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Bionic Design and Finite Element Analysis of Elbow in Ice Transportation Cooling System

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Journal of Bionic Engineering 2010年第3期7卷 301-306页

作者： Dejun Miao~(1,2), Xiuhua Sui~3, Linjing Xiao~3 1. Key Laboratory of Mine Hazard Prevention and Control (Ministry of Education, china), Shandong university of science and technology, qingdao 266510, P. R. china 2. School of Architecture, Tsinghua university, Beijing 100084, P. R. china 3. college of Mechanical and Electronic Engineering, Shandong university of science and technology, qingdao 266510, P. R. china Key Laboratory of Mine Hazard Prevention and Control (Ministry of Education China) Shandong University of Science and Technology Qingdao P. R. China School of Architecture Tsinghua University Beijing P. R. China college of Mechanical and Electronic Engineering Shandong University of Science and Technology Qingdao P. R. China

With the increase in mining depth, mine heat harm has appeared to be more prominent. The mine heat harm could be resolvedor reduced by ice refrigeration. Thus, ice transportation through pipeline becomes a critical problem; typically flowresistance occurs in the elbow. In the present study, according to the analysis of the surface morphology of fish scale, abiomimetic functional surface structure for the interior wall of elbow is designed. Based on the theory of liquid-solid two phaseflow, a CFD numerical simulation of ice-water mixture flowing through the elbow is carried out using finite element *** experiments of pressure drop and flow resistance for both bionic and common elbows are conducted to test theeffect of the bionic elbow on flow resistance reduction. It is found that with the increase in the ice mass fraction in the ice-watermixture, the effect of bionic elbow on resistance reduction becomes more obvious.

关键词： bionic elbow two phase flow ice transportation flow resistance reduction pressure loss

THE LIMITING CASE OF THIELE'S INTERPOLATING CONTINUED FRACTION EXPANSION

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Journal of Computational Mathematics 2001年第4期19卷 433-444页

作者： Jie-qing Tan (Institute of Applied Mathematics, college of science and CAD/CG Division college of Computer & information Hefei, university of technology, Hefei 230009, china) 中国科学技术大学安徽合肥 230009

By means of the determinantal formulae for inverse and reciprocal differences with coincident data points, the limiting case of Thiele's interpolating continued fraction expansion is studied in this paper and given numerical example shows that the limiting Thiele's continued fraction expansion can be determined once for all instead of carrying out computations for each step to obtain each convergent as done in [3].

关键词： Continued fraction Inverse difference Reciprocal difference Expansion.

Synchronization of Digital Chaos in Secure Communication Systems

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Journal of university of science and technology Beijing 2001年第4期8卷 299-305页

作者： Geng Zhao, Deling Zheng, ShaojunHuang 1)college of Electric science and technology Beijing. Beijing 100070, china 2)information Engineering School, university of science and technology Beijing. Beijing 100083, china college of Electric science and technology Beijing Beijing 100070 China information Engineering School University of Science and Technology Beijing Beijing 100083 China

The theories of synchronization based on secure communications using digital chaos are presented. A new synchronous method-cycles-interval Pulse drive is developed and realized. Experimental results show it is available, and in order to reduce synchronous noise, a method using model references solves the ratio of signal power to noise power, so the secure communication system can be realized.

关键词： digital chaotic synchronization cycles-interval pulses drive synchronous noise model reference

Fuzzy tolerance quotient spaces and fuzzy subsets

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science china(information sciences) 2010年第4期53卷 704-714页

作者： ZHANG Ling1 & ZHANG Bo2,3,4* 1Computer science & technology college, Anhui university, Anhui 230039, china 2State Key Laboratory of Intelligent technology and Systems, Beijing 100084, china 3Tsinghua National Laboratory of information science & technology, Beijing 100084, china 4information science & technology college, Computer science & technology Department, Tsinghua university, Beijing 100084, china Computer science & technology college Anhui University State Key Laboratory of Intelligent technology and Systems Tsinghua National Laboratory of information science & technology information science & technology college Computer Science & Technology

The structure and characteristic of fuzzy subsets are discussed by using the concepts of granulation and hierarchy in quotient space theory. First, the equivalence relation based quotient space theory is extended to the fuzzy tolerance relation. Second, the isomorphism and its discriminant of fuzzy tolerance relations are discussed. Finally, by using the fuzzy tolerance relation to define the fuzzy subset, its properties are addressed. The main results are given below: (1) several equivalent statements of fuzzy tolerance relations; (2) the definition of isomorphism of fuzzy tolerance relations; (3) the isomorphic discriminant of fuzzy tolerance relations; (4) the definition and properties of fuzzy subsets based on the fuzzy tolerance relations; and (5) the necessary and sufficient condition of the isomorphism of fuzzy subsets. These results will help us further comprehend the concepts of fuzzy tolerance relations and fuzzy subsets.

关键词： Fuzzy tolerance relation quotient space isomorphism fuzzy subset

Research into a theoretical mode of coherent structures in the wall region of a turbulent boundary layer induced by a wall local disturbance

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Progress in Natural science:Materials International 2009年第9期19卷 1119-1124页

作者： Changgen Lua,*, Qinjuan Qi b a college of Atmospheric sciences, Nanjing university of information science & technology, Nanjing 210044, china b college of Public Management, Nanjing university of information science & technology, Nanjing 210044, china college of Atmospheric sciences Nanjing University of Information Science & Technology Nanjing 210044 China college of Public Management Nanjing University of Information Science & Technology Nanjing 210044 China

The idea of applying direct numerical simulation (DNS), a theoretical mode of coherent structures in the wall region of a turbulent boundary layer, has been discussed in the literature. The various aspects of the formation mechanism of the coherent structures agree well with both DNS and experimental results. In addition, a close relationship has been found between the evolutional characteristics and factors such as the magnitude and structural distribution of the wall local impulse disturbance, and the amount of energy a local disturbance introduces into the wall region. Moreover, these parameters play key roles in the formation of coherent structures near the wall region of a turbulent boundary layer. Therefore, the wall local impulse disturbance provides a theoretical model for triggering the formation of coherent structures in the wall region of a turbulent boundary layer.

关键词： Turbulent boundary layer Wall region Coherent structure Local disturbance

Experimental study of interband and intraband crosstalk in WDM networks

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Optoelectronics Letters 2008年第1期4卷 42-44页

作者： GUAN Ai-hong and WANG Yu-hua college of information science and technology, Henan university of technology, Zhengzhou 450001,china college of information science and technology Henan University of Technology Zhengzhou 450001 China

The impacts of interband and intraband crosstalk are studied and compared experimentally. Results show that interband crosstalk can be removed with narrow-band filters and has no influence on signal. Intraband crosstalk will result in signal eye diagram close and BER increasing. When the polarization states of signal and crosstalk align, intraband crosstalk seriously decreases signal quality. But when they misalign, it has little influence. Coherent and incoherent crosstalk are studied experimentally. Results show that coherent crosstalk is less harmful to system performance than incoherent crosstalk.

关键词：光纤通信波长分组复用网络串话干扰实验研究

Sufficient and necessary conditions for Lyapunov stability of Lorenz system and their application

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science china(information sciences) 2010年第8期53卷 1574-1583页

作者： LUO Qi 1 , LIAO XiaoXin 2 & ZENG ZhiGang 2 1 college of information and Control, Nanjing university of information science and technology, Nanjing 210044, china 2 Department of Control science and Engineering, Huazhong university of science and technology, Image Processing and Intelligent Control Key Laboratory of Education Ministry of china, Wuhan 430074, china college of information and Control Nanjing University of Information Science and Technology Department of Control science and Engineering Huazhong University of Science and Technology Image Processing and Intelligent Control Key Laboratory of Educatio

The sufficient and necessary conditions for Lyapunov stability of the zero equilibrium point of Lorenz system are discussed, and some brief criteria are presented for globally exponential stability, globally asymptotical stability and instability. Furthermore, the behavior of the non-zero equilibrium point of Lorenz system is also investigated, and several sufficient and necessary conditions are provided for locally exponential stability and instability. The established theorems in this paper develop and extend the existing achievements on Lyapunov stability of Lorenz system. In conclusion, by applying the obtained results, some less conservative feedback-control laws are derived to guarantee the globally exponential stability of the chaos control of Chen system, Lu¨ system, Yang-Chen system and Yu-Xia Li system.

关键词： Lorenz system Lyapunov stability sufficient and necessary condition bifurcation values globally exponential synchronization

Disturbance evolution and the nonlinear stability to the basic flows for two-dimensional quasi-geostrophic motion

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Chinese science Bulletin 1999年第13期44卷 1179-1184页

作者： SONG Shiji and LIU QinyuWeihai college , Harbin Institute of technology , Weihai 264209, china Institute of Physical Oceanography , Ocean university of qingdao , qingdao 266003 , china Weihai college Harbin Institute of Technology Weihai China Institute of Physical Oceanography Ocean University of Qingdao Qingdao China

The status of disturbances of both initial values and parameters in the models is further investigated, the exact explicit estimates on the disturbance energy and disturbance potential enstrophy are given; and while the initial disturbance fields rely only on the initial disturbance potential enstrophy, initial disturbance velocity circulation along the boundary, disturbance parameters, and the nonlinear stability criteria paralleling to Arnold’s second theorem are obtained, and the main results of Mu are generalized.

关键词： two-dimensional quasi-geostrophic motion disturbances of both initial values and parameters stability.

Representation and Adaptive Transformation of Reusable Software Components

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Wuhan university Journal of Natural sciences 2001年第Z1期6卷 298-303页

作者： Xu Zheng quan, Palakiyem Wallah college of Computer science and technology,Huazhong university of science and technology, Wuhan 430074, china college of Computer science and technology Huazhong University of Science and Technology Wuhan 430074 China

The key ingredient for promoting software reuse in a repository base integrated development environment, is to provide support for the software developer who wants to search the repository to locate and retrieve suitable software components for reuse. This paper presents that reusable software components form a base to provide a flexible representation of component adaptability to any repository with a specific classification. As an alternative, it proposes to automatically identify and convert the component source code with all its information into a standard form, so that components can be transferred from one type of library to another.

关键词： reusable software component classification representation adaptability transfer