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Chinese Journal of Chemistry 2024年第2期42卷 157-163页

作者： Weicai Li Lu Tan Yijun Chen Rui Liu Zhongyu Qi Shixuan Yuan Zhanwen Huang Siping Wei Xi Du Dong Yi Nuclear Medicine and Molecular Imaging Key Laboratory of Sichuan Province School of PharmacySouthwest Medical UniversityLuzhouSichuan 646000China Department of Chemistry School of Basic Medical ScienceSouthwest Medical UniversityLuzhouSichuan 646000China Department of Pharmacy Affiliated HospitalSouthwest Medical UniversityLuzhouSichuan 646000China

Tetralin-1-carboxamides are frequently incorporated in myriad medicinally important ***,their existing synthetic routes not only suffer from some drawbacks such as tedious procedures,harsh reaction conditions,narrow substrate scope,low yields,and environmental problems,but are also based upon the elaboration of uneasily available non-linear tetralin ***,we describe a metal-and additive-free visible light-induced[4+2]annulation of two simple linear starting materials,namely acrylamides and 2-benzyl-2-bromocarbonyls,through a cascade C(sp^(3))-Br/C(sp^(2))-H bond cleavage,double C-C bond formation,and aromatization *** developed protocol provides a convenient,efficient,and green approach to a variety of tetralin-1-carboxamide derivatives with good functional group ***,the resulting products could also undergo the Licl-mediated mono-decarboxylative cyclization process to further furnish the architecturally novel bridged polycyclic imides with excellentcis-diastereoselectivities.

关键词： Annulation Metal-free Photoredox catalysis Tetralin-1-carboxamide Cyclic imides Synthetic methods C-C coupling Radical reactions Reaction mechanisms

Construction of ternary PEG200-based DESs lubrication systems via tailoring tribo-chemistry

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Friction 2024年第4期12卷 655-669页

作者： Yuting LI Songyu LAN Yazhou LIU Cheng CAO Zicheng TANG Deyin DENG Fuyuan LIU Hao LI Xiaoqiang FAN Minhao ZHU Key Laboratory of Advanced Technologies of Materials(Ministry of Education) School of Materials Science and EngineeringSouthwest Jiaotong UniversityChengdu 610031China Tribology Research Institute School of Mechanical EngineeringSouthwest Jiaotong UniversityChengdu 610031China

Designing novel lubricants with easily customized structures,devisable compositions,and simple and economic synthesis over traditional lubricants is critical to fulfilling complex applications,prolonging machine lifetime,and saving *** eutectic solvents(DESs),which show tunable composition,adjustable structure,easy fabrication,and environmental friendliness,are promising candidates for variable and complicated lubricants *** promote the use of DESs as lubricants,a series of PEG200-based DESs with active heteroatoms were fabricated to tailor the tribological performance via ***,PEG200/boric acid(BA)DES shows optimal lubrication performance by forming tribo-chemical reaction film composited of B2O3,iron oxides,and FeOOH,and PEG200/thiourea(TU)DES displays abrasive wear-reducing property by producing FeS tribo-chemical *** the excellent abrasive wear-resistance of PEG200/TU DES and friction reduction of PEG200/BA DES,ternary PEG200/BA/TU DESs,composited of PEG200/TU DES and PEG200/BA DES,are first *** ternary DESs possess superior wettability and thermal stability,which render them potential *** tests of the ternary DESs demonstrate that synergistic lubrication is achieved by forming a transfer film consisting of FexBy,BN,B2O3,and *** FexBy,BN,and B2O3 increase load bearing of the film,and FeS mitigates severe abrasive *** proposed design philosophy of novel DESs as lubricants opens up a unique realm that is unattainable by traditional DESs lubrication mechanisms and provides a platform to design next-generation DESs lubrication systems.

关键词： deep eutectic solvents(DESs) PEG200/boric acid DES PEG200/thiourea DES ternary DESs synergistic lubrication tribo-chemistry

Application status and research progress of CO2 fracturing fluid in petroleum engineering: A brief review

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Petroleum 2024年第1期10卷 1-10页

作者： Jinzhou Zhao Tong Wu Wanfen Pu Du Daijun Qingyuan Chen Bowen Chen Jintao Li Yitao Huang State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation Southwest Petroleum University Shale Gas Research Institute of PetroChina southwest Oil & Gas Field Company

This paper comprehensively reviews the application and research progress of CO2fracturing fluids in China, highlights the existing issues and puts forward suggestions for future development. Three types of fracturing fluid systems containing CO2, namely, CO2dry fracturing fluid, CO2energized fracturing fluid,and CO2foam fracturing fluid, are categorized based on the mass ratio and process difference between CO2, water, and treatment agents. Field applications in China reveal several problem to be resolved:（1）The application scope of CO2fracturing fluids is restricted to depleted reservoirs, re-fracturing of old wells, and medium-deep reservoirs with low formation pressure coefficients;（2） different types of CO2fracturing fluids require different processes and ground supporting equipment;（3） optimization of CO2compatibility, functionality, temperature and salt tolerance, as well as the cost of treatment agents is necessitated;（4） existing CO2fracturing fluid system fail to perform well with low friction, low filtration,and high sand-carrying capacity.（5） there lacks a targeted industry standard for evaluation of performance of CO2fracturing fluid system and treatment agents. Therefore, in order to meet the goals of CCUS-EOR, CCUS-EGR, or integration of fracturing, displacement and burial by CO2, efforts should be made in the aspects that followed, including in-depth investigation of the mechanism of CO2fracturing fluids, the adaptability and compatibility between existing equipment, different CO2fracturing fluid systems and processes, and construction of treatment agents, low-density proppants and highperformance systems of recyclability and industrial-grade. In addition, optimization of CO2fracturing fluid system based fracturing design is also crucial taking such related factors such as overall reservoir geological conditions, petrophysical properties, CO2transportation, and well site layout into consideration.

关键词： Reservoir reconstruction CO 2 fracturing fluid Fracturing fluid system Fracturing displacement burial integration

Effect of streamlined nose length on aerodynamic performance of high-speed train with a speed of 400 km/h

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Journal of Zhejiang university-Science A(Applied Physics & Engineering) 2024年第7期25卷 525-540页

作者： Nianxun LI Tian LI Zhiyuan DAI Deng QIN Jiye ZHANG State Key Laboratory of Rail Transit Vehicle System Southwest Jiaotong UniversityChengdu 610031China

The streamlined nose length(SNL)plays a crucial role in determining the aerodynamic performance of high-speed *** appropriate SNL can not only effectively reduce the magnitude of aerodynamic drag and lift forces,but also improve the performance of the high-speed train in tunnel passing and crosswind *** this study,a numerical simulation of the aerodynamic performance of high-speed trains at a speed of 400 km/h,with varying SNLs,is conducted using the k-ωshear stress transport(SST)turbulence *** different SNLs include 6.0,7.0,8.0,9.0,9.8,12.0,15.0,and 18.0 *** order to validate the accuracy of the numerical simulation,its results are compared with wind tunnel test data obtained from the *** simulation is carried out using compressible and incompressible gases to determine the effect of gas compressibility on *** impact of SNL on the aerodynamic performance of the trains is analyzed in terms of aerodynamic forces,velocity,and pressure *** comparison to the original train,the train with a 6.0 m SNL experienced a 10.8%increase in overall aerodynamic ***,the lift forces on the head and tail cars increased by 35.7%and 75.5%,*** the other hand,the train with an 18.0 m SNL exhibited a 16.5%decrease in aerodynamic ***,the lift forces on the head and tail cars decreased by 21.9%and 49.7%,*** aerodynamic drag force of the entire train varies linearly with the SNL,while the aerodynamic lift of the tail car follows a quadratic function in relation to the SNL.

关键词： Streamlined nose length(SNL) High-speed train Aerodynamic performance Numerical simulation Flow structures

Facile synthesis of nanoparticles-stacked Co_(3)O_(4)nanoflakes with catalase-like activity for accelerating wound healing

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Regenerative Biomaterials 2024年第3期3卷 82-91页

作者： Yanan Huang Wanyi Liao Wenxuan Wang Tingting Zhang Yan Zhang Lei Lu school and Hospital of Stomatology Wenzhou Medical UniversityWenzhou 325027China sichuan Engineering Research Center for Biomimetic Synthesis of Natural Drugs School of Life Science and EngineeringSouthwest jiaotong UniversityChengdu 610031China Key Lab of Advanced Technology of Materials of Education Ministry School of Materials Science and EngineeringSouthwest jiaotong UniversityChengdu 610031China school of Chemistry Southwest Jiaotong UniversityChengduSichuan 610031China

Delayed wound healing caused by excessive reactive oxygen species(Ros)remains a considerable *** recent years,metal oxide nanozymes have gained significant attention in biomedical ***,a comprehensive investigation of Co_(3)O_(4)-based nanozymes for enhancing wound healing and tissue regeneration is *** study focuses on developing a facile synthesis method to produce high-stability and costeffective Co_(3)O_(4)nanoflakes(NFs)with promising catalase(CAT)-like activity to regulate the oxidative microenvironment and accelerate wound *** closely arranged Co_(3)O_(4)nanoparticles(NPs)within the NFs structure result in a significantly larger surface area,thereby amplifying the enzymatic activity compared to commercially available Co_(3)O_(4)*** physiological conditions,itwas observed that CogO,NFs efficientlybreak down hydrogen peroxide(H_(2)O_(2))without generating harmful radicals(OH).Moreover,they exhibit excellent compatibility with various cells involved in wound healing,promoting fibroblast growth and protecting cells from oxidatives *** a ratmodel,Co_(3)O_(4) NFs facilitate both the hemostatic and proliferative phases of wound healing,consequently accelerating the ***,thepromising results of Co_(3)O_(4)NFs highlight their potential in promoting wound healing and tissue regeneration.

关键词： Co_(3)O_(4) nanoflake nanozyxygen species wound healing

Learning Epipolar Line Window Attention for Stereo Image Super-Resolution Reconstruction

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Computers, Materials & Continua 2024年第2期78卷 2847-2864页

作者： Xue Li Hongying Zhang Zixun Ye Xiaoru Huang School of Information Engineering Southwest University of Science and TechnologyMianyang621010China

Transformer-based stereo image super-resolution reconstruction(Stereo SR)methods have significantly improved image ***,existing methods have deficiencies in paying attention to detailed features and do not consider the offset of pixels along the epipolar lines in complementary views when integrating stereo *** address these challenges,this paper introduces a novel epipolar line window attention stereo image super-resolution network(EWASSR).For detail feature restoration,we design a feature extractor based on Transformer and convolutional neural network(CNN),which consists of(shifted)window-based self-attention((S)W-MSA)and feature distillation and enhancement blocks(FDEB).This combination effectively solves the problem of global image perception and local feature attention and captures more discriminative high-frequency features of the ***,to address the problem of offset of complementary pixels in stereo images,we propose an epipolar line window attention(EWA)mechanism,which divides windows along the epipolar direction to promote efficient matching of shifted pixels,even in pixel smooth *** accurate pixel matching can be achieved using adjacent pixels in the window as a *** experiments demonstrate that our EWASSR can reconstruct more realistic detailed *** quantitative results show that in the experimental results of our EWASSR on the Middlebury and Flickr1024 data sets for 2×SR,compared with the recent network,the Peak signal-to-noise ratio(PSNR)increased by 0.37 dB and 0.34 dB,respectively.

关键词： Stereo SR epipolar line window attention feature distillation

Influence of vibration on the lubrication effect of a splash-lubricated gearbox

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Journal of Zhejiang university-Science A(Applied Physics & Engineering) 2024年第4期25卷 324-339页

作者： Yi LIU Kailin ZHANG Shuai SHAO Hongxu XIANG Zhijian YE State Key Laboratory of Rail Transit Vehicle System Southwest Jiaotong UniversityChengdu 610031China

In this study,we investigate the effect of rail vibrations on the lubrication and efficiency of a splash-lubricated gearbox;specifically,the gearbox of a rail-transit vehicle.A high-fidelity 3D numerical model of the gearbox in a moving reference system is described,as well as computational fluid dynamics(CFD)simulations of the gearbox with different vibration *** effects of rotational speed,oil-immersion depth,and different oil-injection volume rates on lubrication and efficiency are *** propose a method of evaluating the internal lubrication condition of a splash-lubricated gearbox and quantitatively compare the effects of different operating parameters on lubrication and ***,our experiment to verify the feasibility of the simulation method is *** results show that with vibration,the churning loss and oil supply for the bearings are significantly higher than those under static *** addition,among different vibrational directions,lateral vibration has the greatest influence on the lubrication condition and efficiency of the *** the studied railway-vehicle gearbox,the best lubrication condition is achieved at a rotational speed of 1600 r/min and an oil-immersion depth of two times the tooth height(***).Rotational speed is the operating parameter that has the most significant effect on the lubrication and efficiencyofthegearbox.

关键词： Comprehensive lubrication evaluation Churning loss Moving reference system Splash lubrication Vibrational excitation Gearbox

Dynamics modeling and electromechanical coupling characteristics analysis of cage induction motors

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Science China(Technological Sciences) 2024年第3期67卷 709-724页

作者： ZHOU ZiWei CHEN ZaiGang ZHAI WanMing State Key Laboratory of Rail Transit Vehicle System Southwest Jiaotong UniversityChengdu 610031China

Induction motors, as typical electromechanical energy conversion devices, have received limited attention in previous studies on electromechanical coupling vibrations, precise modeling, and the use of electromechanical coupling effects for fault diagnosis and condition assessment in motor drive systems. This study proposes a comprehensive model of cage induction motors that integrates the multiple coupled circuit model with a rotor-bearing dynamics model. The model accounts for the linear increase in the magnetomotive force across the slot and incorporates the skidding characteristics of bearings in the rotor-bearing system. By calculating the time-varying mutual inductance parameters based on the air-gap distribution in the vibration environment, the electromechanical coupling vibration of the cage motor is investigated. Furthermore, this study examines the electromechanical coupling vibration characteristics influenced by various factors, including bearing clearances, radial loads, and the vertical excitation frequencies of the stators. The results show that the proposed model improves the excitation inputs for the electrical and mechanical systems of the motor compared with conventional models. Increased bearing clearance and radial load affect the current and torque similarly but have opposite effects on the slip ratio. This study provides a deeper understanding of electromechanical coupling mechanisms and facilitates the use of such phenomena for fault diagnosis and condition assessment in motor-driven systems.

关键词： cage induction motors rotor-bearing dynamics mutual inductance electromechanical testing current signal analysis

Visibility restoration for real-world hazy images via improved physical model and Gaussian total variation

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Frontiers of Computer Science 2024年第1期18卷 267-269页

作者： Chuan LI Enping HU Xinyu ZHANG Hao ZHOU Hailing XIONG Yun LIU College of Computer and Information Science Southwest UniversityChongqing 400715China School of Big Data and Intelligent Engineering Chongqing College of International Business and EconomicsChongqing 401520China College of Artificial Intelligence Southwest UniversityChongqing 400715China College of Electronic and Information Engineering Southwest UniversityChongqing 400715China

1 Introduction Under real-world haze conditions,the existence of haze particles in the atmosphere reduces the visibility of captured ***,the noise is inevitably introduced into the degraded image,which further deteriorates the visual quality of the *** enhance the visibility and quality of outdoor real-world hazy images,numerous algorithms have been proposed to remove haze from a single input *** existing methods are broadly lumped into two categories:prior-based methods[1,2]and learning-based methods[3–6].Unfortunately,the widely used atmospheric scattering model and the corresponding haze removal methods fail to take the noise interference into account,which may result in poor visibility restoration performance.

关键词： visibility remove noise

ANovel Non-Isolated Cubic DC-DC Converter with High Voltage Gain for Renewable Energy Power Generation System

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Energy Engineering 2024年第1期121卷 221-241页

作者： Qin Yao Yida Zeng Qingui Jia School of Electrical Engineering Southwest Jiaotong UniversityChengdu610036China

In recent years,switched inductor(SL)technology,switched capacitor(SC)technology,and switched inductor-capacitor(SL-SC)technology have been widely applied to optimize and improve DC-DC boost converters,which can effectively enhance voltage gain and reduce device *** address the issue of low output voltage in current renewable energy power generation systems,this study proposes a novel non-isolated cubic high-gain DC-DC converter based on the traditional quadratic DC-DC boost converter by incorporating a SC and a SL-SC ***,the proposed converter’s details are elaborated,including its topology structure,operating mode,voltage gain,device stress,and power ***,a comparative analysis is conducted on the voltage gain and device stress between the proposed converter and other high-gain ***,a closed-loop simulation system is constructed to obtain simulation waveforms of various devices and explore the dynamic ***,an experimental prototype is built,experimental waveforms are obtained,and the experimental dynamic performance and conversion efficiency are *** theoretical analysis’s correctness is verified through simulation and experimental *** proposed converter has advantages such as high voltage gain,low device stress,high conversion efficiency,simple control,and wide input voltage range,achieving a good balance between voltage gain,device stress,and power *** proposed converter is well-suited for renewable energy systems and holds theoretical significance and practical value in renewable energy *** provides an effective solution to the issue of low output voltage in renewable energy power generation systems.

关键词： Cubic DC-DC converter high voltage gain low device stress high efficiency renewable energy