Materials Literature
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This review paper illustrates the main normal and superconducting state properties of magnesium diboride, a material known since early 1950's, but recently discovered to be superconductive at a remarkably high critical temperature Tc=40K for a binary compound. What makes MgB2 so special? Its high Tc, simple crystal st…
Directly fused diporphyrins display the extensive pi conjugation as evinced by highly perturbed electronic absorption spectra as well as lowered and largely split first oxidation potentials. Such diporphyrins prepared include meso-beta doubly linked diporphyrins 7, meso-meso beta-beta beta-beta triply linked diporphyr…
This report presents the polarizability matrix of a tri-isotropic sphere. A tri-isotropic material exhibits coupling between electric, magnetic, and in addition, a third kind of material response. Each of these three fields creates three different kind of polarizations. The paper derives the polarizability components…
In past years, both experimental and analytical approaches have been developed for eliminating preferred orientation effects on powder X-ray diffraction patterns. The state of the art does not allow one to face the problem without difficult sample treatments, mechanical randomization, pole-figure study or pattern fitt…
Abstract We examine the crystallization and chain conformation behavior of semicrystalline poly(ethylene oxide) (PEO) and amorphous poly(vinyl acetate) (PVAc) mixtures with wide‐angle X‐ray diffraction (WAXD), small‐angle X‐ray scattering (SAXS), and small‐angle neutron scattering (SANS) experiments. For blends with P…
Abstract We used neutron reflectivity to measure the interfacial width in the immiscible system polystyrene/poly( n ‐butyl methacrylate) (PS/P n BMA). Measurements were made on the same samples at temperatures ranging from below the glass‐transition temperature ( T g ) of PS to slightly above. We observed significant…
The light emission of transient laser-produced cavitation bubbles in water is investigated in a range of ambient pressures up to 5 bar and laser energies up to 30 mJ. At elevated pressures bubble luminescence can be increased more than two fold for bubbles created with the same laser energy, and up to almost an order…
Abstract The preparation and characterization of two types of ionic poly( p ‐phenylene terephthalamide) (PPTA) is described. A sufficient number of ionic groups were added to render modified PPTA soluble in dimethylsulfoxide (DMSO). In one type, a hydrogen atom of the amide group was replaced by an ionic propanesulfon…
A novel approach for determining interfacial kinetics by excluding the mass transfer effect accurately by numerical simulation of fluid flow and mass transfer in a chemical reactor is presented. In the presence of surfactant, the biphasic hydroformylation of 1-dodecene catalyzed by water-soluble rhodium complex in a s…
Abstract Poly(δ‐valerolactone) (PVL) crystals in the form of chain‐folded lamellae were prepared by isothermal crystallization from a 2‐methylbutane‐2‐ol solution. Wide‐angle and small‐angle X‐ray diffraction data, obtained from PVL lamellae sedimented to form oriented mats, were supplemented with morphological and st…
We propose an approach to the (ferromagnetic) Kondo-lattice model in the low-density region, where the model is thought to give a reasonable framework for manganites with perovskite structure exhibiting the colossal magnetoresistance effect. Results for the temperature-dependent quasiparticle density of states are pre…
Abstract Side‐chain liquid‐crystalline‐ b ‐amorphous copolymers combine the thermotropic ordering of liquid crystals (LCs) with the physics of block copolymer phase segregation. In our earlier experiments, we observed that block copolymer order–order and order–disorder transitions could be induced by LC transitions. H…
Abstract Large enhancements of the melt strength of polypropylene (PP) were achieved by the introduction of high molecular weight polyethylene (PE) into PP. The viscoelastic properties of the high‐melt‐strength PP melts under shear flow were investigated. It was found that the rheological properties of the high‐melt‐s…
A series of Pd complexes of 3'-diphenylphosphino-2,2':5'2' '-terthiophene (1a, dppterth) in which the metal is coordinated in three different modes have been prepared and electropolymerized, resulting in the formation of conductive thin films. In [Pd2(mu-Cl2)(dppterth-P,C3)2] (3a) the metal is P,C-coordinated, in [PdC…
We report the first experimental observation of anisotropic magnetocaloric effect (MCE) in the Fe8 clusters. It is found that the magnetic anisotropy plays a very important role in the determination of the magnetocaloric effect. The maximum and minimum MCE's are observed when the applied magnetic fields are parallel a…
The simulations presented here are based on the program Mathematica as a tool to present electron density maps of two-dimensional crystal structures. The models give further insights into the relationship between the thermal displacement parameters and the quality of the electron density maps. Furthermore, users can r…
Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” opt…
A variety of phosphorus(V) octaethylporphyrin derivatives of the type [P(OEP)(X)(Y)](+)Z(-) (OEP: octaethylporphyrin) (X = CH(3), CH(2)CH(3), C(6)H(5), F; Y = CH(3), CH(2)CH(3), OH, OCH(3), OCH(2)CH(3), On-Pr, Oi-Pr, Osec-Bu, NHBu, NEt(2), Cl, F, O(-); Z = ClO(4), PF(6)) were prepared. X-ray crystallographic analysis…
New functionalized derivatives of 3,4-ethylenedioxypyrrole (EDOP, 5a) and 3,4-(1,3-propylenedioxy)pyrrole (ProDOP, 5b) as especially electron-rich monomers which yield highly electroactive and stable conducting polymers useful for a diverse set of applications have been synthesized. N-Alkylations of ProDOP were carrie…
We investigate how the dynamics of a single chain influences the kinetics of early stage phase separation in a symmetric binary polymer mixture. We consider quenches from the disordered phase into the region of spinodal instability. On a mean field level we approach this problem with two methods: a dynamical extension…