Materials Literature
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Particles of micrometer to nanometer size often aggregate to form branched structures. Such materials include metals and metal oxides as well as biological and polymeric materials (considering the persistence length as a primary unit). Characterization of such structures is difficult since they typically display disor…
Solutions in the form of series expansion, as the Born approximation, are very useful for describing time-independent scattering of quantum particles. In this work, it is mathematically demonstred that such solutions, when applied to multiple beam scattering phenomena, can lead to energy violation where the number of…
It has been shown within density-functional theory that in Mn$_{12}$-acetate there are effects due to disorder by solvent molecules and a coupling between vibrational and electronic degrees of freedom. We calculate the in-plane principal axes of the second-order anisotropy caused by the second effect and compare them…
We have studied the problem of phase stability in Fe-Pt and Co-Pt alloy systems. We have used the orbital peeling technique in the conjunction of augmented space recursion based on the tight binding linear orbital method as the method for the calculation of pair interaction energies. In particular, we have generalized…
We demonstrate a variety of ordered patterns, including hexagonal structures and chains, formed by colloidal particles (droplets) at the free surface of a nematic liquid crystal (LC). The surface placement introduces a new type of particle interaction as compared to particles entirely in the LC bulk. Namely, director…
We investigate in this paper the imaging properties of an absorptive left-handed material (LHM) slab. For a line source, a geometric explanation to the reason of the thickness limitation on an ideal slab is given. For a lossy slab, the imaging properties are determined by the wavelength, the slab thickness, the distan…
We propose using an equation-of-motion approach as an impurity solver for dynamical mean field theory. As an illustration of this technique, we consider a finite-$U$ Hubbard model defined on the Bethe lattice with infinite connectivity at arbitrary filling. Depending on the filling, the spectra that is obtained exhibi…
Temperature (4.2-260 K) and magnetic field (0-50 kOe) dependencies of the dc electrical resistance, dc magnetization, and ac magnetic susceptibility of (Sm0.65Sr0.35)MnO3 prepared from high purity components have been studied.
Magnetic properties of MnAs were studied as a function of temperature with a superconducting interference device (5 K to 350 K), and atomic force microscopy/magnetic force microscopy (20 K to 360 K). Structural and magnetic properties of MnAs depend on film thickness both near and far below the Curie temperature. In s…
Raman scattering in relaxor ferroelectric PbMg1/3Ta2/3O3 (PMT) was investigated in the single crystalline form in the temperature range of 20 - 295 K. Anomalous temperature dependence of the integrated intensity and the Raman line contours were found at the diffuse phase transition. A correlation between the anomalies…
A unified treatment for the propagation of classical waves in inhhomogeneous media is proposed. We deal with four kinds of waves, they are the acoustic wave in fluid, the elastic shear wave in two diemnsional solid, and the E- and H-polarized electromagnetic waves in two diemnsional lossless medium. We first show that…
The need for viable materials for optical communications, display technologies, and biomedical engineering is driving the creation of multilayer composites that combine brittle materials, such as glass, with moldable polymers. However, crack formation is a critical problem in composites where thin brittle films lie in…
A series of high-activity manganese−cerium oxide catalysts for the low-temperature (373−453 K) selective catalytic reduction (SCR) of NO x with ammonia were prepared. They were prepared by using the citric acid method (CA), coprecipitation method (CP), and impregnation method (IM) and were characterized by XRD, ESR, X…
Die Bindung von Dimethylviologen in einem Zn-Porphyrin-Wirt steigert die Affinität des Wirts für N-Donorliganden und umgekehrt (siehe Schema). Diese positiven heterotropen allosterischen Effekte werden genutzt, um komplexe Gleichgewichtsmischungen in Richtung auf eine einzelne, selbstorganisierte Spezies zu lenken. Au…
Wie stark ist die H⋅⋅⋅H-Brücke in festem BH3NH3? Periodische Dichtefunktionalrechnungen sagen einen mittlere Energie von 12.7 kJ mol−1 voraus. Diesem Ergebnis zufolge wäre die Wechselwirkung unter den schwächeren Diwasserstoff-Brücken einzustufen.
Abstract N,N ′‐disubstituted hyperbranched polyureas with methyl, benzyl, and allyl substitutents were synthesized starting from AB 2 monomers based on 3,5‐diamino benzoic acid. Carbonyl azide approach, which generates isocyanate group in situ on thermal decomposition, was used for the protection of isocyanate functio…
Wie Lackmuspapier bei steigendem pH-Wert seine Farbe von Rot nach Blau ändert, so verschiebt sich die Fluoreszenzemission des Oxazol-Derivats 1 von Grün nach Blau. Durch Bestimmung des Intensitätsverhältnisses der Fluoreszenzemissionen der zwei Spezies – nach Ein- oder Zweiphotonenanregung – kann 1 als pH-Sensor bei m…
The development of renin inhibitors for the treatment of hypertension requires highly sensitive substrates to evaluate potency and to characterize the mechanism of tight-binding inhibitors. A series of intramolecularly quenched fluorogenic renin substrates, based on the N-terminal tetradecapeptide sequence of human an…
KSI (ketosteroid isomerase) catalyses an allylic isomerization reaction at a diffusion-controlled rate. A hydrogen bond network, Asp(99).Water(504).Tyr(14).Tyr(55).Tyr(30), connects two critical catalytic residues, Tyr(14) and Asp(99), with Tyr(30), Tyr(55) and a water molecule in the highly apolar active site of the…
We present a clear signature of the Schottky effect in a rf photoinjector using photons with energy lower than the Mg cathode work function. This signature is manifested by the shift in the rf phase angle for the onset of the detection of photoelectrons via single-photon absorption and allows for a reasonable estimate…