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。
Abstract The Raman and infrared spectra of the superionic protonic conductor CsHSO 4 (CsDSO 4 ) were investigated in the 18–450 K range. Polarized single crystal Raman and infrared reflection spectra were also studied at room temperature. An assignment of bands due to internal and external vibrations is given in terms…
FeCr alloys with concentrations ranging from 50 p.p.m. to 3% Cr have been irradiated with electrons of 1.6 MeV at low temperature (30 K) and studied by resistivity measurements. Pre-irradiation measurements show important deviations from Matthiessen's rule in the annealed alloys: the resistivity increment per unit con…
A new type of liquid crystals made up of bowl-like molecules was predicted by Lin in 1982 and was recently synthesized. In is paper, the experimental findings about these bowlic mesophases are briefly summarized. Possible mesophases (polar nematic, non-polar nematic, cholesteric, stringbean, donut, columnar, etc.) are…
Abstract ESCA and contact angle measurements were used to characterize the surfaces of Polyethylene and polypropylene films exposed to SF 6 , CF 4 , and C 2 F 6 plasmas. None of these gases polymerized in the plasma. However, all plasma treatments grafted fluorinated functionalities directly to the polymer surfaces. S…
We have measured the phase diagrams of mixtures of chiral and racemic CE4, CE5, and CE2 in order to study the effect of varying chirality on the existence of blue phases in chiral liquid crystals. We observe three blue phases---BPI, BPII, and BPIII---which progressively appear at the isotropic phase boundary as the ch…
Energetic ion-beam irradiation of diamondlike carbon thin films induces a decrease of 5–6 orders of magnitude in the resistivity of the films from their as-grown value of 107 Ω cm. Diagnostics used to characterize the nature of the transformation included optical absorption measurements (band gap), Raman spectroscopy…
Research Papers The Melting Process Within Spherical Enclosures S. K. Roy, S. K. Roy University of Miami, Coral Gables, FL 33124 Search for other works by this author on: This Site PubMed Google Scholar S. Sengupta S. Sengupta University of Miami, Coral Gables, FL 33124 Search for other works by this author on: This S…
Binuclear copper(11) complexes of fatty acids crystallize at room temperature in a lamellar lattice that has been characterized by X-ray diffraction. A transition to a thermotropic columnar mesophase is observed at about 110-120°C for each compound of the series n = 12 to n = 22, n being even and equal to the number o…
Raman spectra of iron phosphorus trichalcogenide crystals (FeP${X}_{3}$,X=S,Se) are measured, and a compilation of the peak frequencies is given. The spectral features due to first-order phonon Raman scattering are analyzed and assigned. At low temperatures in iron phosphorus trisulfide the vibrational Raman-scatterin…
ADVERTISEMENT RETURN TO ISSUEPREVArticleCorrelation between the glass transition temperatures of polymer mixtures and intermolecular force parametersT. K. Kwei, Eli M. Pearce, John R. Pennacchia, and M. ChartonCite this: Macromolecules 1987, 20, 5, 1174–1176Publication Date (Print):May 1, 1987Publication History Publi…
The effects of carbon on the magnetic properties of steel have been of great interest over the years both because of the great commercial importance of steel and because it is known that carbon is the most important single factor affecting the magnetic properties of steel. Slight changes in the amount and distribution…
Nonlinear calibration curves of weight fraction vs integrated intensity ratio arc obtained for polymorphic mixtures of ZrO 2 by means of powder X‐ray diffraction. The (C + M) and (T + M) ZrO 2 systems are analyzed using the {111} reflections. Intensity ratios in mixtures prepared with an ultrafine m ‐ZrO 2 powder agre…
Abstract Polymer‐polymer blends offer a route for enhancement of various properties. When immiscible polymers are blended together (in the presence of a compatibilizer), the blend properties are dependent on the morphology of the phases. Uniform, fine dispersions generally result in “average” properties. Discussed her…
Abstract The surface‐enhanced Raman (SER) spectra of aromatic amino acids ( L ‐phenylalanine, L ‐tyrosine and tryptophan) and their glycyl dipeptides (glycyl‐ L ‐phenylalanine, glycyl‐ L ‐tyrosine and glycyl‐ L ‐tryptophan) adsorbed on Ag colloidal particles have been obtained. The surface‐enhanced and ordinary Raman…
The crystal structure of human ubiquitin has been solved by x-ray diffraction methods and refined by standard procedures to a conventional crystallographic R factor of 0.176 at 1.8-A resolution (Vijay-Kumar, S., Bugg, C.E., and Cook, W.J. (1987) J. Mol. Biol. 194, 525-538). Crystals of yeast and oat ubiquitin have bee…
The charge-dependent ‘‘effective’’ electronegativity χα of an atom α in a molecule or crystal, i.e., χα=(χ0α+Δχα)+2(η0α +Δηα)qα +∑β≠α qβ/Rαβ differs from the expression for the isolated atom (χ0α+2η0αqα) because of corrections to the electronegativity (Δχα) and hardness (Δηα), respectively, and due to the external pot…
More than two decades ago, Bonner reported the first preparation of poly (aromatic ketones) (PAK) by aluminum chloride-catalyzed acylation of diphenyl ether with aromatic diacid chlorides [1]. These were low molecular weight materials because of solubility limitations. In the intervening years, significant progress ha…
Gram-negative, aerobic bacteria capable of facultative growth using ferric ions or thiosulfate or sulfite as electron acceptors were readily isolated from oil field fluids. Morphological and biochemical data are presented which support the classification of these isolates as being strains of Alteromonas putrefaciens (…
One of the major causes of magnesium corrosion is the presence of iron as an impurity in commercial alloys. Alloying the material with manganese may reduce the corrosion rate to acceptable levels. The corrosion rate of a Mg-9% Al-1% Zn alloy, containing varying amounts of Mn and Fe, correlates with the Fe:Mn ratio in…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTHighly stabilized copper(III) complexesFred C. Anson, Terrence J. Collins, Thomas G. Richmond, Bernard D. Santarsiero, James E. Toth, and Brian G. R. T. TrecoCite this: J. Am. Chem. Soc. 1987, 109, 10, 2974–2979Publication Date (Print):May 1, 1987Publication History Publishe…