全文获取类型
收费全文 | 2706篇 |
免费 | 99篇 |
国内免费 | 247篇 |
专业分类
化学 | 53篇 |
力学 | 63篇 |
综合类 | 27篇 |
数学 | 2645篇 |
物理学 | 264篇 |
出版年
2024年 | 3篇 |
2023年 | 36篇 |
2022年 | 33篇 |
2021年 | 37篇 |
2020年 | 88篇 |
2019年 | 79篇 |
2018年 | 69篇 |
2017年 | 71篇 |
2016年 | 82篇 |
2015年 | 54篇 |
2014年 | 103篇 |
2013年 | 259篇 |
2012年 | 69篇 |
2011年 | 149篇 |
2010年 | 128篇 |
2009年 | 175篇 |
2008年 | 194篇 |
2007年 | 179篇 |
2006年 | 148篇 |
2005年 | 136篇 |
2004年 | 99篇 |
2003年 | 130篇 |
2002年 | 108篇 |
2001年 | 91篇 |
2000年 | 97篇 |
1999年 | 90篇 |
1998年 | 74篇 |
1997年 | 76篇 |
1996年 | 52篇 |
1995年 | 26篇 |
1994年 | 17篇 |
1993年 | 10篇 |
1992年 | 6篇 |
1991年 | 6篇 |
1990年 | 8篇 |
1989年 | 13篇 |
1988年 | 4篇 |
1987年 | 11篇 |
1986年 | 5篇 |
1985年 | 9篇 |
1984年 | 5篇 |
1983年 | 4篇 |
1982年 | 3篇 |
1981年 | 4篇 |
1980年 | 2篇 |
1978年 | 2篇 |
1977年 | 1篇 |
1975年 | 2篇 |
1974年 | 2篇 |
1936年 | 2篇 |
排序方式: 共有3052条查询结果,搜索用时 500 毫秒
21.
Linear complexity and linear complexity profile are important characteristics of a sequence for applications in cryptography
and Monte-Carlo methods.
The nonlinear congruential method is an attractive alternative to the classical linear congruential method for pseudorandom
number generation.
Recently, a weak lower bound on the linear complexity profile of a general nonlinear congruential pseudorandom number generator
was proven by Gutierrez, Shparlinski and the first author. For most nonlinear generators a much stronger lower bound is expected.
Here, we obtain a much stronger lower bound on the linear complexity profile of nonlinear congruential pseudorandom number
generators with Dickson polynomials. 相似文献
22.
《Journal of Computational and Applied Mathematics》2005,174(2):383-397
This paper is devoted to the testing and comparison of numerical solutions obtained from higher-order accurate finite difference schemes for the two-dimensional Burgers' equation having moderate to severe internal gradients. The fourth-order accurate two-point compact scheme, and the fourth-order accurate Du Fort Frankel scheme are derived. The numerical stability and convergence are presented. The cases of shock waves of severe gradient are solved and checked with the fourth-order accurate Du Fort Frankel scheme solutions. The present study shows that the fourth-order two-point compact scheme is highly stable and efficient in comparison with the fourth-order accurate Du Fort Frankel scheme. 相似文献
23.
24.
Hirofumi Tsumura. 《Mathematics of Computation》2004,73(245):251-258
In this paper, we give some evaluation formulas for Tornheim's type of alternating series by an elementary and combinatorial calculation of the uniformly convergent series. Indeed, we list several formulas for them by means of Riemann's zeta values at positive integers.
25.
D. Barrios Rolanía G. Lpez Lagomasino E. B. Saff 《Journal of Approximation Theory》2003,124(2):263-281
Using a convergence theorem for Fourier–Padé approximants constructed from orthogonal polynomials on the unit circle, we prove an analogue of Hadamard's theorem for determining the radius of m-meromorphy of a function analytic on the unit disk and apply this to the location of poles of the reciprocal of Szeg
functions. 相似文献
26.
Alvaro P. Raposo Hans J. Weber David E. Alvarez-Castillo Mariana Kirchbach 《Central European Journal of Physics》2007,5(3):253-284
We briefly review the five possible real polynomial solutions of hypergeometric differential equations. Three of them are
the well known classical orthogonal polynomials, but the other two are different with respect to their orthogonality properties.
We then focus on the family of polynomials which exhibits a finite orthogonality. This family, to be referred to as the Romanovski
polynomials, is required in exact solutions of several physics problems ranging from quantum mechanics and quark physics to
random matrix theory. It appears timely to draw attention to it by the present study. Our survey also includes several new
observations on the orthogonality properties of the Romanovski polynomials and new developments from their Rodrigues formula. 相似文献
27.
LIU Zhongkui 《数学年刊B辑(英文版)》2004,25(1):129-138
Let (S,≤) be an ordered set. Recall that (S,≤) is artinian if every strictly decreasingsequence of elements of S is ?nite, and that (S,≤) is narrow if every subset of pairwiseorder-incomparable elements of S is ?nite. Let S be a commutative monoid. Unl… 相似文献
28.
根据广义Laguerre多项式的数学性质,导出了较为简单的三维各向同性谐振子径向矩阵元的普遍公式,并在这基础上计算了一些重要特殊情形的径向矩阵元: 矢径r整数次幂的平均值,电偶极跃迁矩阵元和电四极跃迁矩阵元.
关键词:
三维各向同性谐振子
径向矩阵元
广义Laguerre多项式
偶极跃迁
四极跃迁 相似文献
29.
G. Mastroianni 《Numerical Algorithms》1995,10(1):113-126
The author gives some upper and lower bounds for the generalized Christoffel functions related to a Ditzian-Totik generalized weight. As an application, an error estimate of Gauss quadrature formula inL
1-weighted norm is derived.Dedicated to Prof. Luigi Gatteschi on the occasion of his 70th birthdayWork sponsored by MURST 40%. 相似文献
30.
Rajesh Pereira 《Journal of Mathematical Analysis and Applications》2003,285(1):336-348
In 1959, Davis introduced the concept of a differentiator of an operator on a finite-dimensional Hilbert space. We prove that every such operator possesses a differentiator. We also use the theory of differentiators to solve several problems in the geometry of polynomials. For instance, we answer in the affirmative a twenty year old unsolved conjecture of Schoenberg, a related conjecture of Katsoprinakis and a fifty year old unsolved conjecture of De Bruijn and Springer. 相似文献