全文获取类型
收费全文 | 1464篇 |
免费 | 170篇 |
国内免费 | 150篇 |
专业分类
化学 | 342篇 |
晶体学 | 9篇 |
力学 | 106篇 |
综合类 | 29篇 |
数学 | 947篇 |
物理学 | 351篇 |
出版年
2023年 | 13篇 |
2022年 | 37篇 |
2021年 | 39篇 |
2020年 | 34篇 |
2019年 | 34篇 |
2018年 | 30篇 |
2017年 | 48篇 |
2016年 | 53篇 |
2015年 | 30篇 |
2014年 | 62篇 |
2013年 | 94篇 |
2012年 | 53篇 |
2011年 | 74篇 |
2010年 | 77篇 |
2009年 | 71篇 |
2008年 | 100篇 |
2007年 | 94篇 |
2006年 | 89篇 |
2005年 | 63篇 |
2004年 | 67篇 |
2003年 | 80篇 |
2002年 | 69篇 |
2001年 | 59篇 |
2000年 | 50篇 |
1999年 | 56篇 |
1998年 | 53篇 |
1997年 | 28篇 |
1996年 | 44篇 |
1995年 | 26篇 |
1994年 | 13篇 |
1993年 | 19篇 |
1992年 | 12篇 |
1991年 | 15篇 |
1990年 | 8篇 |
1989年 | 13篇 |
1988年 | 6篇 |
1987年 | 4篇 |
1986年 | 6篇 |
1985年 | 5篇 |
1984年 | 8篇 |
1983年 | 6篇 |
1982年 | 12篇 |
1980年 | 4篇 |
1979年 | 5篇 |
1978年 | 2篇 |
1977年 | 5篇 |
1976年 | 2篇 |
1974年 | 3篇 |
1973年 | 3篇 |
1957年 | 2篇 |
排序方式: 共有1784条查询结果,搜索用时 31 毫秒
1.
WANG Zhong HONG Haitao XIAO Hai SUN Changku MENG Yan YE Shenghua 《Chinese Journal of Lasers》1997,6(5):435-440
1.IntroductionAbsolutedistancemeasurementisfarfromanewtopic.However,itisstillafieldstimulatinggreatinterestsnowadaysduetoitSimportantroleinmanufacturingandassembly['J.SincethegreatsuccessachievedbyMichelsonandBenoitwhentheyfirstdevelopedaninterferometertodeterminethestandardmeterintermsofthemonochromaticredcadmiumline,theopticinterferometerhasbeenprovedtobeoneofthemostpreciseandefficientwayindisplacementmeasurementbecauseofitshighdiscriminationandsimplestructure.However,thetraditionalinterfe… 相似文献
2.
LIU Jixue ZHANG Sanguo & CHEN Xiru Department of Statistics Finance University of Science Technology of China Hefei China Department of Mathematics Graduate School of Chinese Academy of Sciences Beijing China 《中国科学A辑(英文版)》2006,49(6):752-769
This paper studies the linear EV model when replicate observations are made only on independent variables. We construct the estimates of regression coefficients and prove the consistency and asymptotic normality under some proper conditions. Results obtained reveal the difference between the case where the independent and dependent variables are observed repeatedly and simultaneously and the case studied in this article. 相似文献
3.
Harel and Puri (1989, J. Multivariate Anal. 29) studied the asymptotic behavior of the U-statistic and the one-sample rank order statistic for nonstationary absolutely regular processes. In this note, we present some applications of these results for Markov processes as well as ARMA processes. 相似文献
4.
Lihong Wang 《Annals of the Institute of Statistical Mathematics》2004,56(2):251-264
The purpose of this paper is to investigate the asymptotic properties of the least squares estimates (L
2-estimates) and the least absolute deviation estimates (L
1-estimates) of the parameters of a nonlinear regression model subject to a set of equality and inequality restrictions, which
has a long-range dependent stationary process as its stochastic errors. Then we will compare the asymptotic relative efficiencies
of the above estimators. 相似文献
5.
6.
A stochastic approximation algorithm for estimating multichannel coefficients is proposed, and the estimate is proved to converge to the true parameters a.s. up-to a constant scaling factor. The estimate is updated after receiving each new observation, so the output data need not be collected in advance. The input signal is allowed to be dependent and the observation is allowed to be corrupted by noise, but no noise statistics are used in the estimation algorithm. 相似文献
7.
We investigate some topological properties of a normal functorH introduced earlier by Radul which is some functorial compactification of the Hartman-Mycielski construction HM. We prove
that the pair (H X, HMY) is homeomorphic to the pair (Q, σ) for each nondegenerated metrizable compactumX and each denseσ-compact subsetY. 相似文献
8.
本文讨论由L2深度修正得到的L2深度相应的样本深度的性质,得到了样本深度的相合性和渐近正态性,并证明了它在任意紧集上的一致相合性.最后,基于上述性质简要讨论了样本深度等高的一些性质. 相似文献
9.
We introduce the time-consistency concept that is inspired by the so-called “principle of optimality” of dynamic programming
and demonstrate – via an example – that the conditional value-at-risk (CVaR) need not be time-consistent in a multi-stage
case. Then, we give the formulation of the target-percentile risk measure which is time-consistent and hence more suitable
in the multi-stage investment context. Finally, we also generalize the value-at-risk and CVaR to multi-stage risk measures
based on the theory and structure of the target-percentile risk measure. 相似文献
10.
对Hajek-Renyi不等式进行了推广,利用推广的不等式给出了随机变量序列绝对平均意义下的强大数定律的一个条件. 相似文献