Materials Literature
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Carbon nanotubes have been grown on Ni-coated Si substrates by microwave plasma-enhanced chemical vapor deposition with a mixture of methane and hydrogen gases at temperatures ranging from 520 to 700 °C. The density and the length of the carbon nanotubes increased with increasing growth temperature. At a growth temper…
Direct electronic structure measurements of a variety of colossal magnetoresistive (CMR) oxides show the presence of a pseudogap at the Fermi energy ${E}_{F}$ which drastically suppresses the electron spectral function at ${E}_{F}.$ The pseudogap is a strong function of the layer number of the samples (sample dimensio…
A self-assembly phenomenon in an extruded polystyrene/clay nanocomposite sample is observed during a temperature increase process. Wide-angle X-ray diffraction (WAXD), transmission electron microscopy (TEM), and infrared dichroism techniques have been employed to investigate the self-assembly phenomenon. The results s…
Equilibrium polymerization is studied here as a prototype for clustering transitions that commonly occur in systems of interacting particles at equilibrium. These transitions are often difficult to locate because of transition “rounding” associated with a limited extent of cluster growth, competing association or diss…
The frequency dependence of the electrical properties of the Bi12TiO20 single crystal was investigated by impedance spectroscopy. The data were presented in the Nyquist diagram form, from which electrical resistivity was determined. Values ranged from 1.93×105 and 1.07×103 Ω cm in the temperature range of 400–700 °C.…
Single‐phase α‐SiAlON with elongated grains is obtained from α‐Si 3 N 4 powder for a broad range of compositions of practical interest. Following the concept of nucleation and growth, two‐step firing is used for microstructure control. This method takes advantage of the slow transformation reaction from α‐Si 3 N 4 to…
The ${}^{59}\mathrm{C}\mathrm{o}\ensuremath{-}\mathrm{N}\mathrm{M}\mathrm{R}$ on single crystals of ${\mathrm{LaCoO}}_{3}$ has been studied in order to investigate the spin-state transition through the nuclear-spin relaxation in this compound. Below $T\ensuremath{\sim}35\mathrm{K},$ the spin-lattice and spin-spin rela…
We study Ising systems of spins with dipolar interactions. We find a simple approximate relation for the interaction energy between pairs of parallel lattice columns of spins running along the Ising spin direction. This relation provides insight into the relation between lattice geometry and the nature of the ordered…
Lactobacillus delbrueckii subsp. bulgaricus (L. bulgaricus) is a homofermentative bacterium that produces lactic acid during growth. We adapted the two-dimensional electrophoresis (2-DE) technique to study the response of this bacterium to acidity. De novo protein synthesis was monitored by [35S]methionine labeling of…
We argue that the ${(\mathrm{TMTSF})}_{2}{\mathrm{PF}}_{6}$ compound under pressure is likely a triplet superconductor with a vector order parameter $\mathbf{d}(\mathbf{k})\ensuremath{\equiv}{(d}_{a}(\mathbf{k})\ensuremath{\ne}0, {d}_{c}(\mathbf{k})=?, {d}_{{b}^{\ensuremath{'}}}(\mathbf{k})=0); |{d}_{a}(\mathbf{k})|&g…
In an attempt to study the specific influence of cross-linking on the α relaxation in polymer networks, a series of model heterocyclic polymer networks (HPN) with well-defined cross-link densities and constant concentration of dipolar units were studied. Model HPN systems were prepared by simultaneous trimerization of…
Self-organized semiconducting structures can be generated by including conjugated chains in block copolymers, it is reported here. Thin films of rod–coil copolymers containing a conjugated and a non-conjugated segment show nanoribbons of the conjugated material (see Figure), indicating that this approach may open the…
We synthesized Pb(Ni 1/3 Nb 2/3 )O 3 (PNN) and performed selected-area electron diffraction (SAD) in order to investigate the structure of the B-site array. In addition to the reflection from the basic cell, the SAD pattern of sintered PNN corresponds to the reciprocal plane normal to the [011] zone axis and showed di…
A novel method of transient eddy current analysis for moving conductors is proposed. In the analysis, different moving coordinate systems are used at each finite element in the conductor, respectively. The velocities of the coordinate systems are determined automatically at each time-step for the purpose of reducing t…
The only Landau-type model for antiferroelectric phase transitions was proposed by Kittel, in which two interpenetrating sublattices with opposite polarizations of equal amplitude were assumed. The theory, however, did not include any mechanism to specify the relative spatial positions of the two sublattices, and ther…
To estimate the stray loss distribution in power transmission systems like transformers, a new 3D eddy current analysis technique has been developed. This technique is based on the Integral Equation Method with Surface Impedance Model and is suitable for calculating eddy currents in a magnetized substance that has a c…
A new multidentate ligand L, 1,2-bis{[3-(2-pyridyl)pyrazol-1-yl]ethoxy}ethane, has been synthesized by linking two 3-(pyridin-2-yl)pyrazoles with a 1,2-bis(ethoxy)ethyl spacer. Coordination of L with zinc(II) and europium(III) centres has led to mononuclear complexes of [Zn(L)](ClO4)2 (1) and [Eu(L)Cl2](ClO4) (2). X-r…
Infrared and Raman spectra (4000-200 cm−1) were recorded for 4-vinylpyridine and vibrational assignments made for fundamental modes on the basis of frequency shifts of the coordinated ligand, of the group vibrational concept and comparison with the assignments for related molecules. the infrared spectra of M(4-vinylpy…
I propose a model of fracture in which the curvature of the crack tip is a relevant dynamical variable and crack advance is governed solely by plastic deformation of the material near the tip. This model is based on a rate-and-state theory of plasticity introduced in earlier papers by Falk, Lobkovsky, and myself. In t…
Abstract Biodegradable lactic acid based poly(ester‐urethanes) (PEU) were polymerized and their structure and rheological properties were characterized. The polymerization process comprised two steps: lactic acid monomer was oligomerized to low molecular weight prepolymer, and this was then linked to high molecular we…