首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   1588篇
  免费   53篇
  国内免费   6篇
化学   1258篇
晶体学   13篇
力学   11篇
数学   74篇
物理学   291篇
  2023年   10篇
  2022年   12篇
  2021年   16篇
  2020年   16篇
  2019年   26篇
  2018年   18篇
  2017年   22篇
  2016年   31篇
  2015年   33篇
  2014年   37篇
  2013年   90篇
  2012年   79篇
  2011年   113篇
  2010年   48篇
  2009年   48篇
  2008年   109篇
  2007年   94篇
  2006年   84篇
  2005年   86篇
  2004年   89篇
  2003年   81篇
  2002年   86篇
  2001年   28篇
  2000年   30篇
  1999年   22篇
  1998年   19篇
  1997年   14篇
  1996年   20篇
  1995年   12篇
  1994年   9篇
  1993年   12篇
  1992年   6篇
  1991年   12篇
  1990年   19篇
  1989年   14篇
  1988年   12篇
  1987年   7篇
  1986年   9篇
  1985年   16篇
  1984年   21篇
  1983年   6篇
  1982年   12篇
  1981年   17篇
  1980年   14篇
  1979年   8篇
  1978年   8篇
  1977年   16篇
  1976年   8篇
  1975年   8篇
  1967年   5篇
排序方式: 共有1647条查询结果,搜索用时 62 毫秒
1.
Aqueous self-assembly of short peptides has attracted growing attention for the construction of supramolecular materials for various bioapplications. Herein, we describe how the thermolysin-assisted biocatalytic construction of a dipeptide hydrazide from an N-protected amino acid and an amino acid hydrazide leads to the formation of thermally stable supramolecular hydrogels. In addition, we demonstrate the post-assembly modification of the supramolecular architectures constructed in situ tethering hydrazide groups as a chemical handle by means of fluorescence imaging.  相似文献   
2.
We report the recent development on the SUSY calculations with the help of GRACE system. GRACE/SUSY/1LOOP is the computer code which can generate Feynman diagrams in the MSSM automatically and compute one-loop amplitudes in the numerical way. We present new results of various two-body decay widths and chargino pair production at ILC (international linear collider) at one-loop level.   相似文献   
3.
Let Cld AW (X) be the hyperspace of nonempty closed subsets of a normed linear space X with the Attouch–Wets topology. It is shown that the space Cld AW (X) and its various subspaces are AR's. Moreover, if X is an infinite-dimensional Banach space with weight w(X) then Cld AW (X) is homeomorphic to a Hilbert space with weight 2 w(X).  相似文献   
4.
A special family of partitions occurs in two apparently unrelated contexts: the evaluation of one-dimensional configuration sums of certain RSOS models, and the modular representation theory of symmetric groups or their Hecke algebras Hm. We provide an explanation of this coincidence by showing how the irreducible Hm-modules which remain irreducible under restriction to Hm_1 (Jantzen–Seitz modules) can be determined from the decomposition of a tensor product of representations sln.  相似文献   
5.
6.
The mathematical model for predicting the precision, limit of detection (LOD) and range of quantitation (ROQ) in a competitive enzyme-linked immunosorbent assay (ELISA) proposed by Hayashi et al. (Anal. Chem., 2004, 76, 1295) was validated. The model describes the relative standard deviation (RSD) of concentration estimates by the RSDs of pipetting volumes of analyte, enzyme-conjugated antigen, antibody and substrate solutions, and the standard deviation (SD) of inherent absorbances between the wells in an ELISA plate. For 6 kinds of direct competitive ELISA kits, the LOD and ROQ predicted by the model agreed well with those obtained by experiments with real samples. It was also confirmed that the model is applicable to the prediction of uncertainty that depends on the pipetting error of the viscous antiserum solution. The model was demonstrated to be useful for estimating the LOD and ROQ of competitive ELISA.  相似文献   
7.
The Voronoi diagram in a flow field is a tessellation of water surface into regions according to the nearest island in the sense of a “boat-sail distance”, which is a mathematical model of the shortest time for a boat to move from one point to another against the flow of water. The computation of the diagram is not easy, because the equi-distance curves have singularities. To overcome the difficulty, this paper derives a new system of equations that describes the motion of a particle along the shortest path starting at a given point on the boundary of an island, and thus gives a new variant of the marker-particle method. In the proposed method, each particle can be traced independently, and hence the computation can be done stably even though the equi-distance curves have singular points.  相似文献   
8.
A modified light-fluorous Mukaiyama reagent bearing a C8F17 tag was prepared and examined in ester and amide forming condensation reactions. Following the reactions, the desired product was effectively separated from the fluorous pyridone by-product using a simple fluorous solid phase extraction.  相似文献   
9.
 A percolation problem on Sierpinski carpet lattices is considered. It is obtained that the critical probability of oriented percolation is equal to 1. In contrast it was already shown that the critical probability p c of percolation is strictly less than 1 in Kumagai [9]. This result shows a difference between fractal-like lattice and ℤ d lattice. Received: 15 May 2002 / Revised version: 11 October 2002 / Published online: 21 February 2003 Mathematics Subject Classification (2000): Primary: 60K35, 82B43; Secondary: 82B26  相似文献   
10.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号