全文获取类型
收费全文 | 581篇 |
免费 | 1篇 |
专业分类
电工技术 | 4篇 |
综合类 | 1篇 |
化学工业 | 8篇 |
金属工艺 | 2篇 |
建筑科学 | 4篇 |
轻工业 | 4篇 |
无线电 | 14篇 |
冶金工业 | 529篇 |
自动化技术 | 16篇 |
出版年
2021年 | 1篇 |
2019年 | 1篇 |
2018年 | 1篇 |
2015年 | 1篇 |
2014年 | 2篇 |
2013年 | 5篇 |
2011年 | 1篇 |
2010年 | 2篇 |
2009年 | 3篇 |
2007年 | 2篇 |
2006年 | 1篇 |
2005年 | 3篇 |
2004年 | 2篇 |
2003年 | 2篇 |
2002年 | 2篇 |
2001年 | 2篇 |
2000年 | 1篇 |
1999年 | 19篇 |
1998年 | 141篇 |
1997年 | 89篇 |
1996年 | 53篇 |
1995年 | 31篇 |
1994年 | 28篇 |
1993年 | 31篇 |
1992年 | 4篇 |
1991年 | 10篇 |
1990年 | 13篇 |
1989年 | 9篇 |
1988年 | 11篇 |
1987年 | 8篇 |
1986年 | 10篇 |
1985年 | 5篇 |
1984年 | 1篇 |
1983年 | 2篇 |
1982年 | 5篇 |
1981年 | 7篇 |
1980年 | 7篇 |
1978年 | 1篇 |
1977年 | 20篇 |
1976年 | 40篇 |
1975年 | 1篇 |
1966年 | 2篇 |
1965年 | 1篇 |
1964年 | 1篇 |
排序方式: 共有582条查询结果,搜索用时 46 毫秒
101.
102.
The revised Piper Fatigue Scale: psychometric evaluation in women with breast cancer 总被引:4,自引:0,他引:4
BF Piper SL Dibble MJ Dodd MC Weiss RE Slaughter SM Paul 《Canadian Metallurgical Quarterly》1998,25(4):677-684
The population of retinal ganglion cells which project ipsilaterally in the brain was examined in the fat-tailed dunnart, Sminthopsis crassicaudata, following injection of horseradish peroxidase into one optic tract. Retinae were examined as wholemounts and optic nerves as serial sections. In addition, visual fields were measured ophthalmoscopically. Ipsilaterally projecting ganglion cells were located temporal to a line which ran vertically through the middle of the area centralis and extended medially to define a ventrolateral crescent. Temporal to the naso-temporal division, a mean of 77% of ganglion cells projected ipsilaterally; these cells represented 20% of the total ganglion cell population. The magnitude and retinal location of the ipsilateral projection correlated with the extensive binocular field which measured 180 deg in the vertical (from 20 deg below the horizontal axis to 70 deg beyond the zenith) and 140 deg in horizontal meridian. Ipsilaterally projecting axons were restricted to the lateral third of the optic nerve along its length, sharing territory with contralaterally projecting axons. 相似文献
103.
104.
105.
Propranolol serum levels during twenty-four hours 总被引:1,自引:0,他引:1
E Vervloet BF Pluym J Cilissen K K?hlen FW Merkus 《Canadian Metallurgical Quarterly》1977,22(6):853-857
Propranolol serum levels during a 24-hr period were determined every 2 hr in 9 hospitalized patients with angina pectoris after oral administration of 40 mg of propranolol 3 times a day. After the first, second, and third tablets the mean maximum serum propranolol concentrations averaged 118 +/- 71 ng/ml, 134 +/- 97 ng/ml, and 118 +/- 94 ng/ml and the mean minimum concentrations averaged 21 +/- 18 ng/ml, 45 +/- 25 ng/ml, and 54 +/- 34 ng/ml (+/-SD), respectively. These data show a very wide inter- and intraindividual variation in serum propranolol levels. No relationship was found between serum level and blood pressure or dose (related to body weight). 相似文献
106.
1. A spectrophotometric assay using rho-iodo-nitro-triphenyl tetrazolium chloride as the indicator was developed for splenic tissue in the goldfish Carassius auratus. 2. This technique permits a rapid test for the activities of the enzymes lactic dehydrogenase, malic dehydrogenase, and alpha-glycerophosphate dehydrogenase which are indicative of the relative activities of various metabolic pathways. 相似文献
107.
In order to gain further information about the effect of stretch on the urinary bladder of the toad, transepithelial movement of radioactive sucrose, chloride, and urea was measured across bladder sacs during acute changes in the internal volume. Short-circuit current (SCC) and total tissue conductance (Kt) were also measured in each experiment. It was found that sudden large increases or smaller graded increases in volume resulted in a consistent fall in the tracer permeability (P*) of all three isotopes. However, this fall was due entirely to the larger area term in the calculation of P* rather than any real change in isotope movement. When total diffusion (TD) of each isotope was calculated by a method that eliminated the changes in surface area, it was apparent that stretch produced no significant effects on the transepithelial movement of any of these three molecules. Large stretch also resulted in parallel increases in SCC and Kt in most bladders. We conclude from these observations that the intercellular pathway for sucrose and chloride and the transcellular pathway for urea are unaltered by degrees of stretch that enhance SCC and sodium transport. By inference, the observed increases in Kt appear to represent changes in specific active pathway conductance (Ka), and may relate importantly to the changes in sodium transport. 相似文献
108.
The likelihood of off-normal atmospheric releases from a municipal incinerator burning a combination of municipal solid waste and PCB-contaminated landfill material is evaluated. Fault-tree analysis identifies potential system failures in the combustion and air-pollution control systems 相似文献
109.
110.
To examine the effect of hypophysectomy on intestinal calcium absorption, studies were performed on immature rats 7, 14, and 21 days after hypophysectomy. Duodenal calcium transport was measured in vitro utilizing everted gut sacs and in vivo by a luminal perfusion technique. Hypophysectomy produced no differences in the ability of everted gut sacs to transport calcium. Similarly, when in vivo transport data were expressed on the basis of intestinal length, no significant differences were noted. However, when transport data were expressed on the basis of mucosal weight, increases in absorption and lumen-to-plasma fluxes were apparent in hypophysectomized animals. No differences were seen in plasma-to-lumen fluxes. The results indicate that when the transport data are corrected for mass of intestinal mucosa, the duodenum from hypophysectomized animals absorbs calcium more avidly due to an increase in lumen-to-plasma flux. 相似文献