全文获取类型
收费全文 | 504篇 |
免费 | 18篇 |
国内免费 | 1篇 |
专业分类
电工技术 | 12篇 |
化学工业 | 102篇 |
金属工艺 | 10篇 |
机械仪表 | 10篇 |
建筑科学 | 8篇 |
能源动力 | 20篇 |
轻工业 | 55篇 |
水利工程 | 2篇 |
无线电 | 20篇 |
一般工业技术 | 99篇 |
冶金工业 | 123篇 |
原子能技术 | 19篇 |
自动化技术 | 43篇 |
出版年
2021年 | 23篇 |
2020年 | 7篇 |
2019年 | 6篇 |
2018年 | 8篇 |
2017年 | 8篇 |
2016年 | 21篇 |
2015年 | 10篇 |
2014年 | 8篇 |
2013年 | 24篇 |
2012年 | 20篇 |
2011年 | 27篇 |
2010年 | 19篇 |
2009年 | 27篇 |
2008年 | 15篇 |
2007年 | 27篇 |
2006年 | 19篇 |
2005年 | 7篇 |
2004年 | 14篇 |
2003年 | 8篇 |
2002年 | 7篇 |
2001年 | 7篇 |
2000年 | 8篇 |
1999年 | 13篇 |
1998年 | 49篇 |
1997年 | 28篇 |
1996年 | 17篇 |
1995年 | 11篇 |
1994年 | 8篇 |
1993年 | 14篇 |
1992年 | 3篇 |
1991年 | 3篇 |
1990年 | 6篇 |
1989年 | 6篇 |
1988年 | 5篇 |
1987年 | 2篇 |
1986年 | 3篇 |
1985年 | 5篇 |
1984年 | 4篇 |
1983年 | 4篇 |
1982年 | 3篇 |
1980年 | 2篇 |
1978年 | 1篇 |
1977年 | 1篇 |
1976年 | 4篇 |
1975年 | 2篇 |
1974年 | 2篇 |
1971年 | 1篇 |
1970年 | 1篇 |
1968年 | 1篇 |
1957年 | 1篇 |
排序方式: 共有523条查询结果,搜索用时 46 毫秒
521.
522.
For the combinations of a pin of Si3N4 and five kinds of disk, the friction and wear test was carried out in ethanol, and in ethanol containing C60 particles (1 wt%). A topographical analysis was also performed on the micro-asperities of the wear surfaces to estimate the behavior of C60 particles, and the degree of surface damage. As a results, the following facts were found. (1) The addition of C60 particles in ethanol decreased the wear rates of such ceramic disks as Al2O3, SiC and TiC and of the mating Si3N4 pins. (2) The addition of C60 particles decreased the mean coefficient of friction for SiC, Si3N4, and TiC disks. (3) The wear rates of pin and disk depended on the topographies of worn surfaces such as the mean depth of micro-grooves, the mean tip radius of micro-asperities and so on. 相似文献
523.
Kaho Kanno Tomohisa Sakaue Mika Hamaguchi Kenji Namiguchi Daisuke Nanba Jun Aono Mie Kurata Junya Masumoto Shigeki Higashiyama Hironori Izutani 《International journal of molecular sciences》2021,22(19)
The characterization of aortic valve interstitial cells (VICs) cultured under optimal conditions is essential for understanding the molecular mechanisms underlying aortic valve stenosis. Here, we propose 2% hypoxia as an optimum VIC culture condition. Leaflets harvested from patients with aortic valve regurgitation were digested using collagenase and VICs were cultured under the 2% hypoxic condition. A significant increase in VIC growth was observed in 2% hypoxia (hypo-VICs), compared to normoxia (normo-VICs). RNA-sequencing revealed that downregulation of oxidative stress-marker genes (such as superoxide dismutase) and upregulation of cell cycle accelerators (such as cyclins) occurred in hypo-VICs. Accumulation of reactive oxygen species was observed in normo-VICs, indicating that low oxygen tension can avoid oxidative stress with cell-cycle arrest. Further mRNA quantifications revealed significant upregulation of several mesenchymal and hematopoietic progenitor markers, including CD34, in hypo-VICs. The stemness of hypo-VICs was confirmed using osteoblast differentiation assays, indicating that hypoxic culture is beneficial for maintaining growth and stemness, as well as for avoiding senescence via oxidative stress. The availability of hypoxic culture was also demonstrated in the molecular screening using proteomics. Therefore, hypoxic culture can be helpful for the identification of therapeutic targets and the evaluation of VIC molecular functions in vitro. 相似文献