Si—SiO2及其在电离辐照下的等离激元

用ＸＰＳ分析技术对抗辐射加固与非加固的Ｓｉ－ＳｉＯ２进行了电离辐照前后Ｓｉ的一级等离激元（定位于Ｂ．Ｅ．１１６．９５ｅＶ）及ＳｉＯ２一级等离激元（定位于Ｂ．Ｅ．１２２．０ｅＶ）的研究。实验结果表明：存在一个由这两种等离激元组成的界面，在电离辐射的作用下，此界面区向ＳｉＯ２表面方向展宽，界面中心向ＳｉＯ２表面方向移动；两种Ｓｉ－ＳｉＯ２界面区中的ＳｉＯ２一级等离激元的浓度在正电场中辐照均随辐照剂量的增加而增加，而非加固样品中一级等离激元浓度在正电场中随辐照剂量的变化所产生的变动快于加固样品；在同一辐照剂量下加正电样品中等离激元浓度的变化远明显于不加电样品。     

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     

P沟MOSFET／FIPOS的γ射线总剂量辐照特性

采用高选择和自终止多孔氧化硅全隔离技术的制备了高质量的ＳＯＩ材料，研究了在该材料上采用２μｍＣＭＯＳ工艺制备的不同沟道长度的Ｐ沟ＭＯＳＦＥＴ的＾６０Ｃｏγ射线总剂量辐照特性，表明经５ｋＧｙ（Ｓｉ）辐照后，器件仍有特性，但阈值电压有较大的漂移，这主要是由栅氧化层中的辐照感生电荷而引起，不同的沟长度ＰＭＯＳＦＥＴ的辐照特性有基本相同，经一段时间室温退火，阈值电压出现回漂。     

MOSFET模拟特性的电离辐射响应

通过研究６０Ｃｏγ射线对ＭＯＳＦＥＴ的线性特性和输出特性的影响，定性地描述了氧化物电荷积累和Ｓｉ／ＳｉＯ２界面态增加分别与Ｐ－ＭＯＳＦＥＴ和Ｎ－ＭＯＳＦＥＴ的迁移率μ退化、跨导ｇｍ下降以及输出特性曲线漂移等的依赖关系。试验结果表明，对于Ｐ－ＭＯＳＦＥＴ，电离辐照感生氧化物电荷积累和界面态密度增加都将导致器件模拟特性的退化；对于Ｎ－ＭＯＳＦＥＴ，这种退化主要由辐射感生Ｓｉ／ＳｉＯ２界面态密度增加所支配。     

气氛对γ射线辐照聚碳硅烷陶瓷先驱丝的化学结构和 …

将聚碳硅烷先驱丝分别在Ｎ２，Ｈｅ，ＮＨ３和限量空气条件下封装于石英管中，用γ射线辐照至特定剂量后，在高温条件下热解转化为ＳｉＣ陶瓷材料，结果表明：除在大气条件下因Ｓｉ－Ｈ的氧化，在波数为３４００ｃｍ＾－１处产生吸收峰以外，其它氛中辐照产物的红外吸收光谱并无明显差异。用热重－红外光谱（ＴＧＡ－ＦＴＩＲ）联用技术和气相色谱法检测到热解过程中有ＣＨ４和大量的Ｈ２析出。当吸收剂量达到１３．８ＭＧｙ时，辐照     

γ辐照对低密度聚乙烯的动态力学性能和热行为的影响

经γ辐照后所有样品的储能模量（Ｅ＇）都有所增加，从阻尼因子（ｔａｎ δ）的温度谱上所观察到β和α转变温度随辐照剂量的增加向高温方向移动。热分析结果表明，辐照后样品的热学参数Ｔｍ、△Ｈｍ和Ｔｄ随剂量的增加而降低。     

电子束辐照聚碳硅烷热解合成SiC陶瓷材料

利用加速器产生的电子束（ＥＢ）在空气中辐射聚碳硅烷（ＰＣＳ），以使之定期关结构，然后经高温热解转化成ＳｉＣ陶瓷。结果表明：在辐照产物中形成了Ｓｉ－Ｃ－Ｓｉ以及Ｓｉ－Ｏ－Ｓｉ等交联结构，热解温度以及热解陶瓷产率都随辐射吸收剂量增加而明显提高。通过ＴＧ－ＩＲ联用分析技术，在热解产物中检测到了低分子量ＰＣＳ以及ＣＨ４等小分子化合物，在吸收剂量高于２．３ＭＧｙ时，ＰＣＳ主要通过析出ＣＨ４而热解成ＳｉＣ。     

DL—苏氨酸辐照效应的谱学研究

用电子自旋（ＥＳＲ）波谱、固体高分辨核磁共振＾１３Ｃ ＮＭＲ谱以及Ｘ－衍射光谱，探讨了ＤＬ－苏氨酸（Ｔｈｒ）的γ辐照稳定性。Ｔｈｒ的＾１３Ｃ ＮＭＲ化学位移和Ｘ－射线衍射数据结果表明，Ｔｈｒ多晶固体在１００ｋＧｙ剂量范围内的化学结构是稳定的。ＥＳＲ谱强度和＾１３Ｃ共振谱线宽随着剂量的增加而增大，是辐照自由基浓度的变化所致。     

注氟MOSFET的质子辐照效应

对干Ｏ２和Ｈ２＋Ｏ２栅氧化注Ｆ的Ｓｉ栅Ｐ沟和Ｎ沟ＭＯＳＦＥＴ进行了８ＭｅＶ和１２ＭｅＶ质子辐照试验，通过分析阈电压和Ｌｄｓ－Ｖｇｓ亚阈特性的辐射响应，发现ＭＯＳ结构栅介质中Ｆ的引入能明显抑制辐射感生氧化物电荷的积累和Ｓｉ／ＳｉＯ２界面态的产生，导致ＰＭＯＳＦＥＴ较小的阈电压负向漂移和ＮＭＯＳＦＥＴ阈电正向回漂，且不受质子辐照能量的影响。     

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     

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.