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排序方式: 共有278条查询结果,搜索用时 15 毫秒
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H. Brundiers R. Hartung K. Runge O. Schaile C. Weber F. Brun G. Carles M. Cribier J.R. Hubbard G. Laurens L. Moscoso A. Muller S. Zylberajch L. Fluri 《Physics letters. [Part B]》1976,64(1):107-110
A search for exotic mesons has been carried out at the CERN Omega spectrometer. The baryon-exchange reaction π+p → Λ + x++ was studied at 12 GeV/c incident beam momentum. No evidence was found for the existence of doubly-charged strange mesons. The upper limit (95% confidence level) for this reaction is 60 nb for exotic mesons with squared masses from 1 to 7 (GeV/c2)2 and 150 nb for 7 to 13 (GeV/c2)2. These limits are of the same order of magnitude as the exotic cross-sections expected from two-component duality arguments. 相似文献
93.
P.L. Woodwarth D. Treille A.S. Thompson R. Strub P. Sonderegger C. Palazzi-Cerrina W.A. Mitaroff R. Kumar I.R. Kenyon G. Irwin J.R. Hubbard M. Houlden B.R. French L. Fluri G. De Rosny M. Cribier J.K. Bienlein 《Physics letters. [Part B]》1976,65(1):89-91
We have observed φ production in π?p interactions at 19 GeV/c with (44±10) events in the final state φπ+π?π?p and (45±9) events in φK+K?π?p. The production ratios φπ+π?π?p/ωπ+π?π?p ≈ 0.005 and φK+K?π?p/?°K+K?π?p ≈ 0.45 agree with Zweig-rule expectations. 相似文献
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Pattern formation in a 2D simple chemical system with general orders of autocatalysis and decay 总被引:2,自引:0,他引:2
In this paper, we investigate pattern formation in a coupledsystem of reactiondiffusion equations in two spatialdimensions. These equations arise as a model of isothermal chemicalautocatalysis with termination in which the orders of autocatalysisand termination, m and n, respectively, are such that 1 <n < m. We build on the preliminary work by Leach & Wei(2003, Physica D, 180, 185209) for this coupled systemin one spatial dimension, by presenting rigorous stability analysisand detailed numerical simulations for the coupled system intwo spatial dimensions. We demonstrate that spotty patternsare observed over a wide parameter range. 相似文献
99.
A description of the DOE Radionuclide Aerosol Sampler/Analyzer for the Comprehensive Test Ban Treaty
H. S. Miley S. M. Bowyer C. W. Hubbard A. D. McKinnon R. W. Perkins R. C. Thompson R. A. Warner 《Journal of Radioanalytical and Nuclear Chemistry》1998,235(1-2):83-87
Radionuclide monitoring, though slower than vibrational methods of explosion detection, provides a basic and certain component of Comprehensive Test Ban treaty (CTBT) verification. Measurement of aerosol radioactive debris, specifically a suite of short-lived fission products, gives high confidence that a nuclear weapon has been detonated in or vented to the atmosphere. The variable nature of wind-borne transport of the debris requires that many monitoring stations cover the globe to insure a high degree of confidence that tests which vent to the atmosphere will be detected within a reasonable time period. To fulfill the CTBT aerosol measurement requirements, a system has been developed at PNNL to automatically collect and measure radioactive aerosol debris, then communicate spectral data to a central data center. This development has proceeded through several design iterations which began with sufficient measurement capability (<30 μBq/m3 140Ba) and resulted in a system with a minimal footprint (1 m×2 m), minimal power requirement (1600W), and support of network infrastructure needs. The Mark IV prototype (Fig. 1) is currently the subject of an Air Force procurement with private industry to partially fulfill US treaty obligations under the CTBT. It is planned that the system will be available for purchase from a manufacturer in late 1997. 相似文献
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