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 Polyethylene of the linear, low‐pressure type has been crystallized under pressure (up to 5400 atm.) from the melt. Crystallization conditions of constant supercooling and constant cooling rates were employed. The resulting solid was analyzed at atmospheric pressure. In contrast to solution crystallization un…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTMagnetic Properties of Some High-Spin Complexes of Iron(II)W. A. Baker Jr. and H. M. BobonichCite this: Inorg. Chem. 1964, 3, 8, 1184–1188Publication Date (Print):August 1, 1964Publication History Published online1 May 2002Published inissue 1 August 1964https://pubs.acs.org/…
The total fraction of the current transmitted and its angular distribution have been measured when an electron beam is incident normally on evaporated films of aluminium, copper, silver and gold. The range of mass-thickness ρ x investigated was such that plural scattering prevailed in the thinnest, and diffusion condi…
Equations are derived relating the spin—rotation constants and magnetic shielding for any type of molecule. In general, the spin—rotation constants depend on the equilibrium nuclear positions and a second-order term involving the excited electronic states. The spin—rotation constants are interpreted by a localized the…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTAn X-Ray Diffraction Study of Nonplanar Carbanion StructuresCharles. Bugg, Robert. Desiderato, and Ronald L. SassCite this: J. Am. Chem. Soc. 1964, 86, 15, 3157Publication Date (Print):August 1, 1964Publication History Published online1 May 2002Published inissue 1 August 196…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTMechanistic Investigations of Porphyrin Syntheses. I. Preliminary Studies on ms-TetraphenylporphinAlan D. Adler, Frederick R. Longo, and William. ShergalisCite this: J. Am. Chem. Soc. 1964, 86, 15, 3145–3149Publication Date (Print):August 1, 1964Publication History Published…
CONTENTS I. Introduction 386 II. Two thermodynamic treatments of metastable states 386 III. The concept of the nucleus of a new phase 387 IV. Calculation of the work of formation of a new phase by means of thermodynamic potentials 388 V. The formation of a new phase under isobaric–isothermal conditions 389 VI. Limitin…
Abstract Graphite as deposited by cracking hydrocarbons around 2000 °C shows marked preferred orientation with consequent anisotropy, but still contains numerous structural defects. Procedures have been investigated for removing these by recrystallization around 3000 °C under a shearing stress, resulting from applying…
Abstract Transition metal complexes with configurations d4, d5, d6 and d7 are of two types—high-spin and low-spin— depending on the strength of the ligand field. Ligand field theory predicts that truly octahedral complexes ML6 could exist in which both types are in thermal equilibrium at ordinary temperatures, but no…
A complete ab initio approximate Hartree-Fock calculation has been carried out on the ${\mathrm{Mn}}_{2}$ molecule at three internuclear distances, $R=4.5, 5.0, \mathrm{and} 5.5 {a}_{0}$. The theory of the Heisenberg exchange interaction, applied in an earlier paper to the nitrogen molecule at large $R$, is used to id…
Monte Carlo calculations are applied to the problem of "hot" electron motion in metals, and measured values of attenuation length, $L$, are related to values of the mean free paths for electron-electron scattering ${l}_{e}$, and electron-phonon scattering ${l}_{p}$. Calculations are done for both specular and diffuse…
The study presented here includes experimental data obtained from three $n$-type and two $p$-type single-crystalline samples of PbTe. Measurements of the Hall coefficient, thermoelectric power, and electrical conductivity have been made between 77 and 300\ifmmode^\circ\else\textdegree\fi{}K, and infrared reflectivity…
The infrared reflection and transmission spectra of CaTi${\mathrm{O}}_{3}$, SrTi${\mathrm{O}}_{3}$, and PbTi${\mathrm{O}}_{3}$ have been measured from 4000 to 30 ${\mathrm{cm}}^{\ensuremath{-}1}$ at room temperature. The reflection data have been analyzed by means of a Kramers-Kronig method, from which the frequencies…
The variations with temperature of the elastic moduli in single crystals of hcp Ti, Zr, and Hf have been experimentally determined from 4\ifmmode^\circ\else\textdegree\fi{}K up to 1155\ifmmode^\circ\else\textdegree\fi{}K, using an ultrasonic wave interference technique. The ${c}_{11}$, ${c}_{33}$, and ${c}_{44}$ diffe…
The approximation is made that the dividing surface between a liquid and its vapor phase is a monomolecular layer, in which a molecule has a free volume larger than for an interior molecule and a potential energy less than for the latter. By introducing the approximation into the significant structure theory of liquid…
The effect of configuration interaction on the validity of the usual method of expanding the crystal field potential in terms of spherical harmonics is examined using second-order perturbation theory. It is found that for a configuration of equivalent electrons lN most mechanisms of configuration interaction lead to a…
The release of hydrogen atoms by a platinum surface in contact with molecular hydrogen occurs if there is oxygen in the system. In particular, it is sufficient that the oxygen be adsorbed at the surface of the metal.
The shell of the freeswimming veliger larval stage of the common North American oyster Crassostrea virginica (Gmelin, 1791) is composed of aragonite. This composition contrasts with that of the adult shell, which is composed mainly of calcite, the rhombohedral allomorph of calcium carbonate, and minor amounts of arago…
Abstract Several features of the pyrolysis of acetylene in the temperature range 500 to 1000 °C suggest that the underlying mechanism is the same as that in operation at both lower and higher temperatures. Thus the rate of consumption of acetylene obeys a second-order kinetic law and is little affected by additions of…
The Overhauser shift of the electron spin resonance due to the natural nuclear polarization at liquidhelium temperatures has been used to measure the conduction-electron density at the nuclei in $n$-type InSb. The results are: ${|\ensuremath{\psi}({R}_{\mathrm{In}})|}^{2}=(9.35\ifmmode\pm\else\textpm\fi{}1)\ifmmode\ti…