逻辑函数最大项展开式和CRM展开式的转换

在逻辑函数的CRM展开式和两种新运算基础上，对函数量大项展开系数和CRM展开系统(dj系数)之间的关系作了较详细的讨论，并提出了两者的矩阵转换法，快速转换法和直接代入转换法，具备较好的实用性．     

Accreditation of reference material producers: the example of IRMM's Reference Materials Unit

The potential approaches for third-party assessment of reference material producers are revisited and the activities of the Reference Materials (RM) Unit of the Institute for Reference Materials and Measurements (IRMM) to obtain accreditation to ISO Guide 34 and ISO 17025 are described. Accreditation was related to the Unit as all matrix RM activities of the institute are concentrated there. A management system was established that allows sufficient flexibility to be applicable to a wide range of RMs while being precise enough to ensure compliance with ISO Guides 30, 31 and especially 34 and 35. Accreditation was achieved in 2004 with independent scopes for testing and RM production and was confirmed and extended in 2005. The key aspects of the RM Unit's management system for RM production are presented. Presented at BERM-10, April 2006, Charleston, SC, USA     

Preservation of sensitive CRMs and monitoring their stability at IRMM

Over the years, the nature of CRMs has changed considerably. Recently, more and more CRMs have been certified in their "natural" form, that is processed as little as possible, with analytes at their natural concentration level. This and the trend towards certified properties other than the concentrations of clearly defined molecules/elements have made guaranteeing stability of CRMs and estimating a shelf life an even more important issue for reference material producers than it has been before. One way to meet this challenge is to take more care in processing, storage and dispatch of CRMs. At IRMM, approximately 20 % of the RMs are stored at –20 °C or below and about 10% require cooled transportation. In addition, increased efforts for assessing stability are needed. Shelf lives are estimated using addition of an uncertainty component based on real-temperature stability studies rather than by accelerated stability studies. These pre-certification efforts are complemented by a stability-monitoring program, which at IRMM includes 80 % of the non-nuclear and non-isotopic materials. Although the costs for these efforts are high in absolute terms, they are only a minor and indispensable contribution to the total costs of CRM production.     

关于铀同位素标准物质的几个问题

讨论了铀同位素标准物质(UIRM)研制中的一些技术问题,如IRM中同位素丰度的定值,IRM不确定度的影响因素等,并介绍了国内外UIRM研制情况。     

Indirect determination of soluble trace elements in certified reference materials by neutron activation analysis

Since 1983 we have analyzedaqua regia extracts from environmental reference materials of 5 different soils and 4 different sludges by neutron activation analysis. Aqua regia as such is not accepted for irradiation in a nuclear reactor, and therefore the solution has to be evaporated to dryness, mixed and dried to constant weight before an aliquot can be taken and subjected to instrumental neutron activation analysis (INAA). Results for leachable Cr and Zn were found to display greater variability than results for total contents of these elements, and the reasons for this will be discussed.For the 1994 certification campaign for one soil and two sludges we have chosen to determine the total content of trace elements in these reference materials by INAA before and afteraqua regia leaching. The leachable contents are then found indirectly as a difference between the two results; in this way we eliminate the sources of uncertainty associated with the drying and handling of theaqua regia extracts, and we reduce the contributions from counting statistics.     

分析用标准样品氟铃脲的合成、纯化及表征

合成了氟铃脲农药粗品,通过活性炭吸附、重结晶进行初步纯化;然后采用柱层析分离技术,以硅胶为填料,乙酸乙酯／石油醚（30～60℃）（1：3,V／V）为展开剂（Rf≈0．5）进行提纯。用紫外光谱（UV）、红外光谱（IR）、核磁共振（^1H NMR,^13C NMR）及质谱（MS）进行了结构表征;以高效液相色谱法测得该试样纯度在99％以上。     

有机成分标准物质的研究

列出了国家标准物质研究中心最近研制的有机成分标准物质。高纯度、定值准确可靠、良好的溯源性和系列性是这些标准物质的特点。对其应用作了介绍,并指出了将来的研究方向。     

应用Markov链方法分析销售策略

本简单地分析了销售的过程，利用认知心理得到的销售状态指标和Markov链在Pfeifer工作的基础上建立的客户关系模型，对几种不同的销售策略进行了比较。分析结果表明，在与客户关系不好的情况下．采用先改善与客户的关系、后实施销售活动效果比直接销售好些。     

Certification of the mass fractions of Pt, Pd and Rh in a used car catalyst reference material

The high economic value of catalysts containing the platinum group elements platinum, rhodium and palladium as active components causes the need to be able to measure the precious metal loading with small uncertainty and to have suitable certified reference materials fulfilling high demands on the quality of the certified values. In European Reference Material ERM^®-EB504, a used cordierite-based car catalyst material, mass fractions of platinum, palladium and rhodium were certified. The raw material was milled, homogenised and annealed before analysis. Seventeen laboratories experienced in precious metals analysis participated in the certification interlaboratory comparison, most of them analysing with inductively coupled plasma optical emission spectrometry using different sample pretreatment techniques. Homogeneity testing was carried out using X-ray fluorescence spectrometry. The certified mass fractions of Pt, Pd and Rh and their expanded uncertainties (k = 2) in ERM^®-EB504 are (1777 ± 15), (279 ± 6) and (338 ± 4) mg/kg respectively.     

新型镁合金Mg-Al-Zn-Y光谱标准样品的制备和定值

采用双层安全炉熔炼镁合金和环壁式除渣法清除结晶器中的氧化皮和夹渣等技术,研制了新型镁合金Mg-Al-Zn-Y光谱标准样品.考察了标准样品的均匀性和稳定性,该标准样品有效期为5年.使用先进的数据处理软件(StndMtrl),对多家单位协作分析定值原始数据进行检验和计算,得到标准样品的标准值和标准偏差.用化学法对标准样品进...