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。
Intumescent chemical systems are designed to swell into a thick, robust foam upon exposure to heat, protecting the underlying material from fire by providing a physical barrier to heat and mass transfer. The mechanisms determining the fire-resistant properties of these materials are not well understood. Various approa…
A powerful, compact, and repetitive flash x-ray system based on a cable transformer technology powered by ceramic capacitors in a Blumlein-like configuration has been developed. Open circuit voltages in excess of 100 kV can be achieved while commutation occurs at low voltage (<20 kV). The x-ray emission from a…
Monodisperse soap bubbles introduced into a glass cylinder form ordered foam structures whose liquid fraction may be varied by the steady supply of the solution at the top. We report observations of moving boundaries in these structures. They include a 180° twist boundary, which was unanticipated and still not fully u…
Abstract It is often observed that the photochemical degradation of titanium dioxide pigmented PVC leads to a latent discoloration that is revealed only during a further period of storage of the aged material in the dark. This effect is reversible, and photobleaching can be provoked by a new irradiation of the polymer…
Substituting Cd 2+ ions into the A and B sites in a Pb(Ni 1/3 Nb 2/3 )O 3 PbZrO 3 PbTiO 3 (PNNPZPT) ternary perovskite material made it possible to determine the effects of the Cd 2+ ion substitution site on sintering behavior. The substitution site of the Cd 2+ ion was identified by using X‐ray photoelectron spectros…
Dielectric measurements have been performed on a KTN ceramic with composition KTa0.6Nb0.4O3 under various dc bias electric fields E. The temperature and field dependences of ε′r and tan δ are related to the presence of polarization fluctuations. Around TC, ε′r exhibits a nonlinearity following the relationship: ε′r =…
This article describes a strategy for suppressing the coalescence of cells during shaping in continuous processing of microcellular plastics. Microcellular plastics are foamed polymers characterized by a cell density greater than 10 9 cells/cm 3 and fully grown cell size on the order of 10 μm. Since the invention of m…
Initiation of a corrosion pit in plain carbon steel (CS) was simulated by preconditioning a small area and a larger concentric area as an anode and cathode, respectively. Preconditioning was achieved by applying a galvanic current between the electrodes. During this initial step, the effect of sulfate-reducing bacteri…
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…