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   39篇
  免费   0篇
化学   32篇
数学   3篇
物理学   4篇
  2022年   1篇
  2019年   2篇
  2018年   4篇
  2017年   3篇
  2016年   3篇
  2015年   1篇
  2014年   1篇
  2013年   2篇
  2010年   1篇
  2009年   1篇
  2008年   3篇
  2007年   2篇
  2006年   2篇
  2005年   1篇
  2002年   2篇
  2001年   2篇
  1998年   1篇
  1986年   1篇
  1985年   3篇
  1980年   1篇
  1979年   1篇
  1973年   1篇
排序方式: 共有39条查询结果,搜索用时 15 毫秒
1.
2.
The electrophilic chlorine addition to 3-substituted 1,5-dinitro-3-azabicyclo[3.3.1]-non-6-enes in the tetrachloromethane is accompanied at an intramolecular 3,7-cyclization giving 6-chloro-3-R-1,5-dinitro-3-azoniatricyclo[3.3.1.03,7]nonane chlorides. The reaction of the tricyclic quaternary ammonium salts with sodium methoxide leads to the formation of dealkylated and dehydrohalogenated products, 3-substituted 8-chloro-1,5-dinitro-3-azabicyclo[3.3.1]non-6-enes, bicyclic products with a halogen atom in an allyl position with respect to the double bond.  相似文献   
3.
4.
The reduction of CO by the nitrogen-fixing systems Ti(OH)3−Mo(OH)3 and MgTi2O4−Mo(OH)3 was studied in aqueous and water-methanol media; in the latter,14CO was used as the reagent. The main reaction product is methanol, whose yield in the H2O−MeOH−KOH mixture is almost an, order of magnitude higher than that in an aqueous alkaline solution. The data obtained were compared to those for the reduction of N2 Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 10 pp. 2081–2083, October, 1998.  相似文献   
5.
The specific features of the synthesis and the physicochemical properties of new nanocomposite polymer electrolytes (NPE) based on poly(ethylene glycol) diacrylate, a liquid electrolyte, and silicon dioxide were studied. The kinetics of polymerization of the system in question were studied by isothermal calorimetry and the optimal conditions for the hardening of the NPE were selected. The dependence of the conductivity of the electrolyte samples on the amount of SiO2 nanopowder introduced, the presence of preliminary ultrasonic treatment of the nanocomposite mixture before the synthesis, and the storage duration of the samples was studied using the electrochemical impedance method. The maximum conductivity (4.3?10–3 S cm–1 at 20 °C) was observed for samples without preliminary treatment with the introduction of 6 wt.% of SiO2 and for the samples after ultrasonic treatment with 8 wt.% of SiO2. The electrolyte films with the optimal SiO2 content of 4 wt.% maintained their properties for 24 months.  相似文献   
6.
7.
Dependence of gassing upon decomposition of 1 M LiClO4 electrolyte in γ-butyrolactone (γBL) with various contents of water (0.008 and 0.2% w/w) at a lithium electrode on the current density of charging was studied. Quantum chemical modeling of γBL interaction with lithium surface was performed. The initial stage of γBL decomposition is the formation of a surface organolithium compound, which is hydrolyzed in the subsequent reactions with water.  相似文献   
8.
9.
Monometallic and bimetallic copper-containing catalysts supported on silica gel KSKG were synthesized. The bimetallic Cu—Zn catalysts were most active and selective in the hydro-genation of p-dinitrobenzene (DNB) to p-phenylenediamine (PDA) (99% at 100% conversion of DNB). The highest activity and 99% selectivity to PDA at 100% DNB conversion were demonstrated by the monometallic catalysts with a Cu content of 9%. Unlike hydrogenation on the conventional catalysts, molecular H2 is the hydrogenating agent in the presence of the copper-containing catalysts under relatively mild conditions (110–140 °C, 1.3 MPa).  相似文献   
10.
The activity of supported nickel catalysts (5–20% Ni) in the hydrogenation of p-dinitrobenzene to p-phenylenediamine was investigated. The catalysts were obtained by ureainduced precipitation. Activated carbon, alumina, titania, and silica gel were evaluated as supports. The most active catalysts, 5%Ni/TiO2 and 20%Ni/SiO2, provided 50–54% yields of p-phenylenediamine at complete dinitrobenzene conversion.  相似文献   
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