被动采样器在采样过程中空白污染来源的确认及控制

在博物馆微环境污染气体被动采样过程中,常出现被动采样器空白值高及易被污染的问题。针对这些问题,研究者对被动采样整个环节中涉及的进样瓶、提取瓶以及采样器各部件单元进行了空白分析,同时考察了不同制样环境、不同提取环境、不同温度烘干的滤纸对采样器空白值的影响,最终明确了采样器中不同污染离子的来源,提出了控制方案,优化了制样方法,有效降低了整体空白值,出现污染的概率从30%左右降低至5%,为博物馆污染气体采样分析提供了可靠的技术支持。     

时控恒流量采样器的研制

针对目前国产小型采样器 2 4小时采样 ,因连续在博物馆陈列室等处用电存在的不安全性、采样位置受电源位置限制以及流量控制不稳的缺陷 ,根据博物馆实际检测采样的特殊需要 ,自行研制了小型时控恒流量采样器。采样器主要有定时控制、电机控制、电源检测、模式开关和气泵等部分组成。通过电路的特殊设计 ,采取间隙式采样模式以保证连续采样无需外接电源 ,解决电池供电随着使用时间的增加电压下降可能引起采样流量变化的问题。通过电路中稳速系统设计 ,使采样器工作在一确定的电压之上 ,保证电机转速稳定 ,使采样流量不受采样管阻力影响 ,从而保证采样精度。采样器经半年多实际应用最大相对误差为 2 .5 %。能满足博物馆实际检测采样要求。     

被动采样在考古发掘现场大气监测中的应用

通过对被动采样器结构和原理的分析,对其在环境监测中的应用情况进行综述。论述其对环境的适用性和考古发掘现场的特点及有害气体的监测需求。认为被动采样技术在考古发掘现场有害气体的监测中具有广泛的应用前景。     

被动采样—离子色谱法对秦俑遗址环境腐蚀性气体的检测研究

本研究通过使用被动采样—离子色谱法对秦俑遗址环境中的酸碱性和氧化性气体进行检测,并与主动法检测结果进行对比,发现在较大的浓度范围和较长的采样时间内两种方法的总体结果具有一致性,且与主动法相比,被动法具有更高的空间分辨率,能反映区域范围污染物的分布情况。所以,一定条件下可以使用被动采样—离子色谱法替代主动法进行博物馆遗址环境腐蚀性气体的检测。     

博物馆文物环境用甲醛净化材料评价方法研究

博物馆文物环境因装饰材料所致甲醛污染以及由此产生对文物危害问题已被普遍关注.为了评价净化材料实际使用中对污染物去除净化能力,搭建了静态试验舱,建立了该环境中甲醛的定量分析方法.研究了甲醛溶液法和人造板散发法两种产生甲醛气体的方法,以及吸附材料不同加入方法等对净化材料评价结果的影响,研究试验舱内甲醛浓度随时间的变化规律,建立了净化材料脱附量检测方法,分别测定了活性炭和三种壳聚糖基净化材料的净化效果.结果表明,用人造板散发法产生甲醛气体方法能用于甲醛净化材料的评价,得到净化率指标反映了净化材料在实际文物环境中的应用效果,脱附量指标能直观比对和反映净化材料对污染物的吸附稳定性.     

文物藏展常用木材挥发性酸快速检测评价方法研究

各种实木和人造板是文物收藏柜和储藏柜的常用木质材料。这些木材普遍含有挥发性酸,是影响文物藏展环境的主要因素之一。为检测评价文物藏展常用木材的挥发性酸特征,实验采用研发的"无动力扩散采样一离子色谱"检测技术,在密闭空间中以40℃恒温加速挥发,无动力扩散采样4h,并用离子色谱双等度分析方法半定量检测挥发性酸。探讨了该项快速评价方法的相关实验参数及其确定方法,检测了14种常用木材。结果显示,红橡、樟木和经过防腐处理的椴木、棱柱木中的甲酸与乙酸的挥发量较高,单位表面积乙酸挥发量达到4mg·m~(-3)·mm~(-2)以上,甲酸挥发量也超过0.5mg·m~(-3)·mm~(-2),应当慎用。为控制木材挥发物影响文物保存环境,试验用铝塑膜包覆封闭木材并作比对检测,结果表明铝塑膜对甲酸、乙酸挥发的阻隔效果明显,甲酸、乙酸单位表面积乙酸挥发量均小于0.2 mg·m~(-3)·mm~(-2)。     

固体主动采样法用于检测博物馆内二氧化氮

为了寻找适合博物馆柃测要求的NO2测定方法,选择分子筛为填充担体,TEA与DEA为复配吸收剂,采样管柱长为5cm,管径为5．5mm,采样流速为100—160ml／min,建立了固体主动采样法。经与常规溶液法和仪器法测定结果比较,三种采样法测得的NO2浓度在精密度和总体均值上均无显性差异,具有高度相关性和可比性。它们之间的回归直线关系存在,可用于环境现场二氧化氮的检测。     

武汉博物馆文物保存环境研究

为全面了解武汉博物馆的文物保存环境现状,科学评价该馆文物库房环境达标试点工程的成效,总结实践经验,服务我国馆藏文物保存环境改善工作,采用相关检测设施和仪器分析手段,针对该馆的改造新文物库房、未改造老库房、文物储藏柜、包装囊盒、陈列展厅、文物展柜内的环境质量,检测了其中的温度、相对湿度、甲醛浓度、板材的木材含水率、可见光照度以及紫外辐照强度等指标,并对环境中的酸性气体和VOC浓度进行了采样分析。检测研究结果表明,武汉博物馆达标改造工程对库房温湿度和光照水平的控制成效明显,基本达到了文物保护要求;增添使用的文物储藏柜、包装囊盒、活性炭吸附材料等具有一定的微环境调控效果。由于装饰材料和橱柜材料等散发污染物的影响、恒温恒湿系统的间歇式运转模式、部分老库房和展厅采用无防护自然采光设计等原因,现文物保存环境中还存在主要污染气体浓度普遍偏高、湿度呈现短周期性波动、局部光照水平偏高等情况。对此,给出了一些建议。     

城市环境空气质量现状及污染防治策略探讨

我国城市人口密集、工业企业众多,在生产生活中会排放大量废气,对城市的空气环境造成极大地污染.此外,受城市建筑环境的影响,大量高层建筑的存在也不利于污染物的扩散,进一步加剧了城市化进程中城市空气的污染程度.在此情况下,城市空气质量改善成为重要的民生问题.本文就我国城市空气的现状进行具体分析,分析在城市内做好空气污染防治的...     

博物馆内主要污染气体的检测及其分布状况研究

文物近几十年来遭受自然损害渐趋明显,纸张酸度增加、颜料染料褪色加剧、石刻风化速度加快、金属腐蚀加速等等,这些都与大气污染有关。污染气体检测方法的研究是为评价和治理文物环境,为研究环境污染因素对文物造成影响提供依据的基础。目前国内外环境检测部门采用的溶液吸收采样法不适宜在博物馆进行长期连续监测和对污染气体分布状况进行研究,尤其     

Development of a multibottle gas‐tight fluid sampler WHATS II for Japanese submersibles/ROVs

This paper summarizes the design and performance of our recently developed gas‐tight fluid sampler WHATS II, especially designed to collect seafloor venting gas‐rich fluid from submersibles/remotely operated vehicles (ROVs). It consists of four 150‐cm³ stainless steel sample cylinders, eight ball valves, a motor‐driven arm, a rail, a peristaltic pump, a control unit, and a flexible Teflon tube connected to a titanium inlet tube. All the parts have been designed to be used at undersea as deep as 4000 m. The motor‐driven arm on the rail can open and close each of the four cylinders. By pumping out distilled water that has filled an open cylinder and the dead spaces of the sampler, we can fill the cylinder with sample fluid. WHATS II can take a maximum of four different gas‐tight samples in a series. The whole operation can be arranged from the cabin, etc., of a submersible/ROV. Use of only one motor to operate eight valves makes the sampler small, light (21 kg in sea water), and easy to handle. In addition, the sampler is able to collect an almost uncontaminated gas‐tight sample from the seafloor. To date, the sampler has been used in more than 90 dive surveys by Japanese submersibles/ROVs, including Shinkai 2000, Shinkai 6500, and Hyper Dolphin, with a success rate of >90%.     

Molecular transport of methane, ethane and nitrogen and the influence of diffusion on the chemical and isotopic composition of natural gas accumulations

Laboratory experiments have been performed to determine diffusion coefficients of natural gas components (methane, ethane and nitrogen) and isotope fractionation effects under simulated in situ pressure (up to 45 MPa effective stress) and temperature conditions (50–200°C) in water‐saturated pelitic and coarse‐grained rocks. Effective diffusion coefficients of molecular nitrogen (0.39 × 10^?11 to 21.6 × 10^?11 m² sec^?1 at 90°C) are higher than those for methane (0.18 × 10^?11 to 18.2 × 10^?11 m² sec^?1 at 90°C). Diffusive flux rates expressed in mass units are generally higher for N₂ than for CH₄. Both methane and (to a lesser extent) nitrogen diffusion coefficients decrease with increasing total organic carbon (TOC) content of the rock samples because of sorption processes on the organic matter. This effect decreases with increasing temperature. Effective diffusion coefficients increase upon a temperature increase from 50 to 200°C by a factor of four. Effective diffusion coefficients and steady‐state diffusive flux decrease with effective stress. Stationary diffusive fluxes drop by 50–70% for methane and 45–62% for nitrogen while effective diffusion coefficients are reduced by 38% (CH₄) and 32–48% (N₂), respectively. Isotope fractionation coefficients of diffusive transport are higher for methane (?1.56 and ?2.77‰) than for ethane (?0.84 and ?1.62‰). Application of the experimental results to geological systems show that diffusive transport has only a low transport efficiency. Significant depletion of natural gas reservoirs by molecular diffusion is only expected in cases of very poor caprock qualities (in terms of thickness and/or porosity) and over extended periods of geological time. Under these circumstances, the chemical and isotopic composition of a gas reservoir will change and maturity estimates based on these parameters may be deceptive. To account for these potential effects, nomograms have been developed to estimate diffusive losses and apply maturity corrections.     

用示踪气体法检测文物展柜换气率技术研究

摘要文物展柜为文物的展示和保存提供了一个相对独立的空间,展柜密封度的高低影响着展柜内微环境调控的效果。为评价文物展柜的密封度,用示踪气体法检测展柜换气率,从检测便捷、安全和实验数据可靠角度分析比较了二氧化碳和乙烯的实验结果。结果显示,两种示踪气体均可用于检测展柜的密封度。其中,二氧化碳气体检测法比较方便,但其密度较大,易于沉降,检测结果偏低。环境湿度对二氧化碳示踪气体法检测的结果有一定影响。应用二氧化碳示踪气体法测试了多种展柜的换气率表明,各展柜的密封度有较大差别,每天换气率从0.1次到37次不等。检测结果提示,二氧化碳示踪气体法为评价展柜的密封度提供了一个简便易行的方法。     

A new method of dentine microsampling of deciduous teeth for stable isotope ratio analysis

Carbon and nitrogen stable isotope ratio analysis of dentine is a powerful tool for examining early childhood diet in past populations. Serial sampling of the dentine can reconstruct an individual's changing diet. Previous serial studies have used homogenized samples that give broad results for age categories. This study presents a new dentine microsampling technique for use in stable isotope ratio analysis that provides stable isotope signals for three important juvenile life stages: fetal life, breastfeeding, and weaning.     

Young People's Narratives of Rural-Urban Difference

Although recent research by geographers interested in children and young people has examined young people's experiences in a range of both 'rural' and 'urban' environments, the significance of narratives of rural-urban difference for young people's identities has received comparatively little attention. This paper draws on theories of narrative identity to explore how narratives of rural-urban difference (and, in particular, the cultural hierarchies created and reinforced by these narratives) are significant for the construction of young people's identities. Using empirical material drawn from two separate studies in the USA, one from a mid-sized Sunbelt city and one from rural northern Vermont, the paper examines ways in which narratives of rural-urban difference are significant for young people's senses of self, processes of 'othering', and the constitution of local youth cultures.     

Uncommon Groundings: Fred B. Kniffen's Place in Current Cultural Geography

Fred Bowerman Kniffen's academic career started in the 1920s at a time when cultural geography in North America was getting underway. For more than 60 years, Kniffen played a prominent role in its formation and elaboration. His contribution centered on material cultural studies, particularly folk housing, and the patterns and processes of the diffusion of the cultural elements of ordinary people. However, Kniffen's legacy within contemporary cultural geography extends beyond these central concerns. This essay examines Kniffen's relation to mass or popular culture studies, material culture studies, Berkeley school cultural geography and the "new" cultural geography. It considers the bases for Kniffen 's appeal to a diverse following, and suggests why his contributions will not be soon outmoded.     

The potential of bird remains for environmental reconstruction

Until relatively recently, studies of bird remains have been regarded as peripheral to mainstream research on early archaeological and palaeontological sites, rather than a potentially crucial factor in the reconstruction of the past environments in which hominids and other larger mammals were present This paper sets out to define the range of ecological information for a site which can be gained through study of the bird bones, using as an example the bones recovered in the excavations at Gorham's Cave, Gibraltar. © 1997 John Wiley & Sons, Ltd.     

'Enlivening' Development Concepts through Workshops: A case study of appropriate technology and soil conservation

In comparison with the teaching of most other geography topics, where fieldwork can be conducted relatively easily and seminars can be based on some pre-existing knowledge and first-hand experience of the issues, the range of resources and approaches available to tutors teaching the geography of development is necessarily more limited. Tutors often have to rely more heavily on 'top-down' teaching and more passive learning approaches, such as using videos, slides and lectures. While students may gain a theoretical understanding of development concepts, issues and problems, they may be left without a deeper 'experience' of such material. This paper describes a practical workshop designed to communicate to students the idea of 'appropriate technology'. The workshop enables students to actively 'experience' a development concept rather than simply understand it in theory. It tests comprehension and understanding, through the application of a concept to real examples, stimulates discussion and debate, and draws upon problem-solving and critical thinking skills.