全文获取类型
收费全文 | 2849篇 |
免费 | 7篇 |
专业分类
电工技术 | 9篇 |
综合类 | 16篇 |
化学工业 | 38篇 |
金属工艺 | 3篇 |
机械仪表 | 15篇 |
建筑科学 | 17篇 |
矿业工程 | 9篇 |
能源动力 | 2篇 |
轻工业 | 9篇 |
水利工程 | 5篇 |
石油天然气 | 2篇 |
武器工业 | 2篇 |
无线电 | 6篇 |
一般工业技术 | 34篇 |
冶金工业 | 2670篇 |
原子能技术 | 2篇 |
自动化技术 | 17篇 |
出版年
2024年 | 1篇 |
2018年 | 1篇 |
2016年 | 2篇 |
2015年 | 1篇 |
2014年 | 5篇 |
2013年 | 4篇 |
2012年 | 8篇 |
2011年 | 20篇 |
2010年 | 10篇 |
2009年 | 13篇 |
2008年 | 22篇 |
2007年 | 47篇 |
2006年 | 11篇 |
2005年 | 12篇 |
2004年 | 2篇 |
2003年 | 12篇 |
2002年 | 7篇 |
2001年 | 2篇 |
2000年 | 4篇 |
1999年 | 76篇 |
1998年 | 778篇 |
1997年 | 453篇 |
1996年 | 256篇 |
1995年 | 165篇 |
1994年 | 150篇 |
1993年 | 172篇 |
1992年 | 13篇 |
1991年 | 45篇 |
1990年 | 35篇 |
1989年 | 33篇 |
1988年 | 34篇 |
1987年 | 29篇 |
1986年 | 37篇 |
1985年 | 24篇 |
1983年 | 9篇 |
1982年 | 13篇 |
1981年 | 28篇 |
1980年 | 25篇 |
1979年 | 2篇 |
1978年 | 15篇 |
1977年 | 97篇 |
1976年 | 173篇 |
1975年 | 7篇 |
1959年 | 1篇 |
1955年 | 2篇 |
排序方式: 共有2856条查询结果,搜索用时 343 毫秒
971.
Workers engaged into deep mining are subjected to occupational factors intensity of which is significantly higher than the allowable. Changing the mining enterprises involves deterioration of the working environment, increase in occupational morbidity. Features of the working environment, parameters of main occupational entities, recent social instability at mining enterprises necessitate further investigations on the problem. 相似文献
972.
DR Nyholt JL Dawkins PJ Brimage PJ Goadsby GA Nicholson LR Griffiths 《Canadian Metallurgical Quarterly》1998,7(3):459-463
Although in cord blood (CB) transplantation graft-versus-host disease (GVHD) is reported to be less severe, GVHD may occur even in patients with HLA-identical sibling donors. This result shows that HLA typing can not entirely predict GVHD. The standard MLR with CB cells was either normal or slightly reduced compared with adult peripheral blood (PB) cells. We used two manipulations to increase the responses of CB cells to allo-antigens. The first was to treat the stimulator cells with cytokines, and the second to amplify weak proliferative responses by adding exogenous cytokines to MLR cultures (modified MLR). The stimulator cells were treated with both interferon-gamma (IFN-gamma) and IL-4. The responder cells were treated with both IL-2 and tumour necrosis factor-alpha (TNF-alpha). It is still to be determined whether or not this cytokine-enhanced MLR could be a possible predictor of GVHD. However, using these cytokines, 90% of CB could recognize allo-antigens, even if the standard MLR was negative. 相似文献
973.
The role of epidemiologists in eradicability of poverty 总被引:1,自引:0,他引:1
GA Kaplan 《Canadian Metallurgical Quarterly》1998,352(9140):1627-1628
974.
975.
976.
Because of the anatomical features associated with situs inversus, technical difficulties will be encountered during orthotopic liver transplantation. This report describes the case of a patient with situs inversus totalis and end-stage liver disease from biliary atresia who was treated by segmental orthotopic liver transplantation. The segmental graft was safely placed in the left subphrenic space, and a suitable orientation was obtained for anastomoses of the hilar vessels. Chronic rejection necessitated retransplantation, by the same method, 19 months later. This technique has potential advantages in coping with anatomical obstacles encountered in patients with situs inversus. 相似文献
977.
978.
979.
980.