全文获取类型
收费全文 | 957篇 |
免费 | 66篇 |
专业分类
化学 | 879篇 |
晶体学 | 2篇 |
力学 | 6篇 |
数学 | 72篇 |
物理学 | 64篇 |
出版年
2023年 | 4篇 |
2021年 | 10篇 |
2020年 | 14篇 |
2019年 | 13篇 |
2018年 | 9篇 |
2016年 | 26篇 |
2015年 | 34篇 |
2014年 | 35篇 |
2013年 | 43篇 |
2012年 | 60篇 |
2011年 | 60篇 |
2010年 | 44篇 |
2009年 | 44篇 |
2008年 | 39篇 |
2007年 | 54篇 |
2006年 | 47篇 |
2005年 | 50篇 |
2004年 | 43篇 |
2003年 | 54篇 |
2002年 | 41篇 |
2001年 | 20篇 |
2000年 | 24篇 |
1999年 | 30篇 |
1998年 | 23篇 |
1997年 | 18篇 |
1996年 | 17篇 |
1995年 | 24篇 |
1994年 | 20篇 |
1993年 | 16篇 |
1992年 | 23篇 |
1991年 | 8篇 |
1990年 | 10篇 |
1988年 | 7篇 |
1986年 | 8篇 |
1985年 | 6篇 |
1984年 | 4篇 |
1983年 | 3篇 |
1982年 | 7篇 |
1981年 | 6篇 |
1980年 | 3篇 |
1979年 | 3篇 |
1978年 | 3篇 |
1977年 | 2篇 |
1975年 | 2篇 |
1972年 | 1篇 |
1970年 | 1篇 |
1968年 | 1篇 |
1966年 | 1篇 |
1956年 | 2篇 |
1955年 | 1篇 |
排序方式: 共有1023条查询结果,搜索用时 421 毫秒
111.
Isidoro Lpez Mehmed Z. Ertem Somnath Maji Jordi Benet‐Buchholz Anke Keidel Uwe Kuhlmann Peter Hildebrandt Christopher J. Cramer Victor S. Batista Antoni Llobet 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2014,126(1):209-213
The homogeneous catalysis of water oxidation by transition‐metal complexes has experienced spectacular development over the last five years. Practical energy‐conversion schemes, however, require robust catalysts with large turnover frequencies. Herein we introduce a new oxidatively rugged and powerful dinuclear water‐oxidation catalyst that is generated by self‐assembly from a mononuclear catalyst during the catalytic process. Our kinetic and DFT computational analysis shows that two interconnected catalytic cycles coexist while the mononuclear system is slowly and irreversibly converted into the more stable dinuclear system: an extremely robust water‐oxidation catalyst that does not decompose over extended periods of time. 相似文献
112.
113.
Seven diterpenoids, isolated due to their ability to inhibit spore germination in the plant pathogenic fungus Magnaporthe grisea, were obtained from cultures of the basidiomycete Coprinus heptemerus. The structures of the compounds, named heptemerones A-G, were determined with spectroscopic techniques. 相似文献
114.
115.
116.
117.
118.
S. Diederich 《Zeitschrift für Physik A Hadrons and Nuclei》1968,213(3):233-243
Employing perturbation theory aK +-meson proton potential resulting from two-pion exchange is obtained. Recoil effects are taken into account. For short distances we add a phenomenological hard core interaction and calculates-wave phase shifts. 相似文献
119.
Tracy P. Houghton David N. Thompson J. Richard Hess Jeffrey A. Lacey Michael P. Wolcott Anke Schirp Karl Englund David Dostal Frank Loge 《Applied biochemistry and biotechnology》2004,113(1-3):71-93
Combining biologic pretreatment with storage is an innovative approach for improving feedstock characteristics and cost, but
the magnitude of responses of such systems to upsets is unknown. Unsterile wheat straw stems were upgraded for 12 wk with
Pleurotus ostreatus at constant temperature to estimate the variation in final compositions with variations in initial moisture and inoculum.
Degradation rates and conversions increased with both moisture and inoculum. A regression analysis indicated that system performance
was quite stable with respect to inoculum and moisture content after 6 wk of treatment. Scale-up by 150× indicated that system
stability and final straw composition are sensitive to inoculum source, history, and inoculation method. Comparative testing
of straw-thermoplastic composites produced from upgraded stems is under way. 相似文献
120.