Using sodium lignosulfonate and copper chloride dihydrate as raw materials, and activated carbon modified materials under different synthetic conditions were prepared by calcination under N2 atmosphere by impregnation and activation. The structure and surface morphology of the prepared materials were studied by X-ray diffraction (XRD), infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS) and other testing methods. Taking K2Cr2O7 solution with mass concentration of 20 mg/L as the research object, the Cr(Ⅵ) content in the solution was detected by Diphenyl carbamide chromogenic method, and the adsorption capacity of the prepared activated carbon modified materials was calculated. According to the experimental results, when the proportion of copper is 20% and the calcination temperature is 700 ℃, the adsorption performance of the material is the best, and the adsorption capacity is 72.2 mg/g. The adsorption process conforms to the Langmuir monolayer adsorption and Pseudo-second-order kinetics.
Metal corrosion is an irreversible destructive behavior, therefore, the research of anticorrosive coatings has become a vital research topic in various fields. With the development of recent years, the single protective form of anti?corrosion coating is no longer sought after, the advent of barrier/self-healing coatings has added a significant complement to anti?corrosion coatings and has become one of the most widely studied topic today. Subsequently,new anti-corrosion forms such as ion exchange, hydrophobicity and intelligent self-warning have appeared on the market. Dual/multi-functional anti?corrosion coatings that integrate self-healing, barrier properties, hydrophobic properties and intelligent self-warning properties have also become research topics in recent years. In this paper, the research progress of barrier/self-healing bifunctional anti?corrosion coatings, other dual-function anti-corrosion coatings (ion exchange/self-healing coatings, hydrophobic/self-healing, self-warning/self-healing) and multi-functional anti-corrosion coatings are reviewed, and the future development direction of more intelligent and green dual/multi-functional coatings is prospected.
There are several sets of formation pressure systems in Y structure of block X in Bohai Sea. Shahejie Formation and its upper strata are sedimentary undercompacted layers. dc index method is adopted to monitor formation pressure. The Mesozoic buried-hills are widely distributed in medium acid volcanic rocks, which are non-sedimentary underpressure layers. The formation pressure monitoring method of Sigma index is used to monitor the formation pressure. The real drilling shows that the formation pressure monitoring method of dc index has good applicability in the formation profile pressure monitoring dominated by sand and mudstone. The formation pressure monitoring method of Sigma index has a good application effect in the non-sand mudstone formation profile pressure monitoring, and the combined application of the two provides effective technical support for the smooth drilling. The application of Sigma index formation pressure monitoring method in deep and ultra?deep layers effectively improves the accuracy of the deep and ultra?deep layer pressure monitoring technology while drilling. The practical application shows that the results of formation pressure monitoring while drilling are in good conformity with the measured formation pressure results, and the formation pressure monitoring method of Sigma index has the value of popularization and application in deep and ultra-deep formation.
Deep and ultra-deep carbonate oil and gas reservoirs, with their vast reserves and immense potential, have emerged as critical strategic assets in global energy supply. However, the complex challenges posed by high-temperature, high-pressure environments, intricate pore-throat structures, and the coexistence of macro-pores, dissolution cavities, and fractures make traditional exploration and production technologies insufficient to manage such complexity. As exploration and development progress, precise reservoir characterization and seepage behavior research face significant hurdles, including advanced modeling, complex seepage experiments, and accurate description of reservoir properties. Therefore, this review offers an in-depth analysis of the latest developments and key challenges in the characterization and seepage behavior of deep and ultra-deep carbonate reservoirs. It provides a comprehensive summary of cutting?edge methods for detailed microstructural reservoir characterization and multi?attribute seismic interpretation techniques enhanced by artificial intelligence. The paper also explores the application and success of multi?scale characterization approaches in complex reservoirs,while outlining the primary technical strategies and emerging trends in reservoir identification and description. Additionally,the article emphasizes recent advancements in understanding seepage characteristics under high-temperature and high?pressure conditions in deep carbonate reservoirs, focusing on multi-scale seepage theory and gas-water two?phase flow mechanisms. By examining experimental data and theoretical models from both domestic and international research, the review highlights current challenges and future directions in seepage studies, providing valuable insights for the development and efficient exploitation of deep and ultra?deep oil and gas reservoirs.
Microbial dewaxing of crude oil is an efficient and simple method. In order to further improve the paraffin degradation rate of microorganisms, two strains L and K were used to form paraffin degradation mixed bacteria, and their degradation conditions were optimized. The factors affecting the degradation of mixed bacteria (culture temperature, initial pH value of culture medium, salt concentration, and V(L strain )/V(K strain)) were determined by orthogonal experiment and single factor experiment. Box-Behnken method was used to design four?factor three?level experiment and response surface optimization, and a mathematical model was established to explore the best conditions for the degradation of paraffin by mixed bacteria. The experimental results showed that the influence of four single factors is as follows: V(L strain)/V(K strain)>culture temperature>salt concentration>initial pH value of culture medium. Their primary term, secondary term and individual interaction term had significant influence on the paraffin degradation rate. The optimal experimental operating conditions for the mixed bacteria to degrade paraffin were determined as follows: culture temperature 37.2 ℃, initial pH value of culture medium 7.3, salt concentration of culture medium 1.2%, ratio of mixed bacteria V(L strain)/V(K strain)=1.0∶1.6, and paraffin degradation rate 58.67%. The mixed bacteria were used to act on crude oil under the optimized conditions, and the biodegradation rate was 41.38%,have good application prospects.
Poly (butyleneadipate-co-terephthalate) (PBAT) was used to toughen poly (lactic acid) (PLA), and a fully biodegradable high impact PLA/PBAT composite was prepared. To improve the interface compatibility between PBAT and PLA, PBAT grafted glycidyl methacrylate (GMA)(PBAT-GMA) compatibilizer was prepared by the melt grafting method. The effect of the mass fraction of compatibilizer on the properties of PLA/PBAT composite was studied. The results show that with the increase of PBAT-GMA mass fraction, the impact strength of the composites is significantly improved. When the PBAT?GMA mass fraction is 30%, the impact strength of the composites reaches 64.8 kJ/m2, and the elongation at break is 289.9%; the compatibilizing mechanism is the epoxy groups on PBAT?GMA can react with the end groups of PLA, which effectively improves the interfacial compatibility between PLA and PBAT.
The environmental contamination caused by tetracycline hydrochloride (TC) has aroused widespread concern, photocatalytic degradation of TC has become an effective method. CeO2 was prepared by coprecipitation method, and solvothermal synthesis of CeO2@UiO-66 composite catalysts. The prepared catalysts were characterized by FT-IR, XRD, SEM and EDS respectively, and the effects of the amount of CeO2, catalyst mass concentration and H2O2 mass fraction on the photocatalytic degradation of TC were also investigated. The results showed that CeO2@UiO?66 was successfully synthesized. When the amount of CeO2 substance is 25 mmol, the mass concentration of TC solution is 20 mg/L, the mass concentration of catalyst is 0.2 g/L, and the mass fraction of H2O2 is 2%, CeO2@UiO?66 photocatalytic effect is the best, and the TC degradation rate reaches over 98% when irradiated by UV lamp for 70 min. The free radical trapping experiments showed that holes and ·OH were the main contributors in the photocatalytic process. In addition, after six cycles, the degradation rate of TC composite photocatalyst can still maintain above 85%, which indicates its good stability.
Co@CNT/CN nanocomposites were obtained by a simple one-pot co?precipitation method using dicyandiamide, glucose and cobalt nitrate as raw materials. The effect of carbon nanotubes (CNTs) on the catalytic activity of Co was investigated by X-ray diffraction (XRD) and electrochemical tests. The results show that Co@CNT/CN can be obtained only at the calcination temperature of 850 ℃. And after electrochemical performance test, it was found that the electrocatalytic activity of Co@CNT/CN material with carbon nanotubes was significantly higher than that of other samples, mainly because carbon nanotubes have special conductivity, but also can promote the separation of Co elemental, reduce the agglomeration phenomenon, so as to obtain higher electrocatalytic activity.
The reduction of graphene oxide(GO), in?situ loading of SnSe and interface assembly were achieved simultaneously by microwave method, and the reduced graphene oxide(rGO)?supported the petal?shaped SnSe (SnSe/rGO) composite was successfully prepared. The SnSe/rGO was characterized by Raman spectroscopy, X?ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM), and the effects of different rGO contents for SnSe/rGO composite on the electrocatalytic oxygen reduction reaction(ORR) were investigated. The results indicated that there was an interaction between SnSe and matrix rGO, and Sn-C and Sn-O-C bonds were used as bridges of charge transfer. The intimate interconnection between the petal?like SnSe and the rGO formed a robust three?dimensional mesh structure, which served to reinforce the overall structural integrity of the catalyst, preventing its collapse. Based on this, the optimized SnSe/10%rGO catalyst (10rGO means that the mass fraction of rGO is 10%) exhibited excellent ORR activity with a limiting current density of 3.79 mA/cm2, an onset voltage (vs.RHE) of 0.85 V, and an electron transfer number of 3.10. Meanwhile, the SnSe/10%rGO catalyst performed the electrocatalysis long?term stability superior that of commercial 20%Pt/C (20%Pt means that the mass fraction of Pt is 20%) with the current density remaining 81.15% of the start value after 20 000 s of reaction. The present work offers insights into the preparation of non?precious metal cathode oxygen reduction catalytic materials for fuel cells.
In oil and gas extraction, coiled tubing technology has attracted much attention because of its advantages such as fast operation time, little damage to the formation low labor intensity, etc. The research of coiled tubing technology is a systematic project involving many aspects. This paper first starts the discussion from the domestic and international literature published and the main research scholars review the development process of coiled tubing technology, and summarise the relevant achievements existing in China. At present, the coiled tubing technology is in the stage of rapid development, but the research of coiled tubing in ultra-deep wells is minimal. The authors describe the relevant research carried out by the team on the downhole accessibility of coiled tubing in ultra-deep wells, the extension of the horizontal section of coiled tubing, the optimization of the construction parameters of coiled tubing operation, and the downhole safety assessment of coiled tubing operation. According to the current status of coiled tubing technology research in ultra-deep wells, it is suggested to carry out the research related to the real-time warning technology of coiled tubing fatigue life based on the digital intelligence technology, the ability of tractor?driven coiled tubing extension, and the research and development of high?temperature?resistant tools and fluids, to solve the technical difficulties of coiled tubing operation in ultra-deep wells.
Direct flame impingement heating technology is widely used in the field of steel heat treatment processes and is currently fueled by natural gas. Hydrogen, as a clean energy source and its high laminar flame propagation speed, combined with natural gas will improve the fuel combustion speed and reduce the emission of carbon oxides and nitrogen oxides. In this paper, a numerical model of direct flame impingement heating of steel plate was established using Fluent, and the heat transfer characteristics of direct flame impingement heating of steel strip were investigated under different hydrogen doping, Reynolds number, and factorless distance conditions. The results show that the temperature and heat flow density of the steel plate of the heated target decrease with the increase of hydrogen doping from 0 to 25% at a heating time of 10 s. The temperature of the steel plate stationary point decreases from 385.36 K to 374.31 K, and the heat flow density of the steel plate stationary point decreases from 154 828 W/m2 to 137 926 W/m2. With the increase of Reynolds number from 13 400 to 33 600, the steel plate stationary temperature increased from 347.04 K to 450.90 K, the pressure increased from 14.93 Pa to 136.53 Pa, but the uniformity of the temperature and pressure of the steel plate deteriorated gradually. The increase of the causeless distance from 25 to 45 made the temperature of the steel plate stationary point decreased from 442.42 K to 344.36 K, and the pressure was reduced from 106.00 Pa to 24.81 Pa and the distribution was more inhomogeneous.
To study the influence of hydrogen mixing ratio on the leakage of natural gas pipelines, a mathematical model for the leakage and diffusion of directly buried high?pressure hydrogen mixed natural gas pipelines was established based on computational fluid dynamics theory and numerical simulation method.The leakage status, volume fraction distribution of hydrogen mixed gas,and the distribution of soil pressure and gas velocity around the pipeline were analyzed under different hydrogen mixing ratios.The results show that with the increase of hydrogen mixing ratio, the explosion radius of hydrogen mixed gas in the atmosphere will gradually decrease,and the range of high?pressure area around the pipeline will gradually decrease,and the gas flow rate at the leakage port will gradually increase.When the hydrogen mixing ratio is 30%,the explosion radius in the atmosphere is reduced by 43%,and the gas flow rate at the leakage port is increased by 68%.This provides a theoretical reference for the safety and emergency repair of hydrogen?doped natural gas pipelines and has important practical significance for promoting the large?scale application of hydrogen?doped natural gas.
Poly (arylpiperidine) anion exchange membrane (AEM) has been widely studied in anion exchange membrane fuel cells (AEMFCs) and alkaline electrolyzed water due to their excellent alkali resistance and stability. In this work, poly (triphenyl fluorene piperidine) (PTDP) AEM was prepared from 9,9?diphenylfluorene monomer with distorted large volume structure, and hydrophilic large volume cyclodextrin crosslinking agent (β?CD?Br7) was introduced on this basis, which can control the microphase separation structure in AEMs. The prepared qPTDP?10?CD5 AEM with 5% crosslinker content reached a high conductivity (130.2 mS/cm at 80 ℃). After the membrane was treated in 1 mol/L NaOH at 80 ℃ for 2 000 h, its conductivity retention was 94.3%, showing good stability. The H2/O2 fuel cell assembled with qPTDP?10?CD5 yielded a peak power density of 1 490 mW/cm2 at 80 ℃. In the durability test, the fuel cell assembled with qPTDP?10?CD5 showed a voltage retention rate of 89.7% after 30 h, showing good cell performance.
Protected amino acid compounds are often widely used as intermediates of drug molecules and functional material intermediates. The high efficiency of Boc-protected amino acid esters provides an important prerequisite for their subsequent conversion in the entire process. Boc-tert-butyl phenylalanine was selected as the raw material, and the process of selectively removing the Boc protecting group while retaining the protecting group of tert-butyl ester to generate tert-butyl phenylalanine hydrochloride was studied. Under room temperature or low temperature conditions, the yield of about 82% can be achieved by deprotection under acidic conditions, and the reaction conditions are simple and mild, and the cost of process equipment is low, which realizes simple operation, economical benefits and environmental protection.
A series of novel anion exchange membranes (AEMs) were prepared by constructing semi?interpenetrating polymer networks (sIPN) based on imidazole functional brominated polyphenyl ether (ImF?BPPO) and quaternary ammonium polyvinyl alcohol (QPVA). The effects of different contents of QPVA on the comprehensive properties of the composite membranes were systematically studied, the structure of the series composite membranes was analyzed by 1H?NMR and FT?IR, and the morphology of composite membrane was investigated by SEM, and the ion exchange capacity, water uptake and conductivity and other properties of the composite membranes were tested. The results show that the prepared series of composite membranes have good compatibility and no obvious phase separation phenomenon. When the mass fraction of QPVA was 40%, the water uptake and swelling rate of the composite membrane were 58.2% and 24.6%, respectively. At 80 ℃, the conductivity of the composite membrane reached 67.24 mS/cm. After soaking in 6 mol/L KOH alkaline solution for 168 h, about 90% of the initial conductivity was still retained, indicating that the membrane had good conductivity and alkali resistance stability.
A base?catalyzed 1,6?conjugate addition of p?QMs for the preparation of diaryl methyl ethers (thioether) has been developed with 37% to 95% yields, which realized the solvolysis reaction between p?QMs and alcohol (thiophenol) under the catalysis of 20% NaOH. The method features easy operation, mild condition and good functional tolerance. A gram scale experiment was examined in 80% yield, which provides possibility for potential application and transformation in later stage.
The hydrocracking unit is a Class A fire hazard device, which can be susceptible to fire and explosion accidents due to equipment failure. Therefore, it is essential to identify and quantitatively analyze the risk factors. In this paper, qualitative HAZOP, steady-state simulation, dynamic simulation and FTA are combined. Taking process flow of the absorbing-stabilizing system of an actual hydrocracking unit in a refining company as an example, and the quantitative risk analysis is carried out for the deviation of "high column pressure" of the absorption and desorption column and "high column temperature" of the naphtha stabilisation column. With the help of Aspen Plus software, the steady-state and dynamic simulation under dangerous conditions is carried out, and the probability of the consequences of the dangerous accident is calculated by FTA method. The results show that this method can help experts understand the propagation process of the accident, master the safety response time of the personnel, which is conducive to the prevention and timely treatment of accidents, and effectively improve the intrinsic safety level of the hydrocracking units.
Using the synergistic effect of surfactant mixture to reduce oil?water interfacial tension and crude oil viscosity is an important method to improve oil recovery in recent years.The content of each component of crude oil produced from each oil field is different, so it is necessary to screen the suitable surfactant according to the component content.In this paper, the interfacial tension and emulsifying properties of sodium dodecyl benzene sulfonate (SDBS) and lauryl glucoside (APG1214) in Liaohe crude oil were studied by rotating drop interfacial tensiometer and bottle test method. The interfacial tension was studied by changing different compounding ratios, salinity and pH value, and the viscosity of the emulsion was measured by viscometer.The results show that the interfacial tension between oil and water can be reduced and the stable heavy oil emulsion can be formed by adding proper amount of inorganic salt in combination of surfactant.
In this study, the optical properties of 3D carbon ball were theoretically investigated by using Density?Functional Theory (DFT) and wave function analysis. The electron?leaping mechanism in the Ultraviolet?visible (UV?vis) absorption spectrum was investigated. The electronic excitation properties of 3D carbon ball were investigated by Transition Density Matrix (TDM) and Charge Density Difference (CDD). Raman spectra were calculated and the vibrational modes of the 3D carbon ball were further explained. Meanwhile, the interaction between 3D carbon ball and the external environment was investigated using Electrostatic Potential (ESP), and the degree of electron delocalization of 3D carbon ball was investigated based on the magnetic induction current under the applied magnetic field.It is shown that the absorption spectra of three?dimensional carbon spheres are mainly in the ultraviolet region and that they have a strong electron delocalization capability. This study can provide a theoretical basis for the application of other 3D π?conjugated molecular structures in linear and nonlinear optics.
A model of a micro-texture tool featuring various textures such as micro-pits, parallel grooves, vertical grooves, and oblique grooves was developed. The impact of these micro-texture tools on the turning process of titanium alloy was investigated using the finite element analysis software ABAQUS. Through an examination of cutting force, friction coefficient, cutting temperature, and surface residual stress for micro-texture tools with distinct morphologies, the optimal micro-texture morphology was determined. The findings reveal that micro-texture tools can effectively reduce the cutting force, friction coefficient, and cutting temperature while transforming surface residual stress from tensile to compressive on the workpiece. Furthermore, with increasing cutting speed, cutting force and cutting temperature rises, friction coefficient decrease, and the residual stress on the workpiece surface shifts from compressive to tensile stress, exhibiting an ascending trend.
Ultra?deep wells of over 10 000 meters have been successfully drilled in China, and deeper breakthroughs has been made in drilling and completion equipment technology, which indicates that China has achieved a significant milestone in the field of oil exploration and development. It is crucial to improve drilling efficiency and ensure safety in this context. Intelligent drilling and completion technology is a core solution to the challenges faced in the industry. It offers significant advantages in improving drilling efficiency and safety. By integrating advanced automation control, real?time data monitoring, and machine learning technology, it optimizes drilling operations. This not only improves drilling efficiency but also dramatically enhances drilling and completion safety. This paper summarizes the current development status of intelligent drilling and completion equipment technology. It proposes a trinity research approach that includes automation control, real?time data monitoring, and machine learning technology. The paper focuses on analyzing the development journey and technological innovation of domestic and international innovative equipment, such as intelligent drill bits, intelligent guiding tools, intelligent drill pipes, intelligent slip sleeves, and intelligent drilling rigs. To achieve comprehensive development of intelligent drilling and completion equipment technology in the future, it is recommended to utilize artificial intelligence, intelligent optimization algorithms, and foster domestic and international cooperation.
A power cycle (KC-TORC) combining a Kalina cycle and a three?stage organic Rankine is proposed to address the problems of large flue gas discharge with high temperature and low flue gas outlet temperature that is easy to cause corrosion of industrial pipelines in the industrial production process. A circulation system was constructed by using the method of thermodynamic simulation, taking industrial flue gas as the heat source and liquefied natural gas (LNG) as the cold source,and the effects of kalina cycle evaporation temperature, LNG post?pump pressure and three?stage organic Rankine cycle (ORC) turbine inlet temperature on the thermodynamic performance were analyzed by varying the flue gas outlet temperature. The results show that the maximum exergy efficiency is 62.89% at a flue gas outlet temperature of 30 ℃ and a Kalina cycle evaporation temperature of 112 ℃. The maximum thermal efficiency is 32.09% at a flue gas outlet temperature of 120 ℃ and three?stage ORC turbine inlet temperature of 160 ℃, and the net output power can be up to 2.04 MW. The annual NAV could be up to 5.773×106 dollars. The KC?TORC power cycle shows good advantages in thermodynamic and economic aspects, which is important for environmental protection.
ZnO has a strong UV absorption capacity, but also has a high photocatalytic performance, which limits its application in the field of UV shielding. In order to explore the possibility of ZnO's application in the field of ultraviolet shielding, this article uses VASP to construct a ZnO/CeO2 heterojunction and performs electronic and optical simulation calculations on it. Then lignin is used to combine with the synthesized ZnO/CeO2 heterojunction to prepare lignin-modified nano-ZnO/CeO2 heterojunction. Through the FT-IR, XRD, SEM, UV-Vis-DRS means the characterization of samples. The UV shielding properties of the synthesized samples were investigated with methylene blue as the protection object. The results show that the light absorption performance of the samples at 280~420 nm is better than that of ZnO/CeO2 samples. The retention rate of methylene blue for 70 min under UV irradiation was 77.92%, indicating that the synthesized sample was a UV shielding material with high UV shielding properties and low photocatalytic activity.
Card sleeve joints are widely used in the connection of hydraulic and pneumatic equipment such as oil and gas pipelines, and its connection reliability has an important impact on the safety of oil and gas pipelines. However, there is no report on the influence of external working conditions on the stress characteristics of the thread of card sleeve joints in oilfield ground pipelines. A three?dimensional model of the double card sleeve joint was established using SolidWorks software; The maximum equivalent stress (Von Mises stress) of the sleeve joint was numerically analyzed using ANSYS finite element software. The results indicate that within the yield limit, the greater the axial force, the better the sealing performance of the sleeve joint, while the internal pressure has little effect on the sealing of the pipe joint, and the risk of thread sticking due to excessive stress can be ignored; The influence of thread parameters on sealing performance is significant; The optimal pitch and number of threads for a sleeve joint with an outer diameter of 12 mm and an inner diameter of 9 mm are 1.5 mm and 7, respectively. The research results can provide theoretical basis and reference for the optimization of structural performance and scientific operation in the assembly process of card sleeve joints, which has important engineering significance.
Glass fiber (GF) reinforced nylon 6 (PA6) composites were prepared with a twin-screw extruder. The effects of GF mass fraction on the mechanical properties, thermal properties, density, water absorption and processability of PA6/GF composites were systematically investigated. The results show that the impact strength, tensile strength, flexural strength, flexural modulus, density and thermal deformation temperature of the composites increased with the increase of glass fiber content, while the water absorption and melt flow rate decreased with the increase of glass fiber mass fraction. The morphology showed that the GF was effectively wrapped and dispersed in the PA6 matrix when the GF mass fraction was increased up to 30%.
In some areas of Xinjiang, the dip angle of coal seams can reach 50 °. Unlike horizontal coal seams, fluids in high dip coal seams are severely affected by gravity, and the pressure propagation law of coalbed methane wells has special characteristics. The optimal drainage and extraction well position needs to be optimized. This article considers the gravity effect of formation water and establishes a pressure propagation model for single-phase drainage in steep coal seam, and verifies the correctness of the model.Then, the water production of fractured wells in the inclined reservoir is calculated under stable seepage conditions, and the optimal drainage well position is optimized. Finally, numerical simulation methods are used to study the pressure propagation laws of single wells and well groups in heterogeneous bounded inclined reservoirs. The results show that in a high dip coal seam with an inclination angle of 45 °, the position where the distance ratio between the drainage well and the upper and lower boundaries is 3 ∶ 1 is the optimal drainage well position; under the constant pressure drainage mode, there is not much difference in the pressure drop amplitude between the downward and upward tilt directions. In the constant speed depressurization and extraction mode, the pressure drop amplitude in the upward tilt direction is much greater than that in the downward tilt direction.
At present,most oil fields in China have entered the high water cut period,and the flow characteristics of produced fluid have changed, so it is possible to reduce the temperature of gathering and transportation.However,there are relatively few studies on the influence of pipeline materials on low-temperature gathering and transmission characteristics. Therefore, the characteristics of low-temperature gathering and transportation of high water content crude oil in steel pipe and fiberglass pipe are studied.The results show that the wellhead back pressure rises and the oil temperature at the end of pipeline drops slowly after the water content of the pipeline is reduced. The wellhead back pressure rises differently under different water content.When the water content is the same, the temperature of fiberglass pipe is lower than that of steel pipe, and the minimum water content of fiberglass pipe for low-temperature gathering and transportation is lower than that of steel pipe under the same condition.Based on the experimental data of viscosity wall temperature,the calculation models of different pipe materials are obtained,and the calculation results are accurate, which has a guiding significance for the feasibility judgment and safe operation management of the oil field in the high water cut period.
At present, the demand for clean energy is constantly increasing to achieve sustainable development of human society. Among numerous new energy storage and conversion devices, proton exchange membrane fuel cells (PEMFCs) can directly convert chemical energy into electrical energy. Therefore, PEMFCs have been considered to have the merits of high efficiency, safety and wide application, etc. The proton exchange membrane is the core component of PEMFCs. However, the trade?off of proton conductivity and mechanical strength has become the primary challenge to hinder the development of proton exchange membranes. Although significant progress has been made in improving the single performance, the mutual constraints of key technical properties restrict the development of proton exchange membranes. Most importantly, the road to the commercialization of fuel cells is thus tortuous. We believe that the development of flexible proton exchange membranes is a main strategy to solve this technical challenge. Based on this, this article summarizes the recent research progress on flexible proton exchange membranes,including flexible polymer materials, structural optimization, and flexible additive design, expecting to provide inspiration for breaking through the performance bottleneck of flexible proton exchange membranes.
The study of the micro high viscosity mechanism of heavy oil is of great significance for the efficient development of Bohai heavy oil. Therefore, aiming at the typical heavy oil reservoirs in Bohai Sea, the microscopic mechanism of high viscosity of heavy oil is analyzed and studied from the aspects of viscosity?temperature relationship, crude oil composition and component polarity, heteroatom distribution and asphaltene aggregate structure. The results show that compared with N oilfield in Bohai Sea, the content of alkanes and aromatics in L oilfield in Bohai Sea is lower, and the quality score of resins and asphaltenes is higher, reaching 29.95% and 9.76% (23.25% and 6.59% in N oilfield). The quality score of heteroatoms such as O,N and S are high, and the relative molecular mass of resins and asphaltenes are also high. The polarity of each component is strong, and the dipole moments of resins and asphaltenes reach 14.01 D and 17.94 D, respectively (9.12 D and 12.25 D in N oilfield ). These will lead to stronger intermolecular forces and stronger intermolecular association between resins and asphaltenes. The smaller asphaltene molecular spacing and the denser aggregate structure,which will eventually lead to higher viscosity of crude oil.
Through molecular dynamics simulation, the torsional deformation behavior of copper nanowires in different crystal orientations (Ⅰ: x[1 0 0] y[0 1 0] z[0 0 1], Ⅱ: x[1 0 1/8] y[0 1/8 0] z[-1/8 0 1], Ⅲ: x[1 0 1/4] y[0 1/4 0] z[-1/4 0 1]), different crystal orientation ratios (α1=1/6, α2=1/2, α3=5/6), and different numbers of twin interfaces (0, 2, 4) were studied, as well as the relationship between the shear stress and torsion angle of copper nanowires during torsion. The results indicate that change the orientation type contributes to enhancing the torsional mechanical properties of copper nanowires. Reducing the ratio of internal diameter to external diameter also improves the torsional mechanical properties of copper nanowires. Furthermore, decreasing the number of twin interfaces can strengthen the torsional mechanical properties of copper nanowires. The torsion process of copper nanowires can be divided into three stages: elastic, plastic and deformation failure. The research results provide a basis for investigating the torsion of high?strength copper nanomaterials.
The terrestrial gas reservoirs in the northeastern Sichuan region have reserves of over 100 billion cubic meters in the Xujiahe River. In the early stages, small?scale sand fracturing or acid fracturing were mainly used for production, but no significant breakthrough in productivity was achieved. Due to the tight and high fracture pressure of the Xujiahe reservoir, the construction displacement is limited, making it difficult to add sand and resulting in poor transformation effects. By conducting research on the guarantee technology for the operation of potential tapping wells, the Xujiahe potential tapping well wellbore treatment and fine pressure control technology have been developed, which has solved the problems of wellbore control and pressure control during construction operations caused by the coexistence of original test layers and large differences in ground pressure coefficients. The idea of tapping the potential of multiple layers in a single pipeline column has been proposed, forming a combination of large?diameter oil pipes and segmented fracturing pipelines with packers. The interactive operation of 140.0 MPa and 105.0 MPa wellheads meets the requirements of ultra?high pressure large?scale sand addition operations and later production. The application has been carried out in YB6, YL15, and YL171 wells, successfully achieving potential tapping operations in three old wells. A layer by layer fracturing of the four reservoirs was completed in the YL171 well using a single string, resulting in a production of 32 5000 cubic meters per day at a hydraulic pressure of 71.0 MPa.
The forward and reverse transportation simulation model was established by using SPS simulation software to simulate the forward and reverse operation process of A?Sai crude oil pipeline at low throughput. The change law of the oil temperature along the pipeline during the process of forward and reverse transportation is studied. The results show that the oil temperature along the pipeline decreases gradually under the steady state of forward transportation. The oil temperature drops first and then increases at the beginning of the reverse transportation, and then drops gradually after reaching the steady state.The oil temperature at the reverse inlet station decreases first and then increases slightly, and finally tends to be stable. The lowest temperature of crude oil in the process of forward and reverse transportation is the arrival temperature when the remaining crude oil is completely pushed out of the pipeline. In addition, the influence of inverse throughput on oil temperature drop during the inverse transportation was analyzed. The higher the inverse throughput is, the higher the lowest oil temperature in the process of inverse transportation is, and the faster the stable state of inverse transportation reaches. The temperature change of forward and reverse transportation obtained by SPS simulation analysis can provide certain basis for making the forward and reverse transportation scheme of A?Sai pipeline.
To investigate the influence of ordered micro texture design on the dynamic pressure effect of dry gas seal T‐groove, based on the principle of gas film lubrication, finite difference method was used to study the effects of ordered micro texture variables such as micro texture arrangement spacing, micro texture length, T‐shaped groove base length and width, and micro texture gradient inclination angle on sealing parameters. The design variables of four types of micro textures were compared. The results show that the micro texture of the T‐shaped groove can change the dynamic pressure effect of the groove itself, just like the structural parameters of the T‐shaped groove, but it does not change the dynamic law of the dry gas seal groove itself. The influence of microtexture variables on the opening force of T-shaped grooves in dry gas seals: microtexture gradient inclination angle>microtexture arrangement spacing>microtexture length and width>T-shaped groove base length and width amplification; The impact on leakage rate: microtexture length and width>microtexture arrangement spacing>T-shaped groove base length and width amplification>microtexture gradient inclination angle. The research results have certain reference value for the optimization and design of bi‐directional rotating end face gas film seals.
The combination of remote sensing image information extraction and artificial intelligence algorithms is an important technical tool for land use status survey, monitoring and management in land resources and environmental departments.Aiming at the problems of insufficient spatial information localization and inaccurate multi-scale target feature segmentation generated by U-net in remote sensing image extraction, a CA-Res2-Unet model incorporating an attention module into the head of Res2Net to replace the coding part of U-net is proposed, which aims to enhance the spatial localization and multi-scale feature information segmentation capability of U-net.Experiments were carried out on mainstream networks and improved models through the WHDLD public data set and the self-made data set of Shenfu New District. The results show that compared with the basic model, OA, MIoU and F1 indexes of the experiment on the WHDLD public data set and the self-made data set of Shenfu New District increased by 0.92%, 2.00%, 1.58% and 1.18%, 2.87%, 1.91%, respectively. The visual effect and quantitative indexes of the proposed method are superior to other mainstream semantic segmentation networks, which can provide scientific basis for the investigation of the status quo of regional land use and the decision-making of relevant departments.
A novel organic-inorganic hybrid material [Ag(DPPE)2]2[Mo4O10(CH3O)6]·2CH3OH (1) has been prepared by using [Mo4O10(CH3O)6]2- in polyoxometalate (POMs) as inorganic building block, 1,2-bis(diphenylphosphine)ethane (DPPE) as an organic ligand and silver nitrate as a silver source, through the means of a combination of solvothermal and conventional synthesis and via the self-assembly process. X-ray single crystal diffraction analysis shows that compound 1 is formed by electrostatic interaction with polyanion [Mo4O10(CH3O)6]2- and [Ag(DPPE)2]+ cationic units. In addition, the structure of the compound was analyzed by X-ray powder diffraction and fourier transform infrared spectroscopy. The stability was determined by thermogravimetric analysis, the band gap was determined by solid UV-visible diffuse reflection test, and the fluorescence spectra in methanol solution were measured. It was found that compound 1 showed good photocurrent response.
The crude oil produced by oil wells contains sediment, scale and other particles, which are deposited together with the wax in the process of crude oil pipeline transportation. It leads to a decrease in pipeline throughput, and may cause pipeline blockage and affect the safety of transportation in severe cases.The yield stress test and microscopic characteristic experiments show that there is a critical scale containing ratio in wax deposits of the influence of calcium carbonate scale on the strength of wax deposits. And it is found that the wax deposits containing scale will increase the breaking force on the wax layer and the pigging efficiency of the pig through the indoor pigging experiment of polyethylene pipeline. Based on the data of pigging experiment, a prediction model of pigging efficiency was established by using the π theorem. The model was validated by indoor experiments and third?party literature experimental data.
In order to improve the compatibility between rubber powder and matrix asphalt, the rubber powder was modified by microalgae bio?oil and compounded with SBS at 5% dosage to prepare modified asphalt. The changes of rubber powder before and after modification were analyzed by infrared spectroscopy and scanning electron microscopy; the dispersion of rubber in asphalt before and after modification was analyzed by viscosity, fluorescence and phase separation tests, and the mechanical properties and aging resistance of the modified asphalt were analyzed by dynamic shear rheology analysis and multiple stress creep recovery test. It was found that the incorporation of MB increased the proportion of light components in the mixing system, promoted the solubilization development of CR in asphalt, and improved the storage stability, viscoelasticity and rutting resistance of the modified asphalt.
In earthquakes and other natural disasters, there are often large and small debris on the road, which will affect the rapid passage of emergency vehicles. Installing lifting mechanism on the vehicle chassis is an effective way to solve this problem. However, the existing lifting mechanism lifting method is relatively single, occupies a large space, and is inconvenient to install underneath the vehicle. In addition, it also faces the problem that it can not be lifted flexibly with different working conditions. In order to solve these problems, this paper designs a metamorphic lifting mechanism based on the principle of metamorphic, which has the characteristics of variable topological configuration and variable degrees of freedom, and can complete the work task in different configurations according to different working conditions. For obstacles of different sizes, the mechanism can be elevated in one or two stages to realize rapid obstacle crossing. In this paper, after establishing the virtual prototype model of the metamorphic lifting mechanism, ADAMS software is used to carry out the configuration change dynamics simulation experiment, which investigates the dynamics of the vehicle in the process of configuration change and verifies the feasibility and stability of the mechanism.
Coumarins are a key class of heterocyclic lactone compounds, which have good biological activity. 3?sulfonyl coumarin derivatives were prepared by visible light promoted reaction of benzoalkynyl esters with sodium benzenesulfonate, and their reaction mechanism was studied. The results showed that under mild reaction conditions, 3?sulfonyl coumarin derivatives can be synthesized with moderate to good yields using sodium benzenesulfite as the precursor of sulfonyl radicals and persulfate as the oxidant through a cascade radical addition cyclization strategy, providing a concise, green, and efficient synthetic route for the preparation of functionalized coumarin derivatives.
The defect detection of non-woven fabrics can help enterprises improve production efficiency and save costs. Due to the local characteristics of the convolution kernel, the object detection algorithms based on CNN lack the global modeling of the image, and the detection effect is not ideal for defect detection with a large range of scale changes. Therefore, a non-woven fabric defect detection method is proposed based on the combination of Swin Transformer and YOLOv5, which encodes and decodes features through its powerful self-attention. The network can obtain a larger receptive field and fully relate to the context. The layered construction based on the feature pyramid of Swin coincides with the design of the neck of YOLOv5. It can help the network predict the target on the multi-scale feature map. On this basis, CBAM attention mechanism is introduced to help the network focus on important information. Through Mosaic and MixUp data augmentation, the data distribution is enriched and the robustness is increased. Finally, the anchor size of the prediction target frame is fine-tuned to make the regression prediction more accurate. The effectiveness of the proposed method is verified on the self-made data set, and the detection performance of non-woven fabrics is improved.
The chemical storage tank area is a place with a large number of hazard sources, and the dynamic risk of the storage tank area cannot be quantified and characterized by traditional emergency management methods. Therefore, based on PPRR theory, a quantitative evaluation model of fire emergency management ability of chemical tank farm was established, and the weight of evaluation index was determined by interval analytic hierarchy process. The improved fuzzy comprehensive evaluation method was used to quantitatively evaluate the fire emergency management ability of chemical tank farm. This model is used to evaluate the fire emergency management ability of chemical tank farm of M Petrochemical Company, and the accuracy of this model is verified. The results show that the evaluation score of fire emergency management ability of chemical tank farm of M Petrochemical Company is 3.35, which is consistent with the qualitative evaluation result, and the accuracy of this model is verified. The model can solve the problem of uncertainty of the importance degree of the indicators, and the improved fuzzy comprehensive evaluation method can point out the deficiencies and degree of chemical tank farm, which can provide a new way to perfect and improve the fire emergency management ability of the chemical tank farm.
Infrared thermal imaging technology is widely used in the study of precursor characteristics and early warning methods of rock failure. However, infrared radiation precursory features have many forms, so it has certain influence on the accurate early warning of rock instability. The failure and instability of rock are closely related to the evolution of strain energy, and the infrared radiation information of rock is related to the dissipation and release of strain energy. If the strain energy is combined with infrared radiation information, the rock failure and instability can be monitored and warned accurately. Based on this, in this paper, the release time of elastic energy is determined by the cusp mutation theory based on the energy evolution characteristics, which is combined with the infrared radiation anomaly information to determine the precursor of rock failure and instability. The results show that with the sudden drop of the elastic energy curve, the infrared radiation synchronization appears abrupt change. The elastic energy release time of sandstone predicted by constructing the sharp point mutation model can be divided into two situations: leading and lagging the first mutation time of infrared radiation. Taking the elastic energy release time as the standard, the infrared radiation mutation near the sandstone can be regarded as the precursor of sandstone failure. The results can provide a new idea for mine disaster monitoring and early warning.
Two adsorbents, magnesium aluminum calcined hydrotalcite (MgAl LDO) and magnesium aluminum iron calcined hydrotalcite (MgAlFe LDO), were synthesized by coprecipitation method, and characterized by X?ray powder diffraction (XRD) analysis, scanning electron microscopy (SEM) analysis, Fourier transform infrared spectroscopy (FT?IR) analysis and BET specific surface area test analysis, etc. The adsorption performance of the two adsorbents for fluoride in wastewater was also studied. The effects of the ratio of metal substances, calcination temperature, initial mass concentration of F-, and adsorbent dosage on the removal efficiency of fluoride in wastewater were investigated. The results showed that MgAlFe LDO had a uniform pore structure distribution, a large specific surface area, and a higher adsorption capacity for fluoride in wastewater than that of MgAl LDO. When n (Mg2+)/n (Al3+)/n (Fe3+)=3.0∶0.6∶0.4, the initial mass concentration of F- was 20 mg/L, the calcination temperature was 300 ℃, and the dosage of MgAlFe LDO was 0.4 g, the removal effect of fluoride in wastewater was optimal. After 2 hours of reaction, the removal rate of fluoride in the wastewater was 98.35%.
The effects of a single emulsifier octylphenol ethoxylate 10 (OP?10) and its compounding system on emulsion stability, rheology and the effect of organic bases on the interfacial tension were investigated. The results show that the optimal binary composition is as follows: The mass fraction of OP?10 is 1% and the mass fraction of sodium oleate (YSN) is 0.6%.The optimum compounding method can produce stable emulsion with thick oil, and the viscosity can be reduced from 1 168.22 mPa?s to 57.57 mPa?s, with the viscosity reduction rate of 91.03% and the water separation rate of 21.33%. The organobase triethanolamine (TEOA) can reduce the interfacial tension of the compounded system to the 10-2 mN/m level.
In order to explore the preparation process of graphene?reinforced composite materials with industrial development prospects, graphene/polypropylene composite materials were prepared using the melt blending method, and the graphene reinforcement mechanism was analyzed through experimental and computational analysis. The results indicate that through melt blending, graphene can be uniformly dispersed in the matrix. The tensile strength of the composite material with a graphene mass fraction of 0.5% is 50.3 MPa. When the mass fraction of graphene is 4.0%, the elastic modulus and tensile strength of the composites are increase by 77.1% and 22.5%, respectively, compared to the polypropylene matrix alone. The uniform dispersion of graphene and the interaction between graphene and the polypropylene matrix enable effective stress transfer at the graphene/polypropylene interface.
Hydrogen is regarded as a safe and sustainable supply of clean energy, which plays a very important role in alleviating the shortage of fossil energy and environmental pollution. Electrocatalytic water splitting is one of the effective ways to produce hydrogen. MoS2 has been widely used in electrocatalytic hydrogen evolution reaction because of its low Δ GH. This article summarizes the methods for improving the electrocatalytic hydrogen evolution performance of MoS2, including inducing phase transition or exposing more catalytic active sites in MoS2 through noble metal doping, and exposing more active sites or generating sulfur vacancies in MoS2 through transition metal and non?metal doping. Meanwhile, some suggestions have been put forward to improve the catalytic performance of MoS2.
As the global energy structure transitions toward cleaner and more sustainable sources, natural gas, as a low?carbon and environmentally friendly fossil fuel, continues to see increasing consumption. However, with the ongoing expansion of natural gas pipeline networks, the growing coverage areas, and the significant increases in both transportation distances and volumes, the safe operation of pipelines is facing unprecedented challenges, with pipeline leakage emerging as a particularly critical issue. In response to the long?term monitoring needs of oil and gas pipeline leaks, based on the principle of negative pressure wave detection, a highly efficient and reliable pipeline leakage monitoring simulation system was developed using LabVIEW, a powerful graphical programming platform. This system incorporates advanced sensor networks, data communication technologies, and signal processing algorithms. It was used for the leakage monitoring of oil and gas pipelines, and its performance was verified through experiments. The results show that the system is capable of detecting pipeline leakage and rapidly locating leakage points through efficient algorithms, providing crucial information for timely repair and ensuring the safety and stability of oil and gas pipelines.
In view of the huge scale of urban underground pipe network, the traditional manual detection method can no longer meet the needs of the current projects. In this paper, the MobileNetv3?YOLOv7 network model is proposed as the algorithm for target detection of underground pipeline defects to improve the accuracy and speed of detection. First, the pipeline image dataset is preprocessed, and the input image is grayscale and resampled to balance the number of samples. Secondly, the lightweight network MobileNetv3 and YOLOv7 network frameworks are combined to increase the BiFPN feature pyramid structure to improve accuracy. Then, in terms of data processing, Mosaic data augmentation is used to improve the robustness of the model. Finally, a comparative experiment with the YOLOv7 network model is designed to verify the feasibility of the model. In this paper, the MobileNetv3?YOLOv7 network model is verified under the framework of Pytorch experiment, and the experimental results show that the model greatly reduces the amount of parameter calculation and improves the average accuracy.
Carbon fiber reinforced epoxy resin matrix composites with light weight and high strength are widely used in aerospace, transportation, energy and other fields. The composition and structure of the interface are the main factors affecting the physical and chemical properties of composites. Surface modification of carbon fiber is one of the most effective ways to enhance the interfacial properties and mechanical properties of carbon fiber composites. In recent years, it's been found that porous materials with large specific surface area and diverse structures can improve the surface energy and surface roughness of carbon fibers and improve the interfacial properties of composites. This paper briefly introduces the modification of carbon fiber with different kinds of porous materials in recent years, and summarizes the interfacial strengthening effect of carbon fiber composites, which provides reference significance for the future research of porous materials reinforced carbon fiber composites.
In view of the influence of different factors on the leakage and diffusion of hydrogen?doped natural gas pipelines in the pipe gallery, the leakage and diffusion model of hydrogen?doped natural gas pipelines in the pipe gallery was established by numerical simulation software, and the influence of factors such as hydrogen doping ratio, pipeline pressure,leakage hole size and the model of ventilation on the gas diffusion process was studied. The results show that the hydrogen blending ratio can affect the mass transfer ability of hydrogen?doped natural gas, and the higher the hydrogen blending ratio, the faster the diffusion rate of hydrogen?doped natural gas. The pipeline pressure and leakage hole size mainly affect the leakage gas diffusion by affecting the initial kinetic energy and leakage volume of the leakage gas, and the leakage gas diffusion range becomes larger with the increase of pipeline pressure and leakage hole size. The ventilation mode plays a dominant role in the distribution of leaked gas in the pipe gallery, and the ventilation frequency is inversely proportional to the height of the leaked gas jet.