应用于高精度稳流电源的直流零磁通误差传感器

研究了采用温度系数较低的坡莫合金材料制作的电流采样装置———直流零磁通误差传感器 ,简要分析了它的基本工作原理。该器件重 2 0 0 g ,功率损耗小于 1W ,无温度效应 ,结构简单 ,成本低廉。实测电源电流稳定度在 2 4h内≤ 1× 1 0 - 4。     

强流快脉冲测量用罗果夫斯基线圈

文章叙述了一个用于测量毫微秒脉冲大电流的罗果夫斯基线圈的特点、结构和主要参数。该装置已被用在80GW强流相对论性脉冲电子束加速器上监测二极管产生的束电流。实验表明,在直到260kA范围内,该装置性能良好。上升时间约5ns。     

零磁通检测器中探头磁芯材料性能研究

对不同种类的磁芯材料性能进行实验研究，结果表明高Br/Bs超微晶的磁芯较适合作零磁通检测器的探头材料，这种材料检测灵敏度高，对调制频率及调制幅度变化的影响小，常温下几乎不受温度变化的影响，且在市场上容易得到。另外，高μ铁氧体也可能适合作零磁通检测器的探头材料。     

一种非积分式瞬态电流传感器设计

瞬态电流（IDDT）测试技术自20世纪90年代提出以来受到了人们越来越多的关注。文章提出了一种非积分式CMOS电路IDDT传感器,该传感器能够有效的抑制噪声、准确的提取IDDT信号并较好的反应出故障信息,工作频率可达700MHz。     

动力线路信号分析监测反应堆冷却剂异常的改进方法

1引言 近年来，一种无干扰、无传感器的监测技术被用于核电站（NPP）电机驱动的旋转机械的监测。开发了电流信号分析方法（MCSA）作为电机工作监测的补充方法，并实现了商品化。MSCA用电机工作电流的频率信号取代了传感器。但是，由于必然会探测到在大的电能转换部件中存在的来自负载的非常微弱的信号，造成这种技术使用受限（Boashash和Black，1987）。     

数字化PWM技术在电流传感器中的运用

提出了利用DSP实现PID控制,结合DSP芯片内部定时器模块产生PWM信号,最后由该信号通过反馈电路产生相应的补偿电流,根据被测电流与补偿电流的安匝比关系即可得到待测电流值。经过实验测试,该设计可用于交直流信号测量。研究证明,该技术使新型电流传感器具有高稳定性。     

大发射电流密度Ir－Ce合金阴极的研究

制作了一种发射电流密度较大的铱－铈两相合金阴极。在１７７３Ｋ时，阴极零场发射电流密度为６７５Ａ／ｃｍ２，有效逸出功为２．７３ｅＶ；在１８２３Ｋ时，观察到最大发射电流密度超过２１．２Ａ／ｃｍ２。同时简介了阴极制作工艺和抗中毒情况以及未来的改进发展方向。     

电流型碳化硅探测器

本文从电流型半导体探测器的起源、传统电流型探测器在应用中的问题出发,论述了国内外在新型半导体探测器研制和电流型半导体探测器的研究现状。对半导体探测器结构和物理特性进行了研究,并重点介绍了电流型碳化硅（SiC）探测器的设计制作、响应性能研究、抗辐照性能研究等内容,为电流型半导体探测器的研究和应用提供参考。     

电流型碳化硅探测器

本文从电流型半导体探测器的起源、传统电流型探测器在应用中的问题出发,论述了国内外在新型半导体探测器研制和电流型半导体探测器的研究现状。对半导体探测器结构和物理特性进行了研究,并重点介绍了电流型碳化硅(SiC)探测器的设计制作、响应性能研究、抗辐照性能研究等内容,为电流型半导体探测器的研究和应用提供参考。     

大发射电流密度Ir—Ce合金阴极的研究

制作了一种发民流密度较大的铱－铈两相合金阴极。在１７７３Ｋ时，阴极零场发射电流密度为６．７５Ａ／ｃｍ＾２，有效逸出功为２．７３ｅＶ；在１８２３Ｋ时，观察到最大发射电流密度超过２１．２Ａ／ｃｍ＾２。同时简介了阴极制作工艺和抗中毒情况以及未来的改进发展方向。     

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.