全文获取类型
收费全文 | 9575篇 |
免费 | 816篇 |
国内免费 | 1175篇 |
专业分类
11566篇 |
出版年
2024年 | 37篇 |
2023年 | 163篇 |
2022年 | 438篇 |
2021年 | 574篇 |
2020年 | 433篇 |
2019年 | 520篇 |
2018年 | 472篇 |
2017年 | 291篇 |
2016年 | 405篇 |
2015年 | 632篇 |
2014年 | 748篇 |
2013年 | 745篇 |
2012年 | 938篇 |
2011年 | 857篇 |
2010年 | 471篇 |
2009年 | 470篇 |
2008年 | 551篇 |
2007年 | 436篇 |
2006年 | 390篇 |
2005年 | 325篇 |
2004年 | 257篇 |
2003年 | 206篇 |
2002年 | 153篇 |
2001年 | 128篇 |
2000年 | 108篇 |
1999年 | 141篇 |
1998年 | 86篇 |
1997年 | 99篇 |
1996年 | 63篇 |
1995年 | 56篇 |
1994年 | 50篇 |
1993年 | 45篇 |
1992年 | 50篇 |
1991年 | 41篇 |
1990年 | 41篇 |
1989年 | 30篇 |
1988年 | 24篇 |
1987年 | 19篇 |
1986年 | 27篇 |
1985年 | 20篇 |
1984年 | 9篇 |
1983年 | 10篇 |
1982年 | 3篇 |
1981年 | 1篇 |
1980年 | 2篇 |
1979年 | 1篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
71.
72.
73.
Fang Wang Dunmei Lin Wei Li Pengpeng Dou Le Han Mingfen Huang Shenhua Qian Jingmei Yao 《Ecology and evolution》2020,10(17):9257-9270
Litter decomposition, a fundamental process of nutrient cycling and energy flow in freshwater ecosystems, is driven by a diverse array of decomposers. As an important component of the heterotrophic food web, meiofauna can provide a trophic link between leaf‐associated microbes (i.e., bacteria and fungi)/plant detritus and macroinvertebrates, though their contribution to litter decomposition is not well understood. To investigate the role of different decomposer communities in litter decomposition, especially meiofauna, we compared the litter decomposition of three leaf species with different lignin to nitrogen ratios in litter bags with different mesh sizes (0.05, 0.25, and 2 mm) in a forested stream, in China for 78 days. The meiofauna significantly enhanced the decomposition of leaves of high‐and medium‐ quality, while decreasing (negative effect) or increasing (positive effect) the fungal biomass and diversity. Macrofauna and meiofauna together contributed to the decomposition of low‐quality leaf species. The presence of meiofauna and macrofauna triggered different aspects of the microbial community, with their effects on litter decomposition varying as a function of leaf quality. This study reveals that the meiofauna increased the trophic complexity and modulated their interactions with microbes, highlighting the important yet underestimated role of meiofauna in detritus‐based ecosystems. 相似文献
74.
Chai Qian Meng Ziang Lu Dexue Zhang Ziying Liu Meili Wu Weihua 《Molecular and cellular biochemistry》2021,476(6):2479-2489
Molecular and Cellular Biochemistry - Cardiomyocyte death is an important pathogenic process in cardiac complications of diabetes. Diabetic patients often suffer glycemic variability. Pyroptosis is... 相似文献
75.
Xiaolei Chen Zhongmei Yang Wenfeng Wang Kaiyue Qian Mingjie Liu Junchao Wang Mingzhu Wang 《Nucleic acids research》2021,49(5):2946
RBM45 is an RNA-binding protein involved in neural development, whose aggregation is associated with neurodegenerative diseases, such as amyotrophic lateral sclerosis (ALS) and frontotemporal lobar dementia (FTLD). However, the mechanisms of RNA-binding and aggregation of RBM45 remain unelucidated. Here, we report the crystal structure of the N-terminal tandem RRM domains of human RBM45 in complex with single-stranded DNA (ssDNA). Our structural and biochemical results revealed that both the RRM1 and RRM2 of RBM45 recognized the GAC sequence of RNA/ssDNA. Two aromatic residues and an arginine residue in each RRM were critical for RNA-binding, and the interdomain linker was also involved in RNA-binding. Two RRMs formed a pair of antiparallel RNA-binding sites, indicating that the N-terminal tandem RRM domains of RBM45 bound separate GAC motifs in one RNA strand or GAC motifs in different RNA strands. Our findings will be helpful in the identification of physiologic targets of RBM45 and provide evidence for understanding the physiologic and pathologic functions of RBM45. 相似文献
76.
Liu Qian Wang Zinuo Zhang Ning Zuo Jian Feng Haibo Duan Huabo 《The International Journal of Life Cycle Assessment》2021,26(6):1285-1297
The International Journal of Life Cycle Assessment - As an ambitious strategy of national interest in China and with an aim at achieving the ‘one-hour economic circle’ among Greater Bay... 相似文献
77.
Shuhao Li Yang Zou Dongping Zhao Yuqing Yin Jingyi Song Ningning He Huadong Liu Dongmeng Qian Lei Li Haiming Huang 《Protein science : a publication of the Protein Society》2021,30(3):558
Protein engineering through directed evolution is an effective way to obtain proteins with novel functions with the potential applications as tools for diagnosis or therapeutics. Many natural proteins have undergone directed evolution in vitro in the test tubes in the laboratories worldwide, resulting in the numerous protein variants with novel or enhanced functions. we constructed here an SH2 variant library by randomizing 8 variable residues in its phosphotyrosine (pTyr) binding pocket. Selection of this library by a pTyr peptide led to the identification of SH2 variants with enhanced affinities measured by EC50. Fluorescent polarization was then applied to quantify the binding affinities of the newly identified SH2 variants. As a result, three SH2 variants, named V3, V13 and V24, have comparable binding affinities with the previously identified SH2 triple‐mutant superbinder. Biolayer Interferometry assay was employed to disclose the kinetics of the binding of these SH2 superbinders to the phosphotyrosine peptide. The results indicated that all the SH2 superbinders have two‐orders increase of the dissociation rate when binding the pTyr peptide while there was no significant change in their associate rates. Intriguingly, though binding the pTyr peptide with comparable affinity with other SH2 superbinders, the V3 does not bind to the sTyr peptide. However, variant V13 and V24 have cross‐reactivity with both pTyr and sTyr peptides. The newly identified superbinders could be utilized as tools for the identification of pTyr‐containing proteins from tissues under different physiological or pathophysiological conditions and may have the potential in the therapeutics. 相似文献
78.
79.
80.
Dong Haoru Shu Xinhua Xu Qiang Zhu Chen Kaufmann Andreas M. Zheng Zhi-Ming Albers Andreas E. Qian Xu 《中国病毒学》2021,36(6):1284-1302
Virologica Sinica - Human papillomavirus (HPV) infection identified as a definitive human carcinogen is increasingly being recognized for its role in carcinogenesis of human cancers. Up to... 相似文献