Materials Literature
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Clothing adds resistance to heat exchange between the wearer and the environment. If clothing-specific heat exchange coefficients are known, a combined rational/empirical approach can be used to describe thermal exchange between clothed humans and the environment. However, during exercise these coefficients--typically…
The periplasmic [Fe] hydrogenase from the sulfate-reducing bacterium Desulfovibrio vulgaris (Hildenborough) DSM 8303 was found to be regulated by ferrous iron availability. During growth with 5 ppm of iron, the enzyme derepressed and the specific activity increased approximately fourfold, whereas the presence of 100 p…
Poly(ADP-ribose) glycohydrolase, extensively purified to homogeneity from nuclei of human placenta, is composed of a single polypeptide with a molecular mass of 71,000 daltons on sodium dodecyl sulfate-polyacrylamide gel. Judging from its physico-chemical and catalytic properties, the enzyme is similar to the nuclear…
Abstract The crystal structure of Sr 3 (VO 4 ) 2 has been refined using X-ray single-crystal diffractometry. Sr 3 (VO 4 ) 2 crystallizes in the space group R [unk] m (No. 166) with cell dimensions (hexagonal system): a = 5.619(1) Å, c = 20.100(4) Å, Z = 3. The crystal structure consists of a three-dimensional arrangem…
A silver-gold compound metal island film prepared by using a two-step evaporation method is demonstrated for the first time. Silver and gold islands have been completely alloyed by heating the film at 300 °C. The resonance wavelength of the compound metal island film exists between those of pure silver and pure gold i…
We report excited state absorption (ESA) in a CaWO4 under excimer laser excitation (308 nm). The ESA spectrum proves to be very broad and intense. We calculate the stimulated emission cross-section and show that it is at least one order of magnitude smaller than the broad-band ESA cross-section. This precludes laser a…
Glass formation and stability of calcium aluminate‐based glasses were assessed, qualitatively, by changing melt volumes and cooling rates. Stable glasses, obtained through the addition of sodium, barium, and strontium to the binary system, were investigated in detail. Glass stability was evaluated via DTA analysis. Th…
The split Hopkinson pressure bar was used to study the failure of a high‐strength alumina at strain rates on the order of 10 3 s ‐1 . There appears to be a critical strain rate above which the traditional method of using the transmitter bar signal to calculate the stress in the specimen is no longer valid. To compute…
Abstract Recent mathematical approximations of ϕ(ρz), the depth distribution of electron‐excited x‐rays, have opened up the possibility of accurate quantitative analysis of thin‐film specimens by electron beam techniques. This method has been used extensively in electron probe microanalysis. This paper demonstrates qu…
Measurements of pigment triplet-triplet absorption, pigment phosphorescence and photosensitized singlet oxygen luminescence were carried out on solutions containing monomeric bacteriochlorophylls (Bchl) c and d, isolated from green photosynthetic bacteria, and their magnesium-free and farnesyl-free analogs. The energi…
Abstract A study has been made on the graft copolymers obtained by radiation‐induced grafting of acrylic acid onto poly(tetrafluoroethylene‐ethylene) (ET) films. The conversion of the graft copolymer into metal acrylate copolymer complex was carried out by treatment with different metal salts. Such a prepared graft co…
Dielectric properties such as the permittivity, dielectric loss tangent and spontaneous polarization of highly ordered perovskite Pb(Yb1/2Ta1/2)O3 (PYT) compound which were prepared through the wolframite phase oxide were investigated. A dielectric anomaly which is characterized by a slight dielectric dispersion was f…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTCoupling of (amino)alkylchlorosilanes with lithium: new access to symmetrical di- and tetrafunctional alkyldisilanesKohei Tamao, Atsushi Kawachi, and Yoshihiko ItoCite this: Organometallics 1993, 12, 2, 580–582Publication Date (Print):February 1, 1993Publication History Publ…
The surface structure of a model system was measured in real space by atomic force and optical microscopies, and compared with that obtained from measurements in reciprocal space by x-ray reflectivity and off-specular scattering at grazing incidence. Experiments were performed on films of symmetric diblock copolymers…
Abstract The results of the Rietveld analysis of X-ray powder diffraction data for title compounds show that the space group for (CH3NH3)3Bi2Cl9 is Pnma with Z = 4 and its lattice constants are a = 2040.6, b = 770.0, c = 1324.6 pm. It consists of one–dimensional double chains of Bi2Cl93− polyanions. The space group fo…
The formation of ferroelectric domains in the smectic C* (SmC*) phase of ferroelectric liquid crystals with considerable high spontaneous polarization is observed using electrooptical methods. The temperature dependence of the corresponding domain modes DB (bulk) and DS (surface) is studied by dielectric spectroscopy.…
The emission spectra of [Pt(L)(CN)2] (L = 4,7-diphenyl-1,-10-phenanthrollne or 4,4′-di-tert-butyl-2,2′-blpyrldlne) Immobilized in silicone rubber are concentration dependent. At low concentrations of platinum complex a single emission peak is observed. Oxygen quenching of the emission is shown to be a sensitive method…
The dependence of some optical and physicochemical properties of evaporated GexAs40-xS60 films and their photoinduced changes on the average coordination number Z has been investigated. Arguments for a structural phase transition in thin films are given. In the Z dependences of the optical bandgap, refractive index an…
Steady-state quadrupole shape oscillations of air bubbles trapped in water were excited by amplitude modulation of the acoustic radiation pressure used for levitation. This method of exciting controlled shape oscillations may make possible noncontact dynamical measurements of the rheological properties of bubbles. Bub…
The resistivity of single-layered thin copper films with thickness of 17-124 nm, is studied as a function of the temperature and grain diameter. The resistivity of both as-deposited and 500 K annealed films is found to increase with decreasing film thickness. Analysis has shown that the grain-boundary scattering is th…