Materials Literature
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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…
The chemical shifts of the Ge 3d, 3p 3/2,1/2 and Se 3d, 3p 3/2,1/2 photoelectron lines were measured for the amorphous Ge–Se system and those of the Ge photoelectron lines are corrected for Auger parameter shifts. According to the valence shell potential model, the ratio of the chemical shift in the amorphous Ge–Se sy…
A phenomenological model has been derived for thermally stimulated open-circuit current measured on negatively charged polytetrafluoroethylene electret film. The model is based on trap controlled release of negative charge carriers using approximations justified by thermally stimulated current and mean charge depth re…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTCatalytic decomposition of gaseous sulfur trioxideR. D. Brittain and D. L. HildenbrandCite this: J. Phys. Chem. 1983, 87, 19, 3713–3717Publication Date (Print):September 1, 1983Publication History Published online1 May 2002Published inissue 1 September 1983https://pubs.acs.o…
An experimental study was made on the collapse of a gas bubble attached to a solid wall by a shock wave. The collapse process of the bubble and the induced impact wall pressure were measured simultaneously by means of a high speed camera and a pressure transducer, respectively. Consequently, it was found that the impa…
Magnetic properties of iron nitride particles prepared with reactive gas evaporation method were investigated. Major products for higher NH3gas pressure region is γ'Fe4N and αFe. For lower pressure region αFe was produced, which was oxidized to Fe3O4after exposure to air. It is found that particles consist of γ'Fe4N a…
Stress transmission through the compact, die wall friction, and the radial/axial stress ratio were investigated using a spray‐dried alumina powder containing 2.3% polyvinyl alcohol binder, stored at 15, 55, or 92% rh, and an unlubricated/lubricated steel die for pressing. Stress transmission was enhanced by lubricatin…
The high pressure phase transition of cinnabar (α-HgS) was studied by energy dispersive x-ray diffraction using a synchrotron x-ray source. The cinnabar crystal structure was found to transform to the sodium–chloride structure at about 130 kbar. The lattice parameter of the new phase was determined to be 5.070±0.005 A…