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Acta Mechanica Solida Sinica 2017年第3期30卷 271-284页

作者： Zhizhong Yan Yangyang Wang Chuanzeng Zhang School of Mathematics and Statistics Beijing Institute of Technology Department of Civil Engineering University of Siegen

The localization characteristics of the in-plane elastic waves in locally resonant aperiodic phononic crystals are examined in this study. In particular, the phononic crystals generated according to the Thue-Morse, Rudin-Shapiro and Period-Doubling sequences are theoretically investigated by using the extended transfer matrix method. For comparison, the binary and ternary locally resonant systems are considered, and their band structures are characterized by using the localization factors. Moreover, the influences of structural arrangement, material combination, incidence angle, number of components, length ratio, and random disorder on the band structures are also discussed. Some novel and interesting phenomena are observed and discussed.

关键词： Phononic crystals Aperiodicity Wave localization Localization factor Transfer matrix method

Algorithm for evaluating distance-based entanglement measures

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Chinese Physics B 2023年第8期32卷 195-200页

作者：胡奕轩刘烨超尚江伟 Key Laboratory of Advanced Optoelectronic Quantum Architecture and Measurement of Ministry of Education School of PhysicsBeijing Institute of TechnologyBeijing 100081China Naturwissenschaftlich-Technische Fakultät Universität SiegenSiegen 57068Germany

Quantifying entanglement in quantum systems is an important yet challenging task due to its NP-hard *** this work,we propose an efficient algorithm for evaluating distance-based entanglement *** approach builds on Gilbert's algorithm for convex optimization,providing a reliable upper bound on the entanglement of a given arbitrary *** demonstrate the effectiveness of our algorithm by applying it to various examples,such as calculating the squared Bures metric of entanglement as well as the relative entropy of entanglement for GHZ states,W states,Horodecki states,and chessboard *** results demonstrate that our algorithm is a versatile and accurate tool that can quickly provide reliable upper bounds for entanglement measures.

关键词： quantum information entanglement measurement convex optimization

Band structures of transverse waves in nanoscale multilayered phononic crystals with nonlocal interface imperfections by using the radial basis function method

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Acta Mechanica Sinica 2017年第2期33卷 415-428页

作者： Zhizhong Yan Chunqiu Wei Chuanzeng Zhang School of Mathematics and Statistics Beijing Institute of Technology Beijing 100081 China Beijing Key Laboratory on MCAACI Beijing Institute of Technology Beijing 100081 China Department of Civil Engineering University of Siegen Siegen 57068 Germany

A radial basis function collocation method based on the nonlocal elastic continuum theory is developed to compute the band structures of nanoscale multilayered phononic crystals. The effects of nonlocal imperfect interfaces on band structures of transverse waves propagating obliquely or vertically in the system are studied. The correctness of the present method is verified by comparing the numerical results with those obtained by applying the transfer matrix method in the case of nonlocal perfect interface. Furthermore, the influences of the nanoscale size, the impedance ratio and the incident angle on the cut-off frequency and band structures are investigated and discussed in detail. Numerical results show that the nonlocal interface imperfections have significant effects on the band structures in the macroscopic and microscopic scale.

关键词： Radial basis function Phononic crystal Nanoscale Band structure Nonlocal imperfect interface

SOLUTION OF THE PLANE STRESS PROBLEMS OF STRAIN-HARDENING MATERIALS DESCRIBED BY POWER-LAW USING THE COMPLEX PSEUDO-STRESS FUNCTION

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Applied Mathematics and Mechanics(English Edition) 1991年第5期12卷 481-492页

作者：王子昆魏雪霞高信林 Xian Jiaotong univ. Xian Lanzhou univ. Lanzhou Ganstt univ. of Tech. Lanzhou

In the present paper, the compatibility equation for the plane stress problems of power-law materials is transformed into a biharmonic equation by introducing the so-called complex pseudo-stress function, which makes it possible to solve the elastic-plastic plane stress problems of strain hardening materials described by power-law using the complex variable function method like that in the linear elasticity theory. By using this general method, the close-formed analytical solutions for the stress, strain and displacement components of the plane stress problems of power-law materials is deduced in the paper, which can also be used to solve the elasto-plastic plane stress problems of strain-hardening materials other than that described by power-law. As an example, the problem of a power-law material infinite plate containing a circular hole under uniaxial tension is solved by using this method, the results of which are compared with those of a known asymptotic analytical solution obtained by the perturbation method.

关键词： Elasticity Theory Elastoplasticity Strain Analysis

Aeroelastic analysis and flutter control of wings and panels:A review

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International Journal of Mechanical System Dynamics 2021年第1期1卷 5-34页

作者： Yuyang Chai Wei Gao Benjamin Ankay Fengming Li Chuanzeng Zhang Department of Engineering Mechanics College of Aerospace and Civil EngineeringHarbin Engineering UniversityHarbinChina Department of Civil Engineering University of SiegenSiegenGermany

Flutter is a self‐excited vibration under the interaction of the inertial force,aero-dynamic force,and elastic force of the *** the flutter occurs,the aircraft structures will exhibit limit cycle oscillation,which will cause catastrophic accidents or fatigue damage to the ***,it is of great theoretical and practical significance to study the aeroelastic characteristics and flutter control for improving the aeroelastic stability of aircraft *** paper reviews the recent advances in aeroelastic analysis and flutter control of wings and panel *** me-chanism of aeroelastic flutter of wings and panels is *** research methods of aeroelastic flutter for different structures developed in recent years are briefly *** control strategies including the linear and nonlinear control algorithms as well as the active flutter control results of wings and panels are ***,the paper ends with conclusions,which highlight challenges of the development in aeroelastic analysis and flutter control,and provide a brief outlook on the future *** study aims to present a comprehensive under-standing of aeroelastic analysis and flutter *** can also provide guidance on the design of new wings and panel structures for improving their aeroelastic stability.

关键词： aeroelastic analysis flutter control limit cycle oscillation panel structures wings

Cobalt-iron oxide/black phosphorus nanosheet heterostructure:Electrosynthesis and performance of(photo-)electrocatalytic oxygen evolution

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Nano Research 2023年第5期16卷 6057-6066页

作者： Man Zhao Xiaoru Cheng He Xiao Jianru Gao Shoufeng Xue Xiaoxia Wang Haishun Wu Jianfeng Jia Nianjun Yang Key Laboratory of Magnetic Molecules&Magnetic Information Materials Ministry of Education The School of Chemical and Material ScienceShanxi Normal UniversityTaiyuan 030000China Institute of Materials Engineering University of SiegenSiegen 57076Germany

Highly active,stable,and cut-price(photo-)electrocatalysts are desired to overwhelm high energy barriers for anodic oxygen evolution reaction ***,a heterostructure of cobalt-iron oxide/black phosphorus nanosheets is in-situ synthesized via a facile and novel three-electrode electrolysis *** black phosphorus is exfoliated into its nanosheets at the cathode while the CoFe oxide is derived directly from the metal wire anode during the electrolysis *** heterostructure exhibits excellent electrocatalytic oxygen evolution reaction(OER)performance,and the overpotential at 10 mA·cm^(−2)is 51 mV lower than that of the commercial RuO_(2)*** superior OER performance stems from the favorable adsorption behavior and an enlarged electrochemical active surface area of the *** reveal the origin of excellent OER performance from the point of adsorption strength of OH*,methanol oxidation reaction(MOR)test is applied under the identified OER operating *** introduction of light illumination enhances the OER activity of this *** overpotential drops down to 280 mV,benefiting from pronounced photochemical response of black phosphorus nanosheets and iron oxide inside the *** work develops a new electrochemical method to construct high performance and light-sensitive heterostructures from black phosphorus nanosheets for the OER.

关键词： electrosynthesis oxygen evolution reaction black phosphorus cobalt oxide iron oxide

Research on Characteristics of the Lateral Settlement Trough Caused by Shield Construction

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Journal of Shanghai Jiaotong univ.rsity(Science) 2006年第4期11卷 525-529,542页

作者：璩继立葛修润 univ. of Shanghai for Science and Technology Shanghai Jiaotong univ.

The characteristics of settlement trough induced by shield construction in soft soil area in Shanghai were analyzed based on test materials in situ. The shape of the trough, the relationship between trough and buried depth of tunnel, trough evolvement with time and relationship between trough width coefficient and buried depth of tunnel and time were profoundly researched by mainly using the methods of statistics, fitting, comparison and drawing, deriving the conclusions which are of important guidance in the area.

关键词： settlement trough shield construction buried depth of tunnel width coefficient

Effect of Heat Treatment on the Microstructure and Residual Stresses in (Ti,Al)N Films

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Journal of Materials Science & Technology 2011年第5期27卷 385-392页

作者： Ving Yang Shengsheng Zhao Jun Gong Xin Jiang Chao Sun State Key Laboratory of Corrosion and Protection Institute of Metal Research Chinese Academy of SciencesShenyang 110016 China Instituteof Materials Engineering University of Siegen Paul-Bonatz-Str. 9-11 Siegen 57076 Germany

（Ti,AI）N films were fabricated by arc ion plating （ALP） and then annealed within a range of temperatures from 200 to 500℃ for 30 rain in vacuum. The results indicate that the average residual stresses decrease slightly from -5.84 to -4.98 GPa with increasing annealing temperature. The stress depth distribution evolves from a sharp ＂bell＂ shape to a mild ＂bell＂ shape, suggesting a more uniform stress state in the annealed films. The microstructure of the films was also investigated in detail. The as-deposited film consists of fine columnar crystals with an amorphous phase at the interface. During heat treatment, the columnar subgrain growth was observed; meanwhile, the phenomenon of crystallization has been identified at the interface. Further more, the relationship between the residual stresses and the microstructure of the films was explored and highlighted. In addition, there is no hardness degradation of the films during heat treatment.

关键词： Arc ion plating Heat treatment Microstructure Stress distribution (Ti,AI)N

Crack propagation simulation in brittle elastic materials by a phase field method

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Theoretical & Applied Mechanics Letters 2019年第6期9卷 339-352页

作者： Xingxue Lu Cheng Li Ying Tie Yuliang Hou Chuanzeng Zhang School of Mechanical Engineering Zhengzhou UniversityZhengzhou 450001China Department of Civil Engineering University of SiegenD-57076 SiegenGermany

To overcome the difficulties of re-meshing and tracking the crack-tip in other computational methods for crack propagation simulations,the phase field method based on the minimum energy principle is introduced by defining a continuous phase field variable(x)∈[0,1]to characterize discontinuous cracks in brittle *** method can well describe the crack initiation and propagation without assuming the shape,size and orientation of the initial crack in *** this paper,a phase field method based on Miehe's approach[Miehe et al.,***.(2010)]is applied to simulate different crack propagation problems in twodimensional(2D),isotropic and linear elastic *** numerical implementation of the phase field method is realized within the framework of the finite element method(FEM).The validity,accuracy and efficiency of the present method are verified by comparing the numerical results with other reference results in *** numerical examples are presented to show the effects of the loading type(tension and shear),boundary conditions,and initial crack location and orientation on the crack propagation path and force-displacement ***,for a single edge-cracked bi-material specimen,the influences of the loading type and the crack location on the crack propagation trajectory and force-displacement curve are also investigated and *** is demonstrated that the phase field method is an efficient tool for the numerical simulation of the crack propagation problems in brittle elastic materials,and the corresponding results may have an important relevance for predicting and preventing possible crack propagations in engineering applications.

关键词： Brittle fracture Phase field method Crack propagation Finite element method

Sex differences in color discrimination and serial reversal learning in mollies and guppies

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Current Zoology 2019年第3期65卷 323-332页

作者： Theodora FUSS Klaudia WITTE Research Group of Ecology and Behavioral Biology Institute of Biology Department of Chemistry and Biology University of Siegen Adolf-Reichwein-Str. 2 57076 Siegen Germany

Behavioral flexibility provides an individual with the ability to adapt its behavior in response to environmental changes. Studies on mammals, birds, and teleosts indicate greater behavioral flexibility in females. Conversely, males appear to exhibit greater behavioral persistenee. We, therefore, investigated sex differences in behavioral flexibility in 2 closely related molly species (Poecilia latipinna, P. mexicana) and their more distant relative, the guppy P. reticulata by comparing male and female individuals in a serial, visual reversal learning task. Fish were first trained in color discrimination, which was quickly learned by all females (guppies and mollies) and all molly males alike. Despite continued training over more than 72 sessions, male guppies did not learn the general test procedure and were, therefore, excluded from further testing. Once the reward contingency was reversed serially, molly males of both species performed considerably better by inhibiting their previous response and reached the learning criterion sign讦icantly faster than their respective con specific females. Moreover, Atlantic molly males clearly outperformed all other individuals (males and females) and some of them even reached the level of 1-trial learning. Thus, the apparently un iversal pattern of higher female behavioral flexibility seems to be in verted in the 2 examined molly species, although the evolutionary account of this pattern remains highly speculative. These findings were complemented by the observed lower neophobia of female sailfin mollies compared with their male con specifics. This sex differe nee was not observed in Atlantic mollies that were observed to be sigrdficantly less distressed in a novel situation than their consexuals. Hypothetically, sex differences in behavioral flexibility can possibly be explained in terms of the different roles that males and females play in mating competition, mate choice, and reproduction or, more gen erally, in complex socia

关键词： behavioural and cognitive flexibility colour discrimination neophobia serial reversal learning/Poecilia mexicana and Poecilia latipinna Poecilia reticulata