Materials Literature
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In the band theory of ferromagnetism there is a relative shift in the position of majority and minority spin bands due to the self-consistent field due to opposite spin electrons. In the simplest realization, the Stoner model, the majority and minority spin bands are rigidly shifted with respect to each other. Here we…
The ditopic ligand 3 has been synthesized. In its deprotonated form, it reacts with copper(II) ions to form a tetranuclear complex 1 of the [2 × 2] CuII4 grid type, the structure of which has been confirmed by X-ray crystallography. Magnetic studies of complex 1 indicate a very weak antiferromagnetic coupling between…
A compact electron cyclotron wave resonance (ECWR) source has been developed for the high rate deposition of hydrogenated tetrahedral amorphous carbon (ta-C:H). The ECWR provides growth rates of up to 900 Å/min over a 4″ diameter and an independent control of the deposition rate and ion energy. The ta-C:H was deposite…
A radiochromic film extrapolation method is described for the measurement of surface dose from high energy photon beams. Extrapolated central axis entrance surface dose using Gafchromic film for a field size is and of for 6 and 10 MV x rays, respectively. Extrapolated surface dose for a field with a 10 mm perspex bloc…
A survey is given on analytical techniques currently applied to the surface characterization of biomedical polymers. The techniques include spectroscopies, thermodynamic and electrochemical measurements and microscopies, respectively. To illustrate the motivation for surface analysis, the hypotheses on the correlation…
We have proposed a micromachined system with the aim of controlling injection of DNA into cells. The injection system is composed of two components: hollow microcapillaries for injection and microchambers for trapping cells. The hollow microcapillary array, the most important part of the system has been fabricated. In…
Recent progress related to the investigation of infrared and microwave properties of the AgNbO3 and AgTaO3 single crystals and Ag(Ta,Nb)O3 ceramics is reviewed and discussed with the aid of new crystallographic considerations and symmetry approach. It is shown that optical phonons at any temperature contribute to the…
Phosphorus (P) doped diamond thin films were grown by microwave plasma-assisted chemical vapor deposition (CVD) using phosphine (PH3) as a dopant source. The addition of PH3 in the gas ambient significantly influenced the optimal growth condition for diamond. The {111} surface of diamond was found to be the best surfa…
The structural modifications that a highly damaged region in diamond undergoes upon thermal annealing have been studied by molecular dynamic simulations. We verified our use of the Tersoff potential and our computational methods for describing the thermally driven transition of diamond to graphite by calculating the t…
Elastic stiffness constants in a perovskite-type oxide solid-solution system are discussed on the basis of the Landau-type free energy function expressed in terms of polarization and strain components. It is found that some of the elastic stiffness constants become extremely small in the vicinity of the morphotropic p…
We present a systematic theory of polymer reaction kinetics at an interface separating two immiscible melts, A and B, in each of which a fraction of chains carry reactive end groups. We consider arbitrary values of local group reactivity, Q b, and reactive group densities in either bulk, and, with the convention . At…
Strategies for obtaining low surface energy coating materials; include those for realizing surfaces rich in CF3 groups. Of these, ones that are low in cost and environmentally friendly (for example, avoid organic solvents) have a good chance of being introduced for everyday use. It is shown that waterborne nanodispers…
ADVERTISEMENT RETURN TO ISSUEPREVCommunicationNEXTA Novel Stepwise Degradation of Porphyrins. Synthesis and Structural Characterization of meso-Tetraphenylchlorophinato Nickel(II) and meso-Tetraphenylsecochlorinato Nickel(II)Christian Brückner, Ethan D. Sternberg, Jill K. MacAlpine, Steven J. Rettig, and David Dolphin…
That the Langmuir–Blodgett (LB) techniqueallows molecules to pack and orient in a well-defined fashion along a surface lends it suitability for preparing films of compounds with useful magnetic properties. Here is reported the synthesis of a semi-fluorinated iron complex (see Figure) that is extremely stable in the LB…
The structural rearrangement in samples of quenched isotactic poly(propylene) (iPP) submitted to different annealing treatments has been studied using simultaneous small- and wide-angle X-ray scattering (SAXS/WAXS) at the synchrotron radiation source of DESY, Hamburg. From a quantitative analysis of the WAXS profiles…
Two 3-hydroxybenzoate-inducible gentisate 1,2-dioxygenases were purified to homogeneity from Pseudomonas alcaligenes NCIB 9867 (P25X) and Pseudomonas putida NCIB 9869 (P35X), respectively. The estimated molecular mass of the purified P25X gentisate 1, 2-dioxygenase was 154 kDa, with a subunit mass of 39 kDa. Its struc…
Single crystals of Fe-40 at.% Al were cold rolled to a variety of strains up to 48%, when cracking occurred. The rolled crystals were heated at 10 K min−1 to 973 K in a differential scanning calorimeter, whereupon three exothermic peaks were observed. The cold rolling also induced a transition from paramagnetism to fe…
ADVERTISEMENT RETURN TO ISSUEPREVCommunicationNEXTIntermediate Range Order and Bonding Character in Disordered Network-Forming SystemsCarlo Massobrio, Alfredo Pasquarello, and Roberto CarView Author Information Institut de Physique et de Chimie des Matériaux de Strasbourg (IPCMS), 23 rue du Loess F-67037 Strasbourg, F…
Nature uses hydrogen bonds to regulate a variety of metal-based reactions. These effects are emulated in the stabilization of trigonal-bipyramidal, paramagnetic Co-OH complexes such as the mono- or dianionic redox-active complex 1 by use of a new hydrogen-bonding ligand.
We employ classical molecular dynamics simulations to study the rotational and translational dynamics of propylene carbonate. The homogeneous and heterogeneous contributions to the nonexponential relaxation are studied. The non-Gaussian parameter is found to be strongly correlated with the degree of heterogeneity. Fur…