首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   62篇
  免费   0篇
化学   56篇
力学   1篇
数学   2篇
物理学   3篇
  2020年   2篇
  2019年   1篇
  2017年   1篇
  2013年   1篇
  2012年   1篇
  2011年   3篇
  2010年   1篇
  2007年   2篇
  2006年   3篇
  2005年   3篇
  2004年   3篇
  2003年   1篇
  2002年   1篇
  1999年   1篇
  1998年   1篇
  1994年   1篇
  1992年   1篇
  1991年   4篇
  1990年   5篇
  1989年   2篇
  1988年   3篇
  1987年   5篇
  1986年   2篇
  1985年   4篇
  1984年   3篇
  1981年   2篇
  1980年   1篇
  1979年   2篇
  1978年   1篇
  1977年   1篇
排序方式: 共有62条查询结果,搜索用时 31 毫秒
1.
2.
3.
4.
The diethylstilbestrol-related compounds 3,3'-dihydroxy-alpha, beta-diethyldiphenylethane (I), diethylstilbestrol (II) and hexestrol (III) showed hypotensive effects on spontaneously hypertensive rats (SHR) and antifungal activities against all Fusarium oxysporum sp. tested. As previously reported, I had strong hypotensive action on normotensive rats at the dose of 10 mg/kg, while II and III showed weak hypotensive effects on these rats at the same dose. In this work, all three compounds also had hypotensive actions on SHR at the same dose. I showed the strongest hypotensive effect (-80.0 +/- 5.0 mmHg, 10 mg/kg, i.v.) on both SHR and normotensive rats. The three compounds also had antifungal activities against five kinds of Fusarium oxysporum sp. tested. Especially, II strongly inhibited the growth of Fusarium oxysporum f. sp. raphani IFO-9972 (minimum inhibitory concentration (MIC): 1.0 micrograms/ml).  相似文献   
5.
3,3',4,5'-Tetrahydroxystilbene (I) and 3,3',4,5'-tetrahydroxybibenzyl (II), isolated from the heartwood of Cassia garrettiana Craib (Leguminosae), showed inhibitory effects on antigen-induced histamine release from rat peritoneal mast cells in vitro. The inhibitory effect of I (IC50 = 30.2 microM) was much stronger than that of II (greater than 100 microM). Compound II, as well as I (IC50 = 7.3 microM) reported previously, also inhibited the histamine release from human peripheral basophils induced by anti-immunoglobulin E (IgE) in vitro, and its IC50-value was 68.0 microM. These results suggest that the trans-olefin structure in the molecule may be necessary for I to have an inhibitory effect on histamine release. Considering that disodium cromoglycate did not show any significant inhibitory effect on anti-IgE-induced histamine release from human basophils, the strong inhibitory effects of I in both tests are of considerable interest.  相似文献   
6.
7.
In the presence of a cationic Ru catalyst, 1,6-diynes bearing a terminal styryl moiety underwent [2+2+2] cyclization to produce dehydrobiphenylenes fused with a five-membered ring. Although the cycloadducts were unstable toward purification, their one-pot iodine-mediated ring expansion successfully afforded unprecedented bridged ketone products containing a benzo-fused bicyclo[3.2.1] framework.  相似文献   
8.
Host lattice Ba3Si5O13−δNδ oxonitridosilicates have been synthesized by the traditional solid state reaction method. The lattice structure is based on layers of vertex-linked SiO4 tetrahedrons and Ba2+ ions, where each Ba2+ ion is coordinated by eight oxygen atoms forming distorted square antiprisms. Under an excitation wavelength of 365 nm, Ba3Si5O13−δNδ:Eu2+ and Ba3Si5O13−δNδ:Eu2+,Ce3+ show broad emission bands from about 400-620 nm, with maxima at about 480 nm and half-peak width of around 130 nm. The emission intensity is strongly enhanced by co-doping Ce3+ ions into the Ba3Si5O13−δNδ:Eu2+ phosphor, which could be explained by energy transfer. The excitation band from the near UV to the blue light region confirms the possibility that Ba3Si5O13−δNδ:Eu2+, Ce3+ could be used as a phosphor for white LEDs.  相似文献   
9.
10.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号