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951.
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954.
Finite speed of propagation and local boundary conditions for wave equations with point interactions
Pavel Kurasov Andrea Posilicano 《Proceedings of the American Mathematical Society》2005,133(10):3071-3078
We show that the boundary conditions entering in the definition of the self-adjoint operator describing the Laplacian plus a finite number of point interactions are local if and only if the corresponding wave equation has finite speed of propagation.
955.
John F. Nagle 《Journal of statistical physics》1985,38(3-4):531-540
It has been suggested that some lattice models of polymers, especially ones that incorporate more realistic excluded volume interactions extending to further neighbors, may be subject to gridlock. A model is defined to have the property of gridlock if it cannot melt at any temperature unless a density decrease is allowed. Classical theories of polymer melting are incompatible with the property of gridlock. This paper proves rigorously that a two-dimensional square-lattice model of polymer chains that have nearest-neighbor excluded volume interactions (called the X1S model) has the gridlock property. The proof uses elementary concepts from graph theory. Also, different interpretations of the X1S model are given in terms of real polymers. This leads to a discussion of a number of different classes of melting depending upon whether the intramolecular rotameric energies and the attractive intermolecular energies are antagonistic to or supportive of the melting transition. 相似文献
956.
Rabindra N. Roy James J. Gibbons Jonathan K. Trower Gregory A. Lee 《Journal of solution chemistry》1980,9(7):535-551
Activity coefficients of hydrochloric acid in mixed solutions of manganous chloride at twelve ionic strengths, from 0.1 to 5.0 mole-kg–1, were obtained from emf measurements of cells without liquid junction at five temperatures from 5 to 45°C. The data were interpreted in terms of the simple and convenient Pitzer treatment. Activity coefficients for manganous chloride in the mixtures were also derived using Pitzer's equations. Hydrochloric acid follows Harned's rule fromI=0.1 to 3.0 mole-kg–1, as concluded by Downes, whereas quadratic terms are warranted fromI=3.5 to 5.0 mole-kg–1. Contrary to Downes' conclusion, Harned's rule clearly does not hold true for manganous chloride at most ionic strengths. 相似文献
957.
The thermal motion of a long-chain molecule dispersed in a solvent is examined in terms of the velocity autocorrelation, in a reference frame attached to a subunit of the chain. 相似文献
958.
J. P. Stark 《Journal of statistical physics》1971,3(4):395-399
The classical canonical partition function for a one-dimensional, two-component system is examined for the case of nearest-neighbor interactions. The quasi-chemical model of solid solutions is found to be a natural consequence of the definition of the partition function when one replaces the normal configurational energy with a configurational free energy. Consequently, the quasi-chemical theory may be viewed as a consequence of the definition of the partition function and not as merely a physically pleasing model. 相似文献
959.
James L. Monroe 《Journal of statistical physics》1992,67(5-6):1185-1200
We continue an earlier study of multisite interaction Ising spin models on Husimi trees. In particular, attention is given to systems with both a nearestneighbor pair interaction and three-site interactions. We use our calculations of the phase diagrams of the systems on Husimi trees as approximations of systems with the same interactions but on a regular lattice, e.g., the triangle lattice. Specific models where exact results are available are used as test cases. All of the work involves computation of quantities, such as the magnetization, by iterative processes. Hence we are dealing with a discrete map and for certain values of the interaction strengths we obtain for the magnetization diagram results involving period doubling, chaos, period-three windows, etc., all phenomena of recent interest in connection with dynamical systems and now associated with certain Ising spin systems. 相似文献
960.
Quantum chromodynamics corrections to orderα
s (the running coupling constant), using the quark-parton approach are calculated for the spin-dependent structure functions
in deep-inelastic polarised electron-nucleon scattering. Consequences of these corrections for the Bjorken sum rule and the
asymmetry in the case of longitudinally polarised (with respect to the beam) nucleons is discussed which could provide possible
tests of quantum chromodynamics. Comparison of our results with the moments of the flavour non-singlet contribution to the
structure functions obtained using operator product expansion is also given.
An erratum to this article is available at . 相似文献