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Earthquake Engineering and Engineering Vibration 2024年第1期23卷 35-50页

作者： Tang Yuchuan Wang Jiankang Wu Gang School of Civil Engineering Southeast UniversityKey Laboratory of Concrete and Prestressed Concrete Structures of the Ministry of EducationNanjing 211102China National and Local Joint Engineering Research Center for Intelligent Construction and Maintenance Nanjing 211102China

In seismology and earthquake engineering,it is fundamental to identify and characterize the pulse-like features in pulse-type ground *** capture the pulses that dominate structural responses,this study establishes congruence and shift relationships between response spectrum surfaces.A similarity search between spectrum surfaces,supplemented with a similarity search in time series,has been applied to characterize the pulse-like features in pulse-type ground *** identified pulses are tested in predicting the rocking consequences of slender rectangular blocks under the original ground ***,the prediction is promising for the majority of the ground motions where the dominant pulse is correctly identified.

关键词： velocity pulse ground motion surface similarity rocking overturning

Physical analysis and numerical simulation for the dynamic behaviour of vehicles in pitching oscillations or rocking motions

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Science China(Technological Sciences) 2007年第4期50卷 385-401页

作者： ZHANG HanXin1,2,3, ZHANG Zhao1,3, YUAN XianXu1,2, LIU Wei1, XIE YuFei1,2 & YE YouDa1,2 1 China Aerodynamics Research and Development Center, Mianyang 621000, China 2 National Laboratory for Computational Fluid Dynamics, Beijing University of Aeronautics and Astronautics, Beijing 100083, China 3 School of Aerospace, Tsinghua University, Beijing 100084, China 1. China Aerodynamics Research and Development Center Mianyan 621000 China 2. National Laboratory for Computational Fluid Dynamics Beijing University of Aeronautics and Astronautics Beijing 100083 China 3. School of Aerospace Tsinghua University Beijing 100084 China

Analytical methods of nonlinear dynamics and numerical simulations for the cou-pling equations of Navier-Stokes and flight mechanics are used to study the dynamic behaviour of pitching motions of reentry capsules with the variation of Mach number, and rocking motions of swept wings with the variation of angle of attack. Conditions under which the dynamic instability, Hopf bifurcation and saddle-node bifurcation occur are obtained. The node-saddle-node topological structure in the phase portrait, i.e. the state of bi-attractors (attracting basins) is described. The evolving process of dynamic behaviour and flow fields are given. The theories are compared with some numerical simulations conducted by the authors. Besides, some verifiable experi-mental results are cited. The agreement between them is very well.

关键词： physical analysis numerical simulation pitching oscillation rocking motion bifurcation

rocking Compliance of Rigid Rectangular Foundations on an Elastic Half-space

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Journal of Harbin Institute of Technology(New Series) 1995年第2期2卷 64-68页

作者：吴知丰

A closed-form solution is presented for rocking compliance of rigid rectangular foundations on an elastic half-space under a harmonic *** motion in the vicinity of the foundation is also *** examples are shown and comparisons between the results of the proposed approach and other methods are *** efficient computing method of rocking compliance can facilitate seismic response analysis of long dams and other large flexible bodies.

关键词： ss:Rigid foundation rocking compliance soil-foundation

rocking Block线碰撞离散化研究

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动力学与控制学报 2017年第4期15卷 330-334页

作者：张宏剑庄方方王辰季宝锋石玉红北京宇航系统工程研究所北京100076 中国运载火箭技术研究院研究发展中心北京100076

针对rocking Block中的线碰撞问题,首先采用离散化思想将线碰撞问题离散为多点碰撞系统,而后基于LZB方法对所建多点碰撞系统进行动力学建模.仿真结果表明随着离散点数的增加,基于LZB方法的多点碰撞模型能够很好地刻画rocking Block中的... 详细信息

针对rocking Block中的线碰撞问题,首先采用离散化思想将线碰撞问题离散为多点碰撞系统,而后基于LZB方法对所建多点碰撞系统进行动力学建模.仿真结果表明随着离散点数的增加,基于LZB方法的多点碰撞模型能够很好地刻画rocking Block中的相关线碰撞问题,且精度与离散程度紧密相关.

关键词：线碰撞多点碰撞非光滑动力学 rocking Block

Implementation of configuration dependent stiffness proportional damping for the dynamics of rigid multi-block systems

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Earthquake Engineering and Engineering Vibration 2003年第1期2卷 87-98页

作者： Yun Byeong Chae Jae Kwan Kim R & D Division Chungsuk Engineering57Garak-dongSongpa-kuSeoul138-802Korea Assistant Engineer School of Civil Urban and Geosystem EngineeringSeoul National UniversitySeoul151-742Korea Associate Professor

The distinct element method(DEM)has been used successfully for the dynamic analysis of rigid block sys- *** of many difficulties associated with DEM is modeling of *** this paper,new procedures are proposed for the damping modeling and its numerical implementation in distinct element analysis of rigid muhi-block *** stiff- ness proportional damping is constructed for the prescribed damping ratio,based on the non-zero fundamental frequency ef- fective during the time interval while the boundary conditions remain essentially *** this time interval,the funda- mental frequency can be estimated without complete eigenvalue *** damping coefficients will vary while the damp- ing ratio remains the same throughout the entire analysis.A new numerical procedure is developed to prevent unnecessary energy loss that can occur during the separation *** procedures were implemented in the development of the dis- tinet element method for the dynamic analyses of piled multi-block *** analysis results |or the single-block and two-block systems were in a good agreement with the analytic *** to the seismic analyses of piled four- block systems revealed that the new procedures can make a significant difference and may lead to much-improved results.

关键词： multi-block systems stiffness proportional damping rocking impact distinet element method rigid body dynamics

Simulation study on characteristics of information extraction in multiple-image radiography

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Nuclear Science and Techniques 2018年第5期29卷 87-97页

作者： Cui Zhang Xiao-Dong Pan Jing-Jie Ding Hong-Jie Shang Zhang-Gu Chen Yong-Fan Pu Gong-Ping Li School of Nuclear Science and Technology Lanzhou University Key Laboratory of Special Function Materials and Structure Design Ministry of Education Lanzhou University

Simulation experiments were performed to investigate the characteristics of information extraction in multiple-image radiography(MIR) based on geometrical optics approximation. Different Poisson noise levels were added to the simulation, and the results show that Poisson noise deteriorates the extraction results, with the degree of refraction > USAXS > absorption. The effects of Poisson noise are negligible when the detector's photon counts are about 1000 ph/pixel. A wider sampling range allows more accurate extraction results, but a narrower sampling range has a better signal-to-noise ratio for high Poisson noise levels, e.g., PN(10). The sampling interval can be suitably increased with a minor impact on the extraction results for low Poisson noise levels(PN(10000)). The extraction results are incomplete because a portion of the samplerocking curve is beyond the sampling range. This induces artifacts in the images, especially for strong refraction and USAXS signals. The artifacts are not obvious when the refraction angle and standard deviation of the USAXS are smaller than the sampling range by an order of *** general, the absorption barely affects the extraction results. However, additional Poisson noise will be generated when the sample is made of high-Z elements or has a large size due to the strong absorption. Here, the extraction results will deteriorate, and additional exposure time is required. This simulation provides important details on practical applications of MIR, with improvements in information extraction.

关键词： X-ray imaging Phase contrast rocking curve Multiple-image radiography

Comparison between the seismic response of 2D and 3D models of rigid blocks

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Earthquake Engineering and Engineering Vibration 2014年第1期13卷 151-162页

作者： Angelo Di Egidio Daniele Zulli Alessandro Contento Department of Civil Engineering Architecture and Environment(DICEAA)University of L'Aquila

A three-dimensional rigid body on the shape of a parallelepiped is modelled in order to rock on a side or a vertex of the base,in order to evaluate the seismic response of rigid blocks lying on a horizontal *** center of mass of the body is considered as eccentric with respect to its geometric *** seismic input,three Italian recorded accelerograms,with different spectral content,are *** study is mainly conducted to highlight the differences between the seismic response of 2D and 3D models of rigid blocks,with the aim to understand if,in some cases,the use of the 3D model of rigid block is required to obtain safer *** fact,the outcomes show that in some ranges of the geometrical and mechanical parameters that characterize the excitation and the body,a two-dimensional model,which is not able to consider the 3D rocking on a vertex,can provide unsafe *** particular,it is found that the overturning process of the three-dimensional block can occur under excitations which are lower than those which overturn a corresponding two-dimensional block.

关键词： seismic excitation 3D rigid block rectangular base rocking overturning

Sputtering of ZnO buffer layer on Si for GaN blue light emitting materials

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Science China(Technological Sciences) 2000年第1期43卷 55-59页

作者：贺洪波范正修姚振钰汤兆胜 Shanghai Institute of Optics and Fine Mechanics Chinese Academy of Sciences Shanghai 201800 China Institute of Semiconductors Chinese Academy of Sciences Beijing 100083 China

The preparation of high quality ZnO/Si substrates for the growth of GaN blue light emitting materials is considered. ZnO thin films have been deposited on Si (100) and Si (111) substrates by conventional magnetron sputtering. Morphology, crystallinity and c-axis preferred orientation of ZnO thin films have been investigated by transmitting electron microscopy (TEM), X-ray diffraction (XRD) and X-ray rocking curve (XRC). It is proved that the ZnO thin films have perfect structure. The full-width-at-half-maximum (FWHM) of the ZnO(002) XRC of these films is about 1°, while the minimum is 0.353°. This result is better than the minimum FWHM (about 2°) reported by other research groups. Moreover, comparison and discussion are given on film structure of ZnO/Si(100) and ZnO/Si(111).

关键词： light emitting material ZnO magnetron sputtering structure X-ray rocking curve.

On the Design of Optimal Feedback Control for Systems of Second Order

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Applied Mathematics 2010年第4期1卷 301-306页

作者： Аlexander М. Formalskii Institute of Mechanics of Moscow Lomonosov State University Michurinskii prospect

A difficult but important problem in optimal control theory is the design of an optimal feedback control, i.e., the design of an optimal control as function of the phase (state) coordinates [1,2]. This problem can be solved not often. We study here the autonomous nonlinear system of second order in general form. The constraints imposed on the control input can depend on the phase (state) coordinates of the system. The goal of the control is to maximize or minimize one phase coordinate of the considered system while other takes a prescribed in advance value. In the literature, optimal control problems for the systems of second order are most frequently associated with driving both phase coordinates to a prescribed in advance state. In this statement of the problem, the optimal control feedback can be designed only for special kind of systems. In our statement of the problem, an optimal control can be designed as function of the state coordinates for more general kind of the systems. The problem of maximization or minimization of the swing amplitude is considered explicitly as an example. Simulation results are presented.

关键词： System of Second Order Optimal Feedback Control Design Swing rocking Damping Simulation

Quantitative Evaluation of an Epitaxial Silicon-Germanium Layer on Silicon

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Microscopy Research 2015年第4期3卷 41-49页

作者： Jie-Yi Yao Kun-Lin Lin Chiung-Chih Hsu National Nano Device Laboratories Taiwan

An epitaxial SixGey layer on a silicon substrate was quantitatively evaluated using rocking curve (RC) and reciprocal space map (RSM) obtained by powder X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy (EDS) in conjunction with transmission electron microscopy (TEM), and EDS in conjunction with scanning electron microscopy (SEM). To evaluate the relative deviation of the quantitative analysis results obtained by the RC, RSM, SEM/EDS, and TEM/EDS methods, a standard sample comprising a Si0.7602Ge0.2398 layer on a Si substrate was used. The correction factor (K-factor) for each technique was determined using multiple measurements. The average and standard deviation of the atomic fraction of Ge in the Si0.7602Ge0.2398 standard sample, as obtained by the RC, RSM, TEM/EDS, and SEM/EDS methods, were 0.2463 ± 0.0016, 0.2460 ± 0.0015, 0.2350 ± 0.0156, and 0.2433 ± 0.0059, respectively. The correction factors for the RC, RSM, TEM/EDS, and SEM/EDS methods were 0.9740, 0.9740, 1.0206, and 0.9856, respectively. The SixGey layer on a silicon substrate was quantitatively evaluated using the RC, RSM, and EDS/TEM methods. The atomic fraction of Ge in the epitaxial SixGey layer, as evaluated by the RC and RSM methods, was 0.1833 ± 0.0007, 0.1792 ± 0.0001, and 0.1631 ± 0.0105, respectively. After evaluating the results of the atomic fraction of Ge in the epitaxial layer, the error was very small, i.e., less than 3%. Thus, the RC, RSM, TEM/EDS, and SEM/EDS methods are suitable for evaluating the composition of Ge in epitaxial layers. However, the thickness of the epitaxial layer, whether the layer is strained or relaxed, and whether the area detected in the TEM and SEM analyses is consistent must be considered.

关键词： Silicon-Germanium Epitaxial Layer rocking Curve Reciprocal Spacing Map TEM SEM EDS