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Zonal Flows and Geodesic Acoustic Mode Oscillations in tokamaks and Helical Systems

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Plasma Science and technology 2006年第1期8卷 105-109页

作者： t. WAtARI y. HAMADA A. NISHIZAWA t. NOtAKE N. tAKEUCHI National Institute for Fusion Science 322-6 Oroshi-cho Toki-city Gifu Japan Ariake National College of technology 150 Higashihagio-Machi Omuta Fukuoka Japan

this paper reviews the theoretical foundations of zonal flow, putting emphasis on the linear response function of plasma to the external flow drive. An extension of the theory is made in order to apply it to helical systems and to study the properties of the zonal flow in the low frequency range. Further refinement of the theory is made incorporating the orbital effects of particles more precisely, and the role of neoclassical polarization current is identified.

关键词： zonal flow geodesic acousti mode finite orbit effect coupling to ion acoustic mode

tHERMAL PERFORMANCE OF FELt tyPE VEGEtAtED FACADE SyStEMS IN A tEMPERAtE CLIMAtE DURING HEAtING AND COOLING PERIODS

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Journal of Green Building 2021年第4期16卷 199-225页

作者： Elif Özer yüksel Nil türkeri Department of Architecture Faculty of ArchitectureGebze Technical UniversityKocaeliTurkey Department of Architecture Faculty of Architectureİstanbul Technical UniversityİstanbulTurkey

Using vegetated facade systems(VFS)as a sustainable solution for existing and new buildings and evaluating thermal performance of these sytems are not a new ***,there is a gap in literature about measuring thermal performance of VFS applied on an insulated ***,in the research literature,there are few studies measuring thermal performance of felt type VFS in temperate climates,and data about the thermal performance of VFS during winter periods is still ***,the aim of the present study is to measure the thermal performance of a felt type VFS applied on a thermal insulated existing wall that us located in Kocaeli,turkey,under Csa climate conditions during heating and cooling *** results indicate that the felt type VFS acts as a shading device and has a positive contribution to the thermal performance of building walls during a cooling *** daytime when there is a high amount of solar radiation,felt type VFS decreased exterior surface temperatures of the insulated existing wall by a maximum of 24.4℃,32.2℃ and 37.2℃,in spring,summer and fall periods,***,indoor air temperatures of the vegetated facade were lower than indoor air temperatures of the reference facade with the maximum difference of 1.8℃ during the cooling ***,test results indicate that the vegetated facade never dropped to below 0℃ while exterior surface temperatures of the reference facade dropped below 0℃ at nighttime in the winter ***,it can be claimed that the felt type VFS behaves as a thermal buffer and enhances the thermal performance of the exterior wall of the existing building during heating periods at *** a conclusion,although differences between exterior surface temperatures of vegetated and reference walls were high,differences between interior surface temperatures of vegetated and reference walls were not *** is due to the fact that the existing building exterior wall assembly includes 5 cm thickne

关键词： living walls felt type vegetation facade systems sustainability field measurements thermal performance surface temperature

Mining fine-grained sequential travel patterns from social geo-tagged photos

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Frontiers of Computer Science 2018年第6期12卷 1255-1257页

作者： thanh-Hieu BUI Seong-bae PARK Institute of Research and Development Duy Tan UniversityDa Nang 550000Vietnam Department of Computer Science and Engineering Kyung Hee UniversityYongin 17104Korea

A huge amount of geo-tagged photos that contains broad knowledge about travel behaviors of human is generated and posted on social photo-sharing sites. In literature, many studies about mining travel patterns from geo-tagged social photos have been proposed. However, the existing studies lack of a comprehensive system to mine fine-grained travel patterns by utilizing extensions of sequential pattern mining. We consider the following questions for San Francisco City, CA, USA: 1) What are the popular travel routes for tourists if they have only four hours or eight hours for visiting? 2) Which POIs do international tourists prefer to visit after visiting Golden Gate Bridge? 3) Are there any differences in travel behavior between American tourists and international tourists, between male American tourists and female American tourists, between male international tourists and female international tourists? to address these questions, we define and implement a novel framework to mine fine-grained travel patterns from geo-tagged photos of a tourist destination.

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GRID GENERAtION AND NUMERICAL SIMULAtION OF 2-D RIVER FLOW

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Journal of Hydrodynamics 2001年第2期13卷 50-54页

作者： Zhao, M.D. Li, y.t. Dept. of River Eng. Wuhan Univ. Wuhan 430072 China

this paper presents new weighting functions in grid generation and new discretizing scheme of momentum equations in numerical simulation of river flow. By using the new weighting functions, the curvilinear grid could be concentrated as desired near the assigned points or lines in physical plane. By using the new discretizing scheme, the difficulties caused by movable boundary and dry riverbed can be overcome. As an application, the flow in the Wuhan Section of yangtze River is simulated. the computational results are in good agreement with the measured results. the new method is applicable to the numerical simulation of 2-D river flow with irregular region and moveable boundary.

关键词： Computer simulation Flow of fluids Mathematical models Poisson equation two dimensional

EXPERIMENt AND SIMULAtION FOR tHICK-PLAtE BENDINGBy HIGH FREQUENCy INDUCtOR

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Acta Metallurgica Sinica(English Letters) 1998年第6期11卷 449-455页

作者： S.Imatani y.Okuno t.Inoue Kyoto Univ Kyoto Japan

In order to produce thick plates with complicated curved surface, a prototype bending machine by the use of high frequency inductor was developed. the bending mechanism is based on the localized stresses which are induced from the difference of temperature in thickness by the high frequency inductor. the operating speed and the thickness of plate were examined from the experiment, and the variation of the temperature was measured. Finite element analysis was carried out in the second part based on the experimentally obtained temperature distribution. the so-called Mindlin plate element was used in order to perform the simulation efficiently. the strategy to produce such curved surface in the practical process was discussed and further perspective of the production system was described. (Edited author abstract) 6 Refs.

关键词： plate bending high frequency inductor die-less forming thermoelasto-plastic deformation finite element method

A correlation between pulse diagnosis of human body and health monitoring of structures

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Earthquake Engineering and Engineering Vibration 2004年第1期3卷 117-125页

作者： C.C.Chang Henry t.y.yang Department of Civil Engineering Hong Kong University of Science and TechnologyHong Kong Department of Mechanical and Environmental EngineeringUniversity of California Department of Mechanical and Environmental Engineering University of California

the concept of health monitoring is a key aspect of the field of medicine that has been practiced for a long time. A commonly used diagnostic and health monitoring practice is pulse diagnosis, which can be traced back approximately five thousand years in the recorded history of China. With advances in the development of modern technology, the concept of health monitoring of a variety of engineering structures in several applications has begun to attract widespread attention. Of particular interest in this study is the health monitoring of civil structures. It seem natural, and even beneficial, that these two health-monitoring methods, one as applies to the human body and the other to civil structures, should be analyzed and compared. In this paper, the basic concepts and theories of the two monitoring methods are first discussed. Similarities are then summarized and commented upon. It is hoped that this correlation analysis may help provide structural engineers with some insights into the intrinsic concept of using pulse diagnosis in human health monitoring, which may of be some benefit in the development of modern structural health monitoring methods.

关键词： human health monitoring pulse diagnosis structural health monitoring vibration-based techniques local detection techniques

Microstructure and Mechanical Property of Ni Metal treated by Surface Mechanical Attrition

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材料热处理学报 2004年第5期25卷 161-164页

作者： t.y. Hsu School of Materials Science and Engineering Shanghai Jiao Tong University Shanghai 200030China

A nanostructured surface layer can be formed in Ni metal treated by surface mechanical attrition (SMA). the microstructure was investigated by using optical microscope, X-ray diffractometer and transmission electron microscope, respectively. Mechanical property measurements indicate that the yield strength of the surface layer raises significantly while the tensile strength somewhat changes and the elongation percentage reduces severely compared with that of the inside layer. Meanwhile, yield-drop-like phenomenon occurs in the surface layer after SMA treatment. In order to compare the mechanical behavior of nanostructured materials with two phases, Fe-30Ni nanostructured alloy was also investigated.

关键词：显微结构表面层机械性能表面损耗镍合金

Effect of ultrasonic stirring on temperature distribution and grain refinement in Al-1.65%Si alloy melt

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中国有色金属学会会刊：英文版 2007年第4期17卷 691-697页

作者：李军文 t. Momono 付莹贾征 y. tayu College of Material and Chemical Engineering Liaoning University of Technology Faculty of Materials Science and Engineering Muro ran Institute of Technology Faculty of Materials Science and Engineering Muroran Institute of Technology

A series of experiments were conducted for Al-1.65%Si (mass fraction) alloy melt to study the formation of grain refining structure with ultrasonic stirring. the cooling curves of ingots with ultrasonic were measured and compared with those without ultrasonic. At the same time, the effect of the time of ultrasonic stirring on solidification structure of ingots was investigated. the influence of ultrasonic on the grain-refining efficiency of ingots was analyzed. In order to well understand the melts behavior under ultrasonic, by using ammonium chloride solution, the simulation experiment was carried out and the temperature distribution in ingot with or without ultrasonic was compared. the results indicate that the ultrasonic reduces the temperature inhomogeneity of melt, i.e. the ultrasonic helps to homogenize the melt temperature. the effect of stirring and heat generation in ingot start to occur with increasing the time of ultrasonic stirring.

关键词：合金熔化铝硅合金温度分布铸块晶粒细化

Frequency equations of nonlocal elastic micro/nanobeams with the consideration of the surface effects

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Applied Mathematics and Mechanics(English Edition) 2018年第8期39卷 1089-1102页

作者： H.S.ZHAO y.ZHANG S.t.LIE School of Civil and Environmental Engineering Nanyang Technological University

A nonlocal elastic micro/nanobeam is theoretically modeled with the consideration of the surface elasticity, the residual surface stress, and the rotatory inertia,in which the nonlocal and surface effects are considered. three types of boundary conditions, i.e., hinged-hinged, clamped-clamped, and clamped-hinged ends, are examined. For a hinged-hinged beam, an exact and explicit natural frequency equation is derived based on the established mathematical model. the Fredholm integral equation is adopted to deduce the approximate fundamental frequency equations for the clamped-clamped and clamped-hinged beams. In sum, the explicit frequency equations for the micro/nanobeam under three types of boundary conditions are proposed to reveal the dependence of the natural frequency on the effects of the nonlocal elasticity, the surface elasticity, the residual surface stress, and the rotatory inertia, providing a more convenient means in comparison with numerical computations.

关键词： Fredholm integral equation micro/nanobeam natural frequency nonlocal elasticity surface effect