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   520篇
  免费   15篇
  国内免费   3篇
化学   289篇
晶体学   4篇
力学   13篇
数学   35篇
物理学   197篇
  2023年   13篇
  2022年   18篇
  2021年   16篇
  2020年   16篇
  2019年   21篇
  2018年   13篇
  2017年   17篇
  2016年   21篇
  2015年   12篇
  2014年   28篇
  2013年   48篇
  2012年   25篇
  2011年   34篇
  2010年   22篇
  2009年   18篇
  2008年   25篇
  2007年   13篇
  2006年   10篇
  2005年   9篇
  2004年   17篇
  2003年   2篇
  2002年   11篇
  2001年   3篇
  1998年   7篇
  1996年   6篇
  1995年   7篇
  1994年   9篇
  1993年   8篇
  1992年   14篇
  1991年   5篇
  1990年   8篇
  1989年   4篇
  1988年   3篇
  1987年   3篇
  1986年   6篇
  1985年   4篇
  1984年   3篇
  1983年   3篇
  1982年   4篇
  1981年   3篇
  1980年   5篇
  1979年   2篇
  1978年   2篇
  1977年   5篇
  1976年   3篇
  1975年   4篇
  1974年   1篇
  1973年   3篇
  1972年   2篇
  1970年   1篇
排序方式: 共有538条查询结果,搜索用时 31 毫秒
91.
Oximes of ketones and aldehydes are efficiently deprotected with glyoxylic acid in an aqueous medium at room temperature. Oximes can be cleaved selectively in the presence of a TBDMS group. This method is high yielding, fast, clean, safe, cost effective, and therefore very suitable for practical organic synthesis.  相似文献   
92.
Treatment through a combination of drugs involving cyclin D-dependent kinase inhibitors like abemaciclib and aromatase inhibitor like letrozole proved to be a potential therapeutic regimen and first-line treatment in estrogen receptor-positive breast cancer. In this study, we developed a simple and simultaneous RP-HPLC bioanalytical method for quantifying abemaciclib and letrozole in rat plasma. Abemaciclib and letrozole were separated on Zorbax Eclipse C18 column employing a gradient elution method comprising 10 mM ammonium acetate (pH 5) and acetonitrile as mobile phase. The method was found to have acceptable selectivity, accuracy (97.20–118.17%), precision (1.10–9.39%) and stability in the validation experiment performed as per the US Food and Drug Administration guidelines. The method sensitivity was low at a concentration level of 100 ng/ml. The applicability of the method has been verified through a single-dose oral pharmacokinetic study in rat. The developed method will be useful to quantitate the analytes in rat plasma samples of different preclinical studies including their pharmacokinetic drug–drug interactions in the future. To date, no method has been reported for the quantification of abemaciclib and letrozole simultaneously in any type of biological matrices. Therefore, this study makes a definite significant contribution in the field of bioanalytical research.  相似文献   
93.
Experimental results on multiplicity distributions for full phase space and in different pesudorapidity windows of charged secondary particles produced in proton-nucleon collisions at 800 GeV are presented and discussed. It is found that all these multiplicity distributions are well described by negative binomial distributions. We interpret our results on the basis of clan model. The bin size dependence of multiplicity distribution of charged secondary particles in proton-nucleon interactions is analysed in terms of multifractals. The values of generalised dimensions obtained from fitted distributions show a good agreement with those obtained from the data.  相似文献   
94.
Variousworkershavereportedthepreparation,chemicalandphysicalpropertiesofvariousSchiffbases犤1-5犦.Schiffbasesareknowntobeimportantduetotheirapplicationsintheprepa-rationofdyes,liquidcrystalsandpowerfulcorrosionin-hibitors.Furthermore,theyareusedinthemecha…  相似文献   
95.
Superconducting oxide-copper monoliths have been fabricated by shock-wave loading using cylindrical and plane geometries. Bulk densities up to 96% T.D. have been obtained by varying detonation parameters. The superconducting properties, interface bonding and microstructure of the compacts have been evaluated.  相似文献   
96.
Results are presented for study of nonlinear magnetization of a sintered YBa2Cu3O7−y pellet of different thickness of a sample subjected to very low magnetic field. On cooling the sample belowT c in zero field a change, in the oscillatory structure of harmonics in increasing dc field is observed in very low ac magnetic field. The effect of finiteness of the sample on the oscillatory structure and on the hysteresis of harmonics is also studied. The results are explained qualitatively.  相似文献   
97.
98.
99.
100.
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