某电气股份有限公司X射线探伤检查实时成像系统辐射环境影响评价

对某电气股份有限公司现在用的1台X射线探伤检查实时成像系统进行辐射环境影响评价。对探伤工作场所及周围进行辐射环境质量现状监测,分析辐射事故的影响,并调查公司采取的辐射防护措施以及辐射安全管理状况。结果表明:探伤室防护性能良好,探伤作业不会对周围环境产生明显辐射影响;公司采取的辐射防护措施比较完善,并已形成较为完整的辐射安全管理体系。     

Synthesis of novel CeO2-BiVO4/FAC composites with enhanced visible-light photocatalytic properties

To utilize visible light more effectively in photocatalytic reactions, a fly ash cenosphere （FAC）-supported CeO2-BiV04 （CeO2-BiVO4/FAC） composite photocatalyst was prepared by modified metalorganic decomposition and impregnation methods. The physical and photophysical properties of the composite have been characterized by X-ray diffraction （XRD）, scanning electron microscope （SEM） and energy dispersive X-ray spectroscopy （EDX）, X-ray photoelectron spectroscopy （XPS）, and UV-Visible diffuse reflectance spectra. The XRD patterns exhibited characteristic diffraction peaks of both BiVO4 and Ce02 crystalline phases. The XPS results showed that Ce was present as both Ce4＋ and Ce3＋ oxidation states in Ce02 and dispersed on the surface of BiV04 to constitute a p-n heterojunction composite. The absorption threshold of the CeO2-BiVO4/FAC composite shifted to a longer wavelength in the UV-Vis absorption spectrum compared to the pure Ce02 and pure BiV04. The composites exhibited enhanced photocatalytic activity for Methylene Blue （MB） degradation under visible light irradiation. It was found that the 7.5 wt.% CeO2-BiVO4/FAC composite showed the highest photocatalytic activity for MB dye wastewater treatment.     

核辐射——勿需害怕,但须小心

<正>2011年3月11日下午,日本东部海域发生里氏9.0级大地震,并引发了海啸。位于日本本州岛东部沿海的福岛第一核电站停堆,几个机组发生了失去冷却剂事故。3月12日下午,一号机组发生了爆炸。3月14日,三号机组发生了两次爆炸。这几次爆炸的发生,改写了世界核安全历史,从而又一次触动了老百姓恐"核"的神经。核辐射究竟是什么?核辐射真的很可怕吗?一、人类所受核辐射的来源本文所说的辐射指核电离辐射。人类所受照射的来源主要有两个方面:一个是天然辐射,另一个是人工辐射,其中天     

粉末标准曲线XRF法检测土壤中的重/类金属

建立并验证一种简便、快速、准确、可靠的土壤中7种典型重金属元素(铅、镉、汞、铬、铜、锌、镍)和1种类金属元素(砷)的粉末标准曲线XRF检测方法。研究XRF检测中土壤样品的粒度、密度、样品量、XRF检测参数及干扰效应等的影响,优化XRF检测土壤样品的前处理方法、检测条件和定量标准曲线,以建立土壤样品中铅、镉、汞、铬、砷、铜、锌、镍的XRF检测方法。研究表明,通过选择合适的滤光片,可明显提高XRF检测灵敏度;随着粒度的减小,样品均匀度不断提高,样品密度也随着提高,XRF响应也逐渐下降及稳定,相对标准偏差从1.4%~14.1%降至0.5%~2.0%,最终选择粒度200目的土壤样品4 g,装入样品罐中手动抖实后,进行XRF检测;使用土壤加标样品制作XRF检测定量标准曲线,线性相关系数r20.99,再通过土壤标准样品进行验证、校正,降低不同土壤样品基质对定量产生的影响。所建XRF检测方法与ICP-MS方法检测结果吻合度高,方法稳定性好,方法检测限低(4.5~58.9 mg/kg),其中5种元素满足GB15618-1995中一级限量标准的检测要求。土壤监测结果表明,目标区土壤均符合二级土壤限量标准,其中2个样品符合一级标准,该区土壤环境质量总体较好。     

Removal of arsenate with hydrous ferric oxide coprecipitation：Effect of humic acid

Insights from the adverse effect of humic acid(HA) on arsenate removal with hydrous ferric oxide(HFO) coprecipitation can further our understanding of the fate of As(V) in water treatment process. The motivation of our study is to explore the competitive adsorption mechanisms of humic acid and As(V) on HFO on the molecular scale. Multiple complementary techniques were used including macroscopic adsorption experiments, surface enhanced Raman scattering(SERS), extended X-ray absorption fine structure(EXAFS) spectroscopy, flow-cell attenuated total reflectance Fourier transform infrared(ATR-FTIR) measurement, and charge distribution multisite complexation(CDMUSIC) modeling. The As(V) removal efficiency was reduced from over 95% to about 10% with the increasing HA concentration to 25 times of As(V) mass concentration. The SERS analysis excluded the HA-As(V) complex formation. The EXAFS results indicate that As(V) formed bidentate binuclear surface complexes in the presence of HA as evidenced by an As-Fe distance of 3.26–3.31 ?. The in situ ATR-FTIR measurements show that As(V) replaces surface hydroxyl groups and forms innersphere complex. High concentrations of HA may physically block the surface sites and inhibit the As(V) access. The adsorption of As(V) and HA decreased the point of zero charge of HFO from 7.8 to 5.8 and 6.3, respectively. The CD-MUSIC model described the zeta potential curves and adsorption edges of As(V) and HA reasonably well.     

Graphene-supported nanoscale zero-valent iron：Removal of phosphorus from aqueous solution and mechanistic study

Excess phosphorus from non-point pollution sources is one of the key factors causing eutrophication in many lakes in China,so finding a cost-effective method to remove phosphorus from non-point pollution sources is very important for the health of the aqueous environment. Graphene was selected to support nanoscale zero-valent iron(nZVI)for phosphorus removal from synthetic rainwater runoff in this article. Compared with nZVI supported on other porous materials,graphene-supported nZVI(G-nZVI) could remove phosphorus more efficiently. The amount of nZVI in G-nZVI was an important factor in the removal of phosphorus by G-nZVI,and G-nZVI with 20 wt.% nZVI(20% G-nZVI)could remove phosphorus most efficiently. The nZVI was very stable and could disperse very well on graphene,as characterized by transmission electron microscopy(TEM) and scanning electron microscopy(SEM). X-ray photoelectron spectroscopy(XPS),Fourier Transform infrared spectroscopy(FT-IR) and Raman spectroscopy were used to elucidate the reaction process,and the results indicated that Fe-O-P was formed after phosphorus was adsorbed by G-nZVI. The results obtained from X-ray diffraction(XRD) indicated that the reaction product between nZVI supported on graphene and phosphorus was Fe3(PO4)2·8H2O(Vivianite). It was confirmed that the specific reaction mechanism for the removal of phosphorus with nZVI or G-nZVI was mainly due to chemical reaction between nZVI and phosphorus.     

Characteristics of secondary inorganic aerosol and sulfate species in size-fractionated aerosol particles in Shanghai

Sulfate, nitrate and ammonium(SNA) are the dominant species in secondary inorganic aerosol, and are considered an important factor in regional haze formation. Size-fractionated aerosol particles for a whole year were collected to study the size distribution of SNA as well as their chemical species in Shanghai. SNA mainly accumulated in fine particles and the highest average ratio of SNA to particulate matter(PM) was observed to be 47% in the fine size fraction(0.49–0.95 μm). Higher sulfur oxidation ratio and nitrogen oxidation ratio values were observed in PM of fine size less than 0.95 μm. Ion balance calculations indicated that more secondary sulfate and nitrate would be generated in PM of fine size(0.49–0.95 μm). Sulfur K-edge X-ray absorption near-edge structure(XANES) spectra of typical samples were analyzed. Results revealed that sulfur mainly existed as sulfate with a proportion(atomic basis) more than 73% in all size of PM and even higher at 90% in fine particles. Sulfate mainly existed as(NH4)2SO4 and gypsum in PM of Shanghai. Compared to non-haze days, a dramatic increase of(NH4)2SO4 content was found in fine particles on haze days only, which suggested the promoting impact of(NH4)2SO4 on haze formation. According to the result of air mass backward trajectory analysis, more(NH4)2SO4 would be generated during the periods of air mass stagnation. Based on XANES, analysis of sulfate species in size-fractionated aerosol particles can be an effective way to evaluate the impact of sulfate aerosols on regional haze formation.     

能量色散X射线荧光分析技术在环境空气质量监测中对铅测定的应用

采用EDXRF(能量色散X射线荧光法)测定环境空气中的铅,对监测数据进行了重复性、均匀性、代表性、平行性和准确性方面的分析。实验结果表明,该方法与ICP法测定结果相符,不仅有效可行,而且具有应用推广价值。     

浅谈特种设备制造和检验工作中的X射线辐射防护

介绍了x射线的辐射防护方法，并对x射线检测工作中存在的问题提出了建议。     

石油测井用中子源辐射屏蔽研究

放射源测井技术是当今石油勘探和开发中必不可少的手段，开展对测井人员的屏蔽防护研究十分必要。将聚乙（丙）烯与碳化硼和氧化铝等以不同比例混合后制成的板材和织物具有良好的热中子、中能中子和快中子屏蔽效果，加工成屏蔽装置后，可使镅－铍源中子的屏蔽率达到６２．０６％，γ射线屏蔽率达到３２．４３％，结合中子辐射防护服和防护围裙等的使用，可较好地解决测井人员的辐射防护问题。