全文获取类型
收费全文 | 187335篇 |
免费 | 10303篇 |
国内免费 | 8899篇 |
出版年
2023年 | 1267篇 |
2022年 | 1608篇 |
2021年 | 5347篇 |
2020年 | 3828篇 |
2019年 | 4708篇 |
2018年 | 5266篇 |
2017年 | 4253篇 |
2016年 | 7290篇 |
2015年 | 12653篇 |
2014年 | 13424篇 |
2013年 | 13610篇 |
2012年 | 14495篇 |
2011年 | 10793篇 |
2010年 | 7511篇 |
2009年 | 6903篇 |
2008年 | 6181篇 |
2007年 | 5549篇 |
2006年 | 4915篇 |
2005年 | 9928篇 |
2004年 | 8154篇 |
2003年 | 6125篇 |
2002年 | 3305篇 |
2001年 | 2932篇 |
2000年 | 2001篇 |
1999年 | 3117篇 |
1998年 | 1359篇 |
1997年 | 1171篇 |
1996年 | 1022篇 |
1995年 | 970篇 |
1994年 | 951篇 |
1992年 | 2732篇 |
1991年 | 2622篇 |
1990年 | 2534篇 |
1989年 | 2436篇 |
1988年 | 2303篇 |
1987年 | 2155篇 |
1986年 | 1889篇 |
1985年 | 1939篇 |
1984年 | 1240篇 |
1983年 | 993篇 |
1979年 | 1148篇 |
1978年 | 808篇 |
1975年 | 928篇 |
1974年 | 1045篇 |
1973年 | 1059篇 |
1972年 | 1001篇 |
1971年 | 948篇 |
1970年 | 836篇 |
1969年 | 860篇 |
1967年 | 772篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
101.
Xiao LiWei Xing Shuping Zhuo Jin ZhouFeng Li Shi-Zhang QiaoGao-Qing Lu 《Bioresource technology》2011,102(2):1118-1123
Series of nanoporous carbons are prepared from sunflower seed shell (SSS) by two different strategies and used as electrode material for electrochemical double-layer capacitor (EDLC). The surface area and pore-structure of the nanoporous carbons are characterized intensively using N2 adsorption technique. The results show that the pore-structure of the carbons is closely related to activation temperature and dosage of KOH. Electrochemical measurements show that the carbons made by impregnation-activation process have better capacitive behavior and higher capacitance retention ratio at high drain current than the carbons made by carbonization-activation process, which is due to that there are abundant macroscopic pores and less interior micropore surface in the texture of the former. More importantly, the capacitive performances of these carbons are much better than ordered mesoporous carbons and commercial wood-based active carbon, thus highlighting the success of preparing high performance electrode material for EDLC from SSS. 相似文献
102.
Adult cycling female rats were treated with antisera to highly purified human follitropin and lutropin for eight days. The
effect of this treatment on thein vitro steroidogenic response of the ovarian cells isolated from these rats to follitropin and lutropin has been investigated. Neutralisation
of follitropin did not have significant effect on steroid production in response to lutropin. However, neutralisation of lutropin
resulted in a very significant inhibition of response to both follitropin and lutropin. 相似文献
103.
104.
Protoplasts of Schizosaccharomyces pombe, grown on a rich nutrient medium, were treated with a peptide factor isolated from cultures of the protozoan Tetrahymena pyriformis. The peptide factor is known to inhibit RNA synthesis in Tetrahymena. It has now been shown that the peptide factor also inhibits RNA synthesis in yeast protoplasts without affecting protein synthesis. 相似文献
105.
Peng Wang Ronghua Luo Min Zhang Yaqing Wang Tianzhang Song Tingting Tao Zhongyu Li Lin Jin Hongyi Zheng Wenwen Chen Mengqian Zhao Yongtang Zheng Jianhua Qin 《Cell death & disease》2020,11(12)
COVID-19, caused by SARS-CoV-2, is an acute and rapidly developing pandemic, which leads to a global health crisis. SARS-CoV-2 primarily attacks human alveoli and causes severe lung infection and damage. To better understand the molecular basis of this disease, we sought to characterize the responses of alveolar epithelium and its adjacent microvascular endothelium to viral infection under a co-culture system. SARS-CoV-2 infection caused massive virus replication and dramatic organelles remodeling in alveolar epithelial cells, alone. While, viral infection affected endothelial cells in an indirect manner, which was mediated by infected alveolar epithelium. Proteomics analysis and TEM examinations showed viral infection caused global proteomic modulations and marked ultrastructural changes in both epithelial cells and endothelial cells under the co-culture system. In particular, viral infection elicited global protein changes and structural reorganizations across many sub-cellular compartments in epithelial cells. Among the affected organelles, mitochondrion seems to be a primary target organelle. Besides, according to EM and proteomic results, we identified Daurisoline, a potent autophagy inhibitor, could inhibit virus replication effectively in host cells. Collectively, our study revealed an unrecognized cross-talk between epithelium and endothelium, which contributed to alveolar–capillary injury during SARS-CoV-2 infection. These new findings will expand our understanding of COVID-19 and may also be helpful for targeted drug development.Subject terms: Mechanisms of disease, Viral infection 相似文献
106.
107.
108.
109.
110.