全文获取类型
收费全文 | 1474篇 |
免费 | 23篇 |
国内免费 | 2篇 |
专业分类
化学 | 852篇 |
晶体学 | 14篇 |
力学 | 19篇 |
数学 | 183篇 |
物理学 | 431篇 |
出版年
2016年 | 18篇 |
2015年 | 16篇 |
2014年 | 19篇 |
2013年 | 62篇 |
2012年 | 37篇 |
2011年 | 50篇 |
2010年 | 37篇 |
2009年 | 24篇 |
2008年 | 48篇 |
2007年 | 44篇 |
2006年 | 53篇 |
2005年 | 42篇 |
2004年 | 35篇 |
2003年 | 27篇 |
2002年 | 24篇 |
2001年 | 26篇 |
2000年 | 32篇 |
1999年 | 21篇 |
1998年 | 20篇 |
1997年 | 14篇 |
1996年 | 19篇 |
1995年 | 21篇 |
1994年 | 35篇 |
1993年 | 16篇 |
1992年 | 17篇 |
1991年 | 16篇 |
1990年 | 18篇 |
1988年 | 14篇 |
1987年 | 13篇 |
1986年 | 15篇 |
1985年 | 19篇 |
1984年 | 24篇 |
1983年 | 19篇 |
1982年 | 17篇 |
1981年 | 18篇 |
1980年 | 21篇 |
1979年 | 14篇 |
1978年 | 25篇 |
1977年 | 19篇 |
1976年 | 19篇 |
1975年 | 14篇 |
1974年 | 13篇 |
1973年 | 15篇 |
1972年 | 15篇 |
1970年 | 13篇 |
1969年 | 14篇 |
1968年 | 40篇 |
1967年 | 20篇 |
1935年 | 12篇 |
1901年 | 16篇 |
排序方式: 共有1499条查询结果,搜索用时 15 毫秒
91.
L. W. Winkler 《Fresenius' Journal of Analytical Chemistry》1926,69(1-2):76-84
Ohne Zusammenfassung 相似文献
92.
Clemens Winkler 《Fresenius' Journal of Analytical Chemistry》1889,28(1):269-289
Ohne Zusammenfassung 相似文献
93.
H. D. Richmond R. C. Frederick R. V. Stanford L. W. Winkler und S. M. Naudé 《Fresenius' Journal of Analytical Chemistry》1928,73(12):461-462
Ohne Zusammenfassung 相似文献
94.
Andr Studer Xiaojun Han Fritz K. Winkler Louis X. Tiefenauer 《Colloids and surfaces. B, Biointerfaces》2009,73(2):325-331
Free-standing lipid bilayers are formed in regularly arranged nanopores of 200, 400 and 800 nm in a 300 nm thin hydrophobic silicon nitride membrane separating two fluid compartments. The extraordinary stability of the lipid bilayers allows us to monitor channel formation of the model peptide melittin and α-hemolysin from Staphylococcus aureus using electrochemical impedance spectroscopy and chronoamperometry. We observed that melittin channel formation is voltage-dependent and transient, whereas transmembrane heptameric α-hemolysin channels in nano-BLMs persist for hours. The onset of α-hemolysin-mediated conduction depends on the applied protein concentration and strongly on the diameter of the nanopores. Heptameric channel formation from adsorbed α-hemolysin monomers needs more time in bilayers suspended in 200 nm pores compared to bilayers in pores of 400 and 800 nm diameters. Diffusion of sodium ions across α-hemolysin channels present in a sufficiently high number in the bilayers was quantitatively and specifically determined using ion selective electrodes. The results demonstrate that relatively small variations of nano-dimensions have a tremendous effect on observable dynamic biomolecular processes. Such nanopore chips are potentially useful as supports for stable lipid bilayers to establish functional assays of membrane proteins needed in basic research and drug discovery. 相似文献
95.
96.
Clemens Winkler 《Fresenius' Journal of Analytical Chemistry》1879,18(1):259
Ohne Zusammenfassung 相似文献
97.
98.
99.
100.
Rainer Cremer Mirjam Witthaut Dieter Neuschütz Cyril Trappe Martin Laurenzis Olaf Winkler Heinrich Kurz 《Mikrochimica acta》2000,133(1-4):299-302
Cu3N films for optical data storage were deposited on Si(100) wafers and 0.6 mm thick polycarbonate DVD base material discs at
a temperature of 50 °C by reactive magnetron sputtering. A copper target was sputtered in rf mode in a nitrogen plasma. For
basic investigations concerning the composition and structure of Cu3N, Si wafers were used as substrate material. To study the suitability of Cu3N as an optical data storage medium under technical conditions, Cu3N/Al bilayers were deposited on polycarbonate discs. The composition and structure of the films were investigated by X-ray
photoelectron spectroscopy (XPS) and X-ray diffraction (XRD).
The decomposition of Cu3N into metallic copper and nitrogen was induced and characterized with a dynamic tester consisting of an optical microscope
with an integrated high power laser diode. The change in reflectivity induced by the laser pulses was measured by a high sensitivity
photo detector. Optimized Cu3N films could be decomposed into metallic copper at pulse lengths of 200 ns. The reflectivity change from 3.2% to 33.2% for
completely transformed areas and to 12% for single bits as well as the maximum write data rate of 3.3 Mbit/s demonstrated
the suitability of Cu3N for write once optical data storage. Especially the carrier to noise ratio of 41 dB shows an increase of a factor of 3 for
this novel material as compared to conventional optical data storage media. 相似文献