检索结果-南通市图书馆

在线全文

学校读者我要写书评

暂无评论

地基不均匀沉降对框架结构影响的试验研究

土木工程学报 2011年第11期44卷 79-86页

作者：贾强程林林张鑫山东建筑大学山东济南250013 山东省建筑结构鉴定加固与改造重点实验室山东济南250013

地基不均匀沉降会引起框架结构产生附加内力,造成构件开裂甚至破坏。通过3跨框架结构的模型试验,研究框架结构在边柱沉降和中柱沉降两种工况下构件的开裂和破坏规律,提出地基不均匀沉降的限值。在边柱沉降的试验中,裂缝主要出现在边柱... 详细信息

地基不均匀沉降会引起框架结构产生附加内力,造成构件开裂甚至破坏。通过3跨框架结构的模型试验,研究框架结构在边柱沉降和中柱沉降两种工况下构件的开裂和破坏规律,提出地基不均匀沉降的限值。在边柱沉降的试验中,裂缝主要出现在边柱梁柱节点腋部、中柱梁柱节点顶部和中跨梁跨中顶部等部位,最终以边柱梁柱节点处裂缝贯通标志着构件的破坏。梁的转角正切达到1/250时,开始出现裂缝;梁的转角正切达到1/50时,构件达到承载力极限状态。中柱沉降的试验中,裂缝主要出现在边跨梁靠近边柱端上部、中跨梁跨中下部和中跨梁靠近节点端下部等,最终以中跨梁上部混凝土压酥标志着构件的破坏。梁的转角正切达到1/1250时,开始出现裂缝;梁的转角正切达到1/40时,构件达到承载力极限状态,试验结果与数值分析结果相吻合。

关键词：框架结构不均匀沉降试验研究附加内力

Negative differential resistance in molecular devices: the role of molecule-electrode coupling

在线全文

学校读者我要写书评

暂无评论

Science china(Physics,Mechanics & Astronomy) 2011年第8期Mechanics & Astronomy) .卷 1455-1460页

作者： ZHAI YaXin1, JI GuoMin1, FANG ChangFeng1, CUI Bin1, ZHAO Peng2 & LIU DeSheng1,3, 1 School of Physics, State Key Laboratory of Crystal Materials, shandong University, jinan 250100, china 2 School of Science, University of jinan, jinan 250022, china 3 Department of Physics and Information Engineering, Jining University, Qufu 273100, china 1. School of Physics State Key Laboratory of Crystal Materials Shandong University Jinan 250100 China2. School of Science University of Jinan Jinan 250022 China3. Department of Physics and Information Engineering Jining University Qufu 273100 China

By applying nonequilibrium Green's function formalism combined with the first-principles density functional theory, we investigate the electronic transport in two molecular junctions constituted by a substituted oligo (phenylene ehtynylene) sand-wiched between two Au electrodes. Our calculations show that the weak molecule-electrode coupling is responsible for the observation of the negative differential resistance (NDR) effect in experiments. When the coupling is weak, the projected density of states (PDOS) of the molecule and the electrodes undergoes a mismatch-match-mismatch procedure, which increases and then decreases the transmission peak intensities, leading to a NDR effect. We also find that the localization/delocalization of the molecular orbitals and the change of charge state of the molecule have no direct relation with the NDR effect, because they change little as the voltage increases.

关键词： negative differential resistance substituted oligo (phenylene ehtynylene) molecular junction density functional theory nonequilibrium Green’s function formalism

Laser　Diode－end－pumped　Laser　Performance　of　Nd－doped　Sr＿5（PO＿4）＿3F　at　1059　and　1328　nm

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Lasers 1996年第6期B5卷 497-500页

作者： SUN Lianke ZHANG Shaojun CHENG Ruping LIU Xunmin (Institute of Crystal Materials, shandong University, jinan 250100, china)ZHAO Shengzhi WANG Qingpu ZHANG Xingyu (Optics Department, shandong University, jinan 250100, china) shandong Univ Jinan China

ＬａｓｅｒＤｉｏｄｅ－ｅｎｄ－ｐｕｍｐｅｄＬａｓｅｒＰｅｒｆｏｒｍａｎｃｅｏｆＮｄ－ｄｏｐｅｄＳｒ＿５（ＰＯ＿４）＿３Ｆａｔ１０５９ａｎｄ１３２８ｎｍ￥ＳＵＮＬｉａｎｋｅ；ＺＨＡＮＧＳｈａｏｊｕｎ；ＣＨＥＮＧＲｕｐｉ... 详细信息

ＬａｓｅｒＤｉｏｄｅ－ｅｎｄ－ｐｕｍｐｅｄＬａｓｅｒＰｅｒｆｏｒｍａｎｃｅｏｆＮｄ－ｄｏｐｅｄＳｒ＿５（ＰＯ＿４）＿３Ｆａｔ１０５９ａｎｄ１３２８ｎｍ￥ＳＵＮＬｉａｎｋｅ；ＺＨＡＮＧＳｈａｏｊｕｎ；ＣＨＥＮＧＲｕｐｉｎｇ；ＬＩＵＸｕｎｍｉｎ（Ｉｎｓｔ...

关键词： PO Performance doped Diode Laser end pumped Nd nm Sr

Intermediate fertile Triticum aestivum (+) Agropyron elongatum somatic hybrids are generated by low doses of UV irradiation

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Cell Research 2004年第1期14卷 86-91页

作者： Ai Xia CHENG, Guang Min XIA~*, Da Ying ZHI, Hui Min CHEN School of Life Sciences, shandong University, jinan 250100, shandong, china. 1School of Life Sciences Shandong University Jinan 250100 Shandong China. 1School of Life Sciences Shandong University Jinan 250100 Shandong China. 1School of Life Sciences Shandong University Jinan 250100 Shandong China. 1School of Life Sciences Shandong University Jinan 250100 Shandong China.

We report the production and characterization of somatic hybrids between Triticum aestivum L. and Agropyron elongatum (Host) Nevishi (the synonym is Thinopyrum ponticum). Asymmetric protoplast fusion was performed between Agropyron elongatum protoplasts irradiated with a low UV dose and protoplasts of wheat taken from nonregenerable suspension cultures. More than 40 green plantlets were obtained from 15 regenerated clones and one of them produced seeds. The phenotypes of the hybrid plants and seeds were intermediate between wheat and Agropyron eIongatum. All of the regenerated calli and plants were verified as intergeneric hybrids on the basis of morphological observation and analysis of isozyme, cytological, 5SrDNA spacer sequences and random amplified polymorphic DNA (RAPD). RFLP analysis of the mitochondrial genome revealed evidence of random segregation and recombination of mtDNA.

关键词： Triticum aestivum Agropyron elongatum somatic hybridization mitochondrial genome.

Analysis about the Relationship between County Urbanization and Economy Growth in shandong Province

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Analysis about the Relationship between County Urbanization ...

Correlation of zeros of automorphic L-functions

2010 Third International Symposium on Knowledge Acquisition and Modeling (KAM 2010)

作者： Sun Ye Economic department shandong Jiaotong University jinan shandong Province china Yan Dezhi Economic department shandong Jiaotong University jinan shandong Province china

This article takes 31 county level cities in shandong Province as sample, carrying on empirical analysis about the relationship between county urbanization and economic growth through backward regression method. The result indicates the most important factor which promotes county economy growth is the development of secondary industry;the population urbanization factor has not entered regression equation, which indicates it is not significant to county economy growth;the coefficient of built-up district area factor is negative, which shows county urbanization in shandong province exists blind city area expansion and extensive growth. The result also indicates that county population urbanization is mainly driven by industrialization and resource consumption, while economy growth rate and built-up district area make less contribution to population urbanization.

关键词： County Urbanization Economic growth Backward regression.

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

Science china Mathematics 2008年第7期51卷 1147-1166页

作者： LIU JianYa1 & YE YangBo1,2 1 School of Mathematics,shandong University,jinan 250100, china 2Department of Mathematics,The University of Iowa,Iowa City,IA 52242-1419,USA 1. School of Mathematics Shandong University Jinan 250100 China 2. Department of Mathematics The University of Iowa Iowa City IA 52242-1419 USA

We compute the n-level correlation of normalized nontrivial zeros of a product of Lfunctions: L(s, π1) … L(s, π k ), where πj, j = 1, …, k, are automorphic cuspidal representations of GL mj (?A). Here the sizes of the groups GL mj (?A) are not necessarily the same. When these L(s, π j ) are distinct, we prove that their nontrivial zeros are uncorrelated, as predicted by random matrix theory and verified numerically. When L(s, π j ) are not necessarily distinct, our results will lead to a proof that the n-level correlation of normalized nontrivial zeros of the product L-function follows the superposition of Gaussian Unitary Ensemble (GUE) models of individual L-functions and products of lower rank GUEs. The results are unconditional when m 1, …, m k ? 4, but are under Hypothesis H in other cases.

关键词： automorphic L-function zero correlation Selberg’s orthogonality conjecture 11F70 11M26 11M41

Exact solutions for unsteady unidirectional flows of a generalized second-order fluid through a rectangular conduit

在线全文

学校读者我要写书评

暂无评论

Acta Mechanica Sinica 2009年第2期25卷 181-186页

作者： J. Kang M. Xu School of Mathematics, Institute of Applied Mathematics,shandong University, 250100 jinan, china M. Xu School of Mathematics Institute of Applied Mathematics Shandong University 250100 Jinan China

The exact solutions are obtained for unsteady unidirectional flows of a generalized second-order fluid through a rectangular conduit. The fractional calculus in the constitutive relationship of a non-Newtonian fluid is introduced. We construct the solutions by means of Fourier transform and the discrete Laplace transform of the sequential derivatives and the double finite Fourier transform. The solutions for Newtonian fluid between two infinite parallel plates appear as limiting cases of our solutions.

关键词： Generalized second-order fluid - Rectangularconduit Fractional calculus Exact solutions

A polynomial algorithm for finding (g,f)-colorings orthogonal to stars in bipartite graphs

在线全文

学校读者我要写书评

暂无评论

Science china Mathematics 2005年第3期48卷 322-332页

作者： LIU Guizhen & DENG Xiaotie Department of Mathematics, shandong University, jinan 250100, china Department of Computer Science, The City University of Hong Kong, Hong Kong, china 1. Department of Mathematics Shandong University 250100 Jinan China 2. Department of Computer Science The City University of Hong Kong Hong Kong China

Let G be a bipartite graph with vertex set V(G) and edge set E(G), and let g and f be two nonnegative integer-valued functions defined on V(G) such that g(x) ≤f(x)for every vertex x of V(G). A(g,f)-coloring of G is a generalized edge-coloring in which each color appears at each vertex x at least g(x) and at most f(x) times. In this paper a polynomial algorithm to find a(g, f)-coloring of a bipartite graph with some constraints using the minimum number of colors is given. Furthermore, we show that the results in this paper are best possible.

关键词： bipartite graph, (g, f)-coloring, (g, f)-factor, orthogonal coloring.

Structures of silylenoids and effects of metallic and haloid atoms on their stability

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Chemistry 1995年第1期13卷 19-26页

作者： FENG, Sheng-Yu FENG, Da-Cheng DENG, Cong-HaoTheoretical Chemistry Group, shandong University, jinan, shandong 250100, china Theoretical Chemistry Group Shandong University Jinan Shandong 250100 China

The structural characteristics of silylenoids, H2SiMX, where M = Li or Na and X = F or Cl, have been studied by ab initio calculations. H2SiMX can be represented as adducts of silylene H2Si with alkali metal halogenides, MX. The associative energies at different calculational levels of various structures of H2SiMX are given. Effects of metallic and haloid atoms on the stability of various structures of H2SiMX are also discussed in this paper.

关键词： Silylenoid three-membered ring structure p-complex structure associative energy structural stability.