基于EAST装置上液态调配器系统的研究

液态调配器是用于离子回旋共振加热系统以代替传统活塞式调配器的一种新型阻抗匹配装置。通过对液态调配器工作原理的研究,设计了液态调配器的油路系统,采用计算机和可编程控制器对系统进行控制。同时,对液态调配器各支节匹配高度的计算方法进行了研究,提出了计算公式,并利用实验中测得的数据对计算公式进行了验证。经过两轮EAST实验使用证实,该系统完全满足设计要求。     

三支节液态调配器ICRH时的阻抗匹配分析

基于传输线理论,采用三支节液态调配器以达到托卡马克离子回旋共振加热(ICRH)时射频源和天线负载间的阻抗匹配。分析了其阻抗匹配过程,并根据阻抗匹配条件得到天线输入阻抗变化时,三支节液态调配器的优化调配参数。利用数值模拟验证了在其他实验参数相同的条件下,三支节液态调配器的优化调配参数能使天线系统获得良好的匹配状态。     

ICRF功率传输系统中预匹配支节设计

在EAST装置内离子回旋共振加热(ICRF)系统中,天线与液态调配器之间传输线上的驻波电压幅值会因为负载阻抗的变化而变得很大,为此设计了ICRF功率传输预匹配支节。本设计采用解析法和Smith圆图法相结合的分析方式,在ICRF系统中安装了预匹配支节,并对其降压效果进行了测试。测试结果表明,安装预匹配支节之后,预匹配支节与液态调配器之间传输线上的驻波电压幅值得到有效降低,可作为优化ICRF功率传输系统功率传输性能的候选者。     

基于Labview的XAFS光束线实验站数据采集系统

本文介绍应用Labview软件、气体电离室、电流放大器及数据采集卡等仪器设备构成的同步辐射XAFS(X-ray absorption fine structure)光束线站(BL14W1)数据采集系统.该系统利用NI公司开发的新模块DSC module(Datalogging and Supervisory Control Module),实现了在Labview和EPICS(Experimental and Physics Industrial Control System)两个软件系统间数据的快速交换,使光束线控制的标准化和实验站用途的多样化有机结合.用Labview编写了数据采集软件,使该线站成功实现步进(step-by-step)模式和快扫(QXAFS)模式下的XAFS谱的采集.     

反应堆互功率谱密度测试系统设计

设计了一种基于PXI-1031高速同步数据采集卡(DAO)的虚拟仪器硬件测试系统.利用Labview8.5程序设计出了测试系统所需的数据采集和数据处理分析程序.使用Fluke-282任意波形发生器产生两路频率分别为150 Hz和270 Hz的正弦信号,应用数据处理分析程序完成了两路信号的互功率谱密度计算.仿真试验结果表明,测试系统达到了设计要求.     

10 MeV辐照电子直线加速器控制系统

本工作为1台10 MeV辐照用电子直线加速器研制控制系统。该控制系统采用分布式网络控制,由多个子系统构成。硬件采用SIEMENS PLC芯片和监控计算机,PLC间采用PROFIBUS、MPI等高速总线进行连接,与监控计算机采用以太网连接,使用TCP/IP协议,能在互联网上远程监视和维护,进行网络控制。软件采用STEP 7和C语言等编写,对各子系统及子系统间连接均采用独立的数据块和功能函数块。部分硬件功能由软件来实现,使得整个系统更易于测试、制造和维护升级。     

自屏蔽式电子束消毒灭菌装置控制系统

研制了由程序逻辑控制器(PLC)和监控计算机构成的自屏蔽式电子束消毒灭菌装置分布式网络控制系统。在友好计算机界面下，操纵人员能控制整个系统，并能在互联网上远程监视和维护，从而实现网络监控。软件采用CXP和C语言等编写。部分硬件功能由软件实现，使得整个系统更易于测试、生产和维护升级。     

基于LabVIEW的PREKY回路测控系统的设计与实现

针对FDS团队建造的PREKY液态高温铅铋回路测控系统的需求,在Lab VIEW2009开发环境下,利用PXI系列数据采集卡实现了对回路温度、压力和液位信号的实时测量,并由上位机完成对实验数据的在线分析和保存。同时,利用虚拟仪器技术研制了一套具备远程监控、故障诊断和报警功能的液态铅铋回路测控系统,并对回路电磁泵出口压力测量结果进行了误差分析。     

中国实验快堆三回路计算机监控系统系统结构可靠性设计改造

中国实验快堆三回路计算机监控系统承担着三回路的系统状态监视及设备控制等任务。由于三回路监控系统开发公司在系统还未移交给快堆工程部时期出现了公司易主重组等情况,系统的后期开发及调试工作一直由一名公司代表负责,系统实际并未达到设计的使用要求。在公司代表离开后,系统已经处于临近瘫痪的状态,无法完成正常的监控功能,严重影响反应堆的运行任务,因此对三回路计算机监控系统进行了重新设计及改造。文中通过列出存在的各种异常现象,并进行分析排查,找出异常现象的根源问题,对这些问题按照系统结构及功能进行分类找出需改造的类项。对每一项详细介绍了设计思路及具体改造步骤,针对改造中遇到新问题的处理方法作了适当的介绍。通过系统性的改造使三回路计算机监控系统具备了正常的监控功能,并通过对底层结构进行的冗余改造从本质上提高了系统的可靠性及运行稳定性。改造完全由快堆内部的技术人员完成,由此培养了一支有实际工程开发经验的人才队伍,同时节省了数十万的外协开发费用,并通过合理设计利用老硬件节省了几十万元的硬件采购费用。对监控系统重新进行的设计改造为中国实验快堆顺利100%功率并网发电及今后的运行提供了有力的保障,并为今后的全厂级监控系统改造奠定了良好的基础。     

BSRF光束线水连锁集中监控系统

介绍了基于SCADA系统的BSRF(北京同步辐射装置)光束线水连锁集中监控系统.该系统对光束线冷却水状态进行实时监控,及时发现故障并给出报警,以保障光束线设备安全、稳定、可靠地运行.系统底层通过PLC对现场设备进行数据采集及连锁控制,系统上层采用工控组态软件-力控,实现人机界面编写、故障报警、历史数据记录和网络发布.该...     

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.     

有效探测面积大于1000 cm2的正比计数器测量系统性能测试

为对自制的活性面积高达1 000 cm²的大面积源进行表面发射率定值,同时作为现有2πα、2πβ表面发射率标准装置能力的扩充,研制了一套内置式大面积2π多丝正比计数器测量系统,并利用活性区直径为8 mm的²⁴¹Am点源及活性区面积为10 cm×15 cm的大面积²⁴¹Am和⁹⁰Sr-⁹⁰Y源对其进行计量学性能测试。结果表明：计数器内计数响应均匀性优于±0.4%,有效探测面积达1 400 cm²;所得²⁴¹Am源高压坪曲线的坪长为1 400 V,坪斜为0.27%/100 V,坪区内计数变化为0.87%;⁹⁰Sr-⁹⁰Y源高压坪曲线的坪长为300 V,坪斜为0.75%/100 V,坪区内计数变化为0.80%;10次测量重复性好于0.4%,8 h内短期稳定性好于0.3%,1 a内长期稳定性好于0.8%。     

Preparation of Zn/TiO2 powder and its photocatalytic performance for oxidation of P-nitrophenol

Zn-doped TiO2 catalysts were prepared using a sol-gel method and characterized by XPS,UV-Vis, BET, XRD in this study. Under the irradiation of simulant sunlight, the photocatalytic activity for the degradation of p-nitrophenol was studied too. After irradiation for 2.5 h, the degradation percentage of p-nitrophenol could rise to more than 80 %. The results showed that the spectrum absorption band edge of Zn/TiO2 powder does not broaden obviously comparing with pure TiO2 powder. Zinc exists as Zn （11）. When calcined at 973 K, there is a new phase as ZnTiO3 in Zn/TiO2 catalyst. The order of photocatalytic activity of Zn/TiO2 catalysts calcined at different temperatures for p-nitrophenol is 773 K 〉 673 K 〉 873 K 〉 573 K 〉 973 K and the photocatalytic activity of Zn/TiO2 catalyst calcined at 773 K is better than TiO2 catalysts heated at the same temperature, and outclasses that of commercial TiO2 catalyst. It also showed that the photocatalytic degradation of p-nitrophenol follows first-order kinetics under the irradiation of simulant sunlight.     

Current status of radiation therapy for prostate cancer

Radiotherapy for the treatment of prostate cancer has been extensively explored in the past. Along with the comprehensive understanding of the biology of prostate cancer and rapid advances in terms of technology, the out- come of treatment for the patients with prostate cancer has improved. The authors review radiotherapy as the primary treatment for the disease, with particular emphasis on the technological advances from both the radiobiological and radiophysics aspects. Nonconventional fractionated irradiation like hyper- or hypo-fractionation has been imple- mented in the clinic, the final results still need to be confirmed in the future. Technological advances like IMRT, IGRT, in the last two decades have significantly improved the delivery of external radiotherapy to the prostate. This has re- sulted in an overall increase in the total dose that can be safely delivered to the prostate, which has led to modest im- provements in the biochemical outcome. However, establishing the standard therapy for prostate cancer remains con- troversial. It is hoped that the next decades will bring continued advances in the development of biologicals that will further improve current clinical outcomes.     

The control system for SSRF injection and extraction

This paper introduces the injection and extraction control system design for SSRF,which is a distributed control system aimed at stability and reliability of the pulse power supplies,PPS(Personnel Protection System)and MPS(Machine Protection System).The hardware environment is mainly based on PLC(Programmable Logic Con- troller),and ARM(Advanced RISC Machine)is also applied for studying stability of the power supplies.WinCC and EPICS(Experimental Physics and Industrial Control System)have been selected as the platforms of SCADA(Super- visory Control and Data Acquisition).For unifying the interfacing to the control computer,all front-end equipments are connected via Industrial Ethemet.     

Interaction between uranium and humic acid (Ⅰ): Adsorption behaviors of U(Ⅵ) in soil humic acids

The adsorption behaviors of uranium on three soil humic acids (HAs), which were extracted from soils of different depths at the same site, were investigated under various experimental conditions. The adsorption results showed that U(Ⅵ) in solutions can be adsorbed by the three soil HAs, with the order of FHA (HA from 5 m depth of soil) ＞SHA (HA from the surface) ＞THA (HA from 10 m depth of soil) for adsorption efficiency in each desirable condition, and the adsorption reached equilibrium in about 240 min. Although the maximum adsorption efficiency was adsorption could be described with Langmiur isotherm or Freundlich isotherm equation. The L/S (liquid/solid, mL/g)ratio and pH were important factors influencing the adsorption in our adsorption system besides uranium concentration. The adsorption efficiency decreased with the increase of the L/S ratio and pH at the pH range of 2.0-3.0 for SHA and THA or 2.5 - 6.0 for FHA. However, no significant difference in adsorption of U(Ⅵ) was observed at the experimental temperature. All the results implied that humic substances have different characteristics in samples even collected at the same site.     

水平管内含空气蒸汽强制对流冷凝换热模型研究

为研究含空气蒸汽在水平管内强制对流冷凝换热特性,基于对传热传质过程的分析,建立了管内为环状流与波状流条件下的流动冷凝换热模型。从潜热、显热和液膜3个环节对整个换热过程进行建模,最终得到计算局部冷凝换热系数的理论关系式。模型预测结果与实验数据的对比表明,二者相对偏差在±20%以内,验证了该换热模型的准确性与适用性。通过进一步的研究发现：从换热管入口至出口,随着冷凝的进行,管内换热主要热阻由液膜热阻向气液界面的凝结热阻转变;主流气体对流换热过程基本可忽略。     

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.     

Web Services interface of SSRF archive data analysis system

Accelerator database stores various static parameters and real-time data of accelerator. SSRF (Shanghai Synchrotron Radiation Facility) adopts relational database to save the data. We developed a data retrieval system based on XML Web Services for accessing the archive data. It includes a bottom layer interface and an interface applicable for accelerator physics. Client samples exemplifying how to consume the interface are given. The users can browse, retrieve and plot data by the client samples. Also, we give a method to test its stability. The test result and performance are described.     

Investigations on landmine detection by BF3 detector

Experiments were carried out to investigate the possible use of neutron backscattering for the detection of polyethylene (PE) sample buried in the soil. In detection of landmine by neutrons, the neutron detector and its shield play an important role. In this paper, the effects of graphite, heavy water, polyethylene and boric acid moderators on the flux of back scattered neutrons were investigated. We have also experimentally verified the effect of BF3 detector shield and obtained good agreement with theory.