排序方式: 共有16条查询结果,搜索用时 15 毫秒
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Atkins R Benbow W Berley D Blaufuss E Coyne DG DeYoung T Dingus BL Dorfan DE Ellsworth RW Fleysher L Fleysher R Gisler G Gonzalez MM Goodman JA Haines TJ Hays E Hoffman CM Kelley LA Lansdell CP Linnemann JT McEnery JE Miller RS Mincer AI Morales MF Nemethy P Noyes D Ryan JM Samuelson FW Parkinson PM Shoup A Sinnis G Smith AJ Sullivan GW Williams DA Wilson ME Xu XW Yodh GB 《Physical review letters》2005,95(25):251103
Gamma-ray emission from a narrow band at the galactic equator has previously been detected up to 30 GeV. We report evidence for a TeV gamma-ray signal from a region of the galactic plane by Milagro, a large-field-of-view water Cherenkov detector for extensive air showers. An excess with a significance of 4.5 standard deviations has been observed from the region of galactic longitude l E (40 degrees, 100 degrees) and latitude /b/ < 5 degrees. Under the assumption of a simple power law spectrum, with no cutoff in the EGRET-Milagro energy range, the measured integral flux is phi gamma(>3.5 TeV) = (6.4 +/- 1.4 +/- 2.1) x 10(-11) cm(-2) s(-1) sr(-1). This flux is consistent with an extrapolation of the EGRET spectrum between 1 and 30 GeV in this galactic region. 相似文献
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Ion chromatography on-chip 总被引:3,自引:0,他引:3
Murrihy JP Breadmore MC Tan A McEnery M Alderman J O'Mathuna C O'Neill AP O'Brien P Avdalovic N Haddad PR Glennon JD Advoldvic N 《Journal of chromatography. A》2001,924(1-2):233-238
On-chip separation of inorganic anions by ion-exchange chromatography was realized. Micro separation channels were fabricated on a silicon wafer and sealed with a Pyrex cover plate using standard photolithography, wet and dry chemical etching, and anodic bonding techniques. Quaternary ammonium latex particles were employed for the first time to coat the separation channels on-chip. Owing to the narrow depths of the channels on the chip, 0.5-10 microm, there were more interactions of the analytes with the stationary phase on the chip than in a 50-microm I.D. capillary. With off-chip injection (20 nl) and UV detection, NO2-, NO3-, I-, and thiourea were separated using 1 mM KCl as the eluent. The linear ranges for NO2- and NO3- are from 5 to 1000 microM with the detection limits of 0.5 microM. 相似文献
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On-chip definition of picolitre sample injection plugs for miniaturised liquid chromatography 总被引:1,自引:0,他引:1
O'Neill AP O'Brien P Alderman J Hoffman D McEnery M Murrihy J Glennon JD 《Journal of chromatography. A》2001,915(1-2):259-263
High-speed counter-current chromatography was applied to the preparative separation and purification of naphthopyranone glycosides from a crude 70% ethanolic extract of the capitula of Paepalanthus microphyllus. The solvent system used was composed of water-ethanol-ethyl acetate-hexane (10:4:10:4, v/v). This technique led to the separation of four different naphthopyranone glycosides in pure form in only 7 h. 相似文献