Materials Literature
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The author shows that the energy functional defined by Harris has a local maximum at the exact ground-state density of an electronic system provided the dielectric screening matrix of the system has eigenvalues that are all greater than unity.
Reference EPFL-ARTICLE-169118View record in Web of Science Record created on 2011-09-29, modified on 2017-11-27
Association structure of benthic diatoms in a hypersaline
UDPgalactose 4-epimerase from Escherichia coli is rapidly inactivated by the compounds uridine 5'-diphosphate chloroacetol (UDC) and uridine 5'-diphosphate bromoacetol (UDB). Both UDC and UDB inactivate the enzyme in neutral solution concomitant with the appearance of chromophores absorbing maximally at 325 and 328 nm…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTProposed mechanism for the condensation reaction of citrate synthase: 1.9-.ANG. structure of the ternary complex with oxaloacetate and carboxymethyl coenzyme AMihail Karpusas, Bruce Branchaud, and S. James RemingtonCite this: Biochemistry 1990, 29, 9, 2213–2219Publication Da…
The crystal structure of the ternary complex citrate synthase-oxaloacetate-carboxymethyl coenzyme A has been solved to a resolution of 1.9 A and refined to a conventional crystallographic R factor of 0.185. The structure resembles a proposed transition state of the condensation reaction and suggests that the condensat…
Abstract Thermal degradation of cotton, mercerized cotton, cotton grafted with vinyl acetate‐methyl acrylate mixtures at different compositions, and mercerized cotton grafted with vinyl acetate–methyl acrylate mixture at a composition of 60 : 40 has been investigated using the techniques of thermogravimetric analysis…
We have measured the time dependence of interface formation between two polymers, below their critical temperature for phase separation, using the $^{2}\mathrm{H}$${(}^{3}$He${,}^{4}$He${)}^{1}$H nuclear reaction as a direct profiling technique. We find that the width of the interface initially increases with time as…
Recent attempts at a microscopic description of the liquid-solid transition, within the density-functional theory of non-uniform fluids, are put into a critical perspective by comparing the different methods proposed and the results obtained for the freezing of hardcore systems.
It is shown that an orbital-polarization correction to a spin-polarized band-structure calculation leads to an insulating gap for CoO, in sharp contrast to a standard band calculation. Orbital-polarization instabilities, though, are not found for FeO and ${\mathrm{La}}_{2}$${\mathrm{CuO}}_{4}$.
Ceramics are a distinct class ofmaterials whose properties range from extreme hardness to unique electrical behavior. New methods of creating thin films of complex oxides and electronic ceramics allow the integration of these properties with semiconductor technology and raise the possibility of a new range of electron…
Ultrasound has become an important synthetic tool in liquid-solid chemical reactions, but the origins of the observed enhancements remained unknown. The effects of high-intensity ultrasound on solid-liquid slurries were examined. Turbulent flow and shock waves produced by acoustic cavitation were found to drive metal…
Abstract Electron‐donating substituents of N‐(arylamine) phthalimides and succinimides promote antioxidative efficiency of these compounds in thermooxidation of polypropylene (190°C, oxygen), while electron‐withdrawing substituents contribute to a reduced volatilization of the polymer. 2,6‐Ditert.butyl‐4‐methylphenol…
Abstract When exposed to the weather (moderate climate, Darmstadt), polymethylmethacrylate (PMMA) experiences weight changes, depending on the seasonal humidity, but no material loss. Polycarbonate (PC) on the other hand, and to a lesser degree PC with a “weather skin”, shows marked weight changes when exposed to arti…
Summary The mere presence of H2S in a wet oil or gas system may cause either weightloss corrosion or sulfide stress cracking (SSC) of carbon and low-alloy steels.in addition, H2S may enhance chloride stress corrosion cracking (SCC) ofstainless steels and other higher alloys. The likelihood that these phenomenawill occ…
Shell losses in shell-form power transformers are investigated, using a 2-D finite-element method into which a correction factor is introduced to take account of the third dimension. Lines of flux are plotted and a comparison is made with alternative calculation results. A 13.333-MVA shell-form power transformer now u…
Abstract Polarized, low frequency (5–400 cm −1 ) Raman scattering spectra in single crystals of sodium acid phthalate (NaAP) were measured at 295 and 115 K. Similarly, infrared scattering measurements were performed by FTIR reflection and transmission techniques at room temperature. Symmetry assignments and band descr…
Abstract The photophysics and photochemistry of N ‐amino‐substituted pyridinium salts were investigated. Electron transfer from the amino group to the pyridinium ring takes place in the singlet excited state. The fluorescence quenching and photoreactivity of these compounds is conditioned by this process. Irradiation…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTOxymitrone et 9α-O-Méthyl-oxymitrone, Nouveaux Dérivés Hexahydroxantheniques Isolés de Oxymitra kingiiP. Richomme, S. Sinbandhit, B. David, A. Hamid A. Hadi, and J. BrunetonCite this: J. Nat. Prod. 1990, 53, 2, 294–297Publication Date (Print):March 1, 1990Publication History…
During the period from 1955 to 1978, the insulation system of choice for motor windings in Japan was predominantly of the polyester type. Since there are still a number of polyester-insulated motors in the field, there is a demand for a reliable means of evaluating the residual life of these units, the ultimate goal b…