نتایج جستجو برای: noble gases
تعداد نتایج: 50564 فیلتر نتایج به سال:
Horizontal drilling and hydraulic fracturing have enhanced unconventional hydrocarbon recovery but raised environmental concerns related to water quality. Because most basins targeted for shale-gas development in the USA have histories of both active and legacy petroleum extraction, confusion about the hydrogeological context of naturally occurring methane in shallow aquifers overlying shales r...
The beta-decay of Kr is a significant radioactive background for experiments that use liquified noble gases to search for dark matter and measure the low-energy solar neutrino flux. While there are several proposed methods for reducing Kr levels in these experiments, an independent technique is needed for measuring very low Kr levels. By selectively exciting Kr atoms to a metastable state, capt...
Figure 1: Periodic table in 1D. numbers of electrons have significant dipole moments and are thus reactive species [1]. Alternatively, atoms with even numbers of electrons are inert and do not have any dipole moment due to their symmetry. Based on these results, we have built the 1D version of the Mendeleev’s periodic table which only consists of two groups: alkali metals and noble gases, as sh...
Some non-Fourier encoding methods such as wavelet and direct encoding use spatially localized bases. The spatial localization feature of these methods enables optimized encoding for improved spatial and temporal resolution during dynamically adaptive MR imaging. These spatially localized bases, however, have inherently reduced image signal-to-noise ratio compared with Fourier or Hadamad encodin...
Unequal-sphere packing model is applied for the simulation of large number of hexagonal adlayer structures with surface coverage between theta=13 and theta=1 on the hexagonal substrate, with atomic radius of the adsorbate and substrate atoms as the only input. Each structure is characterized with respect to collective adlayer properties: the average adlayer height and the adlayer roughness. The...
Introduction: Carbonaceous chondrites contain trapped noble gases that are present in different carriers. The most abundant carrier, known as "planetary" also referred to as "Q" or "P1" [1] is formed of carbonaceous material, the nature of which remains ill-defined. It appears to be mainly composed of aromatic moieties linked by short aliphatic chains for which the best terrestrial analog may b...
Reaction of the title compound with hydrazine in the presence of air gives the 1-unsubstituted parent system via oxidative dehydrazination of the 1-hydrazino intermediate. The latter can be obtained in high yield by carrying out the hydrazinolysis step under inert gas, and it is smoothly converted into [1,2,4]-triazolo[4',3':1,6]pyridazino[4,5- b]indoles.
We present the results of our further investigation of the Gas Electron Mutiplier (GEM) photomultiplier consisting of a solid CsI photocathode coupled to a cascade of GEMs. It operates with mixtures of pure noble gases or with noble gases having small additives of nitrogen or methane. The GEM photomultiplier (GPM) reaches multiplication factors of 105}106, allowing for detection of single photo...
Dynamics of Strong-Field Laser-Induced Micro-Plasma Formation in Noble Gases D. A. Romanov, R. Compton, A. Filin, R. J. Levis 1. Center for Advanced Photonics Research, College of Science and Technology Temple University, Philadelphia, PA 19122 2. Department of Physics, Temple University, Philadelphia, PA 19122 3. Department of Chemistry, Temple University, Philadelphia, PA 19122 (Physical Revi...
[1] Noble gas data from the Glacial Drift, the shallowest aquifer in southern Michigan confirm findings by Ma et al. (2004) that modern noble gas temperatures (NGTs) are systematically below the current mean annual air temperature (MAAT) which, in turn, is similar to the ground temperature of these recharge waters. By tracking noble gas concentrations as well as stable isotope ratios through an...
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