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Lightweight, highly tough and durable YBa2Cu3O7-x superconductor

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National Science Review 2023年第3期10卷 9-16页

作者： Baoqiang Zhang Xingyi Zhang you-he zhou Key Laboratory of Mechanics on Disaster and Environment in Western China attached to the Ministry of Education of China Lanzhou University Department of Mechanics and Engineering Sciences College of Civil Engineering and Mechanics Lanzhou University

The inherent brittleness and low sustainability of YBa2Cu3O7-x(YBCO) bulk superconductor seriously impede its wide *** is a great challenge to achieve toughening of this material and maintain its invariable superconductivity at the same ***,we fabricate bulk YBCO composite superconductor with a density of 2.15 g cm-3,which consists of interlocking dual network construction and shows high toughness and *** results show that its unit normalized fracture energy at 77 K reaches638.6 kN m-2,which is～14.8 times that of YBCO bulk prepared by the top-seeded melt textured growth(TSMTG) *** critical current shows no degradation during the toughening ***,after 10 000 cycles,the sample does not fracture with the decay of critical current at 4 K of 14.6% whereas the TSMTG sample fractures only after 25 cycles.

关键词： YBCO superconductor lightweight toughness durability interlocking dual network

Theoretical analysis for the mechanical behavior caused by an electromagnetic cycle in ITER Nb3Sn cable-in-conduit conductors

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Acta Mechanica Sinica 2018年第4期34卷 614-622页

作者： Donghua Yue Xingyi Zhang you-he zhou Department of Mechanics and Engineering Sciences College of Civil Engineering and MechanicsLanzhou UniversityLanzhou 730000China Key Laboratory of Mechanicson Disaster and Environmentin Western China attached to the Ministry of Education of China Lanzhou 730000China

The central solenoid（CS）is one of the key components of the International Thermonuclear Experimental Reactor（ITER）tokamak and which is often considered as the heart of this fusion *** solenoid will be built by using Nb3Sn cablein-conduit conductors（CICC）,capable of generating a 13 T magnetic *** order to assess the performance of the Nb3Sn CICC in nearly the ITER condition,many short samples have been evaluated at the SULTAN test facility（the background magnetic field is of 10.85 T with the uniform length of 400 mm at 1%homogeneity）in Centre de Recherches en Physique des Plasma（CRPP）.It is found that the samples with pseudo-long twist pitch（including baseline specimens）show a significant degradation in the current-sharing temperature（Tcs）,while the qualification tests of all short twist pitch（STP）samples,which show no degradation versus electromagnetic cycling,even exhibits an increase of *** behavior was perfectly reproduced in the coil experiments at the central solenoid model coil（CSMC）facility last *** this paper,the complex structure of the Nb3Sn CICC would be simplified into a wire rope consisting of six petals and a cooling *** analytical formula for the Tcs behavior as a function of the axial strain of the cable is *** on this,the effects of twist pitch,axial and transverse stiffness,thermal mismatch,cycling number,magnetic distribution,etc.,on the axial strain are discussed *** calculated Tcs behavior with cycle number show consistency with the previous experimental results qualitatively and ***,we focus on the relationship between Tcs and axial strain of the cable,and we conclude that the Tcs behavior caused by electromagnetic cycles is determined by the cable axial *** the cable is in a compression situation,this compression strain and its accumulation would lead to the Tcs *** experimental observation of the Tcs enhancement in the CS STP samples should be consid

关键词： Mechanical behavior Nb3Sn cable in conduit conductor Electromagneti ccycle Sharing temperature

Extraction on the Contact Forces Among the Opaque and Non-photoelastic Particles Under Electromagnetic Force

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Acta Mechanica Solida Sinica 2022年第2期35卷 248-260页

作者： Shuaike Jiao Cong Liu Jun zhou Xingyi Zhang you-he zhou Key Laboratory of Mechanics on Disaster and Environment in Western China Attached to the Ministry of Education of China Lanzhou UniversityLanzhou 730000China Department of Mechanics and Engineering Sciences College of Civil Engineering and MechanicsLanzhou UniversityLanzhou 730000China

Contact force is related to the mechanical response of superconducting strands under a large electromagnetic body force,which is important for the safety of the international t hermonuclear experimen tai reac tor(ITER)magne t struc *** to the complex st rue ture of the cable-in-conduit conductor(CICC),the component unit of the ITER magnet,and the extreme operating environment,the research on the strand contact force caused by the electromagnetic force has been progressing *** this study,a two-dimensional(2D)theoretical model based on the granular elemen t method is construe ted to compute the contac t forces among some opaque and non-photoelastic ferromagnetic particles which are placed in a non-uniform magnetic *** the experiment,the contact deformations of these particles may be obtained by the digital image correlation *** also propose a method,which is similar to the least-squares method,to calculate the electromagnetic body forces of different ***,the distributional and statistical characteristics of the contac t force chains and contact angles are presen *** is considered that the method proposed in this paper is suitable for the contact force analysis of the cross section of superconducting strands in the ITER CICC that is subjected to a transverse elec-tromagnetic *** the end,this 2D theoretical model is generalized to the three-dimensional(3D)case,and the concise mathematical framework is presented.

关键词： Contact force Electromagnetic force Superconducting strand Cross section

A wavelet approach for active-passive vibration control of laminated plates

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Acta Mechanica Sinica 2012年第2期28卷 520-531页

作者： Ji-Zeng Wang Xiao-Min Wang you-he zhou Key Laboratory of Mechanics on Disaster and Environment in Western China the Ministry of Education of Chinaand Department of Mechanics and Engineering SciencesSchool of Civil Engineering and MechanicsLanzhou University730000 LanzhouChina

As an extension of the wavelet approach to vi- bration control of piezoelectric beam-type plates developed earlier by the authors, this paper proposes a hybrid active- passive control strategy for suppressing vibrations of lami- nated rectangular plates bonded with distributed piezoelec- tric sensors and actuators via thin viscoelastic bonding lay- ers. Owing to the low-pass filtering property of scaling func- tion transform in orthogonal wavelet theory, this wavelet- based control method has the ability to automatically filter out noise-like signal in the feedback control loop, hence re- ducing the risk of residual coupling effects which are usu- ally the source of spillover instability. Moreover, the exis- tence of thin viscoelastic bonding layers can further improve robustness and reliability of the system through dissipating the energy of any other possible noise induced partially by numerical errors during the control process. A simulation procedure based on an advanced wavelet-Galerkin technique is suggested to realize the hybrid active-passive control pro- cess. Numerical results demonstrate the efficiency of the pro- posed approach.

关键词： Wavelets Piezoelectric structures Hybridactive-passive control Rectangular plate Viscoelastic ma-terial ~ Numerical simulation

Bifurcation of a Swelling Gel with a Mechanical Load and Geometric Constraint

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Chinese Physics Letters 2011年第11期28卷 253-256页

作者： XUE Feng YONG Hua-Dong zhou you-he Key Laboratory of Mechanics on Disaster and Environment in Western China(Ministry of Education of China) and Department of MechanicsLanzhou UniversityLanzhou 730000

We present an analysis of the bifurcation phenomenon of a gel in contact with a *** a Mooney–Rivlin form-free energy function is introduced,an asymmetric swelling may appear for a gel swelling under uniaxial constraint or subjected to equal dead loads,which results in an interesting pitchfork bifurcation *** present an analytical investigation of this problem based on the classical theory of continuum *** bifurcation points are obtained for different values of the chemical potential of the solvent *** results demonstrate that the free swelling of the gel under uniaxial constraint will not result in the bifurcation unless further mechanical loads are applied.

关键词： bifurcation swelling constraint

Thermoelastic Stress in a Functionally Graded Infinite Plate with Electromagnetic Wave Absorption

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Chinese Physics Letters 2012年第11期29卷 165-168页

作者： TIAN Hong-Yan WANG Xing-Zhe zhou you-he Key Laboratory of Mechanics on Disaster and Environment in Western China(Ministry of Education) and College of Civil Engineering and MechanicsLanzhou UniversityLanzhou 730000

We present an analysis of thermal and thermoelastic behaviors of a functionally graded infinite plate taking into account electromagnetic wave *** treat with the inhomogeneity of functionally graded wave-absorbing(FGWA)materials,the plate is approximated by subdividing it into thin homogeneous layers to solve the governing equations together with proper boundary and connecting *** results illustrate that the FGWA plate is a broadband type absorber with electromagnetic wave *** choosing proper material gradation character and the thickness of the FGWA plate,it is possible to obtain a good performance of electromagnetic wave absorption and thermoelastic stress characteristics.

关键词： absorption plate graded

Accelerated Primal-Dual Projection Neurodynamic Approach With Time Scaling for Linear and Set Constrained Convex Optimization Problems

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IEEE/CAA Journal of Automatica Sinica 2024年第6期11卷 1485-1498页

作者： you Zhao Xing he Mingliang zhou Tingwen Huang Chongqing Key Laboratory of Nonlinear Circuits and Intelligent Information Processing College of Electronic and Information EngineeringSouthwest UniversityChongqing 400715China School of Computer Science Chongqing UniversityChongqing 400044China Department of Mathematics Texas A&M University at QatarDoha 23874Qatar IEEE

The Nesterov accelerated dynamical approach serves as an essential tool for addressing convex optimization problems with accelerated convergence *** previous studies in this field have primarily concentrated on unconstrained smooth con-vex optimization *** this paper,on the basis of primal-dual dynamical approach,Nesterov accelerated dynamical approach,projection operator and directional gradient,we present two accelerated primal-dual projection neurodynamic approaches with time scaling to address convex optimization problems with smooth and nonsmooth objective functions subject to linear and set constraints,which consist of a second-order ODE(ordinary differential equation)or differential conclusion system for the primal variables and a first-order ODE for the dual *** satisfying specific conditions for time scaling,we demonstrate that the proposed approaches have a faster conver-gence *** only requires assuming convexity of the objective *** validate the effectiveness of our proposed two accel-erated primal-dual projection neurodynamic approaches through numerical experiments.

关键词： Accelerated projection neurodynamic approach lin-ear and set constraints projection operators smooth and nonsmooth convex optimization time scaling.

Mechanics of Tokamak fusion components

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Theoretical & Applied Mechanics Letters 2019年第3期9卷 145-146页

作者： you-he zhou Mingjiu Ni the School of Engineering Science at University of Chinese Academy of Sciences

Fusion is an ideal clean energy for human being utilized in the future. Much more significant research progress for such new energy exploited in a limited finite space of the high temperature plasma flow constrained by strong magnetic fields of superconducting magnets has been achieved on Tokamak research, which comes to a new era with the international joint efforts from China, Europe, India, Japan, Korea, Russia and United States for building the international thermonuclear experimental reactor (ITER). The plasma chamber and magnets are key components of a fusion power reactor system.

关键词： Mechanics of Tokamak fusion components

Multi-core-shell-structured LiFePO_(4)@Na_(3)V_(2)(PO_(4))_(3)@C composite for enhanced low-temperature performance of lithium-ion batteries

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Rare Metals 2021年第4期40卷 828-836页

作者： Xing-Xing Gu Shuang Qiao Xiao-Lei Ren Xing-Yan Liu you-zhou he Xiao-Teng Liu Tie-Feng Liu Chongqing Key Laboratory of Catalysis and New Environmental Materials College of Environment and ResourcesChongqing Technology and Business UniversityChongqing 400067China Faculty of Engineering and Environment Northumbria UniversityNewcastle upon Tyne NE18STUK GRINM Group Co. Ltd.Beijing 100088China College of Materials Science and Engineering Zhejiang University of TechnologyHangzhou 310014China

In this work,a multi-core-shell-structured LiFePO_(4)@Na_(3) V_(2)(PO_(4))_(3)@C(LFP@NVP@C) composite was successfully designed and prepared to address inferior low-temperature performance of LiFePO_(4) cathode for lithium-ion *** electron microscopy(TEM) confirms the inner NVP and outer carbon layers coexisted on the surface of LFP *** evaluated at low-temperature operation,LFP@NVP@C composite exhibits an evidently enhanced electrochemical performance in term of higher capacity and lower polarization,compared with LFP@*** at-10℃ with 0.5 C,LFP@NVP@C delivers a discharge capacity of ca.96.9 mAh-g^(-1) and discharge voltage of ca.3.3 V,which is attributed to the beneficial contribution of NVP *** ICON-structured NVP with an open framework for readily insertion/desertion of Li+ will effectively reduce the polarization for the electrochemical reactions of the designed LFP@NVP@C composite.

关键词： LiFePO_(4)@Na_(3)V_(2)(PO_(4))_(3)@C composite Multi-core-shell Low-temperature Lithium-ion batteries