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   151篇
  免费   2篇
  国内免费   29篇
化学   7篇
晶体学   1篇
力学   5篇
综合类   3篇
数学   161篇
物理学   5篇
  2023年   1篇
  2022年   2篇
  2020年   2篇
  2019年   2篇
  2018年   4篇
  2017年   1篇
  2016年   3篇
  2015年   3篇
  2014年   2篇
  2013年   7篇
  2012年   6篇
  2011年   6篇
  2010年   4篇
  2009年   3篇
  2008年   16篇
  2007年   16篇
  2006年   10篇
  2005年   7篇
  2004年   6篇
  2003年   13篇
  2002年   8篇
  2001年   6篇
  2000年   8篇
  1999年   9篇
  1998年   7篇
  1997年   12篇
  1996年   4篇
  1995年   3篇
  1993年   2篇
  1991年   1篇
  1990年   5篇
  1987年   1篇
  1986年   1篇
  1983年   1篇
排序方式: 共有182条查询结果,搜索用时 296 毫秒
31.
Here we report a facile strategy of fabricating multifunctional polyacrylamide(PAM) hydrogels based on hybrid graphene oxide (GO) sheets and carbon nanotubes (CNTs). Compared to original PAM hydrogels cross-linked chemically with N,N-methylenebisacrylamide (BIS), the hybrid hydrogels exhibit high mechanical strength (strength > 90?kPa and broken strain > 2000%), well adhesion, environmental stability, dye-loading capacity, and excellent self-healing property. This study provides a new insight for the preparation of functionalized hydrogels with carbon nano-materials, and the resultant material shows very promising performance for a range of applications.  相似文献   
32.
Let X be a strongly pseudoconvex compact 3-dimensional CR manifolds which bounds a complex variety with isolated singularities in some CN. The weighted dual graph of the exceptional set of the minimal good resolution of V is a CR invariant of X; in case X has a tranversal holomorphic S1 action, we show that it is a complete topological invariant of except for two special cases. When X is a rational CR manifolds, we give explicit algebraic algorithms to compute the graph invariant in terms of the ring structure of k=0 mk/mk+1, where m is the maximal ideal of each singularity. An example is computed explicitly to demonstrate how the algorithms work.  相似文献   
33.
A necessary and sufficient condition for the boundedness of the operator: $(T_{s,u,u} f)(\xi ) = h^{u + \tfrac{v}{a}} (\xi )\smallint _{\Omega _a } h^s (\xi ')K_{s,u,v} (\xi ,\xi ')f(\xi ')dv(\xi ') on L^p (\Omega _a ,dv_\lambda ),1< p< \infty $ , is obtained, where $\Omega _a = \left\{ {\xi = (z,w) \in \mathbb{C}^{n + m} :z \in \mathbb{C}^n ,w \in \mathbb{C}^m ,|z|^2 + |w|^{2/a}< 1} \right\},h(\xi ) = (1 - |z|^2 )^a - |w|^2 $ andK x,u,v (ξ,ξ′).This generalizes the works in literature from the unit ball or unit disc to the weakly pseudoconvex domain ω a . As an appli cation, it is proved thatf?L H p a ,dv λ) implies $h\tfrac{{|a|}}{a} + |\beta |(\xi )D_2^a D_z^\beta f \in L^p (\Omega _a ,dv_\lambda ),1 \leqslant p< \infty $ , for any multi-indexa=(α1,?,α n and ß = (ß1, —ß). An interesting question is whether the converse holds.  相似文献   
34.
We shall introduce 1-type Lipschitz multifunctions from ℝ into generalized 2-normed spaces, and give some results about their 1-type Lipschitz selections.   相似文献   
35.
36.
In this paper we extend some results of the paper [M. Gromov, G. Henkin, M. Shubin, Holomorphic L2-functions on coverings of pseudoconvex manifolds, Geom. Funct. Anal. 8 (1998) 552-585].  相似文献   
37.
Let be a subharmonic, nonharmonic polynomial and a parameter. Define , a closed, densely defined operator on . If and , we solve the heat equations , u(0,z) = f(z) and , . We write the solutions via heat semigroups and show that the solutions can be written as integrals against distributional kernels. We prove that the kernels are C off of the diagonal {(s, z, w) : s = 0 and z = w} and find pointwise bounds for the kernels and their derivatives.   相似文献   
38.
Let be the algebra of complex matrices, and for denote by and the spectrum and spectral radius of respectively. Let be a domain in containing 0, and let be a holomorphic map. We prove: (1) if for , then for ; (2) if for , then again for . Both results are special cases of theorems expressing the irreducibility of the spectrum near .

  相似文献   

39.
本文讨论作者在〔16〕中提出的广义凸集的各种切锥之间的关系,切锥与正则锥的关系以及切锥的一些代数性质和拓朴性质。  相似文献   
40.
I.IntroductionHah-BanachTheoremisanimportantconclusioninthefunctionialanalysis.Ithaspalyedausefulroleinunsmoothanalysisandotherfields,forexample,theexistanceofthegeneralizedsubdifferentialinI2,3,6]hasbeenproved.Inthispaper,weintroducetheconceptoftheK-convexandtheK-sublinearoftheset-valuedmap,whereKisapointedandclosedandconvexconeinlocallyconvextopologicalvectorspace,andweprovethegeneralizedHahn-BanachTheoreminsection11.Weapplyittothestudyoftheexistenceofsubdifferentialfortheset-valuedmapin…  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