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   3篇
  物理学   3篇
  2017年   1篇
  2010年   1篇
  2009年   1篇
排序方式: 共有3条查询结果,搜索用时 62 毫秒
1
1.
对钴、镍、铜、锌元素组成的不同配合物K壳层X射线的产生截面、谱线强度比、俄歇辐射强度比进行了测定,同时研究了化学效应对K壳荧光参数和俄歇辐射强度比的影响,并根据电荷转移过程解释了这些参数的变化. 采用59.5 keV的γ射线241Am的环形放射源对样品进行激发. 用分辨率为150eV的Ultra-LEGe探测器在5.9 keV测定样品产生的K壳X射线.  相似文献
2.
A new cryptand compound carrying 2-hydroxy-1-naphthylidene Schiff base moiety (3) was designed and synthesized by reaction of the corresponding macrobicyclic amine compound (1) and 2-hydroxy-1-naphthaldehyde (2). The influence of metal cations such as Mg2+, Ca2+, Sr2+, Fe2+,Co2+, Mn2+, Zn2+, Cd2+, Hg2+, Al3+ and Pb2+ on the spectroscopic properties of the new fluoroionophore was investigated in acetonitrile-dichloromethane solution (9.5/0.5) by means of absorption and emission spectrometry. The blue shifts on the fluorescence spectrum were observed for all metal cations at 504nm. At the same time the fluorescence spectrum of the ligand showed quenching in the intensity of the signal at 504 nm for all metal cations except for Zn2+. Interaction of Co2+ with the ligand caused quenching of naphtyl fluorescence higher than 84%. The method showed good selectivity and sensitivity for Co2+ with respect to other metal cations with linear range and detection limit of 1.5 × 10−7 to 3.3 × 10−6M and 4.8 × 10−8M respectively.  相似文献
3.
Four new Schiff base ligands carrying naphthalene groups were prepared from the reaction of 2,4-diamino-6-methyl-1,3,5-triazine and 2,4-diamino-6-undecyl-1,3,5-triazine with 2-hydroxy-1-naphthaldehyde. The influence of a series of metal ions including Cu2+, Co2+, Hg2+, Al3+, Cr3+, Fe3+, Pb2+, Ni2+, Cd2+, Zn2+, Mn2+, Ag+, Ba2+, Ca2+ and Mg2+ on the spectroscopic properties of the ligands was investigated by means of absorption and emission spectrometry. The results of spectrophotometric and spectrofluorimetric titrations disclosed the complexation stoichiometry and complex stability constant of the ligands with metal ions. A simple spectrofluorimetric method was developed using the Schiff base derived from 2,4-diamino-6-undecyl-1,3,5-triazine to determine Hg2+ ion. No cleanup or enrichment of the tap water sample was required. A modified standard addition method was used to eliminate matrix effect. The standard addition graph was linear between 0.2 and 2.6 mg/L in determination of Hg2+. Detection and quantification limits were 0.08 and 0.23 mg/L, respectively. The simple and cost-effective method can be applied to water samples.  相似文献
1
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