全文获取类型
收费全文 | 18336篇 |
免费 | 1555篇 |
国内免费 | 4篇 |
专业分类
19895篇 |
出版年
2023年 | 65篇 |
2022年 | 151篇 |
2021年 | 317篇 |
2020年 | 174篇 |
2019年 | 230篇 |
2018年 | 319篇 |
2017年 | 280篇 |
2016年 | 402篇 |
2015年 | 790篇 |
2014年 | 844篇 |
2013年 | 1063篇 |
2012年 | 1482篇 |
2011年 | 1452篇 |
2010年 | 876篇 |
2009年 | 865篇 |
2008年 | 1195篇 |
2007年 | 1211篇 |
2006年 | 1102篇 |
2005年 | 1118篇 |
2004年 | 985篇 |
2003年 | 925篇 |
2002年 | 900篇 |
2001年 | 188篇 |
2000年 | 138篇 |
1999年 | 185篇 |
1998年 | 271篇 |
1997年 | 159篇 |
1996年 | 144篇 |
1995年 | 142篇 |
1994年 | 124篇 |
1993年 | 115篇 |
1992年 | 96篇 |
1991年 | 82篇 |
1990年 | 91篇 |
1989年 | 87篇 |
1988年 | 77篇 |
1987年 | 55篇 |
1986年 | 74篇 |
1985年 | 76篇 |
1984年 | 97篇 |
1983年 | 75篇 |
1982年 | 86篇 |
1981年 | 104篇 |
1980年 | 88篇 |
1979年 | 56篇 |
1978年 | 66篇 |
1977年 | 53篇 |
1976年 | 38篇 |
1974年 | 56篇 |
1973年 | 35篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
21.
22.
23.
24.
Strategies for signal amplification in nucleic acid detection 总被引:3,自引:0,他引:3
S. Calin Andras J. Brian Power Edward C. Cocking Michael R. Davey 《Molecular biotechnology》2001,19(1):29-44
Many aspects of molecular genetics necessitate the detection of nucleic acid sequences. Current approaches involving target
amplification (in situ PCR, Primed in situ Labeling, Self-Sustained Sequence Replication, Strand Displacement Amplification), probe amplification (Ligase Chain Reaction,
Padlock Probes, Rolling Circle Amplification) and signal amplification (Tyramide Signal Amplification, Branched DNA Amplification)
are summarized in the present review, together with their advantages and limitations. 相似文献
25.
Using two-dimensional polyacrylamide gel electrophoresis, the GroEL homologue ofBacillus subtilis was shown to be induced upon infection with Ø105clz, a clear plaque mutant of the temperate bacteriophage Ø105. Western blotting of one dimensional polyacrylamide gels also showed the induction of the GroEL homologue when cells were infected with Ø105clz. 相似文献
26.
27.
Summary Microorganisms were able to remove hydrocarbons (pentane and isobutane) from air by biological action in a columnar bioreactor with ceramic packing. The reactor was operated in a liquid continuous mode with gas recirculation and a slow addition of the organic-containing air. After a period of acclimation, the reactor has operated for 12 months with only pentane and isobutane as carbon sources. The gaseous hydrocarbons have been degraded throughout this period. The hydrocarbon removal rates measured between 1 and 2 g h–1 m–3. The microbes were shown to be able to degrade these gaseous hydrocarbons completely in a closed bioreactor without any additional nutrients.Research supported by the Advanced Industrial Concepts Division-Biological and Chemical Technologies Research. U.S. Department of Energy, under contract DE-AC05-84OR21400 with Martin Marietta Energy Systems. Inc. 相似文献
28.
29.
30.
Zabardast T. Buriev Sukumar Saha Ibrokhim Y. Abdurakhmonov Johnie N. Jenkins Abdusattor Abdukarimov Brian E. Scheffler David M. Stelly 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2010,120(3):587-606
MIC-3 is a recently identified gene family shown to exhibit increased root-specific expression following nematode infection of
cotton plants that are resistant to root-knot nematode. Here, we cloned and sequenced MIC-3 genes from selected diploid and tetraploid cotton species to reveal sequence differences at the molecular level and identify
chromosomal locations of MIC-3 genes in Gossypium species. Detailed sequence analysis and phylogenetic clustering of MIC-3 genes indicated the presence of multiple MIC-3 gene members in Gossypium species. Haplotypes of a MIC-3 gene family member were discovered by comparative analysis among consensus sequences across genotypes within an individual
clade in the phylogram to overcome the problem of duplicated loci in the tetraploid cotton. Deficiency tests of the SNPs delimited
six At-genome members of the MIC-3 family clustered to chromosome arm 4sh, and one Dt-genome member to chromosome 19. Clustering was confirmed by long-PCR amplification of the intergenic regions using At-genome-specific MIC-3 primer pairs. The clustered distribution may have been favored by selection for responsiveness to evolving disease and/or
pest pressures, because large variants of the MIC-3 gene family may have been recovered from small physical areas by recombination. This could give a buffer against selection
pressure from a broad range of pest and pathogens in the future. To our knowledge, these are the first results on the evolution
of clustering and genome-specific haplotype members of a unique cotton gene family associated with resistant response against
a major pathogen. 相似文献