Materials Literature
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Optical absorption and photoelectron spectra of CsPbCl 3 and CsPbBr 3 have been studied. A sharp absorption peak is found at about 3 eV in CsPbCl 3 and 2.4 eV in CsPbBr 3 and its position shifts toward lower energy as the temperature decreases. XPS and UPS measurements of the materials suggest that this first peak is…
A classical model of the polarizability of π-bonded molecules is developed. The model is an extension of the atom dipole model which allows charge transfer within the molecule to reproduce the effect of delocalized π electrons. The model is applied to several test systems and is found to provide better agreement with…
Phonons in a metal have a finite lifetime due to the emission of electron-hole pairs. This process leads to an electron-phonon contribution ${W}_{\mathrm{ep}}^{p}$ to the thermal resistance, which limits the lattice thermal conductivity ${\ensuremath{\kappa}}_{p}$. We present a summary of the available experimental da…
Results of Raman scattering experiments associated with in-plane intercalate modes in graphite-bromine are reported. The spectra are interpreted in terms of models in which the molecular character of the bromine is retained and the molecular ordering of the intercalate layer is closely related to that in the layer str…
The shift of the optical-absorption edge when evaporated films are annealed at the glass-transition temperature is investigated in amorphous Ge${\mathrm{Se}}_{2}$, ${\mathrm{As}}_{2}$${\mathrm{S}}_{3}$, and ${\mathrm{As}}_{2}$${\mathrm{Se}}_{3}$, and is related to structural studies described in the previous paper. A…
The structure of evaporated ${\mathrm{As}}_{2}$${\mathrm{S}}_{3}$, ${\mathrm{As}}_{2}$${\mathrm{Se}}_{3}$, and Ge${\mathrm{Se}}_{2}$ films, and the influence of annealing at the glasstransition temperature, are studied by extended x-ray-absorption fine structure (EXAFS) and by Raman spectroscopy. In addition, the topo…
The dielectric functions and optical conductivities of Cr${\mathrm{O}}_{2}$, Mo${\mathrm{O}}_{2}$, and W${\mathrm{O}}_{2}$ have been obtained from reflectivity measurements, and the results are interpreted on the basis of qualitative models proposed for the band structures of the transition-metal dioxide series. Cr${\…
Mössbauer spectra of the polycrystalline form of the square planar compound α,β,γ,δ-tetraphenylporphinato–iron (II) have been observed at a variety of temperatures. Analysis of the resulting spectra yield a positive electric field gradient interaction with quadrupole splitting ΔE=1.51 mm/s (4.2 K) and 1.52 mm/s (300 K…
An electronegativity scale is derived for the noble and transition metals, based on their electron-band theory description. The tendency of $d$-band electron and hole states to hybridize is used to estimate the propensity for a particular metal to gain or lose $d$-electron count and this, in turn, is used to provide t…
Ultraviolet optical absorption, emission, and excitation spectra are presented for 14-MeV neutron-irradiated high-purity crystalline ${\mathrm{Al}}_{2}$${\mathrm{O}}_{3}$. Low-temperature polarized excitation spectra for the 3.8-eV luminescence correlated well with polarized absorption at 4.8 eV (both polarizations) a…
Experimental results are reported on S-state ions incorporated into PbFCl-type tetragonal single crystals. The spin Hamiltonian parameters of these ions are determined and correlated with structural and physico-chemical properties of the studied compounds. The experimental b 2 0 spin Hamiltonian parameters vary linear…
Abstract The synthesis of sterically hindered 1,1′, 3,3′‐tetraethylbenzimidazolotriazatrimethine cyanine dyes, their electron absorption spectra and that of their photo‐products (inverse photochromism) is described. Kinetic data of the thermally reversed reaction of the photo‐bleached compounds are given. The differen…
Crystals of a nearly one-dimensional salt, CsMn${\mathrm{Br}}_{3}$, which have been doped with trivalent neodymium, exhibit emissions from both ${\mathrm{Nd}}^{3+}$ and ${\mathrm{Mn}}^{2+}$. At room temperature the emission from ${\mathrm{Nd}}^{3+}$ is strikingly intense, much stronger than the ${\mathrm{Mn}}^{2+}$ em…
Abstract Six different segmented copolyether‐esters based on polybutyleneterephthalate as the hard and oligotetramethylene oxide glycols as the soft segments were studied. The weight fraction of the hard segments varied between 0.26 and 0.72 and the soft segment had an average molecular weight of either 1000 or 2000.…
Abstract A number of diacylperoxides, peroxydicarbonates, peresters and dialkylperoxides with various substituents were chosen to investigate their homolytic decomposition under pressures of up to 3000 bar and high temperatures of up to 200°C, discontinuously in steel autoclaves, in an optical high pressure cell and i…
We report results from x-ray experiments on mixtures of N-($p$-hexyloxybenzylidene)-$p$-aminobenzonitrile (HBAB) in N-$p$-cyanobenzylidene-$p$-$n$-octloxyaniline (CBOOA); very recent microscopic observations on mixtures of cyanohexyloxybiphenyl in cyanooctyloxy-biphenyl are in agreement with these results. The evidenc…
Abstract EPR parameters for atomic hydrogen in three nonequivalent special positions at the twofold axis of the monoclinic structure of brazilianite, formed by X-ray irradiation at room temperature, are reported. The g-factors are practically isotropic and close to the free electron value, but the hyperfine splittings…
Conference Article| December 01 1978 Conformational Stability of Lactate Dehydrogenase from Bacillus thermus-aquaticus SUSAN LAKATOS; SUSAN LAKATOS 1Department of Enzymology, Institute of Biochemistry, Hungarian Academy of Sciences, H-1502 Budapest, P.O.B. 7, Hungary Search for other works by this author on: This Site…
Conference Article| December 01 1978 Citrate Regulation of NADP+-Specific Isocitrate Dehydrogenase of Aspergillus niger MICHAEL MATTEY; MICHAEL MATTEY 1Department of Biochemistry, University of Strathclyde, Glasgow G4 0NR, Scotland, U.K. Search for other works by this author on: This Site PubMed Google Scholar ISABELL…
Detailed luminescence and lifetime data are presented for the mixed crystal system Al2xGa2(1−x)O3:Cr3+, where x=0, 0.02, 0.20, 0.35, 0.98, 1.0. The experimental data, obtained under broadband excitation at 77 K and 4 K, indicate that our pressure-grown microcrystalline samples all have the corundum (α-Al2O3) structure…