全文获取类型
收费全文 | 94372篇 |
免费 | 336篇 |
国内免费 | 812篇 |
出版年
2022年 | 12篇 |
2021年 | 27篇 |
2020年 | 17篇 |
2019年 | 29篇 |
2018年 | 11856篇 |
2017年 | 10694篇 |
2016年 | 7479篇 |
2015年 | 631篇 |
2014年 | 341篇 |
2013年 | 367篇 |
2012年 | 4291篇 |
2011年 | 12881篇 |
2010年 | 12044篇 |
2009年 | 8274篇 |
2008年 | 9848篇 |
2007年 | 11417篇 |
2006年 | 328篇 |
2005年 | 558篇 |
2004年 | 1024篇 |
2003年 | 1065篇 |
2002年 | 827篇 |
2001年 | 270篇 |
2000年 | 181篇 |
1999年 | 47篇 |
1998年 | 17篇 |
1997年 | 33篇 |
1996年 | 22篇 |
1995年 | 8篇 |
1994年 | 17篇 |
1993年 | 38篇 |
1992年 | 37篇 |
1991年 | 51篇 |
1990年 | 22篇 |
1989年 | 11篇 |
1988年 | 24篇 |
1987年 | 24篇 |
1986年 | 7篇 |
1984年 | 15篇 |
1983年 | 23篇 |
1982年 | 8篇 |
1978年 | 6篇 |
1976年 | 7篇 |
1975年 | 10篇 |
1972年 | 248篇 |
1971年 | 278篇 |
1970年 | 8篇 |
1965年 | 13篇 |
1962年 | 24篇 |
1944年 | 12篇 |
1940年 | 10篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
251.
252.
253.
254.
255.
The effect of algae on the production of musty-smelling compounds by actinomycetes was studied. Streptomyces spp., causing intensive musty odor, were isolated from hypertrophic Lake Kasumigaura and cultured in association with algae from the same lake. Isolate E and I effectively utilized the cyanobacteria, Microcystis aeruginosa and Anabaena spiroides, and the diatom, Synedra acus, as a carbon source and produced a musty-smelling 2-methylisoborneol in the shaken sediment cultures. High populations of algae and actinomycetes, and aerobic condition in the sediment seem responsible for the occurrence of musty odor in Lake Kasumigaura. 相似文献
256.
257.
Maxim K. Elias 《Pal?ontologische Zeitschrift》1962,36(1):29-37
The type specimen ofGonioloboceras goniolobum (Meek), rediscovered by Spath in the British Museum, is the foundation for a more accurate comparative study of this and other species ofGonioloboceras.Gonioloboceras described asG. goniolobum byElias in 1938 is differentiated asGonioloboceras schmidti, new species. Suture sets (new term) for several growth stages inG. goniolobum (Meek),G. welleriSmith,G. schmidtiElias, G.eliasiMiller &Owen, andG. asiaticumLibrovitch are assembled and used for differentiation of the species.The Kazakhstan goniatite faunule containingG. asiaticum is considered of very late Pennsylvanian age. 相似文献
258.
R. Schoysman B. Lejeune E. Van Roosendaal L. Segal P. Vanderzwalmen M. Nijs B. Vandamme G. Bertin 《Andrologie》1996,6(4):432-439
The authors report their experience with the use of spermatids in TESE programs where mature spermatozoa could not be isolated from testicular biopsies. The details of the indications for spermatid insemination, the technicity of the procedure and the results are exposed. 相似文献
259.
260.
Adobati Elena; Panza Luigi; Russo Giovanni; Colnaghi Maria I.; Canevari Silvana 《Glycobiology》1997,7(2):173-178
The murine monoclonal antibody (Mab) MBr1, raised against thebreast cancer cell line MCF7, recognizes a saccharidic epitopeoverexpressed on a high percentage of human breast, ovary, andlung carcinomas. This antigen was originally identified on theimmunogen as a globo-series glycosphingolipid with an H-likedeterminant at its terminus (globo-H). We report here the biologicalcharacterization of the entire globo-H hexasaccharide and fivesynthetic oligosaccharides representing fragments of the entirestructure andlor different anomeric configurations. Using competitivebinding assays on live cells, we identified the residues andthe linkages essential for mimicry of the cellular antigensrecognized by Mab MBr1 on the breast carcinoma cell line MCF7and small cell lung cancer cell line POVD. The terminal tetrasaccharidicfragment of globo-H is the oligosaccharide that most resemblesthe MBr1-defined epitope both on glycolipids and on glycoproteins.This information will help in the rational design of a highlyspecific reagent for active specific immunotherapy of carcinomasoverexpressing the MBr1-defined antigen. CaMBr1 immunotherapy monoclonal antibody oligosaccharides tumor-associated antigen 相似文献