نتایج جستجو برای: h h2o
تعداد نتایج: 544560 فیلتر نتایج به سال:
OBJECTIVE If lungs could be retrieved for transplant after circulatory arrest, the shortage of donors might be significantly alleviated. Great controversy still exists concerning the optimal mode of preservation of pulmonary grafts in these non-heart-beating donors. METHODS Graft function was measured in an isolated room air-ventilated rabbit lung model during reperfusion with homologous, dil...
We report the detection of absorption by interstellar hydroxyl cations and water cations, along the sight-line to the bright continuum source W49N. We have used Herschel’s HIFI instrument, in dual beam switch mode, to observe the 972 GHz N = 1–0 transition of OH and the 1115 GHz 111−000 transition of ortho-H2O. The resultant spectra show absorption by ortho-H2O, and strong absorption by OH, in ...
Isotopic tracer and kinetic measurements were used to determine the identity and reversibility of elementary steps required for CH4–CO2 , CH4–H2O and CH4 decomposition reactions on supported Ir clusters. The results led to a simple and rigorous mechanism that includes steps required for these reactions as well as water–gas shift reactions. All three CH4 reactions gave similar forward rates, rat...
Accurate experimental values for the free energies of hydration, or the free energies of solvation, of the H+, OH-, and H3O ions are of fundamental importance. By use of the most accurate value for the free energy of solvation of H+, the known value for the free energy of solvation of water, and the known values for the gas phase and aqueous phase deprotonation of water, the corresponding exper...
The adsorption of water multilayers on a well defined single crystal, hydroxyl-terminated ZnO-surface, H(1x1)-O-ZnO(0001) surface has been investigated using infrared (IR) spectroscopy, helium atom scattering (HAS) and X-ray photoelectron spectroscopy (XPS). The results reveal the formation of well ordered mono-, bi- and multilayers of D2O and H2O on this substrate. On the bare hydroxyl-covered...
The basic structural unit of the title polymeric ribbon, {[Li2(C5H3N2O2)2(H2O)2]·H2O} n , is a centrosymmetric dinuclear complex in which the two Li(I) ions are bridged by two carboxyl-ato O atoms, to generate a centrosymmetric Li2O2 core. These are connected into a chain along [01-1] by carboxylic acid-carbonyl-O bonds. The tetra-hedral coordination of the Li(I) cation is completed by an aqua ...
We report a sensitive search for deuterated water (HDO) in comet 8P/Tuttle using high-resolution spectroscopy at infrared (IR) wavelengths. The deuterium enrichment of cometary water is one of the most important cosmogonic indicators in comets. The (D/H)H2O ratio preserves information about the conditions under which comet material formed, and tests the possible contribution of comets in delive...
The title compound, Mn2Zn(PO4)2·H2O, was obtained under hydro-thermal conditions. The structure is isotypic with other transition metal phosphates of the type M 3- xM' x (PO4)2·H2O, but shows no statistical disorder of the three metallic sites. The principal building units are distorted [MnO6] and [MnO5(H2O)] octa-hedra, a distorted [ZnO5] square pyramid and two regular PO4 tetra-hedra. The con...
In the title compound, [Tb(C2H3O2)2(C11H10N4)(H2O)2]NO3·H2O, the Tb3+ ion is nine-coordinated in a distorted tricapped trigonal-prismatic geometry by the three N atoms of the tridentate 1-(pyridin-2-yl-methyl-idene)-2-(pyridin-2-yl)hydrazine ligand, four carboxyl-ate O atoms of two chelating acetate groups and two O atoms of the coordinating water mol-ecules. The organic hydrazine ligand is dis...
There are 30026 symmetry-distinct ways to arrange 20 water molecules in a dodecahedral cage with nearly optimum hydrogen bond lengths and angles, analogous to the arrangements that give rise to the zero-point entropy in ice-Ih. The energy of hydrogen bond isomers in (H2O)20 , assumed to be similar in the past, differs by up to 70 kcal/mol. The isomers differ widely in their hydrogen bond length...
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