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Science China(Physics,Mechanics & Astronomy) 2005年第5期48卷 614-625页

作者： HUANG Zhangfeng 1, CAO Wei 1,2.& ZHOU Heng 1,2.1. Department of Mechanics, tianjin university, tianjin 300072. China 2. Liu-Hui Center of Applied Mathematics, Nankai university and tianjin university, tianjin 300072. China 1. Department of Mechanics Tianjin University 300072 Tianjin China 2. Liu-Hui Center of Applied Mathematics Nankai University and Tianjin University 300072 Tianjin China

Temporal mode direction numerical simulation has been done for the transition of a supersonic boundary layer on a flat plate with Mach number 4.5. Analysis of the result showed that during the breakdown process in laminar-turbulent transition, the mechanism causing the mean flow profile to evolve swiftly from laminar to turbulent was that the modification of mean flow profile by the disturbances,when they became larger,led to a remarkable change of its stability characteristics. Though the most unstable T-S wave was of second mode for laminar flow, the first mode waves played the key role in the breakdown process in laminar-turbulent transition.

关键词： supersonic boundary layer, transition, breakdown.

Direct numerical simulation of a supersonic turbulent boundary layer on a flat plate and its analysis

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Science China(Physics,Mechanics & Astronomy) 2005年第5期48卷 626-640页

作者： HUANG Zhangfeng1, ZHOU Heng1,2.& LUO Jisheng1,2.1. Department of Mechanics, tianjin university, tianjin 300072. China 2. Liu-Hui Center of Applied Mathematics, Nankai university and tianjin university, tianjin 300072. China 1. Department of Mechanics Tianjin University 300072 Tianjin China 2. Liu-Hui Center of Applied Mathematics Nankai University and Tianjin University 300072 Tianjin China

Temporal mode direct numerical simulation (DNS) has been done for a supersonic turbulent boundary layer on a flat plate with Mach number 4.5. It was found that the mean flow profile, the normal-wise distribution of turbulent Mach number and the root mean square (RMS) of the fluctuations of various variables, as well as the Reynolds stresses, bore similarity in nature, when the turbulence reached a fully developed state. But the compressibility effect was strong and must be considered. The strong Reynolds analogy (SRA) and the Morkovin hypothesis were no longer valid. From the end of transition to the fully developed state of turbulence, it was in the transient period, for which the similarity did not hold.

关键词： turbulence, similarity, compressibility effect, supersonic boundary layer, direct numerical simulation.

Linguistic granular model: design and realization

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Progress in Natural Science:Materials International 2005年第8期15卷 749-756页

作者： YUE Shihong 1,2., LI Ping2.and SONG Zhihuan2.1. Institute of Industrial Process Control, Zhejiang university, Hangzhou 31002., China 2. School of Electric Engineering and Atomization, tianjin university, tianjin 300072. China) Institute of Industrial Process Control Zhejiang University Hangzhou 310027 China. School of Electric Engineering and Atomization Tianjin University Tianjin 300072 China

A new linguistic granular model is proposed and the effect of its parameters on the output is analyzed. The design of the model consists of two stages: using conditional fuzzy clustering for information granular, and integrating all information granules to final output. The integrating tool is fuzzy integral based on fuzzy measure, and the generalization of fuzzy integral increases flexibility of the linguistic granular model greatly. A heuristic algorithm to determine the parameters in the fuzzy integral is used to realize the linguistic model. Two experiments verify the feasibility of the proposed model.

关键词： linguistic model granular fuzzy clustering fuzzy integral.

Influence of p-layer on the performance of n-i-p μc-Si:H thin film solar cells

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Science China(Physics,Mechanics & Astronomy) 2010年第11期53卷 2042-2046页

作者： YUAN YuJie 1,2.ZHANG KaiLiang 1,2.WEI Zhen 1,2.& GENG XinHua 3 1 College of Electronics Information Engineering,tianjin university of {2.,tianjin 300384,China 2.tianjin Key Laboratory of Film Electronic and Communication Devices,tianjin university of {2.,tianjin 300384,China 3 Institute of Photo-Electronics Thin Film Devices and Technique,Nankai university,tianjin 300071,China 1. College of Electronics Information Engineering Tianjin University of Technology Tianjin 300384 China2. Tianjin Key Laboratory of Film Electronic and Communication Devices Tianjin University of Technology Tianjin 300384 China3. Institute of Photo-Electronics Thin Film Devices and Technique Nankai University Tianjin 300071 China

The high pressure radio frequency plasma enhanced chemical vapor deposition (RF-PECVD) process was adopted to prepare the n-i-p microcrystalline silicon solar cells,the influence of p-type layers on the performance of the solar cells was investigated,and the optimum p layer suited to the n-i-p microcrystalline silicon solar cells was *** experimental results demonstrate that the performance of the solar cells can be highly affected by the structural and optical properties of the p-layers,and the performance of solar cells can be greatly improved by optimizing p *** have achieved an initial active-area efficiency of 8.17% (V oc =0.49 V,J sc =2..9 mA/cm 2.,FF=67%) for the μc-Si:H single-junction n-i-p solar cells and an initial active-area efficiency of 10.93% (V oc =1.31 V,J sc =13.09 mA/cm 2.,FF=64%) for the a-Si:H/μc-Si:H tandem n-i-p solar cells.

关键词： microcrystalline silicon solar cells quantum confinement effect p-type layers

A study on odd-parity high-lying states of the Sm atom with three-color resonant excitation

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Science China(Physics,Mechanics & Astronomy) 2011年第6期54卷 1124-1130页

作者： LI Ming 1,2.DAI ChangJian 1,2.& XIE Jun 1,2.1 Key Laboratory of Display Materials and Photoelectric Devices,Ministry of Education,tianjin 300191,China 2.School of Science,tianjin {2. of technology,tianjin 300384,China 1. Key Laboratory of Display Materials and Photoelectric Devices Ministry of Education Tianjin 300191 China2. School of Science Tianjin University of Technology Tianjin 300384 China

The odd-parity high-lying states of the Sm atom are investigated systematically by a three-color resonant excitation scheme with two different excitation *** two intermediate states,4f 6 6s7s 7 F 0 and 4f 6 6s7s 7 F 1 are employed for paths I and II,***-seven bound states are detected with paths I and II in the energy range between 44188 and 45515 cm 1,while 64 autoionizing states are found in the energy range from 4552. to 45761 cm *** only the level energies of all observed states,but also the line widths of autoionizing states are *** possible impact of configuration interaction on the line shape of autoionizing states is also *** addition,the total angular momentum is assigned uniquely to most of the states,whereas the information about the relative line intensity of all states is also presented.

关键词： high-lying states odd-parity the Sm atom resonant excitation

Automorphisms with order three of affine Lie algebras

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Chinese Science Bulletin 1998年第21期43卷 1793-1798页

作者： JIN Quanqin 1,2.and HOU Zixin 2.1. Department of Mathematics, Hebei university, Baoding 071002. China 2. Department of Mathematics, Nankai university, {2. 300071, China Department of Mathematics Hebei University Baoding China Department of Mathematics Nankai University Tianjin China

Some properties of automorphisms of affine Lie algebras are presented. Automorphisms with order three are classified up to conjugacy, and their fixed point sets are also computed. As a corollary, it is proved that two... 详细信息

关键词： affine Lie algebra automorphism of order three first (second) kind of automorphism.

Converse Result on Szász-Type Operators

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Transactions of tianjin university 2010年第2期16卷 135-137页

作者：宋占杰 School of Sciences Tianjin University Institute of TV and Image Information Tianjin University

Szasz-type operators can be constructed by a Poisson process. The purpose of this paper is to derive the converse result in connection with Szasz-type operators by Steckin-Marchaud-type inequalities and new Ditzian mo... 详细信息

关键词： Sz^isz-type operators Poisson process Steckin-Marchaud-type inequalities continuity approximation

Search for B_c (ns) via the B_c (ns) → B_c (ms) π^+ π^- transition at LHCb and Z^0 factory

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Science China(Physics,Mechanics & Astronomy) 2010年第11期53卷 2019-2024页

作者： KE HongWei 1 & LI XueQian 2.1 School of Science,tianjin university,tianjin 300072.China 2.School of Physics,Nankai university,tianjin 300071,China 1. School of Science Tianjin University Tianjin 300072 China2. School of Physics Nankai University Tianjin 300071 China

It is interesting to study the characteristics of the whole family of B c which contains two different heavy *** and the proposed Z 0 factory provide an opportunity because a large database of the B c family will be achieved.B c and its excited states can be identified via their decay *** suggested by experimentalists,B-c (ns) → B c +γ is not easy to be clearly measured,instead,the trajectories of π + and π- occurring in the decay of B c (ns) → B c (ms) + π + π( n > m ) can be unambiguously identified,thus the measurement seems easier and more reliable;therefore this mode is more favorable at the early running stage of LHCb and the proposed Z 0 *** this work,we calculate the rate of B c (ns) → B c (ms) + π + π-in terms of the QCD multipole-expansion and the numerical results indicate that the experimental measurements with the luminosity of LHC and Z 0 factory are feasible.

关键词： meson hadronic decay QCD multipole-expansion

Suggestions of Transfer Rural Surplus Labor with the County Economy Development

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Suggestions of Transfer Rural Surplus Labor with the County ...

Large Eddy Simulation of New Vortex Generator Enhancing Heat Exchange of Solar Energy

Integrative Research of the Beijing-tianjin-Langfang Based on Regional Economic Development--International Conference of Lang Fang Economy and Industrial Clusters

作者： Hao Zhigong~1 Dong shuisheng~2.1 heibei university Of {2. Of Langfang Department,Langfang Hebei, 065000,China 2.heibei university of technology,beichen tianjin,300401,China

＜正＞Along with the mechanization of agricultural production, industrialization and the operation of the continuous development of rural economy,a large number of idle rural labor *** order to make full use of our labor resources,improve the rural economic development level of economy and improving farmers’ living conditions,the transfer of rural surplus labor force has become an important work.

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湖南大学学报（自然科学版） 2009年第S1期36卷 186-192页

作者： WEN Juan,YANG Li,QI Cheng-ying(Department of Thermal Power Engineering,Hebei university of technology,{2. 300401,China) Department of Thermal Power Engineering Hebei University of Technology Tianjin 300401 China

This paper put forward a new-type vortex generator enhancing heat exchange of solar air-drier and air-heater on the gas side,and investigated the mechanism of heat transfer enhancement and drag reduction by the influence of vortex generators on the coherent structure of turbulent boundary *** flow and heat transfer characteristics of rectangle channel with bevel-cut half-elliptical column vortex generators were obtained using large eddy simulation(LES)and the hydromechanics software *** instantaneous properties of velocity,temperature and pressure in channel were *** coherent structure of turbulent boundary layer flow was showed,and the characteristic of vortex induced by inclined-cut semi-ellipse vortex generator and its influence on turbulent coherent structure were *** the effect mechanism of turbulent coherent structure on flow field,pressure field and temperature field was *** on the results,the heat transfer coefficient and drag reduction of the new vortex generator with different pitch angles were ***,the coherent effects of the increased wall heat transfer and the decreased skin friction do not satisfy the Reynolds *** turbulent coherent structure can be controlled through the geometry of the vortex generator,so the heat transfer and drag reduction can also be *** we can seek suitable form of vortex generator and structure parameters,in order to achieve the enhanced heat transfer and flow of drag reduction in the solar air-heater and solar air-drier.

关键词： large eddy simulation vortex generator bevel-cut half-elliptical column coherent structure heat transfer enhancement