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Science China(Information Sciences) 2024年

作者： Haoran WU Kaiming NIE Jiangtao XU Qinglong LIN Yingying JIAO 1.School of Microelectronics, tianjin university 2.tianjin Key Laboratory of Imaging and Sensing Microelectronic Technology

In recent years, Flash LiDAR sensors based on direct timeof-flight(DToF) have been playing an increasingly important role in various 3D imaging fields. In order to perform a histogram on the chip to reduce the data rate, it is inevitable to use a large-size histogramming time-to-digital converter(hT DC) in a Flash LiDAR sensor. However, a large-size hT DC limits the spatial resolution of the sensor.

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The mechanism of enterprise-university-esearch institute binding to promote higher education and protection measures——For example tianjin

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学周刊 2012年第23期 29-31页

作者： Xu Zheng (tianjin Polytechnic university TJPU tianjin,China)

The Mechanism of Enterprise-university-research institute (EURI) Binding is a market-oriented strategic alliance as the government and industry associations and intermediary organs for auxiliary forces complement, in which enterprises play the leading role and which combines the efforts of enterprises, universities and research institutes. It is the advanced development of enterprise- university-research institute binding cooperation. The development of technology and social economy continue to offer new challenges for higher education. Under this situation, many universities in tianjin area actively develop their superiority and cooperate with enterprise and research department, trying their best to explore various enterprise- university-research institute binding ways to quicken the pace of technology innovation and transfer in order to make the school’s track wider and wider. According to the situation of tianjin area, this text introduces the cases of mechanism of enterprise-university- research binding about this area’s universities and comes up with safeguard measures on the base of analyzing other areas’ mechanism of enterprise-university-research institute binding, combining with educational economy and management theory.

关键词： Higher Education Enterprise-university-research institute Binding Mechanism Safeguard Measure

On the composition operators on the Bloch space of several complex variables

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Science China Mathematics 2005年第Z1期48卷 392-399页

作者： ZHOU Zehua & CHE Renyu Department of Mathematics, tianjin university, tianjin 300072, China LiuHui Center for Applied Mathematics, Nankai university & tianjin university,tianjin 300072, China Department of Mathematics Tianjin University Tianjin China LiuHui Center for Applied Mathematics Nankai University & Tianjin University Tianjin China

In this paper we first look upon some known results on the composition operator as bounded or compact on the Bloch-type space in polydisk and ball, and then give a sufficient and necessary condition for the compositio... 详细信息

关键词： Bloch space, bounded symmetric domains, composition operator, bergman metric.

Inflow conditions for spatial direct numerical simulation of turbulent boundary layers

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Science China(Physics,Mechanics & Astronomy) 2008年第8期51卷 1106-1115页

作者： HUANG ZhangFeng & ZHOU Heng Department of Mechanics,tianjin university,tianjin 300072,China Liu-Hui Center of Applied Mathematics,Nankai university and tianjin university,tianjin 300072,China Department of Mechanics Tianjin University Tianjin China Liu-Hui Center of Applied Mathematics Nankai University and Tianjin University Tianjin China

The inflow conditions for spatial direct numerical simulation(SDNS) of turbulent boundary layers should reflect the characteristics of upstream turbulence,which is a puzzle. In this paper a new method is suggested,in which the flow field obtained by using temporal direct numerical simulation(TDNS) for fully developed turbulent flow(only flow field for a single moment is sufficient) can be used as the inflow of SDNS with a proper transformation. The calculation results confirm that this method is feasible and effective. It is also found that,under a proper time-space transformation,all statistics of the fully developed turbulence obtained by both temporal mode and spatial mode DNS are in excellent agreement with each other,not only qualitatively,but also quantitatively. The normal-wise distributions of mean flow profile,turbulent Mach number and the root mean square(RMS) of the fluctuations of various variables,as well as the Reynolds stresses of the fully developed turbulence obtained by using SDNS,bear similarity in nature.

关键词： inflow conditions spatial direct numerical simulation turbulent boundary layer similarity

STATISTICAL PREDICTION OF SEDIMENT TRANSPORT

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China Ocean Engineering 1987年第2期1卷 91-93页

作者： Liu Defu(tianjin university, tianjin) tianjin Univ Tianjin China Tianjin Univ Tianjin China

Based on the longshore sediment transport calculated by Bijker formula, this paper discusses the long-term distribution of sediment transport and presents formulae to statistically predict probable and most disadvantageous total quantity of sediment transport in multiple years blocked by a littoral barrier. These formulae are useful for planning and designing various types of coastal structures.

关键词： STATISTICAL PREDICTION OF SEDIMENT TRANSPORT

K-quasi-additive fuzzy integrals of set-valued mappings

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Progress in Natural Science:Materials International 2006年第2期16卷 125-132页

作者： WANG Guijun and LI Xiaoping ( School of Mathematics Science, tianjin Normal university, tianjin 300074, China School of Management, tianjin Normal university, tianjin 300074, China) School of Mathematics Science Tianjin Normal University Tianjin 300074 China School of Management Tianjin Normal University Tianjin 300074 China

We first define the quasi-addition and quasi-multiplication operations by introducing the inductive operator, and then, in the K-quasi-additive fuzzy measure space, we establish the K-quasi-additive fuzzy integral of a generally measurable set-valued mapping. Applying the integral transformation theorem, some basic properties of the K-quasi-additive fuzzy integrals with respect to this kind of set-valued mapping are studied. Finally, the generalized monotone convergence theorems of this kind of fuzzy integrals are obtained.

关键词： set-valued mapping inductive operator integrable selections K-quasi-additive fuzzy integrals.

GRAPHITE NUCLEI IN CAST IRON UNDER INOCULATION TREATMENT

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Acta Metallurgica Sinica(English Letters) 1993年第12期6卷 411-415页

作者： WAMG Chunqi YANG Jiguang tianjin university,tianjin,China associate professor,Faculty of Foundry,tianjin university.tianjin 300072,China tianjin Univ Tianjin China

Melted cast iron was inoculated by FeSi,then quenched to interrupt the dissolution, the non-metallic inclusions,in which the graphite phase was already occured,formed in the dissolution region,They dissolved into the melt soon,but the inclusions coated by graphite could exist for along *** function of inoculant is to create an undercooling solution for carbon,thereby the non-metallic inclusions in the solution may be activated as the nuclei for graphite.

关键词： inoculation cast iron dissolution region activated nuclei

A GENERAL ITERATIVE METHOD OF FIXED POINTS FOR EQUILIBRIUM PROBLEMS AND OPTIMIZATION PROBLEMS

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Journal of Systems Science & Complexity 2009年第3期22卷 503-517页

作者： Fang ZHANG·Yongfu SUDepartment of Mathematics,tianjin Polytechnic university,tianjin 300160,China. Department of Mathematics Tianjin Polytechnic University Tianjin China

The purpose of this paper is to present a general iterative scheme as below:and to prove that,if {a_n} and {r_n} satisfy appropriate conditions,then iteration sequences {x_n} and{u_n} converge strongly to a common element of the set of solutions of an equilibrium problem and theset of fixed points of a nonexpansive mapping and the set of solution of a variational inequality,***,by using the above result,we can also obtain an iterative algorithm for solution of anoptimization problem min h(x),where h(x) is a convex and lower semicontinuous functional defined on aclosed convex subset C of a Hilbert space *** results presented in this paper extend,generalize andimprove the results of Combettes and Hirstoaga,Wittmann,***,Giuseppe Marino,Hong-KunXu,and some others.

关键词：优化问题迭代方法平衡问题不动点通用希尔伯特空间变分不等式非扩张映射

Wave-packet method for instability of three-dimensionalboundary layer of swept wing

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Chinese Science Bulletin 1998年第6期43卷 461-464页

作者： ZHAO Gengfu Department of Physics, tianjin university, tianjin 300072, China Department of Physics Tianjin University Tianjin China

A wave-packet method is proposed to study evolution the behavior of disturbances in 3-D boundary layer on a swept plate. It is proved that the constant-phase lines are equivalent to the streaks observed in flow-visual... 详细信息

关键词： swept plate wave packet structure of streaks.

The improvement of turbulence modeling for the aerothermal computation of hypersonic turbulent boundary layers

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Science China(Physics,Mechanics & Astronomy) 2010年第2期53卷 369-379页

作者： DONG Ming & ZHOU Heng Department of Mechanics,tianjin university,tianjin 300072,China Department of Mechanics Tianjin University Tianjin China

The engineering computation of turbulent flows is mainly based on turbulence modeling,however,accurate aerothermal computation of hypersonic turbulent boundary layers is still a not well-solved problem. Aerothermal computation for turbulent boundary layers on a supersonic or hypersonic blunt cone with small bluntness is done firstly by using both direct numerical simulation and BL model,and seven different cases are investigated. Then the results obtained by the two methods are compared,and the reason causing the differences is found to be the incorrect assumption in the turbulence modeling that the ratio between eddy heat conductivity and eddy viscosity is constant throughout the whole boundary layer. Based on certain theoretical arguments,a method of modifying the expression of eddy heat conductivity in the region surrounding the peak location of the turbulent kinetic energy is proposed,which is verified to be effective,at least for the seven cases investigated.

关键词： hypersonic turbulent boundary layer aerothermal supersonic cone direct numerical simulation(DNS) BL model coefficient of eddy heat conductivity