Materials Literature
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Abstract The accomplishments of Borden Award Winner John K. Gillham and his colleagues using Torsional Braid Analysis (TBA) and Differential Scanning Calorimetry (DSC) to investigate the T g and T > T g or T u regions of anionic and thermal poly styrenes (PS) are evaluated and related to work on PS and other polyme…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTPhthalocyanine thin films as semiconductor electrodesFu-Ren Fan and Larry R. FaulknerCite this: J. Am. Chem. Soc. 1979, 101, 17, 4779–4787Publication Date (Print):August 1, 1979Publication History Published online1 May 2002Published inissue 1 August 1979https://pubs.acs.org/…
The electronic band structure of zinc-blende CuCl is computed using a self-consistent, first-principles, all-electron approach. The calculated energy levels agree with photoemission results and support a minimum-direct-gap interpretation of the optical data. Contrary to the indirect model proposed by Rusakov and used…
High-resolution c-axis images of the biopyribole minerals anthophyllite [(Mg,Fe)' Si8Orr(OH)rl, jimthompsonite [(Mg,Fe),oSi,rOrr(OH)o], and chesterite [(Mg'Fe),rSiro O'4(OH)61 have been produced in the transmission electron microscope. Interpretation of the images has been confirmed by dynamical electron di-ffraction…
The dislocation theory of the liquid state is refined by an accurate assessment of the interaction energy between dislocations. This shows a screening phenomenon which gives a first-order transition rather than the second-order transition of simpler theories. Within this framework, a theory of glass is constructed in…
Abstract The calcination of synthetic hydrotalcites of different compositions gave aluminium magnesium double oxides with strong basic sites and a high catalytic activity towards the polymerization of β-propiolactone. The strong basic sites were determined and compared with the apparent polymerization rates, suggestin…
Abstract— Ab initio configuration interaction wavefunctions and energies are reported for the ground state and many low‐lying excited singlet and triplet states of ethyl pheophorbide a (Et‐Pheo a ) and ethyl chlorophyllide a (Et‐Chl a), and are employed in an analysis of the electronic absorption spectra of these syst…
An indexed powder pattern is reported for Mg2Na4O10Si3. The unit cell is orthorhombic, a = 10.584 (7), b = 14.328 (7), c = 10.457 (7) Å. Transition to a cubic phase, a = 7.440 Å, occurs at 918 K. A Na-deficient tetragonal phase was also observed.
This paper reports some irradiation effects and recovery behavior of neutron irradiated boron carbide pellets that were used as control rod elements in the Enrico Fermi Fast Breeder Reactor. Measurements were carried out on changes in lattice parameters, thermal expansion, helium release, elastic moduli and microstruc…
BaSb 2 Se 4 crystallizes in the monoclinic system, space group P2 1 /n, with a = 923.7 ± 0.8 pm, b = 2076 ± 3 pm, c = 855.1 ± 0.8 pm, β = 91.2 ± 0.1°. One half of the Sb atoms form ψ-tetrahedra with three neighbouring selenium atoms, the other half forms ψ-trigonal bipyramids with four selenium atoms. These polyhedra…
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…