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971.
Theoretical studies on atmospheric chemistry of HFE‐347mcc3: reactions with OH radicals and Cl atoms
Bhupesh Kumar Mishra Makroni Lily Asit K. Chandra Ramesh Chandra Deka 《Journal of Physical Organic Chemistry》2014,27(10):811-817
Detailed theoretical investigation has been performed on the mechanism, kinetics and thermochemistry of the gas phase reactions of CF3CF2CF2OCH3 (HFE‐347mcc3) with OH radicals and Cl atoms using M06‐2X/6‐31 + G(d,p) level of theory. Reaction profiles are modeled including the formation of pre‐reactive and post‐reactive complexes at entrance and exit channels, respectively. Using group‐balanced isodesmic reactions, the standard enthalpies of formation for species are also reported. The calculated bond dissociation energy for C―H bond is in good agreement with previous data. The rate constants of the two reactions are determined for the first time in a wide temperature range of 250–1000 K. At 298 K, the calculated rate coefficients are in good agreement with the experimental results. The atmospheric life time of HFE‐347mcc3 is estimated to be 4.4 years. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
972.
973.
We present a streamline diffusion shock capturing spacetime discontinuous Galerkin (DG) method to approximate nonlinear systems of conservation laws in several space dimensions. The degrees of freedom are in terms of the entropy variables and the numerical flux functions are the entropy stable finite volume fluxes. We show entropy stability of the (formally) arbitrarily high order accurate method for a general system of conservation laws. Furthermore, we prove that the approximate solutions converge to the entropy measure valued solutions for nonlinear systems of conservation laws. Convergence to entropy solutions for scalar conservation laws and for linear symmetrizable systems is also shown. Numerical experiments are presented to illustrate the robustness of the proposed schemes. 相似文献
974.
Raman spectroscopic measurements were carried out in the temperature range 10–300 K to understand the low‐temperature antiferroelectric (AFE)–ferroelectric (FE) phase transition in NaNbO3. Several modes in the low wavenumber range were found to disappear, while some new modes appeared across the transition. The temperature dependence of mode wavenumbers suggests that, during cooling, the AFE–FE phase transition begins to occur at 180 K, while the reverse transition starts at 260 K during heating. During cooling, the two phases were found to coexist in the temperature range of 220–160 K. Upon heating, the FE phase is retained up to 240 K and both FE and AFE phases coexist in the temperature range 240–300 K. In contrast to the earlier reports, the present results suggest a different coexistence region and the reverse transition temperature. The reported relaxor‐type FE behaviour over a broad temperature is consistent with the observed coexistence of phases during cooling and heating cycles. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
975.
A. K. Mishra S. B. Mishra N. K. Kaushik 《Russian Journal of Coordination Chemistry》2009,35(4):296-301
Nickel(II) complexes of type [Ni(L)2Cl2] and [Ni(L)2(OCOCH3)2], where L = (cyclohexyl-N-thio)-1,2-ethylenediamine (L1) and (cyclohexyl-N-thio)-1,3-propanediamine (L2) has been synthesized and characterized by elemental analysis, FT-IR, mass, UV-Vis, and 1H NMR spectroscopic studies. The thiodiamines coordinate as a bidentate N-S ligand. The ratio of the metal: ligand was 1:
2 for all the complexes. The binding sites are the azomethine nitrogen and thioamide sulfur. The complexes are found to be
soluble in acetone, dimethylformamide, and dimethylsulfoxide. All the complexes were found amorphous in nature. Molar conductance
values in DMSO indicate the nonelectrolyte nature of the complexes. In vitro antifungal and in vitro antibacterial studies
were performed against fungal and bacterial strains, Aspergillus fumigatus, Aspergillus flavus, and Aspergillus niger, and Staphylococcus epidermidis, Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa, respectively. Preliminary antimicrobial screening shows the good results against both the fungal and the bacterial strains,
which can lead through the investigation of better drug.
The article is published in the original. 相似文献
976.
Ujjwal Koley Siddhartha Mishra Nils Henrik Risebro Magnus Svärd 《BIT Numerical Mathematics》2009,49(2):375-395
We describe high order accurate and stable finite difference schemes for the initial-boundary value problem associated with
the magnetic induction equations. These equations model the evolution of a magnetic field due to a given velocity field. The
finite difference schemes are based on Summation by Parts (SBP) operators for spatial derivatives and a Simultaneous Approximation
Term (SAT) technique for imposing boundary conditions. We present various numerical experiments that demonstrate both the
stability as well as high order of accuracy of the schemes.
相似文献
977.
The nanometric mixed tin-titanium oxide doped with a M(5+) cation was recently shown as a promising thermoelectric material. We report here synthesis of novel molecular precursors for above material using a convenient approach of reacting a metal chloride with a metal alkoxide. Heterometallic complexes with simple addition formula [(EtOH)(2)(OEt)(2)Ti(μ-OEt)(2)SnCl(4)] (1·EtOH) and [(EtOH)(OEt)(3)Ta(μ-OEt)(2)SnCl(4)] (2) were isolated in quantitative yield, which on recrystallization from isopropanol afforded mixed-alkoxide complexes [(Pr(i)OH)(2)(OPr(i))(2)Ti(μ-OEt)(2)SnCl(4)] (3) and [(Pr(i)OH)(OPr(i))(3)Ta(μ-OEt)(2)SnCl(4)] (4), respectively, thus indicating the robustness of the heterometallic M(μ-OEt)(2)Sn core in the solution phase. Facile conversion of these precursors to halide-free spinodal form of Ta(5+)-doped TiO(2)-SnO(2) as a potential thermoelectric material is reported. 相似文献
978.
A new coumarin based hydrazone (receptor 1) synthesized by modifying one of our earlier reported receptor detected fluoride ion selectively through naked eye in aq. DMSO (5:95, v/v). It was also able to detect fluoride through naked eye in a toothpaste sample. The addition of 1 equiv. of fluoride as its tetrabutylammonium salt to the 5 × 10−5 M aq. DMSO solution of the receptor 1 produced red color while the similar addition of acetate produced faint pink color. The dihydrogenphosphate and a variety of other anions were not able to produce any significant color change with receptor 1 under similar experimental conditions. The corresponding UV-vis measurements showed a bathochromic shifting of 455 nm band of receptor 1 to 514 and 484 nm for fluoride and acetate, respectively. The non-linear fittings of corresponding UV-vis titration data in 1:1 binding equation yielded association constants in 105:1 ratio for fluoride and acetate, respectively. The 1H NMR titrations studies shade further light on their mode of binding with receptor 1. The quantum mechanical calculations through time dependant density functional theory (TD-DFT) using basis set b3lyp/6-311g** supported our experimental findings nicely. 相似文献
979.
Mahato P Ghosh A Mishra SK Shrivastav A Mishra S Das A 《Chemical communications (Cambridge, England)》2010,46(48):9134-9136
Selective colorimetric detection of ATP in physiological conditions by a Zn(II)-based receptor is reported. This reagent was found to be non-toxic to the living cells and could be used for studying the growth of the yeast cells. 相似文献
980.
In this article, a convergence theorem and several comparison theorems are presented for a subclass of proper splittings of matrices introduced recently. 相似文献