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991.
992.
For scalar diffusion models with unknown drift function asymptotic equivalence in the sense of Le Cam's deficiency between
statistical experiments is considered under long-time asymptotics. A local asymptotic equivalence result is established with
an accompanying sequence of simple Gaussian shift experiments. Corresponding globally asymptotically equivalent experiments
are obtained as compound experiments. The results are extended in several directions including time discretisation. An explicit
transformation of decision functions from the Gaussian to the diffusion experiment is constructed.
The authors acknowledge the financial support provided through the European Community's Human Potential Programme under contract
HPRN-CT-2000-00100, DYNSTOCH 相似文献
993.
994.
Measurement of evaporation residue cross-sections of the reaction 30Si + 238U at subbarrier energies
K. Nishio S. Hofmann F. P. Heßberger D. Ackermann S. Antalic V. F. Comas Z. Gan S. Heinz J. A. Heredia H. Ikezoe J. Khuyagbaatar B. Kindler I. Kojouharov P. Kuusiniemi B. Lommel R. Mann M. Mazzocco S. Mitsuoka Y. Nagame T. Ohtsuki A. G. Popeko S. Saro H. J. Schött B. Sulignano A. Svirikhin K. Tsukada K. Tsuruta A. V. Yeremin 《The European Physical Journal A - Hadrons and Nuclei》2006,29(3):281-287
The reaction 30Si + 238U → 268Sg* was studied at beam energies close to the Coulomb barrier. At a center-of-mass energy of E
c.m. = 144.0MeV for reactions at half thickness of the target we measured three decay chains of 263Sg produced by evaporation of five neutrons. The cross-section was ( 67+67
-37) pb. At E
c.m. = 133.0MeV we measured three spontaneously fissioning nuclei which we assigned to the isotope 264Sg. The production cross-section was ( 10+10
-6) pb and a half-life of ( 120+126
-44) ms was determined. This half-life is a factor of twenty shorter than theoretical predictions. At E
c.m. = 128.0MeV an upper cross-section limit of 15pb was measured. The cross-section data reveal a strong influence of the orientation
of the deformed target nucleus on the production yield. Compared to excitation functions measured for the lighter system 16O + 238U → 254Fm*, a reduction of the fusion probability was observed at low beam energies indicating increasing competition from quasifission
processes. 相似文献
995.
A system of independent electrons in a random potential on the surface of a finite cylinder is considered in the presence of a perpendicular magnetic field. It is shown that the spectral stability condition which essentially asserts that the range of variation of the electrostatic energy in an external electric field is independent of disorder, and which is sufficient to prove the integer quantization of the Hall conductivity is also sufficient to prove the exact compensation of current loss brought about by bound states by current gain in extended states for completely filled Landau bands. Furthermore, the spectral stability condition is shown to be both sufficient and necessary to prove Levinson's theorem which was used by some authors to demonstrate compensation. 相似文献
996.
Ohne Zusammenfassung 相似文献
997.
The quaternionic calculus is a powerful tool for treating the Navier–Stokes equations very elegantly and in a compact form, through the evaluation of two types of integral operators: the Teodorescu operator and the quaternionic Bergman projector. While the integral kernel of the Teodorescu transform is universal for all domains, the kernel function of the Bergman projector, called the Bergman kernel, depends on the geometry of the domain. In this paper, we use special variants of quaternionic‐holomorphic multiperiodic functions in order to obtain explicit formulas for unbounded three‐dimensional parallel plate channels, rectangular block domains and regular triangular channels. Copyright © 2007 John Wiley & Sons, Ltd. 相似文献
998.
Tomás Pérez-Ruiz Carmen Martinez-Lozano Virginia Tomás Encarnación Yagüe 《Mikrochimica acta》1989,98(1-3):129-137
A study of the photochemical reaction of the methylviologen (MV2+)-EDTA-Acridine Yellow system in the presence of nitroprusside (NP) is presented. The rate of photoreduction of methylviologen to the cation radical MV+ is dramatically retarded by small amounts of NP, which has an inhibitory effect on the excited state of Acridine Yellow, which is the activator of the process. Optimal conditions for the determination of NP in the range of concentrations between 2 × 10–6 and 3 × 10–5
M are described. The method proposed has been applied with excellent results to the determination of NP in pharmaceuticals and human serum, after protein elimination by perchloric acid. 相似文献
999.
Combinatorics & Topology of Stratifications of The Space of Monic Polynomials With Real Coefficients
We study the stratification of the space of monic polynomials with real coefficients according to the number and multiplicities of real zeros. In the first part, for each of these strata we provide a purely combinatorial chain complex calculating (co)homology of its one-point compactification and describe the homotopy type by order complexes of a class of posets of compositions. In the second part, we determine the homotopy type of the one-point compactification of the space of monic polynomials of fixed degree which have only real roots (i.e., hyperbolic polynomials) and at least one root is of multiplicity k. More generally, we describe the homotopy type of the one-point compactification of strata in the boundary of the set of hyperbolic polynomials, that are defined via certain restrictions on root multiplicities, by order complexes of posets of compositions. In general, the methods are combinatorial and the topological problems are mostly reduced to the study of partially ordered sets. 相似文献
1000.