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991.
992.
993.
Thomas Simon 《Journal of statistical physics》2008,131(4):733-747
Consider an inviscid Burgers equation whose initial data is a Lévy α-stable process Z with α>1. We show that when Z has positive jumps, the Hausdorff dimension of the set of Lagrangian regular points associated with the equation is strictly
smaller than 1/α, as soon as α is close to 1. This gives a partially negative answer to a Conjecture of Janicki and Woyczynski (J. Stat. Phys. 86(1–2):277–299,
1997). Along the way, we contradict a recent Conjecture of Z. Shi () about the lower tails of integrated stable processes. 相似文献
994.
Simon J. Holder Geraldine G. Durand Chert‐Tsun Yeoh Elodie Illi Nicholas J. Hardy Tim H. Richardson 《Journal of polymer science. Part A, Polymer chemistry》2008,46(23):7739-7756
A series of ABA amphiphilic triblock copolymers possessing polystyrene (PS) central hydrophobic blocks, one group with “short” PS blocks (DP = 54–86) and one with “long” PS blocks (DP = 183–204) were synthesized by atom transfer radical polymerization. The outer hydrophilic blocks were various lengths of poly(oligoethylene glycol methyl ether) methacrylate, a comb‐like polymer. The critical aggregation concentrations were recorded for certain block copolymer samples and were found to be in the range circa 10−9 mol L−1 for short PS blocks and circa 10−12 mol L−1 for long PS blocks. Dilute aqueous solutions were analyzed by transmission electron microscopy (TEM) and demonstrated that the short PS block copolymers formed spherical micelles and the long PS block copolymers formed predominantly spherical micelles with smaller proportions of cylindrical and Y‐branched cylindrical micelles. Dynamic light scattering analysis results agreed with the TEM observations demonstrating variations in micelle size with PS and POEGMA chain length: the hydrodynamic diameters (DH) of the shorter PS block copolymer micelles increased with increasing POEGMA block lengths while maintaining similar PS micellar core diameters (DC); in contrast the values of DH and DC for the longer PS block copolymer micelles decreased. Surface‐pressure isotherms were recorded for two of the samples and these indicated close packing of a short PS block copolymer at the air–water interface. The aggregate solutions were demonstrated to be stable over a 38‐day period with no change in aggregate size or noticeable precipitation. The cloud point temperatures of certain block copolymer aggregate solutions were measured and found to be in the range 76–93 °C; significantly these were ∼11 °C higher in temperature than those of POEGMA homopolymer samples with similar chain lengths. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 7739–7756, 2008 相似文献
995.
996.
A. Bussman-Holder H. Büttner A. Simon V. Waas 《Zeitschrift für Physik B Condensed Matter》1990,79(3):445-449
The lattice dynamical properties of BaPb1–x
Bi
x
O3 are described within the polarizability model for perovskite oxides, but extended to take into account the valence instability of Bi. In a quantitative investigation it is found that a mode softening to a ferroelectric state is excluded, but a transition to a paired electron state is possible. The transformation of the classical Hamiltonian to its quantum-mechanical equivalent shows the parameter regimes for which pairing of electrons and thus possibly superconductivity occur. 相似文献
997.
F. D. Berg M. Pfeiffer O. Schwalb M. Appenheimer W. Döring M. Franke W. Kühn V. Metag W. Niebur R. Novotny J. Ritman M. Röbig H. Ströher A. Boonstra H. Löhner A. Raschke L. Venema H. W. Wilschut N. Brummund W. Henning S. Hlavac R. Holzmann R. S. Simon 《Zeitschrift für Physik A Hadrons and Nuclei》1990,337(3):351-352
π0 -production probability of (9± 2)· 10? 3 per20Ne+Al reaction has been measured at 350 MeV/u using the Two Arm Photon Spectrometer TAPS. This yield is consistent with an interpolation of published π-production rates in heavy ion collisions. 相似文献
998.
999.
We consider C=A+B where A is selfadjoint with a gap (a,b) in its spectrum and B is (relatively) compact. We prove a general result allowing B of indefinite sign and apply it to obtain a (δV)d/2 bound for perturbations of suitable periodic Schrödinger operators and a (not quite) Lieb–Thirring bound for perturbations of algebro-geometric almost periodic Jacobi matrices. 相似文献
1000.
Konstantis F. Konidaris Giannis S. Papaefstathiou Guillem Aromi Simon J. Teat Evy Manessi-Zoupa Albert Escuer Spyros P. Perlepes 《Polyhedron》2009,28(9-10):1646-1651
The synthesis, single-crystal X-ray structure and magnetic properties of [Cu3L2Cl2(DMF)4]n (1), where L2? is the 2,3-dioxyquinoxalinate(-2) ligand, are reported. The complex was prepared by the reaction of CuCl2 and 1,4-dihydro-2,3-quinoxalinedione (H2L′) under basic conditions using either solvothermal or normal laboratory techniques. Compound 1 is a 3D coordination polymer with an (82.10)-a, lig (LiGe) topology, containing the ligand in a novel 3.1111 (Harris notation) coordination mode. Variable-temperature and variable-field magnetic studies reveal that the ligand L2? propagates weak antiferromagnetic exchange interactions through its “quinoxaline” part. IR data are discussed in terms of the structural features of 1 and the coordination mode of L2?. 相似文献