全文获取类型
收费全文 | 1406篇 |
免费 | 44篇 |
国内免费 | 14篇 |
专业分类
化学 | 950篇 |
晶体学 | 15篇 |
力学 | 36篇 |
数学 | 282篇 |
物理学 | 181篇 |
出版年
2021年 | 10篇 |
2020年 | 13篇 |
2019年 | 14篇 |
2018年 | 21篇 |
2017年 | 10篇 |
2016年 | 25篇 |
2015年 | 23篇 |
2014年 | 22篇 |
2013年 | 79篇 |
2012年 | 75篇 |
2011年 | 59篇 |
2010年 | 47篇 |
2009年 | 26篇 |
2008年 | 62篇 |
2007年 | 65篇 |
2006年 | 82篇 |
2005年 | 49篇 |
2004年 | 55篇 |
2003年 | 46篇 |
2002年 | 51篇 |
2001年 | 25篇 |
2000年 | 15篇 |
1999年 | 14篇 |
1998年 | 17篇 |
1997年 | 17篇 |
1996年 | 20篇 |
1995年 | 18篇 |
1994年 | 14篇 |
1993年 | 27篇 |
1992年 | 16篇 |
1991年 | 14篇 |
1990年 | 18篇 |
1989年 | 10篇 |
1988年 | 23篇 |
1987年 | 17篇 |
1986年 | 14篇 |
1985年 | 29篇 |
1984年 | 28篇 |
1983年 | 10篇 |
1982年 | 31篇 |
1981年 | 15篇 |
1980年 | 23篇 |
1979年 | 19篇 |
1978年 | 17篇 |
1976年 | 18篇 |
1975年 | 10篇 |
1974年 | 12篇 |
1973年 | 21篇 |
1972年 | 14篇 |
1971年 | 10篇 |
排序方式: 共有1464条查询结果,搜索用时 375 毫秒
131.
G. Lunge A. Zeckendorf H. Wolpert H. Trautzsch J. Rosenthal O. Schulz W. Ohlmüller M. Müller J. B. Cohen G. Appleyard Fl Kratschmer E. Wiener Henriet W. Fossek M. Teich F. Clowes N. P. Schierbeck E. Cramer A. v. Bibra G. Defren Renk Hilger E. v. Raumer G. Gaglio Merget J. Uffelmann L. A. Nekam J. Archarow Kijanicin L. Eisenlohr Cl Fermi C. Arens H. Wegmann E. Knorr J. König und A. Bömer 《Fresenius' Journal of Analytical Chemistry》1897,36(1):329-340
Ohne Zusammenfassung 相似文献
132.
The sampling methodologies employed in Fourier Transform Infrared (FT-IR) spectroscopy tend to distort to a degree the data obtained relative to that which would be obtained via transmittance. This distortion complicates data base searching. A standard sample of polystyrene was investigated using the techniques of transmittance, attenuated total reflectance (ATR), diffuse reflectance (DRIFT) and photoacoustic spectroscopy (PAS). Several types of corrections are employed to minimize the distortions due to sampling methodologies.These corrections are evaluated with respect to four distinct search algorithms. The results obtained indicate that proper mathematical treatment of the data prior to data base searching enhances the discrimination value of a data base search. 相似文献
133.
134.
A. Tschirch H. Rosenthal G. Friedl?nder und W. Schneiter 《Fresenius' Journal of Analytical Chemistry》1929,76(7-8):312-314
Ohne Zusammenfassung 相似文献
135.
136.
137.
J. H. Bruun R. T. Leslie S. T. Schicktanz F. W. Toms C. P. Money 《Analytical and bioanalytical chemistry》1932,88(11-12):466-467
138.
A. Rosenthal 《Israel Journal of Mathematics》1987,60(1):31-38
We prove that any free ergodicZ
2-action has a strictly ergodic and topologically mixing model. 相似文献
139.
Sarah R. Dennison Leslie H.G. Morton Andrea J. Shorrocks Frederick Harris David A. Phoenix 《Colloids and surfaces. B, Biointerfaces》2009,68(2):225-230
Aurein 2.5 (GLFDIVKKVVGAFGSL-NH2) is an uncharacterised antimicrobial peptide. At an air/water interface, it exhibited strong surface activity (maximal surface pressure 25 mN m−1) and molecular areas consistent with the adoption of α-helical structure orientated either perpendicular (1.72 nm2 molecule−1) or parallel (3.6 nm2 molecule−1) to the interface. Aurein 2.5 was strongly antibacterial, exhibiting a minimum inhibitory concentration (MIC) of 30 μM against Bacillus subtilis and Escherichia coli. The peptide induced maximal surface pressure changes of 9 mN m−1 and 5 mN m−1, respectively, in monolayers mimicking membranes of these organisms whilst compression isotherm analysis of these monolayers showed ΔGMix > 0, indicating destabilisation by Aurein 2.5. These combined data suggested that toxicity of the peptide to these organisms may involve membrane invasion via the use of oblique orientated α-helical structure. The peptide induced strong, comparable maximal surface changes in monolayers of DOPG (7.5 mN m−1) and DOPE monolayers (6 mN m−1) suggesting that the membrane interactions of Aurein 2.5 were driven by amphiphilicity rather than electrostatic interaction. Based on these data, it was suggested that the differing ability of Aurein 2.5 to insert into membranes of B. subtilis and E. coli was probably related to membrane-based factors such as differences in lipid packing characteristics. The peptide was active against both sessile E. coli and Staphylococcus aureus with an MIC of 125 μM. The broad-spectrum antibacterial activity and non-specific modes of membrane action used by Aurein 2.5 suggested use as an anti-biofilm agent such as in the decontamination of medical devices. 相似文献
140.
Groups of structurally related materials, including the alkali halides, exhibit a proportionality of isothermal compressibility to formula-unit volume. The relationship has recently been explored by Glasser and by Recio et al. In this paper, we present the consequences of such proportionality on the relationships of Born-Lande? and Born-Mayer parameters to the formula-unit volume. These relationships have then been tested separately on (i) alkali (excluding cesium) halides and (ii) cesium halides. We conclude that the equations fit the NaCl-type materials satisfactorily, but less well for the CsCl-type materials, and that the Born-Mayer equation is more applicable. These results confirm the conclusion that volume is intimately linked to thermodynamic quantities, as already demonstrated by our development of volume-based thermodynamics (VBT). 相似文献