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Coupled 3D discrete-continuum numerical modeling of pile penetration in sand

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2012年第1期13卷 44-55页

作者： jian ZHOU Qi-wei jian Jiao ZHANG jian-jun GUO Department of Geotechnical Engineering Tongji University Shanghai 200092 China School of Civil Engineering and Transportation Shanghai Technical College of Urban Management Shanghai 200432 China Sichuan Provincial Chuanjian Investigation and Design Institute Chengdu 610017 China

A coupled discrete-continuum simulation incorporating a 3D aspect and non-circular particles was performed to analyze soil-pile interactions during pile penetration in sand.A self-developed non-circular particle numerical simulation program was used which considered sand near the pile as interacted particles using a discrete element method;the sand away from the pile was simulated as a continuous medium exhibiting linear elastic *** domain analyzed was divided into two *** forces at the interface between the two zones were obtained from a discrete zone and applied to the continuum boundaries as nodal forces,while the interface velocities were obtained from the continuum zone and applied to the discrete *** show that the coupled discrete-continuum simulation can give a microscopic description of the pile penetration process without losing the discrete nature of the zone concerned,and may significantly improve computational efficiency.

关键词： Coupled numerical modeling Discrete-continuum Micro and macro 3D simulation Non-circular particles Pilepenetration mechanism

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定窑遗址出土制瓷原料的科学分析

光谱学与光谱分析 2025年第1期45卷 72-81页

作者：陈殿崔剑锋秦大树黄信李鑫北京师范大学历史学院陶瓷考古与艺术研究中心北京100875 考古科学教育部重点实验室(北京大学) 北京100871 浙大城市学院考古学系浙江杭州310015 河北省文物考古研究院河北石家庄050031 中国社会科学院考古研究所北京100101

首次通过窑址发掘出土的制瓷原料,复原了定窑不同时代的胎釉配方。对2009年定窑作坊遗址考古发掘所出五代至宋金时期二十余种制瓷原料开展了ED-XRF成分分析和XRD结构分析等光谱学分析。ED-XRF成分分析显示,这些原料可能包括单一原料和... 详细信息

首次通过窑址发掘出土的制瓷原料,复原了定窑不同时代的胎釉配方。对2009年定窑作坊遗址考古发掘所出五代至宋金时期二十余种制瓷原料开展了ED-XRF成分分析和XRD结构分析等光谱学分析。ED-XRF成分分析显示,这些原料可能包括单一原料和混合原料两种。其中单一原料包括岩石、粘土以及草木灰。混合原料则包括胎料和釉料两种。XRD结构分析表明用于定窑白瓷生产高岭土类原料是含有蒙脱石和方解石的伴生石英的长石类矿物原料。高铁粘土类原料由于铁含量特别高,应当是用于配黑釉的粘土。钙质原料的分析与康葆强等学者对定窑配釉用的灰料可能使用了40%的白灰和60%的松木灰配制的结论相同。同时,还发现了釉灰,即草木煅烧石灰石后形成的混合灰料。在分析定窑白瓷釉时,认为五代的白瓷釉可能使用了釉灰配制,因此定窑釉灰的使用可能推早到五代,这是目前发现使用釉灰配釉最早的实例。对制胎原料XRD晶相分析的结果表明,除了石英和高岭石占主要比重外,还含有长石、蒙脱石、方解石等岩石类矿物。从对单一原料的X射线衍射的分析结果看,石英是粘土以及岩石这类单一原料中都含有的一类矿物,因此可能石英并非必须要添加的胎体原料。石英和高岭石是粘土原料中的主要成分,因此制胎原料应该主要以岩石类原料和粘土作为主要配料。定窑细白瓷胎料可能使用了粘土类原料配合第一类岩石类原料的配方,其配比在金代时大约为1∶1左右,北宋时期可能约为7∶3(粘土∶岩石),五代时大概为6∶4左右。对制釉原料分析结果表明,定窑配釉原料是岩石类原料与釉灰配合形成的,五代、北宋时岩石和灰的比例约为9∶1,金代时石:灰达到了9.5∶0.5。这使得我们对定窑鼎盛时期的白瓷胎釉配方有了更加清晰的了解,从而为开展定窑的复烧提供了确凿的依据。

关键词：定窑制瓷原料光谱学分析

Variable Universe Fuzzy Control for Battery Equalization

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Journal of Systems Science & Complexity 2018年第1期31卷 325-342页

作者： ZHENG jian CHEN jian OUYANG Quan The State Key Laboratory of Industrial Control Technology College of Control Science and Engineering Zhejiang University

In order to avoid the overcharge and overdischarge damages, and to improve the lifetime of the lithium-ion batteries, it is essential to keep the cell voltages in a battery pack at the same level,i.e., battery equalization. Based on the bi-directional modified Cuk converter, variable universe fuzzy controllers are proposed to adaptively maintain equalizing currents between cells of a serially connected battery pack in varying conditions. The inputs to the fuzzy controller are the voltage differences and the average voltages of adjacent cell pairs. A large voltage difference requires large equalizing current while adjacent cells both with low/high voltages can only stand small discharge/charge currents. Compared with the conventional fuzzy control method, the proposed method differs in that the universe can shrink or expand as the effects of the input changes. This is important as the input may change in a small range. Simulation results demonstrate that the proposed variable universe fuzzy control method has fast equalization speed and good adaptiveness for varying conditions.

关键词： Cell equalization lithium-ion battery variable universe fuzzy control

MULTISYMPLECTIC FOURIER PSEUDOSPECTRAL METHOD FOR THE NONLINEAR SCHR■DINGER EQUATIONS WITH WAVE OPERATOR

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Journal of Computational Mathematics 2007年第1期25卷 31-48页

作者： jian Wang Department of Mathematics Shanghai Jiaotong University Division of Computational Science E-Institute of Shanghai Universities Shanghai 200240 China

In this paper, the multisymplectic Fourier pseudospectral scheme for initial-boundary value problems of nonlinear SchrSdinger equations with wave operator is considered. We investigate the local and global conservation properties of the multisymplectic discretization based on Fourier pseudospectral approximations. The local and global spatial conservation of energy is proved. The error estimates of local energy conservation law are also derived. Numerical experiments are presented to verify the theoretical predications.

关键词： Multisymplecticity Fourier pseudospectral method Local conservation laws

Superconductivity in topological semimetals

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National Science Review 2019年第2期6卷 199-202页

作者： jian Wang International Center for Quantum Materials School of Physics Peking University Collaborative Innovation Center of Quantum Matter CAS Center for Excellence in Topological Quantum Computation University of Chinese Academy of Sciences Beijing Academy of Quantum Information Sciences

Topological superconductors, where the bulk state shows superconducting gap and Majorana fermions constitute gapless edge states, have become one of the most important topics in physical sciences. Majorana fermions are their own antiparticles and Majorana quasiparticles in a solid-state system obey non-Abelian statistics, and thus can be used for faulttolerant topological quantum computation.

关键词： As Superconductivity in topological semimetals

CALCULATING　MODELS　OF　MASS　ACTION　CONCENTRATIONS　OF　BINARY　METALLIC　MELTS　INVOLVING　SOLID　SOLUTIONS

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中国有色金属学会会刊：英文版 1995年第2期5卷 16-22页

作者： Zhang, jian Univ of Science and Technology Beijing Beijing China

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关键词： activity short-range order coexistence theory mass action concentration

Recent Advances in Iterative Learning Control

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自动化学报 2005年第1期31卷 132-142页

作者： jian-XinXU DepartmentofElectricalandComputerEngineering NationalUniversityofSingapore4EngineeringDrive3117576Singapore

In this paper we review the recent advances in three sub-areas of iterative learning control (ILC): 1) linear ILC for linear processes, 2) linear ILC for nonlinear processes which are global Lipschitz continuous (GLC), and 3) nonlinear ILC for general nonlinear processes. For linear processes, we focus on several basic configurations of linear ILC. For nonlinear processes with linear ILC, we concentrate on the design and transient analysis which were overlooked and missing for a long period. For general classes of nonlinear processes, we demonstrate nonlinear ILC methods based on Lyapunov theory, which is evolving into a new control paradigm.

关键词：反复学习系统线性过程非线性过程自动控制系统

Twisted optical communications using orbital angular momentum

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Science China(Physics,Mechanics & Astronomy) 2019年第3期62卷 1-21页

作者： jian Wang Wuhan National Laboratory for Optoelectronics School of Optical and Electronic Information Huazhong University of Science and Technology

Angular momentum, a fundamental physical quantity, can be divided into spin angular momentum(SAM) and orbital angular momentum(OAM) in electromagnetic waves. Helically-phased or twisted light beams carrying OAM that exploit the spatial structure physical dimension of electromagnetic waves have benefited wide applications ranging from optical manipulation to quantum information processing. Using the two distinct properties of OAM, i.e., inherent orthogonality and unbounded states in principle, one can develop OAM modulation and OAM multiplexing techniques for twisted optical communications. OAM multiplexing is an alternative space-division multiplexing approach employing an orthogonal mode basis related to the spatial phase structure. In this paper, we review the recent progress in twisted optical communications using OAM in free space and fiber. The basic concept of momentum, angular momentum, SAM, OAM and OAM-carrying twisted optical communications,key techniques and devices of OAM generation/(de)multiplexing/detection, high-capacity spectrally-efficient free-space OAM links, fiber-based OAM links, and OAM processing functions are presented. Ultra-high spectral efficiency and petabit-scale freespace data links are achieved benefiting from OAM multiplexing. The key techniques and challenges of twisted optical communications are also discussed. Twisted optical communications using OAM are compatible with other existing physical dimensions such as frequency/wavelength, amplitude, phase, polarization and time, opening a possible way to facilitate continuous increase of the aggregate transmission capacity and spectral efficiency through N-dimensional multiplexing.

关键词： fiber optical communications free-space optical communications modulation multiplexing orbital angular momentum space-division multiplexing spectral efficiency twisted optical communications twisted light structured light

Mechanics criterion and factors affecting overburden stability in solid dense filling mining

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International Journal of Mining Science and Technology 2017年第3期27卷 407-413页

作者： Sun jian School of Energy and Safety Anhui University of Science & Technology State Key Laboratory for Geomechanics & Deep Underground Engineering China University of Mining & Technology

The effect of controlling strata movement in solid filling mining depends on the filling rate of the goal. However, the mechanical property of the overburden in the backfill stope and the designed size of the backfill mining workface should also be considered. In this study, we established a main roof strata model with loads in accordance with the theory of key strata to investigate the stability of the overburden in solid dense filling mining. We analyzed the stress distribution law of the main roof strata based on elastic thin plate theory. The results show that the position of the long side midpoint of the main roof strata failed more easily because of tensile yield, indicating that this position is the area where failure is likely to occur more easily. We also deduced the stability mechanics criterion of the main roof strata based on tensile yield criterion. The factors affecting the stability of the overburden in solid dense filling mining were also analyzed, including the thickness and elasticity modulus of the main roof strata, overlying strata loads, advanced distance and length of workface, and elastic foundation coefficient of backfill body. The research achievements can provide an important theoretical basis for determining the designed size of the solid dense filling mining workface.

关键词： Filling mining Strata movement Stability control Influencing factors Size design