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   194篇
  免费   0篇
  国内免费   1篇
化学   84篇
力学   10篇
数学   24篇
物理学   77篇
  2017年   3篇
  2016年   1篇
  2015年   3篇
  2014年   2篇
  2013年   5篇
  2012年   5篇
  2011年   12篇
  2010年   18篇
  2009年   6篇
  2008年   20篇
  2007年   17篇
  2006年   5篇
  2005年   7篇
  2004年   6篇
  2003年   5篇
  2002年   6篇
  2001年   4篇
  2000年   2篇
  1999年   1篇
  1998年   3篇
  1997年   4篇
  1996年   4篇
  1995年   3篇
  1994年   2篇
  1993年   3篇
  1992年   2篇
  1990年   2篇
  1989年   1篇
  1988年   2篇
  1987年   4篇
  1986年   2篇
  1985年   6篇
  1984年   4篇
  1983年   4篇
  1981年   3篇
  1980年   2篇
  1979年   2篇
  1978年   3篇
  1977年   7篇
  1976年   1篇
  1973年   2篇
  1960年   1篇
排序方式: 共有195条查询结果,搜索用时 46 毫秒
51.
52.
53.
Translated from Matematicheskie Zametki, Vol. 47, No. 3, pp. 3–10, March, 1990.  相似文献   
54.
55.
56.
Ferrocenylmethylation and -ferrocenylethylation of indazole were carried out for the first time. Both reactions afforded two isomers, which were characterized by physical and physicochemical methods, among them by X-ray diffraction analysis. 1-(-Ferrocenylethyl)indazole is thermally more stable than the 2-substituted isomer. Both isomers serve as ferrocenylalkylating agents with respect to s-triazole.  相似文献   
57.
In this paper topological invariants of dynamics of scalar parabolic equations are defined. Conservation of these invariants causes persistence of complex spatially chaotic patterns in the dynamics. It implies, in particular, the existence of extremely many stable essentially different spatially complex solutions of scalar semilinear parabolic, elliptic and hyperbolic equations in the situation when coefficients of equations depend on the spatial variable strongly enough and the domain is large or unbounded, the number of different solutions exponentially depends on the volume of domain. Another implication of the conserved quantities is persistence of complexity of solutions in the dynamics.  相似文献   
58.
A cholesterol‐based liquid crystal monomer, diethylene glycol cholesteryl ether acrylate (DEGCholA), has been successfully polymerized by atom transfer radical polymerization (ATRP) for the first time. Appropriate experimental conditions to control the polymerization of DEGCholA have been investigated using a model initiator (ethyl 2‐bromoisobutyrate) in tetrahydrofuran (THF) or toluene at 60 °C. Well‐controlled ATRP of DEGCholA was obtained using N,N,N′,N′,N″‐pentamethyldiethylenetriamine as ligand in THF at 60 °C. These conditions were then applied to initiate the ATRP of DEGCholA from multifunctional macroinitiators based on dextran. Using a protection/deprotection synthetic scheme, novel graft glycopolymers (Dex‐g‐PDEGCholA) have been synthesized. The mesomorphic properties of DEGCholA, PDEGCholA, and Dex‐g‐PDEGCholA have been studied by thermal polarizing optical microscopy, differential scanning calorimetry, and X‐ray scattering. PDEGCholA and Dex‐g‐PDEGCholA show an interdigitated smectic A phase (SmAd) between Tg (~30 °C) and around 170 °C. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2013 , 51, 3829–3839  相似文献   
59.
60.
Exponential attractors of reaction-diffusion systems in an unbounded domain   总被引:3,自引:0,他引:3  
We consider reaction-diffusion systems in unbounded domains, prove the existence of expotential attractors for such systems, and estimate their fractal dimension. The essential difference with the case of a bounded domain studied before is the continuity of the spectrum of the linear part of the equations. This difficulty is overcome by systematic use of weighted Sobolev spaces.  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