一种基于敌手入侵时序图的水域和低空实物保护外部入侵定量评价软件功能模块设计

针对我国现有核设施实物保护定量评价缺少关于水域和低空系统评价的问题,本文提出一种基于敌手入侵时序图（ASD）的水域和低空实物保护外部入侵定量评价软件功能模块设计,通过对现有软件中区域设置的修改,增加水域和低空路径元件的方法,实现对水域和低空实物保护系统的外部入侵定量评价。     

核电仪控系统的网络安全监测

仪表和控制系统作为核电厂"中枢神经"的重要组成部分,对于核电厂安全稳定的运行起到关键的作用。近年来,数字化仪控系统遇到网络安全的新问题,即预防、检测和应对针对仪控系统实施的运用数字化手段的恶意行为。这种网络攻击将致使电厂性能下降,实体设备受损,甚至引发事故工况。依据核电厂"纵深防御"的安全设计理念和国内外法规标准的要求,提出应对核电仪控系统实施网络安全监测。网络安全监测的实施方案为,在仪控系统中部署入侵检测系统,监视并分析仪控系统事件,发现未经授权访问仪控系统资源的尝试并给出报警。本文详细分析了部署入侵检测系统需要考虑的检测点部署位置、监测数据源、入侵检测方法3个方面的问题,并给出了评价方式。     

一种基于关联规则挖掘的入侵检测系统

为解决入侵检测系统普遍存在漏/误报率高、特征库需频繁升级、更新等问题,根据中科院高能所的网络环境,构建了一种基于关联规则挖掘算法的入侵检测系统。该系统可以通过训练数据生成通用的检测规则,并利用规则检测新的攻击。实验证明:该系统对未知攻击具有较好的检测速度和检测率。     

基于信号时频特征的神经网络报警方法

针对在核电站一回路系统中检测金属跌落零件误报警率高的问题，提出了基于信号时频域二维特征的神经网络报警方法；用改进的ＢＰ算法对模拟跌落零件试验的结果进行了处理，表明该报警方法是可行的。     

秦山核电厂松动部件监测系统典型误报警事件分析和处理

松动部件监测系统（LPMS）是核电厂监测一回路中是否有松脱件的基本安全工具,误报警是困扰松动部件监测的一个最重要的问题。为了甄别误报警事件,分析了秦山核电厂运行过程中的典型报警事件数据和工况信息,确认主泵启停过程中的报警、雷雨天气触发的报警、堆顶风机切换触发的报警、主系统在升温升压过程的报警为误报警,并针对这几类典型的误报警给出了解决方案。      

LOCA事故下安全注射系统可靠性的GO-FLOW法分析

反应堆安全注射系统是包含复杂操作时序的动态系统,本文研究了应用GO-FLOW方法对其进行可靠性分析,导出了能将GO-FLOW用于含两种失效模式的可修部件状态概率计算的可靠性参数等效模型,并验证了模型的正确性。给出了实际算例,结果表明,GO-FLOW方法是对含时序问题的动态系统进行可靠性分析的有效工具,本文导出的可靠性参数等效模型提高了GO-FLOW对多状态问题的分析能力。     

基于时序数据挖掘的核电厂故障诊断技术研究

将时序数据挖掘引入核电厂故障诊断,把核电厂的故障诊断当作序列监督学习问题来对待,并采用滑动窗算法将序列监督学习问题转化为经典的监督学习问题.针对反应堆失水事故( LOCA)进行的仿真实验结果表明,在采用滑动窗算法后,诊断精度有一定的提高,再进一步对滑动窗内的时序数据进行特征提取后,诊断精度有了更大的提高,可以解决经典算...     

应用于同步加速器时序控制的片上可编程系统的设计

同步加速器对控制信号的时闻约束要求非常严格,时序控制是加速器控制系统中十分重要的环节.在兰州重离子加速器冷却储存环(HIRFL-CSR)控制系统中,时序控制主要采用FPGA+ARM+linux+DSP的体系结构.本文介绍基于FPGA和uClinux操作系统的片上可编程系统(SOPC)的设计,可将目前ARM+LINUX的工作完全集成在FPGA内实现,省去专用ARM芯片.其最高工作频率可达185 MHz,硬件资源消耗不到4%.片上可编程系统的硬件处理器系统和操作系统都可根据具体需求重新裁剪和配置.SOPC技术在加速器物理以及其他领域有着非常广泛的应用前景.     

用双单稳态实现的单道脉冲幅度甄别电路

针对现行普通单道脉冲幅度分析器的电路较为复杂的问题,在分析研究上下甄别输出脉冲时序逻辑的基础上,提出了利用双单稳态实现单道脉冲幅度甄别的简单、有效、实用的方法,并搭建了电路.实际工作波形表明,该方法可行,电路能够在输入正弦或指数下降脉冲频率高达400 kHz时正常、可靠工作,可应用于核辐射能量测量的幅度甄别.     

松脱部件检测系统在核电站的应用研究

主要研究核电站松脱部件检测系统(LPMS)在出现报警后,如何辨别报警原因系误报警还是出现真实松脱部件,对核电站的安全性和经济效益有重要意义。归纳了引起LPMS报警的原因,提出了确定报警原因的分析方法,总结出了海南核电LPMS报警原因分析步骤;还通过分析国内某核电站报警事件典型处理过程,提出了LPMS系统应用相关的管理建议;对核电站建立、完善LPMS报警分析机制有一定参考意义。     

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.     

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.     

The role of AGFA high-energy CR in the calibration and quality control of multileaf collimators （MLC）

Linear accelerators equipped with multileaf collimators （MLC） are becoming more common and are widely used in the intensity-modulated radiotherapy （IMRT）. There is an imperative need to ensure the commissioning specification of the linear accelerators for the sake of quality assurance （QA） and quality control （QC）. This paper is aimed to investigate the role of AGFA high-energy CR （Computed Radiography） in calibrating dynamic multileaf collimators and evaluating the accuracy of the leaf position. The result shows that AGFA high-energy CR can easily and conveniently be used to calibrate MLC and verify its position. Hence, the application of AGFA high-energy CR is proved to be an accurate and time-saving method for routine MLC QC, especially when MLC calibration adjustments are required.     

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.