Materials Literature
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Four monocyclic precursors were assembled in the total synthesis of the proposed structure 1-A of (+)-tolyporphin A O,O-diacetate (X=Ac). Comparison of the spectroscopic data demonstrated that synthetic tolyporphin O,O-diacetate did not match the O,O-diacetate prepared from natural (+)-tolyporphin A (X=H), calling for…
All articles of this category Despite their relatively uniform structural appearance, the synthesis of liquid crystalline materials for modern display applications involves a broad range of different synthetic methods, such as heterocyclic chemistry, ortho -metallation, transition metal catalyzed carbon-carbon couplin…
1H NMR spectroscopy was used to analyze the interactions between poly(amidoamine) (PAMAM) Starburst dendrimers (SBDs) 1–4 and several biologically important guests (pyridine, quinoline, quinazoline, nicotine and trimethadione). Association constants obtained from changes in the chemical shifts of the amide protons in…
Abstract We have investigated the magnetic properties of several TTF-based Mott insulators consisting of dimerized/trimerized-donor units, which are classified into three subgroups: (1) β′-(BEDT-TTF)2X (X = ICl2, AuCl2) and (BEDT-TTF)2GaCl4 as strong dimer systems, (2) α′-(BEDT-TTF)2IBr2 salt as a weak dimer system, a…
The crystalline structure and microstructure of some phases of the pseudo-binary system AlN–Al 2 O 3 are discussed, with special attention to the γ spinel phase. Samples with AlN content ranging between 43.3 and 3.5 mol % were studied after different thermal treatments. X-ray and neutron diffraction Rietveld peak-prof…
Optical absorption and luminescence spectra of the Sm<SUP>3+</SUP>-doped fluorophosphate glasses 75NaPO<SUB>3</SUB>- 24CaF<SUB>2</SUB>-1SmF<SUB>3</SUB> and 75NaPO<SUB>3</SUB>-24BaF<SUB>2</SUB>-1SmF<SUB>3</SUB>, the phosphate glass 75NaPO<SUB>3</SUB>-24.5ZnO-0.5Sm<SUB>2</SUB>O and the fluoride glass ZBLAN:Sm<SUP>3+</SU…
The solubility of bismuth oxide in barium titanate was investigated by X‐ray diffraction and scanning electron microscopy. Bismuth was added in two schemes: Ba 1‐ x Bi x TiO 3 , where only site balance was considered, and Ba 1‐1.5 y Bi y TiO 3 , where both site balance and charge balance were considered. The solubilit…
The relaxational dynamics of the ambient pressure phases of ethyl alcohol are studied by means of measurements of frequency dependent dielectric susceptibility. A comparison of the $\ensuremath{\alpha}$ relaxation in the supercooled liquid and in the rotator phase crystal indicates that the molecular rotational degree…
The various issues relating to the nature of high built-up stresses in diamond like carbon (DLC) films are presented and analyzed and the utility of pulse plasma technique in growing low residual stress DLC films is emphasized. Subsequently, sufficiently thick (2.2 μm) and hard (2000 kg/mm2) DLC films of significantly…
Calculation methods are an important tool for the determination of pressure effects due to high current area in electrical installations. In this contribution an improved standard calculation method and a new CFD-(computational fluid-dynamics) based method are introduced and compared with two other existing methods. T…
Controlling corrosion in production tubing is essential for maintaining production and for preventing loss of well control. Materials for use downhole have to meet criteria for corrosion resistance and also mechanical requirements. The potential corrosion rate can be estimated and the risks of sulphide stress corrosio…
In order to reveal the mechanism of partial discharge (PD) in electrical trees, an artificial single channel is studied as model for tree channels. In a long-narrow channel, the behaviour of PD is similar to that in an actual tree. When the length of the channel is decreased, the /spl phi/-q-n pattern of PD in the cha…
Abstract This paper reviews rinse‐added liquid fabric softener products including current and emerging technologies related to composition, raw materials, and manufacturing processes. An introductory overview of the historical drivers, market trends, advantages and disadvantages, and consumer habits and practices that…
New amphiphilic star polymers possessing a hyperbranched core and hydrophilic graft arms have been prepared. The synthetic strategy involved esterification of the 4,4-bis(4′-hydroxyphenyl)valeric acid based hyperbranched polymer with 3-(chloromethyl)benzoyl chloride to obtain the hyperbranched macroinitiator followed…
This paper is the first of a two-part study of the reaction products of laser-ablated lanthanide metal atoms with O 2 . There is general agreement with previous gas-phase and matrix-isolated neutral monoxides of the lanthanide elements. The present results agree with earlier identifications of CeO 2 and PrO 2 and make…
A large number of mild chemical reactions have recently been developed to modify porous silicon surfaces for optical or sensor applications. The modification reactions generally fall into two classes: those which link a reagent to the Si surface through Si-O linkages, and those which use Si-C linkages. Examples of the…
The microstructure and mechanical properties of silicon nitride, produced by a superplastic sinter‐forging technique, were investigated. The obtained silicon nitride exhibited a highly anisotropic microstructure, where rod‐shaped grains tended to be aligned perpendicular to the forging direction. A very high bending s…
A series of new yttrium(III) double-decker complexes with the same and different phthalocyaninato and porphyrinato ligands has been prepared. The homoleptic complexes Y ( P ) 2 ( P = Pc *(C 7 H 15 ) 8 , Pc *( OC 5 H 11 ) 8 ; Pc * = 2,3,9,10,16,17,23,24-octasubstituted phthalocyaninate) have been synthesized by treatin…
Starting from 1,3,5,7-tetramethylcyclotetrasiloxane as core, novel ferrocenyl silicon-containing dendrimers have been constructed up to the third generation, which contains 16 peripheral ferrocene moieties. As precursors of these ferrocenyl dendritic molecules, SiCl- and Siallyl-terminated cyclotetrasiloxane-based d…
Hemp fabric is hydrolyzed with cellulase, hemicellulase/cellulase, and cellulase plus additional β-glucosidase. The effect of the admixture of hemicellulase and β-glucosi dase is evaluated in terms of hydrolysis rate and product properties. The influence of mechanical action during the treatment is also taken into acc…