全文获取类型
收费全文 | 4758篇 |
免费 | 184篇 |
国内免费 | 179篇 |
专业分类
化学 | 4909篇 |
力学 | 93篇 |
数学 | 12篇 |
物理学 | 107篇 |
出版年
2023年 | 7篇 |
2022年 | 21篇 |
2021年 | 54篇 |
2020年 | 43篇 |
2019年 | 66篇 |
2018年 | 45篇 |
2017年 | 51篇 |
2016年 | 108篇 |
2015年 | 106篇 |
2014年 | 103篇 |
2013年 | 143篇 |
2012年 | 167篇 |
2011年 | 217篇 |
2010年 | 216篇 |
2009年 | 279篇 |
2008年 | 199篇 |
2007年 | 193篇 |
2006年 | 291篇 |
2005年 | 412篇 |
2004年 | 261篇 |
2003年 | 205篇 |
2002年 | 118篇 |
2001年 | 80篇 |
2000年 | 116篇 |
1999年 | 106篇 |
1998年 | 75篇 |
1997年 | 119篇 |
1996年 | 103篇 |
1995年 | 101篇 |
1994年 | 82篇 |
1993年 | 70篇 |
1992年 | 87篇 |
1991年 | 80篇 |
1990年 | 88篇 |
1989年 | 68篇 |
1988年 | 91篇 |
1987年 | 65篇 |
1986年 | 56篇 |
1985年 | 49篇 |
1984年 | 69篇 |
1983年 | 50篇 |
1982年 | 78篇 |
1981年 | 59篇 |
1980年 | 37篇 |
1979年 | 59篇 |
1978年 | 28篇 |
排序方式: 共有5121条查询结果,搜索用时 0 毫秒
1.
2.
Capillary Electrophoresis Chiral Separation for Enantiomeric Purity Determination of a Basic Drug in Pharmaceutical Formulations 总被引:1,自引:0,他引:1
Capillary electrophoresis using a running buffer composed of β-cyclodextrin as the chiral selector and ethanolamine mesylate at pH 9.6 is being used to monitor the stereochemical stability of a hydrophobic drug, containing two chiral centers, in two different formulated self-emulsifying drug delivery system (SEDDS) products. The separation takes place in less than 25 min. Strategies for enhancing the method reproducibility and detection sensitivity in the lower potency formulation are presented. The results demonstrating the specificity, assay precision, recovery, linearity and range achieved during the method validation experiments are presented in this paper.Presented at: CE in the Biotechnology and Pharmaceutical Industries: 7th Symposium on the Practical Applications for the Analysis of Proteins, Nucleotides and Small Molecules, Montreal, Canada, August 12–16, 2005. 相似文献
3.
V.B. Fainerman V.N. Kazakov S.V. Lylyk A.V. Makievski R. Miller 《Colloids and surfaces. A, Physicochemical and engineering aspects》2004,250(1-3):97-102
One of the essential differences in the design of bubble pressure tensiometers consists in the geometry of the measuring capillaries. To reach extremely short adsorption times of milliseconds and below, the so-called deadtime of the capillaries must be of the order of some 10 ms. In particular, for concentrated surfactant solutions, such as micellar solutions, short deadtimes are needed to minimize the initial surfactant load of the generated bubbles. A theoretical model is derived and confirmed by experiments performed for a wide range of experimental conditions, mainly in respect to variations in deadtime and bubble volume. 相似文献
4.
Becky Lavi Abraham Marmur 《Colloids and surfaces. A, Physicochemical and engineering aspects》2004,250(1-3):409-414
An equation for the kinetics of partial drop spreading is proposed. This equation was empirically derived from experimental data for the spreading kinetics of partially wetting liquids in terms of the wet area versus time. The equation has the form of an exponential power law (EPL), and transforms into the well-known power law for complete wetting, when the equilibrium contact angle approaches zero. The EPL fits very well available experimental data. To lend additional support to the validity of this generalized equation, it will be demonstrated that when it is transformed to present the dynamic contact angle (DCA), it fits very well DCA experimental data for other wetting processes, such as capillary flow and tape coating. 相似文献
5.
The content of residual monomers is one of the most important characteristics of polymer dispersions. As a result of the similar physicochemical parameters of ethyl acrylate and methyl methacrylate, it is very difficult to determine the residual monomers in acrylate dispersions obtained by emulsion polymerization of both monomers. Gas chromatography with capillary columns, however, permits separation of these monomers and their quantitative determination in acrylate dispersions. 相似文献
6.
7.
8.
9.
10.
T. A. Berger 《Journal of separation science》1989,12(2):96-100
A model for restrictor flow produces accurate predictions of flow that can be used to optimize restrictor design. The relative amplitudes of restrictor and other flows and their effect on efficiency are discussed. 相似文献