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 consequences of a simple, phenomenological, theory of lattice thermal conductivity with respect to the effect of point imperfections are summarized. The experimental results of Berman et al. on the effect of varying the concentration of ${\mathrm{Li}}^{6}$ on the conductivity of lithium fluoride are analyzed in de…
Radiation damage events at low and moderate energies (up to 400 ev) are studied by machine calculations in a model representing copper. Orbits of knock-on atoms are found and the resulting damaged configurations are observed to consist of interstitials and vacancies. Thresholds for producing permanently displaced atom…
Abstract The inability of polymer chains to deform the required amount within the time allowed by a stress‐to‐failure event results in brittle failure. Factors related to brittle behavior of films were investigated. By both conventional and novel testing techniques, stress–time–temperature relationships were studied t…
Abstract The literature reports that hydrolysis of cellulose under heterogeneous conditions proceeds by an initially rapid attack on the amorphous regions and then a much slower hydrolysis of the ordered regions or “crystallites.” During such hydrolysis, the degree of polymerization (D.P.) of cellulose initially decre…
Abstract An understanding of the formation of urethan foams involves consideration of the organic chemistry of the reactions leading to gas formation and molecular growth, the colloid chemistry of nucleation phenomena and bubble stability, and the rheology of the polymer system as it cures. Experimental data are not a…
The electrical properties of materials in the system lead‐barium niobate are described. Particularly useful materials are obtained when between 25 and 50 mole % of lead niobate is replaced by barium niobate. Materials with a 40 to 45 mole % replacement have permittivities of more than 1500 and radial electromechanical…
Scandium dihydride was prepared and studied. Scandium was outgassed at 800 deg C in a silica tube. The tube was cooled to room temperature and connected to a series of calibrated volumes containing purified hydrogen at slightly below atmospheric pressure. Pressures were indicated on a manometer read by a cathetometer…
Measurements of spin-lattice relaxation time in ruby have been made at 34 6 Gc/s by a pulse saturation method at temperatures from 1.4° to 90°K With weak concentrations the values for the first-order transitions (e.g. 22 msec at 4.2°K) are of the same order of magnitude as those reported at lower frequencies, and the…
The infrared spectrum of black carbon disulphide dispersed in a potassium bromide disk has been examined. The blackness and the infrared spectrum are consistent with its being a linear polymer, —(C==S.S) n .
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTThe Barium-Barium Hydride Phase System1David T. Peterson and M. IndigCite this: J. Am. Chem. Soc. 1960, 82, 21, 5645–5646Publication Date (Print):November 1, 1960Publication History Published online1 May 2002Published inissue 1 November 1960https://pubs.acs.org/doi/10.1021/j…
Abstract It has been confirmed by means of electron diffraction that lath‐shaped crystals of polyethylene are {110} reflection twins in which the chain molecules adopt a regularly folded conformation. The orientation and habit of the spiral terraces (or steps) which grow on the {001} faces of these crystals through th…
The microscopic shape of a solid-liquid interface has been examined theoretically for those growth conditions which give rise to a cellular morphology. The method of obtaining a general solution is set forth, and approximate treatments are used to compare the theoretical approach with experimental data. The variation…
Force constant, dissociation energy, and equilibrium internuclear distance in a sequence of similar diatomic molecules have been found to be related by the expression kere/D0=const. The applicability of this relationship has been shown for eighteen sequences of similar molecules. With the help of this relationship, th…
The triplet excited states of porphin are classified as either singly or doubly excited electron configurations. The latter are discussed in detail in terms of a circular box model with electron interaction plus a perturbation due to the actual molecular shape. The energy and intensity of the triplet-triplet transitio…
Crystalline cesium triborate, Cs20.3 B203, has been prepared and the structure determined.The crystals belong to the space group P212121, with unit-cell dimensions a=6.18, b=8.48, c-9.17 A.A complete set of atomic parameters has been determined from electron-density projections along the two shortest axes.The structur…
The dissolution of single crystals of undoped germanium in Superoxol etchant is shown to be very closely completely orientation-dependent by the applicability of recent theorems on crystal dissolution shapes. The results of the theory are outlined, and the method of application is described in detail.
The temperature dependence of the Debye temperature of aluminum, lead, and beta brass was determined by measuring the integrated intensity of a high angle x-ray diffraction peak from each of the materials as a function of temperature. This measured temperature dependence agrees well with the corresponding function obt…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTTHE GROWTH OF LARGE SINGLE CRYSTALS OF ZINC OXIDE1J. W. Nielsen and E. F. DearbornCite this: J. Phys. Chem. 1960, 64, 11, 1762–1763Publication Date (Print):November 1, 1960Publication History Published online1 May 2002Published inissue 1 November 1960https://pubs.acs.org/doi…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTThermogravimetric MeasurementsA. E. NewkirkCite this: Anal. Chem. 1960, 32, 12, 1558–1563Publication Date (Print):November 1, 1960Publication History Published online1 May 2002Published inissue 1 November 1960https://doi.org/10.1021/ac60168a006RIGHTS & PERMISSIONSArticle Vie…
Measurements have been made of the characteristic electron energy loss spectra of beryllium, antimony, bismuth, germanium, tin, cadmium, copper, platinum, lead and calcium using the reflection technique and with 750 eV and 1500 eV primary electrons. The spectra of each element were found to consist almost entirely of…