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COMPOSITE ElEMENT METHOD FOR SEEPAGE ANAlYSIS OF GEOTECHNICAl STRUCTURES WITH DRAINAGE HOlE ARRAY

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Journal of Hydrodynamics 2004年第3期16卷 260-266页

作者： CHENSheng-hong xuqing HUJing StateKeylaboratoryofWaterResourcesandHydropowerEngineeringScience WuhanUniversityWuhan430072 CollegeofEnvironmentScienceandEngineering HohaiUniversityNanjing210098China SchoolofWaterResourcesandHydropower WuhanUniversityWuhan430072China

Air element concept and Composite Element Method (CEM) were introduced inthis paper firstly, and then an explicit drainage holes element model was developed. The mainadvantage of the new model is that it allows drainage holes to be located within soil *** the mesh generation of complicated geotechnical structures with a large number of seepagedrainage holes becomes relatively convenient and feasible. This will further facilitate the optimaldesign of seepage control system, and in this case the calculation mesh can be kept unchanged whenthe number, position and orientation of drainage holes are adjusted. The model was been implementedin software. A sluice foundation seepage control problem was studied, by which the validity and therobustness of the new model were verified.

关键词： seepage drainage hole air element composite element geotechnicalengineering

Molecular tailoring to improve polypyrrole hydrogels7 stiffness and electrochemical energy storage capacity

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Frontiers of Chemical Science and Engineering 2019年第4期13卷 684-694页

作者： Evelyn Chalmers Yi li xuqing liu School of Materials The University of ManchesterManchester M139PLUK

This research looks at ways of tailoring and improving the stiffness of polypyrrole hydrogels for use as flexible supercapacitor *** providing additional cross-linking between polypyrrole chains are added post-polymerisation but before gelation,and are found to increase gel stiffness by up to 600%,with the degree of change dependent on reactant type and *** was also found that addition of phytic acid led to an increase in pseudocapacitive behaviour o f the hydrogel,and thus a maximum specific capacitance of 217.07 F·g^-1 could be *** is an increase of 140%compared to pristine polypyrrole hydrogels produced by this method.

关键词： supercapacitor polypyrrole hydrogel strengthening electrochemical

THE NONCONFORMING CROUZEIX-RAVIART ElEMENT APPROXIMATION AND TWO-GRID DISCRETIZATIONS FOR THE ElASTICEIGENVAlUE PROBlEM

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Journal of Computational Mathematics 2023年第6期41卷 1041-1063页

作者： Hai Bi xuqing Zhang Yidu Yang School of Mathematical Sciences Guizhou Normal UniversityGuiyang 550025China School of Biology&Engineering Guizhou Medical UniversityGuiYang 550025China

In this paper,we extend the work of Brenner and Sung[***.59,321–338(1992)]and present a regularity estimate for the elastic equations in concave *** on the regularity estimate we prove that the constants in the error estimates of the nonconforming Crouzeix-Raviart element approximations for the elastic equations/eigenvalue problem are independent of laméconstant,which means the nonconforming Crouzeix-Raviart element approximations are *** also establish two kinds of two-grid discretization schemes for the elastic eigenvalue problem,and analyze that when the mesh sizes of coarse grid and fine grid satisfy some relationship,the resulting solutions can achieve the optimal *** examples are provided to show the efficiency of two-grid schemes for the elastic eigenvalue problem.

关键词： Elastic eigenvalue problem Nonconforming Crouzeix-Raviart element Two-grid discretizations Error estimates locking-free

Performance Evaluation on the In-Cylinder Heat Transfer of a Reciprocating Compressor using CO_(2) as a Working Fluid

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Journal of Thermal Science 2022年第5期31卷 1518-1530页

作者： lIU Zhan YANG xuqing YANG Xiaohu ZHAI Hongyan DUAN Zhenya College of Electromechanical Engineering Qingdao University of Science and TechnologyQingdao266061China School of Human Settlements and Civil Engineering Xi’an Jiaotong UniversityXi’an710049China

The aim of this current work is to investigate the effects of operating parameters on heat transfer characteristics between gas and in-cylinder solid surfaces in a reciprocating compressor.A numerical model has been implemented in MATlAB based on mass balance,the first law of thermodynamics,and NIST REFPROP database for gas properties and thermodynamic *** impacts of key parameters such as rotational speed,suction temperature,pressure ratio and suction pressure are particularly evaluated on heat transfer coefficient(HTC),heat flux(HF)and gas *** demonstrate that HTC increases markedly with the increase of rotational speed,pressure ratio and suction pressure,and decreases slightly with the increase of suction temperature;the instantaneous HF strengthens significantly with the increase of rotational speed,pressure ratio and suction pressure,whereas the mean HF magnitude transferred from gas to the wall decreases with the increase of rotational speed;the maximum gas temperature is more sensitive to suction temperature and pressure ratio.

关键词： heat transfer coefficient heat flux reciprocating compressor parametric study

Advanced Fiber Materials for Wearable Electronics

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Advanced Fiber Materials 2023年第1期5卷 12-35页

作者： Chuang Zhu Jiawei Wu Jianhua Yan xuqing liu Department of Materials School of Natural SciencesUniversity of ManchesterOxford RdManchester M139PLUK Key laboratory of Textile Science&Technology Ministry of EducationCollege of TextilesDonghua UniversityShanghai 201620People’s Republic of China

Fiber materials are highly desirable for wearable electronics that are expected to be flexible and *** with rigid and planar electronic devices,fiber-based wearable electronics provide significant advantages in terms of flexibility,stretchability and breathability,and they are considered as the pioneers in the new generation of soft *** con-vergence of textile science,electronic engineering and nanotechnology has made it feasible to build electronic functions on fibers and maintain them during *** the last few years,fiber-shaped wearable electronics with desired designability and integration features have been intensively explored and *** an indispensable part and cornerstone of flexible wearable devices,fibers are of great ***,the research progress of advanced fiber materials is reviewed,which mainly includes various material preparations,fabrication technologies and representative studies on different wearable ***,key challenges and future directions of fiber materials and wearable electronics are examined along with an analysis of possible solutions.

关键词： Conductive fibers Piezoelectric fibers Sensors Artificial muscles Energy harvesting and storage

Effective sugar-derived organic gelator for three different types of lubricant oils to improve tribological performance

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Friction 2020年第6期8卷 1025-1038页

作者： Ruochong ZHANG xuqing lIU Zhiguang GUO Meirong CAI lei SHI State Key laboratory of Solid lubrication Lanzhou Institute of Chemical PhysicsChinese Academy of SciencesLanzhou 730000China University of Chinese Academy of Sciences Beijing 100049China School of Materials University of ManchesterOxford RoadManchester M139PLUK Hubei Collaborative Innovation Centre for Advanced Organic Chemical Materials and Key laboratory for the Green Preparation and Application of Functional Materials(Ministry of Education) Hubei UniversityWuhan 430062China

In this study,the gelling ability and lubrication performance of N-octadecyl-D-gluconamides(NOG)in liquid paraffin(lP),pentaerythritol oleate(PE-OA),and polyethylene glycol(PEG)oils were systemically *** NOG,which could gelate the investigated oils,was successfully synthesized by a one-step *** prepared gel lubricants were completely thermoreversible and exhibited improved thermal stability,according to the thermogravimetry analysis(TGA)*** tests confirmed that the NOG gelator could effectively regulate the rheological behavior of the base *** evaluation suggested that NOG,as an additive in the three types of base oils,could remarkably reduce the friction and wear in steel contacts.A plausible mechanism for the improved performances was proposed based on the mechanical strength of the gels and the formation of the boundary-lubricating film on the worn *** results indicated that NOG is a potential gelator for preparing gel lubricants with excellent tribological properties and environment-friendly characteristics.

关键词： gel lubricant supermolecular assembly rheological property tribological performance lubricating mechanism

A New Method for Preparation and Characterization of lipo-alkaloid

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Chemical Research in Chinese Universities 2004年第1期20卷 121-123页

作者： WANGYong xuqing-xuan SONGFeng-rui lIUZhi-qiang lIUShu-ying TheNewDruglaboratory ChangchunInstituteofAppliedChemistryChineseAcademyofSciencesChangchun130022P.R.China

A simple route for the preparation of lipo-alkaloid is presented. When aconitine or one of its analogues is heated with a fatty acid for 20 min at 100 ℃ in water, the C_8 acetyl group of aconitine is displaced by a long chain fatty acyl group. The structures of the products were characterized by electrospray ionization tandem mass spectrometry.

关键词： Aconitine lipo-alkaloid Electrospray ionization tandem mass spectrometry

Influence of γ' precipitate on deformation and fracture during creep in PM nickel-based superalloy

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Progress in Natural Science:Materials International 2021年第2期31卷 303-309页

作者： Zichao Peng Jinwen Zou Jie Yang Gaofeng Tian xuqing Wang Science and Technology on Advanced High Temperature Structural Materials laboratory Beijing Institute of Aeronautical MaterialsAECC

FGH96 is a powder metallurgy nickel based superally used for turbine disk of aero-engines. In the present study FGH96 alloy with four different γ' precipitate microstructures were produced via solution heat-treatment with different cooling rates, and the maximum cooling rate reached 400°C/min which was a super cooling rate for Nickel-based superalloy. The creep tests were conducted for PM FGH96 alloy under the testing condition of 704°C and 690 MPa. The relationship between the creep properties and the distribution of γ' precipitate was established. The creep mechanism was analyzed by using TEM and ACTEM, and the dislocation movement was studied at the atomic scale. The creep strain rate was calculated through a physically based crystal slip model established based on crystal plasticity. The calculated results were consistent with the test ones, illustrating the validity of the model. The fracture mechanism was also investigated, and the results showed that the creep cracks generated on the surface due to the oxidation. It was observed that the cracks propagated in different ways depending on the different average diameters of γ' precipitate. With the decrease of the average γ' precipitate size,the critical shearing stress increased and the resistance of the dislocation slipping increased. The fracture mechanism for the primary stage transformed from intragranular to intergranular due to the change of dislocation slipping.

关键词： PM FGH96 superalloy Microtwinning γ′ precipitate Fracture mechanism Physically-based creep model

Ultrahigh energy storage with superfast charge-discharge capability achieved in linear dielectric ceramic

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Journal of Materials Science & Technology 2024年第10期177卷 59-67页

作者： xuqing Zhang Yongping Pu Yating Ning lei Zhang Bo Wang Zhemin Chen School of Materials Science and Engineering Shaanxi University of Science&TechnologyXi'an 710021China

Ceramic capacitors designed for energy storage demand both high energy density and ***-ing a high breakdown strength based on linear dielectrics is of utmost *** this study,we present the remarkable performance of densely sintered(1-x)(Ca_(0.5)Sr_(0.5)TiO_(3))-xBa_(4)Sm_(28)/3Ti_(18)O_(54) ceramics as energy storage materials,with a measured energy density(Wrec)of 4.9 J/cm^(3)and an ultra-high ef-ficiency(η)of 95%which is almost optimal in linear dielectric that has been *** unravel the underlying mechanisms,we conducted a systematic investigation on the influence of adding paraelec-tric Ba_(4)Sm_(28/3)Ti_(18)O_(54)(BST)on both microstructure and macroscopic electrical properties of Ca_(0.5)Sr_(0.5)TiO_(3)(CST).Notably,the addition of BST effectively reduces the grain size of *** conduction mechanism is primarily governed by grain boundaries,where high-density grain boundaries act as barriers to charge carrier transport due to their elevated ***,the activation energy associated with grain boundaries increases with rising resistivity,implying a lower concentration of free vacancies within these *** increased barrier height for oxygen vacancy migration at grain boundaries compensates for the grain boundary defects,thereby resulting in enhanced breakdown *** characteristic offers a substantial advantage in terms of thermal and frequency stability(25-175℃,1-100 Hz).This work introduces a candidate material with outstanding comprehensive energy storage properties.

关键词： linear dielectric ceramic Ca_(0.5)Sr_(0.5)TiO_(3) Energy storage Grain boundary