With the development of renewable energy sources,emerging energy storage systems have received a lot of attention. Sodium-on batteries have attracted extensive attention in the field of large-scale energy storage due to their abundant sources, safety,low cost,environmental friendliness and ease of use.The cathode materials of sodium-ion batteries affect the key properties of the battery such as energy density,cycling performance and multiplication characteristics.Currently,three cathode materials for sodium ion batteries have entered the industrialization horizon,namely layered transition metal oxides,polyanionic compounds and Prussian blue compounds.This paper summarizes the classification,properties,and research progress of main cathode materials for sodium-ion batteries,and anticipates the prospect of the potential research.

In the context of addressing the energy crisis and realizing environmental sustainability, energy storage systems have received much attention. With the challenges posed by the rapid depletion of lithium resources and its uneven distribution, sodium-ion batteries (SIBs) with similar electrochemical properties have gradually become a research hotspot. Hard carbon (HC) materials have become one of the highly promising anode materials for SIBs due to their abundance of resources, cost-effectiveness and high carbon conversion. Coal-based hard carbon (CHC) has become one of the competitive materials in HC precursors due to its low cost and high carbon conversion. This article reviews recent research on the preparation strategies, optimization modifications, and electrochemical properties of coal-based hard carbon materials. Furthermore, we discuss the development prospects and research directions for coal-based hard carbon materials.

The high nickel cathode material LiNi _x Co _y Mn_1-x-y O₂(x≥0.6,NCM) is considered to be one of the most valuable cathode materials for lithium?ion batteries due to its low cost,high energy density and long service life.Although the high nickel content leads to a significant increase in the specific capacity and energy density of NCM,the increase in nickel content leads to poor cycling and thermal stability,which severely limits its practical application.Doping modification is an effective strategy to improve the structural stability and electrochemical performance of NCM.In this review,the common doping preparation methods of NCM are first described in detail.Subsequently,the effects of various doped elements on the lithium storage,rate performance and cycling performance of NCM were systematically analyzed.Finally,the development and future challenges of NCM are prospected,which is expected to provide an important reference for the application of NCM.

Nickel?iron (NiFe)?based transition metal catalysts have garnered significant attention in recent years for their excellent electrocatalytic performance,particularly in the oxygen evolution reaction (OER).However, the catalytic efficiency of NiFe?based transition metal catalysts still has a certain gap compared with precious metal Ru or Ir, so it is necessary to modify it.Research has shown that defect engineering can effectively enhance the OER catalytic activity of NiFe?based transition metal catalysts.The types of defects in NiFe?based transition metal catalysts, the characterization methods, and the methods for constructing defect materials are summarized, and an overview the research progress of the OER study of defect?type NiFe?based transition metal catalysts is given; the challenges of defect engineering to improve the OER performance are discussed and prospects for future development are proposed.

With the significant increase in the price of lithium?ion batteries,low-cost,energy-efficient sodium-ion batteries have attracted widespread attention.As a bridge connecting the positive and negative materials of sodium ion batteries,the electrolyte plays a crucial role.The first coulomb efficiency,cycle stability and rate performance of sodium?ion batteries can be effectively improved by constructing suitable electrolytic liquid system for different electrode materials.In this paper,the research progress of various electrolyte additives in sodium?ion battery systems,the formation mechanism of interface film and the future research direction of electrolyte additives have been discussed.

Sodium metal has the advantages of abundant sources,low cost and uniform distribution,so sodium-ion batteries are considered to be one of the most promising large-scale energy storage systems.The cathode material in sodium-ion batteriesis a critical factor affecting both the electrochemical performance and production cost of the battery.Layered transition metal oxides have attracted significant attention because of their high energy density,simple synthesis method and environmental friendliness. This paper provides a comprehensive summary and review of the research on layered cathode materials from the perspective of their composition structure,phase transition mechanism,charge compensation mechanism,and modification strategies,which reveal the key factors limiting the improvement of the electrochemical performance of layered cathode materials,analyzing the effective means to inhibit phase transition process and the rational design to enhance the reversibility of anion redox reaction.Furthermore, this paper offers an outlook on future development trend.

Sodium?ion batteries are considered a promising alternative to lithium?ion and lead?acid batteries, offering a balance between performance and cost?effectiveness for applications requiring moderate energy density and low cost. Hard carbon stands out as the most promising anode material for sodium?ion batteries, with the majority of scholars attributing its sodium storage capacity primarily to its porous structure. However, characterization techniques for this porous structure are currently very limited. This hinders in?depth analysis of the hard carbon pore structure and makes it more difficult to design performance enhancement strategies. This review provides an overview of current methods for characterizing the pore structure of hard carbon, including transmission electron microscopy, gas adsorption, X?ray small angle scattering, and helium true density testing. The combined use of these methods helps accurately characterize the pore structure of hard carbon and provides research ideas and technical support for the design of high?performance hard carbon anodes.

The use of solar photocatalytic degradation of pollutants is one of the most promising technologies to solve water pollution problems and achieve solar energy conversion. By changing the amount of g-C₃N₄ added, g-C₃N₄/Co₃O₄ catalysts with different g-C₃N₄ mass fractions are prepared based on the calcination method with cobalt nitrate hexahydrate (Co（NO₃)₂-6H₂O) and urea (NH₄CNO) as raw materials. The samples are analyzed and characterized using X-ray diffraction （XRD）, X-ray photoelectron spectroscopy （XPS） and ultraviolet visible absorption spectroscopy （UV-vis DRS）. To speculate on the active species of the catalyst, capture agent experiments are conducted on it. The results indicate that the synergistic effect between g-C₃N₄ and Co₃O₄ can improve the transfer and separation efficiency of charge carriers at the interface between the two phases. Under visible light, the degradation effect of 10% g-C₃N₄/Co₃O₄ is the best, with a degradation rate of 66.50%, which is higher than the degradation effect of single Co₃O₄ （degradation rate of 35.90%）. The active species of the catalyst are mainly superoxide radicals（·O₂-） and holes（h⁺）. After compounding with g-C₃N₄, the drawbacks of Co₃O₄ electron hole pair, such as too fast recombination and a deficient energy level structure, are improved, providing ideas for the degradation of organic pollutants in the future.

As the global energy system accelerates its transition toward renewable energy,electrochemical energy storage devices play an increasingly vital role in ensuring power supply stability and promoting efficient energy utilization.However,low-temperature environments pose a significant challenge to the performance of electrochemical energy storage devices.Especially for widely used lithium-ion batteries,the problems such as significant decrease of charge and discharge capacity,increase of internal resistance and shortening of cycle life are particularly prominent,which seriously limits the commercialization development of lithium-ion batteries in cold regions and other scenarios.To address this challenge,this paper provides a systematic review of current research progress on the performance of electrochemical energy storage devices in low-temperature environments.First of all,focusing on the core research topic of modification and optimization of battery cathode materials and electrolyte systems.This study systematically elucidates the mechanism contributing to battery performance under low-temperature conditions,including changes in material resistivity,reduced reactivity of active materials,and increased viscosity of electrolyte materials.Then,the modification strategies of electrolyte to improve the performance of batteries under low temperature are reviewed and analyzed.In addition,other effective ways to optimize the low-temperature performance of energy storage devices and their mechanisms for improving the electrochemical performance are also expounded.

With the development of industrialization and modernization, water pollution has become increasingly serious, and the use of sunlight for water pollution degradation has become a future development trend. In this paper, flower?like BiOI photocatalyst was prepared via a solution route at room temperature without any template, and characterized by X?ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and UV?Vis diffuse reflectance spectra (UV?Vis DRS). As?synthesized flower?like BiOI showed better visible light photocatalytic activity for degrading Rhodamine B (RhB) than TiO₂. The experimental results of active species and electron spin resonance (ESR) measurement showed that ·O {}_{\mathrm{2}}^{-} was the main active species in the photocatalytic degraded process of organic pollutant over flower?like BiOI, and the possible degradation mechanism was speculated. This study provides a simple and convenient synthesis method for high activity photocatalysts.

CO₂ geological storage is one of the most important means to mitigate the greenhouse effect.The safety of CO₂ securely stored in underground reservoirs largely depends on the mechanical integrity of the caprock.This paper establishes a coupled fluid-solid model for CO₂ geological storage to study the changes in pore pressure,vertical displacement,and effective stress in the caprock during the CO₂ injection process.It analyzes the effects of CO₂ injection rate,caprock elastic parameters,and geostress factors on the occurrence of tensile and shear failures in the caprock.The results indicate that,at the initial stage of CO₂ injection, changes in pore pressure,vertical displacement,and effective stress at the bottom of the cap near the injection well are significant but gradually stabilize thereafter.The area near the injection well is considered the most critical part of the caprock,where the risk of mechanical failure is greatest.During the CO₂ injection process,the injection rate and geostress factors have the most significant impact on the occurrence of mechanical failures in the caprock.The findings of this study provide a theoretical basis for assessing the long-term stability and safety of CO₂ geological storage systems.

Cellulose, due to its abundance and propensity to form spherical structures, serves as an exceptional precursor for the synthesis of high-performance hard carbon materials used in sodium-ion batteries. This study explores the interplay between different cellulose types, their structural evolution during hydrothermal spherization, and the subsequent impact on the microcrystalline characteristics and electrochemical performance of the resulting hard carbon for sodium storage. The results observed that the crystallinity of various cellulose precursors-namely natural cellulose, α-cellulose, and microcrystalline cellulose-and their corresponding hard carbons are positively correlated. Among these, hard carbon derived from α-cellulose demonstrated superior attributes, including the highest closed pore volume and a balanced defect density, which contribute to its enhanced sodium storage capacity. Furthermore, the hydrothermal treatment of α-cellulose at 220 °C was optimized to achieve a spherical morphology, which significantly benefited both the capacity and rate performance of the hard carbon. The reversible capacities at current densities of 20 and 2 000 mA/g are 329.4 and 53.9 mA·h/g, respectively.

As the core of heavy oil upgrading, fluid catalytic cracking(FCC) units have long been the main pillar of economic benefits for petrochemical enterprises in China.This paper reviews the development history of domestic FCC technology and summarizes the current status of FCC technology from three perspectives based on target products:Oil production technology,light olefin maximization technology,and product structure adjustment technology.It emphasizes summarizing the design concepts,main characteristics and commercial application of different FCC technologies,with a particular focus on comparing the differences in reactor types and catalyst.Additionally,research efforts aimed at improving oil quality to meet market demands,enhancing the yields of low?carbon olefins,BTX(benzene,toluene,xylene),and other basic chemical raw materials,as well as optimizing their selectivities,are discussed,providing viable technical solutions for high?quality enterprise development.Future research priorities for FCC technology include feedstock heavy and diversified processing,product quality improvement,flexible product structure adjustment,and cleaner production processes.

Nylon 66(PA66),as an important engineering plastic,features excellent mechanical properties,wear resistance and heat resistance,and is widely used in the automotive,electronic,mechanical and aerospace fields.However,its inherent high hygroscopicity,poor low-temperature toughness,insufficient processing fluidity and inadequate flame retardancy limit its application in some high-performance scenarios.In recent years,significant progress has been made in the modification research of PA66.Mainly through various means such as physical blending,chemical grafting, and copolymerization modification,its microstructure and macroscopic properties are regulated,thereby preparing composite materials with high strength,high toughness, low water absorption rate,excellent flame retardancy or thermal conductivity.This article introduces the research progress of various high-performance PA66 composites in recent years,analyzes the influence of various modification strategies on the structure and performance of the materials,and the preparation of various high-performance PA66 composites has expanded the application scope of PA66,which is more conducive to its development in high-performance and functional industries such as new energy and automobiles.

Sodium-ion capacitors represent a novel class of energy storage device that integrates the respective advantages of sodium-ion batteries and electric double-layer capacitors. Nevertheless, the mismatch between the positive and negative electrode kinetics of sodium ion capacitors can lead to their low power density and poor cycling stability. Since the advent of single-atom catalysis, single-atom metals have garnered substantial attention in energy storage research due to their high atomic efficiency, exceptional catalytic activity, superior selectivity, and remarkable stability.Firstly, the challenges faced by electrode materials for sodium ion capacitors were elaborated, and the energy storage mechanism of sodium ion capacitors was analyzed. Secondly, the characteristics of single atom catalysts and the preparation methods of carbon supported metal single atom materials were introduced. Then, the application progress of metal monatomic materials in sodium ion capacitors was summarized. Finally, the application prospects of metal single atoms in sodium ion capacitors were discussed.

During the process of water electrolysis,the "bubble effect" will significantly reduce the overall performance of the system.The classical nucleation theory (CNT model） fails to reveal the regulatory mechanism of the electrical double layer (EDL),surface microstructure,and mass transfer synergy on nucleation kinetics in actual electrochemical systems.This study develops an electrode interface bubble nucleation model with the synergistic effect of electrical double layer?mass transfer?surface microstructure,considering the synergistic regulation mechanism of ion migration diffusion behavior,electrode surface nano microstructure,and concentration boundary layer on the nucleation process.The research results show that the synergistic effect of EDL and microporous structurel generates significant potential gradients at the surface micropores,leading to an increase in local supersaturation and prioritizing bubble nucleation.At high overpotentials,the effect of the concentration boundary layer on nucleation energy barrier exhibits a nonlinear relationship.The thinner the concentration boundary layer is,the more significant the decreasing trend of the nucleation rate at high potential will be.The growth of bubbles is dominated by the net concentration flux near the three?phase contact line (TPCL),exhibiting a two?stage growth characteristic.The study provides a theoretical basis for optimizing the surface design of gas evolution electrodes.

With the acceleration of industrialization,a large amount of refractory organic contaminants were discharged into water, bringing new challenges to the traditional water treatment technologies.As an advanced oxidation process (AOPs),the heterogeneous catalytic ozonation shows great potential for water treatment due to its high efficiency and environmental friendliness.The surface hydroxyl groups,Lewis acid sites,redox cycling, and structural defects could act as active sites on heterogeneous catalysts,which could effectively promote the ozonolysis reaction and generate reactive oxygen species (ROS) for enhancing the degradation of organic pollutants.By active site engineering,both the metal?based catalysts and non?metal catalysts could significantly improve the efficiency of ozonation reactions.This paper provides a comprehensive review of the use of heterogeneous catalytic ozonation in industrial wastewater treatment.The working mechanism of this technology,the active sites of catalysts,the typical catalysts and their applications in wastewater treatment were fundamentally discussed.Finally,this paper provides insights into the future research direction of heterogeneous catalytic ozonation,emphasizing the importance of establishing a unified catalyst evaluation standard and improving the catalyst stability for the practical application of the heterogeneous ozonation catalysts.

As the demand for energy storage escalates, sodium?ion batteries （SIBs） are increasingly in the spotlight due to their low cost and the plentiful availability of sodium resources. Particularly, hard carbon anode materials have emerged as a focal point of research, attributed to their superior cyclic stability and elevated energy density. This review delves into the advancements in hard carbon anode materials for SIBs, encompassing the screening and design of HCs precursors, surface modifications, pore structure adjustments, carbonization induction, heteroatom doping strategies, and additional tactics to augment the performance of HCs. By thoroughly examining the influence of HCs's pore structure, surface functional groups, and microstructure on the sodium storage mechanism, the review explores the potential for optimizing HCs performance through various fabrication processes. Furthermore, the article addresses the interfacial reaction mechanisms between HCs and electrolytes, along with possible avenues for enhancing HCs's cycling and rate capabilities through interface engineering. Ultimately, the review anticipates the future trajectory of HCs technology, including the design of nanostructures, surface modifications, and green manufacturing processes, underscoring the pressing need for the development of high?performance, cost?effective, and environmentally benign SIBs.

The study of the environmental hazards of chemical gas pipeline rupture is of great significance to the design of explosion prevention measures and the development of emergency response programs. Taking a typical overhead gas pipeline as the research object, the environmental hazards of the whole process of natural gas leakage diffusion, jet fire, vapor cloud flash fire and explosion accident development were analyzed. The results show that when designing explosion-proof measures and formulating emergency plans, the explosion risk area should be calculated according to the low wind speed. Natural gas leakage mainly affects the chemical park B area, office buildings A， B， C, street stores A. The downwind direction of the occurrence of jet fire accident 8.7~76.1 m is a high-risk area, affecting the area of the chemical park B area, office buildings B and the street stores A. The area affected by the vapor cloud flash fire is Chemical Park B, Chemical Park A, Office Buildings A, B, C, D, Street Shops A, Residential Area A, the main road and the edge of the Science and Technology Park, so the area should be evacuated in advance of the fire. Natural gas explosion damage area is downwind -47.1~67.2 m, mainly affecting the chemical park B, chemical park A, office buildings B, street stores A, residential neighborhoods A.

For the reaction of catalytic dehydrogenation of ethanol to produce acetaldehyde, current catalysts face the challenge of limited selectivity, particularly exhibiting poor performance in the efficient generation of acetaldehyde. Some catalysts are hindered in the dehydrogenation process due to excessive acidity, which urgently needs to be addressed. Therefore, the development of novel catalysts with high?performance surface basicity is crucial.Two composite catalysts, La₂O₂CO₃/ZnO?a and La₂O₂CO₃/ZnO?b, were prepared using the co?precipitation method and the solution combustion method. The performance of the catalysts was evaluated by varying preparation conditions such as precipitation pH, aging time, calcination temperature, and calcination time to determine the optimal synthesis parameters. Advanced characterization techniques, including Scanning Electron Microscopy, Transmission Electron Microscopy, X?ray Diffraction, and CO₂ Temperature?Programmed Desorption, were employed to thoroughly investigate the catalyst's crystal phase, morphology, surface basicity, and their relationship with catalytic performance. The optimal process conditions for ethanol dehydrogenation to acetaldehyde were investigated on the best?performing catalyst. When the precipitation pH was 9.0, the aging time was 12.0 h, the ratio of n_La to n_Zn was 1.0, and the calcination temperature was 600 ℃, the optimal preparation conditions for the solution calcination method were determined as follows: calcination time of 5.0 h, calcination temperature of 550 ℃, and n_La/n_Zn of 1.0. Under the conditions of a volume space velocity of 1.0 h?1, a reaction pressure of 1.0 MPa, and a reaction temperature of 190 ℃, La?O?CO?/ZnO?a achieved the highest acetaldehyde yield of 57.60%.

Blending poly(propylene carbonate) (PPC) with poly(adipate?butylene terephthalate) (PBAT) was involved in the preparation of PPC/PBAT composites. However, the limited compatibility between the two materials hinders the potential performance enhancement of PPC/PBAT composites. To improve the compatibility between PPC and PBAT, maleic anhydride (MA) as a polar monomer and 2,5-dimethyl-2,5-bis(tert-butyl peroxy) hexane (DHBP) as an initiator were chosen for grafting onto PBAT to produce copolymer grafted Maleic anhydride (PBAT-g-MA).The interplay between PPC and PBAT-g-MA, as well as its impact on the properties of the blend, was thoroughly examined. The elongation at break of the blend was found to gradually increase with higher mass fraction of PBAT-g-MA. The elongation at break of PPC/PBAT-g-MA blends increased from 21.2% to 68.1%（60 and 40 are the quality scores of PPC and PBAT-g-MA, respectively）. Studies have shown that when the PBAT-g-MA content is lower than that of PPC, PBAT-g-MA functions as a uniformly dispersed phase within the PPC matrix. The anhydride group present in the material can effectively react with the end groups of PPC, thereby significantly enhancing compatibility between both phases and promoting stress transfer at interface layers to improve the mechanical properties of blends.

Sodium-ion batteries (SIBs) have garnered considerable attention as a viable option for large-scale energy storage,with O3-type layered transition metal oxides identified as one of the most promising cathode materials due to their superior specific capacity.However,the stability of these materials at elevated voltages remains a critical challenge,hindering their broader application.In this study,O3-NaNi_1/3Fe_1/3Mn_1/3O₂ was systematically characterized using scanning electron microscopy(SEM), transmission electron microscopy(TEM),and in-situ X-ray diffraction(XRD) to elucidate the relationship between microstructural evolution and electrochemical stability.The results reveal that phase transitions significantly impair Na? diffusion kinetics. Notably, the irreversible P3-O3' phase transition at high voltages above 4.1 V results in a reduction of the Na⁺ diffusion coefficient by at least five orders of magnitude,which is reflected by a substantial increase in internal resistance.Moreover,the O3' phase emerging during discharge triggers the formation of the P'3 phase,deviating it from the electrochemical pathway established during charging and thereby severely compromising the material’s cycling stability.

Transition metal sulfides are known for their high conductivity and theoretical lithium storage capacity,making them promising materials for phase change lithium storage.However,their cycling stability needs improvement.A simple electrostatic spinning method was used to prepare composites with in situ growth of cobalt-based zeolite imidazolite backbones(Co-ZIFs) on electrostatically spun fibers,and the stabilized structure of microzonated ZIFs was exploited to achieve spatially confined domains of metal particles in an N_? heat treatment. Cobalt sulfide/carbon fiber composites (CoS/CFs) were then synthesized through a sulfidation reaction.X-ray diffraction (XRD) and Raman spectroscopy confirmed the uniform distribution of CoS particles on the carbon nanofibers.The optimized composite showed excellent lithium storage performance,maintaining a specific capacity of 584.5 mA·h/g after 250 cycles at a current density of 1 A/g.This demonstrates outstanding cycling stability and suggests promising applications in lithium storage.

According to the requirements of constructing a fair and open large?scale platform by the National Pipeline Network Group,the surplus transportation capacity of crude oil pipelines will be opened to the whole society.This article investigates the changes in energy consumption costs in the batch transportation of blended crude oil in pipelines using a simulation and modeling approach.Based on the simulation results,an optimization model for the batch transportation of blended crude oil in the pipeline system is established.The relationship between energy consumption costs and viscosity,as well as throughput index variations,is analyzed.This optimization model enables the cost?effective batch transportation of blended crude oil with different viscosities, thereby providing technical support for the safe and economically efficient transporting of new crude oil with different properties in the pipeline.

In order to resolve the limitation of the built-in catalyst database in Aspen simulations,a dual-rate kinetic model based on the Power Law (PL) formulation is proposed.The kinetic model is integrated into Aspen Plus for multi-process simulation of hydrogen production.By incorporating the influence of catalysts on the reactions during the simulation,a more realistic chemical process simulation is achieved.The dual-rate kinetic model accurately reflects actual hydrogen production conditions: increasing temperature and reducing liquid hourly space velocity (LHSV) both enhance methanol conversion and simultaneously increase CO selectivity.The steam-to-carbon molar ratio has a minor impact on the reaction.By considering energy consumption,the optimal range of the steam-to-carbon molar ratio is 1.0~1.4.Under the condition in which the reaction temperature is 280 °C and the feed flow rate is 1.5 mL/min,the multi-process simulation results demonstrate that the CO concentration in the product is reduced to only 6.89 μL/L after methanol steam reforming, water-vapor shift,and CO selective oxidation.This CO concentration meets the requirements for proton exchange membrane fuel cells(PEMFC).

The long-distance natural gas pipeline is characterized by large diameter and fast flow,and the uneven mixing of hydrogen gas will increase the risks of metal hydrogen embrittlement,seal leakage and unstable operation of equipment in the pipeline transportation system.According to the operating conditions of a long?distance natural gas pipeline in China,numerical simulation was used to study the flow field characteristics and mixing effect of four types of static mixers (SK,SX,SL,HEV) when hydrogen doping is transported(the ratio of hydrogen doping is 3%).The results show that all four types of static mixers have disturbing mixing effects on natural gas with hydrogen addition,and the value of the mixed non?uniformity COV decreases with the increase of flow rate,while the pressure loss increases with the increase of flow rate.The mixing characteristics and effects of SK, SX,SL and HEV type mixers vary significantly under the operating conditions of 3% hydrogen doping ratio,4.22 MPa hydrogen doping pressure,and flow rates ranging from 13×10⁸ Nm³/a to 36×10⁸ Nm³/a.The COV value should be reduced to less than 5% at different mixing distances.It can be optimally or innovatively designed with a relatively simple structure, short mixing distance, low non?uniformity, excellent turbulence characteristics,good shear characteristics, and moderate pressure drop as a large-caliber long-distance natural gas main pipeline hydrogen mixer.

To address the challenge of wellbore blockage during the development of a certain oilfield, Y3 crude oil was taken as the research object. Laboratory experiments were conducted to analyze the composition of the crude oil and the main components of wellbore blockage materials.Toluene extraction was performed on formation blockage materials collected from the oilfield, and XRD was used to analyze the composition of toluene?insoluble substances. The soluble fraction was separated into four components, with a focus on studying the composition and properties of asphaltenes in the soluble fraction and Y3 oil samples. Through asphaltene adsorption experiments, oil?water interfacial tension, underwater contact angle, etc., were measured to explore the effects of asphaltene polarity and aromaticity on interfacial properties. The experimental results show that the main minerals of the formation blockage of the wellbore are quartz, feldspar, calcite, etc. Compared with the asphaltene in Y3 crude oil, the asphaltene in the blockage has higher molecular weight, heteroatomic mass fraction and aryl carbon ratiowith minimal wax content in blockage materials. The main cause of wellbore blockage was the adsorption of asphaltenes on sandstone. The heteroatom mass fraction and polarity of asphaltenes had significant effects on adsorption capacity and interfacial tension.

The dual?carbon strategy highlights the urgent need to develop efficient photocatalytic hydrogen production technologies. Graphitic carbon nitride (g?C?N?) has attracted wide attention due to its low cost and excellent stability, but it suffers from insufficient visible light absorption and rapid carrier recombination, which severely restricts its hydrogen production performance. To overcome these issues, we successfully prepared boron-doped g?C₃N₄ （BCN） using a H₃BO₃?assisted segmented temperature?controlled calcination strategy, with boric acid as the boron source precursor. The effects of boron doping on the band structure and photoelectric properties of g?C₃N₄ were systematically investigated through various photoelectric characterization techniques. The results demonstrate that an appropriate level of boron doping effectively modulates the electronic structure of g-C₃N₄, enhancing its visible light absorption and improving the separation efficiency of photogenerated carriers. Specifically, the BCN?2∶5 sample (with a mass ratio of H?BO? to g?C?N? of 2∶5) achieves a hydrogen evolution rate of up to 1 507 μmol/(g·h) under visible light irradiation. This study offers valuable insights and guidance for the design of highly efficient doped g?C₃N₄ photocatalysts.

In order to quickly define the dangerous distance of leakage in hydrogen?blended natural gas high?pressure pipelines, this study established a mathematical model of small hole jet leakage of hydrogen?blended natural gas high?pressure pipelines in open space by integrating the pipeline leakage model,nominal nozzle model and jet in cross?flow integration model,verified the applicability of the jet in cross?flow integration model under high?speed jet and analyzed the influence of hydrogen ratio,wind speed leakage hole diameter and pipeline pressure on the leakage jet trajectory and the influence of hydrogen ratio,wind speed and nominal diameter on the maximum explosion danger distance.The results shows that the JICF model is in good agreement with the experimental data and the numerical simulation data.The greater the hydrogen mixing ratio,the diameter of the leakage hole and the pipeline pressure are,the less the deflection degree of the leakage jet trajectory will be.The higher the wind speed is,the greater the deflection degree of the leakage jet will be.The relationship between the hydrogen ratio and the maximum dangerous explosion distance decreases linearly when the hydrogen ratio is lower than 44.4%,and increases linearly when the hydrogen ratio is higher than 44.4%.The relationship between the wind speed and the maximum dangerous explosion distance is approximately linear.The nominal diameter is directly proportional to the maximum explosive danger distance.

The authors used a bifunctional reducing agent containing degradable groups and oxidized metal ions as a redox agent to initiate free radical polymerization and synthesize a polymer damper to build degradable groups on the vinyl polymer backbone. The results showed that the azo groups were degradable under high temperature and also had high hydrolytic stability. The degradation behavior of polymeric drag reducers containing temperature-sensitive azo groups was characterized by gel permeation chromatography (GPC), which demonstrated that the polymer backbone contained multiple unstable bonds. It was also found that the drag reducers with azo bonds on the polymer main chain had as good drag reducer properties as the pure drag reducers. However, those with azo bonds in the main chain will lose their damping performance once subjected to high temperatures. This study provides a reference for the selection of low-injury multifunctional slickwater fracturing fluid systems suitable for shale gas reservoirs.

Aqueous zinc?ion batteries demonstrate broad application prospects due to their high safety,low cost,excellent electrochemical performance,and other characteristics.This review systematically summarizes structural regulation strategies for flexible electrolytes tailored for aqueous zinc?ion batteries.It focuses on the construction methods,ion conduction mechanisms,and mechanical reinforcement approaches of hydrogel and polymer electrolytes.In addition,it analyzes the key challenges related to electrochemical stability,interfacial compatibility, and environmental adaptability.This work aims to advance the development of flexible electrolytes for enhancing the electrochemical performance of aqueous zinc?ion batteries and provide theoretical guidance and research references for the design and functional realization of flexible electrolyte materials.

To address the issues of low theoretical specific capacity, poor fast?charging performance, and insufficient safety in commercial graphite anode materials, a new type of self?supporting composite electrode was constructed, which achieved an improvement in the comprehensive electrochemical performance of lithium?ion batteries. Using carbon cloth (CC) as a flexible substrate, a Co₃O₄/ZnO heterojunction structure was grown in situ on its surface via the hydrothermal method, followed by heat treatment, successfully preparing a self?supporting Co₃O₄@ZnO//CC anode material. Microstructural and compositional analyses were conducted using characterization techniques such as XRD, SEM, TEM, and XPS, while electrochemical tests were employed to evaluate its lithium storage performance. Results demonstrated that the three?dimensional porous nanosheet array of Co₃O₄@ZnO effectively mitigates volume changes and facilitates electron transport. The Co₃O₄@ZnO//CC electrode exhibited an initial discharge and charge specific capacity of 3.96 and 3.28 mA?h/cm2 at 2.00 mA/cm2 current density, respectively, with a coulombic efficiency of 82.83% in the first cycle and a capacity retention rate of 56.40% after 100 cycles. Both its cycling stability and rate performance outperformed those of Co₃O₄//CC and ZnO//CC electrodes.

Electrocatalytic hydrogen evolution technology plays a pivotal role in promoting sustainable energy conversion and storage,which is essential for achieving carbon neutrality and enhancing the efficient utilization of renewable energy.However, current electrocatalysts still face significant challenges in terms of activity,stability,and cost,which hinder their large-scale application.Alloy catalysts,with their tunable compositions and structures as well as unique electronic properties,have demonstrated great potential in improving catalytic performance.This review provides a comprehensive overview of the performance modulation mechanisms and strategies of alloy catalysts in hydrogen evolution reactions.Specifically,it focuses on three key aspects:Composition design,crystal structure regulation,and hybridization with other functional materials,highlighting their recent advances in the electrocatalytic hydrogen evolution reaction.Representative studies are discussed to elucidate the synergistic effects among multiple metal components in alloy systems and their impact on catalytic performance.Finally,current challenges in rational alloy catalyst design are summarized,and future research directions are proposed,aiming to provide theoretical guidance and technical insights for the development of efficient and cost-effective electrocatalytic materials.

In the face of the increasingly serious energy crisis and environmental pollution,it is important to develop durable and efficient photocatalytic materials for hydrogen production from water splitting.The MXene@TiO₂ of high-performance MXene-based photocatalytic materials (M@T) is synthesized by a one-step hydrothermal method at 160 ℃ using Ti₃C₂ as the titanium source and TiO₂@Ti₃C₂ derivatives synthesized by a one-step hydrothermal method.Co-MoS_2-x O _y (C-M) is prepared by sodium molybdate dihydrate (Na₂MoO₄·2H₂O) as molybdenum source,CH₃CSNH₂ as sulfur source,and cobalt nitrate hexahydrate (Co(NO₃)₂?6H₂O) as cobalt source.M@T/C-M composites are prepared at the ratios of m(M@T)/m(C-M) of 1∶1,1∶2,1∶3 and 1∶4.The structure and surface morphology of different composite systems are characterized by XRD,SEM,XPS,UV-vis,etc.At the same time,the photocatalytic degradation of methylene blue (MB),an organic pollutant in water,is tested by using xenon lamp as the light source.The results show that the M@T/C-M composites are successfully synthesized,and the light absorption range is increased to the visible region.The degradation rate of M@T/C-M(1∶3) in 20 mg/L MB solution is as high as 92.6%.The photodegradation of MB by M@T/C-M photocatalyst is mainly driven by ?OH and ?O {}_{\mathrm{2}}^{-} radicals.

Based on density-functional theory (DFT) and wave function analysis procedures, the optical and molecular absorption properties of two structurally different pentacyclooxonium salt molecules have been investigated, and the physical mechanism of the formation of a built-in electric field due to orbital polarization caused by structural distortions, which induces charge transfer and leads to a nonlinear optical spectrum, has been explored.The properties result from the orbital polarization-induced built-in electric field driving charge transfer due to structural distortion. Theoretical analysis of ultraviolet-visible absorption spectroscopy (UV-vis) spectra is first performed to investigate the optical properties. The electronic excitation characteristics of the built-in electric field-driven charge transfer in molecules are analyzed in detail by transition density matrix (TDM) and charge differential density (CDD). Combining transition electric dipole moment density (TEDM) and transition magnetic dipole moment density (TMDM) analysis, the physical mechanism of the structure-induced chirality in their electronic circular dichroism (ECD) spectra is revealed. The results can provide theoretical references for the preparation of novel chiral materials as well as the research and development of optoelectronic materials and their practical applications.

The filtration and separation area of a station on the China?Russia East Route is set as parallel pipelines,and the uneven distribution of branch flow may occur due to the differences in internal pressure and pipeline layout,which affects the filtration efficiency and the overall work efficiency.In order to avoid pipeline bias, the flow direction of the filtration and separation area is studied based on computational fluid dynamics (CFD).Results show that pressure distribution, turbulent flow distribution, frictional resistance loss along the system,fluid inertia and other factors affect the branch pipe flow distribution.Among 11 parallel pipeline configurations,the axial inlet and radial outlet configuration (Type 3) with inlets and outlets on the same side exhibits the least flow maldistribution overall.Under normal working conditions,flow maldistribution decreases with increasing manifold diameter and branch pipe spacing within the calculation range.Fault conditions,such as branch pipe blockages,significantly exacerbate flow maldistribution in the system.It is concluded that the flow distribution rule and the main factors affecting the flow distribution are obtained,which is helpful to guide the design and construction of gas transmission station.

To address the issue of high steam consumption in the propane removal tower of the three tower gas fractionation process in refineries, it is proposed to use a high and low pressure dual tower propane removal process instead of the single tower propane removal process in the original process. The process was simulated under steady?state conditions using Unisim Design process simulation software. The steam load of the high?pressure depropanizer and the hot water load of the deethanizer were analyzed, and the main operating parameters were optimized. The results showed that under the operating conditions of n(top C₃ production)/n(total feed C₃)=0.6, top pressure of 1.81 MPa, feed tray position of the 10th plate, and feed positions of the 114th and 126th plates at the top of the propane removal tower and low?pressure propane removal tower respectively, using the high and low?pressure double tower propane removal process can save 56.12% of steam load compared to the original process, save 49.83% of hot water load in the ethane removal tower compared to before optimization, reduce total energy consumption by 235.4 kW, and save about 339.71 yuan in thermal utility costs per hour.

In the process of crude oil gathering and transportation,the use of gas or electric energy at the wellhead for its heating and viscosity reduction is prone to cause a large amount of energy consumption and environmental pollution.Solar photovoltaic technology is an efficient and clean new energy technology coupling this technology with thermal storage technology can circumvent the shortcomings of solar energy instability,meet the needs of crude oil viscosity reduction and fixed heating,reduce the consumption of electric energy,and contribute to the carbon peak and carbon neutrality goal.A wellhead crude oil heating system based on thermal energy storage device (TES) and flat-plate solar collector (FPC) is studied,and FPC and crude oil heater in the system are designed and selected.Taking Shengli oilfield as the application scenario of the system,we analyzed and calculated the solar irradiation resources and the heating demand of crude oil at the wellheads in the winter half year (October to March),and reasonably configured the FPC with a heat collection area of 152 m² and the 17~20 m³ hot and cold water tanks,and gave the operation scheme of the system under different irradiation amounts.The results show that the system can warm up the oilfield wellhead extractive fluid by 25 ℃,work continuously for 24 h per day,reduce carbon dioxide emission by 54.25 t in winter and half a year,and save operation cost by 53 000 yuan,which has good energy-saving and emission reduction benefits and economic benefits.

Sodium?ion batteries are gradually becoming a powerful alternative to lithium?ion batteries in the low?speed two?wheeled electric vehicle market and large?scale energy storage applications due to their excellent low?temperature performance, significant cost?effectiveness,and high safety features.The potential of hard carbon with improved performance to substitute graphite in the sodium ion battery anode has attracted widespread attention.However,the high energy consumption and expensive cost still need to be overcome for commercialization of hard carbon anode.The key to developing anode materials for sodium?ion batteries that combine low cost,high sodium ion storage capacity,and excellent cycling stability will help to extend the application of hard carbon anodes in sodium?ion batteries.Biomass has become an attractive raw material for the preparation of hard carbon due to its renewable,low?cost,and environmentally friendly characteristics.It has been shown that the sodium storage properties of biomass?derived hard carbon are affected by multiple factors such as carbonization temperature,precursor variety,and microstructure.Hence,this review summarizes the relevant models proposed for the sodium storage mechanism in terms of the sodium storage behavior of hard carbon.The preparation of hard carbon anode materials,including the effect of electrochemical optimization procedures such as pyrolysis,activation, and doping is discussed.A further analysis of the sodium storage mechanism offers guidance for addressing the current issues such as the selection of precursors,the low initial Coulombic efficiency,and the limited means of closed pore regulation.

To address the corrosion failure issues in hydrogenation reaction effluent air cooler (REAC)systems, a typical process simulation model was constructed using the reverse order deduction method. This study investigated the influence mechanisms of different oil flow rates on the distribution of corrosive components within the system, ammonium salt crystallization temperature, and erosion risks. The results indicate that variations in oil flow rate do not significantly affect the aqueous distribution of corrosive components or increase the system's erosion risk. Additionally, the oil flow rate has minimal impact on the crystallization temperature of ammonium salts, meaning higher flow rates do not elevate the risk of salt formation. However, increasing the flow rate of vacuum gas oil (VGO) markedly reduces the corrosion factor (K), thereby lowering the overall corrosion risk. The VGO flow rate also has a pronounced influence on the aqueous NH?HS concentration at the air cooler outlet, whereas the effect of naphtha flow rate differs from that of diesel and VGO. Notably, raising the flow rates of diesel and naphtha increases the system pH, while increasing VGO flow rate decreases it. To mitigate corrosion risks, it is recommended to moderately increase the VGO content during crude oil processing while simultaneously boosting either the diesel content or injection water volume.

Leakage of refined oil pipeline can cause environmental pollution and threaten the safety of residents' lives and properties, making leakage monitoring and identification critical. This study establishes a leakage monitoring and identification model for undulating buried pipelines, generates pressure waves by controlling valve openings, and monitors and identifies leakage locations. The effects of valve opening and valve opening/closing interval time on leakage localization accuracy were analyzed. Results show that the model exhibits high accuracy for identifying medium?sized hole leaks but lower prediction capabilities for small and large holes, resulting in larger relative errors in leakage localization. When the valve opening decreases from 90% to 10%, 30%, and 50%, the amplitude of pressure wave signals decreases, and the relative error in leakage localization calculated by the model gradually increases. A valve opening of 10% is recommended. As the valve opening/closing interval time increases, the relative error in leakage localization grows due to interactions between pressure wave signals and reflected signals, with an optimal interval time of 1 second recommended.

An oil⁃soluble molybdenum sulfide catalyst (MS⁃1) was prepared by a ‘one⁃pot’ synthesis method and characterized using XRD,FT⁃IR,XPS,and HR⁃TEM.The hydrodeoxygenation (HDO) performance toward methyl oleate and the hydrotreating capability for waste oils (with phosphorus,chlorine,and total metal contents of 18.14,138.80,and 173.60 µg/g,respectively) were evaluated in a high⁃pressure reactor.The results indicate that two⁃dimensional monolayer MoS2 active species were generated in situ during reaction,and the synthesized catalyst exhibited excellent overall performance.Under the conditions of a catalyst dosage of 380 µg/g,a reaction temperature of 360 °C,an initial H2 pressure of 4.0 MPa,and a reaction time of 3.0 h,the deoxygenation rates of methyl oleate and waste cooking oil reached 99.2% and 99.7%,respectively.The acid value and bromine value of the waste oil were significantly reduced from 173.60 mgKOH/g and 117.70 gBr/(100 g) to 5.28 mgKOH/g and 5.65 gBr/(100 g).The removal efficiencies of phosphorus,chlorine, and total metals were 92.17%,93.87%,and 96.92%,respectively.

With the development of large-scale storage tanks,structural safety issues such as foundation settlement and structural deformation that affect the operation of large storage tanks have increasingly become the focus of equipment management and inspection personnel.Research on foundation settlement detection and structural integrity evaluation of large storage tanks is of practical significance for ensuring the safe operation.This article analyzes the types and typical damage forms of tank foundation settlement,and proposes requirements for tank foundation settlement detection based on the characteristics of different tank service stages such as design,construction,and regular inspection.It clarifies the detection and evaluation methods for different types of settlement,and focuses on the research of graded evaluation methods for uneven settlement around the tank.A 4-level evaluation method for basic uneven settlement,including settlement difference evaluation,deviation from the plane settlement amplitude evaluation,local non-uniform plane settlement evaluation,and stress analysis evaluation,is proposed to effectively support equipment management and inspection personnel in conducting structural suitability evaluation under tank foundation settlement conditions.

Improper models of phase behavior are a major cause of many production problems faced by shale gas reservoirs. The phase behavior of oil?gas in micro?nano pores is crucial for shale oil and gas development. Considering the effects of capillary pressure and critical point shift on the thermodynamic phase equilibrium in micro?nano pores, a vapor?liquid equilibrium (VLE) model in the confined micro?nano pores was developed by using a volume?translated Peng?Robinson Equation of State(PR?EOS), and the relative error of prediction was less than 1.53%. Based on the improved VLE model, the phase behavior of hydrocarbon mixtures such as Bakken shale oil in the confined space was investigated. Results indicate that the nanopore confinement decreases the vapor?liquid density difference and equilibrium coefficient(K) of the light components and shrinks the phase envelope. As the pore size decreases, the interfacial tension (IFT) first decreases slowly and then drops sharply, particularly when the pore radius is less than 20 nm.This study can provide an important theoretical foundation to support the development of unconventional oil?gas resources.

Betaine surfactants have been widely used as oil displacement agents for tertiary oil recovery due to their unique amphiphilic structure,high surface activity,low critical micelle concentration and good emulsification performance.To investigate the effect of alkyl carbon chain number on the chemical flooding performance of betaine surfactants,5 kinds of betaine solutions with alkyl carbon chain number (n) of 12,14,16,18 and 20 were selected,and their interfacial tension and emulsification properties were tested.The parameters of radial distribution,density distribution,mean azimuth shift,rotation radius and binding energy were analyzed by using MS software，and conducted indoor simulated oil displacement experiments.The results show that with the increase of the number of carbon atoms of long alkyl chain,the oil displacement performance of surfactants was first enhanced and then weakened,and the chemical displacement performance of C₁₆HBC surfactants in betaine was the best.The effects of betaine solution with different alkyl carbon chain number on its energy,radial distribution,density distribution, mean orientation shift, binding energy and other parameters were determined by molecular simulation studies.Simulation oil displacement experiments verified that C₁₆HBC surfactant could significantly improve oil recovery by 20.7%.

The selectivity and stability of Pt?based catalysts can be improved by adjusting the active phase by adding additives. The active phase of Pt?based catalyst was regulated by changing n(Ga)/n(Pt) with Ga as an additive and characterized by BET, FT-IR, TG, H₂-TPR, etc. The n(Ga)/n(Pt) of the active phase was optimized under the reaction temperature of 580 ℃, volume space velocity of 2 000 h^-1 and hydrogen?hydrocarbon ratio (volume ratio of hydrogen to propane) of 1. The results show that the Pt in the Pt7Ga/Al₂O₃ catalyst has the smallest particle size and the best dispersion.The Pt7Ga/Al₂O₃ catalyst has the best dehydrogenation performance, and the propylene selectivity of the reaction for 3 h was 90.98%, which was 3.01% higher than that with the PtSn/Al₂O₃ catalyst. The regulation of Ga can enhance the interaction force between Pt and Al₂O₃ support, lower the acidity of catalyst and the degree of graphitization of catalyst carbon deposition.

During the development of the Fuyu oil reservoir in the Longxi block of Daqing,hydrogen sulfide (H₂S) was discovered and exceeded the threshold value (15.0 mg/m³), but its generation mechanism is still unclear. To investigate this, the mechanism of H?S generation in the Longxi block formation was investigated through laboratory experiments on H?S generation,combined with numerical simulations using PHREEQC and CMG software.The results show that the mechanism of H₂S generation in high?temperature reservoirs (100~125 ℃) is sulfate thermochemical reduction reaction, with viscosity of H₂S generated ranges from 3.20 mg/m³ to 6.10 mg/m³.In low?temperature reservoirs (≤60 ℃),the mechanism of H₂S generation is sulfate?reducing bacteria reduction reaction,with a maximum H₂S viscosity of up to 29.70 mg/m3.Fracturing fluid reduces the temperature in the near?wellbore zone, promoting SRB proliferation, and the viscosity of H₂S generated in a short time increases by 7.5 times compared to the sulfate?reducing bacteria reduction reaction in produced water. The mass concentrations of H₂S generated by the reaction of 1 m³ acid with the core and plug containing 0.80 mol FeS are 3 330.69 mg/m³ and 11 466.75 mg/m³,respectively. Therefore, fracturing and acidification are the main mechanisms for the generation of H₂S during the development of the Fuyu oil reservoir in the Longxi block.

Under solvothermal conditions,Cu（CF₃COO）₂·xH₂O was used as a soluble copper salt, and thiophene?2,5?dicarboxylic acid （H₂tdc） as a linear ligand, which reacted with 1,10?phenanthroline （phen） and 2,2′?bipyridine （bipy） respectively,to synthesize two one?dimensional chain compounds:[Cu（tdc）（phen）] _n （1） and [Cu（tdc）（bipy）] _n ·DMF （2）.The structures of the synthesized compounds were characterized by single?crystal X?ray diffraction（SC?XRD）.The compositions of the compounds were analyzed by polycrystalline X?ray diffraction and Fourier infrared spectroscopy.The performances of the compounds were studied through photocurrent response tests and solution stability tests.The results show that the asymmetric structural unit of compound 1 is extremely similar to that of compound 2,with both containing the same [Cu(tdc)] structural unit. Both compounds exhibit photochemical stability,but they show different photocurrent response values,which is attributed to the different surface?modifying ligands (phen and bipy) in the two compounds.

To address the lack of specialized thermal?hydraulic calculation models for temperature?resistant polyethylene pipelines in oilfield gathering and transportation systems,this study conducted quantitative analysis on their hydraulic friction characteristics and thermal temperature drop patterns during oil transportation through field experiments.Based on multi?parameter experimental datasets,systematic investigations were performed to reveal the influence mechanisms of key variables including fluid properties, transportation temperature,rate of water content,and flow rate on pipeline pressure drop and temperature decline.For the first time,a calculation framework for the overall heat transfer coefficient applicable to temperature?resistant polyethylene (TRPE ) materials was established.Simulation model libraries were constructed using PIPEPHASE software,followed by comparative analysis of deviations between theoretical predictions and field measurements under varying boundary conditions.Through this process, friction calculation models and heat conduction models tailored for TRPE materials were selected and optimized,which provide valuable theoretical support for the process design and safety evaluation of TRPE pipelines in engineering applications.

Aiming at the problems of conventional temporary plugging materials in horizontal shale gas wells in Sichuan, such as insignificant increase in temporary plugging pressure, easy shedding under low pressure difference and poor plugging effect, long‑acting and short‑acting temporary plugging knots for perforation plugging were prepared. Their degradation performance and pressure‑bearing plugging performance were evaluated, the influence of injection method on plugging efficiency was explored, and a temporary plugging knot injection device was developed, thus forming a knot‑based temporary plugging fracturing technology for shale gas. The results show that in polymer slick‑water fracturing fluid at 90 ℃, the degradation rate of long‑acting temporary plugging knots is less than 10% within 83 h and more than 99% after 174 h, while that of short‑acting temporary plugging knots is less than 10% within 5 h and more than 99% after 24 h. Both types of temporary plugging knots exhibit static pressure‑bearing capacity higher than 50.0 MPa and dynamic plugging efficiency above 90%. The maximum single injection capacity of the device is 60 temporary plugging knots with a size of 18~20 mm, and the injection rate is adjustable from 1 to 60 knots per minute. Field tests were carried out in Well Ning‑A, a horizontal shale gas well, including 5 stages of inter‑stage temporary plugging and 6 stages of intra‑stage temporary plugging in casing‑deformed intervals. The average post‑plugging pressure increases were 9.0 MPa and 5.6 MPa, respectively. Field microseismic monitoring shows obvious differences in event points before and after temporary plugging, verifying the effectiveness of the proposed technology.