Elemental Analysis of Water and Sediments By External Beam Pixe Part 4. Aliakmon River, Greece

The Aliakmon River originates in the North Western part of Greece, traverses the Western part of Macedonia, and discharges into the Thermaikos Bay in the North Aegean Sea. Proton induced X-ray emission (PIXE) method with external beam was used for the determination of the metallic elements in the waters and sediments of the Aliakmon River. the pH, dissolved oxygen, conductivity, and total phosphate and nitrate concentrations were also monitored in the water samples. Data collected for a 20-month period indicate that the Aliakmon River can be still considered as an unpolluted river.     

Seasonal comparison of moss bag technique against vertical snow samples for monitoring atmospheric pollution

This is the first study seasonally applying Sphagnum papillosum moss bags and vertical snow samples for monitoring atmospheric pollution.Moss bags,exposed in January,were collected together with snow samples by early March 2012 near the Harjavalta Industrial Park in southwest Finland.Magnetic,chemical,scanning electron microscopy-energy dispersive X-ray spectroscopy(SEM-EDX),K-means clustering,and Tomlinson pollution load index(PLI)data showed parallel spatial trends of pollution dispersal for both materials.Results strengthen previous findings that concentrate and slag handling activities were important(dust)emission sources while the impact from Cu–Ni smelter's pipe remained secondary at closer distances.Statistically significant correlations existed between the variables of snow and moss bags.As a summary,both methods work well for sampling and are efficient pollutant accumulators.Moss bags can be used also in winter conditions and they provide more homogeneous and better controlled sampling method than snow samples.     

医用诊断X线机房空气中离子浓度的调查

对乌鲁木齐地区５所医院１所卫生防疫站的医用诊断Ｘ射线机房内空气中正负离子浓度进行了调查，结果表明：透视和摄片机房空气中正负离子浓度分别为４７４±１１８，３１２±１０４（个／ｃｍ３）和４０４±１０１，２５６±７８（个／ｃｍ３）．单极系数（ｎ＋／ｎ－）分别为１．５２和１．５８。正离子浓度均高于对照组（Ｐ＜０．０１），ｎ＋／ｎ－相当于对照组的１，３７和１．４２倍。开机后空气中正离子浓度显著高于开机前浓度，ｎ＋／ｎ－开机后相当于开机前的１．６６和１．５９倍，呈现出Ｘ线机房空气中正负离子严重失调。提示应加强有害因素的防护。     

蒙脱石b轴有序度的测定及其实用意义

粉末X射线衍射测量蒙脱石结构有序度,采用v/p值法仅反映c轴方向有序度,不能代表a、b轴方向有序度。作者提出(02)反射带峰形不对称程度是b轴有序程度的直观反映,将该峰峰高(H)与2/3高宽(W)的比值定义为蒙脱石晶体结构的b轴有序度,H/W值越大,b轴有序度越高,反之,朽序度低。H/W值对蒙脱石原矿评价与应用研究有一定意义。     

碱性闪石12种阳离子占位度的X射线衍射测定

对所收集的４７个碱性闪石结构数据计算出理论Ｘ射线粉末图，同时实测出５个碱 性闪石样品的粉末图及其晶体化学占位，从这５２个样品的Ｘ射线衍射圈中选出１８条特征衍射 强度，将强度比值与各晶位各阳离子占位用多元统计分析统计出经验公式，以之作为估算未知 样品各阳离子占位的线性模型。回代实践表明，本线性模型具有较钙质闪石更高的可靠性与精 确度。预测５个实测样品的晶体化学类型与原定名对比完全符合，准确度达１００％。按国际分 类表纠正个别样品原定名的错误。在１２种阳离子占位中，估算的准确度有８种大于９０％，３种 近于９０％！唯有Ｔ位Ｓｉ的准确度仅６６％，这可能是因为所选样品中Ｔ位基本上为Ｓｉ占位，其 占位数均超过 ７．５，占位度均大于 ０.９，总变化幅度小从而降低其相关性。因 ５２个样品中，也包 含钠钙闪石亚族，故对整个闪石族用Ｘ射线衍射估算阳离子占位的问题已基本解决。     

巯基纸富集——XRF测定水中Sb(Ⅲ)和Sb(Ⅴ)

在ｐＨ６．０的ＮＨ４ＡＣ－ＨＡＣ缓冲介质中，以巯基纸吸附和富集Ｓｂ（Ⅲ），吸附Ｓｂ（Ⅲ）后的巯基纸用Ｘ射线荧光测定；吸附Ｓｂ（Ⅲ）后的溶液于１ｍｏｌ／ＬＨｃｌ介质中，以巯基纸吸附Ｓｂ（Ⅴ），并按同样方法测定Ｓｂ（Ⅴ）。     

医院放射科职工眼晶体改变的调查

通过对310例放射科工作人员晶体检查,发现其晶体改变随着专业工龄的增加而增加,晶体浑浊比率明显高于同年龄非接触X线者.X线在加速晶体混浊中起着重要作用,所以防护不可忽视.     

蒙脱石矿物的结晶度及其地质意义初探

本文用X射线粉末衍射法研究蒙脱石矿物的结晶度与其埋藏深度之间的关系,并作出地质解释。 在X射线粉末衍射图上,V/P值的大小即C轴的有序程度是蒙脱石结晶度的标志。V/P值与其生成时的深度有相关性,其相关曲线呈一似抛物线形。似抛物线的顶点位于不同的生成深度,这主要是各地区地热增温率及成矿温度不同所引起。     

Using X-ray computed tomography and micro-Raman spectrometry to measure individual particle surface area, volume, and morphology towards investigating atmospheric heterogeneous reactions

Heterogeneous reactions on the aerosol particle surface in the atmosphere play important roles in air pollution, climate change, and global biogeochemical cycles. However, the reported uptake coefficients of heterogeneous reactions usually have large variations and may not be relevant to real atmospheric conditions. One of the major reasons for this is the use of bulk samples in laboratory experiments, while particles in the atmosphere are suspended individually. A number of technologies have been developed recently to study heterogeneous reactions on the surfaces of individual particles. Precise measurements on the reactive surface area, volume, and morphology of individual particles are necessary for calculating the uptake coefficient, quantifying reactants and products, and understanding the reaction mechanism better. In this study, for the first time we used synchrotron radiation X-ray computed tomography(XCT) and micro-Raman spectrometry to measure individual CaCO_3 particle morphology, with sizes ranging from 3.5–6.5 μm. Particle surface area and volume were calculated using a reconstruction method based on software threedimensional(3-D) rendering. The XCT was first validated with high-resolution fieldemission scanning electron microscopy(FE-SEM) to acquire accurate CaCO_3 particle surface area and volume estimates. Our results showed an average difference of only 6.1% in surface area and 3.2% in volume measured either by micro-Raman spectrometry or X-ray tomography. X-ray tomography and FE-SEM can provide more morphological details of individual Ca CO3 particles than micro-Raman spectrometry. This study demonstrated that X-ray computed tomography and micro-Raman spectrometry can precisely measure the surface area, volume, and morphology of an individual particle.     

红壤不同粒级组分中砷的形态——基于连续分级提取和XANES研究

土壤固相由不同大小的土壤颗粒构成.研究砷在土壤不同粒级组分中的形态,有助于深入了解土壤中砷的生物有效性、移动性及其环境风险.本文以砷吸附能力很强的红壤为研究对象,采用传统化学提取法研究了砷在各粒级组分（50～250μm,5～50μm,1～5μm和〈1μm）中的含量和形态,并采用X射线吸收近边结构（XANES）光谱法表征...