Materials Literature
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In this article we describe research into the molecular design features for potential thermotropic biaxial nematogens of low-molar mass. We discuss how we can systematically change the shape of molecular structures in view of this aim of our work. The optical biaxialities of the materials prepared were tested through…
Other| December 01, 1998 Cation dynamics and premelting in lithium metasilicate (Li 2 SiO 3 ) and sodium metasilicate (Na 2 SiO 3 ); a high-temperature NMR study Ann M. George; Ann M. George Stanford California, Department of Geological and Environmental Sciences, Stanford, CA, United States Search for other works by…
Abstract We report the electronic structures of three large band gap borates β‐BaB 2 O 4 , YBO 3 and LuBO 3 , and corresponding binary oxides BaO, Y 2 O 3 , Lu 2 O 3 and B 2 O 3 . The main objective of this investigation is to explore how the electronic structures of complex oxides relates to their binary oxides, and…
The solution and adsorption behavior of a series of diblock copolymers of hydrophobic poly(dimethyl siloxane) and hydrophilic poly(2-ethyl-2-oxazoline) was studied. These block copolymers formed large polydisperse micelles in an aqueous solution. The critical micelle concentration was lower than 2 mg L -1 . The adsorp…
Abstract Lode, a dioctahedral illite-rich clay from Latvia belonging to the mica group of clay minerals, undergoes thermal transformation via a series of structurally disordered intermediate phases. Despite containing high levels of paramagnetic Fe substituted into the octahedral sites, 29 Si and 27 Al magic angle spi…
The optical dielectric function of zinc is measured by excitation of surface plasmon-polaritons on a silica prism coated in MgF2 and zinc in the Kretchmann configuration and on a zinc-covered silica grating for a range of wavelengths in the visible spectrum. By exciting the surface plasmon at the zinc-MgF2 or zinc-gra…
Cellulose carbamate and ester derivatives were synthesized in homogeneous solutions of lithium chloride (LiCl)/N,N-dimemyl-acetamide (DMAc) by the reaction of cellulose with ethyl 4-isocyanatobenzoate and the activated esters of N,N-dimethyl-aminobenzoic acids. Comparative reactions were performed with phenyl isocyana…
The inhibiting effect of Schiff base N,N´-o-phenylen-bis (3-methoxysalicylaldenimine), designated as V-ph-V, on corrosion of copper in 1.0 M hydrochloric acid (HCl) or 1.0 M sodium chloride (NaCl) solutions under various conditions was studied using the potentiostatic polarization method and the alternating current (A…
BaTiO 3 particles of ultrafine size and high crystallinity were produced by a spray−coprecipitation technique. To improve stability, titanium isopropoxide was acylated using acetic acid. The sol solutions were prepared by mixing the titanium acylate with aqueous barium acetate . Spray−precipitation was performed in co…
The high-order harmonics of temperature wave were detected in a thin film by inputting a square pulse train with a variable duty factor to generate temperature modulation. In Fourier analysis, the harmonics were observed up to the 42 th order and the mathematical rule was experimentally confirmed. This principle was a…
In this article, electron beam induced changes in the refractive index and film thickness of time relaxed amorphous AsxS100−x (with x=30–45) and AsxSe100−x (with x=40–70) are studied. The largest index change (∼0.08) in AsxS100−x films is found when x=40. The corresponding value (∼0.06) for AsxSe100−x films is met whe…
Six styrene derivatives meta-substituted with acetal-protected glucofuranoses ( 1 ) and ( 2 ), galactopyranose ( 3 ), fructopyranose ( 4 ), and sorbofuranose ( 5 ) and para-substituted with acetal-protected glucofuranose ( 6 ) were synthesized by the Williamson reactions of m - or p -(chloromethyl)styrene with the cor…
The structural characterization of syndiotactic copolymers of propene with 1-butene, prepared with a single-center metallocene-based catalyst, is reported. The copolymers are crystalline in a whole range of comonomer composition. The increase of a and b axes of the unit cell from the values of syndiotactic polypropyle…
All articles of this category The development of porphyrins functionalized by the CH 2 PPh 3 Cl moiety has enabled a range of new porphyrins to be conveniently prepared. This is best demonstrated by their utility in the preparation of building blocks for large porphyrin arrays. Examples, of the utility of these phosph…
Previous studies and the crystal structure of Anabaena PCC 7119 FNR suggest that the side chains of Arg100 and Arg264 may be directly involved in the proper NADP+/NADPH orientation for an efficient electron-transfer reaction. Protein engineering on Arg100 and Arg264 from Anabaena PCC 7119 FNR has been carried out to i…
: Electron beam X-ray microanalysis with semiconductor energy-dispersive spectrometry (EDS) performed with standards and calculated matrix corrections can yield quantitative results with a distribution such that 95% of analyses fall within +/-5% relative for major and minor constituents. Standardless methods substitut…
We study the possibility of using hydrogen-bonding interactions to promote the stabilisation of phase biaxiality in nematic binary mixtures of oblate and prolate thermotropic mesogens. We extend Onsager's theory of the isotropic-nematic transition to allow for such selective associations among unlike species and we us…
Abstract The crystal structure of chloromenite, Cu 9 O 2 (SeO 3 ) 4 Cl 6 , a = 14.170(3) Å, b = 6.262(1) Å, c = 12.999(3) Å, β = 113.05(1)°, V = 1061.3(4) Å 3 , Z = 2, space group I 2/ m , has been solved by direct methods and refined to an R ( F ) index of 0.051 ( wR ( F 2 ) = 0.128). The structure is based on unbran…
Terminal-functionalized polyesters were synthesized by enzymatic ring-opening polymerization of lactones in the presence of a functional alcohol. The alcohol initiated the ring-opening polymerization of lactones using Candida antarctica lipase as catalyst to introduce the alcohol moiety at the polymer terminal (“initi…
Other| December 01, 1998 Study of the Al coordination in mullites with varying Al:Si ratio by 27 Al NMR spectroscopy and X-ray diffraction P. Rehak; P. Rehak Friedrich-Schiller-Universitaet Jena, Jena, Federal Republic of Germany Search for other works by this author on: GSW Google Scholar G. Kunath-Fandrei; G. Kunath…