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The Alexander-Kaplan method is applied to analyse the E.S.R. spectra of symmetrical three-spin systems, undergoing fast, intermediate and slow rotational diffusion in nematic liquid crystals. Particular emphasis is given to the slow-motional region. The line shapes are calculated from a spin hamiltonian, which conside…
The Avcothane 51 elastomer, a member of a series of proprietary materials best characterized as polyurethane/poly(dialkylsiloxane) block copolymers, displays considerable hemocompatibility without any incorporated anticoagulants. In the form of intra-aortic balloons, the elastomer was implanted in several thousands of…
The rates of oxidative addition of methyl iodide to the comolexes [PtR2(bipy)][bipy = 2,2′-bipyridyl; R = Me, Ph, 4-XC6H4(X = F, Cl, Me, or OMe), and 3-XC6H4(X = F or OMe) have been studied.The second-order rate constants follow the series R = Me > 4-MeOC6H4 > 4-MeC6H4 > 3-MeOC6H4 > Ph > 4-FC6H4 > 4-ClC6H4 > 3-FC6H4,…
Neutron diffraction study was carried out on single crystals of the perovskite oxide SrFeO 3- x ( x =0.1). SrFeO 3- x ( x =0.1) has a proper screw spin structure with the propagation vector parallel to [111] direction and its Néel temperature is 118 K. The electron configuration of Fe 4+ (3 d 4 ) ion is close to the l…
Views Icon Views Article contents Figures & tables Video Audio Supplementary Data Peer Review Share Icon Share Twitter Facebook Reddit LinkedIn Tools Icon Tools Reprints and Permissions Cite Icon Cite Search Site Citation Russell J. Boyd; Electron density partitioning in atoms. J. Chem. Phys. 1 January 1977; 66 (1): 3…
A free-ion-model crystal-field calculation has been performed for YAl${\mathrm{O}}_{3}$:${\mathrm{Er}}^{3+}$. A free-ion calculation was done by fitting a free-ion Hamiltonian, which included Coulomb, spin-orbit, configuration, spin-spin, and spin-other-orbit interactions. The coefficients which gave the best least-sq…
Possible losses of trace elements during dehydration of marine zoological material with a high water content were studied by means of radioactive tracers, using the oyster Crassostrea gigas as an example. It is probable that no losses occurred with chromium, iron, manganese, cobalt and zinc, but serious losses of sele…
Analytical methods are given which enable one to describe geometrically layers of large curvature in a smectic phase. Dupin cyclides in focal domains are taken as examples. The curvature energy of focal domains is calculated. The difference between normal focal domains (built on an ellipse and an hyperbola), and parab…
The possibility of the smectic A to C phase transition is discussed, using a model based on the dipole-dipole interaction of the polar bonds of the molecules, which are supposed to rotate randomly around their long axis in both the A and C phases. Two different choices of the two-particle distribution function are use…
Thin gold films were vapor deposited onto KCl single crystals under a variety of substrate temperatures, residual gas pressures, and deposition rates. The films were subsequently examined by high‐resolution transmission‐electron microscopy. The use of the defocus contrast technique revealed a large number of small (10…
Abstract Significance of symmetry in representing real‐ and reciprocal‐space properties of a crystal and of its constituents is discussed in terms of symmetry eigenfunctions. The formation of the site‐symmetrized multipole expansion for the 32 crystal point symmetries is shown, and the mutual relations between the rea…
Abstract A computer program is described that permits the refinement of the static charge deformation in a flexible atom‐centered multipole expansion, together with positional and vibrational parameters, against X‐ray and neutron data. Other options allow for rigid‐body constraints on some or all of the atomic vibrati…
Abstract Shake‐up phenomena in a series of para ‐substituted polystyrenes have been studied by ESCA. Comparison with other spectroscopic data and with theoretical calculations within the sudden approximation, equivalent cores model, and CNDO SCF MO formalism identifies the shake‐up structures as arising predominantly…
Evidence is provided that silver zeolites can be used for the decomposition of water into hydrogen and oxygen; the process consists of a photochemically induced reduction of the zeolite, followed by an oxidative thermal desorption of hydrogen.
Permittivity, dielectric loss tangent, radial coupling coefficient, and radial frequency constant have been measured as a function of composition for pressure‐sintered Li. r Na 1‐x NbO 3 in the range 0.015≤x≤0.15. An anomaly in each of these properties when plotted as a function of composition is associated with a str…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTSynthesis of binary gold carbonyls, Au(CO)n (n = 1 or 2). Spectroscopic evidence for isocarbonyl(carbonyl)gold, a linkage isomer of bis(carbonyl)goldD. McIntosh and G. A. OzinCite this: Inorg. Chem. 1977, 16, 1, 51–59Publication Date (Print):January 1, 1977Publication Histor…
Because of their high symmetry, most of the silica polymorphs contain only a few nonequivalent Si–O distances. However, the structure of coesite contains two nonequivalent silicate tetrahedra, eight Si–O bonds, five Si–O–Si and twelve O–Si–O angles, thus making it an excellent candidate for testing Si–O bonding theory…
The interaction of a number of nitrogen containing molecules (NO, NH3 and N2H4) with copper has been investigated by electron spectroscopy. Nitric oxide is shown to be molecularly adsorbed in a linearly bonded configuration at 85 K; this adlayer is unstable above 120 K, resulting in an exclusively oxygen adlayer at 29…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTReductive coupling of adjacent ligands in a seven-coordinate molybdenum(II) isocyanide complexC. T. Lam, P. W. R. Corfield, and S. J. LippardCite this: J. Am. Chem. Soc. 1977, 99, 2, 617–618Publication Date (Print):January 1, 1977Publication History Published online1 May 200…
The temperature dependences of the second moments M2 of the proton magnetic resonance absorption spectra and of the proton spin–lattice relaxation times T1 of perovskite layer compounds (CnH2n+1NH3)2CdCl4 with n=1–3 and (NH3– (CH2)n–NH3) CdCl4 with n=2−5 have been studied together with the frequency dispersion of T1.…