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   2168篇
  免费   53篇
  国内免费   5篇
化学   1585篇
晶体学   12篇
力学   40篇
综合类   1篇
数学   235篇
物理学   353篇
  2023年   15篇
  2022年   23篇
  2021年   55篇
  2020年   47篇
  2019年   35篇
  2018年   36篇
  2017年   37篇
  2016年   55篇
  2015年   41篇
  2014年   64篇
  2013年   108篇
  2012年   117篇
  2011年   128篇
  2010年   82篇
  2009年   85篇
  2008年   109篇
  2007年   118篇
  2006年   95篇
  2005年   98篇
  2004年   86篇
  2003年   60篇
  2002年   66篇
  2001年   32篇
  2000年   27篇
  1999年   18篇
  1998年   18篇
  1997年   23篇
  1996年   23篇
  1995年   32篇
  1994年   31篇
  1993年   28篇
  1992年   24篇
  1991年   16篇
  1990年   21篇
  1989年   17篇
  1988年   28篇
  1987年   23篇
  1986年   9篇
  1985年   14篇
  1984年   19篇
  1983年   21篇
  1982年   22篇
  1981年   23篇
  1980年   20篇
  1979年   11篇
  1978年   21篇
  1977年   14篇
  1976年   14篇
  1975年   13篇
  1974年   10篇
排序方式: 共有2226条查询结果,搜索用时 31 毫秒
1.
Periodica Mathematica Hungarica - We present a tight parametrical Hermite–Hadamard type inequality with probability measure, which yields a considerably closer upper bound for the mean value...  相似文献   
2.
3.
4.
A criterion for the nonexplosion of solutions to semilinear evolution equations on Banach spaces is proved. The result is obtained by applying a modification of the Bihari type inequality to the case of a weakly singular nonlinear integral inequality.  相似文献   
5.
6.
7.
Copolymers of monomers 2,4‐dichlorophenyl methacrylate (2,4‐DMA) and methyl methacrylate (MMA) were synthesized with different monomer feed ratios using toluene as a solvent and 2,2′‐azobisisobutyronitrile (AIBN) as an initiator at 70 °C. The copolymers were characterized by IR‐spectroscopy, and copolymer composition was determined with UV‐spectroscopy. The linearization method of Fineman–Ross was employed to obtain the monomer reactivity ratios. The molecular weights and polydispersity indexes were determined by gel permeation chromatography (GPC). Thermogravimetric analyses of polymers were carried out in nitrogen atmosphere. The homo‐ and copolymers were tested for their antimicrobial properties against selected microorganisms. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 5227–5234, 2004  相似文献   
8.
On‐line coupling of LC and ICP‐MS has been used for fractionation and detection of species of Cu, Fe, I, Se and Zn in human serum. It has been shown that anion exchange chromatography provided better separation capability (both intra‐ and inter‐element) than size‐exclusion chromatography. The mobile phases for ion exchange chromatography consisted of Tris–HNO3 buffer and ammonium salt (nitrate, acetate or formate). Formate was found to be the best mobile phase counter ion, enabling good chromatographic separation, and is acceptable for mass spectrometry too. The quantitative evaluation of element concentrations adhering to individual fractions was performed by the peak area normalization method. The repeatability of results ranged from 3 to 15% (depending on the element concentration level) and represented the main part of the result uncertainty. The accuracy of Cu and Zn fraction determinations was confirmed by comparison with the isotope dilution technique. Copyright © 2006 John Wiley & Sons, Ltd.  相似文献   
9.
Wu  F. Y.  Kunz  H. 《Journal of statistical physics》2004,116(1-4):67-78
We consider a vertex model on the simple-quartic lattice defined by line graphs on the lattice for which there is always an odd number of lines incident at a vertex. This is the odd 8-vertex model which has eight possible vertex configurations. We establish that the odd 8-vertex model is equivalent to a staggered8-vertex model. Using this equivalence we deduce the solution of the odd8-vertex model when the weights satisfy a free-fermion condition. It is found that the free-fermion model exhibits no phase transitions in the regime of positive vertex weights. We also establish the complete equivalence of the free-fermion odd 8-vertex model with the free-fermion 8-vertex model solved by Fan and Wu. Our analysis leads to several Ising model representations of thefree-fermion model with pure 2-spin interactions.  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