Materials Literature
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Abstract Crystal structure determinations of two metal‐ion complexes with noncyclic ionophores are reported: (i) CaCl 2 complex of N,N,N′,N′‐Tetrapropyl‐3,6‐dioxa‐octane diamide, space group Fddd, a = 14.659, b = 19.616, c = 33.173 Å; (ii) MnBr 2 complex of N,N,N′,N′‐Tetrapropyl‐1,2‐cyclohexylenedioxydiacetamide, spac…
Reversible photochromic reactions can be coupled to carrier-mediated transport processes in membranes to bring about the separation or concentration of selected permeants. Carbon monoxide has been pumped against of fourfold concentration gradient by differentially illuminating a hemoglobin membrane. The extent of conc…
The structural first-order phase transition of the layer structure (CP2H5NH3)2CdCl4 at 216 K is studied by single-crystal X-ray diffraction. The low-temperature phase (OLT) belongs to the space group Pcab, whereas the room-temperature phase (ORT) belongs to the space group Bmab. In both structures, the hydrogen atoms…
A new film-bulk method is used for the measurement of the depth distribution of current density and absorption of incident primary electrons penetrating into solid targets of Be, Al, Cu, and Au, As well the depth dependence of the generation of secondary electrons in the interior of the targets is determined experimen…
Energy distribution curves (EDC's) of photoelectrons emitted normal to the surface have been measured for the (0001) and (10\ifmmode\bar\else\textasciimacron\fi{}10) single crystal faces and for evaporated polycrystalline films of cobalt. Incident photon energies of 11.83, 16.85, and 21.22 eV were used. The EDC's of t…
The effect of hydrostatic pressure on the Raman-active ${A}_{g}$ and ${B}_{3g}$ modes in the IV-VI orthorhombic layer compounds GeS and GeSe is reported. The pressure coefficients and corresponding mode Gr\"uneisen parameters of the rigid-layer modes are found to be an order of magnitude larger than those of the rocks…
Using a percolation construction we evaluate the temperature dependence of the phonon-assisted dc hopping conductivity of a model appropriate to a class of anisotropic quasi-one-dimensional conductors in which the electronic states in the vicinity of the Fermi level are localized because of intrinsic and or extrinsic…
The relationship between the Mulliken electronegativities of the elements and the work functions of metals has been investigated, and it has been found that these two are equal. This investigation has been extended to binary nonmetals using a relationship proposed by Nethercot with good success so that a general proce…
The thermal conductivity and thermoelectric power of an inhomogeneous material subjected simultaneously to gradients of temperature and electric potential are accounted for in terms of an effective-medium theory as well as by numerical simulations in cubic networks with correlated bonds.
The complex dielectric constant $\ensuremath{\epsilon}(\ensuremath{\omega})={\ensuremath{\epsilon}}_{1}+i{\ensuremath{\epsilon}}_{2}$ for graphite is derived in the energy range 1 to 0.001 eV by Kramers-Kronig analysis of reflectance data with a suitable extrapolation of the curve to $R\ensuremath{\rightarrow}1$ for $…
Drift velocity for holes in high-purity Ge ($|{N}_{D}\ensuremath{-}{N}_{A}|<{10}^{11}$ ${\mathrm{cm}}^{\ensuremath{-}3}$) has been analyzed for a wide range of temperatures $8\ensuremath{\le}T\ensuremath{\le}220$ \ifmmode^\circ\else\textdegree\fi{}K and fields $1\ensuremath{\le}E\ensuremath{\le}{10}^{4}$ V/cm appli…
Raman spectra of vibrational excitations in graphite intercalated with alkali donor atoms have been obtained at room temperature in the backscattering configuration using argon ion laser excitation. Stage 1, 2, and 3 cesium donor compounds prepared from highly oriented pyrolytic graphite (HOPG) were studied as were st…
A new theory of lattice vibrations in amorphous silicon dioxide is presented in which the randomness of the solid is treated separately from its chemistry. The theory attributes all measurable properties of phonons in silica to the nearly crystalline nearest-neighbor geometry of the lattice and to the disruptive effec…
The optical absorption of the one-dimensional Hubbard model is calculated by three different methods. Linear chains of five atoms and rings of five and seven atoms containing four electrons are treated numerically. The infinite-chain problem is solved first in the $t$-matrix approximation of Lyo and Holstein. It is sh…
Many features of glasses below 1 K are explicable in terms of localized tunneling levels, for which a spin-$\frac{1}{2}$ analogy exists. Here we show that spectral diffusion, resulting from fluctuations in resonant frequency, is essential to our understanding of recent ultrasonic experiments. Our model involves a coup…
A calculation of the Van der Waals binding energy between layers of a hexagonal layered structure is presented. The results are used to estimate the interlayer binding energy of graphite, using measured mean and derived anisotropic polarisabilities. The agreement with experimentally measured binding energy is satisfac…
A 161 Dy Mossbauer study has been performed on the cubic equiatomic compound DyMg. From the value of the hyperfine parameters, the isomer shift in the intermetallic compounds of dysprosium and the magnetic properties of the heavy rare-earth-magnesium system are discussed.
Low-energy-electron diffraction $I\ensuremath{-}V$ spectra obtained from the clean, cooled $\mathrm{W}{001}(\sqrt{2}\ifmmode\times\else\texttimes\fi{}\sqrt{2})R45\ifmmode^\circ\else\textdegree\fi{}$ surface structure at 190 K display $2mm$ point-group symmetry, revealing a preferential orienting of equivalent domains.…
We find that certain cyano Schiff bases and cyanobiphenyls with alkyl or alkoxy end groups exhibiting a bilayer smectic-$A$ phase also exhibit a reentrant nematic phase at high pressure. A tentative model of the bilayer smectic phase held in place via the attractive interaction of the alkyl or alkoxy chains accounts f…
The ability of Saccharomyces cerevisiae NCYC 366 to adsorb polydimethylsiloxane (PDS), dispersed in an aqueous emulsion containing stearate emulsifiers and cellulose-based thickeners, is diminished after treatment with trypsin, KOH and HF; treatment with β-glucanase initially caused an increase in binding which dimini…