全文获取类型
收费全文 | 9117篇 |
免费 | 582篇 |
国内免费 | 11篇 |
专业分类
电工技术 | 100篇 |
综合类 | 18篇 |
化学工业 | 2281篇 |
金属工艺 | 196篇 |
机械仪表 | 186篇 |
建筑科学 | 371篇 |
矿业工程 | 30篇 |
能源动力 | 307篇 |
轻工业 | 868篇 |
水利工程 | 111篇 |
石油天然气 | 23篇 |
无线电 | 567篇 |
一般工业技术 | 1980篇 |
冶金工业 | 1240篇 |
原子能技术 | 31篇 |
自动化技术 | 1401篇 |
出版年
2024年 | 12篇 |
2023年 | 71篇 |
2022年 | 157篇 |
2021年 | 291篇 |
2020年 | 204篇 |
2019年 | 236篇 |
2018年 | 265篇 |
2017年 | 236篇 |
2016年 | 293篇 |
2015年 | 234篇 |
2014年 | 368篇 |
2013年 | 674篇 |
2012年 | 560篇 |
2011年 | 780篇 |
2010年 | 548篇 |
2009年 | 486篇 |
2008年 | 546篇 |
2007年 | 490篇 |
2006年 | 422篇 |
2005年 | 369篇 |
2004年 | 310篇 |
2003年 | 283篇 |
2002年 | 264篇 |
2001年 | 128篇 |
2000年 | 122篇 |
1999年 | 116篇 |
1998年 | 114篇 |
1997年 | 105篇 |
1996年 | 89篇 |
1995年 | 99篇 |
1994年 | 90篇 |
1993年 | 66篇 |
1992年 | 75篇 |
1991年 | 34篇 |
1990年 | 34篇 |
1989年 | 46篇 |
1988年 | 44篇 |
1987年 | 43篇 |
1986年 | 37篇 |
1985年 | 56篇 |
1984年 | 46篇 |
1983年 | 43篇 |
1982年 | 44篇 |
1981年 | 27篇 |
1980年 | 30篇 |
1979年 | 21篇 |
1978年 | 21篇 |
1977年 | 18篇 |
1976年 | 18篇 |
1975年 | 12篇 |
排序方式: 共有9710条查询结果,搜索用时 15 毫秒
1.
2.
3.
Carolyn A. Grimley Stephen Funni Christopher Green Elizabeth C. Dickey 《Journal of the European Ceramic Society》2021,41(4):2807-2817
In flash sintering experiments, the thermal history of the sample is key to understanding the mechanisms underlying densification rate and final properties. By combining robust temperature measurements with current-ramp-rate control, this study examined the effects of the thermal profile on the flash sintering of yttria-stabilized zirconia, with experiments ranging from a few seconds to several hours. The final density was maximized at slower heating rates, although processes slower than a certain threshold led to grain growth. The amount of grain growth observed was comparable to a similar conventional thermal process. The bulk electrical conductivity correlated with the maximum temperature and cooling rate. The only property that exhibited behavior that could not be attributed to solely the thermal profile was the grain boundary conductivity, which was consistently higher than conventional in flash sintered samples. These results suggest that, during flash sintering, athermal electric field effects are relegated to the grain boundary. 相似文献
4.
5.
6.
Roberto Zefferino Claudia Piccoli Sante Di Gioia Nazzareno Capitanio Massimo Conese 《International journal of molecular sciences》2021,22(5)
Connexin- and pannexin (Panx)-formed hemichannels (HCs) and gap junctions (GJs) operate an interaction with the extracellular matrix and GJ intercellular communication (GJIC), and on account of this they are involved in cancer onset and progression towards invasiveness and metastatization. When we deal with cancer, it is not correct to omit the immune system, as well as neglecting its role in resisting or succumbing to formation and progression of incipient neoplasia until the formation of micrometastasis, nevertheless what really occurs in the tumor microenvironment (TME), which are the main players and which are the tumor or body allies, is still unclear. The goal of this article is to discuss how the pivotal players act, which can enhance or contrast cancer progression during two important process: “Activating Invasion and Metastasis” and the “Avoiding Immune Destruction”, with a particular emphasis on the interplay among GJIC, Panx-HCs, and the purinergic system in the TME without disregarding the inflammasome and cytokines thereof derived. In particular, the complex and contrasting roles of Panx1/P2X7R signalosome in tumor facilitation and/or inhibition is discussed in regard to the early/late phases of the carcinogenesis. Finally, considering this complex interplay in the TME between cancer cells, stromal cells, immune cells, and focusing on their means of communication, we should be capable of revealing harmful messages that help the cancer growth and transform them in body allies, thus designing novel therapeutic strategies to fight cancer in a personalized manner. 相似文献
7.
Chitosan (CHT) is a non-toxic and inexpensive compound obtained by deacetylation of chitin, the main component of the exoskeleton of arthropods as well as of the cell walls of many fungi. In agriculture CHT is used to control numerous diseases on various horticultural commodities but, although different mechanisms have been proposed, the exact mode of action of CHT is still unknown. In sycamore (Acer pseudoplatanus L.) cultured cells, CHT induces a set of defense/stress responses that includes production of H2O2 and nitric oxide (NO). We investigated the possible signaling role of these reactive molecules in some CHT-induced responses by means of inhibitors of production and/or scavengers. The results show that both reactive nitrogen and oxygen species are not only a mere symptom of stress conditions but are involved in the responses induced by CHT in sycamore cells. In particular, NO appears to be involved in a cell death form induced by CHT that shows apoptotic features like DNA fragmentation, increase in caspase-3-like activity and release of cytochrome c from the mitochondrion. On the contrary, reactive oxygen species (ROS) appear involved in a cell death form induced by CHT that does not show these apoptotic features but presents increase in lipid peroxidation. 相似文献
8.
9.