Materials Literature
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Abstract The morphology of linear polyethylene crystallized under pressures up to 5300 atm. has been investigated. Electron micrographs of fracture surfaces obtained from these samples show that the majority of the polymer, at the highest pressures, crystallizes in the form of extended chain lamellae which can be as t…
SUMMARY The structure of the galactohinase in Escherichia coli has been analyzed with the aim of defining the size of its structural gene. To that end the molecular weight, amino acid composition, number of tryptic peptides, and amino-terminal residues of this protein were determined. The results indicate that this ga…
A number of programs for facilitating the indexing of powder patterns, based essentially on trial-and-error methods, have been constructed for the electronic computers BESK and Facit EDB. The methods are efficient also for the analysis of powder patterns in which lines are missing either by accident or because of tran…
The photographic study of X-ray diffuse scattering from a single crystal was made in order to determine the rotational disorder of NO 3 groups above the critical temperature 275°C. The rounded diffuse maxima which appear at the positions of super-lattice reflections of the ordered lattice are identified with those due…
The development of insolubility in proteins exposed to ionizing radiation has been widely studied as a measure of molecular aggregation, although the extent and nature of the bonding involved is still a matter of speculation (1). In general, such studies have been concerned with soluble proteins, either in solution or…
The work treats the subject of power produced by cycling a ferromagnetic material thermally through a range of temperatures such that its magnetization changes appreciably and of utilizing the change of magnetization and its interaction with a magnetic field. Thermodynamically, an appropriate cycle to make this form o…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTKinetics of Absorption of Cardon Dioxide in Monoethanolamine Solutions at Short Contact TimesJ. K. A. ClarkeCite this: Ind. Eng. Chem. Fundamen. 1964, 3, 3, 239–245Publication Date (Print):August 1, 1964Publication History Published online1 May 2002Published inissue 1 August…
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…