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We describe the excess Raman intensity recently observed by Winterling in vitreous silica for frequency shifts $\ensuremath{\omega}<20$ ${\mathrm{cm}}^{\ensuremath{-}1}$ in terms of structural relaxation of defects, which can have two distinct states of polarizability differing by an amount $\ensuremath{\Delta}\ens…
The phonon dispersion relation of the one-dimensional conductor, deuterated tetrathiafulvalene-tetracyanoquinodimethane (TTF-TCNQ), has been studied by inelastic neutron scattering over a temperature range of 60-300 K. Acoustic phonons propagating along the chain direction (the monoclinic ${b}^{*}$ direction) are stud…
We have measured the second and third order hyperpolarizabilities β and γ using the technique of electric field induced second harmonic generation in a variety of weakly associating (e.g., nitrobenzene–benzene) and strongly associating (e.g., water–methanol) liquid mixtures. These experiments are shown to yield intere…
Electrical field dependence of the dielectric constant in KTaO 3 has been measured under the bias field up to 15 kV/cm and in the temperature range between 300 K and 4.2 K. Characteristics of the induced polarization as functions of electric field and of temperature were obtained. A hysteresis phenomenon in the biasin…
We have calculated the effect on the surface-plasmon-polariton dispersion of a space-charge layer at a semiconductor surface, representing it by a dielectric function $\ensuremath{\epsilon}(\ensuremath{\omega})$ that has an exponentially varying part with a $\frac{1}{e}$ decay depth of the order of the layer thickness…
A paramagnetic centre having spin S=2 and C 2 symmetry has been detected in natural amethyst crystals. The only ESR transition observed was the Delta M=+or-4 transition between the lowest two energy levels M=+or-2. Line position measurements at 35 GHz and 16 GHz gave the g-tensor principal value for the C 2 direction…
The rate constant for the catalytic transfer of the active-site PO3 group from rabbit muscle phosphoglucomutase to the hydroxyl group of a water molecule is about 3 x 10(-8) s-1 under optimal reaction conditions, but in the absence of the normal substrate, viz., at pH 7.5 and 30 degrees C, in the presence of saturatin…
A new type of wave propagation in pure metals in a magnetic field is reported. This mode is analogous to cyclotron waves but is carried by the spin of conduction electrons. Oscillations in the microwave transmission spectra of copper and gold foils with ferromagnetic layers deposited onto them are attributed to these…
A new compound having the same composition as zircon, ZrSiO 4 , but differing from it in its structure has been obtained by heating zircon particles to a temperature of 5000 to 10000°K. According to X-ray powder diffraction data the structure and within limits of error also the unit-cell dimensions are identical with…
A generic relationship exists between lamellar mesophases (smectics A and C), formed by non-amphiphilic mesogens with lath-like molecules and "fused" lamellar mesophases, G (with or without solvents), formed by amphiphilic mesogens. A second generic relationship occurs between non-amphiphilic nematic mesophases and tw…
Abstract A simple, automated colorimetric method for determining oxalic acid in plant material is based on the quantitative reduction in colour of a zirconium/3,4‐dihydroxyazobenzene‐2′‐carboxylic acid complex by microgram quantities of oxalic acid. It is suitable for use over a wide range of oxalic acid concentration…
Summary On calcareous micaschists in the northern Adula Region, Switzerland, brown soils are formed under grasses and herbs at altitudes below 2000 m. Podzols occur below Ericaceae below 2000 m and are formed irrespective of vegetation above this altitude. Calcimorphic soils are not found. Brown soils have a stable cl…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTAmino acid-substituted iron porphyrins. 2. Thermodynamic studies of ligand bindingH. Goff and L. O. MorganCite this: Inorg. Chem. 1976, 15, 9, 2069–2076Publication Date (Print):September 1, 1976Publication History Published online1 May 2002Published inissue 1 September 1976h…
Abstract Interlanthanide perovskites CeTmO 3 , CeYbO 3 , CeLuO 3 , PrYbO 3 , PrLuO 3 , and Ce Ln O 3 solid solutions have been prepared by cofusion techniques. Thermal stability and the optical properties of these materials have been investigated. A very important nephelauxetic effect ( ΔE = 3600 cm −1 ) is observed.…
Extensive experimental comparisons of calorimetric and ionometric measurements have been made that cover a broader range of electron energies and depths in graphite than previously reported. Electron beams of 15, 20, 25, 30, 40, and 50 MeV were used. Calorimetric absorbed-dose measurements and ionometric specific-char…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTComplexation of tetra-.mu.-carboxylato-dirhodium(II) with imidazoleK. Das and J. L. BearCite this: Inorg. Chem. 1976, 15, 9, 2093–2095Publication Date (Print):September 1, 1976Publication History Published online1 May 2002Published inissue 1 September 1976https://pubs.acs.or…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTA symmetrical diazaditwistane. 2,9-Dicyano-5,11-dimethyl-5,11-diazatetracyclo[6.2.2.02,7.04,9]dodecaneJan Ten Broeke, Alan W. Douglas, and Edward J. J. GrabowskiCite this: J. Org. Chem. 1976, 41, 19, 3159–3163Publication Date (Print):September 1, 1976Publication History Publ…
Abstract The EPR spectra of three different Cu 2+ centres and the spectrum of the radiation hole centre in single crystals of anatase are investigated. The constants of the spin‐Hamiltonians for all the spectra and the ground state wave functions are obtained. The conditions of incorporation into the crystal, the site…
Abstract The characteristic ferroelectric dispersion of the complex dielectric constant of AgNa(NO 2 ) 2 is measured in a wide temperature range enclosing the transition point. It can be well described by a Debye monodispersive process except for a small temperature intervall around T c . The relaxation strength obeys…
All single phase regions (compounds and solid solutions) in the system were activated with 0.01 mole percent (m/o) Ce 3+ (with equimolar amounts of Li + , Na + , or K + added to compensate charges) and the resulting ultraviolet excitation and emission spectra were characterized. Brightest phosphors were obtained from…