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   325篇
  免费   14篇
  国内免费   35篇
化学   178篇
晶体学   2篇
力学   2篇
综合类   1篇
数学   113篇
物理学   78篇
  2024年   2篇
  2023年   8篇
  2022年   15篇
  2021年   9篇
  2020年   13篇
  2019年   14篇
  2018年   9篇
  2017年   9篇
  2016年   8篇
  2015年   7篇
  2014年   5篇
  2013年   23篇
  2012年   10篇
  2011年   13篇
  2010年   14篇
  2009年   21篇
  2008年   20篇
  2007年   19篇
  2006年   18篇
  2005年   14篇
  2004年   12篇
  2003年   8篇
  2002年   13篇
  2001年   4篇
  2000年   4篇
  1999年   3篇
  1998年   6篇
  1997年   3篇
  1996年   11篇
  1995年   8篇
  1994年   8篇
  1993年   6篇
  1992年   5篇
  1991年   1篇
  1988年   2篇
  1987年   1篇
  1986年   1篇
  1985年   5篇
  1984年   4篇
  1982年   3篇
  1981年   2篇
  1980年   2篇
  1979年   1篇
  1978年   1篇
  1977年   4篇
  1976年   4篇
  1973年   1篇
排序方式: 共有374条查询结果,搜索用时 15 毫秒
41.
With a method close to that of Kirillov [4], we define sequences of vector fields on the set of univalent functions and we construct systems of partial differential equations which have the sequence of the Faber polynomials (Fn) as a solution. Through the Faber polynomials and Grunsky coefficients, we obtain the generating functions for some of the sequences of vector fields.  相似文献   
42.
43.
In this paper we obtain upper and lower bounds for the unique positive roots of certain sequences of polynomials. The results are then applied to the determination of theR-order of iterative numerical processes.  相似文献   
44.
In [L. Lebtahi, Lie algebra on the transverse bundle of a decreasing family of foliations, J. Geom. Phys. 60 (2010), 122–133], we defined the transverse bundle VkVk to a decreasing family of kk foliations FiFi on a manifold MM. We have shown that there exists a (1,1)(1,1) tensor JJ of VkVk such that Jk≠0Jk0, Jk+1=0Jk+1=0 and we defined by LJ(Vk)LJ(Vk) the Lie Algebra of vector fields XX on VkVk such that, for each vector field YY on VkVk, [X,JY]=J[X,Y][X,JY]=J[X,Y].  相似文献   
45.
46.
The Hamiltonian of the zinc-blende quantum rods in the framework of eight-band effective-mass approximation in the presence of external homogeneous magnetic field is given. The electronic structure, optical properties and electron g factors of GaAs quantum rods are investigated. We found that the electron g factors are very sensitively dependent on the dimensions of the quantum rods. As some of the three dimensions increase, the electron g factors decrease. The more the dimensions increase, the more the electron g factors decrease. The dimensions perpendicular to the direction of the magnetic field affect the electron g factors more than the other dimension.  相似文献   
47.
In this paper we propose a new definition of prime ends for domains in metric spaces under rather general assumptions. We compare our prime ends to those of Carathéodory and Näkki. Modulus ends and prime ends, defined by means of the pp-modulus of curve families, are also discussed and related to the prime ends. We provide characterizations of singleton prime ends and relate them to the notion of accessibility of boundary points, and introduce a topology on the prime end boundary. We also study relations between the prime end boundary and the Mazurkiewicz boundary. Generalizing the notion of John domains, we introduce almost John domains, and we investigate prime ends in the settings of John domains, almost John domains and domains which are finitely connected at the boundary.  相似文献   
48.
通过水热法制备了一种复合光催化剂Bi_2WO_6/UiO-66,探究了模板剂乙酸(CH_3COOH)对Ui O-66形貌的影响和2种中心元素Bi与Zr的不同物质的量之比对光催化性能的影响。通过XRD、SEM、N_2吸附-脱附、UV-Vis DRS、XPS等对催化剂的物相、形貌、比表面积、光吸收性能、元素组成等进行表征。实验结果表明,当n_(Bi)∶n_(Zr)=2∶1时,Bi_2WO_6/UiO-66对罗丹明B(RhB)的光催化活性最高,可见光照射50 min后,RhB的相对浓度降低98.5%。经过5次循环利用实验,催化剂的光催化活性没有明显下降,说明复合光催化剂的稳定性高。根据自由基捕获实验证明了空穴(h~+)为光催化中起决定性作用的活性物质,结合电化学测试以及UV-Vis DRS表征提出了可能的光催化降解机理。  相似文献   
49.
Avraham Gal   《Nuclear Physics A》2008,804(1-4):13
The major contributions of Richard H. Dalitz to hypernuclear physics, since his first paper in 1955 to his last one in 2005 covering a span of 50 years during which he founded and led the theoretical study of hypernuclei, are reviewed from a personal perspective. Topical remarks on the search for quasi-bound -nuclear states and on kaon condensation are made.  相似文献   
50.
Along with the rapid development of industry, VOCs gradually move into the spotlight, and now become a kind of harmful environmental pollutants that cannot be overlooked. This paper introduces the hazards of VOCs and the common catalytic combustion catalysts, noble metal catalysts and non-noble metal catalysts, for the elimination of VOCs. Perovskite catalysts, as one of the non-noble catalysts, play an important role in the field of catalytic combustion in recent years. According to the classification of elements doping in perovskites, the research achievements in the past five years were analyzed and reviewed. In addition, this paper also analyzes and elaborates the reaction kinetics and QSAR/QSPR models for the introduction of structural properties and reaction mechanisms.  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