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261.
A. Vermogen E. Picard M. L. Milan K. Masenelli‐Varlot J. Duchet G. Vigier E. Espuche J. F. Gérard 《Journal of Polymer Science.Polymer Physics》2008,46(18):1966-1975
Semi‐crystalline polymer‐clay nanocomposite properties are often considered only by their clay dispersion state. The purpose of this work is to highlight texture effects on semi crystalline polymer‐clay properties. Maleic anhydride‐grafted polyethylene nanocomposites with two different processing techniques (Blown Extrusion and Compression) were studied. The processing was shown to induce different crystalline lamellae orientation in the films but with no significant changes in the crystalline lamellae long period, degree of crystallinity, clay particle orientation morphology and dispersion. The impact of these specific textures on the nanocomposites barrier and tensile properties were reported. © 2008 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 46: 1966–1975, 2008 相似文献
262.
Milan Randić 《Theoretical chemistry accounts》1983,62(6):485-498
The characteristic polynomial of a structure (molecule or a graph) is usually expressed as a function ofx. Here we explore an alternative representation of characteristic polynomials expressed in terms ofL n , the characteristic polynomials of linear chains havingn atoms. While the new forms of the characteristic polynomials are mathematically equivalent to the old forms, they appear to reflect selected structural similarities among homologous molecules better. Besides arriving at general expressions for the form of the characteristic polynomials for numerous families of compounds previously unavailable, the approach is of some interest for the old problem of graph isomorphism and graph recognition in cases of structures which can be associated with a homologous series. 相似文献
263.
The collapse in a quantum-mechanical measurement is treated as a physical process, described by a superoperator mapping states into states and depending only on the measured observable. The assumption that the states with a sharp value of the measured observable remains unchanged yields the Lüders-Von Neuman formula. 相似文献
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266.
Distant correlations are investigated within the framework of quantum mechanics. They are inherent to any physical situation in which two separated quantal systems are described by one composite state vector. Owing to correlations of this kind one can perform a measurement on one of the systems, thereby measuring a certain observable on the other (distant) system without interacting with it. Necessary and sufficient conditions are given for such a distant measurement to take place. It is found which are the observables that can be measured distantly, and which are the states of the distant system obtainable in this way. Solution of these problems is achieved by replacing the composite state vector by two entities equivalent to it: the reduced statistical operator of the system which is directly measured and a correlation operator. The latter gives a connection between states, observables, and probabilities of the two systems. Experimental evidence for distant measurement is discussed. 相似文献
267.
I. David Reingold Anna M. Butterfield Robert S. Walters Jr. Susan Scheuring Milan Gembický Peter Baran 《Tetrahedron letters》2005,46(22):3835-3837
Perhydrophenanthrene-1,5,10-trione (6) was isolated from the reaction of methyl 3-(carboxymethyl)cyclohexanone and cyclohexenone in a tandem Michael-Claisen reaction. NMR and X-ray analysis confirmed the structure of the product. 相似文献
268.
The anisotropic bidomain model for the propagation of electrical activation in the human myocardium H consists of coupled elliptic-parabolic partial differential equations for the transmembrane potential Vm, intracellular potential phi(i), and extracellular potential phi(e) in H, together with quasi-static equations for the potential distribution phiB in the surrounding (passive) isotropic extracardiac regions B. Four local parameters sigma((i,e) (l,t)) specify the conductivities in the longitudinal (l) and transverse (t) directions with respect to cardiac muscle fibers. Continuous current flow is required at the interface S(H) between H and B. We derive analytic formulas for Vm, phi(e), phi(i), and phiB for plane wave propagation in a uniformly anisotropic slab surmounted by a homogeneous region of conductivity sigmaB. No assumptions are required regarding the anisotropy ratios of the conductivity coefficients. The properties of these solutions are examined with a view to providing insight into the effect of the passive region B on the propagation of Vm and phi(e) in H. We show that for a suitably chosen boundary condition, the problem can be reduced to solving the bidomain equations in H alone. 相似文献
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270.
Milan P. Locher 《Zeitschrift für Angewandte Mathematik und Physik (ZAMP)》1963,14(4):368-372
Zusammenfassung Die KoeffizientenC
r
n
in der Produktdichtenmethode (vgl. [3]) werden unmittelbar aus den Postulaten für die Verteilung kombinatorisch abgeleitet. Das Resultat wird in einen vonStevens gegebenen Ausdruck übergeführt. 相似文献