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   49篇
力学   5篇
数学   2篇
物理学   6篇
  2013年   2篇
  2008年   1篇
  2007年   1篇
  2006年   1篇
  2004年   1篇
  2003年   1篇
  2002年   1篇
  2001年   1篇
  2000年   1篇
  1997年   1篇
  1996年   1篇
  1994年   2篇
  1993年   2篇
  1992年   1篇
  1988年   1篇
  1987年   2篇
  1986年   2篇
  1985年   2篇
  1984年   2篇
  1983年   2篇
  1982年   3篇
  1981年   1篇
  1980年   1篇
  1979年   1篇
  1977年   2篇
  1976年   5篇
  1975年   5篇
  1974年   1篇
  1973年   5篇
  1972年   1篇
  1971年   2篇
  1970年   1篇
  1968年   2篇
  1967年   3篇
  1962年   1篇
排序方式: 共有62条查询结果,搜索用时 15 毫秒
1.
The amounts and compositions of the essential oils in the leaves and fruit of Meyer's lemon in the various vegetation periods have been studied. It has been established that as the fruit ripens the amount of essential oils and of monoterpene hydrocarbons in its peel and in the leaves increases.Institute of Plant Biochemistry, Academy of Sciences of the Georgian SSR. Sukhumi Zonal Experimental Station of Essential-Oil Crops. Sukhumi Experimental Station of Subtropical Crops, All-Union Institute of Plant Growing. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 784–787, November–December, 1985.  相似文献   
2.
Information is given on methods of isolating plant pectin substances from various raw-material sources, and the conditions for obtaining high-quality pectin are discussed.  相似文献   
3.
4.
Solasodine (I) has been subjected to a number of transformations. The following compounds have been obtained from it by described procedures: 3-acetoxypregna-5,16-dien-20-one (II), 3-acetoxypregn-5-en-20-ol (III), and 3-acetoxypregn-5-en-20-ol (IV). The oxidation of (III) and (IV), the formation of an oxime, and the reduction of the oxime with sodium in ethanol, followed by Hess methylation, has led to 20-dimethylaminopregn-5-en-3-ol (IX) and to 20-dimethylaminopregn-5-en-3-ol (X). From compounds (IX) and (X), by analogy with (III) and (IV) by their oxidation and the preparation of oximes, which were then reduced and methylated, the following were obtained: 3,20-bisdimethylaminopregnane (XVII) and 3,20-bisdimethylaminopregnane (XVIII), and also quaternary salts of the latter.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 370–374, May–June, 1980.  相似文献   
5.
Six new bisquaternary derivatives of cyclobuxine-D have been obtained, and their biological activities have been studied.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Republic of Uzbekistan, Tashkent, fax (3712) 40 64 75. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 742–744, September–October, 1997.  相似文献   
6.
The solubility polytherm of the ternary system hexamethylenetetramineammonium dihydrogen phosphate-water was studied in a wide temperature range. The concentration and temperature ranges of crystallization of the starting components and a new compound, NH4H2PO4·2(CH2)6N4·8H2O, were determined. The properties and structure of the new compound were studied by X-ray phase, thermal, and IR spectroscopic analyses.  相似文献   
7.
8.
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