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   6327篇
  免费   192篇
  国内免费   4篇
化学   4055篇
晶体学   26篇
力学   207篇
综合类   9篇
数学   821篇
物理学   1405篇
  2023年   29篇
  2022年   45篇
  2021年   55篇
  2020年   77篇
  2019年   76篇
  2018年   105篇
  2017年   71篇
  2016年   142篇
  2015年   179篇
  2014年   160篇
  2013年   350篇
  2012年   394篇
  2011年   390篇
  2010年   262篇
  2009年   164篇
  2008年   388篇
  2007年   354篇
  2006年   326篇
  2005年   306篇
  2004年   267篇
  2003年   267篇
  2002年   217篇
  2001年   133篇
  2000年   145篇
  1999年   71篇
  1998年   97篇
  1997年   63篇
  1996年   90篇
  1995年   47篇
  1994年   54篇
  1993年   54篇
  1992年   55篇
  1991年   36篇
  1990年   40篇
  1989年   36篇
  1988年   46篇
  1986年   30篇
  1985年   51篇
  1984年   62篇
  1983年   33篇
  1982年   54篇
  1981年   56篇
  1980年   45篇
  1979年   42篇
  1978年   47篇
  1977年   49篇
  1976年   59篇
  1975年   35篇
  1974年   31篇
  1973年   33篇
排序方式: 共有6523条查询结果,搜索用时 0 毫秒
1.
Transition‐metal complexes containing stimuli‐responsive systems are attractive for applications in optical devices, photonic memory, photosensing, as well as luminescence imaging. Amongst them, photochromic metal complexes offer the possibility of combining the specific properties of the metal centre and the optical response of the photochromic group. The synthesis, the electrochemical properties and the photophysical characterisation of a series of donor–acceptor azobenzene derivatives that possess bipyridine groups connected to a 4‐dialkylaminoazobenzene moiety through various linkers are presented. DFT and TD‐DFT calculations were performed to complement the experimental findings and contribute to their interpretation. The position and nature of the linker (ethynyl, triazolyl, none) were engineered and shown to induce different electronic coupling between donor and acceptor in ligands and complexes. This in turn led to strong modulations in terms of photoisomerisation of the ligands and complexes.  相似文献   
2.
3.
4.
The PARRNe facility has been used to produce neutron-rich isotopes 83,84Gaby the ISOL method. Their decay has been studied, and β-γ coincidence and γ-γ coincidence data were collected as a function of time. The first two excited levels in 83Ge and the first excited level in 84Ge have been measured for the first time.  相似文献   
5.
The basic features of a chemical measurement   总被引:2,自引:0,他引:2  
  相似文献   
6.
In this paper we use real analysis techniques to establish a new real Paley-Wiener theorems for the Fourier-Bessel transform associated with the Weinstein operator. More precisely we characterize the C -functions whose image under the Fourier-Bessel transform are functions with compact support through an L p growth condition, p ∈ [1, +∞] and we give another version of the real Paley-Wiener theorem for L 2-functions.  相似文献   
7.
8.
We report on the status of the LPCTrap experiment, devoted to measure the β–ν angular correlation in the pure Gamow–Teller decay of 6He. This measurement is motivated by the search for the presence of tensor type contributions to the weak interaction. The 6He ions are confined in a novel transparent Paul trap. The β particles and the recoil ions are detected in coincidence to deduce the angular correlation parameter. The commissioning run performed in 2005 has given the proof of principle of this experiment. Up to 105 coincidences were recorded during a second run in 2006.  相似文献   
9.
For generic families of vector fields or transformations, normally hyperbolic invariant products of spheres appear near partially elliptic rest points. To cite this article: M. Kammerer-Colin de Verdière, C. R. Acad. Sci. Paris, Ser. I 339 (2004).  相似文献   
10.
In this Note, we propose three formulations of a model describing a quasi-neutral plasma with non-vanishing current. In order to study and compare the numerical efficiency of each formulation, two test-problems are implemented in one dimension. The first is a periodic perturbation of a uniform stationary plasma. The second is a case of plasma expansion in vacuum between two electrodes. To cite this article: P. Crispel et al., C. R. Acad. Sci. Paris, Ser. I 338 (2004).  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