全文获取类型
收费全文 | 1013篇 |
免费 | 30篇 |
出版年
2015年 | 13篇 |
2014年 | 11篇 |
2013年 | 20篇 |
2012年 | 15篇 |
2011年 | 21篇 |
2010年 | 29篇 |
2009年 | 27篇 |
2008年 | 37篇 |
2007年 | 51篇 |
2006年 | 23篇 |
2005年 | 29篇 |
2004年 | 17篇 |
2003年 | 12篇 |
2002年 | 18篇 |
2001年 | 12篇 |
2000年 | 17篇 |
1999年 | 18篇 |
1997年 | 19篇 |
1996年 | 14篇 |
1995年 | 13篇 |
1994年 | 13篇 |
1993年 | 17篇 |
1992年 | 11篇 |
1991年 | 20篇 |
1990年 | 17篇 |
1989年 | 13篇 |
1988年 | 12篇 |
1987年 | 17篇 |
1986年 | 14篇 |
1985年 | 11篇 |
1984年 | 13篇 |
1982年 | 13篇 |
1980年 | 12篇 |
1979年 | 11篇 |
1976年 | 13篇 |
1975年 | 11篇 |
1974年 | 17篇 |
1973年 | 18篇 |
1972年 | 16篇 |
1971年 | 10篇 |
1968年 | 10篇 |
1965年 | 36篇 |
1964年 | 19篇 |
1963年 | 32篇 |
1962年 | 23篇 |
1961年 | 33篇 |
1960年 | 21篇 |
1959年 | 27篇 |
1958年 | 27篇 |
1957年 | 12篇 |
排序方式: 共有1043条查询结果,搜索用时 140 毫秒
51.
SYNOPSIS. Supraspecific taxa of the ciliate Order Tintinnida Corliss, 1955 are indexed by 304 entries; genetic type species are cited with reference to the original citation. The accompanying bibliography of 133 entries includes those publications cited in the index. Authors for several type citations are corrected, as is authorship of some genera, and a new type designation is made for Parundella to replace the previous erroneous designation. Genera present in the fossil record are so indicated. 相似文献
52.
53.
Cell-free extracts of a bacteria-free culture of Nostoc muscorumwere used to demonstrate the occurrence of part of the KREBS-HENSELEITornithine cycle in blue-green algae. Evidence is presented forthe conversion of ammonia and bicarbonate to carbamyl phosphateand the coupling of carbamyl phosphate to ornithtne to yieldcitrulline. Attempts to demonstrate the conversion of citrullineto arginine were not successful.
1Present address: Scripts Institute of Oceanography, Universityof California, La Jolla, California, U.S.A.
2Present address: Department of Biochemistry and Nutrition,The University of Texas Medical Branch, Galveston, Texas, U.S.A. 相似文献
54.
55.
56.
57.
58.
SYNOPSIS. The mechanism of carbohydrate dissimilation was studied in cell-free extracts prepared from mass cultures of the trichomonads. Evidence for the presence of all the enzymes associated with the Embden-Meyerhof glycolytic scheme was obtained. Several enzyme systems directly associated with the glycolytic pathway were examined. Two of these, alcohol dehydrogenase and phosphorylase, were not demonstrated in the T. vaginalis extract. The absence of phosphorylase in the presence of a very high glycogen concentration in the cell (20.8%) suggests the possibility of an alternate route. A very active TPN-linked "malic enzyme" was also demonstrated, although no functional citric acid cycle is known for this trichomonad. Based on the experimental evidence and collateral data, a functional Embden-Meyerhof system was suggested for T. vaginalis. 相似文献
59.
60.