全文获取类型
收费全文 | 757篇 |
免费 | 5篇 |
国内免费 | 3篇 |
专业分类
电工技术 | 7篇 |
化学工业 | 59篇 |
金属工艺 | 1篇 |
机械仪表 | 1篇 |
建筑科学 | 5篇 |
能源动力 | 2篇 |
轻工业 | 25篇 |
无线电 | 7篇 |
一般工业技术 | 54篇 |
冶金工业 | 588篇 |
原子能技术 | 3篇 |
自动化技术 | 13篇 |
出版年
2022年 | 5篇 |
2021年 | 4篇 |
2020年 | 10篇 |
2019年 | 2篇 |
2018年 | 3篇 |
2017年 | 2篇 |
2016年 | 3篇 |
2015年 | 1篇 |
2014年 | 5篇 |
2013年 | 9篇 |
2012年 | 6篇 |
2011年 | 11篇 |
2010年 | 7篇 |
2009年 | 6篇 |
2008年 | 5篇 |
2007年 | 5篇 |
2006年 | 8篇 |
2005年 | 5篇 |
2004年 | 8篇 |
2003年 | 6篇 |
2001年 | 1篇 |
2000年 | 3篇 |
1999年 | 9篇 |
1998年 | 150篇 |
1997年 | 97篇 |
1996年 | 62篇 |
1995年 | 48篇 |
1994年 | 33篇 |
1993年 | 43篇 |
1992年 | 6篇 |
1991年 | 14篇 |
1990年 | 8篇 |
1989年 | 14篇 |
1988年 | 9篇 |
1987年 | 10篇 |
1986年 | 16篇 |
1985年 | 13篇 |
1984年 | 4篇 |
1983年 | 2篇 |
1982年 | 3篇 |
1981年 | 7篇 |
1980年 | 6篇 |
1979年 | 1篇 |
1978年 | 8篇 |
1977年 | 19篇 |
1976年 | 60篇 |
1975年 | 3篇 |
1973年 | 2篇 |
1964年 | 1篇 |
1955年 | 1篇 |
排序方式: 共有765条查询结果,搜索用时 15 毫秒
11.
12.
The tail-flick (TF) technique was used to assess the antinociceptive properties of nifedipine (NIF) given intraperitoneally (i.p.). First, the most suitable intensity of the noxious stimulus (temperature of the bulb) has been ascertained and used in the main study. Male Sprague-Dawley rats received NIF, dissolved in dimethyl sulfoxide (DMSO) at the doses of 0.0, 0.5, 2, 5, 10 and 15 mg/kg, or control with no injection. For the main study, the noxious stimulus was limited to 15 sec (cut-off time) and TF latencies were recorded up to 120 min. The antinociceptive response was expressed as the area under the curve for each rat and analyzed by one-way ANOVA. The antinociceptive response to the lower doses of NIF (0.5 and 2 mg/kg) did not differ from control (no injection) and DMSO alone. Significance was found at 5, 10 and 15 mg NIF with no difference among the doses. However, there was an increasing tendency of the mean values from 0.5 to 15 mg NIF resulting in a positive correlation. The correlation coefficient was 0.32483 (p = 0.015) and regression equation Y = (19.37) x dose + 1320. Our data suggest that spinal mechanisms are involved in NIF-induced antinociception. 相似文献
13.
14.
V.K. Raina K. Sasidharan Samiran Sengupta Tej Singh 《Nuclear Engineering and Design》2006,236(7-8):770-783
At present Dhruva and Cirus reactors provide the majority of research reactor based facilities to cater to the various needs of a vast pool of researchers in the field of material sciences, physics, chemistry, bio sciences, research & development work for nuclear power plants and production of radio isotopes. With a view to further consolidate and expand the scope of research and development in nuclear and allied sciences, a new 20 MWt multi purpose research reactor is being designed. This paper describes some of the design features and safety aspects of this reactor. 相似文献
15.
16.
Using total quality management principles within a shared governance framework, this case study discusses how to design and implement a plan to achieve independent nursing practice when an employee has unique needs. This experience demonstrates the importance of looking at root causes, separating ability and compliance issues, using all available resources creatively, and planning for success. 相似文献
17.
18.
PJ Johnson SC Tyagi LC Katwa VK Ganjam LA Moore JM Kreeger NT Messer 《Canadian Metallurgical Quarterly》1998,142(15):392-396
Samples of connective tissue obtained from the hoof of six laminitic and eight non-laminitic adult horses were analysed zymographically to investigate whether connective tissue matrix metalloproteinases are activated or induced during laminitis. The activity or matrix metalloproteinases was substantially greater in the tissues from the laminitic horses than in the tissues from the non-laminitic horses. A comparison of the collagenolytic activity in the laminitic and control tissues showed that collagenolytic activities corresponding to the 92 kDa (P < 0.001), 72 kDa (P < 0.01) and 66 kDa (P < 0.01) bands were induced in the laminitic tissues. 相似文献
19.
A cigarette which heats rather than burns tobacco (Premier) was introduced in 1988, but was unacceptable due to unpleasant taste and low nicotine intake. We examined availability of nicotine from a new version (Eclipse), in the same four subjects as our earlier Premier study. Average blood nicotine boosts of 23.7 and 17.8 ng/ml were obtained from smoking a first and second Eclipse. This substantially exceeds intake from Premier (boost 13 ng/ml) and that obtained by heavy smokers from conventional brands (boost 12-15 ng/ml). Eclipse (or similar product) may be the best option for averting Peto's dire warnings of rising millions of annual smoking deaths in the 2020s, and its potential for large-scale, long-term switching warrants further study. 相似文献
20.
VK Boppana 《Canadian Metallurgical Quarterly》1995,692(1-2):195-202
A highly sensitive and selective high-performance liquid chromatographic method was developed for the determination of granisetron and its active metabolite, 7-hydroxygranisetron (7OH-G) in human plasma. Granisetron is a selective 5-hydroxytryptamine receptor antagonist used in the treatment of cytotoxic drug-induced emesis. The method involves isolation of granisetron, 7OH-G and the internal standards from plasma by solid-phase extraction prior to reversed-phase ion-pair chromatographic separation on an octyl silica column with subsequent quantification of analytes simultaneously either with electrochemical (7OH-G) or fluorescence (granisetron) detectors which are placed in series. The recovery of granisetron and 7OH-G from human plasma was quantitative. Using 1 ml of plasma, the limits of quantification for granisetron and 7OH-G were 0.1 and 0.25 ng/ml, respectively. Linear responses in analyte/internal standard peak-area ratios were observed for analyte concentrations ranging from 0.1 to 50 ng/ml plasma. Precision and accuracy were within 13% across the calibration range for both granisetron and 7OH-G. The method was sufficiently sensitive, accurate and precise to support pharmacokinetic studies for granisetron and 7OH-G, in both normal and patient populations. 相似文献