نتایج جستجو برای: optical density ratios
تعداد نتایج: 772017 فیلتر نتایج به سال:
Current methods for estimating 5'-nucleotidase activity in human serum are critically discussed. The requirements for specificity in the assay procedure are re-emphasised, special consideration being given to the absolute concentrations as well as the molar ratios of true and alternative substrates. Substrate-inhibition, described in a previous Report is believed to be due to a non-linear relat...
In this manuscript, density functional theory was used to explore structural, vibrational and optical properties of the (Sc2O3)n (n=1-5) cluster systems using DFT/B3LYP/LanL2DZ level of computation. Different stable isomers were obtained and numerous chemical parameters such as HOMO-LUMO gap, ionization potential and electron affinity were calculated successfully. Stability of the clusters was ...
Emission line ratios have been essential for determining physical parameters such as gas temperature and density in astrophysical gaseous nebulae. With the advent of panoramic spectroscopic devices, images of regions with emission lines related to these physical parameters can, in principle, also be produced. We show that, with observations from modern instruments, it is possible to transform i...
the aim of this research was to construct an equipped hive with the acquisition, communication and analysis systems to send images on-line, wirelessly. this system could be used to evaluate density of bee colonies and also work as bait box to eliminate bee pest, if necessary. in this study, two methods, optical flow and neighborhood gray-tone difference matrix, were used to determine hive condi...
By introducing a thin ZnO layer as an optical spacer, we have demonstrated that inserting this layer between an active layer and a reflective electrode results in a re-distribution of the optical electric field inside bulk heterojunction solar cells. A theoretical analysis by optical modeling showed that the thin ZnO layer could shift the position of the maximum of the electric field into the a...
Self-assembled InN nanodots have been prepared at 650 degrees C with various V/III ratios from 500 to 30 000 by metal-organic chemical vapor deposition (MOCVD). It is found that the dot density and morphological size as well as the optical properties all display drastic changes at V/III = 12 000. Generally, denser and smaller InN nanodots with higher emission energy and narrower linewidth were ...
We present deep optical spectra of the archetypal young planetary nebula (PN) NGC7027, covering a wavelength range from 3310 to 9160 Å. The observations were carried out by uniformly scanning a long slit across the entire nebular surface, thus yielding average optical spectra for the whole nebula. A total of 937 emission features are detected. The extensive line list presented here should prove...
Seyfert narrow line region (NLR) emission line ratios are remarkably uniform, displaying only ∼0.5 dex variation between galaxies, and even less within an individual object. Previous photoionization and shock models of this region were unable to explain this observation without the introduction of arbitrary assumptions or additional parameters. Dusty, radiation pressure dominated photoionizatio...
Maximizing cell growth rate and cell yield are among the most important features of a successful mammalian cell culture production process. To minimize time and resources needed to scale up cell mass it is important to maintain the cultures in exponential growth at every scale. Here we report results comparing viable cell counts, packed cell volume, intracellular nucleotide ratios, cell cycle a...
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