全文获取类型
收费全文 | 31386篇 |
免费 | 2378篇 |
国内免费 | 2335篇 |
出版年
2024年 | 46篇 |
2023年 | 386篇 |
2022年 | 1077篇 |
2021年 | 1758篇 |
2020年 | 1173篇 |
2019年 | 1580篇 |
2018年 | 1435篇 |
2017年 | 1005篇 |
2016年 | 1443篇 |
2015年 | 1996篇 |
2014年 | 2400篇 |
2013年 | 2611篇 |
2012年 | 2843篇 |
2011年 | 2559篇 |
2010年 | 1502篇 |
2009年 | 1379篇 |
2008年 | 1619篇 |
2007年 | 1432篇 |
2006年 | 1184篇 |
2005年 | 923篇 |
2004年 | 764篇 |
2003年 | 718篇 |
2002年 | 552篇 |
2001年 | 492篇 |
2000年 | 467篇 |
1999年 | 433篇 |
1998年 | 267篇 |
1997年 | 258篇 |
1996年 | 257篇 |
1995年 | 229篇 |
1994年 | 221篇 |
1993年 | 151篇 |
1992年 | 200篇 |
1991年 | 179篇 |
1990年 | 126篇 |
1989年 | 99篇 |
1988年 | 81篇 |
1987年 | 69篇 |
1986年 | 39篇 |
1985年 | 45篇 |
1984年 | 24篇 |
1983年 | 30篇 |
1982年 | 16篇 |
1981年 | 18篇 |
1980年 | 7篇 |
1979年 | 5篇 |
1965年 | 1篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
31.
Jiaohong Zhao Fudan Gao Jingsong Zhang Teruo Ogawa Weimin Ma 《The Journal of biological chemistry》2014,289(39):26669-26676
Two mutants that grew faster than the wild-type (WT) strain under high light conditions were isolated from Synechocystis sp. strain PCC 6803 transformed with a transposon-bearing library. Both mutants had a tag in ssl1690 encoding NdhO. Deletion of ndhO increased the activity of NADPH dehydrogenase (NDH-1)-dependent cyclic electron transport around photosystem I (NDH-CET), while overexpression decreased the activity. Although deletion and overexpression of ndhO did not have significant effects on the amount of other subunits such as NdhH, NdhI, NdhK, and NdhM in the cells, the amount of these subunits in the medium size NDH-1 (NDH-1M) complex was higher in the ndhO-deletion mutant and much lower in the overexpression strain than in the WT. NdhO strongly interacts with NdhI and NdhK but not with other subunits. NdhI interacts with NdhK and the interaction was blocked by NdhO. The blocking may destabilize the NDH-1M complex and repress the NDH-CET activity. When cells were transferred from growth light to high light, the amounts of NdhI and NdhK increased without significant change in the amount of NdhO, thus decreasing the relative amount of NdhO. This might have decreased the blocking, thereby stabilizing the NDH-1M complex and increasing the NDH-CET activity under high light conditions. 相似文献
32.
Journal of Plant Growth Regulation - With the increasing popularity of urban landscaping, there is a greater need to address iron deficiency and chlorosis in Cinnamomum camphora. Beneficial... 相似文献
33.
34.
35.
Mengnan Wang Dongjie Li Mingyue Zhang Wenzhi Yang Yali Cui Shijie Li 《Animal genetics》2015,46(4):354-360
The CDKN1C gene encodes a cyclin‐dependent kinase inhibitor and is one of the key genes involved in the development of Beckwith–Wiedemann syndrome and cancer. In this study, using a direct sequencing approach based on a single nucleotide polymorphism (SNP) at genomic DNA and cDNA levels, we show that CDKN1C exhibits monoallelic expression in all seven studied organs (heart, liver, spleen, lung, kidney, muscle and subcutaneous fat) in cattle. To investigate how methylation regulates imprinting of CDKN1C in cattle, allele‐specific methylation patterns in two putative differential methylation regions (DMRs), the CDKN1C DMR and KvDMR1, were analyzed in three tissues (liver, spleen and lung) using bisulfite sequencing PCR. Our results show that in the CDKN1C DMR both parental alleles were unmethylated in all three analyzed tissues. In contrast, KvDMR1 was differentially methylated between the two parental alleles in the same tissues. Statistical analysis showed that there is a significant difference in the methylation level between the two parental alleles (P < 0.01), confirming that this region is the DMR of KvDMR1 and that it may be correlated with CDKN1C imprinting. 相似文献
36.
37.
38.
Lin Xiang Lin Shuang Liu Yuanlan Zhao Haiyan Wang Li Hasi Wuliji 《Plasmonics (Norwell, Mass.)》2018,13(5):1749-1758
Plasmonics - Large-scale ordered two-dimensional (2D) superlattices at oil/water interface were fabricated using single-crystal Au nanospheres (NSs) with different diameters as building blocks. A... 相似文献
39.
Shi Fenghua Tan Muxiu Mo Qiaocheng Chen Xiaoying Zhao Yimin Guo Xiaoyun Jiang Ni 《Journal of plant biochemistry and biotechnology.》2020,29(3):528-538
Journal of Plant Biochemistry and Biotechnology - The dried buds of Lonicera hypoglauca Miq. have antipyretic, antidotal and anti-inflammatory properties and as Flos lonicerae are widely used in... 相似文献