全文获取类型
收费全文 | 9781篇 |
免费 | 269篇 |
国内免费 | 33篇 |
学科分类
数理化 | 10083篇 |
出版年
2023年 | 53篇 |
2022年 | 81篇 |
2021年 | 116篇 |
2020年 | 132篇 |
2019年 | 124篇 |
2018年 | 180篇 |
2017年 | 158篇 |
2016年 | 279篇 |
2015年 | 274篇 |
2014年 | 314篇 |
2013年 | 566篇 |
2012年 | 606篇 |
2011年 | 656篇 |
2010年 | 441篇 |
2009年 | 365篇 |
2008年 | 530篇 |
2007年 | 550篇 |
2006年 | 505篇 |
2005年 | 456篇 |
2004年 | 400篇 |
2003年 | 291篇 |
2002年 | 290篇 |
2001年 | 158篇 |
2000年 | 171篇 |
1999年 | 121篇 |
1998年 | 112篇 |
1997年 | 83篇 |
1996年 | 113篇 |
1995年 | 70篇 |
1994年 | 86篇 |
1993年 | 74篇 |
1992年 | 82篇 |
1991年 | 77篇 |
1990年 | 70篇 |
1989年 | 78篇 |
1988年 | 56篇 |
1987年 | 55篇 |
1986年 | 59篇 |
1985年 | 64篇 |
1984年 | 60篇 |
1983年 | 45篇 |
1982年 | 49篇 |
1981年 | 62篇 |
1980年 | 39篇 |
1979年 | 57篇 |
1978年 | 51篇 |
1977年 | 39篇 |
1976年 | 55篇 |
1973年 | 45篇 |
1958年 | 41篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
Lubomír Kubáček 《Applications of Mathematics》2006,51(6):565-582
Some remarks to problems of point and interval estimation, testing and problems of outliers are presented in the case of multivariate
regression model.
This work was supported by the Council of Czech Government J14/98:153100011. 相似文献
3.
4.
Sándor G?r?g 《Analytical sciences》2004,20(5):767-782
The development during the last 15 years and the state-of-the-art in the analysis of bulk steroid hormone drugs and hormone-like structures and pharmaceutical formulations made thereof are summarized. Other steroids (sterols, bile acids, cardiac glycosides, vitamins D) as well as biological-clinical aspects and pharmacokinetic and metabolic studies are excluded from this review. The state-of-the-art is summarized based on comparisons of monographs in the latest editions of the European Pharmacopoeia, United States Pharmacopoeia and the Japanese Pharmacopoeia. This is followed by sections dealing with new developments in the methodology for the fields of spectroscopic and spectrophotometric, chromatographic, electrophoretic and hyphenated techniques as well electroanalytical methods. The review is terminated by two problem-oriented sections: examples on impurity and degradation profiling as well as enantiomeric analysis. 相似文献
5.
Bogdan Ka
mierczak Kazimierz Piechr 《Mathematical Methods in the Applied Sciences》2004,27(11):1317-1345
In this paper we study travelling wave solutions to a system of four non‐linear partial differential equations, which arise in a tissue interaction model for skin morphogenesis. Under the ‘small‐stress’ assumption we prove the existence and uniqueness (up to a translation) of solutions with the dermis and epidermis cell densities being positive, which are a perturbation of a uniform epidermal cell density. We discuss the problem of the minimal wave‐speed. Copyright © 2004 John Wiley & Sons, Ltd. 相似文献
6.
Pál Sohár Gábor Bernáth Géza Stájer Angela E. Szabo 《Magnetic resonance in chemistry : MRC》1989,27(9):872-876
Pentacyclic isoxazolines were obtained by the cycloaddition of benzonitrile oxide to norbornene-azetidinone-fused 3,1-oxazines. The constitutions of two of the isomers obtained, and the configurations and conformations of all products, were determined by means of 1H and 13C NMR spectroscopy and DNOE experiments. 相似文献
7.
Bubble pressure points of ethanol–1,1,1,2,3,3,3-heptafluoropropane (HFC-227ea refrigerant) mixtures from the third Industrial Fluid Properties Simulation Challenge are computed using publicly available molecular simulation software. Several published force fields are compared against the known answers provided in the contest guidelines and the best force fields are used to make predictions for the unknown results. 相似文献
8.
We extend the previously found accelerated Kerr-Schild metrics for Einstein-Maxwell-null dust and Einstein-Born-Infeld-null dust equations to the cases including the cosmological constant. This way we obtain the generalization of the charged de Sitter metrics in static space-times. We also give a generalization of the zero acceleration limit of our previous Einstein-Maxwell and Einstein-Born-Infeld solutions. 相似文献
9.
The rate-dependent effects in metallic ferromagnetic materials with magnetization processes attributed to domain-walls motion were studied. The experimental method for eddy-current relaxation time determination was proposed. Some discrepancies between the data and theoretical predictions were observed and discussed. The origin of these discrepancies is accounted for by the decrease of viscous-type relaxation process as the rate of change of averaged magnetization is approaching zero. 相似文献
10.
In this paper we extend a result of Semrl stating that every 2-local automorphism of the full operator algebra on a separable infinite dimensional Hilbert space is an automorphism. In fact, besides separable Hilbert spaces, we obtain the same conclusion for the much larger class of Banach spaces with Schauder bases. The proof rests on an analogous statement concerning the 2-local automorphisms of matrix algebras for which we present a short proof. The need to get such a proof was formulated in Semrl's paper.