基于以太网传输的高速32通道数据采集系统

本文介绍了一种基于以太网传输的32路高速数据采集系统,该系统主要用于核燃料棒质量检测中,可以对核燃料棒检测传感器发送的数据进行采集和分析。该系统包括数据接收模块、系统控制模块、网络通信模块和上位机数据分析控制软件四个部分。系统使用FPGA来进行数据的接收和计数,使用ARM作为整个系统的主控芯片来控制各个模块之间协调运行,同时利用ARM对数据进行组包并将组包后的数据通过以太网传输到上位机,最后由上位机对数据采集装置上传的数据进行接收和处理。经测试证明系统工作稳定,可以达到工业检测要求。     

高速多通道Υ射线工业CT数据采集系统

为满足Υ射线工业CT的高速多通道数据采集要求,设计了针对性的高速数据采集系统实现数据的采集和处理.Υ射线转换为放大的电流信号后,经信号处理电路进行放大、甄别、分频处理,然后信号经FPGA计数单元整理后传送到主控FPGA.主控FPGA作为控制核心,对配置为Slave FIFO工作模式的USB2.0内部的FIF0进行控制,...     

基于FPGA的高速以太网流量发生器

采用高速以太网作为通信介质的高速传感器网络的开发过程中需要对节点的诸如自定义协议的正确性、吞吐能力、丢包率等指标进行测试.。用软件产生以太网流量存在精确性不足等问题,因此需要一款硬件平台产生可自由配置任意格式、长度、帧间隔、填充模式的高速以太网帧流量,以满足系统测试的需要。基于FPGA可以实现这样一个帧发生器,它与传统的逐层封包不同,创造性地采用了与数据并行置入的填充类型选择域作为配置数据,满足了灵活填充的要求。这样的结构具有高速性、灵活性和可扩展性,可全线速产生千兆或百兆以太网帧流量。     

基于CAN总线的楼宇智能监控报警系统研究与设计

介绍了一种基于CAN总线的智能多路监控报警系统的设计方法.在信息传输的安全性、准确性、实时性方面达到了较高要求.本系统利用AT89C51单片机对多路监测信号进行采集和处理,并控制CAN总线控制器SJA1000/收发器PCA82C250构成的CAN总线通信系统进行数据传输,通过串行接口MAX232将主控机与各控制节点相联,实时监控各设备状态,并可实现监控方案下载更新.文章介绍了系统工作流程及主要功能模块设计原理.通过实验,监测报警率可达100%,有效地实现了楼宇智能监控报警.系统提供了较好的硬件平台,方便移植智能算法,以满足更多监控需要,具有良好的应用前景.文章详细介绍了系统总体设计方案,部分软硬件设计方法.     

中性束注入器多通道远程真空测量系统设计

为满足中性束注入器多点、远程真空监测的需要,设计了基于STM32的多通道远程真空测量系统。该系统采用规管传感器测量得到真空室的真空度电压信号,采样芯片ADS1256测量经信号调理电路调理后的规管电压信号,以STM32F103ZET6作为主控芯片,结合模数转换电路、基准电压产生电路及其他电路,将处理后的数据由以太网传输到上位机,利用上位机软件实现对中性束注入器真空状态的实时监测、预警和分析。测试结果表明:该系统稳定有效运行,适用于中性束注入器真空度测量。     

CH4气体浓度分布式监控系统研究与设计

针对热催化元件检测方式精度较低、检测范围窄,对高浓度瓦斯气体(CH4)检测会得到致命错误信息的弊端,本系统利用红外瓦斯气体传感实现CH4浓度信号采集,通过运算放大、采样保持、A/D转换后,送入单片机进行处理,并控制现场通风设备等工作,保证煤矿瓦斯浓度值在规定范围以内,以避免事故的发生.另外,系统通过CAN总线将监控装置连接,主控PC机通过RS232及CAN总线通信模块与CAN总线连接实现了工作现场实时监控、数据分析与处理.文章对系统硬件设计及部分软件流程进行了描述.通过实验测试,系统通信良好,浓度检测精度不大于±0.2%,检测线性度好、稳定时间较快,且室温下漂移误差较小.     

基于CAN总线安全监测控制系统研究与设计

为实现对生产制造企业设备操作人员危险工作区安全防护,设计了一种基于CAN总线技术实现分布式安全监控防护系统.系统借助红外传感器光电转换特性,利用AT89C51单片机对检测信号进行处理,并控制CAN总线控制器SJA1000/收发器PCA82C250构成的CAN总线通信系统进行数据传输,通过串行接口MAX232将主控机与各控制节点相联,实时监控各设备状态,并可实现监控方案下载更新.文章介绍了系统工作流程及主要功能模块设计原理.通过实验检测,系统控制精度可达0.1mm,保护距离可达15m,检测正确率100%.另外,本系统对FA431粗纱机进行设备改造,有效实现了断纱、断条及纱线在线质量检测,生产效率提高25%-35%.     

用于螺旋CT的数据采集设计方案

对于工业螺旋CT的应用,针对其实时性、数据量大的特点,提出了数据采集系统的设计和实现方法.采用双CPU的系统的设计,一块负责用DMA的方式把CT数据从前置放大器传送到FIFO,另一块负责将FIFO中的数据通过无线网络传送到主控站进行进一步处理.该设计已在现有工业CT中得到应用.     

基于CAN总线和以太网的嵌入式环境辐射监测系统设计

为实现客户对环境辐射监测数据的远程查询和监视,设计了基于CAN总线和以太网络的嵌入式环境辐射监测系统。该系统以ARNM微处理器为核心,利用CAN总线的优势性能,有效地提高了环境监测数据传输的可靠性和安全性。并采用嵌入式数据库和WEB体系结构,结合表单和CGI技术,将CAN总线采集到的数据进行管理和分享,实现了客户和嵌入式环境辐射系统的动态交互。     

基于千兆以太网的多通道高速数据采集系统

为了快速检测核燃料棒的质量是否存在缺陷,设计了一种集ARM、FPGA和千兆以太网通信于一体的多通道高速数据采集系统。该系统并行采集16路脉冲信号,使用FPGA对脉冲信号定时计数,使用ARM作为采集板卡的主控芯片来控制各个模块之间协调运行,板卡与远端计算机之间通过千兆以太网实现数据传输和控制。信号采集实验表明:该系统能够并行采集工作频率50 MHz、计数定时范围为100μs~30 s的多路脉冲信号,实现基于千兆以太网的数据传输和板卡的运行控制,满足设计要求。     

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.     

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.     

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.