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81.
Constantin JG Fris AR Appignanesi G Carignano M Szleifer I Corti H 《The European physical journal. E, Soft matter》2011,34(11):126
The structure of water clusters (H2O)n (n = 40 -200) and bulk water were examined by molecular dynamics simulations using the TIP4P-ice water model. The analysis of
the low-temperature structures in terms of the local structure index (LSI) showed a bimodal distribution. This finding supports
the two-state picture derived from the analysis of the inherent dynamics of bulk SPC/E water. The water molecules at the outer
interface of the coldest clusters are more structured than those in the inner core. The geometrical constraint of the interface
forces the surface molecules to lose one neighbor and adopt a local angular distribution of hydrogen bonds resembling that
found in the basal plane of ice Ih. 相似文献
82.
The Lorentz-violating isotropic modified Maxwell theory minimally coupled to standard Dirac theory is characterized by a single real dimensionless parameter which is taken to vanish for the case of the standard (Lorentz-invariant) theory. A finite domain of positive and negative values of this Lorentz-violating parameter is determined, in which microcausality and unitarity hold. The main focus of this article is on isotropic modified Maxwell theory, but similar results for an anisotropic nonbirefringent case are presented in Appendix A. 相似文献
83.
84.
In this note we are concerned with numerical solutions to Dirichlet problem $$[\phi(u')]' =f(x) \quad \mbox{in} [\alpha, \beta]; \quad u(\alpha)=A, \; u(\beta)=B, $$ where \(\phi :(-\eta , \eta ) \to \mathbb {R}\) \((\eta <+ \infty )\) is an increasing diffeomorphism with \(\phi '(y)\geq d >0\) for all \(y\in (-\eta , \eta )\) . The obtained algorithm combines the shooting method with Euler’s method and it is convergent whenever the problem is solvable. We provide numerical experiments confirming the theoretical aspects. 相似文献
85.
In constraining iterative processes, the algorithmic operator of the iterative process is pre-multiplied by a constraining operator at each iterative step. This enables the constrained algorithm, besides solving the original problem, also to find a solution that incorporates some prior knowledge about the solution. This approach has been useful in image restoration and other image processing situations when a single constraining operator was used. In the field of image reconstruction from projections a priori information about the original image, such as smoothness or that it belongs to a certain closed convex set, may be used to improve the reconstruction quality. We study here constraining of iterative processes by a family of operators rather than by a single operator. 相似文献
86.
The electrochemical stability of TiO2 nanoarchitecture fabricated in fluoride electrolyte presented in this paper is related to 2D and 3D geometries that present a shift from nanopores toward nanotubes. The fabrication conditions involve a 60 V applied voltage for 2 hours of anodizing in order to create the ordered structures, in a mixture of low‐water glycerol electrolyte and fluoride. With the use of different ultrasonication times, a variety of nanotubes/nanopores were observed. The surface interfacial aspects were investigated mainly by surface microscopy and hydrophilic/hydrophobic balance for the grown structures ultrasonicated at various periods of time. The electrochemical behavior of the nanotube‐structured surface was performed by potentiodynamic evaluation and electrochemical impedance spectroscopy in a simulated body fluid solution. As a most important result, all surface analysis and electrochemical data interpretation permitted the proposition of a model for elaboration of different nanostructures from nanopores to nanotubes. These different surface nanoarchitectures were obtained as a result of ultrasonication at various periods of time. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
87.
88.
89.
Let V be an indefinite quadratic space over a number field F and U be a nondegenerate subspace of V. Suppose that M is a lattice on V, and that N is a lattice on U which is represented by M locally everywhere. The main result of this paper is a necessary and sufficient condition for which there exists a representation of N by M that approximates a given family of local representations. This is applied to determine when the variety of representations of U by V has strong approximation with respect to a finite set of primes of F that contains all the archimedean primes. 相似文献
90.
Constantin Teleman 《Inventiones Mathematicae》1998,134(1):1-57
Let G be a semi-simple group and M the moduli stack of G-bundles over a smooth, complex, projective curve. Using representation-theoretic methods, I prove the pure-dimensionality
of sheaf cohomology for certain “evaluation vector bundles” over M, twisted by powers of the fundamental line bundle. This result is used to prove a Borel-Weil-Bott theorem, conjectured by
G. Segal, for certain generalized flag varieties of loop groups. Along the way, the homotopy type of the group of algebraic
maps from an affine curve to G, and the homotopy type, the Hodge theory and the Picard group of M are described. One auxiliary result, in Appendix A, is the Alexander cohomology theorem conjectured in [Gro2]. A self-contained
account of the “uniformization theorem” of [LS] for the stack M is given, including a proof of a key result of Drinfeld and Simpson (in characteristic 0). A basic survey of the simplicial
theory of stacks is outlined in Appendix B.
Oblatum 17-XII-1996 & 26 VI-1997 相似文献