检索结果-南通市图书馆

TEXTURE DETERMINATION OF THIN FILM ZrO_2 BY ELECTRON DIFFRACTION

在线全文

学校读者我要写书评

暂无评论

Acta Metallurgica Sinica(English Letters) 1993年第12期6卷 472-473页

作者： WANG Yinghua Tsinghua university,Beijing,China Department of Materials Science and Engineering,Tsinghua university,Beijing 100084,China Tsinghua Univ Beijing China

A method for semi-quantitative determination of thin film texture using electron diffrac- tion is *** texture state of a zirconia thin film with a cubic structure has been determined in this way and is presented as an... 详细信息

关键词： texture thin film electron diffraction ZrO_2

STUDY ON THE TEN MAJOR TREE SPECIES OCCUPYING GEOGRAPHICAL SPACE IN NATURAL SECONDARY FOREST USING SPACE ANALYSIS

在线全文

学校读者我要写书评

暂无评论

Journal of Northeast Forestry university 1993年第2期4卷 51-56页

作者： Li RuxiuNortheast Forestry university Northeast Forestry university China

The paper studies ten major tree species occupying the space in naturalsecondary forests in Mao Er mountain *** space is divided into horizon,elevation,slope,aspect and topographic position *** features of the species of trees areexamined using the concept of distribution width and the method of space *** of analysis indicate that Aspen and Asian White Birch community of forests inthe area would become failing,and the distribution of Mongolian Oak and Mongolian Lidenand Manchurian Walnut are Limited by the slope and aspect and topographic ***,Maple,Manchurian Ash would become the major species constituting naturalsecondary forests in future in this area.

关键词： Species of tree Geographic space Distribution Space analysis

PARAMETERS OF DARBOUX TRANSFORMATION FOR REDUCED AKNS,KAUP-NEWELL AND PCF SYSTEMS

在线全文

学校读者我要写书评

暂无评论

Chinese Annals of Mathematics,Series B 1999年第2期20卷 195-204页

作者： ZHOU ZIXIANG(Institute of Mathematics, Fudan university, Shanghai 200433) Institute of Mathematics Fudan University Shanghai 200433 China

FOr the integrable system with u(p, q) reduction, there is a well-known sufficient conditionto choose the parameters: the spectral parameters only take two mutually conjugate valuesand the solutions of the Lax pair should satisfy certain orthogonal relations. In this paper, theauthor proves that, for the AKNS system, the Kaup-Newed system and the principal chiralfield (PCF), this condition is also necessary for generic potentials with the u(p, q) *** some other reductions, sufficiency and necessity of more constraints are proved.

关键词： Darboux transformation Spectral parameters u(p q) reduction

NEW VISUAL METHOD FOR FREE-FORM SURFACE RECONSTRUCTION

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Mechanical Engineering 2002年第1期15卷 35-39页

作者： Xiong Hanwei Artificial Intelligence Institute，Zhejiang university，Hangzhou 310027，China Zhang Xiangwei Guangdong university of Technology Artificial Intelligence Institute Zhejiang University Hangzhou 310027 Guangdong university of Technology

A new method is put forward combining computer vision with computer aidedgeometric design (CAGD) to resolve the problem of free-form surface reconstruction. The surface isfirst subdivided into N-sided Gregory patches, and a stereo algorithm is used to reconstruct theboundary curves. Then, the cross boundary tangent vectors are computed through reflectance *** last, the whole surface can be reconstructed jointing these patches with G^1 continuity(tangentcontinuity). Examples on synthetic images are given.

关键词： Reverse engineering Free-form surface design Computer vision

L-R smash products for bimodule algebras

在线全文

学校读者我要写书评

暂无评论

Progress in Natural Science:Materials International 2006年第6期16卷 580-587页

作者： ZHANG Liangyun (Department of Mathematics, Nanjing Agricultural university, Nanjing 210095, China Department of Mathematics, Nanjing university, Nanjing 210008, China) Department of Mathematics Nanjing Agricultural University Nanjing 210095 China Department of Mathematics Nanjing U-niversity Nanjing 210008 China

In this paper, we prove that the L-R smash product A(?)H is exactly the twisted smash product A * H if H is a finite dimensional cocommutative Hopf algebra, and give a sufficient and necessary condition for L-R smash products to be bialgebras (Hopf algebras) . For any finite dimensional coquasitriangular Hopf algebra (H,σ), we prove that the L-R smash product H(?)H is semisimple Artinian if H is semisimple and H * is unimodular. In particular, the L-R smash product D(H)* (?)D(H)* semisimple Artinian if the Drin-fel'd double D(H) is semisimple.

关键词： bimodule algebras L-R smash products coquasitriangular Hopf algebras Long bialgebras.

DIRECT SPECTURM ANALYSIS OF THE STATE SPACE FOR RANDOM VIBRATION OF MDOF LINEAR DAMPED SYSTEM

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Acta Mechanica Sinica 1990年第4期6卷 367-373页

作者： Zheng Zhaochang (Tsinghua university) Tsinghua university Beijing China

This paper proceeds from the general case of the unsymmetric linearized multi-degrees of free- dom(MDOF)*** adopting the general complex modal theory of the state space,the response analysis for a sys- tem subjected to random excitation of the same source is carried out using as a kind of direct spectrum analysis method in frequency *** the input of power spectral density function given,the explicit expression of the power spectral density function matrix of the output response can be *** taking Fourier inverse transform,the integrated expres- sions of the correlation function matrix and of the spectrum moment matrix are *** with the time domain method,this method enjoys the merit of visualization and avoids the procedure of transformation from the obtained re- sponse correlation function to be solved for the output spectrum utilizing Fourier *** paper has extended the application range of the traditional frequency domain analysis *** mean square values and variety of statistical val- ues can be obtained *** method and the time domain method are different in approach but equally satisfac- tory in their results.

关键词： spectrum analysis space state complex modal random vibration

Maschke-type theorem and Morita context over weak Hopf algebras

在线全文

学校读者我要写书评

暂无评论

Science China Mathematics 2006年第5期49卷 587-598页

作者： ZHANG Liangyun College of Science, Nanjing Agricultural university, Nanjing 210095, China Department of Mathematics, Nanjing university, Nanjing 210008, China College of Science Nanjing Agricultural University Nanjing China Department of Mathematics Nanjing University Nanjing China

This paper gives a Maschke-type theorem over semisimple weak Hopf algebras,extends the well-known Maschke-type theorem given by Cohen and Fishman and constructs a Morita context over weak Hopf algebras.

关键词： weak Hopf algebra, smash product, Maschke-type theorem, Morita context.

INFLUENCE OF FIRE ON KOREAN PINE AND SCOTS PINE TREES IN PLANTATION

在线全文

学校读者我要写书评

暂无评论

Journal of Northeast Forestry university 1993年第2期4卷 11-17页

作者： Liu HuirongNortheast Forestry university Northeast Forestry university China

The plantations of korean pine (Pinus koraensis) and scots pine (Pinus sylvesris var. mongolica) are mainly pure stands. Fires are gradually causing problems in these plantations and being paid much more attention recently. Study on the influence of fire on trees and the adaptation to fire, therefore, is of great important to probe the fire ecological properties and the protection ways of these two species. The results are as follows: Both of the species are easily damaged by fire, but korean pine is more susceptible. In the same fire, korean pine is damaged more seriously than scots pine although they have the same size. Young individuals have low fire resistant capacity and can be damaged seriously, and older ones have strong fire resistance and can be damaged lightly. Up-hill fire makes a serious damage to the trees distributed in up-slopes with the reason of higher fire intensity. Down -hill fire makes a serious damage to the trees distributed in down-slopes with the reason of higher fire severity. The larger deocambium area in the tree bark is, the earlier tree growth after fire is. During the early growth stage, the damaged tree bark will Spill over much resin. The height of running resin is higher than that of dead cambium. Damaged trees sprout and grow more slowly and the length of leaves are shorter than these normal trees. The chiorophyll content of serious damaged trees is much higher than that of normal trees. The chiorophyll content of dying trees is 64. 29% higher than that of the contrast ones. Cell membrance penetrability of damaged trees is also higher than that of normal trees.

关键词： Fire Korean pine Mongolian scots pine Chlorophyll

L~∞ CONVERGENCE OF TRUNC ELEMENT FOR THE BIHARMONIC EQUATION

在线全文

学校读者我要写书评

暂无评论

Journal of Computational Mathematics 1997年第1期15卷 14-22页

作者： M. Wang(Department of Mathematics, Beijing university, Beijing, China) 北京大学数学系北京

The paper considers the L∞ convergence for TRUNC finite elements solving the boundary value problems of the biharmonic equation. The nearly optimal L∞ estimates for the error of first order derivatives are *** TRUNC plate element is proposed and developed by Argyris et al.. The numerical experiences show that the element has very good .***,[1l2]. The mathematicalproof of convergence of the TRUNC element is given by Shi Zong-ci in paper [3]. Thispaper will consider the L~∞ convergence for the TRUNC plate element.

关键词：双谐波方程边值问题收敛性有限元法