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   1篇
  完全免费   2篇
  物理学   3篇
  2017年   1篇
  2012年   1篇
  2009年   1篇
排序方式: 共有3条查询结果,搜索用时 31 毫秒
1
1.
利用同步辐射光电离质谱结合理论计算, 研究了异亮氨酸的真空紫外光诱导电离解离.在光子能量为13 eV的质谱中探测到了m/z=86、75、74、69、57、46、45、44、41、30、28、18的碎片离子.对于异亮氨酸的主要碎片离子为:C5H12N+ (m/z=86)、C2H5NO4+ (m/z=75)、C5H9+ (m/z=69)、C4H9+(m/z=57)和CH4N+(m/z=30).由光电离效率曲线得到出现势分别为:8.84±0.07、9.25±0.06、10.20±0.12、9.25±0.10、11.05±0.07 eV.结合量化理论计算(B3LYP/6-31++G(d,p)),详细给出了它们可能的生成路径.这些解离通道包括简单的键断裂反应和涉及中间体、过渡态的反应,实验值和理论计算的离子出现能或势垒一致.  相似文献
2.
Interference fringes are obtained in a field-emission microscopy (FEM) study of a multi-walled carbon nanotube (MWCNT) with two open-ended branches.The FEM pattern,which is composed of three parallel streaks,can be interpreted by using classical Young’s double-slit interference with the ends of the two MWCNT branches treated as two secondary sources of the electron wave.The origin of the coherency of the electron beams from the two branches is discussed on the basis of the quantitative analysis of the FEM pattern.The result suggests a new approach to obtaining a coherent electron source.  相似文献
3.
The photoionization and dissociation photoionization of toluene have been studied using quantum chemistry methods.The geometries and frequencies of the reactants,transition states and products have been performed at B3LYP/6-311++G (d,p) level,and single-point energy calculations for all the stationary points were carried out at DFT calculations of the optimized structures with the G3B3 level.The ionization energies of toluene and the appearance energies for major fragment ions,C7H7+,C6H5+,C5H6+,C5H5+,are determined to be 8.90,11.15 or 11.03,12.72,13.69,16.28 eV,respectively,which are all in good agreement with published experimental data.With the help of available published experimental data and theoretical results,four dissociative photoionization channels have been proposed:C7H7++H,C6H5++CH3,C5H6++C2H2,C5H5++C2H2+H.Transition structures and intermediates for those isomerization processes are determined in this work.Especially,the structures of C5H6+ and C5H5+ produced by dissociative photoionization of toluene have been defined as chain structure in this work with theoretical calculations.  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