全文获取类型
收费全文 | 728篇 |
免费 | 1篇 |
专业分类
化学工业 | 2篇 |
建筑科学 | 1篇 |
矿业工程 | 1篇 |
能源动力 | 6篇 |
无线电 | 5篇 |
一般工业技术 | 1篇 |
冶金工业 | 656篇 |
原子能技术 | 2篇 |
自动化技术 | 55篇 |
出版年
2019年 | 1篇 |
2017年 | 1篇 |
2014年 | 2篇 |
2013年 | 3篇 |
2012年 | 1篇 |
2011年 | 1篇 |
2009年 | 3篇 |
2008年 | 1篇 |
2007年 | 1篇 |
2006年 | 2篇 |
2005年 | 1篇 |
2004年 | 2篇 |
2003年 | 1篇 |
2002年 | 2篇 |
2001年 | 5篇 |
2000年 | 1篇 |
1999年 | 26篇 |
1998年 | 194篇 |
1997年 | 109篇 |
1996年 | 80篇 |
1995年 | 50篇 |
1994年 | 28篇 |
1993年 | 53篇 |
1992年 | 19篇 |
1991年 | 11篇 |
1990年 | 8篇 |
1989年 | 12篇 |
1988年 | 7篇 |
1987年 | 6篇 |
1986年 | 8篇 |
1985年 | 10篇 |
1984年 | 1篇 |
1983年 | 1篇 |
1982年 | 3篇 |
1981年 | 6篇 |
1980年 | 7篇 |
1979年 | 1篇 |
1978年 | 1篇 |
1977年 | 19篇 |
1976年 | 37篇 |
1975年 | 2篇 |
1974年 | 1篇 |
1955年 | 1篇 |
排序方式: 共有729条查询结果,搜索用时 0 毫秒
31.
32.
G Velikova RE Banks A Gearing I Hemingway MA Forbes SR Preston NR Hall M Jones J Wyatt K Miller U Ward J Al-Maskatti SM Singh PJ Finan NS Ambrose JN Primrose PJ Selby 《Canadian Metallurgical Quarterly》1998,77(11):1857-1863
The concentrations of the soluble adhesion molecules E-cadherin, E-selectin, intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) were investigated in 48 patients with colorectal cancer before treatment, and their relation to clinical, histological and routine laboratory parameters was examined. Data were collected on tumour stage at presentation, presence and sites of metastatic disease, tumour pathology and results of routine laboratory tests. Serum concentrations of ICAM-1 and VCAM-1 were significantly elevated in the patients with colorectal cancer in comparison with a group of healthy subjects (P < 0.00001). Levels of circulating ICAM-1 and VCAM-1 were increased both in patients with local and those with metastatic disease. Although elevated in some patients soluble E-cadherin and E-selectin concentrations were not significantly elevated compared with the control group (P = 0.71 and P = 0.052 respectively). The levels of circulating ICAM-1 were significantly correlated with those of VCAM-1 and E-selectin. A correlation was also found between the serum concentrations of E-selectin and ICAM-1 and alkaline phosphatase, total white cell count and platelet count. VCAM-1 was positively correlated with age and negatively with degree of tumour differentiation and haemoglobin concentration. The biological implications and possible clinical relevance of these findings are discussed. 相似文献
33.
34.
35.
Presented is a model that integrates three data types (numbers, intervals, and linguistic assessments). Data of these three types come from a variety of sensors. One objective of sensor-fusion models is to provide a common framework for data integration, processing, and interpretation. That is what our model does. We use a small set of artificial data to illustrate how problems as diverse as feature analysis, clustering, cluster validity, and prototype classifier design can all be formulated and attacked with standard methods once the data are converted to the generalized coordinates of our model. The effects of reparameterization on computational outputs are discussed. Numerical examples illustrate that the proposed model affords a natural way to approach problems which involve mixed data types 相似文献
36.
37.
NR Liley 《Canadian Metallurgical Quarterly》1976,54(9):1409-1422
The role of estrogen and progesterone in the regulation of reproductive behavior was studied in female ring doves (Streptopelia risoria) under long vs. short photoperiods. The doves held under long (16 hours/day) or short (8 hours/day) photoperiods were treated for 15 days with saline, estrogen, or progesterone, alone or in combination. 7 days after the start of hormone therapy, the doves were placed with reproductively active males for 4 hours/day for 9 days. No difference was seen in egg-laying, courtship or nest-building by control birds under the 2 photo regimes. Ovarian follicles remained small in all doves receiving hormone treatment. Oviducts of doves receiving progesterone alone remained small in the short-photoperiod group but at long photoperiods the oviducts became enlarged. Estrogen stimulated oviduct growth at both photoperiods wheras the combined hormone treatment resulted in greater oviduct development than estrogen alone (p less than .02). Female soliciting and nest-building activity remained low in progesterone-treated doves under short photoperiod but increased rapidly under long photoperiod. Doves treated with estrogen and estrogen plus progesterone performed considerable soliciting and nest-building. No marked tendency was seen for doves under long-photoperiod conditions to be more active in nest-oriented behavior. Copulatory behavior by the female occurred infrequently in all hormone-treated doves. 相似文献
38.
39.
40.