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响应谱地震动预测方程中场地效应参数V_(S30)与场地周期的比较

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世界地震译丛 2014年第3期45卷 41-62页

作者： john x. zhao Hua x. 杨国栋郑和祥吕春来不详甘肃省地震局

最近的许多地震动预测方程(GMPE)都使用上30m土层的平均剪切波速度VS30表示场地效应。然而,在一些研究发现VS30是表征场地效应合理参数的同时,另一些研究则给出了相反的证据。本研究使用日本的大地震动数据集对这两个场地效应参数的预... 详细信息

最近的许多地震动预测方程(GMPE)都使用上30m土层的平均剪切波速度VS30表示场地效应。然而,在一些研究发现VS30是表征场地效应合理参数的同时,另一些研究则给出了相反的证据。本研究使用日本的大地震动数据集对这两个场地效应参数的预测能力进行系统的比较。采用该方法的基础是使用场地周期(TS,4倍剪切波从基岩到地表的走时)或VS30对经验模拟场地效应的标准偏差和放大比振幅进行比较。模拟的场地效应除了包括地震动预测方程的场地效应项,还特别包括KiK-net台网的地表与井下记录之间的场地放大比。就KiK-net台网数据而言,对TS>0.6s的土层场地,TS被确定是比VS30好的预测参数;而对TS<0.6s的场地,这两个参数对放大比产生了相似的变异性。在所有场地类别的多数周期上,由地震动预测方程获得的场地效应,VS30和TS在统计上相等;而在一些谱周期上,VS30产生了比TS小的变异性。KiK-net台网地表—井下记录与地震动预测方程结果的矛盾可能由地震动预测方程中包括震源变异性、路径变异性和场地变异性的大变异性所致。相比之下,KiK-net台网地表—井下数据对的变异性小多了。虽然VS30和TS对地震动预测方程的数据产生了统计上相似的标准偏差,但TS仍然获得了比VS30更好的中值放大比。

关键词：场地效应预测方程效应参数地震动周期响应谱剪切波速度场地放大

A simulation-based nonlinear site amplification model for ground-motion prediction equations in Japan

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Earthquake Engineering and Engineering Vibration 2021年第4期20卷 843-862页

作者： Ruibin Hou john x.ngquan zhao School of Civil Engineering Southwest Jiaotong UniversityChengdu 610031China Key Laboratory of Building Structural Retrofitting and Underground Space Engineering Ministry of EducationShandong Jianzhu UniversityJi′nan 250101China

In this manuscript we present a nonlinear site amplification model for ground-motion prediction equations(GMPEs)in Japan,using a site period-based site class and a site impedance ratio as site *** used a large number of shear-wave velocity profiles from the Kiban-Kyoshin network(KiK-net)and the Kyoshin network(K-NET)to construct the one-dimensional(1D)numerical *** strong-motion records from rock-sites in Japan with different earthquake categories and taken from the Pacific Earthquake Engineering Research Center dataset were used in this *** fit a set of 1D site amplification models using the spectral amplification ratios derived from 1D equivalent linear *** of site impedance ratios for both linear and nonlinear site response were included in the 1D *** 1D model could be implemented into GMPEs using a new proposed adjustment *** adjusted site amplification ratios retain the nonlinear characteristics of the 1D model for strong motions and match the linear amplification ratio in GMPE for weak *** nonlinearity of the present site model is reasonably similar to that of the historical models,and the present site model could satisfactorily capture the nonlinear site response in empirical data.

关键词： nonlinear site amplification model ground-motion prediction equations site class site impedance ratio site response analysis

Catalytic nanomotors： fabrication, mechanism, and applications

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Frontiers of Materials Science 2011年第1期5卷 25-39页

作者： john GIBBS Yiping zhao Nanoscale Science and Engineering Center Department of Physics and Astronomy The University of Georgia Athens GA 30602 USA

Catalytic nanomotors are nano-to-micrometer-sized actuators that carry an on-board catalyst and convert local chemical fuel in solution into mechanical work. The location of this catalyst as well as the geometry of the structure dictate the swimming behaviors ex.ibited. The nanomotors can occur naturally in organic molecules, combine natural and artificial parts to form hybrid nanomotors or be purely artificial. Fabrication techniques consist of template directed electroplating, lithography, physical vapor deposition, and other advanced growth methods. Various physical and chemical propulsion mechanisms have been proposed to ex.lain the motion behaviors including diffusiophoresis, bubble propulsion, interracial tension gradients, and self-electrophoresis. The control and manipulation based upon ex.ernal fields, catalytic alloys, and motion control through thermal modulation are discussed as well. Catalytic nanomotors represent an ex.iting technological challenge with the end goal being practical functional nanomachines that can perform a variety of tasks at the nanoscale.

关键词： nanomotors catalysis glancing angle deposition (GLAD) bubble propulsion self-electrophoresis

Modelling spiky acceleration response of dilative sand deposits during earthquakes with emphasis on large post-liquefaction deformation

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Earthquake Engineering and Engineering Vibration 2018年第1期17卷 125-138页

作者： Wang Gang Wei x.ng john zhao Key Laboratory of New Technology for Construction of Cities in Mountain Area Chongqing University School of Civil Engineering Chongqing University School of Civil Engineering Southwest Jiaotong University

The acceleration records at some liquefied sand deposits ex.ibit a distinctive spiky waveform, characterized by strong amplification and high-frequency components. A comprehensive constitutive model was used to analyze the mechanism of such spiky acceleration responses. An idealized single-degree-of-freedom（SDF） system was constructed, in which the force-displacement relation of the spring follows the stress-strain behavior of saturated sand during undrained shearing. The SDF system demonstrated that the spikes are directly related to the strain-hardening behavior of sand during post-liquefaction cyclic shearing. Furthermore, there ex.sts a threshold shear strain length, which is in accordance with the limited amplitude of the fluid-like shear strain generated at instantaneous zero effective stress state during the post-liquefaction stage. The spiky acceleration can only occur when the cyclic shear strain ex.eeds the threshold shear strain length. It is also revealed that the time intervals between the acceleration spikes increase gradually along with the continuation of shaking because the threshold shear strain length increases gradually and then more time is needed to generate larger shear strain to cause strain hardening. Records at the Kushiro Port site and Port Island site during past earthquakes are simulated through the fully coupled method to validate the presented mechanism.

关键词： spiky acceleration cyclic mobility post-liquefaction seismic response sand

Deformation Analysis of Micro/Nano Indentation and Diamond Grinding on Optical Glasses

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Chinese Journal of Mechanical Engineering 2012年第3期25卷 411-418页

作者： zhao Qingliang zhao Lingling GUO Bing STEPHENSIN David CORBETT john School of Mechatronics Engineering Harbin Institute of TechnologyHarbin 150001China Materials Department Cranfield UniversityCranfieldBedford MK43 OALUK School of Applied Sciences Cranfield UniversityCranfieldBedford MK43 OALUK

The previous research of precision grinding optical glasses with electrolytic in process dressing （ELID） technology mainly concentrated on the action of ELID and machining parameters when grinding, which aim at generating very ＂smoothed＂ surfaces and reducing the subsurface damage. However, when grinding spectrosil 2000 and BK7 glass assisted with ELID technology, a deeply comparative study on material removal mechanism and the wheel wear behaviors have not been given yet. In this paper, the micro/nano indentation technique is initially applied for investigating the mechanical properties of optical glasses, whose results are then refereed to evaluate the machinability. In single grit diamond scratching on glasses, the scratching traces display four kinds of scratch characteristics according to different material removal modes. In normal grinding ex.eriments, the result shows BK7 glass has a better machinability than that of spectrosil 2000, corresponding to what the micro/nano indentation vent revealed. Under the same grinding depth parameters, the smaller amplitude of acoustic emission （AE） raw signals, grinding force and grinding force ratio correspond to a better surface quality. While for these two kinds of glasses, with the increasing of grinding depth, the variation trends of the surface roughness, the force ratio, and the AE raw signals are contrary, which should be attributed to different material removal modes. Moreover, the SEM micrographs of used wheels surface indicate that diamond grains on the wheel surface after grinding BK7 glass are worn more severely than that of spectrosil 2000. The proposed research analyzes what happened in the grinding process with different material removal patterns, which can provide a basis for producing high-quality optical glasses and comprehensively evaluate the surface and subsurface integrity of optical glasses.

关键词： optical glasses micro/nano indentation single grit diamond scratching material removal mode surface integrity electrolytic in process dressing (ELID)

A probabilistic-based method to evaluate hygrothermal performance of an internally insulated brick wall

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Building Simulation 2021年第2期14卷 283-299页

作者： Jianhua zhao Jianshun Zhang john Grunewald Shuo Feng Institute of Architectural Technology&Science School of ArchitectureTianjin UniversityTianjinChina College of Mechanical&Aerospace Engineering Syracuse UniversitySyracuseUSA Institute of Building Climatology School of ArchitectureTechnische Universität DresdenDresdenGermany Qinhuangdao Municipal Bureau of Foreign Affairs and Commerce QinhuangdaoChina

Uncertainty ex.sts in many aspects of building simulation.A deterministic hygrothermal analysis may not sufficiently give a reliable guidance if a number of input variables are subject to *** this paper,a probabilistic-based method was developed to evaluate the hygrothermal performance of building *** approach accounts for the uncertainties from model inputs and propagates them to the outputs through the simulation model,thus it provides a likelihood of performance *** hypercube sampling technique,incorporated with correlation structure among the inputs,was applied to generate the random samples that follows the intrinsic *** performance of an internally insulated masonry wall was evaluated by applying the proposed approach against different *** performance,condensation and mould growth potential of the renovated wall can overall satisfy the requirements stipulated in multifold *** most influential inputs were identified by the standardized regression sensitivity analysis and partial correlation *** methods deliver the same key parameters for the single and time-dependent output variables in the case *** probabilistic method can provide a comprehensive risk analysis and support the decision-maker and engineer in the design and optimization of building components.

关键词： probabilistic approach hygrothermal performance building component uncertainty analysis sensitivity analysis

Micro/nano Indentation and Single Grit Diamond Grinding Mechanism on Ultra Pure Fused Silica

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Chinese Journal of Mechanical Engineering 2011年第6期24卷 963-970页

作者： zhao Qingliang GUO Bing STEPHENSIN David CORBETT john School of Mechatronics Engineering Harbin Institute of Technology Harbin 150001 China Materials Department Cranfield University Cranfield Bedford MK43 OAL UK School of Applied Sciences Cranfield University Cranfield Bedford MK43 OAL UK

The ex.sting research about ductile grinding of fused silica glass was mainly focused on how to carry out ductile regime material removal for generating very ＂smoothed＂ surface and investigate the machining-induced damage in the grinding in order to reduce or eliminate the subsurface *** brittle/ductile transition behavior of optical glass materials and the wear of diamond wheel are the most important factors for ductile grinding of optical *** this paper,the critical brittle/ductile depth,the influence factors on brittle/ductile transition behavior,the wear of diamond grits in diamond grinding of ultra pure fused silica（UPFS） are investigated by means of micro/nano indentation technique,as well as single grit diamond grinding on an ultra-stiff machine tool,Tetraform ＂C＂.The single grit grinding processes are in-process monitored using acoustic emission（AE） and force dynamometer *** wear of diamond grits,morphology and subsurface integrity of the machined groves are ex.mined with atomic force microscope（AFM） and scanning electron microscope（SEM）.The critical brittle/ductile depth of more than 0.5 μm is *** compared to the using roof-like grits,by using pyramidal diamonds leads to higher critical depths of scratch with identical grinding ***,the influence of grit shapes on the critical depth is not significant as *** grinding force increased linearly with depth of cut in the ductile removal regime,but in brittle removal regime,there are large fluctuations instead of forces *** SEM photographs of the cross-section profile show that the median cracks dominate the crack patterns beneath the single ***,The SEM photographs show multi worn patterns of diamond grits,indicating an inhomogeneous wear mechanism of diamond grits in grinding of fused silica with diamond grinding *** proposed research provides the basal technical theory for improving the ultra-precision grinding of UPFS.

关键词： ultra pure fused silica (UPFS) micro/nano indentation single grit diamond grinding ductile material removal subsurface integrity diamond grits wear

Historical record of effects of human activities on absolute and relative concentrations of Polycyclic aromatic hydrocarbons(PAHs) in Lake Chao,China

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Journal of Environmental Sciences 2016年第8期28卷 1-4页

作者： john P.Giesy Zhi Tang x.aoli zhao Department of Veterinary Biomedical Sciences and Tox.cology Centre University of Saskatchewan State Key Laboratory of Environmental Criteria and Risk Assessment Chinese Research Academy of Environmental Sciences

Polycyclic aromatic hydrocarbons（PAHs）are attracting concern because of their potential tox.city,posing serious threats to health of humans and ecosystems（Kim et al.,2013;zhao et al.,2016）.Generally,similar to other contaminants＇behaviors（Wu et al.,2001;Zhang et al.,2007,2008;Lu et al.,2009）,PAHs result from natural organic matter and activities of humans,the latter＇s contribution usually outweighing the inputs from other sources（Fernández et al.,2000;Srogi,2007）.

关键词： Polycyclic aromatic hydrocarbons Organic contaminants Aquatic environment Lake sediment PAHs

Temperature Dependence of Transverse Mode Evolution in Vertical Cavity Surface-Emitting Lasers

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Chinese Physics Letters 1995年第3期12卷 160-163页

作者： zhao Yi-Giang john G.McInerney Department of Physics Peking UniversityBeijing 100871 Department of Physics National University of IrelandUniversity CollegeCorkIreland

We have observed time-resolved spectra and spontaneous near-field profiles of vertical cavity surface-emitting laser,and have considered possible reasons for the origin of multiple transverse *** results show that,even under low-duty pulsed operation,the evolution of temperature profiles plays a dominant role in determing the transverse mode behaviour.

关键词： transverse Vertical cavity