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   2590篇
  免费   82篇
  国内免费   8篇
化学   1931篇
晶体学   15篇
力学   25篇
综合类   1篇
数学   139篇
物理学   569篇
  2022年   18篇
  2021年   25篇
  2020年   35篇
  2019年   46篇
  2018年   32篇
  2017年   18篇
  2016年   57篇
  2015年   45篇
  2014年   54篇
  2013年   106篇
  2012年   145篇
  2011年   186篇
  2010年   83篇
  2009年   103篇
  2008年   158篇
  2007年   164篇
  2006年   128篇
  2005年   121篇
  2004年   122篇
  2003年   100篇
  2002年   86篇
  2001年   52篇
  2000年   34篇
  1999年   43篇
  1998年   28篇
  1997年   30篇
  1996年   36篇
  1995年   28篇
  1994年   25篇
  1993年   31篇
  1992年   33篇
  1991年   31篇
  1990年   29篇
  1989年   25篇
  1988年   37篇
  1987年   28篇
  1986年   15篇
  1985年   27篇
  1984年   35篇
  1983年   19篇
  1982年   17篇
  1981年   23篇
  1980年   25篇
  1979年   23篇
  1978年   24篇
  1977年   24篇
  1976年   13篇
  1975年   13篇
  1974年   16篇
  1969年   11篇
排序方式: 共有2680条查询结果,搜索用时 15 毫秒
1.
Journal of Thermal Analysis and Calorimetry - Nitrocellulose (NC) is prone to spontaneous decomposition with exothermic heat release and thus is generally evaluated for stability during the storage...  相似文献   
2.
Journal of Radioanalytical and Nuclear Chemistry - Extraction chromatography flow-sheet employing octyl(phenyl)-N,N-diisobutylcarbonoylmethylphosphine oxide and bis(2-ethylhexyl) hydrogen phosphate...  相似文献   
3.
Many operators in Banach spaces occur as the integration operator of a suitable vector measure; their compactness is completely described in [19]. However, many important spaces X in analysis (and integration operators in such spaces) do not fall into this scheme because X is not normable. Characterizing the compactness of integration operators in this setting is the aim of this note. The methods and techniques employed are quite different to the Banach space arguments used in [19].  相似文献   
4.
We shall give a direct proof of the independence result of a Buchholz style-Hydra Game on labeled finite trees. We shall show that Takeuti-Arai's cut-elimination procedure of and of the iterated inductive definition systems can be directly expressed by the reduction rules of Buchholz's Hydra Game. As a direct corollary the independence result of the Hydra Game follows. Received: August 23, 1994 / Revised: July 24, 1995 and May 9, 1996  相似文献   
5.
6.
A multi-layer chip inductor (MCI) was fabricated using polycrystalline Li–Zn–Cu–Mn ferrite and the green-sheet technique, and its complex impedance spectrum was evaluated with the help of numerical calculations. The complex impedance spectra of the MCI component using Ni–Zn–Cu ferrite, which have been widely used for this application, were very sensitive to the residual stress and deviated much from the calculated values; however, it was found that the complex impedance spectrum of the MCI component using Li–Zn–Cu–Mn ferrite is quite well reproduced by calculation, where the complex permittivity and permeability of the polycrystalline ferrite as well as the MCI dimensions, were used. It implied that the magneto-striction effect was negligible in case of MCI using Li–Zn–Cu–Mn ferrite, and that the difference was related to magneto-strictive coefficient of the polycrystalline ferrite. Consequently, utilization of Li–Zn–Cu–Mn ferrite enabled us to easily design the complex impedance of MCI component.  相似文献   
7.
8.
This is summary of the activities of the working group on collider physics in the IXth Workshop on High Energy Physics Phenomenology (WHEPP-9) held at the Institute of Physics, Bhubaneswar, India in January 2006. Some of the work subsequently done on these problems by the subgroups formed during the workshop is included in this report.  相似文献   
9.
Asymmetric Horner-Wadsworth-Emmons reactions of selected meso-α-dicarbonyl compounds with chiral phosphonate reagents, which possessed axially dissymmetric 1,1′-bi-2- or 8-naphthol at the carboxylate moiety as a chiral auxiliary, were examined. The reactions proceeded smoothly with good chemical yields as well as with high diastereoselectivities. Z-olefins were preferentially formed, and it was found that the free hydroxy group at the 2′- or 8′-position on the naphthalene ring plays a crucial role in the high diastereoselectivity, probably due to a complex-induced proximity effect. Mechanistic considerations are also described.  相似文献   
10.
This paper presents a new scheduling method for manufacturing system based on the Timed Petri Net model and a reactive fast graph search algorithm. The following two typical problems are addressed in this paper. (1) Minimization of the maximum completion time. (2) Minimization of the total tardiness. As for the problem (1), a new search algorithm which combines the RTA and a rule-based supervisor is proposed. As for problem (2), the original Petri Net model is converted to its reverse model and the algorithm developed for the problem (1) is applied, regarding the due date as the starting time in the reverse model. Some numerical experiments are carried out to demonstrate usefulness of our algorithm.  相似文献   
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