山西广播电视卫星地球站电磁辐射环境影响评价

报道了山西广播电视卫星地球站环境影响的评价工作。电磁辐射环境现状调查结果表明,评价区环境电磁辐射最高值为４．７２５＊１０＾－５μＷ／ｃｍ＾２,属正常环境水平;发射天线对地面环境电磁辐射贡献最大为３．０２＊１０＾－６μＷ／ｃｍ＾２;高功放室对工作岗位电磁辐射贡献最大为３．１６μＷ／ｃｍ＾２;同时,计算了天线前方建筑物的允许建筑高度。     

In^＋离子注入蓝宝石（α—Al2O3单晶）的表面改性研究

研究了〈０００１〉和〈１＾－２１０〉晶向蓝宝石（α－Ａｌ２Ｏ３单昌）在注入３６０ｋｅＶ、１×１０＾１６ｃｍ＾－２或１００ｋｅＶ、６×１０＾１６ｃｍ＾－１的Ｉｎ＾＋后产生的损伤、注入层的性能变化和退火行为。实验结果表明，退火过程中损伤的恢复和Ｉｎ的分布与退火气氛有关：在１００ｋｅＶ、６×１０＾１６ｃｍ＾－２的Ｉｎ＾＋注入时，注入层电阻率降低了１０个量级，大小为６．８×１０＾３Ω·ｃｍ，表面损伤层的显     

超导托克马克TRIAM—1M的最新进展

在超导托卡马克ＴＲＩＡＭ－１Ｍ上,广泛开展了稳态托卡马克反应堆的研究。用２．４５ＧＨｚ低杂波电流驱动已演示了密度为ｎｃ＝２＊１０＾１８ｍ＾－３,持续时间超过２ｈ的放电。在孔栏５ＭＷ．ｍ＾－２的高平均壁负载条件下,用８．２ＧＨｚ的杂波电流驱动使ｎｃ＝２＊１０＾１９ｍ＾－３高密度等离子体维持了１ｍｉｎ。     

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。     

高能（MeV级）氧离子注入本征型GaAs的电性能及注入损伤退火行为的研究

在本征型ＧａＡｓ中注入２．０ＭｅＶ（剂量１．０×１０＾１５／ｃｍ＾２）＋２．９ＭｅＶ（剂量１．１×１０＾１５／ｃｍ＾２）的＾１６Ｏ，使氧在约１．５－２．５μｍ之间形成均匀分布。注入样品分别经４００－８００℃、１５ｍｉｎ热退火后的电阻率测量表明，经５００℃和６００℃退火后的样品具有高的电阻率（～１０＾８Ω·ｃｍ）；而当退火温度进一步升高时，其电阻率逐渐下降，并具有ｐ型导电行为。沟道ＲＢＳ分析表明，当     

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     

单晶SiO2表面Ag注入层的结构与光吸收的研究

报道了在室温和２００ｋＶ电压下，以６．７×１０＾１６Ａｇ＾＋／ｃｍ＾２剂量注入单晶ＳｉＯ２的研究结果。Ｒａｍａｎ谱表明６．７×１０＾１６Ａｇ＾＋／ｃｍ＾２注入使单晶ＳｉＯ２非晶化；ＸＰＳ结果初步说明注入的Ａｇ以金属态存在；ＲＢＳ谱表明Ａｇ在ＳｉＯ２中呈现双峰分布。ＴＥＭ明场像显示了Ａｇ在注入层中形成两种主要尺寸的球形超微粒。较大的直径为２５ｎｍ左右，分布相当密集；较小的直径大约为５ｎｍ。注入层的光     

高剂量铂和钇离子注入Al2O3单晶的表面改性

研究了〈０００１〉和〈１２↑－１０〉晶向α－Ａｌ２Ｏ３单晶在高剂量的Ｙ、Ｐｔ离子注入后产生的损伤,注入层的性能变化和退火行为。实验结果表明,在室温,１７１ｋｅＶ、１×１０＾１７／ｃｍ＾２Ｙ离子注入的〈１２↑－１０〉α－Ａｌ２Ｏ３单晶的表面层约有１３９ｎｍ厚被无定形化。而１５８ｋｅＶ、９×１０＾１７／ｃｍ＾２Ｐｔ离子注入的〈０００１〉α－Ａｌ２Ｏ３单晶的表面层不产生无定形,且实际离子注入进衬底的剂量     

几种特殊靶的制备方法

文章了几种特殊靶的制备，包括７０ｍｇ．ｃｍ＾－２的自支撑Ｂｉ靶、Ｍｏ封窗膜、１５－５０μｇ．ｃｍ＾－２的自撑Ｓｃ靶（ＣＤ２）ｎ靶和７０μｇ．ｃｍ＾－２的自支撑Ｃｏ靶。     

In~+离子注入蓝宝石(α-A1_2O_3单晶)的表面改性研究

研究了＜０００１＜和＜１２１０＞晶向蓝宝石（α－Ａｌ２Ｏ３单晶）在注入３６０ｋｅＶ．１×１０￣１６ｃｍ￣－２或１００ｋｅＶ、６×１０￣１６ｃｍ￣－２的Ｉｎ￣＋后产生的损伤、注入层的性能变化和退火行为。实验结果表明，退火过程中损伤的恢复和Ｉｎ的分布与退火气氛有关：在１００ｋｅＶ、６×１０￣１６ｃｍ￣－２的Ｉｎ￣＋注入时，注入层电阻率降低了１０个量级，大小为６．８×１０￣３·ｃｍ，表面损伤层的显微硬度提高了９２％；在３６０ｋｅＶ，１×１０￣１６ｃｍ￣－２的Ｉｎ＋注入时，其表面损伤层的显微硬度提高了４５％，在空气中不同温度下退火后，其显微硬度的变化和损伤的变化具有相同的规律。     

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.     

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.     

微型X射线管空气比释动能和能谱的测量

为研究微型X射线管的特性,通过电离室测量光管出射口30 cm远处的空气比释动能,使用高纯锗探测器分别测量了Ag过滤和Cu过滤下的X射线能谱。结果表明,空气比释动能随电流的增加有线性增加的趋势,能谱图明显的观察到银的两个特征X射线。完成了微型X射线管空气比释动能和能谱的测量方法以及实验测量的工作,为微型x射线管下辐射质的建立提够了条件基础。     

Gamma-ray attenuation technique for measuring void fraction in horizontal gas-liquid two-phase flow

The measurement of void fraction is of importance to the oil industry and chemical industry. In this article, the principle and mathematical method of determining the void fraction of horizontal gas-liquid flow by using a single-energy γ-ray system is described. The γ-ray source is the radioactive isotope of 241Am with γ-ray energy of 59.5 keV. The time-averaged value of the void fraction in a 50.0-mm i.d. transparent horizontal pipeline is measured under various combinations of the liquid flow and gas flow. It is found that increasing the gas flow rate at a fixed liquid flow rate would increase the void fraction. Test data are compared with the predictions of the correlations and a good agreement is found. The result shows that the designed γ-ray system can be used for measuring the void fraction in a horizontal gas-liquid two-phase flow with high accuracy.