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   71篇
  免费   2篇
化学   43篇
力学   1篇
数学   5篇
物理学   24篇
  2017年   1篇
  2016年   5篇
  2014年   2篇
  2013年   6篇
  2012年   2篇
  2011年   3篇
  2010年   1篇
  2009年   2篇
  2008年   5篇
  2007年   2篇
  2006年   3篇
  2005年   3篇
  2004年   1篇
  2003年   2篇
  2002年   3篇
  2001年   2篇
  2000年   4篇
  1999年   1篇
  1995年   1篇
  1993年   1篇
  1992年   2篇
  1991年   1篇
  1990年   1篇
  1989年   1篇
  1988年   3篇
  1985年   2篇
  1984年   2篇
  1982年   2篇
  1981年   1篇
  1976年   1篇
  1973年   1篇
  1970年   1篇
  1969年   1篇
  1968年   1篇
  1967年   1篇
  1935年   1篇
  1928年   1篇
排序方式: 共有73条查询结果,搜索用时 15 毫秒
51.
52.
53.
Let ?? be a finite dimensional complex simple Lie superalgebra of Cartan type and A be a commutative, associative algebra with unity over ?. We refer to the Lie superalgebras of the form ?? ? A as Cartan map superalgebras. In this paper, following Bagci and Chamberlin (J. of Pure and Applied Algebra 218(8), 1563–1576, 2014), we define an integral form for the universal enveloping algebra of the Cartan map superalgebras, and exhibit an explicit integral basis for this integral form.  相似文献   
54.
The extraction of strontium and cesium ions from high ionic strength acid, base, and salt solutions into an organic extractant consisting of alkyl cobalt dicarbollide and polyethylene glycol (PEG) in diethylbenzene was investigated. Adding hexaethylene glycol or PEG-400 improved the strontium extraction ≥100-fold, while cesium extraction was decreased at high PEG concentrations. The extractions are rapid and selective, even in the presence of molar concentrations of sodium ion, suggesting that alkyl cobalt dicarbollide extractants are useful for the treatment of alkaline nuclear wastes. A method for the synthesis of tetra-n-hexyl(cobalt dicarbollide) is described.  相似文献   
55.
56.
The history of absolute measurements of gravity is mentioned and the reasons for making absolute measurements are indicated. The principles and main advantages and difficulties of the main method—reversible pendulum, free fall, symmetrical free motion—are discussed and examples of each method are described. Problems of comparison of different determinations and of estimating systematic errors are considered.  相似文献   
57.
This work introduces a model, solvation model 6 with temperature dependence (SM6T), to predict the temperature dependence of aqueous free energies of solvation for compounds containing H, C, and O in the range 273-373 K. In particular, we extend solvation model 6 (SM6), which was previously developed (Kelly, C. P.; Cramer, C. J.; Truhlar, D. G. J. Chem. Theory Comput. 2005, 1, 1133) for predicting aqueous free energies of solvation at 298 K, to predict the variation of the free energy of solvation relative to 298 K. Also, we describe the database of experimental aqueous free energies of solvation for compounds containing H, C, and O that was used to parametrize and test the new model. SM6T partitions the temperature dependence of the free energy of solvation into two components: the temperature dependence of the bulk electrostatic contribution to the free energy of solvation, which is computed using the generalized Born equation, and the temperature dependence of first-solvation-shell effects which is modeled using a parametrized solvent-exposed surface-area-dependent term. We found that SM6T predicts the temperature dependence of aqueous free energies of solvation with a mean unsigned error of 0.08 kcal/mol over our entire database, whereas using the experimental value at 298 K produces a mean unsigned error of 0.53 kcal/mol.  相似文献   
58.
59.
3-Alkoxy enolates of γ-butryrolactones are stereoselectively methylated at C-2 to give the corresponding trans-3-hydroxy-2-methyl-γ-butyrolactones.  相似文献   
60.
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