Multi-technique characterizations of main elements in the vehicle exhaust particles collected in a tunnel in Shnaghai

In this study,vehicle exhaust particles were collected three locations (the middle,entrance and outside) of the Dapu Road tunnel in downtown Shanghai,and the particle samples were characterized using SEM,XAFS,ICP-MS and M?ssbauer spectrometry,and the oxidative damage was assessed by plasmid DNA.Most iron-containing particles are found from vehicle exhaust,and iron oxide is the major species in all samples.Its concentration in the particles inside the tunnel is higher than that the outside particles.The iron particles inside the tunnel have higher proportion of water-soluble fraction in hydrous iron sulfate form or smaller size.ZnCl2 is the main soluble fraction in zinc-containing particles,while higher percentage of insoluble fraction existed in the particles outside of tunnel.Major species of lead-containing particles are PbSO4,Pb3(PO4)2 and PbCO3.In addition,the soluble fraction of other transition metallic elements as Ti and V is higher in the particles inside the tunnel than that outside the tunnel.The plasmid DNA assay results indicate that the particles from vehicle exhaust have a stronger oxidative damage and inflammation than that from outside of the tunnel.     

上海市钢铁工业尘单颗粒分析

用高分辨率、高灵敏度的扫描质子微探针对上海市工业尘进行单颗粒分析,研究了在颗粒物中不同元素的分布以及元素平均含量随粒径大小的变化。结果表明,Fe、Cr、Mn等元素在颗粒物中均匀分布的,而K、Ca则富集在颗粒物的表面。而且这些元素的平均含量随粒径的变化呈现出一规律性,其中大部分重金属元素（如Cu、Cr、Ni、Zn、Pb）聚集在颗粒粒径＜5μm的颗粒物上。     

Characterization and source identification of fine particulate matter in the atmosphere of downtown Shanghai using μ-SXRF and ICP-MS

To investigate the characteristic and sources of the free particulate matter (PM2.5), and the major sources affecting particulate air pollution in Shanghai, China, the individual aerosol particles were analyzed using the synchrotron radiation micro-beam X-ray fluorescence analysis (μ-SXRF), and the PM2.5 multi-elements were determined by the inductively coupled plasma mass spectrometer (ICP-MS). The results show that the mass concentration and chemical elements have seasonal variation, and the enrichment factors show that the chemical elements in the inhalable particles could come from the earth crust and anthropogenic pollution. The extent of metal pollution was assessed by comparing the measured concentrations with those reported in the literature. Nine categories of PM2.5 pollution sources identified at the center of Shanghai show that the vehicle exhaust, emission of metallurgic industry and coal combustion are important.     

Effect of indirect non-thermal plasma on particle size distribution and composition of diesel engine particles

To explore the effect of the gas source flow rate on the actual diesel exhaust particulate matter (PM),a test bench for diesel engine exhaust purification was constructed,using indirect nonthermal plasma technology.The effects of different gas source flow rotes on the quantity concentration,composition,and apparent activation energy of PM were investigated,using an engine exhaust particle sizer and a thermo-gravimetric analyzer.The results show that when the gas source flow rate was large,not only the maximum peak quantity concentrations of particles had a large drop,but also the peak quantity concentrations shifted to smaller particle sizes from 100 nm to 80nm.When the gas source flow rate was 10 Lmin-1,the total quantity concentration greatly decreased where the removal rate of particles was 79.2％,and the variation of the different mode particle proportion was obvious.Non-thermal plasma (NTP) improved the oxidation ability of volatile matter as well as that of solid carbon.However,the NTP gas source rate had little effects on oxidation activity of volatile matter,while it strongly influenced the oxidation activity of solid carbon.Considering the quantity concentration and oxidation activity of particles,a gas source flow rate of 10 L min-1 was more appropriate for the purification of particles.     

核分析技术在环境和医学研究中的应用

通过对汽车尾气颗粒物、同一污染源的不同粒径飞灰样品的分析,以及稀土元素对人和动物的毒性研究,获得了环境监测和方面的特定信息,展现了核分析技术在环境和医学中的广泛应用。     

源激发X射线荧光测定头发中Ca、Fe、Cu、Zn、Pb的方法优化

同位素源激发X射线荧光（XRF）已广泛应用于头发中的微量元素测定。中国原子能科学研究院曾经建立了源激发X射线荧光分析技术分析头发样品,Pb的检测限（LLD）约10μg/g。本工作在原来工作的基础上优化仪器参数,降低背景信号强度,提高了灵敏度,尤其是对Pb的灵敏度,使Ca、Fe、Cu、Zn、Pb的检测限分别达到19、1.2、1.1、0.62、1.1μg。首次采用V做内标元素,取样量为0.5g,仪器的短期稳定性相对标准偏差（RSD）为0.38%,长期稳定性相对标准偏差为0.98%。     

Aerosol composition and source apportionment in Santiago de Chile

Santiago de Chile, São Paulo and Mexico City are Latin American urban areas that suffer from heavy air pollution. In order to study air pollution in Santiago area, an aerosol source apportionment study was designed to measure ambient aerosol composition and size distribution for two downtown sampling sites in Santiago. The aerosol monitoring stations were operated in Gotuzo and Las Condes during July and August 1996. The study employed stacked filter units (SFU) for aerosol sampling, collecting fine mode aerosol (dp<2 μm) and coarse mode aerosol (210 mass of particles smaller than 10 μm) and black carbon concentration were also measured. Particle-Induced X-ray Emission (PIXE) was used to measure the concentration of 22 trace elements at levels below 0.5 ng m⁻³. Quantitative aerosol source apportionment was performed using Absolute Principal Factor Analysis (APFA). Very high aerosol concentrations were observed (up to 400 μg/m³ PM₁₀). The main aerosol particle sources in Santiago are resuspended soil dust and traffic emissions. Coarse particles account for 63% of PM₁₀ aerosol in Gotuzo and 53% in Las Condes. A major part of this component is resuspended soil dust. In the fine fraction, resuspended soil dust accounts for 15% of fine mass, and the aerosols associated with transportation activities account for a high 64% of the fine particle mass. Sulfate particle is an important component of the aerosol in Santiago, mainly originating from gas-to-particle conversion from SO₂. In the Gotuzo site, sulfates are the highest aerosol component, accounting for 64.5% of fine mass. Direct traffic emissions are generally mixed with resuspended soil dust. It is difficult to separate the two components, because the soil dust in downtown Santiago is contaminated with Pb, Br, Cl, and other heavy metals that are also tracers for traffic emissions. Residual oil combustion is observed, with the presence of V, S and Ni. An aerosol components from industrial emissions is also present, with the presence of several heavy metals such as Zn, Cu and others. A factor with molybdenum, arsenic, copper and sulfur was observed frequently, and it results from emissions of copper smelters.     

Heavy metal pathways and archives in biological tissue

Nuclear milli and microprobes at the Australian Nuclear Science and Technology Organisation (ANSTO) were used to determine lead accumulation in native Australian plants and animals. Three species of eucalypt plants (Eucalyptus camaldulensis, Eucalyptus globulus and Eucalyptus lesouefii), one species of salt bush (Atriplex burbhanyana) and one species each of acacia (Acacia saligna) and estuarine crocodiles (Crocodylus porosus) were investigated. Experimentally grown plants were subjected to a nutrient solution with a pH of 5 and spiked with a 200 μmol concentration of Pb. Lead concentrations in leaves of both E. globulus and E. camaldulensis showed an almost exponential decrease from the base of the main vein to the tip. Similarly, Pb concentrations decreased from the main vein to secondary veins. Concentrations of essential elements such as K, Fe, Zn and Br in the main and secondary veins were constant within experimental uncertainty. In contrast, the concentrations of Pb in the leaf veins of E. lesouefii were much lower and showed no systematic pattern. In stem and root samples the highest concentration of Pb was found in roots and stem of E. globulus and A. burbhanyana followed by E. camaldulensis. Some Pb was found in roots of A. saligna and only very low concentration in stem of the same plant. More detailed analysis of thin cross-sectional samples of roots and stem showed that Pb is present in much higher concentration in the growth area of the plant structure (i.e. meristemic region) and in relatively low concentration within the pith region and outer cortex. The osteoderms (dermal bones) of estuarine crocodiles, exposed to lead ammunition in food from the hunting activities of traditional Aboriginal owners, were sampled at two sites in Kakadu National Park, northern Australia. PIXE analyses showed enhanced, but relatively constant, ratios of Pb/Ca in the annual laminations. This was consistent with both their history of long term exposure to elevated anthropogenic Pb sources and the hypothesis that the osteoderm can be used as an archive of the crocodile's exposure to Pb during its life.     

IBA analyses and lead concentration measurements of AMS-C dated bones from two medieval sites in Italy

AMS (accelerator mass spectrometry) radiocarbon dated human bone samples recovered in the deserted medieval village of Quattro Macine, Lecce, in Southern Italy, were analyzed by PIXE (particle induced X-ray emission) and PIGE (particle induced gamma ray emission). The optimization of the PIXE-PIGE experimental set-up in term of beam energy and detection geometry resulted in the possibility to obtain information about major, minor and trace elements of the samples. Unexpectedly, all the analyzed samples showed a Pb concentration higher than 50 ppm. Two possible explanations of the measured high Pb concentration are discussed in the paper: the pre-mortem intake associated with the use of Pb-rich glazed pottery and the post-mortem intake from soil as the result of diagenetic processes.     

基于DPM模型的铅铋合金中颗粒物对管道冲蚀的数值模拟研究

基于流体力学理论研究液态铅铋合金（LBE）流体中颗粒物对管道壁面的冲蚀作用,采用Fluent软件中的离散相模型（DPM）对管壁的冲蚀进行数值模拟研究。结果表明,弯管角度、颗粒粒径、颗粒物浓度、管道的管径以及流速等对管壁的冲蚀磨损产生明显影响,其中,流速影响较大,在高流速下的冲蚀严重;弯管角度的影响显著,对直管段的冲蚀较弱,对弯管角度在30° ~ 90°之间的管道的冲蚀比较严重;颗粒粒径在1 ~ 9 μm内的微颗粒对管道冲蚀影响较小,粒径增大到10 ~ 90 μm时,冲蚀速率变化不明显,粒径增大到100 ~ 900 μm时,大直径的颗粒对管道冲蚀严重。      

Study of automobile exhaust particles by spectromicroscopy

In this paper, automobile exhaust particles of Gol and Santana 3000 were studied by spectromicroscopy.The STXM results show that the single particulate is sized at 500 nm, with the mass distribution reducing towards the center. The N 1s NEXAFS spectra of automobile exhaust particles have similar structure with those of nitrates, which can be deduced as the main chemical species of nitrogen in automobile exhaust particles. There are minor amounts of ammoniums and organic nitrogen compounds in automobile exhaust particles. A single Gol automobile exhaust particle was stack scanned in the energy range of 396-416 eV. By principal component analysis and cluster analysis, it can be deduced that there are main three chemical species of nitrogen. The particle surface consists of mainly nitrates,the inside consists of mainly ammonium and organic nitrogen compounds, and the middle layer is an intergradation consisting of mainly nitrates and organic nitrogen compounds.     

Lifecycle of palladium in Japan: for setting clearance levels of 107Pd

Research on the recycling of useful elements in spent nuclear fuels of light-water cooling reactors is progressing. Palladium (Pd), a fission product in high-level radioactive waste, is one of the elements that can be recovered and recycled. Even if the Pd recycling system is successfully established, ¹⁰⁷Pd contamination will be unavoidable. In this report, we review the lifecycle of Pd (applications, environmental levels, and human exposure) with respect to setting clearance levels for ¹⁰⁷Pd. The major applications of Pd in Japan are catalysts for automobile exhausts and chemical industries, followed by dental prostheses and electrical devices. The World Health Organization reported a daily uptake of Pd from drinking water and food of 0.03 and <2 μg person^?1, respectively. The uptake of a person with a dental prosthesis containing Pd might reach up to 15 μg day^?1. The Pd uptake by the public via inhalation of particulate matter from automobile exhaust catalysts is not as large, even in urban areas, although this industrial application is responsible for the largest portion of Pd released into the environment globally. The data presented here will be useful for setting clearance levels for ¹⁰⁷Pd.     

SIMS含铀微粒同位素比分析中多原子离子影响及消除方法研究

实际环境样品基体成分十分复杂,多原子离子对二次离子质谱(SIMS)单微粒铀同位素比分析的影响不可忽略。本文实验分析了Pb、Ni、Zn、Si的多原子离子在SIMS单微粒铀同位素比分析中的干扰,并分别采用提高质量分辨率以及根据核素离子强度扣除其多原子离子的方法对结果进行校正。结果表明：Pb和Ni的多原子离子会影响含铀微粒次同位素比的测量,对铀主同位素比的影响可忽略;Zn和Si的多原子离子对铀主、次同位素比测量均基本无影响。将质量分辨率提高至800,能完全消除Ni多原子离子的影响,Ni-CRM U030混合（Ni粉混合CRM U030）微粒²³⁴U/²³⁸U同位素比测量值与参考值之间的相对偏差基本好于5%,²³⁶U/²³⁸U同位素比测量值与参考值之间的相对偏差基本好于15%;Pb多原子离子干扰无法通过提高质量分辨率进行消除,根据Pb离子强度扣除其多原子离子后,Pb-CRM U030混合微粒的²³⁴U/²³⁸U同位素比测量值与参考值之间的相对偏差基本好于10%,²³⁶U/²³⁸U同位素比测量值与参考值之间的相对偏差基本好于50%。将以上消除干扰的方法应用于真实样品分析,结果表明,其有效消除了多原子离子带来的干扰。     

Source apportionment of single aerosol particles in the atmosphere of Shanghai city

A nuclear microprobe with high spatial resolution and high analytical sensitivity was applied to analyze atmospheric aerosol at five monitoring sites in Shanghai city.Meantime,a new pattern recognition technique,which used the micro-PIXE spectrum of a single aerosol particle as its fingerprint.was developed to identify the origin of the particle.The results showed that the major contributors to the atmosphere pollution were soil dust(31.6%) ,building dust(30.8%),and the next were vehicle exhaust(13.7%),metallurgic industry excrements(5.6%).oil combustion(5%) and coal combustion(2.3%).Besides these ,about 10% of the particles could not be identified.Based on the cluster analysis of these particles.they could be divided into eight groups.By inference,they might belong to some sub-pollution sources from soil dust,building dust and metallurgic industry excrements.Moreover,some new pollution sources from tyres and chemical plants were also revealed.     

海洋环境体系中放射性核素吸附-解吸迟滞机制研究

通过宏观吸附-解吸等温实验,系统研究了放射性核素¹¹⁰Ag^m在海洋环境中表层沉积物上的吸附动力学过程及不同沉积物浓度和核素初始浓度条件下吸附-解吸迟滞机制（吸附不可逆性）。研究结果表明：Freundlich等温吸附模型可很好地描述¹¹⁰Ag^m在海水沉积物上的吸附 解吸过程;¹¹⁰Ag^m吸附速率开始很快（0~24 h）,呈指数型增加,而后逐渐趋于平缓,体系达到吸附平衡;改变沉积物浓度会产生明显的固体浓度效应,即¹¹⁰Ag^m吸附等温线随沉积物浓度的升高而显著下降。体系解吸迟滞性可用解吸迟滞系数(TII)和解吸滞后角量化表征,在沉积物浓度0.1～3.0 g/L范围内,解吸迟滞系数和解吸滞后角先增大后减小,不可逆程度与¹¹⁰Ag^m在颗粒表面与吸附点位的结合方式及微小颗粒物相互作用团聚导致的吸附剂有效吸附表面和吸附点位减小有关;对于不同沉积物浓度吸附体系,随核素初始浓度的增加,解吸迟滞系数总体先降低后增加,体系解吸迟滞性呈先减小后增大的变化趋势,其主要受两方面因素控制：1）¹¹⁰Ag^m分子在颗粒物表面与吸附点位的结合方式;2） 在浓度梯度力作用下,¹¹⁰Ag^m分子扩散吸附导致颗粒物微孔乃至超微孔隙结构发生形变,孔隙通道形变有效锁定了内表面吸附的¹¹⁰Ag^m,无法解吸脱落从通道中扩散出来,从而使吸附体系表现出一定程度的解吸迟滞性。     

Trace element load in cancer and normal lung tissue

Samples of malignant and benign human lung tissues were analysed by two complementary methods, i.e., particle induced X-ray emission (PIXE) and total reflection X-ray fluorescence (TRXRF). The concentration of trace elements of P, S, K, Ca, Ti, Cr, Mn, Fe, Cu, Zn, Se, Sr, Hg and Pb was determined in squamous cancer of lung tissue from 65 people and in the benign lung tumour tissue from 5 people. Several elements shows enhancement in cancerous lung tissue of women in comparison to men, i.e., titanium show maximum enhancement by 48% followed by Cr (20%) and Mn (36%). At the same time trace element concentration of Sr and Pb are declaimed by 30% and 20% in women population. Physical basis of used analytical methods, experimental set-up and the procedure of sample preparation are described.     

一种调控氡子体平衡因子的高浓度单分散性气溶胶发生器的研制

为了满足氡室内氡子体辐射场的调控要求,结合蒸发冷凝法的原理,利用电子烟发生器产生的癸二酸二辛酯(DEHS)与雾化器产生的NaCl颗粒结合再冷凝的方法,研制了高浓度单分散的气溶胶发生器。将该发生器应用于中国计量科学研究院20 m³氡室,充胶1分钟后气溶胶浓度最高可达到2.26×10⁵ cm^-3,平均粒径156.8 nm,单分散性1.38,氡室内氡子体平衡因子可调控达到0.65。     

On local blockage formation in sodium cooled reactors

For LMFBR safety considerations the formation of local blockages in the reactor core is investigated since years. A summary of experimental and theoretical results is given considering e.g. granulate material sources, transport phenomena, geometrical data and technological concepts influencing blockage deposition. The experimental results show clearly that for safety relevant blockages in fuel element subchannels a sufficient mass of solid particles of the right grain size is necessary to be accumulated in a few subchannels. Transport by the primary coolant through the whole pool or loop type reactor and distribution in the lower core plenum are not expected to lead to non-fuel blockages. For fuel particle blockages canning defects have to occur first. The experiments show that in this case wire wrapping has some advantages for coolability compared to spacer grids. But here also a lot of undetected material is necessary. Assuming a high quality standard for fuel element production and e.g. a sensitive DND-system for early failure detection with subsequent removal of defect fuel elements the risk of sufficiently large local blockages with following incidental situations is very low.     

The study of chemical composition and elemental mappings of colored over-glaze porcelain fired in Qing Dynasty by micro-X-ray fluorescence

It is very difficult to measure the chemical composition of colored pigments of over-glaze porcelain by X-ray fluorescence because it contains high concentration of Pb. One of the disadvantages of our polycapillary optics is that it has low transmission efficiency to the high energy X-ray. However, it is beneficial to measure the chemical compositions of rich Pb sample. In this paper, we reported the performances of a tabletop setup of micro-X-ray fluorescence system base on slightly focusing polycapillary and its applications for analysis of rich Pb sample. A piece of Chinese ancient over-glaze porcelain was analyzed by micro-X-ray fluorescence. The experimental results showed that the Cu, Fe and Mn are the major color elements. The possibilities of the process of decorative technology were discussed in this paper, also.     

Nuclear Reactions in Semiconductors

Soft upsets in semiconductor memory devices can be produced by charged particles produced in nuclear reactions in the semiconductor or in its surrounding materials. We have calculated the particle production cross sections for incident neutrons and protons in various semiconductor materials in the energy range of 5 to 75 MeV. The common semiconductor elements and compounds all have approximately the same alpha particle production. There is also appreciable proton and heavy ion production which under some conditions may cause upsets.