全文获取类型
收费全文 | 829篇 |
免费 | 54篇 |
国内免费 | 4篇 |
专业分类
化学 | 622篇 |
晶体学 | 6篇 |
力学 | 12篇 |
数学 | 103篇 |
物理学 | 144篇 |
出版年
2023年 | 9篇 |
2022年 | 12篇 |
2021年 | 9篇 |
2020年 | 18篇 |
2019年 | 22篇 |
2018年 | 8篇 |
2017年 | 12篇 |
2016年 | 38篇 |
2015年 | 31篇 |
2014年 | 27篇 |
2013年 | 45篇 |
2012年 | 40篇 |
2011年 | 71篇 |
2010年 | 40篇 |
2009年 | 42篇 |
2008年 | 49篇 |
2007年 | 25篇 |
2006年 | 40篇 |
2005年 | 31篇 |
2004年 | 36篇 |
2003年 | 21篇 |
2002年 | 23篇 |
2001年 | 15篇 |
2000年 | 16篇 |
1999年 | 11篇 |
1998年 | 7篇 |
1997年 | 7篇 |
1996年 | 10篇 |
1995年 | 6篇 |
1993年 | 4篇 |
1992年 | 7篇 |
1989年 | 5篇 |
1987年 | 7篇 |
1986年 | 4篇 |
1985年 | 4篇 |
1984年 | 4篇 |
1983年 | 5篇 |
1982年 | 4篇 |
1980年 | 9篇 |
1978年 | 5篇 |
1977年 | 11篇 |
1976年 | 7篇 |
1975年 | 7篇 |
1970年 | 6篇 |
1934年 | 4篇 |
1926年 | 3篇 |
1925年 | 3篇 |
1924年 | 3篇 |
1923年 | 5篇 |
1899年 | 4篇 |
排序方式: 共有887条查询结果,搜索用时 15 毫秒
71.
Georg Gregor 《Monatshefte für Chemie / Chemical Monthly》1894,15(1):437-445
Ohne Zusammenfassung 相似文献
72.
Ingo Klimant Falk Ruckruh Gregor Liebsch Achim Stangelmayer Otto S. Wolfbeis 《Mikrochimica acta》1999,131(1-2):35-46
A new type of phenyl substituted ormosils as a matrix for oxygen-sensitive micro-optodes is described. The new ormosils combine
features of classical polymers such as solubility in organic solvents and those of sol–gel glasses such as mechanical stability
and a porous structure. They make possible a simple and fast fabrication of microsensors with reproducible properties. The
influence of the conditions during the polymerisation process (precursor composition and thermal treatment) on the sensing
properties has been studied in detail. Oxygen-sensitive films with ruthenium(II)–tris-(4,7-diphenyl-1,10-phenanthroline) and
platinum(II)–octaethylporphyrin as indicators were characterised with respect to their mechanical and photophysical properties.
Photostability, oxygen sensitivity, response behaviour and signal intensities of the sensing films and the micro-optodes were
examined. Micro-optodes based on the new sensing materials are fast responding, photostable and can be produced with a sufficient
batch to batch reproducibility. Compared to previously described oxygen micro-optodes, where polystyrene was used as immobilisation
matrix, the new sensors can be autoclaved and show favourable properties such as a faster response and a higher sensitivity.
They possess many potential applications in medical and biological research.
Received June 12, 1998. Revision December 10, 1998. 相似文献
73.
74.
75.
76.
77.
O. Anselmino Stone Tollens L. Rosenthaler E. Spaeth Caesar Loretz Panchaud B. Hafner E. W. Mann John Barclay Fromme Fraser Ludwig Krauss P. Lemaire Denigés Kimpflin M. Nussbaum H. Runne C. Guérin G. Denigés Feldhaus Gregor E. Durien Fordos Geélis Utscher C. Gueérin Ernst Deussen E. Beckmann 《Analytical and bioanalytical chemistry》1912,51(10-11):700-712
78.
L. Pecha J. Bankovskis A. Kemme V. Bel'sky E. Silin' J. Asaks 《Chemistry of Heterocyclic Compounds》2002,38(6):695-699
Tris(8-mercaptoquinolinato)thallium Tl(C9H6NS)3 and tris(8-hydroxyquinolinato)thallium monohydrate Tl(C9H6NO)3·H2O have been synthesized. Their structures have been confirmed by X-ray crystallographic analysis. 相似文献
79.
Richard Pibram und Georg Gregor 《Fresenius' Journal of Analytical Chemistry》1899,38(7):401-411
Ohne Zusammenfassung 相似文献
80.
A. Zablotskaya I. Segal A. Kemme S. Germane J. Popelis E. Lukevics R. Berger H. Spies 《Chemistry of Heterocyclic Compounds》2002,38(4):477-489
With the aim of studying the structure-physicochemical properties-biological activity relation, we have synthesized a series of organosilicon neutral oxorhenium(V) complexes with mixed ligands and we have determined their lipophilicity. X-ray diffraction has been used to establish the molecular structure of (3-triphenylsiloxypropanethiolato)(3-thiapentane-1,5-dithiolato)oxorhenium(V), (2-trimethylsiloxy- and 2-hydroxyethanethiolato)[3-(N-methyl)azapentane-1,5-dithiolato]oxorhenium(V). We have studied the neurotropic properties and acute toxicity of the synthesized complexes in vivo and their dependence on the nature of the monodentate and tridentate ligands. We have established that all the studied compounds have pronounced sedative action (they prolong the life of mice under hypoxia conditions, they are phenamine antagonists, they exhibit anticonvulsive action and prevent retrograde amnesia). 相似文献