全文获取类型
收费全文 | 1166篇 |
免费 | 2篇 |
专业分类
电工技术 | 6篇 |
化学工业 | 53篇 |
金属工艺 | 11篇 |
机械仪表 | 8篇 |
建筑科学 | 41篇 |
能源动力 | 18篇 |
轻工业 | 46篇 |
水利工程 | 4篇 |
石油天然气 | 1篇 |
无线电 | 31篇 |
一般工业技术 | 76篇 |
冶金工业 | 841篇 |
原子能技术 | 5篇 |
自动化技术 | 27篇 |
出版年
2021年 | 3篇 |
2020年 | 3篇 |
2019年 | 4篇 |
2017年 | 3篇 |
2016年 | 5篇 |
2015年 | 5篇 |
2014年 | 2篇 |
2013年 | 37篇 |
2012年 | 17篇 |
2011年 | 16篇 |
2010年 | 16篇 |
2009年 | 11篇 |
2008年 | 14篇 |
2007年 | 11篇 |
2006年 | 8篇 |
2005年 | 9篇 |
2004年 | 6篇 |
2003年 | 14篇 |
2002年 | 7篇 |
2001年 | 8篇 |
2000年 | 14篇 |
1999年 | 24篇 |
1998年 | 240篇 |
1997年 | 139篇 |
1996年 | 88篇 |
1995年 | 68篇 |
1994年 | 65篇 |
1993年 | 45篇 |
1992年 | 12篇 |
1991年 | 21篇 |
1990年 | 12篇 |
1989年 | 22篇 |
1988年 | 15篇 |
1987年 | 17篇 |
1986年 | 15篇 |
1985年 | 18篇 |
1984年 | 11篇 |
1983年 | 5篇 |
1982年 | 6篇 |
1981年 | 9篇 |
1980年 | 7篇 |
1979年 | 4篇 |
1978年 | 9篇 |
1977年 | 24篇 |
1976年 | 47篇 |
1975年 | 6篇 |
1974年 | 2篇 |
1973年 | 3篇 |
1968年 | 4篇 |
1967年 | 5篇 |
排序方式: 共有1168条查询结果,搜索用时 15 毫秒
1.
Although self-help/mutual-help groups, like Alcoholics Anonymous, are important factors in the recovery of many chemically dependent individuals, the large dropout rates from such groups and the awareness that many who drop out do not return to dependent behavior raises interesting questions about other paths to sustained abstinence and recovery. Current emphasis on treatment outcome studies provides a means for researching factors in both those who recover with and without the assistance of self-help/mutual-help groups. The authors suggest some questions which might be investigated. 相似文献
2.
PB McClelland P Morgan EE Leach J Shelk 《Canadian Metallurgical Quarterly》1997,9(6):403-15; quiz 416-7
Psoralens and sunlight have been used by the Egyptians and Indians for hundreds of years for treating vitiligo. The combination of oral psoralens and artificial ultraviolet A (PUVA) therapy was approved for managing severe psoriasis by the Food and Drug Administration in 1982. Since then, PUVA therapy has been an effective modality for treating many cutaneous conditions (psoriasis, atopic dermatitis, vitiligo, and mycosis fungoides). However, proper knowledge and administration of PUVA therapy are vital to treatment success and reducing side effects. 相似文献
3.
NE Joseph C Fiocchi AD Levine 《Canadian Metallurgical Quarterly》1997,122(4):809-14; discussion 814-6
BACKGROUND: Crohn's disease (CD) and ulcerative colitis (UC) are chronic inflammatory diseases, and their pathogenesis is attributed, in part, to alterations of the mucosal immune system. This study was designed to define the possible contribution of epithelial cells to the activation of lamina propria T lymphocytes (LPTs) in CD and UC. METHODS: LPTs isolated from CD, UC, and control surgical specimens were cocultured with freshly isolated allogeneic or autologous epithelial cells or epithelial cell lines. Resulting T-cell proliferation was evaluated by tritiated thymidine incorporation on day 5. RESULTS: When intestinal epithelial cells were used to stimulate mucosal T-cell proliferation, CD and UC LPTs were less responsive than control LPTs (p < 0.05 and p < 0.03, respectively). This difference between inflamed and control T cells was consistently observed by using a variety of different intestinal epithelial cell types. CONCLUSIONS: CD and UC mucosal T cells are hyporesponsive to activation by intestinal epithelial cells when compared with control LPTs. Elucidating the mechanism underlying the differential activation of CD and UC LPTs may help to better understand the immunopathogenesis of these conditions. 相似文献
4.
M Leach 《Canadian Metallurgical Quarterly》1997,93(22):52-55
We are continually expanding our knowledge of JCA and establishing our understanding on an ever-increasing knowledge base encompassing immunology, immunogenetics, physiology, psychology and sociology. The causes and treatment of this condition are multifactoral and no one discipline can hope to embrace all of them. Nurses, particularly those with rheumatological and/or paediatric expertise, are uniquely placed to provide the link between patient, the family and health care team and thus to coordinate treatment and ensure that care meets the needs of youngsters with JCA and their families. 相似文献
5.
6.
7.
Gerald Leach 《Energy Policy》1991,19(10):918-925
The UK differs from may other industrialized nations in that its carbon dioxide (CO2) emissions from energy use have declined in recent years despite relatively rapid economic growth. In all sectors but transport, substantial reductions have already occurred in the level of carbon emissions per unit of GDP output. At the same time, a number of official and unofficial studies have pointed out that the UK has one of the largest remaining potentials amongst comparable industrialized countries for achieving further CO2 reductions through the implementation of cost-effective energy efficiency and fuel switching measures. This paper discusses past and present patterns of energy use and carbons emissions in the UK. The analysis then examines historical trends in UK energy policy and presents policy options for further reducing the UK's energy-use and carbon emissions in the future. 相似文献
8.
9.
10.
The effects of epithelial removal and cyclooxygenase inhibition on contractions induced by exogenous acetylcholine (ACh) and electrical field stimulation (EFS) were evaluated in horse tracheal strips and bronchial rings. Epithelial removal potentiated the response to ACh but had no influence on the response to EFS. The effect of epithelial removal was not altered by pretreating the tissues with meclofenamate, a cyclooxygenase inhibitor. In trachealis strips, meclofenamate augmented contractions induced by EFS but not by ACh. In bronchial rings, meclofenamate augmented EFS-induced contraction to a greater extent than ACh-induced contraction. These effects of meclofenamate were epithelium-independent. We conclude that horse airway epithelium produces a relaxant factor that is not a prostanoid. Endogenous prostanoids originating from non-epithelial sites inhibit only cholinergic nerves in the trachea but both parasympathetic nerves and smooth muscle in the bronchi. 相似文献