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   15406篇
  免费   412篇
  国内免费   14篇
化学   8160篇
晶体学   130篇
力学   345篇
综合类   1篇
数学   3373篇
物理学   3823篇
  2021年   133篇
  2020年   187篇
  2019年   183篇
  2018年   312篇
  2017年   301篇
  2016年   554篇
  2015年   449篇
  2014年   519篇
  2013年   1094篇
  2012年   749篇
  2011年   958篇
  2010年   566篇
  2009年   514篇
  2008年   661篇
  2007年   621篇
  2006年   529篇
  2005年   355篇
  2004年   377篇
  2003年   313篇
  2002年   303篇
  2001年   229篇
  2000年   226篇
  1999年   174篇
  1998年   162篇
  1997年   149篇
  1996年   150篇
  1995年   136篇
  1994年   124篇
  1993年   126篇
  1992年   147篇
  1991年   122篇
  1990年   139篇
  1989年   131篇
  1988年   132篇
  1987年   123篇
  1985年   169篇
  1984年   183篇
  1983年   145篇
  1982年   155篇
  1981年   142篇
  1980年   141篇
  1979年   146篇
  1978年   160篇
  1977年   126篇
  1976年   150篇
  1975年   132篇
  1974年   145篇
  1965年   164篇
  1964年   174篇
  1955年   122篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
Journal of Solid State Electrochemistry - The addition of nanocrystalline titanium dioxide (P90) to a cathode of Li/S cell enhances its voltammetric charge capacity by 19%, from which only a small...  相似文献   
2.
Czechoslovak Mathematical Journal - We give a complete characterization of closed sets F ? ?2 whose distance function dF:= dist(·, F) is DC (i.e., is the difference of two convex...  相似文献   
3.
Molecular Diversity - The TOPK enzyme (also known as PBK) is a serine-threonine protein kinase that is rarely detected in normal tissues yet is found to be overexpressed and activated in a variety...  相似文献   
4.
Lithuanian Mathematical Journal - We examine the variance of a linear statistic defined on the symmetric group endowed with the Ewens probability. Despite the dependence of the summands, it can be...  相似文献   
5.
Central European Journal of Operations Research - Digital competences are among the most important competences in modern society, with the education system playing a key role in the acquisition of...  相似文献   
6.
Siberian Mathematical Journal - Under consideration is a Dirichlet series depending on a parameter and absolutely convergent in the right half of the critical strip. We prove that...  相似文献   
7.
Laurinčikas  A. 《Mathematical Notes》2022,111(3-4):571-578
Mathematical Notes - In 2007, H. Mishou proved the universality theorem on the joint approximation of a pair of analytic functions by the shifts $$(\zeta(s+i\tau),\zeta(s+i\tau,\alpha))$$ of the...  相似文献   
8.
Journal of Algebraic Combinatorics - In this paper we exploit a relationship between certain pairwise balanced designs with v points and periodic Golay pairs of length v, to classify periodic Golay...  相似文献   
9.
Lithuanian Mathematical Journal - In this paper, we consider estimation of unknown parameters of the tapered Pareto distribution, which belongs to the class of semiheavy distributions, by a sample...  相似文献   
10.
A series of dinuclear half-sandwich Ru(II), Os(II) and Ir(III) complexes [Ru2(μ-Ln)(η6-pcym)2Cl2](PF6)2 ( 1 , 4 ), [Os2(μ-Ln)(η6-pcym)2Cl2](PF6)2 ( 2 , 5 ) and [Ir2(μ-Ln)(η5-Cp*)2Cl2](PF6)2 ( 3 , 6 ), based on 4,4′-biphenyl-based bridging Schiff base ligands N,N′-(biphenyl-4,4′-diyldimethylidyne)bis-2-(pyridin-2-yl)methanamine (L1; for 1 – 3 ) and N,N′-(biphenyl-4,4′-diyldimethylidyne)bis-2-(pyridin-2-yl)ethanamine (L2; for 4 – 6 ) is reported; pcym = 1-methyl-4-(propan-2-yl)benzene, Cp* = pentamethylcyclopentadienyl. The complexes were characterized by relevant analytical techniques (i.e. elemental analysis, FT-IR, NMR, ESI-MS), and their in vitro cytotoxicity was assessed at six cancerous and two non-cancerous (healthy) human cell lines. Overall, complexes 4 – 6 , containing the L2 bridging ligand, revealed higher cytotoxicity as compared with 1 – 3 and, thus, they were studied in greater detail. The best-performing complex 6 exceeded at least twice the in vitro cytotoxicity of cisplatin and showed high selectivity towards the cancer cells over the normal ones, including the primary culture of human hepatocytes. In contrast to cisplatin, complexes 4 – 6 did not induce the cell cycle modification of the treated A2780 human ovarian carcinoma cells (studied by flow cytometry and Western blot analysis). High levels of superoxide anion were induced by complexes 4 – 6 at the A2780 cells. The levels of activated forms of Caspase-3 and Caspase-8 at the A2780 cells treated by Ru(II) complex 4 were comparable with cisplatin, while complexes 5 and 6 had only a minor effect on activation of these caspases.  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