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。
A simple and practical viscometrical method for monitoring the progress of condensation polymerization reactions was investigated. It consisted of following the reaction mixture capillary flow time as a function of molar ratio of the reacting monomers in a polymerization reaction performed by gradual addition of terep…
An empirical formula for gamma-ray buildup factors in two-layer shields is proposed. The values of the parameters are given for the formula when fitted to the dose buildup factors, calculated by the invariant imbedding method, for normally incident gamma rays penetrating two-layer shields comprised of combinations of…
Kaolinite undergoes structural transformation on heating. X‐ray photographs reveal the existence of a spinel‐type phase when kaolin is heated at 980°C. The kaolinite decomposes into a spinel phase with the expulsion of silica. A controversy arises as to whether the spinel phase is γ‐Al 2 O 3 or Si‐Al spinel. Calculati…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTDependence of magnetic properties on structure in the systems nickel(II) molybdate(VI) and cobalt(II) molybdate(VI)K. Sieber, R. Kershaw, K. Dwight, and A. WoldCite this: Inorg. Chem. 1983, 22, 19, 2667–2669Publication Date (Print):September 1, 1983Publication History Publis…
Abstract Monodispersed poly(4‐bromostyrenes) (PBs) and their block copolymers with styrene, isoprene, and 3‐methylbutene were prepared and characterized by GPC and NMR. Polystyryl and α‐methylstyryl carbanions act as effective initiators of the anionic polymerization of Bs in THF. The undersirable side reactions, due…
We report magnetostriction measurements on a single crystal of Tb.27Dy.73Fe2. Length changes parallel and perpendicular to a 111 direction were measured from 298 to 3.1K in magnetic fields from zero to 25kOe. The λ vs H curves show saturation at low fields above 280K; below 280K λ becomes progressively more difficult…
The N-I transition temperatures for a range of 4-propyl 1-monoesters and several 1,4-diesters of cubane, bicyclo(2.2.2)octane, cydohexane and benzene have been determined. The differences between the values for the monoesters and diesters of each system and between those for the various ring systems for the mono- and…
Several optical tests were employed to demonstrate twinning in raphides from 10 species in the family Vitaceae and one species in the Araceae. Scanning electron microscopy revealed that twin raphides differ from the reported shape of twin styloids and that raphides of the Vitaceae are "barbed" along two sides. A model…
Selfsputtering yields of molybdenum and tungsten have been measured by the weight change method in the energy range between 0.1 keV and 10 keV at normal incidence. Measured yields are compared with two different universal empirical formulae proposed to predict the energy dependence of the sputtering yield and it is fo…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTSyntheses and structures of a novel series of tetrathiolene clusters: (.eta.5-C5H5)2Fe2(C10Cl4S4)(C10Cl4S3), (.eta.5-C5H5)2Co2(C10Cl4S4), and (.eta.5-C5H5)2Ni2(C10Cl4S4)Boon K. Teo, V. Bakirtzis, and P. A. Snyder-RobinsonCite this: J. Am. Chem. Soc. 1983, 105, 20, 6330–6332P…
Analytical spatial yield spectrum approach has been applied to calculate the electron flux, volume excitation, and ionization rates for monoenergetic electrons incident on the earth's atmosphere. The results have been compared with the previous model calculations of Mantas and Walker (1976) and Banks et al. (1974).
Abstract A model of the TlGaSe 2 ‐I band structure of the monoclinic modification is proposed. The monoclinic modification of TlGaSe 2 ‐I is considered as a deformed tetragonal one. The band structure of the metastable tetragonal modification of TlGaSe 2 ‐II is calculated by the pseudopotential method. The irreducible…
ABSTRACT Microtubule involvement in diatom valve symmetry and pattern formation was investigated using cells synchronized subsequent to mitosis and cytokinesis but prior to cell wall formation. Two analog drug pairs, each consisting of an active and an inactive microtubule drug, were used to distinguish inhibitory eff…
Abstract Many soils which morphologically appear to be Spodosols do not meet the chemical requirements for the spodic horizon. The purpose of this study was to develop new chemical criteria for defining the spodic horizon. New chemical criteria were developed using samples from 18 pedons and were further tested with s…
The periodic switching between two feed compositions to a gradientless reactor has been found to increase significantly the average reaction rate compared with steady stale operation. Another advantage of periodic feed switching, which has not been fully exploited in catalyst studies is in kinetic model discrimination…
Single crystals of the Fe–Cr–Co alloys without and with 3% Mo were prepared by a recrystallization process. The microstructures and the magnetic properties of 〈100〉, 〈110〉, and 〈111〉 single crystals were investigated after the heat treatment in the ridge region of the miscibility gap. The magnetic properties of the Fe…
Pacific Northwest Laboratory conducted a research program to measure uranium and thorium levels in excreta of uranium mill crushermen who are routinely exposed to airborne uranium ore dust. The purpose of this work was to determine whether 230Th was preferentially retained in the body over either 234U or 238U. Urine a…
Abstract The reaction products of gaseous ZrCl4 with ammonia were ZrCl4·2NH3 at 300 °C; ZrCl4·2NH3, ZrClN, and NH4Cl at 350–700 °C; ZrCl4·2NH3, ZrClN, ZrNx, Zr3N4, and NH4Cl at 750 °C; ZrClN, ZrNx, Zr3N4, and NH4Cl at 800–950 °C: ZrNx, Zr3N4, and NH4Cl at 1000–1050 °C; and ZrNx, NH4Cl, and HCl at 1100–1400 °C. The N/Z…
Zirconium pyrovanadate powders prepared from solution precipitation and by solid‐state reaction were hot pressed below 800°C. Unit cell parameter and thermal expansion were found to have a negative slope above 150°C, attributed to flexing of the bond angles in the structure. Thermal expansion coefficient determined wa…
Abstract 8-Oxabicyclo[3.2.1]octan-3-one derivatives serve as excellent models that elucidate factors controlling the reactivities and selectivities in the Baeyer-Villiger oxidation. The regioselectivity of the oxidation with trifluoroperacetic acid is markedly affected by the electronic properties of substituents at p…