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。
Structure factors with known magnitude and phase are constructed for seven different molecular crystals in non-centrosymmetric space groups and used to calibrate the retrieval of structure-factor phase information with several different scattering factor models. Monopole models are confirmed to be inadequate, yielding…
Miscibility and an asymmetric T g −composition relationship have been demonstrated in the binary blends composed of amorphous poly(ether imide) (PEI) and semicrystalline poly(butylene terephthalate) (PBT). The peculiar T g −composition behavior in the miscible PEI/PBT blends was analyzed using a free-volume approach,…
Abstract The synthesis of a bifluorophoric perylene dye ( 4a ) is described, in which the two chromophores are linked by a chiral binaphthyl unit. A strong exciton coupling of the two chromophores, a bathochromically shifted fluorescence and strong CD effects are observed. The structure of 4 is compared to the photosy…
The effect of enhanced atomic mobility on the growth of hard carbon films was examined. Tetrahedrally bonded amorphous carbon films were deposited by condensing energetic carbon ions using an arc-discharge deposition method. The deposition temperature varied between 50 and 400 °C. The dependence of elastic properties…
Charging processes on the bulk oxides Al2O3, ZrO2 and SiO2 occurring during Auger Electron Spectroscopy (AES) are studied. All samples experience a negative charge-up under the following parameters: electron beam energy >1 keV, current density >10-2 A cm-2 and different angles of incidence. The samples show strong his…
Fast relaxational motions in glassy PMMA were investigated through quasielastic neutron scattering. As previously found with quasielastic light scattering, the corresponding relaxation time, which is of the order of 10 −11 s, is only slightly temperature dependent, while the relaxational signal intensity increases rap…
Low-frequency excitations (LFE's) of disorder modes were investigated in (1-x-y)${\mathrm{SiO}}_{2}$\ensuremath{\cdot}${\mathrm{yP}}_{2}$${\mathrm{O}}_{5}$\ensuremath{\cdot}${\mathrm{xLi}}_{2}$O glasses by means of $^{7}\mathrm{Li}$ and $^{31}\mathrm{P}$ nuclear-spin relaxation (NSR) and ac conductivity experiments co…
Abstract Formation processes of weathering products of pumice collected from a rhyolitic pyroclastic flow deposit were investigated by X-ray powder diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and energy dispersive X-ray analysis (EDX). SEM clearly showed the presence o…
Abstract Low‐density polyethylene (LDPE) composites containing untreated cellulose, cellulose treated with cellulase, and cellulose treated with cellulase after pretreating with NaOH were prepared. The purpose of the cellulase treatment of cellulose is to enhance the interfacial adhesion between the cellulose and the…
The number- and weight-average molecular weights of several statistical and high ortho novolac resins were determined using gel permeation chromatography (GPC). The standards used were pure compounds having between 2 and 12 phenol units bridged via methylene linkages. Three series of compounds were studied: (i) those…
Other| June 01, 1997 Na, K, Rb, and Cs exchange in heulandite single crystals; diffusion kinetics Ping Yang; Ping Yang Universitaet Bern, Laboratorium fuer Chemische und Mineralogische Kristallographie, Bern, Switzerland Search for other works by this author on: GSW Google Scholar Jano Stolz; Jano Stolz Search for oth…
It is proposed that the reactions of hexamethylenetetramine (HMTA) with 2,4-xylenol and with 2,6-xylenol occur by different pathways. The rate of reaction and the final product distribution depend on the initial xylenol : HMTA ratio and are different in the two systems. Measured by HMTA consumption, with 2,4-xylenol t…
The strengths of ceramic fibers and whiskers have been observed to increase with decreasing fiber diameter and length. Typically, both surface flaws and volume flaws exist in ceramic fibers and whiskers, which makes it impossible to characterize the strength dependence of both the diameter and the length with a single…
An electron acceptor moiety based on the 4,5-dinitro-1,8-naphthalenedicarboximide system has been prepared and used as the basis for synthesis of a porphyrin−imide dyad (P−NIm) and a carotenoid−porphyrin−imide triad molecule (C−P−NIm). Excitation of the porphyrin moiety in either compound with visible light leads to r…
The effect of repeated radiative energy transfer on the observed excited-state lifetime τobs of a luminescent species in a solid is studied by Monte Carlo simulations. Increasing the sample path length, the reabsorption coefficient, or the luminescence quantum yield significantly lengthens τobs relative to its intrins…
Summary In semi‐arid tropics soil hardening may reduce both water infiltrability and biological activity, thus inducing the development of large almost bare areas. A sandy‐loam soil with contrasting loose and underlying hard horizons was studied in the southern plain of the Chad basin. The fabrics of these horizons we…
The transaminase activity of two new semisynthetic RNase-S proteins incorporating a pyridoxamine moiety at the active site has been evaluated. A chemically competent derivative of pyridoxamine phosphate was incorporated into the C-peptide fragments of these non-covalent protein complexes in the form of an unnatural co…
Bulk samples of nanocrystalline Ni were produced by severe plastic deformation consolidation of ball-milled powders. The processed samples are characterized by reduced values of saturation magnetization and Curie temperature. Relying on transmission electron microscopy and X-ray data, an assumption has been made to ex…
ADVERTISEMENT RETURN TO ISSUEPREVCommunicationNEXTRemarkable Heteroatom Dependence of the Spin Multiplicity in the Ground State of 9,9'-(m-Phenylene)dixanthyl and -dithioxanthyl DiradicalsKeiji Okada, Takaaki Imakura, Masaji Oda, Atsushi Kajiwara, Mikiharu Kamachi, and Masakazu YamaguchiView Author Information Departm…
An organic nonlinear optical crystal, 5-nitro-2-thiophenecarboxaldehyde-4-methylphenylhydrazone (NTMPH), has been prepared and investigated with regard to polymorphism, growth, and characterization of the structural and physical properties. Recrystallization of NTMPH in various solvents under different conditions show…