Materials Literature
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X-ray diffraction, neutron diffraction, and susceptibility measurements were performed on ${}^{7}{\mathrm{LiMn}}_{2}{\mathrm{O}}_{4}$ powder specimen. The Jahn-Teller lattice distortion induces a phase transition from cubic to orthorhombic structure at $T=283.5\mathrm{K}$ on cooling. A series of well-defined magnetic…
Abstract A blend system prepared from epoxy resin (EP) and polyurethane (PU) was investigated in terms of glass‐transition temperature ( T g ), contact angle, mechanical interfacial, and mechanical properties. Deionized water and diiodomethane were chosen as the angle testing liquids. In this work, the models of Owens…
Abstract Dissolution of Antheraea pernyi silk fiber was carried out in a calcium nitrate solution with various dissolving conditions. The solubility was significantly dependent on the concentration of calcium nitrate, dissolving temperature, and time. The proper conditions of dissolution were found as 7 M calcium nitr…
The development of lead zirconate titanate (PZT)-based capacitors has been a long time goal of ferroelectric random access memories (FRAM). However, PZT-based perovskites with common platinum (Pt) electrodes have suffered from a significant reduction of the remanent polarization (Pr) after a certain number of read/wri…
Piezoelectric investigations of 〈011〉-oriented Pb(Mg1/3Nb2/3)O3–PbTiO3 (PMN–PT) and Pb(Zn1/3Nb2/3)O3–PbTiO3 (PZN–PT) crystals have revealed high electromechanical properties. Piezoelectric constants of up to 5000–6000 pC/N and electromechanical coupling coefficients of up to 0.95 have been observed near the ferroelect…
The quantum-confined Stark effect in a single self-assembled CdSe/ZnSe quantum dot was studied by means of highly spatially resolved photoluminescence spectroscopy. A nanotechnological approach making use of a capacitor-like geometry enabled us to apply a well-defined lateral electric field on the quantum dots. Stark…
The field-emission mechanism of open-ended single-walled carbon nanotubes (SWNTs) is studied. Owing to electronic effects that directly alter the bonding mode and remarkably influence the work function, an open-ended SWNT has much better field-emission properties than a closed SWNT; owing to geometrical effects that s…
Xenopus oocytes assemble an array of F-actin and myosin 2 around plasma membrane wounds. We analyzed this process in living oocytes using confocal time-lapse (four-dimensional) microscopy. Closure of wounds requires assembly and contraction of a classic "contractile ring" composed of F-actin and myosin 2. However, thi…
A potential disadvantage of real-space-grid electronic structure methods is the lack of a variational principle and the concomitant increase of total energy with grid refinement. We show that the origin of this feature is the systematic underestimation of the kinetic energy by the finite difference representation of t…
We present the circuit equivalent of the Landau-Khalatnikov dynamical ferroelectric model. The differential equation for hysteretic behavior is subject to numerical computer simulations. The size and shape of the simulated hysteretic loops depends strongly on the frequency and the amplitude of the driving electric fie…
Highly ordered hexagonal arrays of parallel metallic nanowires (Ni, Bi) with diameters of about 50 nm and lengths up to 50 μm were synthesized by electrodeposition. Hexagonal-close-packed nanochannel anodized aluminum oxide film was used as the deposition template. The deposition was performed in an organic bath of di…
Abstract Triglyceride oils derived from plants have been used to synthesize several different monomers for use in structural applications. These monomers have been found to form polymers with a wide range of physical properties. They exhibit tensile moduli in the 1–2 GPa range and glass transition temperatures in the…
3d-transition-metal-doped ZnO films (n-type Zn1−xMxO (x=0.05–0.25): M=Co, Mn, Cr, Ni) are formed on sapphire substrates using a pulsed-laser deposition technique, and their magnetic and electric properties are examined. The Co-doped ZnO films showed the maximum solubility limit. Some of the Co-doped ZnO films exhibit…
The photoluminescence (PL) spectra of the undoped ZnO films deposited on Si substrates by dc reactive sputtering have been studied. There are two emission peaks, centered at 3.18 eV (UV) and 2.38 eV (green). The variation of these peak intensities and that of the I–V properties of the ZnO/Si heterojunctions were inves…
ADVERTISEMENT RETURN TO ISSUEPREVCommunication to the...Communication to the EditorNEXTChemoselective Ring-Opening Polymerization of a Lactone Having exo-Methylene Group with Lipase CatalysisHiroshi Uyama, Shiro Kobayashi, Masatake Morita, Shigeki Habaue, and Yoshio OkamotoView Author Information Department of Materia…
The temperature dependence of the DC resistivity of silver quantum dot self-assembled 2D Langmuir monolayers was obtained. The films exhibit a metallic-like resistance at high temperatures (above 200 K), and a thermally activated mechanism at intermediate temperatures (60−200 K) which strongly supports the model of a…
Triblock polymers, poly(ethylene oxide-b-propylene oxide-b-ethylene oxide) (PEO-b-PPO-b-PEO), are used as molecular templates in poly(methyl silsesquioxane) (MSQ) matrixes to fabricate nanoporous organosilicates. The triblock copolymers microphase-separate into nanometer domains as the MSQ matrix becomes increasingly…
A two-dimensional self-consistent-field lattice model incorporating the rotational isomeric state scheme to account for chain rigidity was developed to study the phase diagram of rod−coil diblock copolymer melts. Several morphologies such as lamella, zigzag lamella, elliptical cross-sectional cylinders, and hexagonall…
ADVERTISEMENT RETURN TO ISSUEPREVCommunication to the...Communication to the EditorNEXTDivergent Synthesis of Dendronized Poly(p-hydroxystyrene)Scott M. Grayson and Jean M. J. FréchetView Author Information Center for New Directions in Organic Synthesis,† Department of Chemistry, University of California, Berkeley, Ca…
A novel, wet chemical approach is reported for the facile synthesis of silver nanowires with diameters in the range of 20−40 nm in aqueous solutions of a double-hydrophilic block copolymer (DHBC) PEO-b-PMAA. Investigation of the time-dependent formation of the silver nanowires revealed that they were produced through…