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Review of progress and challenges of key mechanical issues in high-field superconducting magnets

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National Science Review 2023年第3期10卷 29-50页

作者： you-he zhou Dongkeun Park Yukikazu Iwasa 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 Plasma Science and Fusion Center Francis Bitter Magnet LaboratoryMassachusetts Institute of Technology

The development of modern science and technology requires high magnetic fields exceeding 25 ***-generation high-temperature superconducting wires,***(REBa2Cu3O7-x,RE refers to Y,Gd,Dy,Eu and other rare-earth elements) coated conductors(CCs),have become the first choice for high-field magnet construction because of their high irreversible magnetic *** mechanical stresses caused by manufacturing,thermal mismatch and Lorenz forces closely influence electromagnetic performance during operation for REBCO *** addition,the recently studied screen currents have effects on the mechanical characteristics of high-field REBCO *** this review,the experimental and main theoretical works on critical current degradation,delamination and fatigue,and shear investigations on REBCO CCs,are reviewed at ***,research progress on the screening-current effect in the development of high-field superconducting magnets is ***,the key mechanical problems facing the future development of high-field magnets based on REBCO CCs are prospected.

关键词： REBCO second-generation high-temperature superconducting coated conductors (REBCO 2G-HTS CCs) high-field magnets mechanics screening-current effect

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

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.

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

Controllable rectification on the thermal conductivity of porous YBa_(2)Cu_(3)O_(7−x) superconductors from 3D-printing

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International Journal of Extreme Manufacturing 2023年第1期5卷 182-191页

作者： Yanbin Ma 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 UniversityLanzhouGansu 730000People’s Republic of China Department of Mechanics and Engineering Sciences College of Civil Engineering and MechanicsLanzhou UniversityLanzhouGansu 730000People’s Republic of China

Superconducting YBa_(2)Cu_(3)O_(7−x)(YBCO)bulks have promising applications in quasi-permanent magnets,levitation,***,a new way of fabricating porous YBCO bulks,named direct-ink-writing(DIW)3D-printing method,has been *** this method,the customized precursor paste and programmable shape are two main ***,we have put forward a new way to customize the YBCO 3D-printing precursor paste which is doped with Al_(2)O_(3)nanoparticles to obtain YBCO with higher thermal *** great rheological properties of precursor paste after being doped with Al_(2)O_(3)nanoparticles can help the macroscopic YBCO samples with high thermal conductivity fabricated stably with high crystalline and lightweight *** results show that the peak thermal conductivity of Al_(2)O_(3)-doped YBCO can reach twice as much as pure YBCO,which makes a great effort to reduce the quench propagation *** on the microstructure analysis,one can find that the thermal conductivity of Al_(2)O_(3)-doped YBCO has been determined by its components and *** addition,a macroscopic theoretical model has been proposed to assess the thermal conductivity of different microstructures,whose calculated results take good agreement with the experimental ***,a microstructure with high thermal conductivity has been ***,a macroscopic YBCO bulk with the presented high thermal conductivity microstructure has been fabricated by the Al_(2)O_(3)-doped *** with YBCO fabricated by the traditional 3D-printed,the Al_(2)O_(3)-doped structural YBCO bulks present excellent heat transfer *** customized design of 3D-printing precursor pastes and novel concept of structural design for enhancing the thermal conductivity of YBCO superconducting material can be widely used in other DIW 3D-printing materials.

关键词： Al_(2)O_(3)-doped YBCO thermal conductivity theoretical model controllable design DIW 3D-printing

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

Copper-catalyzed enantioselective desymmetrizing C（sp2）–H functionalization of azide-ynamides via α-imino copper carbenes

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Science China Chemistry 2024年第9期67卷 2982-2988页

作者： En-he Huang Li-Gao Liu you-Wei Yin Hao-Xuan Dong Ji-Jia zhou Xin Lu Bo zhou Long-Wu Ye Key Laboratory for Chemical Biology of Fujian Province and State Key Laboratory of Physical Chemistry of Solid Surfaces College of Chemistry and Chemical Engineering Xiamen University State Key Laboratory of Organometallic Chemistry Shanghai Institute of Organic Chemistry Chinese Academy of Sciences

α-Imino metal carbenes are versatile intermediates in organic synthesis, and have broad applications in the assembly of divergent N-heterocycles. However, the catalytic enantioselective desymmetrization based on α-imino metal carbenes has not been developed to date. herein, we disclose an enantioselective desymmetrizing C（sp2）–H functionalization of azide-ynamides via α-imino copper carbenes, leading to the efficient assembly of divergent chiral indoloazepines in generally moderate to excellent yields with high enantioselectivities. Notably, this reaction represents the first enantioselective desymmetrization based on α-imino metal carbenes. Further synthetic transformations and biological tests show the potential utility of this method. Moreover,computational studies are employed to elucidate the reaction mechanism and the origin of enantioselectivity.

关键词： enantioselective desymmetrization metal carbenes copper catalysis nitrene transfer alkynes

Maximum Correntropy Criterion-Based UKF for Loosely Coupling INS and UWB in Indoor Localization

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Computer Modeling in Engineering & Sciences 2024年第6期139卷 2673-2703页

作者： Yan Wang you Lu Yuqing zhou Zhijian Zhao Department of Computer and Communication Engineering Northeastern UniversityQinhuangdao066004China

Indoor positioning is a key technology in today’s intelligent environments,and it plays a crucial role in many application *** paper proposed an unscented Kalman filter(UKF)based on the maximum correntropy criterion(MCC)instead of the minimummean square error criterion(MMSE).This innovative approach is applied to the loose coupling of the Inertial Navigation System(INS)and Ultra-Wideband(UWB).By introducing the maximum correntropy criterion,the MCCUKF algorithm dynamically adjusts the covariance matrices of the system noise and the measurement noise,thus enhancing its adaptability to diverse environmental localization *** in the presence of non-Gaussian noise,especially heavy-tailed noise,the MCCUKF exhibits superior accuracy and robustness compared to the traditional *** method initially generates an estimate of the predicted state and covariance matrix through the unscented transform(UT)and then recharacterizes the measurement information using a nonlinear regression method at the cost of ***,the state and covariance matrices of the filter are updated by employing the unscented transformation on the measurement ***,to mitigate the influence of non-line-of-sight(NLOS)errors positioning accuracy,this paper proposes a k-medoid clustering algorithm based on bisection k-means(Bikmeans).This algorithm preprocesses the UWB distance measurements to yield a more precise position *** results demonstrate that MCCUKF is robust to the uncertainty of UWB and realizes stable integration of INS and UWB systems.

关键词： Maximum correntropy criterion unscented Kalman filter inertial navigation system ultra-wideband bisecting kmeans clustering algorithm

An efficient physics-guided Bayesian framework for predicting ground settlement profile during excavations in clay

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第4期16卷 1411-1424页

作者： Cong Tang Shuyu he Wanhuan zhou State Key Laboratory of Internet of Things for Smart City and Department of Civil and Environmental Engineering University of MacaoChina

Recently,the application of Bayesian updating to predict excavation-induced deformation has proven successful and improved prediction accuracy ***,updating the ground settlement profile,which is crucial for determining potential damage to nearby infrastructures,has received limited *** address this,this paper proposes a physics-guided simplified model combined with a Bayesian updating framework to accurately predict the ground settlement *** advantage of this model is that it eliminates the need for complex finite element modeling and makes the updating framework ***,the model is physically interpretable,which can provide valuable references for construction *** effectiveness of the proposed method is demonstrated through two field case studies,showing that it can yield satisfactory predictions for the settlement profile.

关键词： Bayesian updating Excavations Ground settlement profile Simplified model Uncertainty