全文获取类型
收费全文 | 1355篇 |
免费 | 94篇 |
国内免费 | 86篇 |
专业分类
化学 | 174篇 |
力学 | 156篇 |
综合类 | 30篇 |
数学 | 791篇 |
物理学 | 384篇 |
出版年
2023年 | 22篇 |
2022年 | 17篇 |
2021年 | 21篇 |
2020年 | 27篇 |
2019年 | 30篇 |
2018年 | 23篇 |
2017年 | 34篇 |
2016年 | 32篇 |
2015年 | 32篇 |
2014年 | 60篇 |
2013年 | 76篇 |
2012年 | 74篇 |
2011年 | 89篇 |
2010年 | 49篇 |
2009年 | 94篇 |
2008年 | 82篇 |
2007年 | 87篇 |
2006年 | 87篇 |
2005年 | 61篇 |
2004年 | 63篇 |
2003年 | 47篇 |
2002年 | 44篇 |
2001年 | 48篇 |
2000年 | 42篇 |
1999年 | 41篇 |
1998年 | 29篇 |
1997年 | 37篇 |
1996年 | 29篇 |
1995年 | 21篇 |
1994年 | 15篇 |
1993年 | 6篇 |
1992年 | 8篇 |
1991年 | 7篇 |
1990年 | 10篇 |
1989年 | 7篇 |
1988年 | 11篇 |
1987年 | 8篇 |
1986年 | 8篇 |
1985年 | 5篇 |
1984年 | 8篇 |
1983年 | 3篇 |
1982年 | 7篇 |
1981年 | 3篇 |
1980年 | 5篇 |
1979年 | 5篇 |
1978年 | 3篇 |
1977年 | 3篇 |
1976年 | 4篇 |
1973年 | 2篇 |
1969年 | 3篇 |
排序方式: 共有1535条查询结果,搜索用时 78 毫秒
11.
12.
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
13.
In this research, we investigate stopping rules for software testing and propose two stopping rules from the aspect of software reliability testing based on the impartial reliability model. The impartial reliability difference (IRD-MP) rule considers the difference between the impartial transition-probability reliabilities estimated for both software developer and consumers at their predetermined prior information levels. The empirical–impartial reliability difference (EIRD-MP) rule suggests stopping a software test when the computed empirical transition reliability is tending to its estimated impartial transition reliability. To insure the high-standard requirement for safety-critical software, both rules take the maximum probability (MP) of untested paths into account. 相似文献
14.
The quantum action (dynamical) principle is exploited to investigate the nature and origin of the Faddeev–Popov (FP) factor in gauge theories without recourse to path integrals. Gauge invariant as well as gauge non-invariant interactions are considered to show that the FP factor needs to be modified in more general cases and expressions for these modifications are derived. In particular we show that a gauge invariant theory does not necessarily imply the familiar FP factor for proper quantization.
PACS numbers: 11.15.-q; 12.10.-g; 12.15.-y; 12.38.-t 相似文献
15.
We consider a two-dimensional Coulomb gas of positive and negative pointlike unit charges interacting via a logarithmic potential. The density (rather than the charge) correlation functions are studied. In the bulk, the form-factor theory of an equivalent sine-Gordon model is used to determine the density correlation length. At the surface of a rectilinear plain wall, the universality of the asymptotic behavior of the density correlations is suggested. A scaling analysis implies a local form of the compressibility sum rule near a hard wall. A symmetry of the Coulomb system with respect to the Möbius conformal transformation, which induces a gravitational source acting on the particle density, is established. Among the consequences, a universal term of the finite-size expansion of the grand potential is derived exactly for a disk geometry of the confining domain. 相似文献
16.
1引言 2006年3月 高等学校计算数学学报 设f(x)为卜1,1}上的连续函数,则以第二类Chebyshev多项式认(x)(Un(eoso)= 烈共坐)的全部零点{ 乙工工1口 式为 其中 k x无=Cos了一下丁7r 了L十1 犷_,为插值结点组的了的Gr如wald插值多项 G。(,,x)=艺了(x、)‘孟(x), n. 11 一一 k 相似文献
17.
Aliasing effects are investigated for spherical random fields sampled on a finite grid. Using the spherical harmonics expansion, it is shown that for a band-limited spherical random field its trend and spectrum can be uniquely reconstructed from the sampled field if the sampling points are judiciously designed. Analytical expressions are also obtained for aliasing errors in the trend and the spectrum when the field is not band-limited. 相似文献
18.
Fabio Schoen 《Journal of Global Optimization》1994,4(1):17-35
In this paper a new algorithm is proposed for global optimization problems. The main idea is that of modifying a standard clustering approach by sequentially sampling the objective function while adaptively deciding an appropriate sample size. Theoretical as well as computational results are presented. 相似文献
19.
A new numerical method called linearized and rational approximation method is presented to solve non‐linear evolution equations. The utility of the method is demonstrated for the case of differentiation of functions involving steep gradients. The solution of Burgers' equation is presented to illustrate the effectiveness of the technique for the solution of non‐linear evolution equations exhibiting nearly discontinuous solutions. Copyright © 2004 John Wiley & Sons, Ltd. 相似文献
20.