反应堆中子注量率和周期测量仪

介绍了所研制的反应堆中子注量率和周期测量仪(用于核电厂核仪表系统中的中间区测量)的主要技术指标,重点阐述了该仪表的功能、工作原理、硬件组成及软件设计情况,并说明了该仪表的特点。该仪表应用了先进的数字技术,采用一个微处理器(8098单片机)进行运算处理,可测得功率值和周期值,并输出所要求的信号。该仪表具有抗干扰能力强、精度     

反应堆中子注量率和周期测量仪

介绍了所研制的反应堆中子注量率和周期测量仪(用于核电厂核仪表系统中的中间区测量)的主要技术指标,重点阐述了该仪表的功能、工作原理、硬件组成及软件设计情况,并说明了该仪表的特点。该仪表应用了先进的数字技术,采用一个微处理器(8098单片机)进行运算处理,可测得功率值和周期值,并输出所要求的信号。该仪表具有抗干扰能力强、精度高、受温度影响小、使用方便等特点。     

西安脉冲反应堆稳态及方波运行核测量仪表研制

西安脉冲反应堆稳态及方波运行核测量仪表在国内原型堆同类仪表的基础上进行了改进与创新。减少了测量设备，并应用数字技术，使仪表可靠性提高，使用维修方便。介绍了该仪表的技术方案、仪表功能、技术特点及仪表的调试和运行情况。     

西安脉冲堆脉冲参数测量装置研制

介绍了我国自主研制的第一套商用脉冲反应堆脉冲参数测量装置（西安脉冲堆脉冲参数测量装置）的设计方案、系统组成、工作原理、技术特点和应用情况。该装置是西安脉冲反应堆主控室控制台的主要仪表之一，具有脉冲参数测量和堆保护功能。装置采用微电子和计算机技术，实现了对反应堆脉冲工况下堆功率变化、脉冲波形与多个参数的实时自动测量与显示，并在功率超限时向反应堆保护系统和报警系统发出信号。文中对装置的工作特性做了描述，并对现场调试和运行情况作了简要介绍。     

核电厂过程仪表系统干扰测试研究和优化改进

针对国内某核电厂执行堆外中子注量率测量通道周期试验异常触发反应堆自动停堆实例,制定了核电厂电气厂房正常照明系统电源对过程仪表系统干扰测试方案。测试方案主要包括:照明灯通断的干扰测试;本组220 V(AC)检修电源箱的干扰测试;220 V(AC)电缆安全距离的干扰测试以及过程仪表机柜接地体系。根据干扰测试结果对反应堆自动停堆事件产生的原因进行分析。改进方案从增大源项距离、屏蔽源项以及接地系统优化3个方面抑制干扰信号,有效消除及降低了信号的干扰幅度。     

西安脉冲堆辐射剂量监测

为了确保反应堆运行人员和公众的安全，西安脉冲堆设置了比较完善的辐射剂量监测系统。该系统包括固定式在线连续监测和便携式仪表及取样监测两部分，本文主要了固定式在线连续监测的监测,测点布置以及各监测仪的性能特点，并简要介绍了便携式仪表及取样监测中各仪表的性能与适用范围。     

基于SCADE的反应堆中子倍增时间算法设计与验证

为实现反应堆装料至升功率期间对核裂变反应速率的密切监视,需对反应堆中子倍增时间进行正确稳定的测量。本文基于对中子注量率测量的统计特性分析,设计了一种适用于压水堆核仪表系统的倍增时间算法,并利用SCADE软件对实现了算法,同时在方家山核电工程2号机组上进行了堆上试验,试验验证了该算法的稳定性、及时性和有效性。因此,本研究设计的反应堆中子倍增时间算法能够应用于压水堆核仪表系统中子注量率测量信号的处理。      

组合式核测量探测器研究

通过合理组合涂硼计数管和γ补偿电离室,在计算机辅助分析和改进涂硼技术的基础上,研制能够覆盖反应堆中子通量的全量程中子核测量探测器。该探测器保持了计数管和电离室的灵敏度,可减少堆外探测孔道和探测器数量,为源区中子测量的准确性和可靠性提供冗余通道,确保反应堆临界安全和核安全。     

岭澳核电站计算堆芯功率的热平衡试验分析

介绍了岭澳核电站反应堆功率运行时,为了保证RPN核功率测量系统反应堆堆芯功率测量的正确,利用KME(试验仪表系统)进行热平衡试验测量核反应堆堆芯功率的方法与计算原理,及其与大亚湾核电站试验测量方法的不同点、技术的改进及存在的问题。     

数字化核测仪表的设计与算法分析

介绍了数字化核测仪表的设计与算法分析，给出了数字化核测仪表的工作原理，以及以单片机为核心的硬件、软件的实现方法、实现准则，以及对反应堆测量的一些算法分析。     

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.     

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.