全文获取类型
收费全文 | 7360篇 |
免费 | 287篇 |
国内免费 | 369篇 |
专业分类
化学 | 1599篇 |
晶体学 | 4篇 |
力学 | 286篇 |
综合类 | 61篇 |
数学 | 4830篇 |
物理学 | 1236篇 |
出版年
2024年 | 7篇 |
2023年 | 76篇 |
2022年 | 150篇 |
2021年 | 168篇 |
2020年 | 125篇 |
2019年 | 157篇 |
2018年 | 127篇 |
2017年 | 201篇 |
2016年 | 209篇 |
2015年 | 148篇 |
2014年 | 305篇 |
2013年 | 623篇 |
2012年 | 366篇 |
2011年 | 387篇 |
2010年 | 364篇 |
2009年 | 504篇 |
2008年 | 497篇 |
2007年 | 503篇 |
2006年 | 365篇 |
2005年 | 278篇 |
2004年 | 286篇 |
2003年 | 216篇 |
2002年 | 206篇 |
2001年 | 147篇 |
2000年 | 134篇 |
1999年 | 138篇 |
1998年 | 151篇 |
1997年 | 117篇 |
1996年 | 140篇 |
1995年 | 105篇 |
1994年 | 124篇 |
1993年 | 84篇 |
1992年 | 86篇 |
1991年 | 59篇 |
1990年 | 46篇 |
1989年 | 36篇 |
1988年 | 31篇 |
1987年 | 27篇 |
1986年 | 38篇 |
1985年 | 47篇 |
1984年 | 45篇 |
1983年 | 18篇 |
1982年 | 45篇 |
1981年 | 21篇 |
1980年 | 27篇 |
1979年 | 30篇 |
1978年 | 19篇 |
1977年 | 13篇 |
1976年 | 9篇 |
1973年 | 5篇 |
排序方式: 共有8016条查询结果,搜索用时 15 毫秒
41.
Testing goodness of fit for the distribution of errors in multivariate linear models 总被引:2,自引:0,他引:2
M.D. Jimnez Gamero J. Muoz García R. Pino Mejías 《Journal of multivariate analysis》2005,95(2):301-322
In this paper, to test goodness of fit to any fixed distribution of errors in multivariate linear models, we consider a weighted integral of the squared modulus of the difference between the empirical characteristic function of the residuals and the characteristic function under the null hypothesis. We study the limiting behaviour of this test statistic under the null hypothesis and under alternatives. In the asymptotics, the rank of the design matrix is allowed to grow with the sample size. 相似文献
42.
The classes ofL
1-matrices,L
2-matrices,L
3-matrices andW-matrices are introduced to study solvability of a linear complementarity problem via solving a linear program. Three sufficient
conditions are presented to guarantee that a linear complementarity problem is solvable via a linear program. The new sufficient
conditions are weaker than the ones introduced by Mangasarian. This fact is also illustrated by an example.
Partially supported by NSFC.
This author is also with College of Business Administration of Human University as a Lotus chair professor. 相似文献
43.
半参数回归模型中小波估计的随机加权逼近速度 总被引:10,自引:1,他引:9
把小波光滑方法和随机加权方法结合在一起,获得了半参数回归模型中参数分量的小波估计的随机加权逼近速度为σ(n^-1/2)。因此,从大样本意义上说,小波光滑方法和随机加权方法对半参数回归模型是可用的。 相似文献
44.
A flow model in combination with a statistical-dynamical turbulence generator and a linearised Euler time-domain model for sound waves were used to simulate the effect of screen-induced turbulence on the noise level in the acoustical shadow of a screen in wind. Instead of simulating a great number of different frozen turbulence realisations, the concept of transient turbulence was successfully tested and applied. This concept is adequate to the time-domain model and reduces the computational demands. Several two-dimensional simulations allowed to isolate the individual effects of wind and screen on the propagation of 500 Hz sound waves over a 4-m high noise barrier. At a distance of 250 m from the source (240 m behind the screen) the sheltering effect of the screen and the refraction effect of the wind are in the order of 6 and 4 dB, respectively. The screen-induced turbulence leads to fluctuations in the noise level with a standard deviation of 1.2 dB and a maximum amplitude of 3 dB. However, the time averaged effect turned out to be in the order of merely 0.2 dB. The effect of the screen-induced turbulence on the average noise level behind the screen is therefore negligible. 相似文献
45.
利用集值映射不动点定理及最优化问题与变分不等式的关系给出线性G^↑ateaux可微的锥凸映射的广义有效点的一个存在性定理。 相似文献
46.
Efficiencies of the maximum pseudolikelihood estimator and a number of related estimators for the case-cohort sampling design in the proportional hazards regression model are studied. The asymptotic information and lower bound for estimating the parametric regression parameter are calculated based on the effective score, which is obtained by determining the component of the parametric score orthogonal to the space generated by the infinite-dimensional nuisance parameter. The asymptotic distributions of the maximum pseudolikelihood and related estimators in an i.i.d. setting show that these estimators do not achieve the computed asymptotic lower bound. Simple guidelines are provided to determine in which instances such estimators are close enough to efficient for practical purposes. 相似文献
47.
This paper considers the estimation problem for a trigonometric regression model with the noise specified by the Ornstein–Uhlenbeck
process with unknown parameter. We propose a sequential procedure which ensures a prescribed mean square precision uniformly
in the nuisance parameter. The asymptotic behaviour of the procedure duration mean has been studied.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
48.
THE SCHWARZIAN DERIVATIVE IN SEVERAL COMPLEX VARIABLES(II) 总被引:1,自引:0,他引:1
THESCHWARZIANDERIVATIVEINSEVERALCOMPLEXVARIABLES(II)GONGSHENGYUQIHUANGZHENGXUEANManuscriptreceivedAugust30,1996.De... 相似文献
49.
50.
Miguel A. Arcones 《Annals of the Institute of Statistical Mathematics》1998,50(1):87-117
We consider exact weak and strong Bahadur-Kiefer representations of the least absolute deviation estimator for the linear regression model. The precise behavior of these representations is obtained under minimal conditions. 相似文献