Materials Literature
按标题、摘要、年份、主题和来源检索公开元数据。结果保留作者、摘要、分类与原始来源链接。
The structure of a decagonal Al72Ni20Co8 quasicrystal with space group P10(5)/mmc has been determined on the basis of a single-crystal X-ray data set using the five-dimensional description. The best-fit model structure based on a cluster model having lower symmetry than the decagonal symmetry with 103 parameters gives…
Sol−gel polymerization of organotrialkoxysilanes RSi(OR‘) 3 and formation of silsesquioxane (SSQO) structures was followed using SEC, 29 Si NMR, and both small- and wide-angle X-ray scattering. Evolution of the SSQO structure is controlled by the competition between intermolecular polycondensation and cyclization. A s…
Abstract An elastomeric polyurethane/clay (PU/clay) nanocomposite based on poly(propylene glycol) (PPG), glycerol propoxylate, and toluene‐diisocyanate (TDI) was synthesized by intercalative polymerization technology. The results of wide angle X‐ray diffraction (WAXD) studies showed that the gallery distance of the cl…
ADVERTISEMENT RETURN TO ISSUEPREVCommunicationNEXTThermally and Photochemically Triggered Self-Assembly of Peptide HydrogelsJoel H. Collier, Bi−Huang Hu, Jeffrey W. Ruberti, Jerry Zhang, Pochi Shum, David H. Thompson, and Phillip B. MessersmithView Author Information Northwestern University Biomedical Engineering Depa…
We report the polarized optical absorption spectra of single-walled 4 A carbon nanotubes arrayed in the channels of an AlPO (4)-5 single crystal. When the light electric field (E) is polarized parallel to the tube direction (c), the spectra display a sharp peak at 1.37 eV, with two broadbands at 2.1 and 3.1 eV. In the…
Abstract Crosslinked sodium polyacrylate as a superabsorbent was prepared by inverse suspension polymerization with cyclohexane as the continuous phase and sorbite anhydride monostearic acid ester (span‐80) as the dispersant. The crosslinking degree was regulated by NaOH. The distilled water absorbency (WA) of the pol…
The magnetic susceptibilities $\ensuremath{\chi}$ versus temperature T of powders and single crystals of the ambient-pressure (AP) and high-pressure (HP) phases of $(\mathrm{VO}{)}_{2}{\mathrm{P}}_{2}{\mathrm{O}}_{7}$ are analyzed using an accurate theoretical prediction of $\ensuremath{\chi}{(T,J}_{1}{,J}_{2})$ for t…
Using Monte Carlo simulations and a mean-field theory, we study domain growth in a driven lattice gas. Mediated by a single vacancy, two species of particles (``charges'') unmix, so that a disordered initial configuration develops charge-segregated domains which grow logarithmically slowly. An order parameter is defin…
We have performed a first-principles study of the structural and vibrational properties of the three low-pressure (cubic, tetragonal, and especially monoclinic) phases of ZrO2, with special attention to the computation of the zone-center phonon modes and related dielectric properties. The calculations have been carrie…
A variety of fullerene molecules are found to be fully packed in the interior space of a single-wall carbon nanotube (SWNT) and form a novel one-dimensional crystal with a regular intermolecular distance. Using electron diffraction, we have successfully measured the ``lattice constants'' for these crystals of various…
We prepared polycrystalline samples of NaCo2-xMxO4 substituted for the Co site by other 3d or 4d elements (M=Mn,Cu, Zn, Ru, Rh, and Pd). While some of the elements (M=Mn,Ru and Rh) act as a strong scatterer to give rise to a rapid increase in resistivity, the others (M=Cu, Zn and Pd) do not deteriorate the electric co…
Diffraction patterns for polydisperse systems of crystalline grains of cubic materials were calculated considering some common grain shapes: sphere, cube, tetrahedron and octahedron. Analytical expressions for the Fourier transforms and corresponding column-length distributions were calculated for the various crystal…
The broad, intense peak found near 29 kDa in the laser-desorption mass-spectral abundances of various aurothiol (Au: SR) cluster compounds has been used to optimize the preferential formation of the species in that mass range. Recrystallization gives enriched fractions, on the 10 mg scale, that in several cases appear…
This paper examines the hypothesis that surfaces resistant to protein adsorption should also be resistant to the adhesion of bacteria ( Staphylococcus aureus, Staphylococcus epidermidis ) and the attachment and spreading of mammalian cells (bovine capillary endothelial (BCE) cells). The surfaces tested were those of s…
The fundamental physical properties of doped ${\mathrm{LaMnO}}_{3},$ generically termed ``manganites,'' and much of the underlying physics, were known more than 40 years ago. This article first reviews progress made at that time, the concept of double exchange in particular, and points out the missing elements that ha…
ADVERTISEMENT RETURN TO ISSUEPREVNoteNEXTSynthesis of Homo- and Heteroprotected Furcated Units for Modular ChemistryAdi Dahan and Moshe PortnoyView Author Information School of Chemistry, Raymond and Beverly Sackler Faculty of Exact Sciences, Tel-Aviv University, Tel-Aviv 69978, Israel [email protected]Cite this: J. O…
The multiwavelength anomalous diffraction (MAD) method for phase evaluation is now widely used in macromolecular crystallography. Successful MAD structure determinations have been carried out at the K or L absorption edges of a variety of elements. In this study, we investigate the anomalous scattering properties of u…
The photoreaction of xanthone in an alcoholic solution flowing through a column reactor filled with the mesoporous silica MCM-41 was performed. It was found that the product yields depend greatly on both the pore size of the filler and the nature of the solvent. The product yields of this reaction, which involves a pa…
Abstract A complex of trivalent lanthanum stearate with stearin (REC) was used as a surface modifier to treat calcium carbonate, and its efficacy was assessed. The measurement of the viscosity of a CaCO 3 /liquid paraffin suspension demonstrated that REC treatment could considerably improve the dispersion of filler in…
Mode contributions of different collective excitations to the density-density time correlation function in liquid lead are studied within the nine-variable approach of generalized collective modes. It is shown, that a kinetic relaxing mode, caused by slow density fluctuations, defines almost completely the shape of de…