Materials Literature
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Abstract An experimental approach based on the freezing‐point depression of a solvent in a swollen gel has been developed to characterize the structure of rubber networks. This property depends on the conditions required for the formation of crystalline nuclei, which are limited by the elastomer network restrictions.…
The radio-frequency characteristics of p-type diamond field-effect transistors with hydrogen surface termination were numerically analyzed using an equivalent-circuit model. From the gate-source capacitance (CGS)-voltage (VGS) results extracted from measured s parameters, the authors found a plateau in CGS within a ce…
The kinetics of relaxation and recombination processes of excitons in an epitaxial-grown thick ZnO layer has been examined using time-resolved cathodoluminescence. The unique feature of this technique allows the full analysis of excitation from thermal equilibrium into true steady state and the relaxation back into th…
X-ray analysis of some 1,3-dipyrrolyl-1,3-propanediones synthesized from pyrroles and malonyl chloride derivatives revealed 1D supramolecular networks formed by N-H...O=C interactions in the solid state. Micro- and nanometer-scale morphologies of porous, fibrous, and sheet structures were fabricated by hydrogen-bondin…
The optical properties of PbSe nanocrystal quantum dots (NQDs) were studied as a function of applied hydrostatic pressure over the range from ambient to 5.4GPa. PbSe NQDs exhibit an energy gap that is dominated by quantum confinement. Despite such strong confinement, the authors find that the energy gaps of 3, 5, and…
Abstract Poly(ethylene terephthalate) (PET) fibers were treated with 60 Co‐γ‐ray and grafted with acrylic acid. The resulting fibers were further grafted with chitosan (CS) via esterification. Afterward, hyaluronic acid (HA) was immobilized onto CS‐grafting fibers. The antibacterial activity of CS against S. aureus ,…
This article presents a gripper actuated by a pair of differential shape memory alloy (SMA) springs. The mechanical structure of the gripper includes a pair of fingers, a coupler, a tension rod, a slider, and a frame. An experimental setup of the SMA gripper is established. The SMA actuator is heated by the electric c…
A ballistic strip of graphene (width $W⪢\text{length}$ $L$) connecting two normal metal contacts is known to have a minimum conductivity of $4{e}^{2}∕\ensuremath{\pi}h$ at the Dirac point of charge neutrality. We calculate what happens if one of the two contacts becomes superconducting. While the ballistic conductance…
A combined approach of molecular modeling and experiment has been applied to optimize the electrical conductivity of LaCrO3 by screening all group IIa elements that may partially substitute La. Electronic structures of both doped and undoped LaCrO3 have been calculated and a semiconducting state for M2+-doped LaCrO3 h…
The crystal structure and multiferroic properties of single-phase (Bi0.9La0.1)FeO3–Ba(Fe0.5Nb0.5)O3 ceramics were investigated. The rhombohedral-type structure of 1.0(Bi0.9La0.1)FeO3) was transformed to a monoclinic-type structure for the 0.5(Bi0.9La0.1)FeO3–0.5Ba(Fe0.5Nb0.5)O3) composition. It shows the coexistence o…
In this letter the author calculate, by applying fracture mechanics, Young’s modulus reduction for a nanotube, imposed by the presence of nanodefects, with specified size, shape, and number. The results are compared with atomistic and continuum simulations. Vacancy fraction, eccentricity, orientation, and interaction…
The Cpx signalling system of Escherichia coli and Salmonella enterica senses extracytoplasmic stress and controls expression of factors that allow the bacterium to adapt to these stressors and thereby enhance survival. Many of the Cpx-responsive genes products are of unknown function. We determined the crystal structu…
In this work the authors investigated the electrical conducting properties of multiwalled carbon nanotube (MWNT) networks in the flexible polydimethylsiloxane rubber as a function of applied voltages. The results indicated that the I-V curves showed nonlinear relationships, which can be fitted to quadratic functions.…
Abstract Three series of the processed linear low density polyethylene samples containing: 0–15 wt % corn starch, 0.5 wt % of a photoinitiator (PI), and 5 wt % corn starch + 0.5 wt % of a PI were prepared using an internal mixer at 170°C for 5 min in a closed system. The melt flow index (MFI) and apparent viscosity (μ…
The imprint of a ferroelectric thin film capacitor is studied using an improved model consisting of two nonswitching thin interface layers near the top and bottom electrodes. The difference in electrical conductivity between the two interface layers induces voltage offset and deformation behaviors in hysteresis loops.…
Abstract A new kind of pyridine‐containing aromatic diamine monomer, 4‐phenyl‐2,6‐bis[4‐(4‐aminophenoxy)phenyl]‐pyridine (PAPP), was successfully synthesized by a modified chichibabin reaction of benzaldehyde and a substituted acetophenone, 4‐(4‐nitrophenoxy)‐acetophenone (NPAP), followed by a reduction of the resulti…
The authors report size control of catalytic nanoparticles by thermal annealing for diameter-controlled growth of single-walled carbon nanotubes (SWNTs). They found that Co nanoparticle-size gradually decreased through repetitive annealing at 1000°C in Ar ambient. Results of x-ray photoelectron spectroscopy and second…
The authors conducted a comparative study of compressibility between nanocrystalline and bulk nickel using synchrotron x-ray diffraction at pressures up to 7.4GPa. Their results present a clear evidence of elastic softening in nanocrystalline Ni as compared with the bulk nickel. It is also observed that the bulk modul…
Abstract A series of novel, linear, soluble, high‐molecular‐weight, fluorinated aromatic polymers has been obtained for the first time using a superacid‐catalyzed polyhydroxyalkylation reaction of fluorinated carbonyl‐containing compounds: 1,1,1,‐trifluoroacetone ( 1 ), 2,2,2‐trifluoroacetophenone ( 2 ), 2,3,4,5,6,‐pe…
Recently, there is increasing interest in using superelastic shape memory alloys (SMAs) in civil, mechanical and aerospace engineering, attributed to their large recoverable strain range (up to 6–8%), high damping capacity, and excellent fatigue property. In this research, an improved Graesser's model is proposed to m…