全文获取类型
收费全文 | 905篇 |
免费 | 33篇 |
国内免费 | 1篇 |
专业分类
电工技术 | 62篇 |
化学工业 | 246篇 |
金属工艺 | 21篇 |
机械仪表 | 21篇 |
建筑科学 | 23篇 |
能源动力 | 71篇 |
轻工业 | 80篇 |
无线电 | 60篇 |
一般工业技术 | 145篇 |
冶金工业 | 54篇 |
原子能技术 | 48篇 |
自动化技术 | 108篇 |
出版年
2024年 | 3篇 |
2023年 | 12篇 |
2022年 | 22篇 |
2021年 | 30篇 |
2020年 | 20篇 |
2019年 | 17篇 |
2018年 | 21篇 |
2017年 | 19篇 |
2016年 | 22篇 |
2015年 | 22篇 |
2014年 | 29篇 |
2013年 | 68篇 |
2012年 | 48篇 |
2011年 | 89篇 |
2010年 | 58篇 |
2009年 | 47篇 |
2008年 | 42篇 |
2007年 | 47篇 |
2006年 | 39篇 |
2005年 | 35篇 |
2004年 | 22篇 |
2003年 | 19篇 |
2002年 | 25篇 |
2001年 | 9篇 |
2000年 | 7篇 |
1999年 | 15篇 |
1998年 | 23篇 |
1997年 | 11篇 |
1996年 | 9篇 |
1995年 | 12篇 |
1994年 | 4篇 |
1993年 | 13篇 |
1992年 | 8篇 |
1991年 | 9篇 |
1990年 | 8篇 |
1989年 | 8篇 |
1988年 | 6篇 |
1987年 | 4篇 |
1986年 | 3篇 |
1985年 | 4篇 |
1984年 | 4篇 |
1983年 | 4篇 |
1982年 | 2篇 |
1980年 | 5篇 |
1979年 | 2篇 |
1978年 | 2篇 |
1976年 | 3篇 |
1974年 | 3篇 |
1969年 | 1篇 |
1967年 | 1篇 |
排序方式: 共有939条查询结果,搜索用时 31 毫秒
101.
Hidenori Yahiro Tatsuya ohuchi Koichi Eguchi Hiromichi Arai 《Journal of Materials Science》1988,23(3):1036-1041
The ionic conduction of oxygen in the ceria-alkaline earth oxide system was investigated as a function of temperature, partial pressure of oxygen and oxide composition, together with its crystal structure, density, and microstructure. Undoped ceria and its solid solution with alkaline earth oxides have a cubic fluorite structure. The ionic conductivity of ceria is greatly enhanced by additions of calcia and strontia, even when they are added in excess of the solubility limit. The conductivities of ceria-calcia and ceria-strontia were much higher than those of calcia-and yttria-stabilized zirconia. Up to the limit of calcia and strontia, the ionic transference number was nearly unity in the temperature range between 600 and 900°C. With an increase in calcia and strontia content, the ionic conductivity was little affected by the presence of a second phase of CaO and SrCeO3. 相似文献
102.
Tatsuya Motoki 《Journal of Computer and System Sciences》1984,29(3):312-329
A result/concept on star height is applied to two problems in the theory of control structures. First, Kosaraju's systems REn of control structures are generalized and it is shown by using Cohen's result on star height that the generalized systems constitute a pathwise hierarchy with respect to their expressive powers. Second, by using a concept on star height, a result of Peterson et al. (Comm. ACM16 (1973), 503–512) that RE∞ is pathwise complete is sharpened. 相似文献
103.
104.
105.
106.
107.
Long-span single-mode fibre transmission experiments at 1.3 ?m have been refined toward higher digit rate and longer fibre span. Error-rate against receiving optical level characteristics showed that optical power penalties at 100 Mbit/s, 1.2 Gbit/s and 1.6 Gbit/s are negligible, even after 30 km, 23 km and 13 km fibre transmission, respectively. 相似文献
108.
Morita N Takamura N Ashizawa K Shimasaki T Yamashita S Okumura Y 《Radiation protection dosimetry》2005,113(3):326-329
To understand the current situation of internal radiation exposure in the population around the Chernobyl Nuclear Power Plant (CNPP), we examined the 137Cs body burden in six residents of Belarus, Ukraine and Russia in 2002 and 2004 using the whole-body counter (WBC) at Nagasaki University (Japan). The data were compared with those of our previous study performed in 1993-1994 using the same method. In 2002 and 2004, peaks of 137Cs were detected in two residents from Gomel, which was heavily contaminated by the CNPP accident, one from Minsk (Belarus) and one from Kiev (Ukraine), but another resident from Minsk showed no 137Cs peaks. The results of the present study suggests that residents around the CNPP are still exposed to chronic 137Cs internal irradiation, probably due to the daily consumption of contaminated domestic foods, but the risk of any disease by the irradiation is quite low. Long-term follow-up of WBC around the CNPP is useful and may contribute to radiation safety regulation together with a reduction of unnecessary radiophobia for the residents. 相似文献
109.
Akio Makishima Michiko Kobayashi Takajiro Shimohira Tatsuya Nagata 《Journal of the American Ceramic Society》1982,65(12):210-C
Formation of aluminosilicate glasses containing oxides of rare-earth elements, e.g. Sc, Ce, Pr, Nd, Eu, Gd, Tb, Dy, Ho, Er, and Yb, was studied by melting at 1550°C and air quenching. The upper limit of the amount of rare-earth oxide which can be incorporated into the aluminosilicate glasses decreases according to the lanthanide contraction. 相似文献
110.