活性艳蓝染料KNR的辐照降解研究

用Coγ射线辐照活性艳蓝KNR水溶液,研究活性染料的辐照降解特性。以脱色率和化学需氧量COD60(Chemicaloxygendemand)去除率为降解指标,研究了活性艳蓝KNR水溶液在受辐照前后的紫外可见光谱变化,并探讨了吸收剂量、H2O2加入量、初始浓度、溶液pH值和溶液在不同气体饱和下对降解效果的影响。结果表明,辐射技术能有效降解活性艳蓝染料,脱色效果十分理想,COD去除率可达80%以上。     

γ辐射降解高浓度氨氮条件下苯酚的研究

采用60 Coγ射线辐射降解苯酚,通过分析辐照前后苯酚去除率与化学需氧量(COD)的变化,研究了苯酚浓度、氨氮质量浓度、吸收剂量、初始pH值和自由基清除剂对苯酚的辐射降解效果的影响。结果表明:γ辐射技术能有效降解高浓度氨氮环境中的苯酚,苯酚及其COD去除率随着吸收剂量的增加而增大,苯酚的辐射降解符合准一级动力学方程;吸收剂量相同时,苯酚初始浓度越高,苯酚去除率越低;氨氮质量浓度对γ辐射去除水溶液中苯酚未见显著影响,辐照前后氨氮质量浓度变化不大;弱酸性条件更利于溶液中苯酚的去除;苯酚的辐射降解机理以·OH氧化为主。     

茜素红的辐射降解研究

用60Co γ射线辐照茜素红水溶液,研究该染料的辐射降解特性.通过对辐照前后茜素红的紫外可见光谱、脱色率、总有机碳(Total organic carbon,TOC)去除率的研究.探讨了吸收剂量、初始浓度、溶液pH值、H2O2加入量、在不同气体饱和条件下对茜素红溶液降解和矿化效果的影响.结果表明,辐射技术能有效降解茜素红染料,在空气饱和双氧水浓度为4mmol/L的条件下,吸收剂量为7.5kGy时,茜素红脱色率可达98%,TOC去除率可达70%.     

对硝基苯胺的辐照降解研究

采用电子束辐照对硝基苯胺水溶液,研究了对硝基苯胺的辐照降解过程,并对吸收剂量、初始浓度、溶液pH及H202加入等因素对辐照降解效果的影响进行了探讨。结果表明,电子束辐照能够有效地降解对硝基苯胺。初始浓度为100mg／L,吸收剂量为20kGy时,对硝基苯胺的降解率可达95％以上,化学需氧量（Chemical oxygen demand,COD）的去除率可达41％以上。     

电子束辐照处理水溶液中的活性染料

印染废水是我国工业废水的主要品种之一,如何有效处理印染废水是当今一个重要的研究课题。本文选择两种活性染料为处理对象,研究其在电子束辐照下的降解和脱色。通过染料水溶液受到辐照前后的紫外可见光谱的分析,以及化学需氧量、吸光度和溶液pH值的变化,研究其辐射降解脱色特性。同时研究了过氧化氢对染料辐射降解的协同作用。结果显示利用辐射技术处理印染废水具有相当好的应用前景。     

4–氯酚的γ射线辐照降解研究

利用 Co γ射线(2.2—14.9kGy)辐照 4-氯酚水溶液,研究了其辐照降解特性。通过对辐照前后 4-氯 60酚的紫外可见光谱、有机氯脱除率、化学需氧量(Chemical oxygen demand, COD)去除率的研究,探讨了吸收剂量、H2O2加入量、初始浓度、溶液 pH 值对降解效果的影响。结果表明,这一辐射技术能有效降解 4-氯酚,有机氯脱除率可达 100%,COD 去除率可达 65.8%。     

4-氯酚的γ射线辐照降解研究

利用^60Coγ射线(2．2—14．9kGy)辐照4-氯酚水溶液，研究了其辐照降解特性。通过对辐照前后4-氯酚的紫外可见光谱、有机氯脱除率、化学需氧量(Chemical oxygen demand,COD)去除率的研究，探讨了吸收剂量、H2O2加入量、初始浓度、溶液pH值对降解效果的影响。结果表明，这一辐射技术能有效降解4-氯酚，有机氯脱除率可达100％，COD去除率可达65．8％。     

~(60)Co γ射线辐照五种常见渔药在水溶液中降解作用的研究

本文采用0—10kGy的60Coγ射线对水溶液中的磺胺二甲基嘧啶、噁喹酸、氯霉素、呋喃唑酮、土霉素进行处理,并测定了环境的酸碱性、空气、温度对辐照降解率的影响。结果表明,60Coγ射线辐照处理能显著降解五种常见渔药在水中的残留,吸收剂量越大,渔药的降解率越高;初始浓度越低,越有利于渔药的去除。当吸收剂量为8kGy时,五种渔药(初始浓度100mg/L)的降解率均达到90%以上,酸碱性和空气环境对不同种类的渔药降解率影响有一定的差异,降低温度对渔药降解有明显抑制作用。     

甲基橙溶液的辐射降解研究

以60Coγ射线为辐射源,对偶氮染料甲基橙进行了γ射线辐射降解研究,探讨了H2O2加入量、吸收剂量、初始浓度和溶液pH值对辐射降解结果的影响。结果表明,γ射线辐射能有效降解甲基橙,化学需氧量(CoD)去除率可达80％以上,脱色效果显著。H2O2加入量、吸收剂量、初始浓度均与甲基橙的降解效率有关,而溶液的pH值对降解影响不大。实验证实,利用γ射线辐射降解技术处理染料废水是一种可行的方案。     

伽玛射线辐照降解水溶液中土霉素及其降解路径的研究

探索了γ-射线辐照降解土霉素(Oxytetracycline,OTC)的高效、无二次污染的方法,研究了γ-射线吸收剂量、OTC溶液初始浓度(C0)和p H值对辐照降解效率的影响。结果表明,吸收剂量越高、OTC溶液初始浓度越低、p H值越低,则OTC降解率越高。采用液相色谱质谱联用仪检测到m/z为447、443、433、279和218的降解产物,结合量化计算OTC及其中间产物能量、键级性质、自然布居分析提出两条OTC降解路径。路径一首先降解N(27)和C(10)上的甲基,之后在C(12)-C(15)、C(13)-C(18)处断裂生成m/z为279的产物,最后于C(10)处脱水生成m/z为261的物质;路径二首先发生脱水和结构重排,其后从C(13)-C(14)处断裂生成m/z为230的稠环产物,最后碳氧杂环降解掉CH2和羧酸基团。质谱检测降解产物并结合量化计算解释能高效准确地提出OTC的γ-射线辐照降解路径。     

Identification of radiation treatment of wheat （Triticum aestivum. L）and rice （Oryza sativa. L） samples using thermoluminescence of contaminating minerals

Food irradiation is gaining popularity worldwide and this technology is important to improve quality and reduce the post harvest losses of food. Because of the rapid commercialization of irradiated foods throughout the world, compliance of different regulations relating to use of technology in different countries and demand of consumers for clear labelling of irradiated foods, there is need for the development of analytical methods to detect radiation treatment of food. Among several methods studied so far, thermoluminescence （TL） is an important method that can be used to find out the irradiation history of food that contain even a very minute amount of dust particles. In this study, the irradiated and unirradiated wheat and rice samples were analyzed using the TL method. The samples were purchased from the local market of Peshawar and irradiated to radiation doses of 0.5 and 1.0 kGy using Co-60 gamma irradiator at the Nuclear Institute for Food and Agriculture （NIFA）, Peshawar. The mineral contaminants were isolated by jet water, ultrasonic treatment, and density gradient. TL glow curves of the isolated minerals from irradiated and unirradiated samples were recorded between the temperature ranges of 50-500℃ using a TL reader. Generally, the glow curves for irradiated samples showed much higher TL intensities （TL1） than the unirradiated samples. The results were normalized by rerradiation of mineral samples to gamma-ray dose of 1.0 kGy followed by determination of the second glow curves （TL2）. The ratio of the area of first glow curve to that of second glow curve （TL1/TL2） was calculated for selected temperature intervals and compared with the recommended values for unirradiated and irradiated samples. Finally, the shapes of the glow curves for irradiated and unirradiated samples were also analyzed. On the basis of these results （comparison of TL-intensities, TL1/TL2 ratios and shapes of the glow curves）, all the irradiated and unirradiated samples of wheat and rice were unequivocally identified.     

The preclinical pharmacological study of dopamine transporter imaging agent 18F-FP-β-CIT

The paper is to study pharmacologic characteristics of 18F-FP-β-CIT (18F-N-(3-fluoropropyl)-2β- carbomethoxy-3β- (4-iodophenyl)nortropane) as an imaging agent for dopamine transporter. The radiochemical purity of 18F-FP-β-CIT in aqueous solution was over 95% after standing at room temperature for 4h. Biodistribution displayed rapid uptake in rat brain (1.375 %ID/organ at 5min and 0.100 %ID/organ at 180 min) and the striatal uptake was 1.444,0.731, 0.397, 0.230 and 0.146 %ID/g at 5, 30, 60, 120 and 180 min, respectively. The values of striatum/cerebellum,striatum/frontal cortex and striatum / hippocampus in rat's brain at 30 min were 3.38, 2.17 and 2.40 respectively. The uptake in striatum can be blocked by β-CFT, suggesting that 18F-FP-β-CIT binds to DAT peculiarly. The compound was rapidly cleared from monkey's blood. The striatal uptake was bilaterally decreased in the left-sided lesioned PD rats, compared with normal control. Brain PET imaging studies in normal monkey showed that 18F-FP-β-CIT was concentrated in striatum. The test of undue toxicity showed that the dose received by mice was 1250 times as by human, which indicates that 18F-FP-β-CIT is very safe. So 18F-FP-β-CIT is a promising PET imaging agent for DAT with safety and validity.     

PLASMA SCIENCE AND TECHNOLOGY AUTHOR INDEX TO VOLUME 16(2014)

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Radioactivity levels in soil of salt field area,Kelambakkam,Tamilnadu,India

Soil samples in and around salt field area have been analyzed for natural radioactivity concentration using gamma ray spectrometer.The activity concentration for ~(232)Th,~(238)U and ~(40)K are ranged from 27.88 to 45.27 Bq/kg, from BDL to 13.30 Bq/kg,and from 135.54 to 381.28 Bq/kg,respectively.The measured activity concentrations for these radionuclides were compared with world average activity of soil.The average activity concentration of ~(232)Th in the present study is 1.19 times higher than world median value while the activity of ~(238)U and ~(40)K is found to be lower. The absorbed dose rates due to these radionuclides were calculated.The average absorbed gamma dose rate due to the presence of ~(232)Th,~(238)U and ~(40)K in soil samples is 36.99 nGy·h~(-1).These results indicate no radiological anomaly. The data presented in this study will serve as a base line survey for primordial radionuclides concentration in the study area.     

Non-FDG PET imaging of brain tumors

Due to relatively high uptake of glucose in the brain cortex, the use of FDG PET imaging is greatly limited in brain tumor imaging, especially for low-grade gliomas and some metastatic tumours. More and more tracers with higher specificity were developed lately for brain tumor imaging. There are 3 main types of non-FDG PET tracers： amino acid tracers, choline tracers and nucleic acid tracers. These tracers are now widely applied in many aspects of brain tumor imaging. This article summarized the general use of non-FDG PET in different aspects of brain tumor imaging.     

基于NPL-NMC系统的γ测量子系统的建模与优化

在军控核查中,核部件的质量、丰度、年龄属性需采用无损方法进行核查,NPL-NMC系统是一套利用中子多重性测量核部件质量属性的装置,为建立完善的属性测量系统,还需在NPL-NMC系统的基础上建立γ测量子系统。本文通过设计γ测量子系统在NPL-NMC系统上的布局及对中子屏蔽的优化,使系统能对铀部件的丰度、年龄属性进行测量。模拟计算结果表明,该γ测量子系统能很好地满足军控核查对铀部件丰度、年龄属性测量的要求。     

Improvement of carbon fiber surface properties using electron beam irradiation

Carbon fiber-reinforced advance composites have been used for structural applications,mainly on account of their mechanical properties.The main factor for a good mechanical performance of carbon fiber-reinforced com- posite is the interfacial interaction between its components,which are carbon fiber and polymeric matrix.The aim of this study is to improve the surface properties of the carbon fiber using ionizing radiation from an electron beam to obtain better adhesion properties in the resultant composite.EB radiation was applied on the carbon fiber itself before preparing test specimens for the mechanical tests.Experimental results showed that EB irradiation improved the ten- sile strength of carbon fiber samples.The maximum value in tensile strength was reached using doses of about 250 kGy.After breakage,the morphology aspect of the tensile specimens prepared with irradiated and non-irradiated car- bon fibers were evaluated.SEM micrographs showed modifications on the carbon fiber surface.     

Measurement system for SSRF pulsed magnets

This paper describes the magnetic field measurement system for pulsed magnets in SSRF.The system consists of magnetic probes,analog active integrator,oscilloscope,stepper motor and a controller.An application pro- gram based on LabVIEW has been developed as main control unit.After the magnetic field mapping of a septum magnet prototype,it is verified that the test results accord with the results of theoretical calculation and computer simulation.     

旁路阀调节对高温气冷堆闭式布雷顿循环瞬态特性影响研究

闭式布雷顿循环是第4代高温堆核能系统的关键技术之一,其典型的动态过程是旁路阀调节。为分析这一过程,建立了循环中关键部件的动态模型,其中压气机在径向平衡模型基础上耦合了对附面层发展的预测,兼顾了计算效率与准确性;换热部件模型基于双曲型守恒律方程,对工质的热物性和参数的快速变化有较好的适应性。在此基础上根据回路的质量守恒和压力平衡原则将各部件的模型耦合,建立了系统的动态模型。由于旁路阀调节是氦气透平发电系统主要的功率快速调节手段,瞬态效应较为显著,以模块式高温气冷堆（HTR-10GT）旁路阀开启后的过渡过程作为算例,分析了主要循环参数的响应特性,并通过分析,给出了降低输出功率的机制。计算结果表明：系统的容积惯性对旁路阀调节的响应速度影响较大,而阀门的开度则决定了系统在末态的输出功率;回热器的温度冲击现象可能发生在调节过程中,但可通过两旁路阀联动的方式缓解;反应堆出口温度变化幅度很小,因此反应堆模型的准确程度对结果基本无影响。     

CEFR 100%额定功率运行汽轮机发电能力分析

中国实验快堆(CEFR)首次100%额定功率发电运行中,实际电功率较设计值相差较多。为判断影响机组实际发电能力的主要原因,以现场采集的运行数据和汽轮机厂商提供的设计资料为基础,进行了相应的计算分析。对汽轮机内效率进行修正,绘制汽轮机近似热力过程曲线,并通过实测的各段抽汽压力,在热力过程曲线上获得抽汽焓值;利用换热器的能量守恒和流量守恒的基本方程进行除氧器和各加热器的热平衡计算,获得各段抽汽的流量;利用汽轮机的功率计算方程,得到汽轮机发电功率的计算值。通过计算值与实际值的比较分析,得出主蒸汽参数不达标是影响CEFR汽轮机发电能力的主要因素。