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   1250篇
  免费   52篇
  国内免费   7篇
化学   809篇
晶体学   2篇
力学   28篇
数学   181篇
物理学   289篇
  2023年   7篇
  2022年   6篇
  2021年   44篇
  2020年   33篇
  2019年   31篇
  2018年   14篇
  2017年   16篇
  2016年   57篇
  2015年   27篇
  2014年   66篇
  2013年   79篇
  2012年   66篇
  2011年   95篇
  2010年   56篇
  2009年   45篇
  2008年   57篇
  2007年   68篇
  2006年   55篇
  2005年   47篇
  2004年   48篇
  2003年   31篇
  2002年   41篇
  2001年   31篇
  2000年   14篇
  1999年   9篇
  1998年   8篇
  1996年   18篇
  1995年   17篇
  1994年   13篇
  1993年   9篇
  1992年   7篇
  1991年   12篇
  1990年   6篇
  1989年   8篇
  1988年   5篇
  1986年   9篇
  1985年   6篇
  1983年   5篇
  1982年   5篇
  1981年   6篇
  1977年   8篇
  1975年   6篇
  1974年   6篇
  1937年   6篇
  1936年   5篇
  1934年   10篇
  1933年   9篇
  1932年   8篇
  1931年   7篇
  1929年   5篇
排序方式: 共有1309条查询结果,搜索用时 31 毫秒
1.
Active anodes, especially those consisting of metal mixed oxides (MMOs) containing Ru and/or Ir oxides, have been applied in the treatment of wastewater, especially when chloride ions are present. Their characteristics continuously drive the study of applications of these materials, be they in the degradation of different organic molecules, the preparation of new electrode materials and in the association of various processes to increase pollutant removal. Thus, this brief review aims to present some of the recent advances in the application of active anode materials in environmental electrochemistry. Focussing on the 2018–2020 period, it is possible to note many applied studies, using commercially available materials, covering a wide range of target pollutants. Still other studies aim to modify the catalyst surfaces to increase the mineralization capacity, and the use of these anodes in the production of free chlorine species to mediate indirect organic reduction is observed.  相似文献   
2.
A fully quantitative theory of the relationship between protein conformation and optical spectroscopy would facilitate deeper insights into biophysical and simulation studies of protein dynamics and folding. In contrast to intense bands in the far-ultraviolet, near-UV bands are much weaker and have been challenging to compute theoretically. We report some advances in the accuracy of calculations in the near-UV, which were realised through the consideration of the vibrational structure of the electronic transitions of aromatic side chains.  相似文献   
3.
4.
Letg:U→ℝ (U open in ℝn) be an analytic and K-subanalytic (i. e. definable in ℝ an K , whereK, the field of exponents, is any subfield ofℝ) function. Then the set of points, denoted Σ, whereg does not admit an analytic extension is K-subanalytic andg can be extended analytically to a neighbourhood of Ū\∑. Partially supported by the European RTN Network RAAG (contract no. HPRN-CT-00271)  相似文献   
5.
Summary. Several nitroflavone derivatives were synthesized by cyclodehydrogenation of 2′-hydroxychalcones and by the Baker-Venkataraman approach, starting from 2′-hydroxyacetophenones and benzoic acid derivatives. Nitroflavones synthesised by the first synthetic approach were obtained in better global yields than those obtained by the later method. The structures of all new compounds were elucidated by microanalyses, 1D and 2D NMR, IR, and mass spectroscopic measurements.  相似文献   
6.
It is shown that any local quantum field theory admits thermodynamical equilibrium states (KMS-states) for all positive temperatures provided it satisfies a nuclearity condition, proposed by Wichmann and one of the authors, which restricts the admissible number of local degrees of freedom.Dedicated to E. H. Wichmann on the occasion of his 60th birthday  相似文献   
7.
8.
We have measured the lifetimes of hadronically produced charged and neutralD mesons using silicon microstrip detectors and an active silicon target in the NA32 spectrometer at the CERN SPS. We obtainτ D± = (10.9± 1.5 1.9 )·10?13s andτ D (?)10 = (4.2±0.5)·10?13s based on 59 and 90 fully reconstructed decays respectively, giving a ratioτ D±/τ D (?)10 of 2.6 ±0.5.  相似文献   
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