Materials Literature
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Abstract The glass transition temperature (T g ) of an amorphous polymer is the temperature at which motion occurs in the major segments of the backbone molecular chain of the polymer. However, the effect of water on the T g of a hydrophobic polymer has generally not been recognized. Almost all fibers are only partial…
Pig heart citrate synthase was subjected to limited proteolytic attack by subtilisin, chymotrypsin, and trypsin in the presence of palmitoyl-CoA. Initial proteolysis by all three proteolytic enzymes resulted in cleavage of the monomeric subunit (Mr 45 000 +/- 3000) into a large (Mr 35 000-38 500) and a small (Mr 9000…
Abstract A critical pore size is defined as the largest pore that can carry 100% non-freezing water. Pores of size larger than critical pore size will have freezing and non-freezing water. The critical pore size for pulp fibers is estimated as 40 Å. Since more than 98% of the surface area may be in pores smaller than…
High-resolution x-ray scattering studies show a new charge-density wave (CDW) structure on warming through the commensurate-incommensurate transition in $2H$-Ta${\mathrm{Se}}_{2}$ at 93 K. In contrast to the fully incommensurate CDW structure seen on cooling, hexagonal symmetry is broken in the new phase and the tripl…
Polystyrene spheres (2450 \AA{} in diameter) are trapped in a surface energy well at water/air interface. Because of asymmetry of charge distribution, electrical dipoles are associated with each interfacial particle. The dipole-dipole repulsive interactions organize the polystyrene spheres into a two-dimensional trian…
The static configurations of domain boundaries are studied in the α, β, and γ phases of ferroelastic lead orthovanadate. The domain configurations can consistently be understood on the basis of strain energy minimization considerations. The boundary orientations in the β-phase are consistent with the theoretical predi…
In zero-gap ${\mathrm{Hg}}_{1\ensuremath{-}x}{\mathrm{Mn}}_{x}$ Te alloys, the existence of spin-orbit coupling in the intermediate states leads to anisotropic indirect exchange interactions between localized spins. These effects are evaluated and are shown to reduce the Curie-Weiss temperature previously calculated.
A classical theory of the static strains and lattice dynamics for solids possessing incommensurate structures is developed using a spatial Fourier representation of the static strains and a space-time Fourier representation of the dynamical modes. Although the theory is presented for one-dimensional systems, the gener…
Using a refinement of a capillary technique described earlier precise PVT data on D2O between 0.1 and 140 MPa and down to −30 °C have been obtained, and the pressure dependence of the volumetric behavior in the vicinity of the well-known density maximum has been examined. The ’’sharpness’’ of the density maximum, defi…
A model for Raman scattering from molecules chemisorbed on surfaces is proposed. We suggest that part of the enhancement is due to modulation of the metal-surface reflectivity by the motion of the atom binding the molecule to the surface. The parameters entering the model are easily estimated from a jellium model of t…
The order parameter model is generalized to describe systems whose equilibrium states depend on other intensive variables, e.g., electric field E, in addition to temperature T and pressure P. The set of order parameters required to specify the state of a liquid or glass is shown to form an abstract Euclidean vector sp…
Comparisons of theoretical calculations and experimental measurements of echelle grating-efficiencies are given for R2 echelles used in three possible configurations: alpha > beta;alpha < beta and the quasi-Littrow mode. The throughput-resolution products for these various cases are also compared.
Dynamic deformation of solid materials is described in terms of nonuniform material motion and simultaneous thermoelastic strain and plastic flow. For deformations of arbitrary form and magnitude in an initially isotropic solid, an approximate expression for the entropy production is given, and the interrelations amon…
In an effort to examine further the suggestion that anomalies in the properties of supercooled water reflect the approach to a thermodynamic singularity in the vicinity of −45 °C, an attempt has been made to separate the total heat capacity of water into ’’anomalous’’ and ’’normal’’ components. The basis for such a se…
Using photon-energy-dependent photoemission techniques with a diamond (111)-(1 \ifmmode\times\else\texttimes\fi{} 1) crystal surface, we have determined critical points of energy bands at $\ensuremath{\Gamma}$ and $L$ (${\ensuremath{\Gamma}}_{1}=\ensuremath{-}21$ eV, ${L}_{1}=\ensuremath{-}12.8$ eV, ${L}_{2}^{\ensurem…
An iterative, self-consistent procedure for the Kramers-Kronig analysis of data from reflectance, ellipsometric, transmission, and electron-energy-loss measurements is presented. This procedure has been developed for practical dispersion analysis since experimentally no single optical function can be readily measured…
An examination is made of the influence of the conditions of sliding on the 'dusting' wear of graphitic carbon sliding against non-graphitic carbon. Specific wear rates are essentially independent of load, speed and contact temperature over a wide range, but begin to decrease at speeds above about 10 m s -1 . At these…
The simultaneous translational and rotational brownian motions of an assembly of interacting cylindrically symmetric polar molecules are assumed to obey a generalized N-particle Smoluchowski-Einstein-Debye equation. Rigorous relations are derived between the self-rotational diffusion coefficient and the initial slopes…
The binding, or association, constants of NADP+ NADPH, and a series of structural analogues to dihydrofolate reductase from Lactobacillus casei MTX/R have been determined fluorometrically. Modification of the adenine or nicotinamide rings has little effect on the binding of the oxidized coenzyme, but the thionicotinam…
Anomalous, low-frequency Raman scattering from localized acoustic vibrations of roughness features on a metal surface are observed. The observed mode frequency shifts with excitation frequency and with the index of refraction of the surrounding medium. The shifts arise from resonant laser excitation of localized dipol…