Materials Literature
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The dielectric and electrical properties of a BaTi4O9 film were investigated in order to evaluate its potential use in metal-insulator-metal (MIM) capacitors for rf/mixed signal integrated circuits. A high capacitance density of 4.62fF∕μm2 along with a low tanδ of 0.0025 were obtained at 100 kHz. A high capacitance de…
Abstract We consider the influence of a local, or effective, composition on dynamics in the miscible polymer blend PEO/PMMA. Quasielastic neutron scattering in combination with deuterium labeling is employed to determine characteristic relaxation times of the PEO component over spatial scales from 3 to 10 Å. Informati…
The adsorption of atoms and molecules of several gases of the Si(100)2x1 silicon reconstructed surface is investigated by surface differential reflectance spectroscopy. This UV-visible optical spectroscopy makes possible the discrimination between two adsorption modes, depending on whether or not the adsorption leads…
The magnetoresistance of high-quality epitaxial doped ZnO(:Ga) thin films with various electron concentrations ranging from 3.2×1018 to 1.3×1020cm−3 has been measured. All samples investigated exhibit a negative magnetoresistance at low magnetic fields. Its magnitude systematically depends on carrier concentration and…
Structural perfection up to the fifth generation of a polyphenylene dendrimer has been achieved by inserting p-terphenyl spacers into the arms of each branching unit (see picture). The stiff, monodisperse macromolecules with diameters up to 22 nm were synthesized in a stepwise manner, during which the topology of the…
Reciprocity between the power scattered by nested metamaterial shells and the power radiated by an antenna centered within those nested shells has been investigated. Resonant scattering caused by an incident, fundamental transverse-magnetic mode was found to be reciprocal to the power resonantly radiated by an electri…
Calcium metabolism in oysters is a very complicated and highly controlled physiological and biochemical process. However, the regulation of calcium metabolism in oyster is poorly understood. Our previous study showed that calmodulin (CaM) seemed to play a regulatory role in the process of oyster calcium metabolism. In…
When provoked, Notaden bennetti frogs secrete an exudate which rapidly forms a tacky elastic solid ("frog glue"). This protein-based material acts as a promiscuous pressure-sensitive adhesive that functions even in wet conditions. We conducted macroscopic tests in air to assess the tensile strength of moist glue (up t…
Surface doping of oxide nanoparticles is important in fields ranging from heterogeneous catalysis to optoelectronics. Here, we report the solvent-free synthesis of mixed calcium-magnesium oxide nanocrystals in the size range between 5 and 40 nm. Although CaMgO mixtures are thermodynamically forbidden on a macroscopic…
Single-walled carbon nanotubes (SWNTs) were successfully grown on SiO 2 /Si substrates at 450 °C by remote plasma enhanced chemical vapor deposition with a plasma power of 15 W. The ratio of D-band (disorder-induced mode) to G-band (tangential stretching mode) in the Raman spectra, an indicator of nanotube quality, is…
Characterization of a Zn0.7Mg0.3O∕ZnO heterostructure field-effect transistor (HFET) is reported. The HFET was based on a Zn0.7Mg0.3O∕ZnO∕Zn0.7Mg0.3O single quantum well (SQW) grown on an a-plane sapphire substrate by molecular-beam epitaxy, and was fabricated by a conventional photolithography technique combined with…
The electronic structure of monodispersed, hydrogen-passivated diamond clusters (diamondoids) in the gas phase has been studied with x-ray absorption spectroscopy. The data show that the bulk-related unoccupied states do not exhibit any quantum confinement. Additionally, density of states below the bulk absorption edg…
The adsorption of a biologically important glycoprotein, mucin, and mucin-chitosan complex layer formation on negatively charged surfaces, silica and mica, have been investigated employing ellipsometry, the interferometric surface apparatus, and atomic force microscopy techniques. Particular attention has been paid to…
Mixed protein-based hydrogels have been prepared by blending gelatin (G) with amorphous Bombyx mori silk fibroin (SF) and promoting beta-crystallization of SF via subsequent exposure to methanol or methanol/water solutions. The introduction of beta crystals in SF serves to stabilize the hydrogel network and extend the…
We present a study of the compression of polymer-grafted surfaces using the dissipative particle dynamics (DPD) method at constant chemical potential. We demonstrate the importance of performing simulations of compression at fixed chemical potential of the solvent by comparing the simulated force-compression curves at…
Abstract Our laboratory has reported the elaboration of an iterative strategy for the synthesis of dendritic macromolecules from conventional monomers. This synthetic method involves a combination of self‐regulated metal‐catalyzed living radical polymerization initiated from arenesulfonyl chlorides and an irreversible…
Spontaneous gradient copolymers were synthesized by atom transfer radical polymerization (ATRP) of acrylates and methacrylates and were subsequently employed to prepare macroinitiators for the synthesis of molecular brushes. Simultaneous copolymerizations of methyl methacrylate (MMA) and 2-(trimethylsilyloxy)ethyl acr…
We report circular-to-linear and linear-to-circular conversion of optical polarization by semiconductor quantum dots. The polarization conversion occurs under continuous wave excitation in absence of any magnetic field. The effect originates from quantum interference of linearly and circularly polarized photon states,…
Self-assembled silicon nanotubes with one-dimensional structure have been synthesized from silicon monoxide powder under supercritically hydrothermal conditions with a temperature of 470 degrees C and a pressure of 6.8 MPa. The silicon nanotubes were identified by transmission electron microscopy and high-resolution t…
The performance of hybrid exchange functionals is investigated within the framework of Density Functional Theory (DFT), in describing the properties of cubic and tetragonal ferroelectric phases of BaTiO3. A variable fraction ξ of non-local HF exchange is mixed with Becke's GGA formulation, and coupled with the LYP cor…