排序方式: 共有19条查询结果,搜索用时 319 毫秒
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White DB Tippens WB Abegg R Baldisseri A Boudard A Briscoe W Fabbro B Garçon M Hermes EA Jacobs WW Kessler RS Lytkin L Mayer B Nefkens BM Niebuhr C Petrov AM Poitou J Saudinos J Tomasi-Gustafsson E van der Schaaf A van Oers WT Vigdor SE Wang M 《Physical review D: Particles and fields》1996,53(11):6658-6661
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Richard James Christopher Brown N. Pirrone C. van Hoek M. Horvat J. Kotnik I. Wangberg W. T. Corns E. Bieber F. Sprovieri 《Accreditation and quality assurance》2010,15(6):359-366
A standard method for the measurement of mercury in deposition is currently being finalised by Working Group 25 of the European
Committee for Standardisation’s Technical Committee 264 ‘Air Quality’, in response to the requirements of the European Union’s
Fourth Air Quality Daughter Directive. This paper reports the results of a field measurement programme which was undertaken
to assess the uncertainty of the proposed standard method, define its working range and determine its compliance with the
required data quality objectives of the Fourth Air Quality Daughter Directive. 相似文献
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Elemental mercury vapour in air: the origins and validation of the ‘Dumarey equation’ describing the mass concentration at saturation 总被引:1,自引:0,他引:1
Ronny Dumarey Richard J. C. Brown Warren T. Corns Andrew S. Brown Peter B. Stockwell 《Accreditation and quality assurance》2010,15(7):409-414
The Dumarey equation has been the dominant relationship used to calculate the mass concentration of saturated elemental mercury
vapour in air for the calibration of mercury vapour measurement equipment for over 25 years. However, the origin of the equation,
and the validation data supporting its accuracy have never been published. This paper addresses that deficiency, compares
the Dumarey equation with other data sets to which it has been wrongly attributed in the past, and describes why it remains
superior to the use of mercury vapour pressure data in combination with the ideal gas law, for the purposes of calibrating
mercury vapour measurement equipment. 相似文献
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采用时齐马尔可夫链方法给出了一种评估教师教学水平的方法,对文[1]所给方法做了适当的改进,拓宽了该方法的应用范围,在多民族院校,使用本法可以克服由于学生基础不同等多方面的原因造成难以比较教师教学水平的难题. 相似文献
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The potential of coupling anion-exchange high-performance liquid chromatography, hydride generation and atomic fluorescence spectrometry (HPLC–HG–AFS) for arsenic speciation is considered. The effects of hydrochloric acid and sodium tetrahydroborate concentrations on signal-to-background ratio, as well as argon and hydrogen flow rates, were investigated. Detection limits for arsenite, dimethylarsinic acid (DMA), monomethylarsonic acid (MMA) and arsenate were 0.17, 0.45, 0.30 and 0.38 μg l−1, respectively, using a 20-μl loop. Linearity ranges were 0.1–500 ng for As(III) and MMA (as arsenic), and 0.1–800 ng for DMA and As(V) (as arsenic). Arsenobetaine (AsB) was also determined by introducing an on-line photo-oxidation step after the chromatographic separation. In this case the limits of detection and linear ranges for the different species studied were similar to the values obtained previously for As(V). The technique was tested with a human urine reference material and a volunteer's sample. © 1998 John Wiley & Sons, Ltd. 相似文献