5.0MeV和9.5MeV快中子辐照在GaAs中产生的辐射损伤的正电子湮没研究

采用正电子湮没寿命测量方法研究了５．０ＭｅＶ和９．５ＭｅＶ快中子辐照在ＧａＡｓ中产生的辐射损伤，实验结果表明１０＾１１－１０＾１２ｎ／ｃｍ＾２注量的中子辐照只产生单空位缺陷１０＾１３ｎ／ｃｍ＾３注量的中子辐照产生单空位和双空位缺陷，１０＾１２ｎ／ｃｍ＾２注量的９．５ＭｅＶ中子辐照的ＧａＡｓ经４５０－６２０℃退火产生三空位缺陷，产生的缺陷浓度随中子能量和注量的增大而增大，但缺陷产生率对中子注量更灵敏     

GaP高能重离子辐照损伤及退火的正电子湮没研究

用正电子湮没寿命技术研究２．４＊１０＾１５／ｃｍ＾２和２．２＊１０＾１６／ｃｍ＾２ ８５ＭｅＶ＾１９Ｆ离子辐照ＧａＰ的辐照损伤及其退火效应。结果表明,高低两种注量辐照在ＧａＰ中产生浓度较高的单空位。在３００－１０２３Ｋ温度范围内测量了正电子湮没寿命温度的变化。低注量辐照品在退火过程中有双空位的形成;而高注量辐照样品中观察到比双空位更复杂的缺陷形式,其完全被退火的温度比低剂量辐照的高２５０Ｋ。     

高注量快中子辐照在α—Al2O3中产生空洞的正电子湮没研究

采用正电子湮没技术研究３×１０＾２０／ｃｍ＾２中子注量，Ｅｎ≥１ＭｅＶ快中子辐照在α－Ａｌ２Ｏ３中产生的辐照效应，实验发现α－Ａｌ２Ｏ３在辐照后的８５０℃退火形成尺寸约为０．７ｎｍ的空洞。     

热中子辐照提高掺硼YBaCuO超导体Jc的研究

掺杂天然硼的熔融织构生长（Ｍｅｌｔ－ｔｅｘｔｕｒｅｄＧｒｏｗｔｈ）的ＹＢｘＢａ２Ｃｕ３Ｏｙ（ｘ＝０．０１５,０．０３５）超导体经注量为５＊１０＾１７ｃｍ＾－２的热中子辐照后,磁临界电流密度Ｊｃ增至３．８倍。＾１０Ｂ（ｎ,α）＾Ｌｉ、＾７Ｌｉ＊（Ｑ＝＋２．７９ＭｅＶ）核反应出射的高能粒子能在超导体中产生均分布的,可以作为磁通钉扎中心的辐照伤,以便提高Ｊｃ。掺硼超导体热中子辐照后射性副产物的半衰期较短     

探测太阳中微子的InP探测器地下探测阵列的蒙特卡洛模拟

为了解决太阳中微子丢失之迷，根据＾１１５Ｉｎ的特性，提出化合物半导体探测器ＩｎＰ地下探测阵列方案，通过Ｍｏｎｔｅ－Ｃａｒｌｏ模拟计算，得到探测效率，本底的错误判选率和信噪比。     

75MeV／u^16O离子在辐照生物实验区产生的中子角分布

应用Ａｌ为阈探测器对７５ＭｅＶ／ｕ＾１６Ｏ离子在辐照生物研究区产生的Ｅｎ〉６ＭｅＶ中子的角分布进行了实验测量，以了解辐照生物实验区的中子分布情况，为进一步开展的重离子冶癌研究提供辐射防护的实验数据。实验结果表明实验区产生的中子具有明显的前冲分布。     

裂变快中子辐照在GaAs中产生缺陷的正电子湮没研究

采用自电子湮没寿命测量方法研究了注量为６．５×１０＾１５／ｃｍ＾２和１．４×１０＾１４／ｃｍ＾２，Ｅｎ≥１ＭｅＶ的裂变中子辐照在掺Ｓｉ，Ｎ型单晶ＧａＡｓ产物的缺陷，此辐照在ＧａＡｓ中产生单空位和双空位缺限，缺陷浓度于比于辐照注量，高温退火产生三空位缺陷及小空位团，单空位，双空位和三空位缺陷的退火温度分别为２５０，４５０，６５０℃。     

经软X射线辐照的InP的表面损伤态

采用Ｘ光激发光电子能谱对经同步辐射软Ｘ光辐照的ＩｎＰ表面进行了分析。实验结果表明：ＩｎＰ表面辐照损伤与辐照Ｘ光的能量及剂量有关,尤其是具有近Ｐ原子Ｋ壳层共振吸收能量的软Ｘ光辐照与其它Ｘ射线辐照相比,其结果有所不同。文中就实验结果的机制进行了初步探讨。     

47MeV／u的C^6^＋在CaVSn：YIG中辐照效应的研究

用兰州重离子研究装置（ＨＩＲＦＬ）首次进行了４７ＭｅＶ／ｕ的Ｃ＾６＾＋离子辐照ＣａＶＳｎ：ＹＩＧ的实验。通过穆斯堡尔效应和正电子寿命测量对４７ＭｅＶ／ｕ的Ｃ＾６＾＋离子在ＣａＶＳｎ：ＹＩＧ中的辐照效应进行了初步研究。发现辐照导致内磁场方向趋于各向同性分布，由穆斯堡尔谱未观察到非晶化现象。缺陷的数量随Ｃ＾６＾＋离子在样品中电子能量损失的增加而增加。     

25MeV／u ^40Ar^14＋辐照肝癌细胞的生物学效应

讨论了２５ＭｅＶ／ｕ ＾４０Ａｒ＾１４＋对培养的肝癌细胞ＳＭＭＣ－７７２１的生物学效应。结果表明：辐照后的癌细胞中出现多种染色体畸变类型，微核率比对照高得多，肝癌细胞的辐射受损程度与剂量呈正相关性，分次照射时，修复机制被逐渐激活，等剂量辐照的细胞损伤程度随辐照次数的增加而减轻。     

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.     

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.     

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.