Materials Literature
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Abstract A brief overview of the important issues governing the behavior of polymer blends is presented. Thermodynamic issues which determine the phase behavior of blends are reviewed and qualitatively related to physical interactions between blend components. The influence of melt processing conditions on the resulti…
n-Nonadecane shows a phase transition from orthorhombic to so called α phase near 22.8 °C and melts at 32 °C. Temperature dependence studies of infrared and Raman spectra of n-nonadecane and of selectively deuterated nonadecanes (2D2 and 10D2) allow one to obtain a detailed description of the structural changes which…
An overview is given of the nonequilibrium behavior of polymeric glasses. While the emphasis is to display the significant effects of the nonequilibrium behavior on observable properties, some general basics of the glass transition behavior and nonequilibrium behavior are also presented. Both molecular as well as phen…
A neutron structure analysis at 2.2-A resolution has been performed on bovine trypsin covalently inhibited by a transition-state analogue, the monoisopropylphosphoryl (MIP) group. The unique ability of neutron diffraction to locate hydrogen atoms experimentally has allowed the determination of the protonation states o…
The possibility of defining structural defects in amorphous solids in terms of parameters such as atomic-level internal stresses and local symmetry coefficients was proposed in a previous paper (Egami, Maeda and Vitek 1980). Using a model amorphous structure generated by a computer, these parameters are statistically…
We have developed an infinite dilution extrapolation procedure for determining the molecular second order optical susceptibility β using dc induced second harmonic generation. We show how the effects of solute–solute and solvent–solvent interactions are minimized by this procedure, and how several local field models u…
The oxygen vacancy concentration of BaTiO 3 doped with acceptors (Cr to Ni) is determined gravimetrically as a function of the O 2 partial pressure during and after annealing at 700° to 1300°C. The oxygen vacancy concentration of these materials is larger than that of undoped and donor‐doped BaTiO 3 . The oxygen vacan…
When an electric field is applied to a dielectric material under adiabatic conditions there is a resultant change in temperature, a phenomenon known as the electrocaloric effect. Compositions in the Pb(Zr,Sn,Ti)O3 system (PZST) have several phases of nearly equal free energy, allowing antiferroelectric (AFE) to ferroe…
An approximate integral-equation approach is used to model the growth and collapse of a vapour cavity in close proximity to an initially plane free surface. By comparison with experiment, it is shown to predict all the salient features of the bubble and freesurface interaction, provided that the complete nonlinear Ber…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTNature of bonding between metallic ions and algal cell wallsRay H. Crist, Karl. Oberholser, Norman. Shank, and . Ming NguyenCite this: Environ. Sci. Technol. 1981, 15, 10, 1212–1217Publication Date (Print):October 1, 1981Publication History Published online1 May 2002Publishe…
The Raman scattering intensity of the 1100 cm−1 polarized band, which appears on the addition of Na2O to SiO2 glass, reaches a maximum at the disilicate composition. The intensity of the polarized band at 950 cm−1 increases sharply as the Na2O concentration increases above 30 mole %. These data were interpreted by nor…
Abstract The effect of excluded volume on the thermodynamic activity of globular macromolecules and macromolecular complexes in solution is studied in the hard‐particle approximation. Activity coefficients are calculated as a function of the fraction of total volume occupied by macromolecules using relations obtained…
Two successive phase transitions, changing the crystal symmetry from rhombohedral to tetragonal, and then to cubic on a heating process, have been investigated in the Pb(Zn1/3Nb2/3)O3-PbTiO3 single crystals with the composition near the morphotropic phase boundary. The existence of the morphotropic phase boundary has…
ABSTRACT The glauconitic facies is widespread on present‐day continental shelves from 50° S to 65° N and at water depths between 50 and 500 m, and is in particularly great abundance on the upper slope and outer shelf between 200 and 300 m. It is also common in many ancient rocks of post‐late Precambrian age. It occurs…
Abstract Quantitative information from electron spectroscopy for chemical analysis requires the use of suitable atomic sensitivity factors. An empirical set has been developed, based upon data from 135 compounds of 62 elements. Data upon which the factors are based are intensity ratios of spectral lines with F1s as a…
The d=3 form of Aharony and Fisher's expression (see Phys. Rev. B vol.8, p.3323, 1973) for the d-dimensional Fourier transform of the dipole-dipole interaction in lattice structures is generalised to the case of more than one atom per unit cell, and extended to provide a simple expression for the matrix elements D AB…
The rate of anneal of stress-induced ordering of isolated substitutional nitrogen impurities in diamond, measured in the temperature range $78 \mathrm{K}<T<200 \mathrm{K}$, shows large deviations from Arrhenius-type behavior. It is concluded that in the temperature range considered, reorientation of the centers…
It is shown that a metal-insulator transition takes place in a Peierls system with half-filled bands at a critical concentration, ${c}_{\mathrm{cr}}$, of excess electrons. At $c<{c}_{\mathrm{cr}}$ the electrons form pinned (chaotic) soliton states; at $c>{c}_{\mathrm{cr}}$ the solitons form an unpinned conductin…
Unusual Structural Feature of Crystalline Phthalic Acid In crystalline phthalic acid the strain resulting from repulsion between the carboxylic groups is only partially relieved by rotating these groups out of the plane of the benzene ring around the (HOO)CC bonds. This is also achieved through a surprisingly large d…
This paper reports on a new phase, denoted X, discovered in Cr100–xAlx alloys in and around the composition range 20 at% ⪅ x ⪅ 25 at%. The electron diffraction patterns of this phase appear to be commensurate with the reciprocal lattice of the disordered b.c.c. α-phase, except in rapidly cooled samples. Dark-field ima…