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Lithium and sodium intercalation in TiS2 have been studied by transmission electron microscopy using lattice imaging and diffraction contrast techniques. NaxTiS2 samples (0 ≤ x ≤ 0.6) from in propylene carbonate/TiS2 batteries were found to contain a complex variety of phases inhomogeneous on a fine scale. Observations showed variable staging and a 2H phase not previously reported for this system at ambient temperatures. Observations on both NaxTiS2 and chemically prepared LixTiS2 showed highly dislocated structures. A model is proposed whereby dislocations are introduced to accommodate misfit strains caused by nonuniform intercalation and, in the case of NaxTiS2, to initiate phase transformations, leading to potentially irreversible structural changes in cycled material. 相似文献
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Lu YH Lu YW Wu CL Shao Q Chen XL Bimbong RN 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2006,65(3-4):695-701
Salicyladehyde benzoylhydrazone (SBH) has three groups suitable for forming coordination bond with transition metal. The UV-vis absorption spectra of SBH and its Co(II) complexes in various media were studied by using the deconvolution method. It is found that the structure of complex in solution is different from those in solid crystals. The nature of complexes in solution depends on acidity of the phenolic proton of SBH and on the medium. In neutral or slightly acid medium, the SBH is a non-charged bidentate ligand. And the "free" hydroxyl group on the SBH molecule makes it possible to form hydrogen bonds in solution. In basic medium, the SBH is a mono, negatively charged tridentates ligand. 相似文献
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Highly selective enzymatic reductions of aldehydes to the corresponding alcohols was performed using an E. coli JM109 whole cell biocatalyst. A selective enzymatic method for the reduction of aldehydes could provide an eco-compatible alternative to chemical methods. The simplicity, fairly wide scope and the very high observed chemoselectivity of this approach are its most unique features. 相似文献
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Gervásio A. Degrazia Otávio C. Acevedo Silvana Maldaner Umberto Rizza 《Physica A》2010,389(24):5808-5813
The classical statistical diffusion theory and the binomial autocorrelation function are used to obtain a new formulation for the turbulence dissipation rate ε. The approach employs the Maclaurin series expansion of a logarithm function contained in the dispersion parameter formulation. The numerical coefficient of this new relation for ε is 100% larger than the numerical coefficient of the classical relation derived from the exponential autocorrelation function. A similar approach shows that the dispersion parameter obtained from the even exponential autocorrelation function does not result in a relation for ε and, therefore, is not suitable for application in dispersion models. In addition, a statistical comparison to experimental ground-level concentration data demonstrates that this newly derived relation for ε as well as other formulations for the turbulence dissipation rate are suitable for application in Lagrangian stochastic dispersion models. Therefore, the analysis shows that there is an uncertainty regarding the turbulence dissipation rate function form and the autocorrelation function form. 相似文献