scholarly journals New light elements for selected eclipsing stars.

1951 ◽  
Vol 56 ◽  
pp. 53 ◽  
Author(s):  
Frank Bradshaw Wood
Keyword(s):  
Light Elements ◽  
Eclipsing Stars

Scattering-angle dependence of signal/background ratio of inner-shell electron excitation loss in EELS

1983 ◽  
Vol 41 ◽  
pp. 390-391
Author(s):  
T. Oikawa ◽  
M. Inoue ◽  
T. Honda ◽  
Y. Kokubo
Keyword(s):  
Energy Loss ◽  
Electron Excitation ◽  
Heavy Elements ◽  
Background Intensity ◽  
Light Elements ◽  
Energy Analyzer ◽  
High Background ◽  
Scattering Angle ◽  
Angle Dependence ◽  
Shell Electron

EELS allows us to make analysis of light elements such as hydrogen to heavy elements of microareas on the specimen. In energy loss spectra, however, elemental signals ride on a high background; therefore, the signal/background (S/B) ratio is very low in EELS. A technique which collects the center beam axial-symmetrically in the scattering angle is generally used to obtain high total intensity. However, the technique collects high background intensity together with elemental signals; therefore, the technique does not improve the S/B ratio. This report presents the experimental results of the S/B ratio measured as a function of the scattering angle and shows the possibility of the S/B ratio being improved in the high scattering angle range.Energy loss spectra have been measured using a JEM-200CX TEM with an energy analyzer ASEA3 at 200 kV.Fig.l shows a typical K-shell electron excitation edge riding on background in an energy loss spectrum.

Quantitative EPMA of nitrogen : A tricky element in the electron-probe microanalyzer

1992 ◽  
Vol 50 (2) ◽  
pp. 1622-1623
Author(s):  
G.F. Bastin ◽  
H.J.M. Heijligers
Keyword(s):  
Background Subtraction ◽  
Electron Probe ◽  
Detection System ◽  
Higher Order ◽  
Light Elements ◽  
Strong Suppression ◽  
Electron Probe Microanalyzer ◽  
Quantitative Epma ◽  
Peak Count ◽  
Lead Stearate

Among the ultra-light elements B, C, N, and O nitrogen is the most difficult element to deal with in the electron probe microanalyzer. This is mainly caused by the severe absorption that N-Kα radiation suffers in carbon which is abundantly present in the detection system (lead-stearate crystal, carbonaceous counter window). As a result the peak-to-background ratios for N-Kα measured with a conventional lead-stearate crystal can attain values well below unity in many binary nitrides . An additional complication can be caused by the presence of interfering higher-order reflections from the metal partner in the nitride specimen; notorious examples are elements such as Zr and Nb. In nitrides containing these elements is is virtually impossible to carry out an accurate background subtraction which becomes increasingly important with lower and lower peak-to-background ratios. The use of a synthetic multilayer crystal such as W/Si (2d-spacing 59.8 Å) can bring significant improvements in terms of both higher peak count rates as well as a strong suppression of higher-order reflections.

Utilization of the nuclear energy of the light elements

1991 ◽  
Vol 161 (5) ◽  
pp. 171-175 ◽  
Author(s):  
Yu.B. Khariton ◽  
Ya.B. Zeldovich ◽  
I.I. Gurevich ◽  
I.Ya. Pomeranchuk
Keyword(s):  
Nuclear Energy ◽  
Light Elements

Hydrides and Borohydrides of Light Elements

1947 ◽  
Author(s):  
H. Schlesinger ◽  
G. W. Schaeffer
Keyword(s):  
Light Elements

Galactic Cosmic Rays and the Evolution of Light Elements

1998 ◽  
Vol 499 (2) ◽  
pp. 735-745 ◽  
Author(s):  
Martin Lemoine ◽  
Elisabeth Vangioni‐Flam ◽  
Michel Casse
Keyword(s):  
Cosmic Rays ◽  
Galactic Cosmic Rays ◽  
Light Elements

P‐9: Understanding Diffusion Behaviors of Light Elements in OLEDs

2021 ◽  
Vol 52 (1) ◽  
pp. 1088-1090
Author(s):  
Jae Bum HAN ◽  
Young-Gil Park ◽  
Soo Im Jeong ◽  
Nari Ahn
Keyword(s):  
Light Elements ◽  
Diffusion Behaviors

scholarly journals Possible Pitfalls in the Analysis of Minerals and Loose Materials by Portable XRF, and How to Overcome Them

Minerals ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 33
Author(s):  
Valérie Laperche ◽  
Bruno Lemière
Keyword(s):  
Fluorescence Spectroscopy ◽  
Laboratory Data ◽  
Data Sets ◽  
Light Elements ◽  
Portable Xrf ◽  
X Ray ◽  
Protective Films ◽  
The Matrix ◽  
Valuable Complement ◽  
Physical Effects

Portable X-ray fluorescence spectroscopy is now widely used in almost any field of geoscience. Handheld XRF analysers are easy to use, and results are available in almost real time anywhere. However, the results do not always match laboratory analyses, and this may deter users. Rather than analytical issues, the bias often results from sample preparation differences. Instrument setup and analysis conditions need to be fully understood to avoid reporting erroneous results. The technique’s limitations must be kept in mind. We describe a number of issues and potential pitfalls observed from our experience and described in the literature. This includes the analytical mode and parameters; protective films; sample geometry and density, especially for light elements; analytical interferences between elements; physical effects of the matrix and sample condition, and more. Nevertheless, portable X-ray fluorescence spectroscopy (pXRF) results gathered with sufficient care by experienced users are both precise and reliable, if not fully accurate, and they can constitute robust data sets. Rather than being a substitute for laboratory analyses, pXRF measurements are a valuable complement to those. pXRF improves the quality and relevance of laboratory data sets.

scholarly journals Lithium abundances in late main sequence stars. The case of the hyades

1984 ◽  
Vol 105 ◽  
pp. 529-531
Author(s):  
A. Baglin ◽  
P.J. Morel
Keyword(s):  
Low Temperature ◽  
Transport Process ◽  
Main Sequence ◽  
Light Elements ◽  
Main Sequence Stars

It is well known that light elements like lithium are good indicators of the hydrodynamical behaviour of the outerlayers of the stars. As they are nuclearly destroyed at low temperature, i.e. close to the surface, their surface abundances reflect the nature of the transport process at work between the photosphere and the nuclear destruction region.

Sign in / Sign up

Export Citation Format

Share Document