A combined zero electronic kinetic energy spectroscopy and ion-pair dissociation imaging study of the F2+(XΠg2) structure

2005 ◽  
Vol 122 (13) ◽  
pp. 134308 ◽  
Author(s):  
Jie Yang ◽  
Yusong Hao ◽  
Juan Li ◽  
Chang Zhou ◽  
Yuxiang Mo
Keyword(s):  
Kinetic Energy ◽  
Imaging Study ◽  
Ion Pair

scholarly journals Quantitative oscillator strengths for ionic fragmentation of C 1s and O 1s excited CO

2004 ◽  
Vol 82 (6) ◽  
pp. 1052-1060 ◽  
Author(s):  
A CO Guerra ◽  
J B Maciel ◽  
C C Turci ◽  
R C Bilodeau ◽  
A P Hitchcock
Keyword(s):  
Mass Spectrometry ◽  
Kinetic Energy ◽  
Cross Sections ◽  
Time Of Flight ◽  
Branching Ratios ◽  
Ion Pair ◽  
Oscillator Strengths ◽  
Ion Trajectory ◽  
Ion Fragmentation ◽  
Flight Mass Spectrometry

Ionic photofragmentation of carbon monoxide following carbon 1s and oxygen 1s excitation has been measured quantitatively with tuned synchrotron light and time-of-flight mass spectrometry using a Wiley–McLaren apparatus modified with an additional ion lens for improved quantitative performance. The sensitivity of the apparatus to kinetic energy and angular distribution effects has been characterized for selected lens settings through ion trajectory simulations and experimental measurements. Three distinct modes of the added lens have been identified (focus, defocus, and maximum). The focus mode has the least sensitivity to details of the angular and ion kinetic energy distribution and, therefore, is the best mode for measuring quantitative partial ion and ion-pair yields. The defocus mode has the most sensitivity to angular and kinetic energy distributions and, therefore, is the mode that provides the most information about the kinematics of photofragmentation. Branching ratios for ion and ion-pair production in all positive ion fragmentation channels were recorded from 280 to 330 eV (C 1s) and from 520 to 570 eV (O 1s) in the "focus" mode. Quantitative oscillator strengths were derived by combining these branching ratios with absolute total ion yield spectra. The results are compared to literature values.Key words: CO, time-of-flight mass spectrometry, inner-shell excitation, quantitative oscillator strengths, cross sections.

Ionization and dissociative ionization of CO2 by electron impact

1977 ◽  
Vol 55 (21) ◽  
pp. 1889-1897 ◽  
Author(s):  
N. Bussières ◽  
P. Marmet
Keyword(s):  
Kinetic Energy ◽  
Electron Impact ◽  
Signal To Noise Ratio ◽  
Ion Pair ◽  
Pair Formation ◽  
Negative Ion ◽  
High Signal ◽  
Signal To Noise ◽  
Fragment Ions ◽  
Zero Kinetic Energy

Using a very sensitive apparatus with a high signal-to-noise ratio, new structures are observed in the ionization curve of CO2 by electron impact in the first 10 V above the ionization threshold. Neutral and negative ion levels are observed and related to npσu and npπu series converging to Ā, [Formula: see text], and [Formula: see text] levels of CO2+. Data for the fragment ions CO+, O+, and C+ are also presented; it is shown that they can be formed with zero kinetic energy. No ion pair formation can be detected at threshold.

High resolution STEM imaging study on high Tc superconductor YBa2CuaO7-x

1988 ◽  
Vol 46 ◽  
pp. 882-883
Author(s):  
H.-J. Ou ◽  
J. M. Cowley
Keyword(s):  
Crystal Structure ◽  
High Resolution ◽  
Grain Boundary ◽  
Strong Field ◽  
Imaging Study ◽  
Structure Defects ◽  
High Tc ◽  
High Tc Superconductor ◽  
Diffraction Patterns ◽  
Lattice Planes

Using the dedicate VG-HB5 STEM microscope, the crystal structure of high Tc superconductor of YBa2Cu3O7-x has been studied via high resolution STEM (HRSTEM) imaging and nanobeam (∽3A) diffraction patterns. Figure 1(a) and 2(a) illustrate the HRSTEM image taken at 10' times magnification along [001] direction and [100] direction, respectively. In figure 1(a), a grain boundary with strong field contrast is seen between two crystal regions A and B. The grain boundary appears to be parallel to a (110) plane, although it is not possible to determine [100] and [001] axes as it is in other regions which contain twin planes [3]. Following the horizontal lattice lines, from left to right across the grain boundary, a lattice bending of ∽4° is noticed. Three extra lattice planes, indicated by arrows, were found to terminate at the grain boundary and form dislocations. It is believed that due to different chemical composition, such structure defects occur during crystal growth. No bending is observed along the vertical lattice lines.

Alterations in regional decreased cerebral blood flow in patients with irritable bowel syndrome-A PET imaging study

2001 ◽  
Vol 120 (5) ◽  
pp. A637-A637
Author(s):  
Y RINGEL ◽  
D DROSSMAN ◽  
T TURKINGTON ◽  
B BRADSHAW ◽  
R COLEMAN ◽  
...  
Keyword(s):  
Blood Flow ◽  
Irritable Bowel Syndrome ◽  
Cerebral Blood Flow ◽  
Pet Imaging ◽  
Imaging Study ◽  
Irritable Bowel
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