal conductivity are ideal promoters for enhanced gas hydrate formation, including metal?based nanoparticles, metal oxides, and metalloid oxides. In this paper, the effects of different kinds of metal nanomaterials on the formation of gas hydrates were reviewed, and the effects of parameters such as the induction time and gas consumption of enhanced hydrate formation were introduced from the three aspects of additive concentration, particle size and surface properties. The results show that the heat transfer effect of metal?based nanoparticles is better, and some metal oxides and metalloid oxides will exhibit an inhibitory effect; the appropriate addition concentration and particle size have an important impact on the formation of hydrates. In addition, the combination of metal nanomaterials and chemical reagents can significantly improve the dispersion stability of nanoparticles, thereby promoting the efficient generation of hydrates.

The vibration signal during the operation of high voltage circuit breaker can reflect the mechanical state of circuit breaker. Aiming at the shortcomings of feature extraction and fault diagnosis accuracy of shallow vibration signal analysis model, a fault diagnosis method of high voltage circuit breaker based on convolutional neural network optimized by genetic algorithm was proposed. Using the global optimization ability of genetic algorithm, the optimal initial network structure parameters and the number of neurons in the whole connection layer were obtained through the selection, crossover and mutation of genetic algorithm to optimize the convolutional neural network, and the optimized convolutional neural network is applied to the fault diagnosis of high voltage circuit breaker. The results show that the diagnosis performance of the proposed network model is better than that of convolution neural network, dynamic support vector machine and multilayer perceptron.

Carbon capture, transport and storage (CCS) plays an important role in the process of carbon neutralization. The flow and heat transfer process of supercritical CO₂ and supercritical CO₂ mixture in a vertical circular tube was studied with supercritical CO₂, supercritical CO₂+CH₄ mixture (CH₄ mole fraction is 1%, 3%, 5%) and supercritical CO₂+N₂ mixture (N₂ mole fraction is 1%, 3%, 5%) as working fluids at a mass flow rate of 300～600 kg/(m²?s), heat flow density of 80～100 kW/m², and inlet pressure of 8～10 MPa. The results show that with the decrease of CH₄ and N₂ mole fraction in the working medium, the peak value of heat transfer coefficient of the working medium increases gradually, and its corresponding temperature increases gradually; the heat transfer coefficient of the working fluid increases with the increase of the mass flow rate, and the greater the mass flow rate, the greater the change range of the heat transfer coefficient; with the increase of inlet pressure, the peak value of heat transfer coefficient of working fluid decreases, and its corresponding temperature increases gradually. Turbulent kinetic energy, buoyancy and specific heat capacity at constant pressure are closely related to the heat transfer enhancement of supercritical CO₂ and its mixture.

A mononuclear Cu complex Cu_0.5(4,4'?bipy)(H₂O)·L·0.5(4,4'?bipy)·2H₂O (1) was obtained by hydrothermal reaction with Cu²⁺ as the central ion and 4,4'?bipy as the nitrogen?containing auxiliary ligand. Its structure and composition were characterized by modern characterization methods, such as X?ray single crystal diffraction, elemental analysis and infrared spectrum. The results show that Cu²⁺ is six coordinated with four nitrogen atoms of 4,4'?bipy molecules and two oxygen atoms of H₂O molecules, showing a distorted octahedral coordination configuration. L^2- anion only balances the positive charges in compound 1 and does not participate in the coordination of metal Cu²⁺. Cu²⁺ coordinates with 4,4'?bipy and H₂O molecules to form a lattice layered structure [Cu(4,4'?bipy)₂(H₂O)₂]²⁺, the hydroxyl group of L^2- anion and free H₂O molecules form hydrogen bonds with H₂O molecules in the layered structure respectively, which increases the thermal stability of H₂O molecules in compound 1. The fluorescence emission of compound 1 is at 409 nm, which can be attributed to the intraligand emission state. Compared with the ligand, there is a slight red shift, which may be caused by the coordination between 4,4'? bipy ligand and Cu²⁺.

Aiming at the problem of insufficient representation of interactive semantic information in the double human interaction behavior recognition method based on graph convolutional neural networks，a new double human interactive spatial?temporal graph convolution network (DHI?STGCN) was proposed for behavior recognition. The network contains spatial sub?network modules and temporal sub?network modules. Based on the 3D skeleton data obtained from the interactive action video, a spatial action graph of double human interactive action was generated for the representation of spatial information. In the graph, the connecting edges between double human were given different weights according to the joint point position information. The connection of context time information was added in the constructed adjacency matrix, and the joint points in the graph were connected with their nodes within a certain time range in time information processing. The generated spatial?temporal graph data was sent to the spatial graph convolution network module, and the temporal graph convolution network module was combined to enhance the continuity of inter frame motion features for modeling in time. The model fully considers the close relationship of double human interaction. The comparative experimental results on NTU?RGB+D dataset show that the algorithm has strong robustness and obtains better interaction recognition effect than the existing models.

Grinding technology with minimum quantity lubrication technology is a new type of environmentally friendly and efficient processing technology. It has the characteristics of less cutting fluid and low cutting force, and is conducive to the maintenance of the tool and can effectively improve the quality of the workpiece. However, the cooling performance of the high?pressure air flow of the grinding technology with minimum quantity lubrication is very limited, which can not meet the need for cooling in the grinding zone. The traditional casting cooling technology can meet this demand by using a large amount of grinding fluid. In this paper, the research background, development status and latest achievements of micro?lubrication technology were reviewed, which lays a theoretical foundation for further study of the characteristics and principles of these special grinding technology with minimum quantity lubrication..

The types of volcanic rock reservoir space, reservoir physical properties and the main controlling factors were systematically studied by the method of reservoir physical property experiment, core casting thin section observation and X?ray diffraction test. The results show that the Yingcheng formation volcanic rocks in the Dehui fault depression have strong alteration, and the reservoir space is dominated by dissolution pores and dissolution fractures. The average porosity of tuff and dacite are 12.40% and 7.47%, respectively, and the permeability is less than 1.000 mD, belonging to type Ⅲ reservoirs. Gas?bearing formations can be further identified based on acoustic and resistivity logging methods. Lithology and lithofacies are the main controlling factors for the development of reservoirs, and lithofacies models of extrusive facies, extrusive facies and explosive facies were established in combination with the characteristics of seismic reflections. It provides an important theoretical basis for clarifying the mechanism of volcanic rock formation and the distribution of reservoirs in the study area.

In order to explore the microscopic mechanism of wax deposition on the pipe wall of high temperature and high?pressure condensate gas wells, this paper uses molecular dynamics simulation technology by the Materials Studio to build condensate oil system with methane, pentane, nonane,n?dodecane, cyclobutane, cyclopentane, benzene and toluene,and the wax component model was built with n?octadecane, and simulate with wax content, asphaltene and scale as variables. The results show that with the increase of wax and asphaltene mass fraction, the wall wax deposition behavior can be intensified, but when the asphalt mass fraction reaches 2.0%,the wall wax deposition behavior can be inhibited.The more kinds of heteroatoms in asphaltene,the more obvious the promotion effect.When there is scale on the pipe wall, sulfate scale has a great influence on wax deposition.The understanding of microscopic mechanism provides a scientific basis for the treatment of wax deposition on the pipe wall.

A double polyoxometalates?based composite catalyst material was prepared by Mechanochemistry. In order to compare with the double polyoxometalates?based composite catalyst material, one polyoxometalates?based were prepared by the same method. The structures of these catalysts were characterized by X?ray powder diffraction, Fourier transform infrared spectroscopy, and liquid ultraviolet spectroscopy. The photocatalytic degradation of rhodamine B (RhB) was selected as a model reaction to evaluate its photocatalytic activity and the possible mechanism were further explored in the degradation process. The results indicate that the degradation efficiency of H₃PMo₁₂O₄₀&H₄SiW₁₂O₄₀@MOF?199 is 92% while irradiating in simulated sunlight for 60 minutes, which is superior to that of the corresponding single POMs catalysts H₃PMo₁₂O₄₀ or H₄SiW₁₂O₄₀@MOF?199 and has a good cycling activity. The synergistic effect of the good photocatalytic activity of polyoxotungstates and the good oxidation?reduction ability of polyoxomolybdates, which provides a new vision for designing diverse POMs@MOFs composite catalysts with different catalytic properties.

Using corn straw as raw material of biochar and modified with chitosan and rare earth, chitosan?lanthanum chloride?biochar composites and chitosan?cerium chloride?biochar composites were prepared respectively. The structure and performance of CBC?La and CBC?Ce were analyzed by XRF, FT?IR and XRD. The adsorption properties of Cr(Ⅵ) in water under different adsorption conditions were investigated. The experimental results show that the Langmuir equation can simulate the isothermal adsorption behavior well, and the quasi?first?order kinetic equation has a higher fitting degree. The theoretical equilibrium adsorption capacity are 21.08 mg/g and 19.16 mg/g, which is close to the actual value. The desorption experiments show that CBC?La and CBC?Ce had the possibility of reuse. The adsorption mechanism mainly includes electrostatic adsorption, complexation and ion exchange. The experimental results show that the chitosan?rare earth?biochar composite material has a good application prospect in the removal of Cr(Ⅵ) from water.

In the context of the shipping industry emission reduction target set by the International Maritime Organization and based on the current situation of carbon reduction in the shipping industry, this paper introduces the development history and emission reduction advantages of hydrogen powered ships, analyzes the hydrogen storage methods of hydrogen powered ships at home and abroad and the safety risks of hydrogen energy onboard, and compares the technical advantages and onboard feasibility of various Marine hydrogen storage methods. It is concluded that the hydrogen production technology of shipboard methanol steam reforming is of great significance to solve the hydrogen safety problem of hydrogen?powered ships. At last, the problems faced in developing hydrogen?powered ships with shipboard hydrogen production units are put forward.

In the research on the thermal efficiency of atmospheric tube heating furnaces, it is necessary to conduct effective online measurement of thermal efficiency and select relatively reliable advanced control methods. On the basis of the research on the combustion mechanism of the heating furnace, the online measurement method based on the principle and data processing is used to process the thermal efficiency, and the "dynamic matrix control" is introduced in the process of optimizing the control of the heating furnace efficiency, which is compared with the traditional control method. The introduction of dynamic matrix control makes the system have a better control effect. At the same time, the "particle swarm algorithm" was selected to optimize the parameters of dynamic matrix control. In the optimization process of dynamic matrix parameters, the particle swarm algorithm relatively shortens the optimization time and improves the control quality, so as to achieve a more satisfactory control effect. Finally, compare with internal model control, it shows that dynamic matrix control can achieve relatively better control effect.