彩色电视机及计算机视屏前辐射水平的测定

本文介绍了对不同牌号、不同规格的７５台彩色电视机和３０台计算机视屏周围辐射水平的测量结果。采用ＦＪ－４０２型γ剂量仪分别测量在通电和断电情况下视屏前５ｃｍ处的Ｘ射线照射量率，采用ＦＪ－２２３型β测量仪量视屏中心和离视屏不同距离处的β计数率。     

电离室剂量计校准系统中监测仪的稳定性监测

以ＸＦ－Ⅱ型医用诊断Ｘ射线剂量仪为治疗水平电离室剂量计校准系统中的测仪器,对此监测仪器了两年多的监测、观察及性线回归分析处理,得监测值的线性相关系数ｒ〉０．９９９９９９９,标准偏差ｓ为（２．０－１０．０）＊１０＾－４Ｒ／ｍｉｎ（１Ｒ＝２．５８＊１０＾－４Ｃ／ｋｇ）;标准值与监测值比值平均为０．５２２４,比值的单次测量相对标准ｓｒ为０．６７％。这表明以ＸＦ－Ⅱ型医用诊断Ｘ射线剂量仪作为监测仪是稳定可     

用中子衍射研究稀土-富铁永磁合金磁结构和D(H)LAP晶体结构

用粉末中子衍射测量Ｈｏ２Ｆｅ９Ｇａ８－ｘＡｌｘ（ｘ＝２,４）和ＰｒＦｅ１０．５Ｍｏ１．５Ｎｘ的晶体结构和磁结构。衍射数据分别用ＲＸｉｅｔｖｅｌｄ结构精修程序ＲＩＥＴＡＮ和Ｆｕｌｌｐｒｏｆ处理。确定了替代原子Ｇａ,Ａｌ,Ｍｏ及间隙原子Ｎ的占位数以及磁性原子Ｈｏ,Ｆｅ,Ｐｒ的原子磁矩的大小和方向。     

BODY SURFACE EXPOSURE DISTRIBUTION OF EXAMINEES RECEIVED UPPER G．I．T．X－RAY EXAMINATION

ＢＯＤＹ　ＳＵＲＦＡＣＥ　ＥＸＰＯＳＵＲＥ　ＤＩＳＴＲＩＢＵＴＩＯＮ　ＯＦ　ＥＸＡＭＩＮＥＥＳ　ＲＥＣＥＩＶＥＤ　ＵＰＰＥＲ　Ｇ．Ｉ．Ｔ．Ｘ－ＲＡＹ　ＥＸＡＭＩＮＡＴＩＯＮＦｅｎｇＤｉｎｇｈｕａ（冯定华）ａｎｄＣｈｅｎｇＱｉｊｕｎ（程祺钧）（Ｆａｃｕ...     

工业X射线探伤机泄漏辐射调查与不合格产品的改进措施

本文介绍对北京地区使用和工业Ｘ射线探伤机泄漏辐射情况进行调查的方法与结果，共抽查了北京、上海等地８个厂家生产的２１台探伤机，其中北京、丹东和日本厂家生产的１６台，均为气体冷却的便携式探伤机，上海和德国生产的５台，为水冷或油冷却探伤机。用ＦＪ－３４７Ａ型Ｘ、γ剂量仪对探伤机Ｘ射线管头距靶１ｍ处的泄漏辐射空气比释动能率进行了测试。调查测试结果表明，依据我国机械工业部１９８５年发布的专业标准，５台水冷或     

乏燃料后处理溶液中U,Pu的^57Co原激发K—XRF分析

自制一套＾３７Ｃｏ源激发与Ｋ系Ｘ射线荧光（Ｋ－ＸＲＦ）分析系统，用＾３７Ｃｏ的ｋｅＶγ射线激发工艺溶液中Ｕ，Ｐｕ的Ｋ系Ｘ射线荧光，用ＨＰＧｅ探测器－多道微机分析系统进行测量，并以１２２ｋｅＶγ射线康昔顿散射线为内标，建立强度比－浓度校正曲线，快速同地测定了ＰＷＲ乏燃料后处理工艺溶液中Ｕ，Ｐｕ浓度，测定范围为０．５－２００ｇ／Ｌ，精密度为５．０％－１．５％。方法适于ＰＷＲ乏燃料后处理工艺中，Ｕ，Ｐｕ     

低剂量辐射对小鼠松果腺cAMP水平的影响

采用昆明系小鼠,全身照射低剂量Ｘ射线,剂量为５０￣５００ｍＧｙ,剂量率为１２．５ｍＧｙ／ｍｉｎ,照射后２４ｈ,检测松果腺ｃＡＭＰ含量变化,结果表明５０￣１００ｍＧｙＸ射线全身照射可使松果腺ｃＡＭＰ含量明显升高,其中７５ｍＧｙ组ｃＡＭＰ水平为最高（为假照射组的３．７倍ｐ〈０．００１）。而高剂量的对比观察１￣４Ｇｙ照射,松果腺ｃＡＭＰ水平呈降低趋势,其中２、４Ｇｙ照射组较假照射组明显减少（ｐ〈０．０５     

小剂量单次全射照射诱导小鼠免疫适应性反应的剂量与…

采用Ｘ射线单次全射照射，观察诱导小鼠免疫适应性反应的预照射剂量（Ｄ１剂量）范围，损伤性剂量（Ｄ２剂量）范围，及Ｄ１与Ｄ２最佳间隔时间。实验证实，当Ｄ２为１．５Ｇｙ时，０．０２５－０．１Ｇｙ（剂量率０．０９１２５Ｇｙ／ｍｉｎ）可诱导胸腺细胞自发增殖及脾细胞对ＬＰＳ的适应性反应。当Ｄ１为０．０７５Ｇｙ时，Ｄ２在１．０－１．５Ｇｙ（剂量率０．３３Ｇｙ／ｍｉｎ）范围内，胸腺细胞自发增殖及脾细胞对ＣｏｎＡ、     

高能Ar离子辐照单晶Si引起的损伤研究

用１１２ＭｅＶ Ａｒ离子以５０Ｋ的低温辐照了〈１１１〉取向的单晶Ｓｉ后在室温下采用Ｘ射线光电子谱（ＸＲＳ）、电子顺磁共振（ＥＰＲ）和红外光吸收（ＩＲ）技术对样品进行了分析。ＸＰＳ分析结果表明，表面处Ｓｉ以单元素和ＳｉＯ２两种形式共存，辐照对这两种形式Ｓｉ的２ｐ轨道电子的结合能影响较小。ＥＰＲ测量结果显示，Ｓｉ中的损伤产生明显地依赖于辐照剂量，当剂量为１．０×１０＾１４－１．８×１０＾１４ｃｍ＾－２     

小剂量照射后小鼠脾巨噬细胞对脾淋巴细胞功能的…

采用昆明小鼠，小剂量Ｘ射线全身照射５０ｍＧｙ￣２５０ｍＧｙ，剂量率为１２．５ｍＧｙ／ｍｉｎ。停照后不同时间处死动物，取出脾脏，用贴壁法分离脾巨噬细胞（ＭΦ）和淋巴细胞，检测受照后脾ＭΦ与受照的脾淋巴细胞功能变化的关系。结果表明，小剂量辐射可使脾ＭΦ功能增强，主要表现在７５ｍＧｙＸ射线全身照射后，脾ＭΦ对脾淋巴细胞ＣｏｎＡ（刀豆蛋白Ａ）反应增强，ＩＬ－１（白细胞介素１）分泌增多。受照的脾ＭΦ只对受照     

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.