Materials Literature
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Since ebselen is known to have glutathione peroxidase-like activity and inhibitory effects on lipoxygenase and cyclo-oxygenase, we investigated its protective effects against cerebral ischemia in the rat using microdialysis. Ebselen was given through a gastric tube 30 min before occlusion in the experimental groups. I…
Nonplanarity and conformational flexibility of alkyl- and phenyl-substituted rosarin (see diagram) determine its photophysical properties. Both neutral and protonated forms are nonfluorescent. Upon excitation, rapid deactivation occurs by internal conversion to the ground state. Six molecular orbitals have to be taken…
We correct a statement made in a recent paper (Angell S et al 1998 J. Phys.: Condens. Matter 10 L73-8) that computer simulations on supercooled liquid silicon were not available. We further point out that the simulations that have been made provide an important confirmation of the findings of Angell et al , from the x…
Abstract Nylon 6 was grafted with a zinc‐neutralized ethylene/acrylic acid copolymer (CP) to produce four different modified polyamides (MPA) with varying CP content. These were mixed with four polyethylenes with different viscosities and the blends were blow‐molded into bottles. The clearest MPA lamina was developed…
Abstract A specimen of zirconolite, collected from the type locality of the mineral originally described as zirkelite at Jacupiranga, São Paulo, Brazil has been re-examined and its mineral chemistry more completely characterized. All crystals studied are metamict and display very fine lamellar oscillatory zoning (1–3…
Abstract The chitosan derivatives containing antiradical fragments in the polymer side chain have been synthesized by interaction of the partially quaternized chitosan(QCH) with gallic acid (GA). The antioxidative activity of the chitosan derivatives — QCH‐GA was investigated by thiobarbituric method. Introduction of…
The initial stages of nucleation during liquid–liquid phase separation in mixtures of high molecular weight polymers was studied by time-resolved small angle neutron scattering. Phase separation was induced either by decreasing temperature or by increasing pressure. One of the blend components was labeled with deuteri…
The experimentally interesting ${\mathrm{Nb}}_{3}$ and ${\mathrm{Nb}}_{4}$ clusters and their cations have been studied in great detail using density-functional methodology in conjunction with relativistic effective core potentials. Close attention has been paid to full optimization along the flat potential energy sur…
Four substituted dithiobiurets (i.e., 1,5-diphenyl-2,4-dithiobiuret [DPDTB]; 1-anisidyl-5-phenyl 2,4-dithiobiuret [APDTB]; 1-tolyl-5-phenyl 2,4-dithiobiuret [TPDTB]; and 1-cholorophenyl-5-phenyl 2,4-dithiobiuret [CPDTB]) were synthesized to study their inhibiting effect on mild steel (MS) corrosion in 5 N hot hydrochl…
Within a semiclassical model, we investigate the dynamic neutralization and relaxation of slow ${(E}_{\mathrm{kin}}<100\phantom{\rule{0ex}{0ex}}\mathrm{eV})$ multiply charged ions which are reflected on metal surfaces. Special emphasis is devoted to near-surface interaction mechanisms. Our model includes a Monte Ca…
Joining is an enabling technology for the application of structural ceramics at high temperatures. Metal foil diffusion bonding is a simple process for joining silicon carbide or boron carbide by solid-state, diffusive conversion of the metal foil into carbide and silicide compounds that produce bonding. Metal diffusi…
Ethylene-propylene-diene rubber (EPDM) was reacted with thioacetic acid in the presence of 2,2′-azoisobutyronitrile (AIBN), giving rise to thioacetate-modified EPDM (EPDMTA). The extent of the incorporation was studied as a function of both thioacetic acid and AIBN concentration and reaction time. The products were an…
The variation of electrical resistance of near stoichiometric NiTi during some thermo-mechanic procedures was studied in this paper. The results show that when the R-phase does not exist in the near stoichiometric NiTi wire, the electrical resistance of NiTi wire increases linearly with the increase of strain at const…
The in situ thermal poling processes in germanosilicate fibers for positive and negative poling voltages are significantly different. Thermal poling of silica fibers consists of two processes: the faster linear process of charge migration and the subsequent single exponential process of charge ionization. Both the shi…
The performance and characteristics of a no rinse, titanium based conversion coating on an aluminium alloy have been studied using electrochemical techniques and transmission electron microscopy. Coatings were prepared from an aqueous H 2 TiF 6 solution, spin coated onto aluminium alloy 3003. The electrochemical behav…
The variation of the optical characteristics of thin films of oxidized porous silicon as a function of the preparation regime and subsequent heat treatment is investigated by ellipsometry. It is shown that the refractive index, optical thickness, and extinction coefficient of porous silicon films decrease monotonicall…
Abstract Bei der Hydroaminierung von Alkenen und Alkinen handelt es sich um Reaktionen, die auch 1999 noch nicht zum Standardwerkzeug der Organischen Chemie gehören. Viele der hier beschriebenen Verfahren sind auf einzelne Substratklassen oder sogar einzelne Substrate beschränkt, verwenden hochempfindliche und teure K…
Metastable amorphous ZrO 2 ‐Al 2 O 3 powders were hot‐pressed at low temperatures (873 and 923 K), under moderately high pressures (500 and 750 MPa), and amorphous pellets with 1%‐8% porosity were obtained. Crystallization of the amorphous pieces in the temperature range of 1173–1673 K produced a range of ultrafine mi…
Long bulky substituents do not affect the nonlinear optical properties of the octopolar system 1,3,5-trihydroxy-2,4,6-trinitrobenzene (THTNB), but lend it liquid crystal (LC) properties, as demonstrated here. The synthesis of this LC derivative (see Figure for structure) is described as are its thermal, mesomorphic, a…
Time-resolved fluorescence, particularly of millisecond lanthanide emission, is of considerable interest because of potentially increased sensitivity when short-lived autofluorescence is a problem. Lanthanides have also previously been shown to be excellent donors in resonance energy transfer measurements, where a lan…