Materials Literature
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On nanotextured noble-metal surfaces, surface-enhanced Raman scattering (SERS) is observed, where Raman scattering is enhanced by a factor, G, that is frequently about one million, but underlying the factor G is a broad distribution of local enhancement factors, eta. We have measured this distribution for benzenethiol…
Thin films of polytetrafluoroethylene (PTFE) were deposited by pulsed electron deposition (PED) technique. X‐ray diffraction of the room temperature deposited film shows crystalline nature. The molecules are oriented with chain axis parallel to the substrate surface, and the film had preferential crystal orientation w…
A particle-swarm optimization (PSO) algorithm was developed for designing binary-phase-only diffractive optical elements (DOEs) that superresolve the axially focused point-spread function. The method is based on vector diffraction theory to ensure solutions are valid under high-NA conditions. A DOE is identified that…
We calculate the plasma excitations in a bundle as well as a two-dimensional (2D) periodic array of aligned parallel multishell nanotubes on a substrate. The carbon nanotubes are oriented perpendicular to the substrate. The model we use for the system is an electron gas confined to the surface of an infinitely long cy…
Strain can effectively modulate the structure and properties of single-walled carbon nanotubes (SWNTs), and hence is an important aspect in their researches and applications. In this article, the effect of torsional strain on the G -band modes of individual SWNTs is reported. When torsional strain is induced by atomic…
First-principle total-energy calculations show that a ferrimagnetic state is most stable in Mn 2 YZ (Y = Cr and Mn) with the Heusler structure and that among them there are highly spin-polarized ones with magnetic moments of 0, 1, and 2µ B per formula unit. Electronic structures of nonstoichiometric alloys suggest tha…
The kinetics of the miniemulsion copolymerization of styrene (St) and γ-methacryloxypropyltrimethoxysilane (MPS) was investigated by studying the effects of the MPS/St weight ratio, the nature and amount of initiator, the suspension pH, and the surfactant concentration on the overall and individual monomer conversions…
A molecular theory of the smectic A–smectic C transition in a system of biaxial molecules is developed in the mean-field approximation. The influence of molecular biaxiality on the transition is considered in detail and it is demonstrated how the biaxial order parameters are induced by the tilt. It is shown that the o…
Movement of solid crystals in the form of dendrite fragments causes severe macro-segregation in solidified products. Dendrite fragmentation in the developing mushy zone occurs as a result of remelting (causing dissolution) and subsequent breakage of dendritic side arms from the \ndendritic stalks. An understanding…
We report the results of first-principle calculations on Bi nanowires and nanotubes oriented along the [012] direction. The shapes of the cross section have an important effect on the stability of Bi nanowires resulting from different reconstructions. Among the Bi nanowires studied, the most stable ones have the core−…
Various PbSe hierarchical superstructures, including the PbSe octopod hierarchitectures densely/loosely stacked by cubic building units, and PbSe windowlike hierarchitectures, have been achieved from the PbSe cubes by the alkaline etching methodology. This work indicates that the complicated hierarchical superstructur…
PbS nanocrystals with different shapes were synthesized at the air/PbCl 2 aqueous solution interface via reaction between Pb 2+ and H 2 S gas under poly(9-vinylcarbazole) (PVK) thin films and characterized by transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), electron dif…
La 0.67 Ca 0.33 MnO 3 (LCMO) films of 6–60 nm thickness were grown epitaxially on orthorhombic NdGaO 3 (1 1 0) Or (NGO) substrates by the pulsed laser deposition method. Like NGO, the films when relaxed should also have an orthorhombic structure that can be described by a pseudocubic perovskite unit, with the angle β…
The impact of ultraviolet radiation (UVR) on a semi-natural, soft-bottom diatom community from Potter Cove, King Georg Island, Antarctica, was investigated. The objective was to estimate the impact of UV-B (280 to 320 nm) and UV-A (320 to 400 nm) on photosynthetic efficiency, pigments, DNA damage and repair. The diato…
A high-affinity, binary Eu(3+) receptor site consisting of 1,4,7,10-tetraazacyclododecane-1,7-diacetate (DO2A) was constructed with the goal of improving the detection of dipicolinic acid (DPA), a major component of bacterial spores. Ternary Eu(DO2A)(DPA)(-) complex solutions (1.0 microM crystallographically character…
We synthesized Ge and Ge 1− x M x (M = Mn, Co, and Fe, x ≤ 0.4) nanowires using the thermal vapor transport method. All of the nanowires consisted of single-crystalline Ge nanocrystals grown uniformly with the [111] direction. High-resolution X-ray diffraction showed no metal cluster formation for any of the Ge 1− x M…
Abstract PS/PMMA blends were prepared using a twin screw extruder and then extruded using an electromagnetic dynamic plasticating extruder equipped with a specially designed split die. During dynamic plasticating extrusion, the dynamic rheological behavior of PS/PMMA blends was investigated. The extrudates were cooled…
We have developed bandpass filters for long mid-infrared astronomy in 25 to 40μm. Most of materials become opaque in wavelengths longer than 25μm. We have applied the metal mesh method to make filters of non-transparent materials. The mesh patterns are designed based on the FDTD calculations and fabricated by th…
A high pressure wire mesh reactor has been modified to investigate the reactions underlying the zero emission carbon concept (ZECA) process. This is a novel power generation concept that involves producing hydrogen from coal. An earlier paper has described the concept, the wire mesh reactor used for laboratory scale t…
Abstract This paper uses a finite element analysis to investigate the morphological changes of nano-cells in a polystyrene (PS) – CO 2 foaming system. The system was composed of a finite polymer melt with a central cell and eight surrounding cells. The computational domain was discretized using linear triangular eleme…