全文获取类型
收费全文 | 10430篇 |
免费 | 422篇 |
国内免费 | 81篇 |
专业分类
化学 | 7490篇 |
晶体学 | 64篇 |
力学 | 140篇 |
数学 | 1549篇 |
物理学 | 1690篇 |
出版年
2023年 | 64篇 |
2022年 | 98篇 |
2021年 | 117篇 |
2020年 | 222篇 |
2019年 | 181篇 |
2018年 | 106篇 |
2017年 | 87篇 |
2016年 | 285篇 |
2015年 | 228篇 |
2014年 | 266篇 |
2013年 | 507篇 |
2012年 | 543篇 |
2011年 | 620篇 |
2010年 | 375篇 |
2009年 | 334篇 |
2008年 | 563篇 |
2007年 | 548篇 |
2006年 | 558篇 |
2005年 | 521篇 |
2004年 | 439篇 |
2003年 | 330篇 |
2002年 | 393篇 |
2001年 | 184篇 |
2000年 | 189篇 |
1999年 | 165篇 |
1998年 | 170篇 |
1997年 | 152篇 |
1996年 | 161篇 |
1995年 | 133篇 |
1994年 | 156篇 |
1993年 | 132篇 |
1992年 | 114篇 |
1991年 | 112篇 |
1990年 | 93篇 |
1989年 | 76篇 |
1988年 | 64篇 |
1987年 | 68篇 |
1986年 | 57篇 |
1985年 | 112篇 |
1984年 | 98篇 |
1983年 | 68篇 |
1982年 | 106篇 |
1981年 | 92篇 |
1980年 | 79篇 |
1979年 | 95篇 |
1978年 | 88篇 |
1977年 | 79篇 |
1976年 | 87篇 |
1975年 | 63篇 |
1974年 | 58篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
41.
42.
43.
We give a competitive algorithm to identify all d defective edges in a hypergraph with d unknown. Damaschke did the d=1 case for 2-graphs, Triesch extended the d=1 case to r-graphs, and Johann did the general d case for 2-graphs. So ours is the first attempt to solve the searching for defective edges problem in its full generality. Further, all the above three papers assumed d known. We give a competitive algorithm where d is unknown. 相似文献
44.
45.
We consider a specific continuous-spin Gibbs distribution μt=0 for a double-well potential that allows for ferromagnetic ordering. We study the time-evolution of this initial measure under
independent diffusions.
For `high temperature' initial measures we prove that the time-evoved measure μt is Gibbsian for all t. For `low temperature' initial measures we prove that μt stays Gibbsian for small enough times t, but loses its Gibbsian character for large enough t. In contrast to the analogous situation for discrete-spin Gibbs measures, there is no recovery of the Gibbs property for
large t in the presence of a non-vanishing external magnetic field. All of our results hold for any dimension d≥2. This example suggests more generally that time-evolved continuous-spin models tend to be non-Gibbsian more easily than
their discrete-spin counterparts.
Research carried out at EURANDOM and supported by Deutsche Forschungsgemeinschaft 相似文献
46.
A palladium-catalyzed parallel synthesis of bis-hetero(aryl) ketones is described with two further synthetic steps allowing easy entry to 3,3-di(hetero)arylpropylamines. 相似文献
47.
48.
Björn Wängler Carmen Beck Esther Schirrmacher Frank Rösch Michael Eisenhut 《Tetrahedron letters》2006,47(33):5985-5988
The synthesis of tris-allyl-DOTA starting from cyclen and its application in the preparation of DOTA-peptide conjugates is reported. Clinically important conjugates such as DOTA-Tyr3-octreotide (DOTA-TOC), DOTA-Tyr3-octreotate (DOTA-TATE) as well as a DOTA-RGD peptide were synthesized in high yields with Fmoc solid phase peptide synthesis. The final, extremely reliable de-allylation was achieved on solid phase by different methods identifying morpholine/Pd(0) as the most suitable one obtaining all DOTA peptide conjugates in high yields. All DOTA-peptides were purified by reversed phase HPLC and structural identity was proved using MALDI-TOF mass spectrometry. 相似文献
49.
K. C. Nicolaou Dionisios Vourloumis Tianhu Li Joaquin Pastor Nicolas Winssinger Yun He Sacha Ninkovic Francisco Sarabia Hans Vallberg Frank Roschangar N. Paul King M. Ray V. Finlay Pareskevi Giannakakou Pascal Verdier-Pinard Ernest Hamel 《Angewandte Chemie (International ed. in English)》1997,36(19):2097-2103
50.