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Relationship among Parameters Evaluating Stress Corrosion Cracking

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Journal of Materials Science & Technology 2000年第5期16卷 504-508页

作者： Wuyang CHU+, Lijie QIAO and Yanbin WANG (department of Materials physics, {2. of Science and Technology beijing, beijing 100083, china) department of Materials physics University of Science and Technology Beijing Beijing 100083 China

The threshold stress, σc, for sulfide stress corrosion cracking (SCC) of seven pipeline steels and five other steels, the critical stress, Sc, for seven pipeline steels and two drill rod steels with various strengths and the susceptibility to SCC, IRA or σf(SCC)/σf, for four pipeline steels, two drill rod steels and five other steels were measured. The results showed that there are no definite relationships among σc, Sc and IRA or σf(SCC)/σ*** threshold stress for hydrogen induced cracking (HlC) during charging with loading in the H2.04 solution, σc(H), decreased linearly with logarithm of the concentration of diffusible hydrogen c0, i.e., σc(H)=A-B Inco for four pipeline steels. σc(H) obtained with a special cathodic current ic, which was corresponding to the diffusible hydrogen concentration during immersing in the H2. solution, were consistent with /c for sulfide SCC for four pipeline steels. Therefore, σc for sulfide SCC can be measured using dynamically charging in the H2.O4 solution with the special cathodic current ic.

关键词： SCC Relationship among Parameters Evaluating Stress Corrosion Cracking HIC

Applications of URANS on predicting unsteady turbulent separated flows

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Acta Mechanica Sinica 2009年第3期25卷 319-324页

作者： Jinglei Xu Huiyang Ma department of physics, Graduate {2. of the Chinese Academy of Sciences, 100049 beijing, china department of physics Graduate University of the Chinese Academy of Sciences 100049 Beijing China

Accurate prediction of unsteady separated turbulent flows remains one of the toughest tasks and a practi cal challenge for turbulence modeling. In this paper, a 2. flow past a circular cylinder at Reynolds number 3,900 is numerically investigated by using the technique of unsteady RANS （URANS）. Some typical linear and nonlinear eddy viscosity turbulence models （LEVM and NLEVM） and a quadratic explicit algebraic stress model （EASM） are evaluated. Numerical results have shown that a high-performance cubic NLEVM, such as CLS, are superior to the others in simulating turbulent separated flows with unsteady vortex shedding.

关键词： URANS Nonlinear eddy viscosity turbulencemodel ,Separated flows Circular cylinder

Near generalized balanced tournament designs with block sizes 4 and 5

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Science china Mathematics 2009年第9期52卷 1927-1938页

作者： SHAN XiuLing1, 2.1 department of Mathematics, beijing Jiaotong {2., beijing 100044, china 2.College of Mathematics and Information Science, Hebei normal {2., Shijiazhuang 050016, china department of Mathematics Beijing Jiaotong University Beijing 100044 China College of Mathematics and Information Science Hebei Normal University Shijiazhuang 050016 China

A near generalized balanced tournament design, or an NGBTD(k,m) in short, is a (km+1,k,k-1)-BIBD defined on a (km+1)-set V . Its blocks can be arranged into an m×(km+1) array in such a way that (1) the blocks in every column of the array form a partial parallel class partitioning V\{x} for some point x, and (2. every element of V is contained in precise k cells of each row. In this paper, we completely solve the existence of NGBTD(4,m) and almost completely solve the existence of NGBTD(5,m) with four exceptions.

关键词： near generalized balanced tournament designs frame generalized doubly resolvable packing constructions existence 05B05

Pairing problem of generators in Kac-Moody algebras

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Chinese Science Bulletin 1998年第22期43卷 1872-1879页

作者： LU Caihui department of Mathematics, Capital normal {2., beijing 100037, china department of Mathematics Capital Normal University Beijing China

The following result is proved: in any Kac Moody algebra g(A) , (ⅰ) given any non central element h in the Cartan subalgebra  , or (ⅱ) given any real root vector x β, β∈Δ re . There exists y∈g(A) such that th... 详细信息

关键词： generator root system real root vector.

Extremal problems on the Hua domain of the first type

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Science china Mathematics 2005年第z1期48卷 343-354页

作者： SU Jianbing & YIN Weiping Mathematics department, Xuzhou normal {2., Xuzhou 2.1116, china Mathematics department, Capital normal {2., beijing 100037, china 1. Mathematics department Xuzhou Normal University 221116 Xuzhou China 2. Mathematics department Capital Normal University 100037 Beijing China

In this paper we study some extremal problems between the Hua domain of the first type and the unit ball.

关键词： extremal problem, Hua domain of the first type, minimal circumscribed Hermitian ellipsoid.

Extremal problems on the generalized Hua domain of the first type

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Progress in Natural Science:Materials International 2006年第4期16卷 352-358页

作者： SU Jianbing and YIN Weiping department of Mathematics, Xuzhou normal {2., Xuzhou 2.1116, china department of Mathematics, Capital normal {2., beijing 100037, china [a]department of Mathematics Xuzhou Normal University Xuzhou China [b]department of Mathematics Capital Normal University Beijing China

Some extremal problems between the generalized Hua domain of the first type and the unit ball are studied. The extremal mapping and extremal value in explicit formulas are also obtained.

关键词： extremal problem generalized Hua domain of the first type minimal circumscribed Hermitian ellipsoid.

Differential operators and automorphism schemes

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Science china Mathematics 2010年第9期53卷 2363-2380页

作者： LI KeZheng department of Mathematics,Capital normal {2.,beijing 100048,china 1. department of Mathematics Capital Normal University Beijing 100048 China

The ring of global differential operators of a variety is in closed and deep relation with its automorphism *** relation can be applied to the study of homogeneous schemes,giving some criteria of homogeneity,a general... 详细信息

关键词： differential operator deformative automorphism automorphism scheme homogeneous scheme abelian variety

Solving the input data in error correc-tion of optical fabrication by finite Fourier coefficient algorithm

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Science china(Technological Sciences) 2006年第1期49卷 50-60页

作者： CHENG Haobo1,2. SUN Guozheng3 & FENG Zhijing2.1. department of Optical Engineering, beijing Institute of Technology, beijing 100081, china 2. department of Precision Instruments and Mechanology, Tsinghua university, beijing 100084, china 3. china North Industries Group Corporation, beijing 100089, china 1. department of Optical Engineering Beijing Institute of Technology Beijing 100081 China 2. department of Precision Instruments and Mechanology Tsinghua University Beijing 100084 China 3. china North Industries Group Corporation Beijing 100089 China

A free-form lens (FFL) is a special surface that is difficult to be fabricated. FFL are usually fabricated by computer-controlled optical surfacing (CCOS) technique. During CCOS, the material removal amount is determined by the unit removal function (URF) convoluting with the input data――the dwell time. When the removal amount and the URF are known, how to solve the input data involves the special algorithm――deconvolution. Usually, the input data are solved by virtue of low pass filter or iterative methods. However, an approximation solution would destroy the machining stability nec-essary to perform precisely CCOS. In this paper, to solve the input data, a new method that is based on the finite Fourier coefficient is put forward. It can give a continuous and accurate solution for fabricating choice. Several parameters are simulated, which influ-ence the process of CCOS, and evaluating on the effect of the method is also carried out. Experimental results verify that this method is suitable for guiding the manufacturing of high precision FFL.

关键词： optical fabrication, computer controlled optical surfacing, free-form lens, finite Fourier coefficient, error correction.

Complete multiple round quantum dense coding with quantum logical network

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Chinese Science Bulletin 2007年第9期52卷 1162-1165页

作者： LI ChunYan1,2.LI XiHan1,2.DENG FuGuo1,2.3,ZHOU Ping1,2.& ZHOU HongYu1,2.3 1 Key Laboratory of Beam Technology and Material Modification of Ministry of Education,beijing normal {2.,beijing 1.0875,china 2.Institute of Low Energy Nuclear physics,and department of Material Science and Engineering,beijing normal {2.,beijing 1.0875,china 3 beijing Radiation Center,beijing 1.0875,china Key Laboratory of Beam Technology and Material Modification of Ministry ofEducation Beijing Normal University Beijing 100875 China

We present a complete multiple round quantum dense coding scheme for improving the source ca-pacity of that introduced recently by Zhang et al. The receiver resorts to two qubits for storing the four local unitary ope... 详细信息

关键词：量子通信多重量子紧凑编码量子逻辑网络量子纠缠