包头地区环境陆地γ辐射剂量水平调查

本文报道了1984年包头地区环境陆地γ辐射剂量水平的调查结果。除白云鄂博矿区和包钢地区外的一般环境区,210个测量点按面积加权的陆地γ辐射剂量率和贯穿辐射剂量率平均值分别为6.35×10~(-8)Gy·h~(-1)(55.6mrad·y~(-1))和10.7×10~(-8)Gy·h~(-1)(93.7~(mrad)·y~(-1))。白云鄂博矿伴生放射性矿区(19个测点)和包钢剂量率较高的厂区(21个测点)的陆地γ辐射剂量率平均值分别为64.71×10~(-8)8Gy·h~(-1)(566.9mrad·y~(-1))和79.26×10~(-8)Gy·h~(-1)(694.4mrad·y~(-1)):分别为一般环境地区的10.2倍和12.5倍。     

内蒙古自治区环境天然贯穿辐射水平调查研究

本文报道了内蒙古自治区天然环境陆地γ辐射水平调查方案、质量保证措施及调查结果。在全区110万余km~2的面积上以25×25km网格布设了1018个测点。全区天然环境原野γ辐射剂量率(离地1m高处的空气吸收剂量率,下同)范围为(0.96—18.62)×10~(-8)Gy·h~(-1),按测点、面积和人口加杈均值分别为5.45、5.32和5.72×10~(-8)Gy·h~(-1);全区道路γ辐射剂量率范围为(1.07—26.08)×10~(-8),平均值为5.92×10~(-8)Gy·h~(-1);全区建筑物室内γ辐射剂量率范围为3.82—18.94)×10~(-8)Gy·h~(-1),按点、按人口加杈均值分别为9.26和9.49×10~(-8)Gy·h~(-1);宇宙射线电离成分所致空气吸收剂量率室外变化范围为(3.12—5.55)×10~(-8)Gy·h~(-1),按点、按人口加杈均值分别为3.93和3.85×10~(-1),室内变化范围为(2.60—4.66)×10~(-8)Gy·h~(-1),按点、按人口加杈均值分别为3.52和3.40×10~(-8)Gy·h~(-1);天然贯穿辐射剂量率室外变化范围为(8.31—11.26)×10~(-8)Gyh~(-1),按点、按人口加杈均值分别为9.38和9.57×10~(-8)Gyh~(-1),室内变化范围为(11.20—14.67)×10~(-8)Gyh~(-1),按点、按人口加杈均值分别为12.78和12.89×10~(-8)Gy·h~(-1);天然贯穿辐射所致人均年有效剂量当量及集体年有效剂量当量分别为0.84mSv和1     

河北省环境天然贯穿辐射水平调查研究

本文报道了1985—1987年河北省环境天然贯穿辐射剂量水平的调查方法及其结果。全省以25×25km网格均匀布点,共布设网格点285个,各类加密测点204个。结果表明:(1)原野天然γ辐射剂量率按测点、按面积和按人口加权的平均值分别为5.59、5.51和5.31×10~(-3)Gy·h~(-1);(2)道路的天然γ辐射剂量率按测点平均为5.11×10~(-8)Gy·h~(-1);(3)建筑物室内天然γ辐射剂量率按测点和按人口加权的平均值分别为9.39和9.17×10~(-8)Gy·h~(-1);(4)宇宙射线电离成分所致空气吸收剂量率按测点和按人口加权的平均值,室内分别为3.05和2.80×10~(-8)Gy·h~(-1),室外分别为3.38和3.11×10~(-8)Gy·h~(-1);(5)天然贯穿辐射剂量率(不包括中子成分)按测点和按人口加权的平均值,室内分别为12.44和11.97×10~(-8)Gy·h~(-1),室外分别为8.97和8.42×10~(-8)Gy·h~(-1),(6)天然γ辐射、宇宙射线和天然贯穿辐射所致的我省人均年有效剂量当量分别为0.50、0.25和0.75mSv,全省集体年有效剂量当量分别为2.7,1.3和4.0×10~4人·Sv。 首次发现“计马石”天然γ辐射异常本底区,该测点的原野、道路、建筑物室内的天然γ辐射剂量率分别为20.92、19.77和27.93×10~(-8)Gy·h~(-1)。     

山西省环境天然贯穿辐射水平调查研究

本文报道了山西省环境天然贯穿辐射剂量水平调查的方法和结果。全省以25×25km网格均匀布点,共布设网格点262个,各类加密点255个,调查结果表明:(1)山西省原野γ辐射剂量率按测点、人口和面积的加权均值分别为5.39、5.43和5.41×10~(-8)Gy·h~(-1);(2)道路γ辐射剂量率按测点平均值为4.84×10~(-8)Gy·h~(-1);(3)室内γ辐射剂量率按测点和人口加权均值分别为8.09和8.24×10~(-8)Gy·h~(-1);(4)宇宙射线电离成份所致空气吸收剂量率,按测点和人口加权均值,室内分别为3.46和3.36×10~(-8)Gy·h~(-1),室外分别为3.85和3.73×10~(-8)Gy·h~(-1);(5)天然贯穿穿辐射(不包括中子成分)剂量率,按测点和人口加权均值,室内分别为11.55和11.60×10~(-8)Gy·h~(-1),室外分别为9.24和9.16×10~(-8)Gy·h~(-1);(6)天然γ辐射、宇宙射线和天然贯穿辐射所致山西人均年有效剂量当量分别为0.46、0.30和0.76mSv,所致集体年有效剂量当量分别为1.2、0.77和2.0×10~4人·Sv。     

福建省环境天然贯穿辐射水平调查

本文报道了福建省环境天然贯穿辐射剂量水平调查的方法和结果。全省以25×25 km 网格均匀布点,共布设网格点173个,各类加密点170个。调查结果表明:(1)原野天然γ辐射剂量率按测点、面积和人口的加权均值分别为9.26、9.23和8.71×10~(-8)Gy·h~(-1);(2)道路天然γ辐射剂量率按点平均为10.64×10~(-8)Gy·h~(-1);(3)建筑物室内天然γ辐射剂量率按测点和人口的加权平均值分别为15.58和15.65×10~(-8)Gy·h~(-1);(4)宇宙射线电离成分所致空气吸收剂量率按测点和人口的加权平均值,室内分别为2.42和2.39×10~(-8)Gy·h~(-1),室外分别为3.03和2.99×10~(-8)Gy·h~(-1);(5)天然贯穿辐射剂量率(不包括中子成分)按测点和人口的加权平均值,室内分别为18.00和18.05×10~(-8)Gy·h~(-1),室外分别为12.29和11.70×10~(-8)Gy·h~(-1);(6)天然γ辐射、宇宙射线和天然贯穿辐射所致福建人均年有效剂量当量分别为0.84、0.22和1.06 mSv,全省集体年有效剂量当量分别为2.31、0.60和2.91×10~(-4)人·Sv。调查中发现“鬼头山”天然γ辐射异常本底区。该区(约2km~2)的原野天然γ辐射剂量率平均值约为40.94×10~(-8)Gy·h~(-1),是全省平均值的4.4倍。     

新疆维吾尔自治区环境天然贯穿辐射水平调查研究

本文报道了新疆维吾尔自治区环境天然贯穿辐射剂量水平调查的方法和结果。全区布设25×25km 和50×50km 网格点740个,各类加密点884个。调查结果表明:(1)原野天然γ辐射剂量率按测点、面积和人口的加权均值分别为5.81、5.94和5.76×10~(-8)Gy.h~(-1);(2)道路天然γ辐射剂量率按点平均为5.63×10~(-8)Gy·h~(-1);(3)建筑物室内天然γ辐射剂量率按测点和人口的加权平均值分别为9.92和9.86×10~(-8)Gy·h~(-1);(1)宇宙射线电离成分所致空气吸收剂量率按测点和人口的加权平均值,室内分别为3.90和3.55×10~(-8)Gy·h~(-1)室外分别为4.40和4.01×10~(-8)Gy·h~(-1);(5)天然贯穿辐射剂量率(不包括中子成分)按测点和人口的加权平均值.室内分别为13.82和13.42×10~(-8)Gy·h~(-1),室外分别为10.22和9.77×10~(-8)Gy·h~(-1);(6)天然γ辐射、宇宙射线和天然贯穿辐射所致新疆人均年有效剂量当量分别为0.53、0.32和0.86mSv,天然贯穿辐射所致全区年集体有效剂量当量为1.13×10~4人·Sv。     

河南省环境天然贯穿辐射水平调查研究

本文报道了河南省环境天然贯穿辐射剂量水平的调查方法及其结果。全省以25×25 km 网格均匀布点,共布设网格点259个,各类加密测点351个。结果表明:(1)原野γ辐射剂量率按测点、按面积和按人口加权的平均值分别为6.14、6.13和5.84×10~(-8)Gy·h~(-1);(2)道路γ辐射剂量率按测点平均为5.60×10~(-8)Gy·h~(-1);(3)建筑物室内天然γ辐射剂量率按测点和按人口加权的平均值分别为9.68和9.53×10~(-8)Gy·h~(-1);(4)宇宙射线电离成分所致空气吸收剂量率按测点和人口加权的平均值,室外分别为3.02和2.98×10~(-8)Gy.h~(-1),室内分别为2.72和2.68×10~(-8)Gy·h~(-1)(5)天然贯穿辐射剂量率(不包括中子成分)按测点和按人口加权的平均值,室外分别为9.16和8.82×10~(-8)Gy·h~(-1),室内分别为12.39和12.21×10~(-8)Gy·h~(-1);(6)天然γ辐射、宇宙射线和天然贯穿辐射所致的我省人均年有效剂量当量分别为0.52、0.24和0.76mSv,所致集体年有效剂量当量分别为3.88、1.80和5.68×10~4人·Sv。     

安徽省环境天然贯穿辐射水平调查研究

本文报道1987年2—12月安徽省环境天然贯穿辐射剂量水平调查的方法及结果。全省共布设测点777个,其中按25×25km 网格在全省均匀布设的网格点216个,各类加密测点561个。调查测量结果表明:(1)原野天然γ辐射剂量率按测点、按面积和人口的加权平均值分别为5.67、5.62和5.55×10(?)Gy·h~(-1);(2)道路的天然γ辐射剂量率按测点平均为5.38×10~(-8)Gy.h~(-1);(3)建筑物室内天然γ辐射剂量率按测点和按人口的加权平均值分别为9.59和9.36×10~(-8)Gy·h~(-1);(4)宇宙射线电离成分所致空气吸收剂量率按测点和按人口的加权平均值,室内分别为2.64和2.62×10~(-8)Gy·h~(-1),室外分别为2.95和2.94×10~(-8)Gy·h~(-1);(5)环境天然贯穿辐射剂量率(不包括中子成分)按测点和按人口加权的平均值,室内分别为12.23和11.99×10~(-8)Gy·h~(-1),室外分别为8.62和8.49×10~(-8)Gy·h~(-1);(6)天然γ辐射、宇宙射线和环境天然贯穿辐射所致的我省人均年有效剂量当量分别为0.51、0.24、0.75mSv,全省集体年有效剂量当量分别为2.5、1.2和3.7×10~4人·Sv。调查发现原徽州地区炭化砖建筑物室内γ辐射剂量率均值为25.56×10~(-8)Gy·h~(-1),明显高于全省建筑物室内的调查结果,应引起重视。     

广东省环境天然贯穿辐射水平调查研究

本文报道了广东省环境天然贯穿辐射水平的调查方法和结果。全省基本以25×25km 网格均匀布点336个。调查结果表明:(1)广东省原野γ辐射剂量率(离地面1m 高处的空气吸收剂量率,下同)按网格,点(以下简称为测点)、人口和面积的加权均值分别为8.53、8.48和8.55×10~(-8)Gy·h~(-1);(2)道路γ辐射剂量率按测点平均为9.10×10~(-8)Gy·h~(-1);(3)室内γ辐射剂量率按测点和人口加权均值分别为13.39和13.68×10~(-8)Gy·h(-1);(4)宇宙射线致电离成分(不包括中子)所致空气吸收剂量率按测点和人口加仅均值,室内分别为2.39和2.36×10~(-8)Gy·h~(-1),室外分别为2.74和2.73×10~(-8)Gy·h~(-1);(5)天然贯穿辐射剂量率,按测点和人口加权均值,室内分别为15.78和16.04×10~(-8)Gy·h~(-1);室外分别为11.27和11.28×10~(-8)Gy·h~(-1);(6)宇宙射线、天然γ辐射和天然贯穿辐射所致居民人均年有效剂量当量分别为0.21、0.77和0.98mSv;所致集体年有效剂量当量分别为1.2、4.6和5.8×10~4人·Sv。     

湖南省环境天然贯穿辐射水平调查研究

本文报道了湖南省环境天然贯穿辐射水平调查的方法和结果。全省以25×25km 网格均匀布点,共布设网格点309个,各类加密点1007个。调查结果表明:(1)湖南省原野γ辐射剂量率按测点、人口和面积的加权均值分别为7.11、6.90和7.07×10~(-8)Gy·h~(-1);(2)道路γ辐射剂量率按测点平均值为7.05×10~(-8)Gy·h~(-1);(3)室内γ辐射剂量率按测点和人口加权均值分别为10.43和10.56×10~(-8)Gy·h~(-1);(4)宇宙射线电离成分所致空气吸收剂量率按测点和人口加权均值,室内分别为2.67和2.66×10~(-8)Gy·h~(-1);室外分别为3.00和2.98×10~(-8)Gy·h~(-1);(5)天然贯穿辐射(不包括中子成分)剂量率按测点和人口加权均值,室内分别为13.1和13.2×10~(-8)Gy·h~(-1),室外分别为10.1和9.88×10~(-8)Gy·h~(-1);(6)天然γ辐射、宇宙射线和天然贯穿辐射所致湖南省人均年有效剂量当量分别为0.58、0.24和0.82mSv,所致集体年有效剂量当量分别为3.1、1.3和4.4×10~4人·Sv。     

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.