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。
High-resolution x-ray measurements have been performed at the synchrotron of LURE (Orsay) to study both uniaxial (discotic and calamitic) and biaxial nematic lyomesophases of the mixture K-laurate, 1-decanol, and D2O. The variations of the densitometric profiles of the diffracted bands are analyzed vs temperature. The…
The formation of oxide layers from porous silicon layers formed on P substrates which present different and well-controlled porous textures is studied in detail. It is shown that the overall process leading to oxides with properties similar to standard thermal oxides consists of two steps: the oxidation of silicon in…
The relation between grain size and grain‐boundary microcracking during cooling in aluminum titanate ceramics was studied. Microcracking temperature was determined by the measurement of thermal contraction and expansion, which was accompanied by acoustic emission. When the ceramics were cooled at a rate of 6°C/min, st…
The effects of experimental parameters on surface-enhanced Raman scattering (SERS) for silver-coated microsphere substrates were investigated. The parameters included sphere size, silver thickness, and excitation wavelength. The SERS signal intensity varied as each of these parameters was changed. The potential for in…
Using a generalized Landau type of free-energy density, we develop a theoretical model which, in a unified way, describes the general features of the tilt, polarization, pitch, dielectric susceptibility, and heat capacity of ferroelectric liquid crystals. Rewriting the equations into dimensionless form, we show that s…
The processing of interstellar dust grains by strong shock waves is studied, with the emphasis on the effects of grain-grain collisions. Such collisions provide the high pressures required to transform interstellar graphite and amorphous carbon grains into diamonds. Diamond metamorphism is as important for the destruc…
A phenomenological model of a vibrating 90°-domain wall in an electric and mechanic stress field is presented. The model allows to separate the domain wall and the volume contribution to the complex dielectric, piezoelectric and elastic constants. The results are compared with representative measurements of the above…
Specimens of 14C-labeled poly(ethylene terephthalate), nylon 66, and poly(methyl methacrylate) have been synthesized and exposed, in vitro, to a number of enzyme solutions. Poly(ethylene terephthalate) was found to be affected by esterase and papain, although in different ways, but not by trypsin or chymotrypsin. Nylo…
The distribution profile and quantity of charges in insulators have been studied by various methods, some of them utilizing thermal, mechanical, and electrical stimulations. A new method, incorporating pulse electric stimulations and pulse acoustic detection, is reported here along with preliminary results of the meas…
We report accurate temperature-dependent measurements of the optic index of refraction, the birefringence, and the strain in the ferroelectric, tungsten-bronze crystal ${\mathrm{Ba}}_{0.4}$${\mathrm{Sr}}_{0.6}$${\mathrm{Nb}}_{2}$${\mathrm{O}}_{6}$. This composition congruently melts, so large homogeneous high-quality…
We have developed a technique to measure the frequency-dependent specific heat of a liquid over a frequency range exceeding five decades, 0.01–3000 Hz. The measurement is not performed adiabatically, but rather relies on heat diffusion from a thin, planar heater immersed in the liquid sample. The spectrometer has been…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTElectrochromism of polyaniline film prepared by electrochemical polymerizationAkira Watanabe, Kunio Mori, Yasunori Iwasaki, Yoshiro Nakamura, and Shigeya NiizumaCite this: Macromolecules 1987, 20, 8, 1793–1796Publication Date (Print):August 1, 1987Publication History Publish…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTFluorescence and photoisomerization of azobenzene-containing bilayer membranesMasatsugu Shimomura and Toyoki KunitakeCite this: J. Am. Chem. Soc. 1987, 109, 17, 5175–5183Publication Date (Print):August 1, 1987Publication History Published online1 May 2002Published inissue 1…
Interface unbinding transitions, such as those arising in wetting phenomena, are studied in d dimensions with general interactions. Three scaling regimes must be distinguished: a mean-field (MF), a weak-fluctuation (WFL), and a strong-fluctuation (SFL) regime. A simple picture clarifies the origin and nature of the di…
Transmission electron microscopy was used to establish densification, alignment, and magnetization reversal mechanisms in hot-pressed and die-upset NdFeB magnets. Microstructures of these materials reveal two principal phases: Nd2Fe14B grains and a grain boundary phase of approximate composition Nd7Fe3. The grains in…
The cell surface topology of various gram-negative and -positive, anaerobic and aerobic, mesophilic and thermophilic, cellulolytic and noncellulolytic bacteria was investigated by scanning electron microscopic visualization using cationized ferritin. Characteristic protuberant structures were observed on cells of all…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTA new series of molecular semiconductors: phthalocyanine radicalsP. Turek, P. Petit, J. J. Andre, J. Simon, R. Even, B. Boudjema, G. Guillaud, and M. MaitrotCite this: J. Am. Chem. Soc. 1987, 109, 17, 5119–5122Publication Date (Print):August 1, 1987Publication History Publis…
Abstract The bulk polymerization of L , L ‐dilactide was studied as a function of polymerization temperature ( T p ), time and concentration of catalyst (tin 2‐ethylhexanoate). Poly( L ‐lactide) (PLLA), with the highest value of intrinsic viscosity ([η] = 13 dl · g −1 ; M̄ v ≈ 1 · 10 6 ) and heat of fusion (Δ H m = 64…
The chemically-synthesized emeraldine base form of polyaniline is soluble in aqueous acetic acid solutions, in which it presumably exists as the ‘doped’ emeraldine acetate salt. Films having a conductivity of ≈0.5 –2S/cm may be cast from the solutions. These films may be converted to relatively flexible, free-standing…
Gallium is a metal that literally melts in your hand. It has low toxicity, near-zero vapor pressure, and a viscosity similar to water. Despite possessing a surface tension larger than any other liquid (near room temperature), gallium can form nonspherical ...Read More