全文获取类型
收费全文 | 20612篇 |
免费 | 1958篇 |
国内免费 | 3332篇 |
出版年
2024年 | 66篇 |
2023年 | 327篇 |
2022年 | 774篇 |
2021年 | 1267篇 |
2020年 | 995篇 |
2019年 | 1122篇 |
2018年 | 984篇 |
2017年 | 732篇 |
2016年 | 1004篇 |
2015年 | 1487篇 |
2014年 | 1742篇 |
2013年 | 1794篇 |
2012年 | 2216篇 |
2011年 | 1962篇 |
2010年 | 1245篇 |
2009年 | 1164篇 |
2008年 | 1228篇 |
2007年 | 1002篇 |
2006年 | 893篇 |
2005年 | 742篇 |
2004年 | 631篇 |
2003年 | 560篇 |
2002年 | 428篇 |
2001年 | 298篇 |
2000年 | 244篇 |
1999年 | 236篇 |
1998年 | 129篇 |
1997年 | 90篇 |
1996年 | 92篇 |
1995年 | 94篇 |
1994年 | 62篇 |
1993年 | 47篇 |
1992年 | 41篇 |
1991年 | 47篇 |
1990年 | 28篇 |
1989年 | 26篇 |
1988年 | 12篇 |
1987年 | 13篇 |
1986年 | 11篇 |
1985年 | 14篇 |
1984年 | 10篇 |
1983年 | 12篇 |
1982年 | 13篇 |
1981年 | 4篇 |
1979年 | 2篇 |
1976年 | 2篇 |
1965年 | 1篇 |
1955年 | 1篇 |
1951年 | 2篇 |
1950年 | 1篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
71.
72.
Xiaofen Tan Yifan Wen Zhijun Han Xuyang Su Jing Peng Feng Chen Yadong Wang Tianming Wang Changzhong Wang Kelong Ma 《化学与生物多样性》2023,20(2):e202200089
73.
Genetically and phenotypically identical immune cell populations can be highly heterogenous in terms of their immune functions and protein secretion profiles. The microfluidic chip-based single-cell highly multiplexed secretome proteomics enables characterization of cellular heterogeneity of immune responses at different cellular and molecular layers. Increasing evidence has demonstrated that polyfunctional T cells that simultaneously produce 2+ proteins per cell at the single-cell level are key effector cells that contribute to the development of potent and durable cellular immunity against pathogens and cancers. The functional proteomic technology offers a wide spectrum of cellular function assessment and can uniquely define highly polyfunctional cell subsets with cytokine signatures from live individual cells. This high-dimensional single-cell analysis provides deep dissection into functional heterogeneity and helps identify predictive biomarkers and potential correlates that are crucial for immunotherapeutic product design optimization and personalized immunotherapy development to achieve better clinical outcomes. 相似文献
74.
75.
76.
77.
78.
Li-Jun Yan Zhi-Guo Zhu Pei Wang Chao-Nan Fu Xi-Jin Guan Philip Kear Chun-Zhi Zhang Guang-Tao Zhu 《植物分类学报:英文版》2023,61(4):599-612
Common potato (Solanum tuberosum L.) and its wild relatives belong to Solanum section Petota. This section's phylogeny and species delimitation are complicated due to various ploidy levels, high heterozygosity, and frequent interspecific hybridization. Compared to the nuclear genome, the plastid genome is more conserved, has a haploid nature, and has a lower nucleotide substitution rate, providing informative alternative insights into the phylogenetic study of section Petota. Here, we analyzed 343 potato plastid genomes from 53 wild and four cultivated species. The diversity of sequences and genomes was comprehensively analyzed. A total of 24 species were placed in a phylogenetic tree based on genomic data for the first time. Overall, our results not only confirmed most existing clades and species boundaries inferred by nuclear evidence but also provided some distinctive species clade belonging and the maternally inherited evidence supporting the hybrid origin of some species. Furthermore, the divergence times between the major potato clades were estimated. In addition, the species discriminatory power of universal barcodes, nuclear ribosomal DNA, and whole and partial plastid genomes and their combinations were thoroughly evaluated; the plastid genome performed best but had limited discriminatory power for all survey species (40%). Overall, our study provided not only new insights into phylogeny and DNA barcoding of potato but also provided valuable genetic data resources for further systematical research of Petota. 相似文献
79.
Jing‐Fang Guo Baosheng Wang Zhan‐Lin Liu Jian‐Feng Mao Xiao‐Ru Wang Wei Zhao 《植物分类学报:英文版》2023,61(1):143-156
Endemic species are important components of regional biodiversity and hold the key to understanding local adaptation and evolutionary processes that shape species distributions. This study investigated the biogeographic history of a relict conifer Pinus bungeana Zucc. ex Endl. confined to central China. We examined genetic diversity in P. bungeana using genotyping-by-sequencing and chloroplast and mitochondrial DNA markers. We performed spatial and temporal inference of recent genetic and demographic changes, and dissected the impacts of geography and environmental gradients on population differentiation. We then projected P. bungeana's risk of decline under future climates. We found extremely low nucleotide diversity (average π 0.0014), and strong population structure (global FST 0.234) even at regional scales, reflecting long-term isolation in small populations. The species experienced severe bottlenecks in the early Pliocene and continued to decline in the Pleistocene in the western distribution, whereas the east expanded recently. Local adaptation played a small (8%) but significant role in population diversity. Low genetic diversity in fragmented populations makes the species highly vulnerable to climate change, particularly in marginal and relict populations. We suggest that conservation efforts should focus on enhancing gene pool and population growth through assisted migration within each genetic cluster to reduce the risk of further genetic drift and extinction. 相似文献