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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2017年第8期18卷 631-647页

作者： Xin-biao xiao Ya-guang LI Ting-sheng ZHONG xiao-zhen sheng State Key Laboratory of Traction Power Southwest Jiaotong University Chengdu 610031 China

Installation of rail vibration dampers （rail dampers for short） onto rails between sleepers is one of the measures to control rail noise generation and roughness growth. Amid the rapid expansion of high-speed and underground railway networks in China, many suppliers are actively marketing and promoting their products, often giving confusing information. In this paper, a parametric study is used to investigate the effect of rail dampers on the dynamical behavior of a Chinese high-speed railway track. The Fourier transform-based method developed for analyzing dynamics of a railway track as an infinitely long periodic structure, with or without rail dampers, is applied in the investigation. It is hoped that results in this paper can help develop the understanding of the working mechanism of rail dampers, and provide useful information for product design and application.

关键词： Rail damper Track dynamics Dispersion curves Vibration decay rate

Study on the subgrade deformation under high-speed train loading and water–soil interaction

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Acta Mechanica Sinica 2016年第2期32卷 233-243页

作者： Jian Han Guo-Tang Zhao xiao-zhen sheng Xue-Song Jin State Key Laboratory of Traction Power Southwest Jiaotong University Chengdu 610031 China China Railway Corporation Beijing 100844 China

It is important to study the subgrade characteristics of high-speed railways in consideration of the water–soil coupling dynamic problem,especially when high-speed trains operate in rainy *** study develops a nonlinear water–soil interaction dynamic model of slab track coupling with subgrade under high-speed train loading based on vehicle–track coupling *** using this model,the basic dynamic characteristics,including water–soil interaction and without water induced by the high-speed train loading,are *** main factors-the permeability coefficien and the porosity-influencin the subgrade deformation are *** developed model can characterize the soil dynamic behaviour more realistically,especially when considering the influenc of water-rich soil.

关键词： Water–soil interaction High-speed train loading Finite difference method Subgrade deformation Permeability coefficien Porosity

Characteristics of interior noise of a Chinese high-speed train under a variety of conditions

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2017年第8期18卷 617-630页

作者： Jie ZHANG Xin-biao xiao xiao-zhen sheng Rong FU Dan YAO Xue-song JIN State Key Laboratory of Traction Power Southwest Jiaotong University Chengdu 610031 China

This paper presents an investigation into the characteristics of interior noise of a Chinese high-speed train under several typical conditions. Interior noises within Vehicle TC01, which can be used as a head car or an end car, and Vehicle TP03, the third car counting from TC01, are measured for the train running at speeds from 260 km/h to 385 km/h, along two types of track including a slab track and a ballast track and either on the ground surface or in a tunnel. Data analyses are performed for sound pressure overall levels, frequency, area contributions, and possible generation mechanisms, showing how they are affected by train speed, running direction, track type, and tunnel. The results show that, whether TC01 is used as head car or end car, the interior noise characteristics in the VIP cabin are mostly related to aerodynamic noise. Differences in interior noise between tracks become smaller as the train speed increases. The effect of a tunnel on the interior noise is more important for the middle coach than that for the head coach. This study can provide a basis for noise control of high-speed trains.

关键词： High-speed train Interior noise Noise source identification Contribution analysis Various conditions Noise characterization

Intermolecular Acid-Base-Pairs Containing Poly(p-Terphenyl-co-Isatin Piperidinium) for High Temperature Proton Exchange Membrane Fuel Cells

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Energy & Environmental Materials 2024年第3期7卷 410-418页

How to optimize and regulate the distribution of phosphoric acid in matrix,and pursuing the improved electrochemical performance and service lifetime of high temperature proton exchange membrane （HT-PEMs） fuel cell are significant ***,bifunctional poly （p-terphenyl-co-isatin piperidinium） copolymer with tethered phosphonic acid （t-PA） and intrinsic tertiary amine base groups are firstly prepared and investigated as *** distinctive architecture of the copolymer provides a well-designed platform for rapid proton *** not only transports through the hydrogen bond network formed by the adsorbed free phosphoric acid （f-PA）anchored by the tertiary amine base groups,but also rely upon the proton channel constructed by the ionic cluster formed by the t-PA *** the design of the structure,the bifunctional copolymers with lower PA uptake level （<100%） display prominent proton conductivities and peak power densities (99 mS cm-1,812 mW cm-2at 160℃),along with lower PA leaching and higher voltage stability,which is a top leading result in disclosed *** results demonstrate that the design of intermolecular acid-base-pairs can improve the proton conductivity without sacrificing the intrinsic chemical stability or mechanical property of the thin membrane,realizing win-win demands between the mechanical robustness and electrochemical properties of HT-PEMs.

关键词： bifunctional copolymer high temperature proton exchange membrane intermolecular acid–base-pairs phosphonic acid retention phosphonic acid uptake level

Polymer-to-Monomers Chemically Recyclable Poly(imide-imine)Plastics with Extreme-Condition Resistance and Flame Retardancy

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Chinese Journal of Polymer Science 2024年第10期42卷 1525-1535页

作者： zhen-Yu Wang xiao-Kong Liu State Key Laboratory of Supramolecular Structure and Materials College of ChemistryJilin University

Polyimides are a family of high-tech plastics that have irreplaceable applications in the fields of aerospace, defense, and opto-electronics, but polyimides are difficult to be reprocessed and recycled at the end of their service life, resulting in a significant waste of resources. Hence, it is of great significance to develop recyclable polyimides with comparable properties to the commercial products. Herein, we report a novel polymer-to-monomers chemically recyclable poly(imide-imine)(PtM-CR-PII) plastic, synthesized by cross-linking the amine-terminated aromatic bisimide monomer and the hexa-vanillin terminated cyclophosphazene monomer via dynamic imine bonds. The PtM-CR-PII plastic exhibits comparable mechanical and thermal properties as well as chemical stability to the commercial polyimides. The PtM-CR-PII plastic possesses a high Young’s modulus of≈3.2 GPa and a tensile strength as high as≈108 MPa, which also exhibits high thermal stability with a glass transition temperature of≈220°C. Moreover, the PtM-CR-PII plastic exhibits outstanding waterproofness, acid/alkali-resistance, and solvent-resistance, its appearance and mechanical properties can be well maintained after long-term soaking in water, highly concentrated acid and base, and various organic solvents. Furthermore, the cyclophosphazene moieties endow the PtM-CR-PII plastic with excellent flame retardancy. The PtM-CR-PII plastic exhibits the highest UL-94 flame-retarding rating of V-0 and a limiting oxygen index (LOI) value of 45.5%. Importantly, the PtM-CR-PII plastic can be depolymerized in an organic solvents-acid mixture medium at room temperature, allowing easy separation and recovery of both monomers in high purity. The recovered pure monomers can be used to regenerate new PtM-CR-PII plastics, enabling sustainable polymer-monomers-polymer circulation.

关键词： Chemical recyclability Chemical stability Dynamic imine bonds Mechanical properties Polyimides Polyimines

Infinitely Many Solutions for a Class of Quasi-linear Elliptic Problem

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Acta Mathematicae Applicatae Sinica 2024年第3期40卷 728-743页

作者： xiao-yao JIA zhen-luo LOU School of Economics and Management Zhongyuan University of TechnologyZhengzhou 450007China Mathematics and Statistics School Henan University of Science and TechnologyLuoyang 471023China

In this paper,we study the following quasi-linear elliptic equation:■where Ω?R^(N) is a bounded domain,λ>0 is a *** function ψ(|t|)t is the subcritical term,and φ(|t|)t is the critical Orlicz-Sobolev growth term with respect to φ.Under appropriate conditions on φ,ψ and φ,we prove the existence of infinitely many weak solutions for quasi-linear elliptic equation,for λ∈(0,λ_(0)),where λ_(0)> 0 is a fixed constant.

关键词： quasi-linear elliptic equations variational methods Orlicz-Sobolev spaces

Intermolecular Acid-Base-Pairs Containing Poly(p-Terphenyl-co-lsatin Piperidinium)for High Temperature Proton Exchange Membrane Fuel Cells

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能源与环境材料（英文） 2024年第3期7卷 406-414页

作者： xiaofeng Hao zhen Li Min xiao Zhiheng Huang Dongmei Han sheng Huang Wei Liu Shuanjin Wang Yuezhong Meng The Key Laboratory of Low-carbon Chemistry & Energy Conservation of Guangdong Province State Key Laboratory of Optoelectronic Materials and TechnologiesSchool of Materials Science and EngineeringSun Yat-sen UniversityGuangzhou 510275China The Key Laboratory of Low-carbon Chemistry & Energy Conservation of Guangdong Province State Key Laboratory of Optoelectronic Materials and TechnologiesSchool of Materials Science and EngineeringSun Yat-sen UniversityGuangzhou 510275China School of Chemical Engineering and Technology Sun Yat-sen UniversityZhuhai 519000China The Key Laboratory of Low-carbon Chemistry & Energy Conservation of Guangdong Province State Key Laboratory of Optoelectronic Materials and TechnologiesSchool of Materials Science and EngineeringSun Yat-sen UniversityGuangzhou 510275China School of Chemical Engineering and Technology Sun Yat-sen UniversityZhuhai 519000China Institute of Chemistry Henan Provincial Academy of SciencesZhengzhou 450000China·Research Center of Green CatalystsCollege of ChemistryZhengzhou UniversityZhengzhou 450001China

How to optimize and regulate the distribution of phosphoric acid in matrix,and pursuing the improved electrochemical performance and service lifetime of high temperature proton exchange membrane(HT-PEMs)fuel cell are significant ***,bifunctional poly(p-terphenyl-co-isatin piperidinium)copolymer with tethered phosphonic acid(t-PA)and intrinsic tertiary amine base groups are firstly prepared and investigated as *** distinctive architecture of the copolymer provides a well-designed platform for rapid proton *** not only transports through the hydrogen bond network formed by the adsorbed free phosphoric acid(f-PA)anchored by the tertiary amine base groups,but also rely upon the proton channel constructed by the ionic cluster formed by the t-PA *** the design of the structure,the bifunctional copolymers with lower PA uptake level(＜100％)display prominent proton conductivities and peak power densities(99 mS cm-1,812 mW cm-2 at 160 ℃),along with lower PA leaching and higher voltage stability,which is a top leading result in disclosed *** results demonstrate that the design of intermolecular acid-base-pairs can improve the proton conductivity without sacrificing the intrinsic chemical stability or mechanical property of the thin membrane,realizing win-win demands between the mechanical robustness and electrochemical properties of HT-PEMs.

关键词： bifunctional copolymer high temperature proton exchange membrane intermolecular acid-base-pairs phosphonic acid retention phosphonic acid uptake level

Limits of Riemann Solutions for Isentropic MHD in a Variable Cross-Section Duct as Magnetic Field Vanishes

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Chinese Annals of Mathematics,Series B 2024年第4期45卷 637-660页

作者： Wancheng sheng Tao xiao Department of Mathematics Shanghai University Shanghai Aircraft Design and Research Institute

The stability for magnetic field to the solution of the Riemann problem for the polytropic fluid in a variable cross-section duct is discussed. By the vanishing magnetic field method, the stable solutions are determined by comparing the limit solutions with the solutions of the Riemann problem for the polytropic fluid in a duct obtained by the entropy rate admissibility criterion.

关键词： 35L50 35L65 35L80 76J20 76N10 Magnetogasdynamics Riemann problem Stability Vanishing magnetic field method Variable duct

Molecular Chaperone-Dependent Polymer Translocation through Nanopores: The Effects of Chaperone Concentration and Chaperone-Polymer Interaction

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Chinese Journal of Polymer Science 2024年第1期42卷 125-132,I0011页

作者： Chang-sheng Zuo Kang Wang Li-zhen Sun Ting-Ting Sun Department of Physics Zhejiang University of Science and TechnologyHangzhou 310023China Department of Applied Physics Zhejiang University of TechnologyHangzhou 310014China

The polymer translocation through a nanopore from a donor space(or named cis side) to a receiver space(trans side) in the chaperone-induced crowded environment has attracted increasing attention in recent years due to its significance in biological systems and technological applications. In this work, we mainly focus on the effects of chaperone concentration and chaperone-polymer interaction on the polymer translocation. By assuming the polymer translocation to be a quasi-equilibrium process, the free energy F of the polymer can be estimated by Rosenbluth-Rosenbluth method and then the translocation time τ can be calculated by Fokker-Plank equation based on the obtained free energy landscape. Our calculation results show that the translocation time can be controlled by independently tuning the chaperone concentration and chaperone-polymer interaction at the cis side or the trans side. There exists a critical chaperone-polymer attraction ε~*=-0.2 at which the volume exclusion and interaction effects of the chaperone can balance each other. Additionally, we also find that at large chaperone-polymer attraction, the translocation time is mainly governed by the diffusion coefficient of the polymer.

关键词： Polymer translocation Rosenbluth-Rosenbluth method Fokker-Plank equation Free energy landscapes

Revisiting the island of hexadecapoledeformation nuclei in the A≈150 mass region:focusing on the model application to nuclear shapes and masses

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Communications in Theoretical Physics 2024年第2期76卷 74-88页

作者： xiao-Yang Wei Hua-Lei Wang zhen-zhen Zhang Min-Liang Liu School of Physics and Microelectronics Zhengzhou UniversityZhengzhou 450001China Key Laboratory of High Precision Nuclear Spectroscopy Institute of Modern PhysicsChinese Academy of SciencesLanzhou 730000China School of Nuclear Science and Technology University of Chinese Academy of SciencesBeijing 100049China

Based on the potential-energy-surface calculation,the impact of different deformation degrees of freedom on a single-particle structure and binding energies in nuclei around^(152)Nd,located on one of the hexadecapole-deformation islands,is analyzed in a multi-dimensional deformation *** energy maps,curves and tables are presented to indicate nuclear *** calculated equilibrium deformations and binding energies with different potential parameters are compared with experimental data and other *** is found that the inclusion of the hexadecapole deformations,especially the axial one,can improve the theoretical description of both nuclear shapes and *** addition,our calculated potential-energy curve shows that a critical deformation-point,β_(2)≈0.4,exists—the triaxial(hexadecapole)deformation effect can be neglectable but the hexadecapole(triaxial)one plays an important role before(after)such a critical point.

关键词： hexadecapole deformation binding energy potential-energy-surface calculation nuclear property