Materials Literature
按标题、摘要、年份、主题和来源检索公开元数据。结果保留作者、摘要、分类与原始来源链接。
Abstract Durch Reduktion der Methoxycarbonylgruppen des Mesoporphyrin‐dimethylesters ( 4a ) wird das bisher unbekannte 1.3.5.8‐Tetramethyl‐2.4‐diäthyl‐6.7‐dipropyl‐porphin ( 5c ) erhalten. 5c läßt sich wie Octaäthyloporphin ( 7a ) als Kupferkomplex mit Hilfe der Vilsmeier‐Reaktion an einem meso ‐Kohlenstoffatom formyl…
Abstract A detailed analytical and kinetic study of the thermal decomposition of monosilane in the temperature range 375 to 430 °C and the initial pressure range 35 to 230 mmHg has been conducted. The gaseous products in the very early stages of the reaction are hydrogen, disilane and trisilane. In addition, later in…
Abstract The frequencies of the normal modes of vibration of lead telluride propagating in certain symmetric directions have been determined by inelastic neutron scattering techniques. The results have been used to deduce the parameters of rigid ion models and of shell models for the interatomic forces. The latter mod…
The Brillouin scattering spectra of crystalline quartz, fused quartz and Pyrex glass have been observed. The crystalline quartz spectrum contains three doublets corresponding to one longitudinal and two transverse acoustic modes, whereas the spectra of used quartz and Pyrex glass have one longitudinal and one transver…
The optical spectrum of Re4+(5d3) has been studied at 4.2°K in single crystals of K2PtCl6 and Cs2ZrCl6. The spectrum is characterized by extremely narrow lines in the region from 8500 to 36 000 cm−1. Vibrational structure is observed which is assigned to the odd modes of the ReCl62− complex. A crystal-field analysis o…
Single crystals of potassium sulfamate, KNH 2 SO 3 , enriched in the isotope 15 N, were irradiated, and examined at 77° K by electron spin resonance. Two intermediates, neither of which are present on examination at 300 °K, have been identified as NH 2 and NH 2 SO 3 . A possible radiolysis mechanism is discussed.
The magnetic susceptibilities of the monophosphides of V, Cr, Fe, and Co have been measured from 4.2\ifmmode^\circ\else\textdegree\fi{}K to room temperature. They were all found to be weakly paramagnetic. The previously reported metamagnetic transition in the MnP was confirmed, whereas none of the other compounds exhi…
First-order and second-order (in strain) magnetoelastic effects in yttrium iron garnet (YIG) have been studied using a pulsed ultrasonic technique and have been interpreted using finite-deformation magnetoelastic theory. Small-amplitude plane-wave modes in 100>, 110>, and 111> directions in uniformly magnetiz…
We have constructed to high order ($l=30$) all the linear combinations of spherical harmonics which transform as the identity representation of the full cubic group ${O}_{h}$. These are used with Mueller's inversion scheme to obtain the radius vectors of the palladium $s$-band surface from the de Haas-van Alphen areas…
The relative strengths of the hydrogen bonds in kaolinite-alkali salt-water systems control kaolinite-salt interactions. A new technique for intercalation results in formation of a kaolinite-salt complex free of excess salt.
A mechanism for vacancy generation in perfect crystals is proposed in which it is assumed that the progenitor for color-center formation is a dissociating $X_{2}^{}{}_{}{}^{=*}$ (excited) molecule: if this molecule is initially created, or subsequently placed, in an excited vibronic, predissociative, or repulsive stat…
The thermoluminescence (TL) of semiconducting diamonds was found to be composed of blue-emitting (at 150 and 260\ifmmode^\circ\else\textdegree\fi{}K) and red-emitting peaks (at 175 and 285\ifmmode^\circ\else\textdegree\fi{}K). The red peaks could be excited by light of wavelengths up to about 650 m\ensuremath{\mu} (1.…
A variety of phonon-gas phenomena in nonmetals are discussed in a unified manner using a set of macroscopic equations developed from the solution of the linearized phonon Boltzmann equation. This set of macroscopic equations, appropriate for the description of a low-temperature phonon gas, is solved for a cylindrical…
The ionic thermoconductivity (ITC) method, consisting of the study of the thermally activated release of dielectric polarization, is studied in great detail in alkali halide crystals. The (divalent metal ion, cation vacancy) dipoles give rise to an ITC band below 0\ifmmode^\circ\else\textdegree\fi{}C, whose area is pr…
The linearized Boltzmann equation for the pure phonon field may be solved formally in terms of the eigenvectors of the normal-process collision operator. This representation is particularly convenient as a basis for solutions, since in the isotropic dispersionless case the temperature deviation $\ensuremath{\delta}T$…
It is reported that a hitherto unexplained optical transition in ZnTe is due to oxygen substituting isoelectronically for Te. A classification of isoelectronic traps into isoelectronic donors and acceptors is made. One striking difference between these two classes is apparent in the phonon sidebands of the $J=1$ and $…
Magnetization curves from $T=0.15$\ifmmode^\circ\else\textdegree\fi{}K to ${T}_{c}$ have been measured for two specimens of semiconducting SrTi${\mathrm{O}}_{3}$ of electron density about ${10}^{20}$ ${\mathrm{cm}}^{\ensuremath{-}3}$. Magnetic hysteresis was observed in each case. The temperature dependences of the fi…
A comprehensive theoretical expression for the spin-lattice relaxation time in the rotating frame ${T}_{1\ensuremath{\rho}}$ is derived for the case of weak collisions. Starting from the laboratory-frame dipolar Hamiltonian and retaining both secular and nonsecular terms, the doubly-rotating-frame Hamiltonian is deter…
This paper represents an attempt to estimate the ionic contributions to the ground-state splitting of the trivalent gadolinium ion in a lanthanum ethyl sulfate lattice. The energy levels of the $4{f}^{7}$ configuration are calculated and compared with those observed experimentally. The calculated ground-state $g$ fact…
Abstract The official method for iodine in iodized salt, 31.064–31.067, was studied to determine interference from sodium thiosulfate added as a stabilizing agent; no interference was found. The present official method for iodine in iodized salt is reliable, and study of methods should be discontinued.