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   163篇
  免费   5篇
化学   125篇
力学   6篇
数学   24篇
物理学   13篇
  2023年   2篇
  2022年   1篇
  2021年   4篇
  2020年   1篇
  2019年   2篇
  2018年   3篇
  2017年   2篇
  2016年   6篇
  2015年   3篇
  2014年   6篇
  2013年   4篇
  2012年   6篇
  2011年   9篇
  2010年   10篇
  2009年   2篇
  2008年   5篇
  2007年   6篇
  2006年   6篇
  2005年   3篇
  2004年   7篇
  2003年   2篇
  2002年   3篇
  2001年   1篇
  2000年   2篇
  1999年   3篇
  1998年   5篇
  1997年   2篇
  1996年   4篇
  1995年   3篇
  1994年   1篇
  1993年   1篇
  1992年   2篇
  1991年   1篇
  1990年   8篇
  1989年   5篇
  1988年   7篇
  1987年   5篇
  1986年   9篇
  1985年   9篇
  1984年   3篇
  1978年   1篇
  1977年   1篇
  1976年   1篇
  1966年   1篇
排序方式: 共有168条查询结果,搜索用时 156 毫秒
1.
A rapid and selective method has been developed for the determination of cadmium in environmental samples by thermal neutron activation analysis, employing substoichiometric solvent extraction technique. Alcoholic solution of 2-mercaptobenzothiazole /2-HMBT/ has been used for the substoichiometric extraction of Cd/II/ from an aqueous solution of pH 7.0 into methyl iso-butyl ketone /MIBK/.  相似文献   
2.
The toxicity of Se, Cd, and Hg as environmental pollutants and the impact of these elements on the aquatic ecosystem is undisputed. The present paper reports an investigation of the concentration of Cd, Se, and Hg in an aquatic environment of a large metropolitan city like Bombay. As the toxicity of these elements manifests itself at micro and submicro levels, the very sensitive technique of neutron activation analysis was employed. A sequential substoichiometric extraction technique for the separation of radiochemically pure203Hg,75Se, and115–115mCd from the neutron irradiated target has also been employed.  相似文献   
3.
The high thermal neutron flux provided by the CIRUS reactor (1×1013 n cm–2s–1) has been used to determine elements having long half-lives or poor thermal neutron crosssections. Selective cooling time and the use of a high resolution HPGe detector in conjunction with a PC based MCA unit have made it possible to analyze many elements in a single irradiation run. The method developed has been used for the analysis of ores such as Ilmenite, Rutile, Sillimanite, Garnet, Zircon and Monazite.  相似文献   
4.
An accurate and simple method has been developed for the determination of Pt, Ru, Ir and other elements employing instrumental neutron activation analysis (INAA). Nondestructive analysis has been carried out for the determination of these elements in different rock samples such as Dolerite, Dyke Dolerite, Country Basalt, Hyaloclastite, Trachyte, Ijolite, Spillite, Diorite and Lamprophyre from various locations like Daman, Tapti, Murud, Talasari, Ranala and Bassein in Maharashtra state. High flux provided by the CIRUS reactor (1×1013 n cm–2s–1) has been used for thermal neutron bombardment followed by radioassaying of the (n,) products on a HPGe detector coupled to a PC-based MCA unit.  相似文献   
5.
A rapid, selective and simple method have been developed for the determination of palladium in alloys and ores by thermal neutron activation analysis, incorporating substoichiometric solvent extraction of Pd/II/ with 1,2,3-benzotriazole /1,2,3-BT/ into methyl iso-butyl ketone /MIBK/. Two samples and a standard can be processed and counted within two hours.  相似文献   
6.
Chromium has been determined in environmental samples. The method described here involves the irradiation of environmental samples and a g quantity of standard with thermal neutrons at the self-serve position in the CIRUS reactor, followed by dissolution of the sample and standard in the presence of a milligram amount of carrier. Both the sample and the standard are subjected to substoichiometric extraction under controlled experimental conditions with alizarin into cyclohexane. An aliquot of the organic phase was counted on a gamma-ray spectrometer. The concentration of Cr in water samples from Bombay and Karad City, and the accuracy, precision and sensitivity of the method are discussed.  相似文献   
7.
Ideal conditions for the extraction of Au/III/ with 2-mercaptobenzothiazole/2-HMBT/ into chloroform have been established. The effects of various parameters such as pH, time of equilibration, solvents, cation interferences, anion interferences and stoichiometry of the metal to reagent have been established.  相似文献   
8.
9.
The reagent 2-mercaptobenzothiazole /2-HMBT/ has been used for the solvent extraction of Ru/III/. The extraction coefficient value of Ru/III/ has been evaluated, based on various parameters such as, effect of molarity of the acid, time of equilibration, time of heating, effect of various solvents and effect of various salts. The stoichiometry of the metal to reagent was determined by the method of substoichiometric extraction of slope-ratio method and was found to be 13. Separation factor and decontamination factor for various elements have also been studied.  相似文献   
10.
A rapid and selective method has been developed for the extraction of Co/II/ with isonitrosobenzoylacetone into chloroform. The effect of various parameters on the extraction coefficient value such as effect of pH, time of equilibration, effect of various cations and anions have been evaluated. The stoichiometry of metal to reagent determined by the method of substoichiometric extraction was found to be 12. It was further supported by the slope ratio method.  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