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ANALYSING THE EFFICIENCY OF SOLVING DENSE LINEAR EQUATIONS ON DWNING1000

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Journal of Computational Mathematics 1996年第4期14卷 383-386页

作者： X.B. Chi(institute of Software, chinese academy of sciences, beijing, china) 中科院软件所北京

In this paper, we consider solving dense linear equations on Dawning1000 byusing matrix partitioning technique. Based on this partitioning of matrix, we give aparallel block LU decomposition method. The efficiency of solving linear equationsby different ways is analysed. The numerical results are given on *** running our parallel program, the best speed up on 32 processors is over 25.

关键词： ANALYSING THE EFFICIENCY OF SOLVING DENSE LINEAR EQUATIONS ON DWNING1000

Tree　ring　analysis　for　determination　of　pollution　history　of　Chengde　City，north　china

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Journal of Environmental sciences 1996年第1期8卷 77-85页

作者： Jiang Gaoming(institute of Botany, chinese academy of sciences,beijing 100044,china ) Inst Botany Chinese Acad of Sci Beijing China China

Air pollution history of sulphur and heavy metals since 1800 in Chengde City , north china,was studied by analyzing the concentrations of sulphur and heavy metals in growth rings of Pinus tabulaeformis Carr. Sulphur concentrations in the tree rings of 1910-1920, 1970-1980,and 1980-1990 have increased 1-2 , 3-5 and 10 times respectively as those in the tree ring of 1810-1820 (P china was founded.

关键词： tree rings Pinus tabulaeformis sulphur and heavy metals pollution history Chengde

Study on Dynamical Behavior of Turbulent Premixed V-flames

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Journal of Thermal Science 2003年第4期12卷 381-384页

作者： Baorui Wang Kun Yuan Xiaoqian Zhanginstitute of Engineering Thermophysics, chinese academy of sciences, beijing 100080, china institute of Engineering Thermophysics Chinese Academy of Sciences Beijing China

Differential interference contrast method was applied to investigate the flickering characteristics of V-flame in terms of both temporal and spatial scales. The flow characteristics of incident premixed combustibles were measured by means of laser Doppler anemometry (LDA). The characteristics of wake flow behind the stabilizing rod were obtained with numerical simulation. While the integral temporal scale of incident turbulence is about 1ms, the integral spatial scale about 2 mm, the characteristic flickering time scale is about 83 ms and spatial scale about 10 mm. The flame flickering frequency is more than 12 Hz, does not comply with the wake vortex shedding frequency, which is about 110 Hz. It is well-known that the flickering of V-flame is affected by both the incident turbulence and the wake flow after the stabilizing rod, but the result of the paper shows that the relationship between flickering characteristics and flow characteristics is much more complicated by the chemical reaction.

关键词： premixed flame turbulence numerical simulation.

Enthalpy and entropy interaction parameters of sodium chloride with some monosaccharides in water

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Science china Chemistry 2004年第1期47卷 59-66页

作者： ZHUO Kelei, WANG Jianji, BAI Guangyue, YAN Haike & WANG HangingSchool of Chemistry and Environmental Science, Henan Normal University, Xinxiang 453002, china institute of Chemistry, chinese academy of sciences, beijing 100080, china Lanzhou institute of Chemical physics, chinese academy of sciences, Lanzhou 730000, china 1. School of Chemistry and Environmental Science Henan Normal University 453002 Xinxiang China 2. institute of Chemistry Chinese Academy of Sciences 100080 Beijing China 3. Lanzhou institute of Chemical physics Chinese Academy of Sciences 730000 Lanzhou China

Dilution enthalpies of sodium chloride and some monosaccharides (glucose, galactose, xylose, arabinose, and fructose) in water and mixing enthalpies of aqueous sodium chloride and these monosaccharide solutions were measured by using an improved precision semimicro-titration calorimeter. Transfer enthalpies of sodium chloride from water to aqueous saccharide solutions were evaluated as well as enthalpy interaction parameters of sodium chloride with these monosaccharides in water. Combined with Gibbs energy interaction parameters, entropy interaction parameters were also obtained. The results show that interactions of the saccharides with sodium chloride depend on the stereochemistry of saccharide molecules. These interaction parameters can identify stereochemical structure of saccharide molecules. Keywords sodium chloride - monosaccharide - enthalpy interaction parameter - entropy interaction parameter - calorimetry

关键词： sodium chloride, monosaccharide, enthalpy interaction parameter, entropy interaction parameter, calorimetry.

The Multifractal Analysis of the Occupation Measure of a Lévy Process

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Wuhan University Journal of Natural sciences 2000年第3期5卷 253-256页

作者： Hu Xiao\|yu institute of Applied Mathematics, chinese academy of sciences, beijing 100080, china chinese academy of sciences Institute of Applied Mathematics Beijing China (GRID:grid.9227.e) (ISNI:***)

We introduce the results on the multifractal structure of the occupation measures of a Brownian Motion, a stable process, a general subordinator and a stochastic process derived from random reordering of the Cantor se... 详细信息

关键词： occupation measure Levy process Brownian motion stable process subordinator

Structural and microstructural transformations in Bi_2Sr_2Ca_(1-x)Y_xCu_2O_(8+y) system

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chinese Science Bulletin 1997年第3期42卷 192-196页

作者： SONG Chengyu, WEN Shulin and CHE Guangcan1. Shanghai institute of Ceramics, chinese academy of sciences, Shanghai 200050, china 2. State Key Laboratory of Supercon-ductivity, institute of physics, chinese academy of sciences, beijing 100080, china Shanghai institute of Ceramics Chinese Academy of Sciences Shanghai 200050 China

SINCE the discovery of high-Tc superconductors, experiments have revealed that the phase diagrams of La2-xSrxCuO4 and YBa2Cu3O6+x resemble each other. The antiferromagnetic phase is commonly situated in the vicinity o... 详细信息

关键词： Bi2Sr2Ca1-xYxCu2Oy substitution structural transformation.

A simple proof of the formal duality of the Kerdock and Preparata codes

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chinese Science Bulletin 2000年第14期45卷 1279-1282页

作者： WAN Zhexianinstitute of Systems Science, chinese academy of sciences, beijing 100080, china institute of Systems Science Chinese Academy of Sciences Beijing China

The nonlinearity of the Z2-Kerdock code Km+1, where m is an odd integer ≥3, is not at all obvious. By regarding Km+1 as the binary image of the Z4-Kerdock code .,K(m) under the Gray map[1], a simple proof can be achieved (cf. Theorems 8.7 and 8.9 of [2]). Similarly, the formal duality of the Z2-Kerdock code Km+1 and the Z2-Preparata code Pm+1 is even more not at all obvious. A simple proof is given in the present note, by regarding Km+1 as the binary image of .K (m) and using the duality of .K(m) and the Z4-Preparata code . (m) established in [1].

关键词： 4-code. Kerdock code Preparata code formal duality.

RECOVERY OF AMORPHOUS POLY(ETHYLENE TEREPHTHALATE)FILM UNIAXIALLY DRAWN JUST BELOW THE GLASS TRANSITION TEMPERATURE

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chinese Journal of Polymer Science 2000年第1期18卷 69-75页

作者： Nan-jian Sun Juan Yang De-yan Shen Ren-yuan Qian institute of Chemistry, chinese academy of sciences, beijing 100080, china chinese Acad Sci Inst Chem Beijing 100080 Peoples R China

Isothermal recovery in the macroscopic length of homogeneously deformed specimens of amorphous poly(ethylene terephthalate) (PET) film sample uniaxially drawn at 69 degrees C to the draw ratios lambda(0) = 1.26-2.20 were studied at temperatures around the glass transition temperature (T-g = 73 degrees C). Experimental results indicate that the length recovery look place in two distinct steps: a fast first step (fast relaxation) followed by a slow second step (slow relaxation). The relaxation processes were accompanied by the reversion of trans-conformers (1340 cm(-1)) to gauche, and the dichroic function of the 1340 cm(-1) band characterizing the segmental orientation along the chain direction decreased to a very low value at the end of the fast relaxation. This fact led us to assign the fast relaxation as the segmental orientation while the slow relaxation as relaxation of the global chain orientation. It was found that the slow relaxation follows a single exponential function, with relaxation times strongly dependent on the temperature resembling the glass transition process. The fast relaxation does not follow a single exponential decay, presumably a distribution of relaxation times is involved.

关键词： poly(ethylene terephthalate) uniaxial drawing recovery orientation

Existence of SURU estimators in SURE model with special covariance structures

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chinese Science Bulletin 1997年第14期42卷 1149-1151页

作者： WU Qiguanginstitute of Systems Science, chinese academy of sciences, beijing 100080, china institute of Systems Science Chinese Academy of Sciences Beijing China

THROUGHOUT this note, the following notations are used: For a matrix A, A>0 means thatA is positive definite symmetric; R （A）, A′and A- stand for the column space, transposeand any g-inverse of A respectively; PA = A （A′A）- A′and PA = Ik - PA, where Ik is theidentity matrix of order k that is the number of rows in A. Rm×n is the totality of m×n realmatrices.

关键词： seemingly unrelated regression equations (SURE) model uniformly minimum risk unbiased (UMRU) estimator uniform covariance structure serial covariance structure.