Materials Literature
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We consider the effective mass model of spinless electrons in single-wall carbon nanotubes that is equivalent to the Dirac equation for massless fermions. Within this framework we derive all possible energy independent hard wall boundary conditions that are applicable to metallic tubes. The boundary conditions are cla…
We introduce a simple two region model where the diffusion constant in a small region around each step on a vicinal surface can differ from that found on the terraces. Steady state results for this model provide a physically suggestive mapping onto kinetic coefficients in the conventional sharp-step model, with a nega…
The melting of ultrathin lubricant film by friction between atomically flat surfaces is studied. The additive noises of the elastic shear stress and strain, and the temperature are introduced for building a phase diagram with the domains of sliding, stick-slip, and dry friction. It is shown that increase of the strain…
We report that for the first time the nanoparticles of II-V semiconductor (ZnP2) were prepared and studied. ZnP2 nanoparticles were prepared by incorporation into zeolite Na-X matrix. Absorption, diffuse reflection (DR) and photoluminescence (PL) spectra of the ZnP2 nanoclusters incorporated into the supercages of zeo…
For large scale electronic structure calculation, the Krylov subspace method is introduced to calculate the one-body density matrix instead of the eigenstates of given Hamiltonian. This method provides an efficient way to extract the essential character of the Hamiltonian within a limited number of basis set. Its vali…
We present a theory of collective spin excitations in diluted-magnetic-semiconductor quantum wells in which local magnetic moments are coupled via a quasi-two-dimensional gas of electrons or holes. In the case of a ferromagnetic state with partly spin-polarized electrons, we find that the Goldstone collective mode has…
With a strong help of high-resolution photoemission spectroscopy we demonstrate in this paper that the large thermoelectric power observed in the layered cobalt oxides, such as ${\mathrm{Ca}}_{3}{\mathrm{Co}}_{4}{\mathrm{O}}_{9},$ ${\mathrm{Na}}_{0.6}{\mathrm{CoO}}_{2},$ and ${\mathrm{Bi}}_{2}{\mathrm{Sr}}_{2}{\mathrm…
The recent development of the superlattice nanowire pattern transfer (SNAP) technique allows for the fabrication of arrays of nanowires at a diameter, pitch, aspect ratio, and regularity beyond competing approaches. Here, we report the fabrication of conducting Si nanowire arrays with wire widths and pitches of 10-20…
Protein adsorption on polyelectrolyte multilayers (PEMUs) was evaluated using a combination of synthetic polyelectrolytes and proteins, including serum albumin, fibrinogen, and lysozyme. Variables such as surface and protein charge, polymer hydrophobicity, and hydrophilic repulsion were introduced to probe interaction…
Recent experimental measurements of large flexoelectric coefficients in ferroelectric ceramics suggest that strain gradients can affect the polarization and permittivity behaviour of inhomogeneously strained ferroelectrics. Here we present a phenomenological model of the effect of flexoelectricity on the dielectric co…
We report the first observation of band gap chemiluminescence of semiconductor quantum dots in solution and in nanoparticulate layers. The spectral position of the band gap chemiluminescence of CdSe/CdS core shell and InP nanocrystals depends on their particle size, allowing thus an efficient tuning of the emission co…
Two types of isotropic disordered nonergodic states exist in colloidal suspensions: glasses and gels. The difference between the two is that the nonergodicity, or elasticity, of gel stems from the existence of a percolated network, while that of glass stems from caging effects. Despite this clear difference in the ori…
A finite deformation continuum theory is derived from interatomic potentials for the analysis of the mechanics of carbon nanotubes. This nonlinear elastic theory is based on an extension of the Cauchy-Born rule called the exponential Cauchy-Born rule. The continuum object replacing the graphene sheet is a surface with…
Drug delivery systems (DDS) such as lipid- or polymer-based nanoparticles can be designed to improve the pharmacological and therapeutic properties of drugs administered parenterally. Many of the early problems that hindered the clinical applications of particulate DDS have been overcome, with several DDS formulations…
Abstract The formation of complexes between linear poly(acrylic acid) (PAA) and uranyl ions in aqueous solutions was studied with conductometry, potentiometry, thermal analysis, Fourier transform infrared, and luminescence spectroscopy methods. The stoichiometry of the PAA/UO complex on repeating units of a PAA basis…
Abstract The surfaces of the film samples of low‐density polyethylene (LDPE) were chemically modified with an aqueous solution of ammonium persulphate solution (0.1 M ) and Fe (NO 3 ) 3, 9H 2 O (0.2 M ) heated to about 80°C for 2.5 h for which polar groups like OH, 〉CO, COOH, etc., were generated on the surface of t…
The structural phase transitions of Sr 2 Ta 2 O 7 single crystals have been studied by the modulated temperature differential scanning calorimetry (MDSC), Brillouin scattering and dielectric spectroscopy. The specific heat ( C p ) was measured over a wide temperature range from −150°C to 25°C and from 100°C to 210°C.…
Abstract We report a novel porous fluorinated polyimide membrane with a cylinder structure fabricated by a wet phase inversion process, which is formed by a ternary system, polyimide/solvent/water. The porous polyimide membranes consisted of a thin top porous layer and three‐dimensionally ordered cylinder micropores.…
Abstract A series of blends with various compositions was prepared on the basis of polysulfone, polyethersulfone, and polyimide. These blends were characterized by different techniques, including Fourier transform IR spectroscopy, differential scanning calorimetry, dynamic mechanical analysis, and tensile stress–strai…
We present an inelastic x-ray scattering study of the quasi-one-dimensional blue bronze ${\mathrm{Rb}}_{0.3}{\mathrm{MoO}}_{3}.$ The charge-density-wave (CDW) dynamics is studied as a function of the temperature down to 40 K. At temperature higher than 100 K, the CDW-phase and -amplitude modes are identified, and foun…