Materials Literature
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Recent experiments showed that the last, single channel conductance step in monatomic gold contacts exhibits significant fluctuations as a function of stretching. From simulations of a stretched gold nanowire linked to deformable tips, we determine the distribution of the bond lengths between atoms forming the nanocon…
The vibrational density of states (VDOS) of nanoclusters and nanocrystalline materials are derived from molecular-dynamics simulations using empirical tight-binding potentials. The results show that the VDOS inside nanoclusters can be understood as that of the corresponding bulk system compressed by the capillary pres…
Circular dichroism (CD) spectra of chiral bare and thiol-passivated gold nanoclusters have been calculated within the dipole approximation. The calculated CD spectra show features that allow us to distinguish between clusters with different indexes of chirality. The main factor responsible of the differences in the CD…
In several series of sodium borosilicate glasses, we have applied triple-quantum magic-angle spinning (3QMAS) 11 B and 17 O NMR to obtain high-resolution information about short-range structure and the connections among various network structural units and their variations with composition. Oxygen-17 3QMAS spectra rev…
Uniform ceria nanocrystals with good crystallinity and high surface areas were prepared by a facile alcohothermal method with the addition of bases (KOH or NaOH), using Ce(III) or Ce(IV) salt as a starting material. The as-prepared nanocrystals were characterized by means of powder X-ray diffraction (PXRD), transmissi…
An intercalated polylactide (PLA)/layered silicate nanocomposite was prepared by simple melt extrusion of PLA and organically modified montmorillonite. The detailed crystallization kinetics and morphology of neat PLA before and after nanocomposite preparation were studied by using polarized optical microscopy, light s…
This paper describes a new test bench for measuring the modulation transfer function of an infrared focal plane array. The system is based on the use of a plane target made with a continuously self-imaging grating (CSIG) that projects in polychromatic light a biperiodic pattern of small and non-diffracting spots calle…
Selected spectral features of Raman spectra of glassy ${\mathrm{As}}_{2}{\mathrm{S}}_{3}$ subjected to elongation stress and sub-band-gap light illumination are analyzed and compared with polarization-dependent information obtained from the bulk glass at room temperature and near the glass transition temperature. The…
Abstract We have studied the vibrational properties of some of the compounds based on the Type II silicon, germanium, and tin‐based clathrate materials using LDA electronic structure methods. The lattices in these framework materials have open cages which can contain weakly bound guest impurities, and these guests pro…
Abstract A two-step method was developed for the large-scale synthesis of luminescent Y2O3:Eu nanobelts. The structure and composition of the as-prepared Y2O3:Eu were characterized by XRD, TEM, and EDX. The luminescent performance of the nanobelts was also characterized and the result was different from that of the ot…
Abstract Highly efficient photocycloreversion reaction was observed for diarylethene derivatives with cyano groups at the reactive carbons of the thiophene rings. The cycloreversion quantum yield of 1,2-bis(2-cyano-5-phenyl-3-thienyl)perfluorocyclopentene was found to be ca. 30 times larger than that of 1,2-bis(2-meth…
Adsorption isotherms of methane and ethane in single-walled carbon nanotubes (SWNTs) were measured by ${}^{1}\mathrm{H}$ nuclear magnetic resonance (NMR) at room temperature. It is shown that the interior of SWNTs becomes available for methane and ethane adsorption after cutting of SWNTs. Such endohedral adsorption do…
The perforation of a concrete target subjected to a rigid projectile impact is studied in this paper. Based on the dynamic cavity expansion theory and a plug formation model, semianalytical formulas for the perforation thickness and the perforation ballistic limit of concrete target are developed. The proposed formula…
Three new zeotiles , materials combining the advantages of micro‐ and mesoporous silica materials and capable of withstanding 300 °C, have been designed by tiling Silicalite‐1 nanoslabs. The Figure shows the projected silicate framework of one of the zeotiles in yellow, superimposed on a high resolution electron micro…
A structure analysis of Zn-Mg-Ho icosahedral quasicrystal was carried out by the powder X-ray diffraction method using synchrotron radiation (Lambda=0.73490 A) at SPring-8. The intensity distribution was analyzed by the Rietveld method modified for an icosahedral quasicrystal, in which simplified models were assumed:…
Structural studies on the icosahedral quasicrystals in Zn-Mg-Sc, Cu-Ga-Mg-Sc, and Zn-Mg-Ti alloys as well as their corresponding 1/1 cubic approximants, have revealed that these quasicrystals belong to a new structural group similar to Cd-based quasicrystals. This group is characterized by a triple-shell icosahedral c…
First-principles plane-wave pseudopotential calculations were performed to study electronic structures, structural relaxation, and energetics of intrinsic vacancies and interstitials in ${\mathrm{Al}}_{2}{\mathrm{O}}_{3}.$ In the presence of the intrinsic point defects, extra levels appeared in the band gap. Consideri…
The X-ray structures of [Os(bpy) 2 (CO)(Cl)][(PF 6 )] ( 1 ) and [Os(bpy) 2 (CO)(H)][(PF 6 )] ( 2 ) (where bpy = 2,2‘-bipyridine) have been solved. In complex 1, belonging to the C 2/ c space group, the Cl - and CO ligands are statically disordered along two almost orthogonal directions, and this disorder may be explai…
A general procedure, solvent-induced homogeneous dispersion, SIHD, is presented to incorporate and align conjugated polymers into a nematic liquid-crystal host. We report the investigation of the dye, N‘,N‘-bis(2,6 dimethylphenyl)-3,4,9,10, perylenetetracarboxylic dimide (PERY), and a conjugated polymer, poly[2-(2‘eth…
Thermal deformation behavior of Triaxial Woven Fabric (TWF) composites is modeled herein using Super-Finite-Elements proposed previously. Thermal deformation behavior and Thermal Expansion Coefficients (TECs) of the TWF composites are evaluated. Effects of the aspect ratios and size of the panels on the TECs are studi…