基于PCI总线的数字化定标器

基于核辐射测量实验和工程项目测试的需要,针对传统NIM结构定标器线路复杂、功能固定且较简单、无法在线控制和数据存储分析等缺点,开发了基于PCI总线的数字化定标器.该数字化定标器采用可编程逻辑电路(FPGA)设计方法,接口采用PCI接口设计.软件采用微软公司的设备开发包(DDK)编写驱动程序,LabWindows/CVI开发定标器的图形化软面板.实验结果表明,该数字定标器精度高,稳定性好,界面直观,操作简单.     

EPICS系统中的网络技术

介绍了实验物理及工业控制系统(Experimental physics and industrial control system,EPICS)基于"标准模型"的分布式控制体系结构、动态数据库及其基于TCP/IP的通道访问协议和构建EPICS控制系统的网络技术策略,描述了一个支持TCP/IP网络设备的通用EPICS设备/驱动器支持程序及其在SSRF二期预研100MeV直线加速器控制系统中的应用.     

利用LabWindows/CVI实现γ能谱的蒙特卡罗模拟

基于蒙特卡罗模拟思想,利用虚拟仪器开发工具LabWindows/CVI编制软件模拟了γ光子在NaI(T1)闪烁晶体中的输运过程.直接以γ光子在NaI(T1)闪烁晶体中的沉积能量近似对应实际γ能谱仪的脉冲幅度输出,从而得到NaI(T1)探测器中γ射线的响应谱线.结果表明,蒙特卡罗模拟得到的能谱能较好地拟合实验测量得到的能谱.     

全自动航空伽玛能谱数据收录系统

介绍了以研华ACP - 4001型号一体化工控机为平台研发的全自动航空伽玛能谱数据收录系统.该系统通过GPS秒脉冲时钟完成全局时钟同步驱动.采用并口完成数据传输,串口获取GPS定位信息,PT100铂电阻温度传感器采集温度值.软件系统基于LabWindows/CVI与VisualC++6.0平台开发,完成数据采集底层动态链接库与友好界面的设计.实验结果表明:收录系统数据收录准确、快速、完整,达到设计目的.     

基于Win32 EPICS输入输出控制器的设计

本文介绍了基于Win32实验物理和工业控制系统(Experimental Physics and Industrial Control System,EPICS)输入输出控制器(Input/Output Controller,IOC)的设计和实现,提出了EPICS IOC和微软技术的衔接方案,结合高性能数字示波器,将基于Win32的IOC很好地融入整个EPICS控制系统.     

实验物理和工业控制系统（EPICS）与LabVIEW接口的应用研究

EPICS(Experimental Physics and Industrial Control System)是一个大型实验物理和加速器控制系统组态软件工具,北京正负电子对撞机重大改造工程(BEPCⅡ)的控制系统,是基于EPICS开发的.在Windows PC机上使用LabVIEW编程,开发采用多种总线形式的前端I/O设备驱动,完成数据采集和数据分析十分方便,已广泛用于测控领域.使用美国散裂中子源开发的共享内存接口,可以将前端的Windows/LabVIEW系统视为既EPICS IOC(Input Output Controller)纳入到职EPICS控制系统,实现数据共享.     

基于PRP协议的EPICS冗余技术

冗余技术是提高EPICS(Experimental Physics and Industrial Control System)在核电领域应用可靠性的有效解决方案。不同于当前采用的"热备用"冗余模式,本文借鉴IEC 62439-3标准所发布的并行冗余协议(Parallel Redundancy Protocol,PRP)阐述的"并行"冗余模式,分析了该协议的应用层实现方案用于EPICS系统的可行性,并参照EPICS的通道访问协议(Channel Access,CA),在Linux系统下开发了基于PRP的EPICS CA协议软件。测试表明,基于PRP应用层协议方案的EPICS CA协议,在网络单点故障时可以实现无缝切换的高可靠性要求,为提高核电领域EPICS系统的通信网络可靠性,提供了实现方式。     

基于ATCA平台的EPICS/IOC冗余技术研究

加速器控制软件EPICS已经在世界各国120多个加速器和实验物理装置上得到了应用,新一代加速器控制系统的EPICS运行平台将从VME转移到ATCA。介绍了在ATCA硬件平台上分别通过Xen和Linux-HA软件中间件进行EPICS/IOC冗余技术研究。     

EPICS下的EtherNet/IP协议的研究

在EPICS下建立了采用EtherNet/IP协议的ControlLogix PLC测试系统,分析了ControlLogix的EtherNet/IP在EPICS环境下驱动程序的实现原理及软件层次结构,解决了现有驱动程序的不足之处,最后进行了ControlLogix EtherNet/IP通讯性能的测试,结果表明它在数据传输的实时性、稳定性、可靠性等方面有良好的性能.     

低能强流离子束装置计算机控制系统

为实现低能强流离子束装置自动化,提高抗干扰能力和稳定度,研究开发了低能强流离子束装置计算机控制系统。该控制系统采用西门子S7 300PLC,下位机使用STEP7V5组态软件进行编程,控制界面用LabWindows/CVI6.0编制,控制位于3个不同电位的离子束系统。文章描述了控制系统的总体结构、硬件选取和软件实现的功能,讨论了系统在调试过程中抑制干扰的方法。     

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.     

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。     

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.     

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.     

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%。     

Assessment of radioactivity levels in some oil samples from the western desert, Egypt

Distributions of natural gamma-emitting radionuclides were determined in 93 oil samples collected from some petroleum fields in the western desert of Egypt. The radioisotope activities in the area under investigation lay in the range of (21 ± 4) to (38 ± 13) Bq?L-1 for 226Ra, (9 ± 2) to (15 ± 5) Bq?L-1 for 232Th, and (154 ± 28) to (303 ± 54) Bq?L-1 for 40K. The mean values were 27, 12, and 201 Bq?L-1, respectively. Among oils, variations in radionuclide ac- tivities could be on account of differences in TDS, HCO3, and Ba, with high or low pH. In this environment, oil prop- erties differently affected the mobilization of natural radionuclides. The range of 226Ra variation had been compared with available data from other countries. The calculated absorbed dose rate ranged from 22.33 to 32.66 nGy?h-1 in lo- cation (B) and (E) respectively, which was less than the accepted value.     

Preparation and properties of 117m Sn(IV)-TTHMP in in-vitro and in small animals

In this work,TTHMP was synthesized and labelled with 117m Sn.The preparation conditions,stability and lipophilicity of 117m Sn(IV)-TTHMP were investigated.Biodistribution of the complex in rabbits and mice was studied.It was found that the quantity of TTHMP and pH value of the prepararion solution had vital effects on the labeling yield of 117m Sn(IV)-TTHMP.It was also found that 117m Sn(IV)-TTHMP was hydrophilic and stable at room temperature and 37℃ in open air 117m Sn(IV)-TTHMP showed unexpectedly high bone uptake and bone-to-blood ratio in the animals.This made it potentially useful as an reagent for skeletal scintigraphy and radiotherapy of bone tumors.     

Gamma radiation levels in the ambient environment of the QNPP Base

Monitoring results of gamma dose rate level in 1992～2004 in the ambient environment of the Qinshan Nuclear Power Plants(QNPP)Base,the northeast of Zhejiang Province,are reported in this paper.It is shown that the gamma dose rate of five monitoring sites of 2.5 km to QNPP Base is 84～113 nGy/h,with an average of 96 nGy/h in the 13 years.The average value is close to the background level of 93 nGy/h prior to operation of the QNPP Base,and is lower than the monitoring result of 101 nGy/h at the reference site in Hangzhou City.Within 50 km from the QNPP Base,the cumulative dose rate of the thermoluminescent dosimeter(TLD)is 90 nGy/h,which is lower than the back- ground level of 111 nGy/h.