Trace Element Determination in Diesel Particulates by Total-Reflection X-Ray Fluorescence Analysis

 Particulate matter of Diesel emissions collected from diluted exhaust during standard test runs with two Diesel fuels of different sulfur content was analysed by total-reflection X-ray fluorescence (TXRF). The trace elements determined were S, Ca, Cr, Mn, Fe, Ni, Cu, Zn and Pb. Additionally, some filter materials were tested with respect to their applicability for sample collection. Quartz fibre filters were found to be most suitable, both from a technical and a chemical point of view. A clear reduction of total particulate emissions during the whole test was observed when the fuel with very low sulfur content was used. In addition, it was found that the wear metal content of particulate matter emitted by a cold engine was higher than that observed during normal engine working temperature. Received September 10, 1998. Revision March 2, 1999     

X-Ray Mapping and Interpretation of Scatter Diagrams

Electron beam induced quantitative X-ray mapping has become a very useful characterisation tool for determining the elemental distribution in materials, whether using energy dispersive spectroscopy or wavelength dispersive spectroscopy. The X-ray intensity distributions of the elements from an X-ray map allow us to generate two dimensional and ternary scatter diagrams thus converting spatial information into concentration dimensions, which is an important tool for displaying the spatial relationships of elements or correlated elements (phases) in materials. To best understand how to use this tool, we need to understand the production and features of the scatter diagram. The type of clustering observed in the scatter diagram, whether oval, linear or spherical, can give the major and trace element distributions within phases as well as qualitative and quantitative phase information. This paper demonstrates the generation of scatter diagrams, properties of scatter diagrams, interpretation of scatter diagrams and the advantages of scatter diagrams through the use of examples.     

Electrically Cooled SiLi Detectors for Application in X-Ray Equipment

The results of the development of electrically cooled SiLi detectors are presented for applications in X-ray equipment. The characteristics of such detectors compare well with those of the detectors cooled by liquid nitrogen, and to obtain these characteristics only 60 W of electric energy is needed instead of liquid nitrogen.     

微量元素与糖尿病

糖尿病是一种常见病。成人糖尿病患病率约为３％,亦即现有糖尿病人达１亿左右。估计到２０１０年,全球糖尿病人将超过２亿。糖尿病的发展涉及多种病理过程,已有令人信服的证据表明,微量元素在胰岛素的生成和作用以及糖尿病人的能量底物代谢中起着极为重要的作用。本文从糖尿病行病学、微量元素在胰岛素代谢中的作用、糖尿病人的微量元素含量变化和糖尿病的微量元素治疗等四个方面综述了微量元素与糖尿病的关系。参考文献７０,表     

Trace Analysis by Heavy Ion Induced X-Ray Emission

 Various K-, L- and M-shell X-ray production cross sections are measured for heavy ion impact on elements in the range Z ₂ = 13 to 83. The ion species range from Z ₁ = 10 to 36, and ion energies from 1 to 16 MeV are used. Enhanced cross sections are observed when the projectile K- or L- binding energy is similar to the energy of the target K-, L- or M-shell. This effect is used to improve the analysis sensitivity for selected elements. As an example trace analysis of Fe in glass with V, Mn, Co and Ni ions is investigated. Results are compared with proton induced X-ray emission analysis on the same samples. In these samples Fe-K_α X-ray production is similar for irradiation with 3 MeV protons and 14 MeV Ni ions. However the signal to background ratio is four times higher for the irradiation with Ni ions as compared to irradiation with protons. Advantages and drawbacks of heavy ion induced X-ray emission for quantitative analysis compared to proton induced X-ray emission analysis are discussed.     

微量元素与病毒性肝炎

微量元素参与机体各种酶及活性物质的代谢，从多方面影响着人的生命过程。肝脏是人体的重要代谢脏器，对微量元素的代谢关系更为密切。病毒性肝炎患者血清硒，锌均明显降低，铜元素高于正常。因此测定患者机体内的微量元素含量，为诊断及治疗提供新的途径和措施，可及时纠正患者体内微量元素的盈缺，有助于改善肝细胞功能及增强机体免疫力。     

小儿佝偻病血中微量元素的观察

对７１例确诊为不同阶段的佝偻病患儿同时进行观察血液中微量元素锌、铜、铅以及血清钙、磷、碱性磷酸酶的变化。结果表明，佝偻病组的血铸、血钙、血磷均低于正常组，血铅、ＡＫＰ高于正常组，血铜则两组无大差异，但铜／锌比值正常组为０．２２±０．６３明显低于佝偻病组０．３６±０．５５，ｔ＝３．２０，Ｐ＜０．０５．各期佝偻病微量元素的变化与正常儿对比，在佝偻病的初期血磷略低于正常，血锌明显减少，碱性磷酸酶升高。在疾病的激期钙、磷、锌明显低于正常，碱性磷酸酶及铅升高，恢复期各元素基本恢复正常。     

微量元素硒与人体健康

从流行病学研究综述了硒与多种疾病、如心血管疾病、肿瘤、白仙障以及糖尿病的关系。硒对这些疾病的治疗机理以及有机硒药物的研制情况。     

Quantitative X-Ray Microanalysis of Heterogeneous Materials Using Monte Carlo Simulations

Monte Carlo simulations are used to obtain new results of x-ray microanalysis of sample types frequently encountered in practical analytical situations such as a vertical layer embedded in a homogeneous matrix and a spherical particulate deposited on a substrate. The simulations show that a 10-nm layer of boron in a steel matrix can be imaged using backscattered electrons and detected using x-ray microanalysis with a field emission scanning electron microscope even with an electron beam energy equals to 20 keV and also that these simulations can be useful to estimate the optimum acceleration voltage to perform such analyses. For a carbon spherical particulate located on the top of a gold substrate, it is shown that x-ray emission and electron backscattering are a strong function of the diameter of the particulate and also of the electron beam energy. Finally, a new method to determine the thickness of a thin film deposited on a substrate is proposed that does not require the measurement of the beam current. That technique can also be used for a spherical particulate deposited on a substrate.     

藏药材白花龙胆花中微量元素的分析

对藏药材白花龙胆花中17种微量元素（Cu、Zn、Fe、Mn、Co、Ni、Se、Cr、Mg、Ca、K、Na、P、As、Hg、Pb、Cd）的含量作了测定。结果表明,白花龙胆花中含有较高的人体必需微量元素和常量元素,其中常量元素K、Ca、Na、Mg和微量元素Zn、Fe、Mn的含量均较高。     

微量元素的生物学作用及其与脂代谢和肥胖的关系

微量元素在脂代谢中有重要作用，阐述了锌、铜、钒、硒等的生物学作用及其与脂代谢和肥胖的关系。     

微量元素锌与癫痫的关系

锌是人体内重要的微量元素，在大脑组织中含量较高。锌与癫痫有关。简要介绍了锌在人体内的分布、代谢、生理功能，并重点综述了锌对癫痫发作产生影响的机制。     

人体微量元素平衡与健康饮食

综述了人体微量元素平衡与健康饮食的关系。微量元素参与机体内的各种代谢,在维持人的生命活动中发挥着重要的作用。正确理解微量元素的生理功能,树立科学的平衡营养观,是引导人们自觉地实现多样化饮食、促进健康长寿的关键。     

肺结核与肺癌病人全血微量元素观察

选取肇庆市第一人民医院传染病区和肿瘤病区的住院病人全血微量元素观察．结核组72例，肺癌组65例．从14种微量元素观察结果中作统计学处理，发现肺癌病人的3种有害元素N1，Cd。Pb对的含量高于肺结核．而Sr与常量元素Ca的含量亦明显高于肺结核．本文认为在肺结核与肺癌的鉴别诊断上能利用微量元素结果的差异提供一早期鉴别诊断途径．同时提示肺结核病人在治疗时应注意补充钙．     

Detector Calibration and Measurement of Fundamental Parameters for X-Ray Spectrometry

Energy-dispersive X-ray spectrometry offers the opportunity for a fast and reliable determination of the composition of a specimen. For fundamental parameter based quantification, detailed knowledge of the X-ray generation cross sections and of the detection system’s efficiency is required. The detection efficiency is determined comparing the measured and calculated spectrum of undispersed synchrotron radiation (SR) from the electron storage ring BESSY II in the spectral range from 0.1 keV to 100 keV. Alternatively, monochromatized SR in the spectral range from 0.1 keV to 60 keV is used to determine the detection efficiency with a typical relative uncertainty of 1% to 2% by direct comparison with a reference detector. Employing well-calibrated detectors and monochromatized SR of well-known radiant power and high spectral purity, fluorescence yields have been investigated and resonant Raman scattering was studied as an example of a basic effect creating spectral background.     

微量元素与妊娠并发症的关系

为探讨孕妇体内微量元素与妊娠并发症的关系,采用回顾性分析的方法,分析了住院分娩有妊娠并发症的孕妇体内微量元素的变化,其中妊高征、胎膜早破、胎儿宫内窘迫、FGR各5 0例,并随机选取同期住院分娩无任何合并症和并发症的孕妇5 0例作为对照组,测定其体内微量元素Zn、Fe、Cu的代谢情况,并探讨其相关性。结果表明,妊高征、胎膜早破、FGR、胎儿宫内窘迫孕妇的静脉血中Zn含量明显低于正常孕妇组,胎膜早破的孕妇血中Cu含量明显低于正常孕妇组(P <0 0 1 ) ,FGR、胎儿宫内窘迫的孕妇血中含Fe量也明显偏低,与正常孕妇组比较,差异有显著性意义。结论是妊娠并发症的出现与孕妇血中的微量元素代谢异常可能有一定的关系     

胃癌与微量元素相关性研究

报道了胃癌患者发中微量元素的变化信息。认为胃癌患者较正常人Zn、Zn/Cu、Mg、Ca均呈显著降低 (P <0 0 5 ) ,胃癌与胃溃疡相比 ,Zn、Zn/Cu、Mg均呈显著降低 (P <0 0 5 )。因此 ,发中微量元素化学信息的变化 ,可作为本地区胃癌的辅助诊断和胃癌与胃溃疡的区别及辅助诊断的依据之一。     

Minor and Trace Element Analysis in Breast Milk Using Inductively Coupled Plasma Mass Spectrometry (ICP-MS)

 Thirty-two breast milk samples provided voluntarily by healthy women living in the Dongting Lake area were investigated by Inductively Coupled Plasma Mass Spectrometry (ICP/MS). Eleven minor and trace elements (Na, Mg, K, Ca, Mn, Fe, Cu, Zn, As, Se and Pb) were quantified and compared with literature reports. The results provide useful data for further studies in the nutritional field. Author for correspondence. E-mail: zhengmh@mail. rcees.ac.cn Received September 4, 2002; accepted February 11, 2003 Published online May 15, 2003     

微量元素与人体健康

讨论了微量元素与人体健康的关系及其在体内的代谢平衡问题,包括：铁的生理功能,硒的免疫功能,铅的毒害作用。     

头发微量元素不平衡与疾病诊断

列出218种与头发微量元素不平衡相关的疾病,其中内科101种、儿科25种、妇产科10种、皮肤科18种、五官科21种、中医科19种、肿瘤科24种。与每种疾病相关的不平衡元素都用箭头表示,箭头向下（↓）表示该元素缺乏,箭头向上（↑）表示该元素过多。某种疾病的发生可能是某种或某些元素缺乏和某种或某些元素过多所引起的,定性地为医生诊断提供了依据。查什么病,需检测什么元素;反之,可从元素检测结果,判别发生什么病。因此,每种疾病需检测相关元素的种数和每种元素的箭头指向具有双重的参考价值。