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Communications in Theoretical Physics 2005年第2期43卷 193-196页

作者： LUOShao-Kai JIAli-qun CAIJian-le InstituteofMathematicalMechanicsandMathematicalPhysics ZhejiangSci-TechUnivcrsityHangzhou310018China／／InstituteofMathematicalMechanicsandMathematicalPhysicsChangshaUniversityChangsha410003China ScienceCollegeofSouthern YangtzeUniversityWuxi214063China DepartmentofPhysics HangzhouTeachersCollegeHangzhou310018China

For the holonomic nonconservative system, by using the Noether symmetry, a non-Noether conserved quantity is obtained directly under general infinitesimal transformations of groups in which time is variable. At first,the Noether symmetry, lie symmetry, and Noether conserved quantity are given. Secondly, the condition under which the Noether symmetry is a lie symmetry under general infinitesimal transformations is obtained. Finally, a set of nonNoether conserved quantities of the system are given by the Noether symmetry, and an example is given to illustrate the application of the results.

关键词： holonomic conservative system noether symmetry non-Noether conservedquantity general inifinitesimal transformations of groups

Thermodynamic investigation of phase equilibria in Al–Si–V system

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Journal of Materials Science & Technology 2018年第9期34卷 1592-1601页

作者： qun Luo Kang li Qian li State Key Laboratory of Advanced Special Steel & Shanghai Key Laboratory of Advanced Ferrometallurgy & School of Materials Science and Engineering Shanghai UniversityShanghai 200072 China Materials Genome Institute Shanghai UniversityShanghai 200444 China Shanghai Institute of Materials Genome Shanghai 200444 China

The Al-Si-V system is assessed to understand the phase equilibria of V-containing（3 d transition metal）Al-Si alloys, which are generally of great importance for technical applications. Four annealed alloys were prepared to study the phase equilibria of Al-rich corner（V ≤ 23.3 at.%, Si ≤ 57.6 at.%） in the temperature range of 500-930 ℃. The microstructure and phase constituents of the samples were determined by X-ray diffraction（XRD） and scanning electron microscopy（SEM） equipped with energy dispersive X-ray spectrometer（EDS）, The existence of ternary phase τ（Al（0.6） Si（1.4） V, TiSi2-type） was confirmed with the composition ranging from 17.98 to 18.59 at.% Al and 48.89-49.20 at.% Si. However, it did not equilibrate with fcc（Al） below 868℃, which was determined by differential scanning calorimetry（DSC）. The Si3 V5 appeared in Al58 5 Si（18.3） V（23.2） and Al64 7 Si（20.2） V（15.1） alloys annealed at 500 ℃. It nearly disappeared after3000 h-annealing and its thermodynamic stability was discussed. According to the measured phase relationships, the thermodynamic description of Al-Si-V system was optimized combing with the enthalpies of formation of binary and ternary compounds obtained by density functional theory（DFT）. The Si-V system was modified to obtain the congruent liquidus of Si3 V5 and enthalpy of formation of Si3 V5 and Si2 V with experimental data. By comparing the calculated phase equilibria and phase transitions with experimental data, it showed that a good agreement was reached. The description of Al-Si-V system could be used to guide the development of Al-Si alloys.

关键词： Phase equilibrium Al-Si alloy CALPHAD method Intermetallic compounds Enthalpy of formation

Complex dynamics of a harmonically excited structure coupled with a nonlinear energy sink

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Acta Mechanica Sinica 2017年第4期33卷 801-822页

作者： Jian Zang li-qun Chen Shanghai Institute of Applied Mathematics and Mechanics Shanghai University Shanghai 200072 China Shanghai Key Laboratory of Mechanics in Energy Engineering Shanghai 200072 China Department of Mechanics Shanghai UniversityShanghai 200444 China

Nonlinear behaviors are investigated for a structure coupled with a nonlinear energy sink. The structure is linear and subject to a harmonic excitation, modeled as a forced single-degree-of-freedom oscillator. The nonlinear energy sink is modeled as an oscillator consisting of a mass,a nonlinear spring, and a linear damper. Based on the numerical solutions, global bifurcation diagrams are presented to reveal the coexistence of periodic and chaotic motions for varying nonlinear energy sink mass and stiffness. Chaos is numerically identified via phase trajectories, power spectra,and Poincaré maps. Amplitude-frequency response curves are predicted by the method of harmonic balance for periodic steady-state responses. Their stabilities are *** Hopf bifurcation and the saddle-node bifurcation are determined. The investigation demonstrates that a nonlinear energy sink may create dynamic complexity.

关键词： bifurcation excited saddle harmonic chaotic oscillator stiffness freedom branches modeled

Approximate and numerical analysis of nonlinear forced vibration of axially moving viscoelastic beams

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Acta Mechanica Sinica 2011年第3期27卷 426-437页

作者： Hu Ding li-qun Chen Shanghai Institute of Applied Mathematics and Mechanics Shanghai University 200072 Shanghai China Department of Mechanics Shanghai University 200436 Shanghai China

Steady-state periodical response is investigated for an axially moving viscoelastic beam with hybrid supports via approximate analysis with numerical confirmation. It is assumed that the excitation is spatially uniform and temporally harmonic. The transverse motion of axially moving beams is governed by a nonlinear partial-differential equation and a nonlinear integro-partial-differential equation. The material time derivative is used in the viscoelastic constitutive relation. The method of multiple scales is applied to the governing equations to investigate primary resonances under general boundary conditions. It is demonstrated that the mode uninvolved in the resonance has no effect on the steady-state response. Numerical examples are presented to demonstrate the effects of the boundary constraint stiffness on the amplitude and the stability of the steady-state response. The results derived for two governing equations are qualitatively the same,but quantitatively different. The differential quadrature schemes are developed to verify those results via the method of multiple scales.

关键词： Axially moving beam. Nonlinearity . Mate-rial time derivative . Method of multiple scales. Differentialquadrature method

An ontological metamodeling framework for semantic simulation model engineering

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Journal of Systems Engineering and Electronics 2020年第3期31卷 527-538页

作者： leI Yonglin ZHU Zhi li qun School of Systems Engineering National University of Defense TechnologyChangsha 410073China

Recently,the ontological metamodel plays an increasingly important role to specify systems in two forms:ontology and *** is a descriptive model representing reality by a set of concepts,their interrelations,and *** the other hand,metamodel is a more classical,but more powerful model in which concepts and relationships are represented in a prescriptive *** study firstly clarifies the difference between the two approaches,then explains their advantages and limitations,and attempts to explore a general ontological metamodeling framework by integrating each characteristic,in order to implement semantic simulation model *** a proof of concept,this paper takes the combat effectiveness simulation systems as a motivating case,uses the proposed framework to define a set of ontological composable modeling frameworks,and presents an underwater targets search scenario for running simulations and analyzing ***,this paper expects that this framework will be generally used in other fields.

关键词： ontology metamodeling semantic composability model-driven engineering(MDE)

Coupling electro-mechanical behaviors in the interdigital electrode device of ferroelectrics

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Acta Mechanica Sinica 2021年第4期37卷 649-661,I0003页

作者： Suxin Pan Shilin Xie qun li State Key Laboratory for Strength and Vibration of Mechanical Structures Xi’an Jiaotong UniversityXi’an 710049China

The electro-mechanical coupling behaviors of ferroelectric devices with interdigital electrodes may become complicated due to the material inhomogeneity and local field concentration under the complex working *** this paper,a ferroelectric model,drawn from the typical interdigital electrode structure of a ferroelectric sensor,is established based on phase field theory,to study the polarization evolution and explore the evolution laws in *** results show that there appears ferroelectric creep even under an applied electric field below the coercive field ***,the configurational force theory is introduced to investigate the mechanical behaviors related to polarization switching in the ferroelectric samples with interdigital *** is found that configurational force and polarization have similar evolution laws in both time evolving and space *** considering the configurational force as the driving force,it is possible to predict the potential direction of polarization evolution and explore its evolution mechanism in ferroelectrics,demonstrating the configurational force as a useful parameter for describing mechanical behavior during the polarization evolution and a powerful tool for investigating the evolution mechanism of microstructure with coupling effects in ferroelectric materials.

关键词： Phase field modeling Configurational force Polarization evolution Domain switching Interdigital electrode

Support Vector Machine active learning for 3D model retrieval

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2007年第12期8卷 1953-1961页

作者： leNG Biao QIN Zheng li li-qun Department of Computer Science and Technology Tsinghua University Beijing 100084 China School of Software Tsinghua University Beijing 100084 China

In this paper, we present a novel Support Vector Machine active learning algorithm for effective 3D model retrieval using the concept of relevance feedback. The proposed method learns from the most informative objects which are marked by the user, and then creates a boundary separating the relevant models from irrelevant ones. What it needs is only a small number of 3D models labelled by the user. It can grasp the user＇s semantic knowledge rapidly and accurately. Experimental results showed that the proposed algorithm significantly improves the retrieval effectiveness. Compared with four state-of-the-art query refinement schemes for 3D model retrieval, it provides superior retrieval performance after no more than two rounds of relevance feedback.

关键词： 3D model retrieval Shape descriptor Relevance feedback Support Vector Machine (SVM) Active learning

玉米和类玉米杂交后代异染色质纽的遗传稳定性分析

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武汉大学学报（理学版） 2003年第4期49卷 528-532页

作者：韩永华郭乐群李冬郁谷明光宋运淳武汉大学生命科学学院/植物发育生物学教育部重点实验室中国科学院遗传研究所北京100101 广西畜牧研究所广西南宁530001

利用玉米的近缘亲属摩擦禾的基因组DNA ,对玉米自交系 330、二倍体多年生类玉米及其远缘杂交孤雌生殖后代异源种质纯系 5 4 0的染色体进行比较基因组原位杂交 ,发现上述 3个供试种染色体上的异染色质纽因杂交信号极强而能被清楚地显示 ... 详细信息

利用玉米的近缘亲属摩擦禾的基因组DNA ,对玉米自交系 330、二倍体多年生类玉米及其远缘杂交孤雌生殖后代异源种质纯系 5 4 0的染色体进行比较基因组原位杂交 ,发现上述 3个供试种染色体上的异染色质纽因杂交信号极强而能被清楚地显示 .与亲代相比 ,5 4 0中出现异染色质纽数目减少的现象 .

关键词：玉米二倍体多年生类玉米摩擦禾比较基因组原位杂交异染色质纽遗传稳定性分子显带遗传育种

Progress of Studies on Multi-Color Long Afterglow Luminescence Materials

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Journal of Rare Earths 2004年第z1期22卷 295-301页

作者： li qun Teng Xiaoming General Research Institute for Nonferrous Metals Beijing 100088 Grirem Advanced Materials Co.Ltd.Beijing 100088 China Institute of Chemistry and Material Science Anhui Normal University Wuhu241000 China

Progress of studies on various multi-color long afterglow luminescence materials was *** luminescent mechanism of long afterglow behavior were *** research and development prospects about the materials were proposed.

关键词： long afterlow materials mechanism luminescence rare earths

Resource allocation in cognitive wireless powered communication networks with wirelessly powered secondary users and primary users

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Science China(Information Sciences) 2019年第2期62卷 224-229页

作者： Ding XU qun li Wireless Communication Key Lab of Jiangsu Province Nanjing University of Posts and Telecommunications Jiangsu Key Lab of Big Data Security and Intelligent Processing Nanjing University of Posts and Telecommunications

Dear editor,Wireless powered communication networks(WPCNs) are popular especially for wireless sensor networks where sensors can be wirelessly powered. For coordinating wireless power and information transfer, Ju and Zhang in their pioneer work [1] proposed a "harvest-then-transmit" protocol for WPCN, where the time for wireless power transfer (WPT) and wireless information transfer(WIT) is divided into two phases:the WPT phase and WIT phase. Meanwhile, cognitive radio (CR)

关键词： WIT Resource allocation in cognitive wireless powered communication networks with wirelessly powered secondary users and primary users