全文获取类型
收费全文 | 1370篇 |
免费 | 97篇 |
国内免费 | 148篇 |
专业分类
化学 | 224篇 |
晶体学 | 2篇 |
力学 | 78篇 |
综合类 | 42篇 |
数学 | 1021篇 |
物理学 | 248篇 |
出版年
2024年 | 1篇 |
2023年 | 18篇 |
2022年 | 25篇 |
2021年 | 38篇 |
2020年 | 33篇 |
2019年 | 34篇 |
2018年 | 28篇 |
2017年 | 39篇 |
2016年 | 55篇 |
2015年 | 30篇 |
2014年 | 62篇 |
2013年 | 91篇 |
2012年 | 68篇 |
2011年 | 56篇 |
2010年 | 59篇 |
2009年 | 45篇 |
2008年 | 90篇 |
2007年 | 75篇 |
2006年 | 85篇 |
2005年 | 80篇 |
2004年 | 71篇 |
2003年 | 73篇 |
2002年 | 65篇 |
2001年 | 61篇 |
2000年 | 51篇 |
1999年 | 69篇 |
1998年 | 30篇 |
1997年 | 46篇 |
1996年 | 32篇 |
1995年 | 19篇 |
1994年 | 16篇 |
1993年 | 9篇 |
1992年 | 6篇 |
1991年 | 6篇 |
1990年 | 7篇 |
1989年 | 7篇 |
1988年 | 4篇 |
1987年 | 3篇 |
1986年 | 2篇 |
1985年 | 2篇 |
1984年 | 9篇 |
1983年 | 2篇 |
1982年 | 3篇 |
1981年 | 2篇 |
1980年 | 1篇 |
1979年 | 3篇 |
1978年 | 1篇 |
1976年 | 1篇 |
1973年 | 2篇 |
排序方式: 共有1615条查询结果,搜索用时 421 毫秒
61.
Sh. A. Ayupov 《Functional Analysis and Its Applications》2002,36(2):145-147
In this note we describe (up to isomorphism) the real von Neiman algebras R with Abelian skew-symmetric part
, i.e., such that xy-yx=0 for any
. 相似文献
62.
63.
We compute the Euler characteristics of the individual connectedcomponents of the intersection of two opposed big cells in thereal flag variety of type G2, verifying a conjecture of Rietsch[6]. 2000 Mathematical Subject Classification: primary 14M15; secondary20G20. 相似文献
64.
We investigate finite lattice approximations to the Wilson renormalization group in models of unconstrained spins. We discuss first the properties of the renormalization group transformation (RGT) that control the accuracy of this type of approximation and explain different methods and techniques to practically identify them. We also discuss how to determine the anomalous dimension of the field. We apply our considerations to a linear sigma model in two dimensions in the domain of attraction of the Ising fixed point using a Bell–Wilson RGT. We are able to identify optimal RGTs which allow accurate computations of quantities such as critical exponents, fixed-point couplings and eigenvectors with modest statistics. We finally discuss the advantages and limitations of this type of approach. 相似文献
65.
In this paper we obtain a formula for the average density of the distribution of complex zeros of an algebraic polynomial with random coefficients. The coefficients are assumed independent identical normally distributed random variables with mean and variance 2. The value of the average density for the case of =0 and 2=1 was obtained previously. Some limits of the distribution of the complex zeros are provided using the presented formula. 相似文献
66.
Zeng Guangxing 《中国科学A辑(英文版)》1999,42(3):272-280
For an ordered field (K,T) and an idealI of the polynomial ring
, the construction of the generalized real radical
ofI is investigated. When (K,T) satisfies some computational requirements, a method of computing
is presented.
Project supported by the National Natural Science Foundation of China (Grant No. 19661002) and the Climbing Project. 相似文献
67.
Takashi Sakamoto 《Proceedings of the American Mathematical Society》1999,127(1):205-210
For a non-unital C-algebra , let be the C-algebra obtained from by adjoining an identity. In this paper we show that
where is a locally compact Hausdorff space with .
68.
Ken Ono 《Compositio Mathematica》1999,119(1):1-11
Let D denote the fundamental discriminant of a real quadratic field, and let h(D) denote its associated class number. If p is prime, then the Cohen and Lenstra Heuristics give a probability that ph(D). If pgt;3 is prime, then subject to a mild condition, we show that
This condition holds for each 3<p<5000. 相似文献
69.
We prove that if (,D) is a positivity preserving form on L
2
(E;m), and if (u
n)n is a sequence in D() converging m-almost everywhere to u L
2
(E;m), then (u,u) lim infn (u
n
,u
n
). 相似文献
70.
K. Farahmand 《Proceedings of the American Mathematical Society》1999,127(11):3339-3344
This paper provides asymptotic estimates for the expected number of real zeros and -level crossings of a random algebraic polynomial of the form , where are independent standard normal random variables and is a constant independent of . It is shown that these asymptotic estimates are much greater than those for algebraic polynomials of the form .