牛血清中钾钠氯成分分析标准物质的研制及应用

介绍了具有高低浓度水平的牛血清中钾钠氯成分分析标准物质的研制过程及应用范围.该标准物质以同一实验室采用3种方法定值,基于其临床应用特点,除了对均匀性、稳定性评定外,还对该标准物质的定值方法与临床常规方法的可互换性进行评价.该标准物质作为血清中钾钠氯量值溯源的载体,可以应用于临床电解质检测的校准、方法评价以及质量控制.     

汽车尾气监测用气体标准物质的研制

根据欧洲Ⅵ号标准,研制出低浓度汽车尾气监测用气体标准物质.该标准物质采用GB/T 5274-2008《气体分析校准用混合气体的制备称量法》中规定的方法制备并计算定值,采用气相色谱和氮氧化物分析仪对标准气体的均匀性和稳定性进行了考察,并对称量法制备过程的不确定度进行了分析评价.所制备的汽车尾气监测用气体标准物质与标准样品进行了比对,从而确保了所研制气体标准物质的量值准确可靠.     

痕量一氧化氮标准物质的研制

采用重量法研制了0.100μmol/mol的痕量氮中一氧化氮气体标准物质,其扩展不确定度为10%。在稀释气纯度分析时,采用标准添加法对纯化后的高纯氮中一氧化氮进行了准确定值,解决了痕量气体标准物质定值的难题。在长期稳定性考察时发现,气瓶中痕量一氧化氮量值随时间逐渐降低,1年内量值变化范围在4%~8%之间,并根据此结果进行了因素分析。     

福建省宁德核电周围海域海水中~3H水平分析

环境中氚的来源主要与核电的生产运行有关,随着福建省核电的发展,氚的排放对环境和公众健康的影响越来越受到社会和民众的关注,所以加强核设施核电站周围的氚的监测变得越发重要。本文分析了宁德核电自运行以来,2013至2017年核电周围海域以及福州黄岐对照点的海水中氚的活度浓度水平。结果显示宁德核电周围海域海水氚的活度浓度基本处于本底水平,个别点位略高于本底,但没有发现氚的累积趋势。     

总余氯标准物质研制北大核心CSCD

余氯是水质监测的一个重要指标,是评判水质好坏的重要参数。为此,研制了国家二级总余氯标准物质GBW(E)084725、GBW(E)084726。针对常用的总余氯测量方法,从中选取适合标准物质定值的测试方法,并对测试方法进行方法学研究。分别对2种浓度总余氯标准物质进行了均匀性和稳定性检验。方差检验F值均小于列表临界值,表明该标准物质均匀性良好。在6个月的稳定性考察期内,2种含量的标准物质在统计学上无明显变化,进行10天短期高低温模拟实验,2种含量的标准物质在统计学上也无明显变化,说明2种标准物质稳定性良好。采用氧化还原滴定法进行标准物质定值,量值分别为50 mg/L和500 mg/L,相对扩展不确定度分别为0.9%和0.5%。     

比表面积标准物质的定值和不确定度的评定

标准物质的定值就是赋予标准物质特性量值的过程,标准物质作为计量器具的一种,它能复现、保存和传递量值,保证在不同时间和空间下量值的可比性和一致性。对于比表面积标准物质,目前国内外还无法进行绝对方法测量。现阶段,国内外比表面积标准物质的定值过程均采用多家实验室协同定值的方法。本文以国家纳米科学中心研制的纳米级氧化铝比表面积标准物质为实例,对比表面积标准物质的定值过程以及不确定度评定进行了详细介绍。     

氮中乙烷气体标准物质的研制

本文介绍了氮中乙烷气体标准物质制备的原理和过程,运用气相色谱仪对该气体标准物质进行比较法定值,同时对研制气体标准物质的压力变化均匀性以及储存时间稳定性考察,以及对引入的不确定度进行计算评估.试验结果表明研制的气体标准物质量值准确可靠,在浓度范围内具备良好的均匀性和稳定性,技术指标达到了项目预期目标.     

16种挥发性有害有机物混合标准气体研制

采用称量法配制了异丁烷、二氯甲烷、苯等16种室内挥发性有害有机物的混合标准气体,各物质浓度为1ppm,平衡气为氮气。标准气体采用天平称量定值,通过实验室内和实验室间气相色谱法比对分析考察其配制准确性,并通过各物质浓度随时间及瓶内压力的变化考察了其浓度的均匀性和稳定性。结果表明我们研制生产的室内挥发性有害有机物混合标准气体量值准确,均匀性、稳定性好,各项技术指标满足国家对二级标准物质的要求。     

气载氚监测仪校准用氚化甲烷体积活度测量方法及其不确定度分析

针对气载氚监测仪校准用气体参考源氚化甲烷,提出其体积活度测量方法,用催化氧化燃烧炉将其转化为氚化水,用二级串联鼓泡器收集氚化水,并用液体闪烁计数器测定活度,从而确定气体参考源氚化甲烷体积活度,并进行了不确定度分析测定实验室已有氚化甲烷的体积活度为17.4 MBq/m3,不确定度为6.4％(k=2),符合GBT 3015...     

第一次全国液体闪烁计数器比对与计量器具管理

一、前言液体闪烁(LS计数法是放射性活度计量的重要方法之一,主要测量~3H、~(14)C等一类的低能β核素,也可测量某些β-γ、电子俘获核素。LS计数器和LS标准源属于计量法规定的计量器具,中国计量科学研究院(NIM)已建立了4πβ(LS)和4πβ(LS)-γ符合国家活度基准装置,刻度了~3H、~(14)C标准溶液,研制了相应的LS标准源。目前全国约有1000台LS计数器。为了保证放射性活度量值的统一和可靠,NIM于1988年10月至1989年10月组织了第一次全国LS计数器测量~3H、_(14)C的活度比对,有28个实验室参加,测量了~3H(正十六烷)15瓶、     

Tritium in the urine in Finnish people

Tritium in urine was analysed from 227 randomly selected Finnish adults. The people were 18 to 65 of age. Urine samples were collected over night. The mean activity concentration of tritiated water in urine was 2.5 Bq l(-1) and the maximum activity concentration 18.3 Bq l(-1). The minimum detectable activity varied from 1.5 to 2.3 Bq l(-1). Because organically bound tritium is approximately 10% of the total tritium, its concentration was below the detection limit and could be ignored. The mean effective dose for Finnish people from tritium was 2.4 x 10(-3) microSv y(-1).     

液态金属包层中氚提取技术的研究进展

为了完成ITER液态金属包层氚提取系统（TES）的设计,针对液态包层材料——液态锂、液态锂铅、盐溶液和氟化物盐中提取氚的方法进行了调研。调研结果表明：钇粒子床法和溶盐萃取法适用于液态锂中氚的提取;膜渗透法、鼓泡器法和钠回路附设冷阱法对液态锂铅中的氚提取是很有希望的,尽管氚扩散通过锂铅合金边界层的速率缓慢,增大了氚提取的技术难度,但鼓泡器法具有更高的气一液间接触面积,自90年代以来技术发展最为成熟;氦气清洗和真空萃取法已成功运用于氟化物盐包层中氚的提取。尽管任何一种氚提取方法都有工程化的现实前景,但为解决氚提取系统中杂质影响和各种相互作用的问题,开展材料和基础化学方面的广泛研究是必要的。     

An improved method for Organic Bound Tritium (OBT) determination in urine samples

The Organic Bound Tritium (OBT) amount in the body may induce changes in the evaluation of the internal exposure to tritium, due to its different retention time relative to HTO. OBT measurements for urine are not performed routinely, mainly because of the lengthy work needed in preparation of the samples, when using the standard oxygen combustion method. A simpler and more rapid method based on liquid scintillation counting (LSC) was employed, and an evaluation was performed to check its suitability for urine samples. The principle of the proposed method is based on subtracting the LSC counts of the water phase sample (HTO) from the total activity of the urine sample (OBT+HTO). A good correlation was found between the results obtained when applying the proposed direct method and the Gold standard method. The minimum detectable activity when using this method was determined.     

Monte Carlo simulation of gas flow through the KATRIN DPS2-F differential pumping system

The Karlsruhe Tritium Neutrino experiment (KATRIN) is a large vacuum system and aims to measure the electron neutrino mass from the β decay of tritium with unprecedented sensitivity. To achieve this purpose, the tritium gas flow has to be significantly reduced along the beamline by means of a modular differential pumping system. This paper studies systematically the vacuum performance of one of the differential pumping systems (known as DPS2-F) based on turbomolecular pumps. The flow reduction rates in the complete system are described by a matrix equation as a function of the capture factor of the turbomolecular pumps employed. The results show that a total reduction factor greater than 10⁵ can be attained, which is one of the prerequisites to achieve XHV conditions in the spectrometers used in the downstream end of the experiment.     

双氧法测量烟气再循环率及不确定度分析

为准确测量、计算得到烟气再循环率,在燃气组分及浓度不变的情况下,基于化学反应平衡方程式推导得到烟气再循环率的计算公式,进而提出测量燃气锅炉烟气氧浓度和烟气-空气混合气氧浓度的双氧法。为定量分析测量结果的质量,基于国标中的GUM法对双氧法进行不确定度评定,并根据不确定度要求为仪器选择提出指导意见。研究发现,当烟气氧浓度测量结果为1.91%、混合气氧浓度测量结果为18.64%时,通过双氧法计算烟气再循环率R为13.45%,扩展不确定度为1.56%。混合气氧浓度测量不确定度对双氧法扩展不确定度影响很大,在选择测量仪器时,混合气氧浓度测量仪器的扩展不确定度可小于烟气氧浓度测量仪器。     

Environmental transportation of tritium and estimation of site-specific model parameters for Kaiga site, India

Tritium content in air moisture, soil water, rain water and plant water samples collected around the Kaiga site, India was estimated and the scavenging ratio, wet deposition velocity and ratio of specific activities of tritium between soil water and air moisture were calculated and the results are interpreted. Scavenging ratio was found to vary from 0.06 to 1.04 with a mean of 0.46. The wet deposition velocity of tritium observed in the present study was in the range of 3.3E-03 to 1.1E-02 m s(-1) with a mean of 6.6E-03 m s(-1). The ratio of specific activity of tritium in soil moisture to that in air moisture ranged from 0.17 to 0.95 with a mean of 0.49. The specific activity of tritium in plant water in this study varied from 73 to 310 Bq l(-1). The present study is very useful for understanding the process and modelling of transfer of tritium through air/soil/plant system at the Kaiga site.     

热电厂连续监测系统CEMS烟气污染物测量不确定度研究

烟气排放连续监测系统(CEMS)已经广泛运用于热电联产机组烟气污染物排放监测中,并且测试数据实时上传到生态环境部门。为了评估某热电厂CEMS系统监测数据的准确度和可信度,分析了该系统中影响烟气污染物测量不确定度分量因素,主要包括零点漂移、量程漂移、示值误差、测量误差、标准气体组分浓度和测量重复性。结果表明当包含因子 k=2,置信概率为95%时,SO2、NO和NO2的扩展不确定度分别为2.28mg/m³、3.50mg/m³和0.50mg/m³。由于参比法与CEMS对烟气监测的采样方式不同,使测量误差引入的不确定度分量最大。     

基于TDLAS的气体远程测量技术在采煤机瓦斯保护上的应用研究

TDLAS技术指的是利用二极管激光器的波长特性,扫描待测气体,从而获得待测气体特征曲线进而获得气体的浓度信息。介绍了瓦斯的远程遥测技术的系统构成,理论基础。讨论了气体的远程遥测技术在采煤机瓦斯保护模块上应用的可行性与必要性。     

Radon in soil gas--investigation and data standardisation at radon reference sites, Czech Republic

Radon risk mapping at building sites in the Czech Republic indicate an advisable level of protection of buildings against the penetration of radon from the geological basement. Various techniques and instruments are used for the measurement of radon in soil gas. A national radon chamber and three radon reference sites in Central Bohemia enable radon data standardisation. Tests of field radon measurements and the reported radon activity concentration in soil gas at the reference sites are based on comparisons with other organisations and with a database of reference site measurements. The radon reference sites have been used for various investigations of radon in soil gas during the period 2000-07.