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.

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 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.

The carboxyl nitrile hard glue wastewater contains raw materials, by-products and some auxiliary materials that are not fully involved in the reaction, and has the characteristics of high chemical oxygen demand (COD), high mass concentration of Pull apart powder（BX）, high viscosity and toxicity, resulting in the poor operation of the water treatment process. The pretreatment process with "air flotation, membrane separation and ozone oxidation" as the core was adopted to remove COD and decoking powder from carboxyl nitrile hard adhesive wastewater, so as to improve the biodegradability of wastewater. This pretreatment process had problems such as rubber caking and blocking, filter device blocking and so on, and the overall operation effect was poor. The pretreatment process was improved by increasing the influent flow rate to 105 m³/h, increasing the chemical backwash time and backwash frequency, adjusting the ozone quality concentration to 35 mg/L, and decreasing the height of the packing layer of the ozone catalyst layer to 650 mm. The results show that when the effluent COD is stable at about 1 100 mg/L, the mass concentration of BX is maintained at about 40 mg/L, and BOD/COD (BOD is the ratio of biological oxygen demand) is about 0.30, the influent conditions of the subsequent process can be met, and the stable operation of the system can be ensured.

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.

With the rapid growth of natural gas demand, there is an urgent need to consider the production, supply, storage and marketing structure of natural gas pipeline network, optimize the natural gas sub-customer sales scheme based on system analysis and decision-making theory, and maximize the profitability and economic benefits. With the objective of maximizing the annual total benefit of the natural gas sales pipeline network of the provincial company, taking the gas supply volume from the gas source, the pipeline transmission volume, and the sales volume of the customers as the decision-making variables, and taking into account the node flow balance constraints, the upper and lower limits of the gas volume of the production, supply, storage, and marketing links, the total sales volume of the sub-province constraints, etc., we optimize the gas procurement costs, pipeline costs, storage and transfer costs of storage reservoirs and LNG receiving stations and the customer sales revenues of the gas supply network of the industry chain in the upstream, midstream, and downstream segments. The customer sales revenue adopts the step pricing method, establishes the mathematical model of natural gas customer sales volume optimization, and selects GUROBI solver as the optimization calculation tool to solve the model. The model is tested on the basis of basic data of natural gas pipeline network of a province in the next 10 years to maximize the benefits while meeting the customers' natural gas demand, which verifies the reasonableness and accuracy of the model, and provides advanced analytical tools and technical methods for improving the quality and increasing the efficiency of the natural gas sales business.

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.

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.

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.

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.

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.

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.

In order to study the effect of hydrocarbon group composition on physical and chemical properties of jet fuel, the coal?based kerosene and biogenic aviation fuel were added to No.3 jet fuel respectively, and the seventeen physical and chemical properties of jet fuel were tested according to the experimental methods specified in GB 6537—2018《Jet Fuel No.3》. The results showed that hydrocarbon group composition was the primary factor affecting 8 physicochemical properties of blended jet fuel. As the mass fraction of paraffin increased or the mass fraction of naphthene decreased, the 10% recovery temperature, 50% recovery temperature, final boiling point, freezing point, kinematic viscosity at -20 ℃, and smoke point generally decreased monotonically, while density and net calorific value per volume increased monotonically. Hydrocarbon group composition was a non?primary factor affecting the remaining 9 physicochemical properties. An increase or decrease in paraffin mass fraction led to a decrease in flash point and naphthalene hydrocarbon volume fraction, whereas paraffin and naphthene mass fractions had negligible effects on net calorific value per mass, corrosiveness, thermal stability, gum mass concentration, water reaction interface condition, water reaction separation degree, and water separation index. When blending aviation alternative fuels with traditional jet fuel, the physicochemical properties of the blended fuel can be predicted to a certain extent based on the influence rules of hydrocarbon group composition on jet fuel properties, thereby reducing experimental trials and improving efficiency.

Optimal allocation of gas supply reliability is an important part of gas supply reliability of natural gas pipeline system.In order to study the optimal allocation scheme of gas supply reliability with the lowest cost,a cost function model based on the gas supply capacity of the pipeline system was constructed.To address the limitation of traditional intelligent optimization algorithms (e.g.,Particle Swarm Optimization) that overlook constraints during iterative updates,this research proposed a novel Exterior Penalty Function Method for optimizing gas supply reliability.This method transformed constraints in the allocation model into penalty function terms,established a revised objective function,and converted the constrained allocation problem into an unconstrained extremum problem.Applying this method to a practical pipeline system,optimal gas supply reliability allocation values were derived.The results demonstrate that the Exterior Penalty Function Method significantly reduces computational time without compromising accuracy.The allocation outcomes exhibit robust convergence and align with engineering practicality.By clarifying the optimized allocation values of unit gas supply reliability and comparing them with the current reliability,the weak units in the gas supply system can be identified,providing a scientific basis for improving the gas supply reliability of pipeline systems.

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.

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.

In order to improve the accuracy of magnetic azimuth measurement,it is often necessary to establish a more accurate local geomagnetic model to obtain precise magnetic declination information.Compared with global geomagnetic model, local geomagnetic model contains magnetic anomaly information caused by underground magnetic ore veins at the surface.Considering the different burial depths and sizes of underground magnetic veins,their effects on magnetic declination at different borehole depths differ significantly.Therefore,it is necessary to consider the correction of the azimuth angle of medium and deep wells under the influence of underground magnetic veins.Based on ANSYS Maxwell numerical simulation software,the geomagnetic field model under the influence of magnetic veins of different burial depths and sizes was established.Through numerical simulation method and actual drilled borehole trajectory of a medium?deep well (Z well),a method of azimuth correction was given to quantitatively analyse the influence of underground magnetic veins on the azimuth and borehole trajectory.The results of the study show that the effect of underground magnetic veins on the azimuth of drilling within the 2 000 m thickness stratum is about 0.6° under the condition that the magnetic veins are buried at a depth of 2 100 m.After considering the influence of underground magnetic veins,the borehole trajectory is inevitably offset,and the offset increases with the depth of the well,which may cause off?targeting and other accidents for medium and deep wells.Therefore,it is of great significance to consider that the azimuth correction under the influence of geomagnetic veins can strongly improve the azimuth measurement accuracy and realise accurate guidance.

Indeno[1,2?d]pyridazine derivatives have wide applications in pesticides,pharmaceuticals,and other fields due to their excellent biological activities.Therefore,the development of rapid and efficient synthetic methods for these compounds has attracted increasing attention from researchers.A novel acid?catalyzed cyclization reaction between allylbenzene and tetrazine was designed.Reaction intermediates were trapped,and their structures,along with those of the products,were characterized using nuclear magnetic resonance spectroscopy.The results indicate that the reaction proceeds through intermolecular [4+2] cycloaddition and intramolecular Friedel?Crafts alkylation processes,enabling one?step synthesis of indeno[1,2?d]pyridazine derivatives.The reaction also exhibits a broad substrate scope and good functional group compatibility,yielding a series of indeno[1,2?d]pyridazine derivatives with 67%~95% yields.In gram scale experiments,the target product was obtained with an 81% yield, demonstrating the potential practical value of this reaction.

The propane dehydrogenation reaction is thermodynamically unfavorable, tnecessitating kinetic control through optimized process conditions. Single?factor experiments and multi?factor Response Surface Methodology (RSM) were employed to analyze and optimize propane dehydrogenation conditions over a PtSnK/Al?O? catalyst, followed by experimental verification. First, single?factor experiments determined the range of values for the factors to be studied in the response surface methodology. Then, a Box?Behnken design with three factors (reaction temperature, space velocity, and hydrogen?hydrocarbon ratio) was used to optimize the reaction conditions of propane dehydrogenation by multifactor response surface methodology with propylene selectivity as the response value, and finally, the optimized process conditions were experimentally verified. Results indicated that the optimal reaction temperature, VHSV, and H?/C?H? molar ratio were 605 ℃, 2 200 h?1, and 0.6, respectively. The theoretical propylene selectivity prediction under these conditions was 93.01%. The order of influence weight from largest to smallest was reaction temperature > H?/C?H? molar ratio > VHSV. Experimental verification yielded a propylene selectivity of 93.00% and propane conversion of 32.00%. Experimental determination of propylene selectivity is consistent with RSM predictions, confirming the model's reliability and credibility.

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.

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 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.

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.

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.

Sodium vanadium phosphate (Na₃V₂(PO₄)₃, abbreviated as NVP）, exhibits unique advantages in sodium?ion batteries due to its excellent thermal stability and broad sodium?ion transport channels. However, the expensive vanadium raw materials have diminished the attention on the commercial development of NVP. In this work, NVP was successfully synthesized using solid?state methods from NaVO₃, a byproduct from the upstream of the vanadium extraction industry, and compared with NVP synthesized from V₂O₅ and NH₄VO₃ at different calcination temperatures. The results indicate that the vanadium source has a significant impact on the structure and morphology of NVP, which further influences the battery capacity and rate performance. NVP prepared using NaVO₃ at 750 ℃ exhibits excellent electrochemical performance, achieving an initial high capacity of 105.6 mA·h/g at 0.1 C, and still obtaining high capacities of 101.5, 99.9, and 92.9 mA·h/g at subsequent rates of 1.0, 2.0, and 5.0 C, respectively. Moreover, it achieves a reversible capacity of 97.1 mA·h/g and a high capacity retention rate of 94.6% after 300 cycles at 1.0 C, and retains 94.0% capacity after 500 cycles at 5.0 C. This simple, efficient, and cost?effective synthesis strategy provides a reference for the scaled?up production of NVP.

The efficient production of hydrogen as a clean energy carrier relies on the performance optimization of electrocatalysts for the hydrogen evolution reaction (HER).Although platinum (Pt)?based catalysts exhibit exceptional HER activity,their high cost and stability issues can be mitigated through rational design of the support material.Nickel hydroxide (Ni(OH)?) has emerged as a promising support due to its unique proton conductivity,interfacial modulation properties,and stabilizing effects on Pt. However,a systematic understanding of the structure–activity relationship between Ni(OH)? supports and Pt nanoparticles,as well as the impact of synthesis parameters on catalytic performance,remains lacking.This study focuses on the regulation of Ni(OH)? support phase evolution and Pt interfacial growth behavior by hydrothermal synthesis temperature.By analyzing the structure–performance relationship through the synthesis parameter–microstructure–catalytic performance correlation mechanism),the synergistic effects of temperature on the crystallinity of the support,Pt particle size distribution,and interfacial electronic structure were elucidated.Experimental results indicate that the Pt@Ni(OH)? catalyst synthesized at 100 ℃ exhibits outstanding HER activity in 1 mol/L KOH electrolyte,with overpotentials of only 5 mV at 10 mA/cm2 and 62 mV at 100 mA/cm2,along with a Tafel slope of 70.0 mV/dec.After 50 hours of continuous operation,the electrode maintains nearly unchanged HER performance,demonstrating remarkable stability.

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.

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.

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 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.

Carbon dioxide capture,utilization and storage(CCUS) is a crucial strategy for mitigating the greenhouse effect and reducing CO? emissions.As the predominant technology for large?scale commercial CO? capture,the high energy consumption of the absorption method seriously restricts the popularization and development of CCUS technology.This paper focuses on the energy?saving path in the CCUS process,and systematically reviews the latest research progress and achievements in three key directions: The research and development of new absorbents,design of new high?efficiency reactors,coupling of CO₂ capture and conversion process.The results show that the new absorbent reduces the energy consumption of the absorption reaction process,the high?efficiency reactor greatly enhances the mass transfer,and the integrated coupling technology realizes energy saving and consumption reduction from the process source.Future research needs to focus on the verification of the industrial application of new absorbents,the stability and cost control of long?term operation of reactors,and the further improvement of the economic efficiency of absorption and conversion integration technology,so as to promote the large?scale application of low?energy CCUS technology and help achieve the "double carbon" goal.

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.

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.

In the process of heavy oil thermal recovery using SAGD (Steam?Assisted Gravity Drainage) technology, conventional thermal recovery boilers are mainly used for heat generation. When steam is used as the heat?carrying medium, problems such as a short water breakthrough time and low heat utilization efficiency are often encountered, resulting in low oil recovery. Changing the heat generation method to reduce water injection while ensuring heat injection is of great significance for thermal recovery.Based on the analysis of directional chemical reaction products and combined with large?scale three?dimensional physical simulation experiments, the feasibility of directional chemical reactions was verified, the expansion law of the temperature field in directional chemical reaction?assisted SAGD was clarified, and the characteristics of production curves at different mining stages were analyzed and evaluated.The results show that among the products of the directional chemical reaction, the liquid fluid is mainly C₅-C₂₀, and the gaseous substances are mainly CH₄ and CO₂; the final recovery degree of SAGD development assisted by directional chemical reaction products is 76.59%, which is 19.99 percentage points higher than that of pure SAGD. The research further verifies the mechanism of the directional chemical reaction?assisted SAGD efficiency?increasing technology, providing a theoretical basis and technical support for field applications.

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.

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%.