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Observation of the Turbulent Burst near ASheared Air-Water Interface

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communications in Nonlinear Science and Numerical Simulation 1999年第2期4卷 94-99页

作者： Shuangfeng WANG Fu JIA Zhennan NIU Zhangzhi WU(Institute of Mechanics, Chinese Academy of Sciences, beijing 100080, china)(State Key Laboratory for Turbulence Research, Peking university, beijing 100871,china) Institute of Mechanics Chinese Academy of Sciences Beijing 100080 China

The turbulent burst under a sheared air-water interface was experimentally investigated using hydrogen bubble visualization technique. The surface shear wasimposed by an airflow over the water flow which was kept free from surface waves. Resultsshow that the wind shear has the main influence on the bursting events. At relativelyhigh shear rates, the flow near the interface is dominated primarily by intermittent bursting events. The general features of bursting processes are described in some detail. Theobserved bursting events show qualitative similarities with those occurring in near-wallturbulence. However, a few distinctive phenomena were also observed, including the existence of vertical vortices and thickening process of the boundary layer, which appear tobe associated with the Characteristics of air-water interface.

关键词： air-water interface turbulent burst flow-visualization

A Series of Soliton-like and Double-like Periodic Solutions of a (2+1)-Dimensional Asymmetric Nizhnik-Novikov-Vesselov Equation

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communications in Theoretical Physics 2004年第11期42卷 655-660页

作者： CHEN Yong,~(1,3,4, WANG Qi~(2,4) LI Biao~(2,4) ~1Department of Mathematics,Ningbo university,Ningbo 315211,china ~2Department of Applied Mathematics,Dalian university of Technology,Dalian 116024,china ~3Department of Physics,Shanghai Jiao Tong university,Shanghai 200030,china ~4Key Laboratory of Mathematics Mechanization~ the Chinese Academy of Sciences,beijing 100080,china Department of Mathematics Ningbo University Ningbo 315211 China Department of Physics Shanghai Jiao Tong University Shanghai 200030 China Key Laboratory of Mathematics Mechanization the Chinese Academy of Sciences Beijing 100080 China Department of Applied Mathematics Dalian University of Technology Dalian 116024 China

We generalize the algebraic method presented by Fan [***.A:***.36 (2003) 7009)] to uniformlyconstruct a series of soliton-like solutions and double-llke periodic solutions for nonlinear partial differential equations(NPDE),As an application of the method,we choose a (2+1)-dimensional asymmetric Nizhnik-Novikov-Vesselov equa-tion and successfully construct new and more general solutions including a series of nontraveling wave and coefficientfunctions’ soliton-like solutions,double-like periodic and trigonometric-like function solutions.

关键词： symbolic computation soliton-like solution Weierstrass and Jacobi elliptic functions periodic solution

Fractal Characteristics of Round Jets in Steady Crossflow

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communications in Nonlinear Science and Numerical Simulation 1998年第3期3卷 183-186页

作者： Yuhang LI Chaoquan CHEN and Chunbo JIANG(Hydraulic Department, Tsinghua university, beijing 100084, china) Hydraulic Department Tsinghua University Beijing 100084 China

The fractal dimensions of turbulent round jets in steady crossflow has beenanalyzed by using planar laser-induced fluorescence (PLIF) method. The relation betweenthe fractal dimension and the momentum ratio, the variation of the fractal dimension withthe elevation of jet and the dilution have been investigated. The comparison of the fractalcharacteristics between the multiple jets and the signal jet has been carried out.

关键词： steady crossflow turbulent jet measurement of fractal dimension

Multi-layer network architecture in support of end-to-end transparent optical connectivities

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Science china(Information Sciences) 2011年第3期54卷 674-682页

作者： GUO HongXiang , WU Jian, HONG Xiao Bin & LIN Jin Tong Key Laboratory of Information Photonics and Optical communications, Ministry of Education, beijing university of Posts and Telecommunications, beijing 100876, china Key Laboratory of Information Photonics and Optical communications Ministry of Education Beijing University of Posts and Telecommunications Beijing China

In order to effectively accommodate a wide variety of emerging and future applications with diverse requirements, an intelligent optical network capable of the rapid and resilient delivery of on-demand transparent transmission capacity is required. This paper investigates a multi-layer network architecture where a generalized multiple protocol label switching (GMPLS) controlled transparent wavelength switched optical network (WSON), as the transport core, collaborates with multiple client optical burst switching (OBS) networks distributed at the edge. Dynamic interworking mechanism as well as the related signaling/routing protocol ex- tensions for multi-QoS burst streams transmission among different OBS domains are proposed so as to provision an end-to-end (e2e) transparent optical connectivity with on-demand bandwidth to end-users. Moreover, the survivability of this transparent optical connectivity is also addressed. To validate the feasibility of this architecture, an integrated OBS/WSON network testbed was constructed, and stable e2e transparent connectivities were successfully demonstrated for an efficient multi-QoS burst streams transmission.

关键词： multi-layer network transparent optical network OBS WSON GMPLS

Dynamic call and connection admission control in automatically switched optical network for grid computing applications

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Science china(Information Sciences) 2012年第2期55卷 419-432页

作者： LIU Lei,GUO HongXiang,HONG XiaoBin,WU Jian & LIN JinTong Key Laboratory of Information Photonics and Optical communications,Ministry of Education,beijing university of Posts and Telecommunications,beijing 100876,china Key Laboratory of Information Photonics and Optical communications Ministry of Education Beijing University of Posts and Telecommunications Beijing China

In recent years,Grid computing applications are becoming more and more important to the scientific and business communities and are likely to open to the consumer market and widely develop in the near future,which is a great challenge brought by the potentially large number of Grid users(perhaps millions)and high frequency of their job *** switched optical network(ASON),which is a promising high capacity intelligent transport network infrastructure,has been already deployed in the world and regarded as a promising solution to foster the expansion of Grid computing from local area networks to wide area ***,by theoretical analysis and simulative evaluation of Grid job blocking in the distributed call and connection setup process of ASON,this paper verifies that ASON and the conventional admission control mechanism confront a problem in supporting future large-scale Grid *** order to address this issue,a novel dynamic call and connection admission control(DCCAC)scheme is proposed to improve the network performance and guarantee quality of service(QoS)of Grid *** scheme is applicable with complete network information,no network information and partial network *** results show that the DCCAC scheme can improve the efficiency of the network to a great ***,all the analysis and algorithms in this paper are based on ITU-T ASON recommendations,which make the DCCAC scheme more applicable in network engineering for future Grid computing.

关键词： automatically switched optical network(ASON) Grid computing blocking probability call admission control connection admission control

Novel THP algorithms with minimum BER criterion for MIMO broadcast communications

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The Journal of china Universities of Posts and Telecommunications 2009年第4期16卷 71-77页

作者： YUN Xiang,L Tie-jun School of Information and Communication Engineering,beijing university of Posts and Telecommunications,beijing 100876,china School of Information and Communication Engineering Beijing University of Posts and Telecommunications Beijing 100876 China

In this article, two novel Tomlinson-Harashima precoding （THP） algorithms are proposed at the downlink broadcast channel of multi-user multiple-input multiple-output （MIMO） systems. The optimality criterion is the minimization of the bit error rate （BER） at the receiver with a constraint on the overall transmitted power. In these algorithms, transmit power allocation （TPA） matrix is introduced to the traditional THP algorithms as part of the precoding matrix. This leads to a power loading operation based on substreams signal to interference-plus-noise ratio （SINR） and results in improvement of the error rate performance compared with traditional THP algorithms. When the precoding loss factor is considered, further performance improvement is achieved by the enhanced algorithm.

关键词： MIMO system THP minimum bit-error rate (MBER) broadcast communication

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Calculation of valence band structures of InAs/GaAs quantum ring and quantum dot:using numerical Fourier transform method

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The Journal of china Universities of Posts and Telecommunications 2010年第1期17卷 106-110页

作者： JIA Bo-yong,YU Zhong-yuan,LIU Yu-min,TIAN Hong-da Key Laboratory of Information Photonics and Optical communications,Ministry of Education,beijing university of Posts and Telecommunications,beijing 100876,china Key Laboratory of Information Photonics and Optical communications Ministry of Education Beijing University of Posts and Telecommunications Beijing 100876 China

This article puts forward a new method in calculating the band structures of low-dimensional semiconductor structures. In this study, the valence band structures of InAs/GaAs quantum ring and lens-shaped quantum dot are calculated with four-band model, in the framework of effective-mass envelope function theory. To determine the Hamiltonian matrix elements, this article develops the numerical Fourier transform method instead of the widely used analytical integral method. The valence band mixing is considered. The hole energy levels change dramatically with the geometrical parameters of the quantum ring and quantum dot. It is demonstrated that numerical Fourier transform method can be adopted in low-dimensional structures with any shape. The results of Fourier transform method are consistent with the ones of analytical integral in literature; and they are helpful for studying and fabricating optoelectronic devices.

关键词： valence band structures quantum ring quantum dot numerical Fourier transform

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Single rub-impacting periodic motions of a rigid constrained rotor system

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communications in Nonlinear Science and Numerical Simulation 2000年第4期5卷 158-161页

作者： Qunhong LI and Qishao LU (School of Science, beijing university of Aeronautics and Astronautics, beijing 100082, china) (Received September 25, 2000) School of Science Beijing University of Aeronautics and Astronautics Beijing 100083 China

This paper discusses the existence of single rub-impacting period-n motions for a kind of rotor systems with rigid constraints. The ranges of parameters for period-2 motions are also given. An example of this method i... 详细信息

关键词： rotor system rod constraint rub-impacting mapping periodic motion\

Non-existence of positive radial solutions for a class of quasilinear elliptic system

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communications in Nonlinear Science and Numerical Simulation 2000年第4期5卷 184-187页

作者： Zuodong YANG and Qishao LU (College of Science, beijing university of Aeronautics and Astronautics, beijing 100083, china) (Received October 8, 2000) College of Science Beijing Univercity of Aeronautics and Astronautics Beijing 100083 China

In this paper, our main purpose is to establish some nonexistence results of positive radial solutions to the quasilinear ordinary differential equation system. The main results of the present paper are new and extend... 详细信息

关键词： quasilinear elliptic system Dirichlet problem positive solutions|