全文获取类型
收费全文 | 25642篇 |
免费 | 1371篇 |
国内免费 | 32篇 |
专业分类
27045篇 |
出版年
2023年 | 215篇 |
2022年 | 463篇 |
2021年 | 884篇 |
2020年 | 510篇 |
2019年 | 569篇 |
2018年 | 821篇 |
2017年 | 758篇 |
2016年 | 982篇 |
2015年 | 1155篇 |
2014年 | 1446篇 |
2013年 | 1983篇 |
2012年 | 2074篇 |
2011年 | 1880篇 |
2010年 | 1093篇 |
2009年 | 954篇 |
2008年 | 1160篇 |
2007年 | 1105篇 |
2006年 | 963篇 |
2005年 | 902篇 |
2004年 | 737篇 |
2003年 | 606篇 |
2002年 | 580篇 |
2001年 | 498篇 |
2000年 | 450篇 |
1999年 | 407篇 |
1998年 | 153篇 |
1997年 | 132篇 |
1996年 | 146篇 |
1995年 | 126篇 |
1994年 | 110篇 |
1993年 | 91篇 |
1992年 | 263篇 |
1991年 | 253篇 |
1990年 | 196篇 |
1989年 | 178篇 |
1988年 | 210篇 |
1987年 | 185篇 |
1986年 | 163篇 |
1985年 | 171篇 |
1984年 | 162篇 |
1983年 | 96篇 |
1982年 | 84篇 |
1981年 | 89篇 |
1980年 | 91篇 |
1979年 | 130篇 |
1978年 | 90篇 |
1977年 | 90篇 |
1976年 | 73篇 |
1974年 | 68篇 |
1973年 | 71篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
21.
R K Sharma 《Biochemical and biophysical research communications》1991,181(1):493-497
Polyclonal antibodies raised against bovine heart high molecular weight calmodulin-binding protein were used to study the distribution of this protein in diverse bovine tissues. The high molecular weight calmodulin-binding protein, in addition to bovine heart, is also present in lung and brain at much lower levels, but not in skeletal muscle, spleen, kidney or uterus. 相似文献
22.
K Muralidhar T Rajendrakumar H P Sharma 《Indian journal of biochemistry & biophysics》1992,29(2):168-172
Lutropin (LH-1) from water buffaloes has been shown to exhibit microheterogeneity in the N-terminal amino-acid sequence of its alpha-subunit. The beta-subunit did not exhibit such microheterogeneity. Another protocol of purification yielded a preparation of buffalo LH (bu LH-2) different from the buffalo LH-1 in certain physico-chemical properties like ease of dissociation into subunits, sugar composition, isoelectric point, and elution profile on S-200. Data appear to indicate the presence of more than one form of buffalo lutropin. 相似文献
23.
24.
Summary On a Typic Ustochrept soil incorporation of 10 tons/ha of a green manure plus submergence for 10 days followed by raising upland nursery checked iron chlorosis. In contrast, presubmergence with and without FYM and iron sulfate or pyrite were a failure. Nor weekly sprays with 3.0% iron sulfate were found very effective. The success of green manure plus submergence was associated with the mobilization of soil iron as a result of intense reduction and its subsequent retention in available form at a sufficient high level during the growth of upland nursery. 相似文献
25.
26.
27.
28.
29.
Dipak Kumar Banerjee 《Journal of biosciences》1987,11(1-4):311-319
Radio-labelled amphomycin (3H-amphomycin) forms a complex with dolichylmonophosphate in presence of Ca2+. Complex formation has also been documented with retinylmonophosphate and perhydromonoeneretinylmonophosphate. Analysis of
the space-filling model suggested both fatty acylated aspartic acid residue at the N-terminus of the lipopeptide and phosphate
head group of dolichylmonophosphate are necessary for the complex formation. The binding ability of amphomycin is then utilized
to localize dolichylmonophosphate in the microsomal membrane. Studies with microsomal membranes from hen oviduct suggested
that dolichylmonophosphate is located in the cytoplasmic side of the membrane. 相似文献
30.
Ten species of Lepadella Bory de St. Vincent, 1826, including one new species and one new form, are documented from North-Eastern India. Two of these species are new records from this country and six are new reports from N.E. region. Comments are also made on the status and distribution of various Indian taxa. 相似文献