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Abstract Fourier transform infrared spectroscopy (FT‐IR) has been applied to the study of the molecular mechanisms of transitions of atactic polystyrene above T g . Intensity measurements of vibrational modes as a function of temperature revealed two transitions above T g , which are designated as T u and T ′ u . T ′…
The hardening of iron-chromium alloys containing more than 13 wt-%Cr in the temperature range 550–800°C is well known and is ascribed to the formation of σ-FeCr. Severe embrittlement at lower temperatures, commonly referred to as ‘475°C embrittlement’, is less well understood and has been variously ascribed to σ-phase…
Abstract The reflection spectra of Bi 12 GeO 20 and Bi 12 SiO 20 single crystals are studied in the spectral region 50 to 1000 cm −1 at 90 and 300K. Both the single crystals are found to exhibit several reflection bands which are ascribed to the interaction of electromagnetic radiation with normal modes of F‐symmetry…
Abstract Hydrothermal reactions in the system sepiolite/H 2 O have been examined between 149° and 316°C. Approximately 10–20% of the starting sepiolite was converted to a smectite (stevensite) at 204°C within 24 hr. Similar results were obtained when CaCl 2 , NaOH, Ca(OH) 2 , or Mg(OH) 2 was added to the system. In th…
Abstract In the existing literature various values are given for the intrinsic birefringence of the crystalline and the amorphous phases in poly(ethylene terephthalate) (PET). These values have either been calculated theoretically or obtained from experimental data on the basis of certain models. In this investigation…
The structure of an alkali cation-deflcient, vanadium tourmaline has been refined (R: 0.Ml for 2727 rntensity data) in order to evaluate the effects of tourmaline composition on structural distortion. V-tourmaline, (Nao*Ca.r"Mgo.,rIGor)(Mg,rrVlj"Ct'olrFe2o:r8) (Al5s6 V3*38Tit*o6XSi563Abj7XB2…
When energetic particles impinge on a solid, atoms are displaced from their lattice positions. Single or clustered vacant atomic sites are produced and the displaced atoms come to rest in interstitial configurations. The bombarding particles may also induce nuclear transmutations. The initial disturbance of the materi…
Ni pigmentation of anodic Al2O3 is obtained by electrolytic coloration. Durable coatings with good spectral selectivity (a/e≃8) are produced. Scanning electron microscopy, Auger depth profiling, and atomic absorption analysis lead to the formulation of a detailed structural model, its most essential feature being a th…
The complex rheological behavior of the sy.in under biaxial deformations is exhibited in terms of its experimental stress-strain relationships under constant strain level. The stress-strain relationships are anisotropic, nonlinear, strain rate depend
The coordination of Al3 * in glasses of jadeite composition, synthesized at 1450 " and 1550"C and over the pressure range 0.fi)l-40 kbar, has been determined using laser Raman spectroscopy. The Raman spectrum of glass ofjadeite composition at I atm resembles that of SiO2 glass, except that the Si-O s…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTMetal clusters. 21. Synthesis of rhodium phosphite clustersAndrew J. Sivak and E. L. MuettertiesCite this: J. Am. Chem. Soc. 1979, 101, 17, 4878–4887Publication Date (Print):August 1, 1979Publication History Published online1 May 2002Published inissue 1 August 1979https://do…
The thermal expansion and the forced volume magnetostriction have been measured for the Invar type Fe-Pt alloys. Derived values of the spontaneous volume magnetostriction are large and the same order of magnitude as those for the Fe-Ni Invar alloys. Their dependence on concentration and chemical ordering can be explai…
The pressure dependences of the dielectric properties and phase transitions of squaric acid, H2C4O4, and its deuterated analog, D2C4O4, were investigated. The transition temperatures at 1 bar are 375.5±1.0 K and 527.5±2.0 K, respectively, and decrease with pressure at initial rates of 105.6±2.0 K/GPa and 102.5±2.0K/GP…
Lutetium diphthalocyanine can be electrolyzed reversibly in dimethylformamide to give four different colored solutions: violet, blue, green, and yellow‐red. Two of these solutions, the violet and the green, also exhibit electron paramagnetic resonance (EPR) signals indicative of organic‐free radicals. The blue and the…
The corrosion of 90:10 Cu:Ni and 70:30 Cu:Ni alloys in sulfide polluted flowing sea water has been studied as a function of sulfide concentration. The experimental techniques used include small amplitude cyclic voltammetry, AC impedance measurements, large amplitude cyclic voltammetry, and extensive surface examinatio…
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Abstract In the frame of a fluctuation approach to the glass transition, it is shown from a scaling argument that the product δ In v δ T (≈ 15 K for polymers) is invariant with respect to the temperature or frequency dependence of the glass transition in homogeneous amorphous substances. With the aid of a differential…
Homogeneous preparations of pesticin, a bacteriocin produced by Yersinia pestis, neither significantly inhibited net synthesis of deoxyribonucleic acid, ribonucleic acid, or protein in Escherichia coli phi nor caused detectable degradation of deoxyribonucleic acid in vivo. Accordingly, its mode of action does not rese…
Many researchers have suggested that the space charge field of the primary electron avalanche should not be neglected in calculating the corona onset voltage based on the streamer criterion. Some researchers consider only the space charge field of the positive ions created during the avalanche growth, while others con…
Transaminase B (branched-chain amino acid aminotransferase, EC 2.6.1.42), the ilvE gene product, was purified to apparent homogeneity from an Escherichia coli K-12 strain which carries the ilvE gene both on the host chromosome and on a plasmid. The oligomeric structure of the enzyme, as determined by analytical ultrac…