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排序方式: 共有158条查询结果,搜索用时 31 毫秒
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O. Erriquez S. Natali S. Nuzzo A. Pullia F. Romano D.C. Colley G.T. Jones S. ONeale S.J. Sewell G. Bertrand-Coremans H. Mulkens J. Sacton C. Vander Velde-Wilquet W. Van Doninck V. Brisson P. Petiau A.M. Cooper F.W. Bullock 《Physics letters. [Part B]》1981,102(1):73-78
We have fully analysed all events with a single electron obtained in an exposure of BEBC to the 350 GeV wide-band neutrino beam at CERN. The data agrees well with expectations based on the calculated νe flux and assuming μ?e universality. Using both the rate and the kinematic distributions, improved limits are set on νe → νX, νμ → νe, νμ → ντ mixing. 相似文献
23.
Geoffrey L. Sewell 《Physics letters. A》1980,79(1):23-24
A general, rigorous derivation of the Hawking effect for interacting fields is outlined within the framework of axiomatic Field Theory and Statistical Mechanics. 相似文献
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Baumgärtner F Sewell RJ Eriksson S Llorente-Garcia I Dingjan J Cotter JP Hinds EA 《Physical review letters》2010,105(24):243003
We investigate the use of a Bose-Einstein condensate trapped on an atom chip for making interferometric measurements of small energy differences. We measure and explain the noise in the energy difference of the split condensates, which derives from statistical noise in the number difference. We also consider systematic errors. A leading effect is the variation of the rf magnetic field in the trap with distance from the wires on the chip surface. This can produce energy differences that are comparable with those due to gravity. 相似文献
26.
Boyle TJ Sewell RM Ottley LA Pratt HD Quintana CJ Bunge SD 《Inorganic chemistry》2007,46(5):1825-1835
The reaction of [Ti(mu-ONep)(ONep)3]2 (ONep = OCH2C(CH3)3) with a series of heterocyclic methanol derivatives [tetrahydrofurfuryl alcohol (H-OTHF), thiophene methanol (H-OTPM), or 2-pyridylcarbinol (H-OPy)-collectively termed H-OR*], led to the isolation of a novel family of OR*-substituted titanium alkoxide precursors. Independent of the initial stoichiometry for the H-OTHF reaction, a monosubstituted, dinuclear species was isolated as [(ONep)3Ti(muc-OTHF)]2 (1). For 1, each Ti was octahedrally (Oh) bound by three terminal ONep ligands, one bidentate bridging OTHF ligand (muc-OTHF), and an oxygen from the other muc-OTHF ligand. For the OTPM derivatives, the product was identified as [(ONep)3Ti(mu-OTPM)]2 (2). For this ligand, the soft S atom does not bind to the Ti but the O atom does act as a bridge between the two trigonal bipyramidal bound Ti metal centers. The OPy system yielded (OPy)2Ti(OR)2 independent of the OR and the stoichiometry used [OR = ONep (3), OCHMe2 (4), OCMe3 (5)]. For 3-5, the two OPy ligands chelate to the Oh-bound Ti metal center with two terminal OR ligands. Compounds 1-5 were fully characterized using a variety of analytical techniques. An initial investigation of the proposed chemical stability of the '(OPy)2Ti' moiety of 3-5 to alcoholysis exchange pathways involving (i) alkyl alcohols, (ii) aryl alcohols, (iii) substituted phenols, (iv) H-OR* derivatives, and (v) silanols proved successful through the isolation of a novel family of structurally characterized (OPy)2Ti(OR')2 (7-24) compounds. 相似文献
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Manenkov A.B. Benson T.M. Sewell P.D. Kendall P.C. 《Optical and Quantum Electronics》2000,32(11):1245-1255
A novel scalar (i.e. paraxial) free space radiation mode method is presented for calculating the normal incidence facet reflectivity of the main guided mode of a step-index optical fibre with generally shaped smooth core. Numerical results are presented and discussed for several cases of the Nth order super-elliptical core shape, including the circular, elliptical, rectangular-type and slab limiting cases. 相似文献
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A. L. Ponomarev T. D. Sewell C. J. Durning 《Journal of Polymer Science.Polymer Physics》2000,38(9):1146-1154
We studied by lattice simulation the surface diffusion and relaxation of isolated, self‐avoiding polymers partially adsorbed onto a flat surface. The key parameters describing the system are the number of segments in the chain, N, the adsorption energy of a segment, expressed as a dimensionless surface temperature Ts, and the segmental friction factor on the surface relative to that in the bulk, ζs/ζb. The simulation data indicate Rouse scaling of the surface diffusion coefficient, D∥, and in‐plane relaxation time, τ, versus N for all values of Ts and ζs/ζb studied. A simple application of the Rouse model to a partially adsorbed chain, which ignores fluctuations in adsorbed trains, yields a formula for D∥ with the correct N‐scaling. It can account for the effects of Ts when ζs/ζb is finite (≲10), but it fails when ζs/ζb diverges, predicting no surface diffusion at all, whereas simulations indicate finite surface mobilities facilitated by a caterpillar‐like motion. © 2000 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys 38: 1146–1154, 2000 相似文献
29.
FIPOS technology forms islands of silicon isolated from a silicon substrate by (oxidised) porous silicon. The larger refractive index of the silicon islands suggests their use as optical waveguides. Sets of these silicon islands have been fabricated and the anticipated waveguiding has been observed at wavelengths of 1.15 and 1.3 μm in the silicon islands. However, the dominant waveguiding in these FIPOS structures is observed in the porous silicon between the silicon islands, close to the sample surface. A simple dynamic model of the anodisation process has been developed to explain the origin of this unexpected waveguiding. 相似文献
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