全文获取类型
收费全文 | 1038篇 |
免费 | 22篇 |
国内免费 | 1篇 |
专业分类
电工技术 | 104篇 |
综合类 | 1篇 |
化学工业 | 383篇 |
金属工艺 | 22篇 |
机械仪表 | 16篇 |
建筑科学 | 16篇 |
能源动力 | 43篇 |
轻工业 | 110篇 |
水利工程 | 1篇 |
石油天然气 | 1篇 |
无线电 | 56篇 |
一般工业技术 | 163篇 |
冶金工业 | 36篇 |
原子能技术 | 32篇 |
自动化技术 | 77篇 |
出版年
2022年 | 10篇 |
2021年 | 22篇 |
2020年 | 13篇 |
2019年 | 13篇 |
2018年 | 10篇 |
2017年 | 10篇 |
2016年 | 17篇 |
2015年 | 13篇 |
2014年 | 23篇 |
2013年 | 42篇 |
2012年 | 48篇 |
2011年 | 42篇 |
2010年 | 43篇 |
2009年 | 38篇 |
2008年 | 50篇 |
2007年 | 54篇 |
2006年 | 41篇 |
2005年 | 33篇 |
2004年 | 31篇 |
2003年 | 38篇 |
2002年 | 31篇 |
2001年 | 23篇 |
2000年 | 20篇 |
1999年 | 23篇 |
1998年 | 29篇 |
1997年 | 25篇 |
1996年 | 31篇 |
1995年 | 17篇 |
1994年 | 14篇 |
1993年 | 18篇 |
1992年 | 12篇 |
1991年 | 14篇 |
1990年 | 13篇 |
1989年 | 21篇 |
1988年 | 16篇 |
1987年 | 16篇 |
1986年 | 10篇 |
1985年 | 14篇 |
1984年 | 9篇 |
1983年 | 20篇 |
1982年 | 12篇 |
1981年 | 11篇 |
1980年 | 11篇 |
1979年 | 14篇 |
1978年 | 5篇 |
1977年 | 8篇 |
1976年 | 11篇 |
1974年 | 6篇 |
1973年 | 5篇 |
1971年 | 3篇 |
排序方式: 共有1061条查询结果,搜索用时 15 毫秒
1.
2.
3.
4.
The most frequent and important symptoms in primary biliary cirrhosis (PBC) are pruritus and jaundice. In the majority, jaundice appears within one half to two years of onset of pruritus. Xanthoma, bone change and sicca syndrome are often observed. The recent increase in number of asymptomatic PBC is the result of progagation of medical examination. In the biochemical tests, elevation of the biliary enzymes, such as ALP and gamma-GTP, is characteristic, as well as, a high level of serum IgM. Serum bilirubin values are gradually raised along with the clinical course of the disease. Positive antimitochondrial antibody (AMA) is the most valuable immunological finding for the diagnosis of PBC. Anti-pyruvate dehydrogenase complex E2 component E2 has the same significance as AMA. Diagnostic criteria si shown in this paper. 相似文献
5.
Hideaki Katayama Tsutomu Tawa Shinzaburo Ito Masahide Yamamoto Yoshio Wada 《Polymer Bulletin》1992,29(3-4):365-367
Summary The effect of side chain length on intramolecular triplet energy migration of naphthalene containing polymers was investigated by a delayed fluorescence (DF) spectroscopy for the solid solution of the polymers. The degree of triplet energy migration depends strongly on whether the chromophores are directly attached to the main chain or not. 相似文献
6.
Bhupesh C. Roy Motonobu Goto & Tsutomu Hirose 《International Journal of Food Science & Technology》1996,31(2):137-141
Tomato seed oil was extracted with supercritical carbon dioxide in a semibatch-flow extractor within the temperature range 313–343 K and the pressure range 10.8–24.5MPa. The extraction rates increased with pressure, but decreased with temperature increase because of the variation in solvent density and resultant differences in oil solubility. The fatty acid composition of the extracted oil was similar to that of soybean oil. 相似文献
7.
8.
Tsutomu Takeichi Yuki Saito Tarek Agag Hiroyuki Muto Takehiro Kawauchi 《Polymer》2008,49(5):1173-1179
Two series of high-performance polymer alloys were prepared by mixing typical benzoxine monomers, 3-phenyl-3,4-dihydro-2H-1,3-benzoxazine (P-a) or 6,6-(1-methylethyliden)-bis-(3,4-dihydro-3-phenyl-2H-1,3-benzoxazine) (B-a), with a typical bismaleimide, 4,4-bismaleimidodiphenyl methane by various ratios followed by thermal treatment up to 240 °C. DSC and IR of the alloys were examined to follow the curing reaction. These analyses showed that the obtained polymer alloys are AB co-cross-linked polymer networks through the formation of ether linkage between the hydroxyl group of polybenoxazine and the double bond of bismaleimide. Viscoelastic analysis and softening temperature measurement revealed that the polymer alloys have much higher glass transition temperatures than those of each homopolymer. The thermal stability also increased with the increase of bismaleimide content as evidenced by TGA. 相似文献
9.
10.