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   685篇
  免费   14篇
  国内免费   1篇
化学   506篇
晶体学   6篇
力学   17篇
数学   62篇
物理学   109篇
  2021年   3篇
  2020年   8篇
  2019年   7篇
  2018年   5篇
  2017年   8篇
  2016年   10篇
  2015年   10篇
  2014年   15篇
  2013年   29篇
  2012年   38篇
  2011年   41篇
  2010年   24篇
  2009年   20篇
  2008年   43篇
  2007年   49篇
  2006年   45篇
  2005年   35篇
  2004年   33篇
  2003年   20篇
  2002年   35篇
  2001年   8篇
  2000年   7篇
  1999年   7篇
  1998年   13篇
  1997年   5篇
  1996年   8篇
  1995年   5篇
  1994年   5篇
  1993年   5篇
  1992年   12篇
  1991年   10篇
  1990年   5篇
  1989年   8篇
  1988年   7篇
  1987年   9篇
  1985年   14篇
  1984年   12篇
  1983年   3篇
  1982年   10篇
  1981年   8篇
  1980年   5篇
  1979年   7篇
  1978年   8篇
  1977年   3篇
  1976年   5篇
  1975年   7篇
  1974年   6篇
  1973年   7篇
  1968年   3篇
  1964年   2篇
排序方式: 共有700条查询结果,搜索用时 234 毫秒
1.
We propose a super Lax type equation based on a certain class of Lie superalgebra as a supersymmetric extension of generalized (modified) KdV hierarchy. We are able to construct an infinite set of conservation laws and the consistent time evolution generators for generalized modified super KdV equations. Thefirst few of the conserved currents, the (modified) super KdV equation and the super Miura transformation are worked out explicitly in the case of twisted affine Lie superalgebraOSp(2/2)(2).Partially supported by the Grant-in-Aid for Scientific Research from the Ministry of Education, Science and Culture (#01540246 and #01790203).RIFP will be known as Yukawa Institute for Theoretical Physics from June 8, 1990  相似文献   
2.
Oscillation is found in many biological systems, and among them the enzymatic oscillatory reaction has been well studied using an enzyme solution. We show in this study for the first time that oscillation occurs when catalase is immobilized to controlled pore glass (CPG). The oscillatory wave mode changes with the distance among the CPG, electrode, or dialysis membrane. The lower substrate concentration results in oscillation with a longer period. This tendency agrees with a previous study using an enzyme solution. Furthermore, we show that the oscillation occurs when no dialysis membrane is used. These results show the wider applicability of the system to analysis or novel device fabrication.  相似文献   
3.
This paper gives a condition which implies the nonexistence of parametric statistical procedures with bounded risk or error performance characteristics. Many examples for which such a condition is satisfied are considered.  相似文献   
4.
Paul Finnie  Yoshikazu Homma   《Surface science》2002,500(1-3):437-457
The engineering of many modern electronic devices demands control over a crystal down to the thickness of a single layer of atoms—and future demands will be even more challenging. Such control is achieved by the method of crystal growth known as epitaxy, and that makes this method the subject of intense study. More than that, recent advances are revolutionizing our knowledge of how surfaces grow. In fact, growing surfaces show a beautifully rich variety of phenomena, many of which are only now beginning to be uncovered. In the past few years many surface imaging techniques have been used to give us a close look at how crystals grow—while they are growing. The purpose of this article will be to illustrate some of the ways real surfaces grow and change as revealed by some of the latest in situ microscopic imaging technologies.

It is often said that crystal growth is more of an art than a science. Here we will show that it is emphatically both.  相似文献   

5.
6.
A simple and highly sensitive spectrophotometric method for the determination of anthracycline anticancer agents, such as Daunorubicin hydrochloride (DAU), was established by using aluminum(III) and Chromazurol S (CAS) in a nonionic surfactant micellar medium. In the case of determination of DAU, the apparent molar absorptivity was 1.3 x 10(5) dm3 mol(-1) cm(-1) at 615 nm. Beer's law was obeyed in the concentration range of 0.028 - 2.82 microg ml(-1) for DAU. Owing to no need for solvent extraction, this method could be applied to assays of DAU and related drugs in pharmaceutical preparations.  相似文献   
7.
8.
9.
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