نتایج جستجو برای: xrf
تعداد نتایج: 3086 فیلتر نتایج به سال:
We present optical and near-infrared follow-up observations of the X-ray flash (XRF) of 2003 July 23. Our observations in the R band cover the temporal range from 4.2 hr to 64 days after the high-energy event. We also present the results of multicolor imaging extending to the K band on three epochs. The light curve of the R-band afterglow the first week after the burst is similar to the light c...
The origin of X-ray Flashes (XRFs) is still a mystery and several models have been proposed. To disentangle among these models, an important observational tool is the measure of the XRF distance scale, so far available only for a few of them.
How to calculate lead concentration and concentration uncertainty in XRF in vivo bone lead analysis.
The authors provide a substantial correction for calculating estimates of lead concentration and uncertainty for in vivo X-ray fluorescent bone analysis with Cd-109 source. Based on general principles, they provide mathematical techniques for propagation of uncertainties in XRF analysis. They give additional considerations for lowering the detection limit and improving spectral data quality.
The paper deals with the application of X-ray fluorescence and diffraction for the routing control of a chemical content of an electrolysis cell in aluminum reduction plants. Among two approaches XRD meets technological requirements on accuracy, time limit and the cost of analysis. XRF demonstrates insufficient accuracy because of sample preparation problem.
Our work shows that XRD and XRF studies on missions to Mars and Saturn's moons could be carried out using the radioisotopes Rh-101 or Am-241 as sources of radiation. We discuss geological questions which we believe should be answered before any search for biological structures or pre-forms of life. We also suggest a method to produce Rh-101.
The paper deals with the application of X-ray fluorescence and diffraction for the routing control of a chemical content of an electrolysis cell in aluminum reduction plants. Among two approaches XRD meets technological requirements on accuracy, time limit and the cost of analysis. XRF demonstrates insufficient accuracy because of sample preparation problem.
We give an explicit formula of the inverse polynomial of a permutation polynomial of the form xrf(xs) over a finite field Fq where s | q − 1. This generalizes results in [6] where s = 1 or f = g q−1 s were considered respectively. We also apply our result to several interesting classes of permutation polynomials.
Enhancing nutrient uptake and the subsequent elemental transport from the sites of application to sites of utilization is of great importance to the science and practical field application of foliar fertilizers. The aim of this study was to investigate the mobility of various foliar applied zinc (Zn) formulations in sunflower (Helianthus annuus L.) and to evaluate the effects of the addition of...
The concentration of halogens (Cl, Br) and sulfate in seawater during the Archaean eon have important implications for the evolution of Earth’s hydrosphere and atmosphere and the development of early life. Insights into the composition of Archaean seawater and hydrothermal fluids can be obtained by direct analysis of fluid inclusions preserved in Archaean sediments and hydrothermal systems. Her...
Metallic elements are required in numerous essential biological processes of the human body. Transition metal elements like iron, zinc or copper bound to proteins (metalloproteins) perform a variety of complex biological functions as catalysts which regulate biochemical reactions and physiological functions in cells and organs. Published reports have been pointing out that excessive accumulatio...
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