全文获取类型
收费全文 | 12349篇 |
免费 | 333篇 |
国内免费 | 6篇 |
专业分类
化学 | 6884篇 |
晶体学 | 136篇 |
力学 | 200篇 |
数学 | 2266篇 |
物理学 | 3202篇 |
出版年
2022年 | 121篇 |
2021年 | 188篇 |
2020年 | 182篇 |
2019年 | 157篇 |
2018年 | 232篇 |
2017年 | 251篇 |
2016年 | 517篇 |
2015年 | 373篇 |
2014年 | 445篇 |
2013年 | 934篇 |
2012年 | 610篇 |
2011年 | 715篇 |
2010年 | 474篇 |
2009年 | 398篇 |
2008年 | 420篇 |
2007年 | 375篇 |
2006年 | 296篇 |
2005年 | 238篇 |
2004年 | 213篇 |
2003年 | 205篇 |
2002年 | 233篇 |
2001年 | 157篇 |
2000年 | 159篇 |
1999年 | 161篇 |
1998年 | 153篇 |
1997年 | 139篇 |
1996年 | 146篇 |
1995年 | 140篇 |
1994年 | 120篇 |
1993年 | 138篇 |
1992年 | 132篇 |
1991年 | 123篇 |
1990年 | 124篇 |
1989年 | 121篇 |
1988年 | 112篇 |
1987年 | 135篇 |
1986年 | 103篇 |
1985年 | 143篇 |
1984年 | 149篇 |
1983年 | 138篇 |
1982年 | 126篇 |
1981年 | 130篇 |
1980年 | 127篇 |
1979年 | 137篇 |
1978年 | 127篇 |
1977年 | 121篇 |
1976年 | 117篇 |
1975年 | 104篇 |
1974年 | 107篇 |
1973年 | 104篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
Chromatographia - A theoretical model is used to predict retention times of divalent metal cations in single-column ion chromatography using one or more ligands in the eluent. Stability constants... 相似文献
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.
A computer construction of the Monster is used to prove thatPSL(2, 59) is a subgroup of the Monster. 相似文献
4.
Harnack inequality for some classes of Markov processes 总被引:3,自引:0,他引:3
In this paper we establish a Harnack inequality for nonnegative harmonic functions of some classes of Markov processes with jumps.
Mathematics Subject Classification (2000): Primary 60J45, 60J75, Secondary 60J25.This work was completed while the authors were in the Research in Pairs program at the Mathematisches Forschungsinstitut Oberwolfach. We thank the Institute for the hospitality.The research of this author is supported in part by NSF Grant DMS-9803240.The research of this author is supported in part by MZT grant 0037107 of the Republic of Croatia. 相似文献
5.
6.
We study condensation of ethanol-hexanol vapour by numerical solution of kinetic equations. The number of droplets formed
in unit volume is computed within self-consistent classical model. It is shown that formation of ethanol-rich droplets prevails
at the initial stage of nucleation process, but in the stationary state formation of droplets near the saddle point (on cluster
formation energy surface) plays the dominant role.
Presented at the 6th Joint Seminar “Development of Materials Science in Research and Education”, Karlštejn, Czech Republic,
17–19 September 1996.
This work was supported by Grant No. A1010615 of the Grant Agency of the Academy of Sciences of the Czech Republic. 相似文献
7.
The purpose of this paper is to give the Reid ``Roundabout Theorem' for quadratic functionals with general boundary conditions.
In particular, we describe the so-called coupled point and regularity condition introduced in [16] in terms of Riccati equation
solutions.
Accepted 27 February 1996 相似文献
8.
Botjan Japelj Simon Re
nik Petra ebaek Branko Stanovnik Jurij Svete 《Journal of heterocyclic chemistry》2005,42(6):1167-1173
A series of alkyl l‐heteroaryl‐1H‐1,2,3‐triazole‐4‐carboxylates 6a‐u were synthesised in four steps from methyl (Z)‐2‐benzyloxycarbonylarmino‐3‐(dimethylamino)prop‐2‐enoate ( 1 ) and heterocyclic amines 2a‐s. Triazoles 6a‐o were tested against antimycobacterial activity. For the most active compound, n‐pentyl 1‐(6‐phenylpyridazin‐3‐yl)‐1H‐1,2,3‐triazole‐4‐carboxylate ( 6n ), minimum inhibitory concentration 3.13 μg/ml was determined. 相似文献
9.
On‐line coupling of LC and ICP‐MS has been used for fractionation and detection of species of Cu, Fe, I, Se and Zn in human serum. It has been shown that anion exchange chromatography provided better separation capability (both intra‐ and inter‐element) than size‐exclusion chromatography. The mobile phases for ion exchange chromatography consisted of Tris–HNO3 buffer and ammonium salt (nitrate, acetate or formate). Formate was found to be the best mobile phase counter ion, enabling good chromatographic separation, and is acceptable for mass spectrometry too. The quantitative evaluation of element concentrations adhering to individual fractions was performed by the peak area normalization method. The repeatability of results ranged from 3 to 15% (depending on the element concentration level) and represented the main part of the result uncertainty. The accuracy of Cu and Zn fraction determinations was confirmed by comparison with the isotope dilution technique. Copyright © 2006 John Wiley & Sons, Ltd. 相似文献
10.
The complete set of self-consistent parameters of nominally undoped LiNbO3 crystals of congruent composition that describe the electro-optic, piezoelectric, elasto-optic, elastic, and dielectric response
has been determined by numerically evaluating available measurements. The parameters were determined at room temperature and
consist of the low-frequency clamped dielectric constants εS
ij, elastic stiffness constants at constant electric field CE
ijkl, piezoelectric stress coefficients eijk, elasto-optic constants at constant electric field pE
ijkl, and clamped electro-optic coefficients rS
ijk. It is shown that the complete set is required for calculating the effective electro-optic coefficients and dielectric constants
in photorefractive applications of LiNbO3.
Received: 4 January 2002 / Revised version: 1 February 2002 / Published online: 14 March 2002 相似文献