Materials Literature
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Using first-principles total energy calculations, we have investigated the structure and phase stability of spinel-based transition aluminas $(\ensuremath{\gamma},\ensuremath{\delta},\ensuremath{\eta}),$ both in the presence and absence of hydrogen. The spinel-based structures (formed from dehydration of aluminum hydr…
We find that the electronic dispersion in graphite gives rise to double resonant Raman scattering for excitation energies up to 5 eV. As we show, the curious excitation-energy dependence of the graphite D mode is due to this double resonant process resolving a long-standing problem in the literature and invalidating r…
A transmission-type nonmechanical multiple-angle beam-steering device that uses liquid-crystal blazed grating has been developed. Sixteen steering angles with a contrast ratio of 18 has been demonstrated. A detailed analysis of the liquid-crystal and poly(methyl methacrylate) blazed-grating deflector was carried out t…
We consider a system of trimers and monomers on the triangular lattice, which describes the adsorption problem on (111) $1 \times 1$ surface of diamond structure. We give a mapping to a 3-state vertex model on the square lattice. We treat the problem by the transfer-matrix method combined with the density-matrix algor…
Attenuated total reflection Fourier transform infrared studies of the electrochemical redox processes of poly(dithieno[3,4-b:2‘,3‘-d]thiophene) (pDTT3), a low band gap conjugated polymer with a “polythiophene-like” backbone, where an aromatic moiety is fused to each thiophene ring, are reported. Vibrational spectrosco…
The promoting roles of noble metals (Pt, Rh, and Pd) and NO x storage mechanism were investigated on alkaline earth metal oxide-based NO x storage catalysts under lean-burn conditions. It was found that noble metals increased the reaction rates of NO oxidation to NO 2 and nitrite oxidation to nitrate, resulting in an…
Two models based on electrooptical parameters and one model using the fixed-charge approximation are tested for the calculation of the infrared intensities of the vibrational modes deduced from molecular dynamics calculations of four siliceous zeolites: sodalite, faujasite, zeolite A, and silicalite. The best results…
Porous titania microspheres with a very narrow particle size distribution (PSD) were synthesized by polymerization-induced colloid aggregation (PICA). After being sintered, the titania microspheres that are obtained have an average diameter of 3.5 microm, a surface area of 36.7 m2/g, an average pore volume of 0.30 mL/…
Using Au nanoparticles, it is possible under certain experimental conditions to considerably enhance the sensitivity of a conventional surface plasmon resonance (SPR) device. In this report, we examine the mechanism of this enhancement and discuss the experimental factors that are crucial to the performance of such a…
The fabrication of magnetic composite core−shell particles and hollow spheres with tailored dimensions and compositions has been accomplished by a multistep (layer-by-layer) strategy. Composite particles were prepared by coating submicrometer-sized anionic polystyrene (PS) latices with magnetite (Fe 3 O 4 ) nanopartic…
ADVERTISEMENT RETURN TO ISSUEPREVCommunicationNEXTFormation of High-Quality CdTe, CdSe, and CdS Nanocrystals Using CdO as PrecursorZ. Adam Peng and Xiaogang PengView Author Information Department of Chemistry and Biochemistry University of Arkansas, Fayetteville, Arkansas 72701 Cite this: J. Am. Chem. Soc. 2001, 123,…
Variable-temperature synchrotron x-ray powder diffraction data from dehydrated Na6[Al6Si6O24] reveal a structural phase transition that involves both the commensurate ordering of the extra-framework Na cations and a one-dimensional incommensurate modulation of the framework. Peak splittings and superlattice reflection…
Polypropylene hollow fibers were produced via the spunbonding process. Nitrogen gas was used as the lumen fluid. The polypropylene continuity equation can be combined with the nitrogen continuity equation to give excellent predictions of the inside diameter and the outside diameter of the product fiber. Tests were dev…
We have reported previously on the expression of recombinant human type X collagen (hrColX) in HEK 293 and HT 1080 cells by using the eukaryotic expression vector pCMVsis (in which CMV stands for cytomegalovirus). Several stably transfected clones secreted full-length triple-helical hrColX molecules in large amounts,…
A method is presented for modeling the geometrical packing of polydisperse mixtures of both spherical and nonspherical particles, which are models for filler particles used in the manufacture of polymer composites. The technique is based on the calculation of the dissipative dynamics of an ensemble of fused soft spher…
ADVERTISEMENT RETURN TO ISSUEPREVCommunicationNEXTA Solution Low-Temperature Route to MoS2 FiberHongwei LiaoHongwei LiaoDepartment of Chemistry and Structure Research Laboratory, University of Science & Technology of China, Hefei, Anhui 230026, Peoples' Republic of China More by Hongwei Liao, Yanfei WangYanfei WangDep…
The giant optical nonlinearity associated with photoinduced molecular reorientation of dye-doped nematic liquid crystals has been measured for a homologous set of dyes belonging to the anthraquinone family, dissolved both in a polar and in a nonpolar liquid crystal host. We found a strong sensitivity of the nonlineari…
ADVERTISEMENT RETURN TO ISSUEPREVCommunicationNEXTThe Formation of Dimensionally Ordered Silicon Nanowires within Mesoporous SilicaNicholas R. B. Coleman, M. A. Morris, Trevor R. Spalding, and Justin D. HolmesView Author Information Department of Chemistry and Supercritical Fluid Centre University College Cork, Cork,…
The demixing of a 0.002 wt % solution of a poly(ε-caprolactone) chain ( M w = 20 000; M w / M n = 1.07), labeled at both chain ends with pyrene, in tetrahydrofuran (THF) was studied using fluorescence. The very diluted region of the phase diagram of small polymer chains was explored for the first time. The coexistence…
A series of ternary and quaternary R-phase compounds in the Li-Mg-Zn-Al system are synthesized from pure elements in sealed Ta tubes with starting compositions based on the suggestions from electronic structure calculations using relative Mulliken populations to quantify the site preferences for the various elements.…