Materials Literature
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We present a critical theoretical study of electronic properties of silicon nanoclusters, in particular the roles played by symmetry, relaxation, and hydrogen passivation on the the stability, the gap states and the energy gap of the system using the order-N [O(N)] non-orthogonal tight-binding molecular dynamics and t…
In this work, we address issues pertinent to the understanding of the structural and electronic properties of Si_{1-x} Ge_{x}alloys, namely, (i) how does the lattice constant mismatch between bulk Si and bulk Ge manifests itself in the alloy system? and (ii) what are the relevant strain release mechanisms? To provide…
The effective exchange interactions of magnetic overlayers Fe/Cu(001) and Co/Cu(001) covered by a Cu-cap layer of varying thickness were calculated in real space from first principles. The effective two-dimensional Heisenberg Hamiltonian was constructed and used to estimate magnon dispersion laws, spin-wave stiffness…
The mechanisms and kinetics of the reduction of powdered Fe 2 O 3 and Fe 3 O 4 samples have been investigated under nonisothermal conditions to provide a detailed insight into the processes occurring. Both conventional linear heating temperature-programmed reduction (TPR) and constant rate temperature-programmed reduc…
A novel and simple preparation method for single monodisperse CdS nanoparticles with controllable size and stability against oxidation is presented. Double-hydrophilic block copolymers consisting of a solvating poly(ethylene glycol) PEG block and a poly(ethylene imine) PEI binding block have been used as effective sta…
Integral isoconversional methods may give rise to noticeable systematic error in the activation energy when the latter strongly varies with the extent of conversion. This error is eliminated by using an integration technique that properly accounts for the variation in the activation energy. The technique is implemente…
Amorphous carbon nitride films have been grown by ion beam assisted deposition (IBAD) under different process conditions. The films were found to be graphitic, with π bonds between C and N atoms and a [N]/[C] ratio below 0.3. There is a relationship between the contribution of electrons from C and N atoms to the π bon…
Since 2,3-bis( n -decyloxy)anthracene (DDOA) is a good gelling agent for a large number of solvents including propylene carbonate (PC), the electrochemical properties of organogel electrolytes based on DDOA have been investigated. The presence of tetraalkylammonium salts in DDOA/PC gels is shown to preserve the three-…
Lysine 2,3-aminomutase (LAM) catalyzes the interconversion of L-lysine and L-beta-lysine. The enzyme contains pyridoxal 5'-phosphate (PLP) and a [4Fe-4S] center and requires S-adenosylmethionine (SAM) for activity. The hydrogen transfer is mediated by the 5'-deoxyadenosyl radical generated in a reaction of the iron-su…
We solve the linearized Boltzmann equation for currents perpendicular to the planes of the layers for two semi-infinite metallic layers in the presence of diffuse and specular scattering at the interface. In particular, the variation of chemical potential within a mean-free path of the interface is investigated. The d…
A systemic study on the synthesis, characterization, degradation, drug release, and stability of nonlinear fatty acid terminated poly(sebacic anhydride) (PSA) is reported. Ricinoleic acid was transformed into a nonlinear fatty acid by esterification with fatty acid chlorides of C8-C18 chain length in the presence of p…
The effect of Fe doping $(<~10%)$ on polycrystalline samples of ${\mathrm{La}}_{0.7}{\mathrm{Sr}}_{0.3}{\mathrm{MnO}}_{3}$ has been studied by means of x-ray diffraction, resistivity, ac susceptibility, magnetization, and magnetoresistance measurements. Fe doping does not affect the lattice structure, but it weaken…
Orientational relaxation of supercooled o -terphenyl (OTP) is studied over a wide range of temperatures and time scales using optical heterodyne detected optical Kerr effect techniques. A combination of experimental setups made it possible to study the dynamics for greater than six decades of time (100 fs to hundreds…
The adsorption behavior of carboxymethyl cellulose onto amino-terminated surfaces was investigated by means of ellipsometry. The adsorbed amount decreases with ionic strength decrease, in agreement with the screening-reduced adsorption regime. The pH has a strong influence on the adsorption behavior. At pH values lowe…
A molecule-based magnet of formula (SP)MnCr(ox) 3 ·H 2 O has been synthesized, where SP + stands for a new N -methylated pyridospiropyran cation and ox 2- represents the oxalate anion. The compound orders ferromagnetically at 5.5 K and exhibits crystalline-state photochromism. The main spectrokinetic data of the UV-in…
In an effort to understand the low-temperature behavior of recently synthesized molecular magnets, we present numerical evidence for the existence of a rotational band in systems of quantum spins interacting with nearest-neighbor antiferromagnetic Heisenberg exchange. While this result has previously been noted for ri…
Formation, stability patterns, and decay channels of silver dianionic and gold trianionic clusters are investigated with Penning-trap experiments and a shell-correction method including shape deformations. The theoretical predictions pertaining to the appearance sizes and electronic shell effects are in remarkable agr…
The novel bridging ligand 1,8-bis(2,2':6',2"-terpyridyl)anthracene (btpyan) is synthesized by three reactions from 1,8-diformylanthracene to connect two [Ru(L)(OH)]+ units (L = 3,6-di-tert-butyl-1,2-benzoquinone (3,6-tBu2qui) and 2,2'-bipyridine (bpy)). An addition of tBuOK (2.0 equiv) to a methanolic solution of [RuI…
Recent structural studies of ferroelectric ${\mathrm{PbZr}}_{1\ensuremath{-}x}{\mathrm{Ti}}_{x}{\mathrm{O}}_{3}$ (PZT) with $x=0.48,$ have revealed a monoclinic phase in the vicinity of the morphotropic phase boundary (MPB), previously regarded as the boundary separating the rhombohedral and tetragonal regions of the…
The crystal structure of ${\mathrm{NaNO}}_{2}$ has been refined in the ferroelectric phase at 338, 378, and 418 K. The evolution of the thermal motion with increasing temperature has been studied by comparing the anisotropic displacement parameters, including earlier values at low temperatures. The results support the…