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   19706篇
  免费   2204篇
  国内免费   2024篇
化学   2213篇
晶体学   30篇
力学   1720篇
综合类   502篇
数学   13602篇
物理学   5867篇
  2024年   21篇
  2023年   156篇
  2022年   248篇
  2021年   348篇
  2020年   400篇
  2019年   414篇
  2018年   433篇
  2017年   564篇
  2016年   637篇
  2015年   490篇
  2014年   1003篇
  2013年   1270篇
  2012年   1033篇
  2011年   1249篇
  2010年   1113篇
  2009年   1371篇
  2008年   1343篇
  2007年   1433篇
  2006年   1279篇
  2005年   1221篇
  2004年   1002篇
  2003年   911篇
  2002年   762篇
  2001年   707篇
  2000年   651篇
  1999年   559篇
  1998年   506篇
  1997年   478篇
  1996年   346篇
  1995年   284篇
  1994年   236篇
  1993年   179篇
  1992年   153篇
  1991年   126篇
  1990年   136篇
  1989年   91篇
  1988年   85篇
  1987年   75篇
  1986年   67篇
  1985年   82篇
  1984年   66篇
  1983年   46篇
  1982年   63篇
  1981年   59篇
  1980年   38篇
  1979年   34篇
  1978年   30篇
  1977年   26篇
  1976年   30篇
  1973年   21篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
We give uniform estimates of entire functions of exponential type less than having sufficiently small logarithmic sums over real sequences { n } satisfying | n n|L and n+1 n for fixed positive constants L and . We thereby generalize results about logarithmic sums over the set of integers and so-called relatively h-dense sequences.  相似文献   
992.
We show that for below certain critical indices there are functions whose Jacobi or Laguerre expansions have almost everywhere divergent Cesàro and Riesz means of order .

  相似文献   

993.
Let be domains in . Under very mild conditions on we show that there exist holomorphic functions , defined on with the property that is nowhere extendible across , while the graph of over is not complete pluripolar in . This refutes a conjecture of Levenberg, Martin and Poletsky (1992).

  相似文献   

994.
Some improvements and generalizations of Finks results about Hadamards inequality for log-concave functions are given.AMS Subject Classification: 26D07, 26D15, 26A51.  相似文献   
995.
In this paper the question of what classes A of T 0-spaces should be paired with classes of domains in order that all function spaces [AB] for AA and B are -compact domains is considered. It is shown that core compact spaces are paired with bounded complete domains and a class of topological spaces called RW-spaces (with finitely many components) is paired with the class of -compact pointed L-domains (L-domains).  相似文献   
996.
We obtain an asymptotic formula for the number of square-free values among p−1, for primes p?x, and we apply it to derive the following asymptotic formula for L(x), the number of square-free values of the Carmichael function λ(n) for 1?n?x,
  相似文献   
997.
Let Ω be a domain of . As a study of boundary behavior of functions and maps in Ω, we consider “the linear cluster set,” which is the cluster set along segment terminating at a boundary point of Ω. We prove that there exist bounded holomorphic functions and maps defined in Ω which have the linear cluster sets of positive measure at every point of a discrete subset of the boundary of Ω under some conditions.  相似文献   
998.
The work is designated for obtaining asymptotic expansions and determination of structures of the remainder terms that take into consideration large deviations both in the Cramer zone and Linnik power zones for the distribution density function of sums of independent random variables in a triangular array scheme. The result was obtained using general Lemma 6.1 of Saulis and Statuleviius in Limit Theorems for Large Deviations (Kluwer, 1991) and joining the methods of characteristic functions and cumulants. The work extends the theory of sums of random variables and in a special case, improves S. A.Book's results on sums of random variables with weights.  相似文献   
999.
We show that with the weak topology is not an intersection of Borel sets in its Cech-Stone extension (and hence in any compactification). Assuming (CH), this implies that has no continuous injection onto a Borel set in a compact space, or onto a Lindelöf space. Under (CH), this answers a question of Arhangel'ski.

  相似文献   

1000.
We prove the following theorem. Any isometric operator , that acts from the Hilbert space with nonnegative weight to the Hilbert space with nonnegative weight , allows for the integral representation




where the kernels and satisfy certain conditions that are necessary and sufficient for these kernels to generate the corresponding isometric operators.

  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