检索结果-南通市图书馆

ON THE CONVERGENCE OF ASYNCHRONOUS NESTEDMATRIX MULTISPLITTING METHODS FOR LINEARSYSTEMS

在线全文

学校读者我要写书评

暂无评论

Journal of Computational Mathematics 1999年第6期17卷 575-588页

作者： bai, zz Wang, DR Evans, DJ Acad Sinica State Key Lab Sci Engn Comp Inst Computat Math & Sci Engn Comp Beijing 100080 Peoples R China Shanghai Univ Dept Math Shanghai 201800 Peoples R China Loughborough Univ Technol Parallel Algorithms Res Ctr Loughborough LE11 3TU Leics England

A class of asynchronous nested matrix multisplitting methods for solving large-scale systems of linear equations are proposed, and their convergence characterizations are studied in detail when the coefficient matrice... 详细信息

关键词： solution of linear systems asynchronous parallel iteration matrix multisplitting relaxation method convergence

A CLASS OF ASYNCHRONOUS MATRIX MULTI-SPLITTING MULTI-PARAMETER RELAXATION ITERATIONS

在线全文

学校读者我要写书评

暂无评论

Journal of Computational Mathematics 1998年第3期16卷 221-238页

作者： bai, zz Wang, DR Evans, DJ Chinese Acad Sci ICMSEC Beijing 100080 Peoples R China Shanghai Univ Dept Math Shanghai 201800 Peoples R China Loughborough Univ Technol Dept Comp Studies Loughborough LE11 3TU Leics England

A class of asynchronous matrix multi-splitting multi-parameter relaxation methods, including the asynchronous matrix multisplitting SAOR, SSOR and SGS methods as well. as the known asynchronous matrix multisplitting AOR, SOR and GS methods, etc., is proposed for solving the large sparse systems of linear equations by making use of the principle of sufficiently using the delayed information. These new methods can greatly execute the parallel computational efficiency of the MIMD-systems, and are shown to be convergent when the coefficient matrices are H-matrices. Moreover, necessary and sufficient conditions ensuring the convergence of these methods are concluded for the case that the coefficient matrices are L-matrices.

关键词： system of linear equations asynchronous iteration matrix multisplitting relaxation convergence

Self-consistent Constitutive Modeling of the Creep Damage Behaviour of Nickel-base Directionally Solidified Superalloys with Different Grain Orientations

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 1998年第1期14卷 15-19页

作者： Yue, ZF Lu, zz Northwestern Polytech Univ Dept Appl Mech Xian 710072 Peoples R China

A self-consistent creep damage constitutive model is developed for nickel-base directionally solidified superalloys. Grain degradation and grain boundary voiding are considered. The model parameters are determined from the creep test data of single crystal and directionally, solidified superalloy with a special grain orientation. The numerical analysis shows that the model creep damage behaviours of nickel-base directionally solidified superalloys with different grain orientations are in good agreement with the experimental data.

关键词： Nickel alloys

The Electronic Structures of Dimeric Diboroxane and Aldiminoborane

在线全文

学校读者我要写书评

暂无评论

Chemical Research in Chinese Universities 1995年第3期11卷 232-237页

作者： WANG, zz XU, M YANG, zz JILIN UNIV INST THEORET CHEMCHANGCHUN 130023PEOPLES R CHINA JILIN UNIV NATL LAB THEORET & COMPUTAT CHEMCHANGCHUN 130023PEOPLES R CHINA

e have studied the electronic structures of dimeric diboroxane and aldiminob-orane by nieans of STO-3G .ib iuitio SCF method. The energies and the componentanalysis of niolecular orbitals near to frontier orbital have been given. By bothKoopman' s theoreni and △E_(scf)mietliod we have calculated the ionization potentialsof 8 higlier occupied orbitals and discussed the electron relaxation effect on IP' s cal-culations and the charge distribuuons for the two molecules.

关键词： Diboroxane Aldiniuioborane ab initio SCF method

Grain Boundary-induced Shielding of Ni-base Single Crystals: Experimental and Analytical Study

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 1999年第5期15卷 463-468页

作者： Yue, ZF Lu, zz Wu, DQ Northwestern Polytech Univ Dept Engn Mech Xian 710072 Peoples R China

Fracture behavior was studied for Ni-base single crystals and Ni-base bicrystals. The single crystals were machined from the bicrystal specimens to ensure that the single crystal samples had the same properties as those of the grains in the bicrystals. Using the three-point bend specimens, the fracture toughness K-c of single crystals acid grain boundaries was measured, respectively. The two toughness values were little dependent on the ratio of the crack length to the height of the specimens. The grain boundary-induced shielding effect of fracture toughness was found in the grain-cracked bicrystals with normal front grain boundaries. The toughness varied with the distance between the crack tip and grain boundary. With the help of SEM analyses and numerical calculations, the mechanisms for the grain boundary-induced shielding are revealed. It is the grain boundary-induced redistribution of stresses and strains near the crack tip that induces the grain boundary-induced shielding. And the strain energy density criterion can be applied to the fracture of bicrystals. Agreement with experiments is good.

关键词： Nickel alloys

Separation of Cobalt from Iron by Chloride Hydrolysis at Elevated Temperature

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 1997年第5期13卷 421-424页

作者： Ma, KY Zhu, zz Yan, CY Kunming University of Science and Technology Kunming 650093 China

The hydrolysis rate of Go-bearing ferrous chloride at elevated temperature and the conditions of separation of Co from Fe have been investigated. The hydrolysis process is comprised of the interfacial chemical reaction and the intra-grain diffusion. At the stage under the control of the interfacial chemical reaction, the apparent rate constant k equals to 198.79exp(-80.57/RT). The effects of the temperature, the partial pressure ratio of water vapor and the reaction time on the Co recovery and the separation of Co from Fe are examined. The optimum hydrolysis conditions are determined.

关键词： Cobalt metallurgy

Human hepatopoietin and its relationship with liver regeneration

在线全文

学校读者我要写书评

暂无评论

Chinese Science Bulletin 1997年第18期42卷 1505-1511页

作者： He, FC Wu, zz Institute of Radiation Medicine Beijing China

IT is *** to see the regeneration of affiliated organs or limbs in the lower living beings. However, the regeneration ability in higher mammals is extremely limited. Therefore,the regeneration ability possessed peculiarly by mammal liver attracts great attention. That solely high regeneration ability has been discovered for thousands of years and yet the studies on the mechanism were initiated only a hundred years ago. The key breakthrough happened in 1931 when Higgins and Anderson established the hepatic regeneration model by partial hepatectomy in rats. Since then, the successive studies on liver regeneration mechanism have been focused on analysis and identification of the events initiating the regenerative process.

关键词： human hepatopoietin liver regeneration severe hepatic diseases molecular cloning rccombinant product.

The characteristics and recognition of internal-tide and internal-wave deposits

在线全文

学校读者我要写书评

暂无评论

Chinese Science Bulletin 1999年第7期44卷 582-589页

作者： He, YB Gao, zz Jianghan Petr Inst Dept Geol Jingzhou 434102 Peoples R China

Internal-tide and internal-wave deposits are a new and important type of deep-water traction-current deposits. Based on an analysis of documented internal-tide and internal-wave deposits, five facies types can be recognized: ( ⅰ ) bidirectional cross-laminated sandstone facies, ( ⅱ ) unidirectional cross-bedded and cross-laminated sandstone facies, ( ⅲ ) rhythmic alternating sandstone facies and mudstone, ( Ⅳ ) flaser, wavy and lenticular bedded foraminiferal limestone facies, ( Ⅴ ) sandy oolitic limestone facies with flaser, wavy and lenticular bedding and epsilon cross bedding, which formed in submarine channel, unchannelized continental slope and plateau environments respectively. Accoding to the available data and knowledge,three sedimentation models are built; some discriminating characteristics of internal-tide and internal-wave deposits, and the distinction between them and contourites and turbidites are summed up.

关键词： internal tide internal-tide deposit sedimentary facies sedimentation model discriminating characteristics.

THE FULLY PLASTIC J-INTEGRAL OF CORNER CRACKS AT A HOLE IN A PLATE

在线全文

学校读者我要写书评

暂无评论

Acta Mechanica Solida Sinica 1997年第2期10卷 131-137页

作者： Gao, Q Huang, zz SW JIATONG UNIV INST APPL MECHCHENGDU 610031PEOPLES R CHINA

The line-spring model of surface cracks is applied to the fully plastic analysis of corner cracks at a hole in a plate. The generalized fully plastic constitutive relations and the fully plastic J-integral, as well as its coefficients in polynomial expressions are given. The model obtained is incorporated into a finite element program. The corner cracks at a hole in a plate subjected pure tensions are calculated by the present model. The fully plastic J-integral is then estimated. The results obtained show that the line-spring model is effective for the analysis of corner cracks. The influence of the crack depth and the hardening exponent on the fully plastic J-integral is also discussed.

关键词： corner crack line-spring model fully plastic J-integral