Materials Literature
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The pore sizes of hydrogen-methyl-siloxane-based porous spin-on-glass (SOG) thin films having different k values ( k =1.8–2.5) are comparatively studied using different nondestructive instrumental ways and also with reference to sorption porosimetry. The pore size and its spread are found to increase with increasing p…
Abstract Tetraaryl-substituted cerium(IV) double-decker porphyrin (2D), tetraaryl-substituted lanthanum(III) double-decker porphyrin (3D), and diaryl-substituted lanthanum(III) triple-decker porphyrins (4T•Me and 4T•MeO) were newly synthesized and their porphyrin ring rotation rates were systematically estimated by me…
The solvent behaviour of flash-cooled protein crystals was studied in the range 100--180 K by X-ray diffraction. If the solvent is within large channels it crystallizes at 155 K, as identified by a sharp change in the increase of unit-cell volume upon temperature increase. In contrast, if a similar amount of solvent i…
Thick films of poly(benzylsilsesquioxane) (BnSiO 3/2 ) particles, prepared by the sol–gel process, were deposited onto indium‐tin‐oxide‐coated glass substrates by electrophoresis for the application to the micropatterning of the films. BnSiO 3/2 particles were thermally softened and sintered at ∼50°C, which was above…
High sp3 fraction tetrahedral amorphous carbon (ta-C) films can be prepared using the filtered cathodic vacuum arc (FCVA). A by-product of the deposition process are small micrometer sized graphitic particles which are also incorporated into the film. The particle coverage of FCVA films is typically <5%, and th…
A detailed analysis is given of the conditions for the generation of misfit-induced defects (misfit wedge disclinations and disclination dipoles, periodical arrays of misfit wedge disclinations, and misfit-dislocation walls (MDWs)) in a two-phase cylindrical composite misfitting system. It is shown that the nucleation…
The spectroscopic properties of P2O5–Y2O3–Er2O3 and P2O5–Li2O–Al2O3–Y2O3–Er2O3 ultraphosphate glasses have been investigated. The concentration quenching rates of Er3+ in these two systems are lower compared with those in other oxide glasses. The spectral broadening of the measured fluorescence of 83.33P2O5–(16.67−x)E…
The factors influencing the cationization of microcrystalline cellulose with 3-chloro-2-hydroxypropyl triethylammonium chloride in the presence of NaOH were investigated. The course of the reaction was followed by estimating the nitrogen content of the cationized product while its structural features were confirmed by…
In this paper the synthesis and characterization of CdTe nanocrystals are presented. Opposite to what has been observed with Cd1–yMnyS, it has been impossible to include manganese ions in CdTe matrices. Only large rods of telluride were seen. ZnTe could also not be formed and again only Te rods were perceived. This cl…
The Rietveld method has proved to be a very effective means to characterize and quantify the crystalline phases and the amorphous phase in glass ceramic materials using X-ray powder diffraction data. The technique was applied to a borosilicate glass of the type used for high-level nuclear-waste containment, in order t…
Microbial biomineralization in a weathered volcanic ash deposit from the 1914 to 1915 A.D. eruption of Sakurajima volcano was investigated by transmission electron microscopy (TEM) and energy dispersive X-ray analysis (EDX). The solution chemistry of pore water was also analyzed to elucidate saturation conditions. In…
Tributyltin derivatives of 2-bromo-3-octylthiophene and 5-bromo-4-octyl-2,2′-bi(thiophene) have been selectively prepared. Condensation reactions in the presence of Pd2(dba)3(CHCl3)/4 PPh3 led to high yields (ca. 90%) of regioregular poly(3-octylthiophene) (Mw = 21.4 × 104, Mw/Mn = 1.48) and poly[4-octylbi(thiophene)]…
PII is a signal transduction protein that is part of the cellular machinery used by many bacteria to regulate the activity of glutamine synthetase and the transcription of its gene. The structure of PII was solved using a hexagonal crystal form (form I). The more physiologically relevant form of PII is a complex with…
Fourier transform infrared microspectroscopy (FTIRM) was used to investigate the organic and mineral phases of a calcified tissue (dentin) as a function of its location from predentin toward enamel. Thin dentin slices (decalcified or not) were fixed in formaldehyde and embedded in glycolmethylmethacrylate (GMA). Fixat…
The diamagnetic CeIV complex 1 is the main product of the reaction of the CeIII compounds [Ce{N(SiMe3)2}3] or CeCl3 with two equivalents of the polyhedral silsesquioxane (c-C6H11)8Si8O11(OH)2 in the presence of pyridine (py). Compound 1 is a potential homogeneous analogue of silica-supported rare earth metal catalysts…
The mode of action of essential oils from two buchu species (Agathosma betulina and A. crenulata, Rutaceae) from the Cape region of South Africa has been studied on smooth muscle in-vitro using guinea-pig ileum. At high concentration, the oils had an initial spasmogenic activity followed by spasmolysis. The spasmolyti…
Single crystals of 4.1% Cr3+ doped Cs2NaScCl6 were studied by variable temperature optical absorption and luminescence spectroscopy. The A2g4↔4T2g transition exhibits a great deal of fine structure both in absorption and emission spectra. The dynamic T⊗e Jahn-Teller effect in the Cr3+ T2g4 excited state is analyzed on…
The diffuse scattering in the diffraction pattern of the icosahedral Al-Pd-Mn quasicrystalline phase has been measured on an absolute scale by X-ray and neutron scattering on single-grain samples. Most of the diffuse scattering can be interpreted in the framework of the elasticity theory of icosahedral quasicrystals c…
The shear-induced self-diffusion and rheology of concentrated suspensions of noncolloidal hard spheres have been studied experimentally. The combined results provide an interesting physical picture. The projection of the trajectories of individual particles on the vorticity (z)–velocity (x) plane were determined throu…
A novel approach to model diffraction line shifts caused by elastic residual or applied stresses in textured polycrystals is proposed. The model yields the complete strain and stress tensors as a function of crystallite orientation, as well as the average values of the macroscopic strain and stress tensors. It is part…