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。
The ${F}^{\ensuremath{'}}$ band has been produced and measured in the following alkali halides: NaCl, KCl, KBr, KI, RbCl, RbI, CsBr, and CsI. Additively colored samples were optically bleached in the $F$ band at an optimum temperature to produce a maximum $F$-to-${F}^{\ensuremath{'}}$ conversion. The observed spectra…
Polarized far-infrared spectra of aliphatic polyesters [–(CH2)z–CO–O–O]n with z = 1, 2, and 5 (z = 4, nonpolarized) and α-polyamide (nylon 6 and its N-deuteroderivative) have been measured in the region up to 80 cm−1. All these polymers have essentially planar zigzag conformations. The normal vibrations of these polym…
Measurements of the 57Fe Mössbauer spectrum of phthalocyanine iron(II) made at 4.2° and 100°K, with the sample in applied magnetic fields of 30 kOe, show that the electric field gradient at the iron nucleus is of positive sign and that there is no large asymmetry in the electric-field-gradient tensor. The major axis o…
The reflectivity of single-crystal sodium nitrite has been measured as a function of temperature and crystallographic orientation over a wavelength region which spans all the eight infrared-active normal modes. The temperature-dependent dielectric response functions and oscillator parameters have been obtained both by…
Photoluminescence studies were made at liquid-helium temperatures of epitaxial GaAs with ionized-impurity concentrations \ensuremath{\lesssim}${10}^{15}$ ${\mathrm{cm}}^{\ensuremath{-}3}$. Narrow linewidths at half-height were achieved by using material of high purity and perfection, by using low intensities of illumi…
Crystals of ${\mathrm{Ti}}_{2}$${\mathrm{O}}_{3}$ of relatively high purity or doped with various impurities have been grown by the Czochralski method. The semiconductor-metal transition commenced at 435\ifmmode^\circ\else\textdegree\fi{}K with a change of resistivity from 9\ifmmode\times\else\texttimes\fi{}${10}^{\en…
The magnetic properties of phthalocyanine iron (II) have been investigated in the temperature ranges 1.25°–20°K and 100°–300°K. Between 100° and 300°K the magnetic susceptibility obeys the Curie–Weiss law accurately, but the measured value of μeff at 25°C is 3.71 μB, which is intermediate between the theoretical spin-…
A pulsed magnetic-resonance spectrometer is used to measure pure NQR frequencies and relaxation times of the $^{35}\mathrm{Cl}$ and $^{37}\mathrm{Cl}$ nuclei in powdered samples of ${\mathrm{K}}_{2}$Pt${\mathrm{Cl}}_{6}$ over the temperature range $6<T<490\ifmmode^\circ\else\textdegree\fi{}$K. The ratio of frequ…
The experimental dependence of the magnetization on temperature and composition is presented for ${\mathrm{Ga}}_{2\ensuremath{-}x}{\mathrm{Fe}}_{x}{\mathrm{O}}_{3}$. Interpretation is based on a three-sublattice model, giving the $x$ dependence of the iron occupation of the various sites, the variation of the Curie te…
In their paraelectric phases, SrTi${\mathrm{O}}_{3}$ and KTa${\mathrm{O}}_{3}$ crystallize in the cubic perovskite structure (space group ${{O}_{h}}^{1}$) in which the first-order Raman effect is forbidden. We discuss here experiments in which first order Raman scattering has been induced by the application of an exte…
Room-temperature Raman spectra of high-quality single-domain BaTi${\mathrm{O}}_{3}$ crystals are reported. The frequencies of the Raman-active long-wavelength optical phonons are determined and shown to be in reasonable agreement with the Lyddane-Sachs-Teller (LST) relation as well as infrared reflectivity data. The e…
A systematic study has been made of multiphonon orbit-lattice relaxation of excited states of rare-earth ions in crystals. By measuring both excited-state fluorescence lifetimes and multiphonon relaxation quantum efficiencies, pure multiphonon transition rates were determined for the following set of crystals: (1) La$…
Photoemission quantum yield and energy distribution curves have been measured for V${\mathrm{O}}_{2}$ in the tetragonal (100\ifmmode^\circ\else\textdegree\fi{}C) and monoclinic (25\ifmmode^\circ\else\textdegree\fi{}C) phases over the photon energy range from 7 to 11.5 eV. The V${\mathrm{O}}_{2}$ studied was a polycrys…
THE EFFECT OF NEGATIVE ADSORPTION ON THE FILTRATE COMPOSITION OF CLAY SUSPENSIONS AND PASTES WAS STUDIED. A DRYING-OUT HOMOIONIC MONTMORILLONITIC SUSPENSION WAS STUDIED THEORETICALLY AND EXPERIMENTALLY. THE RELATIONSHIPS BETWEEN THE WATER CONTENT OF THE SUSPENSION AND THE COMPOSITION OF THE FILTRATE WERE STUDIED BY US…
The absorption due to F centers in x-irradiated KBr and NaBr has been measured over a wide range of temperatures from 4 to 370°K. In NaBr (which is exceedingly difficult to color) there is also formed a well-isolated M band without the usual difficulty of overlapping R bands and so the temperature dependence of the sh…
In order to determine the conditions under which core spray cooling can be effective after loss of coolant accident, spray cooling experiments have been conducted on a heater assembly at low heat fluxes corresponding to the decay heat following a reactor shut-down. A series of tests have been made at atmospheric press…
A study of the mode of inhibition of RNase by bentonite showed that the inactivation of the enzyme could not be attributed solely to an ion-exchange effect as previously postulated. Vermiculite, which is a clay with higher cation capacity than bentonite, showed very little inactivation of RNase. The spatial arrangemen…
This study was designed to determine if the skinfold measurements on an exercised arm would decrease as a result of regular weight training with that arm. Thirty-two subjects completed three sets of 7-RM curls and three sets of 7-RM triceps extensions on either a daily or an alternate day schedule for a period of 6 we…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTEnthalpy of formation of neptunium dioxideElmer J. Huber and Charles E. HolleyCite this: J. Chem. Eng. Data 1968, 13, 4, 545–546Publication Date (Print):October 1, 1968Publication History Published online1 May 2002Published inissue 1 October 1968https://pubs.acs.org/doi/10.1…
Cottrell atmospheres modulate the solute concentration of alloys and lead to fluctuations in phonon velocity essentially proportional to the dislocation strain field. Normally one regards point defects as ineffective in scattering phonons at the very low temperatures when the thermal resistance due to dislocations is…