用微合金化和宏合金化改变Ni3Al合金的晶界结构

测量了二元多晶Ｎｉ３Ａｌ．含Ｂ．含Ｚｒ、Ｆｅ和含Ｈｆ、Ｆｅ的Ｎｉ３Ａｌ合金的ｅ＋寿命谱。在Ｎｉ３Ａｌ合金中加入Ｂ，Ｂ原子强烈地偏聚到Ｎｉ３Ａｌ合金的晶界上．使该处的价电子浓度与基体中的相近。含Ｚｒ、Ｆｅ和含Ｈｆ、Ｆｅ的Ｎｉ３Ａｌ合金的τ２都比二元Ｎｉ３Ａｌ的小．且以含Ｚｒ、Ｆｅ的τ２最小．表明在Ｎｉ３Ａｌ合金中加入Ｚｒ、Ｆｅ（或Ｈｆ，Ｆｅ）可增加合金中的金属键成分．使晶界处参与形成金属键的自由电子浓度增加，改善了晶界结构。     

用正电子湮没技术研究Ni－20Al－30Fe合金中的缺陷组态

测量了铸态、热轧和定向结晶三种不同工艺的Ｎｉ－２０Ａｌ－３０Ｆｅ的ｅ＋寿命谱：ｅ＋这三种试样的缺陷中的寿命十分相近．说明ｅ＋在该合金的空位、应错和晶界中的寿命相近．合金晶界缺陷处的自由电子密度和空位处的相当。在ＮｉＡｌ合金中加入Ｆｅ元素后．改善了合金的晶界结构．     

Cr和Mo对Fe3Al合金中微观缺陷和电子密度的影响

测量了二元Ｆｅ３Ａｌ及含Ｃｒ或Ｍｏ的Ｆｅ３Ａｌ合金的正电子寿命谱参数,计算了合金基体和缺陷处的价电子密度。实验结果表明,Ａｌ和Ｆｅ结合形成Ｆｅ３Ａｌ合金时,Ａｌ原子提供价电子与Ｆｅ原子的３ｄ电子形成局域的共价键。Ｆｅ３Ａｌ合金中金属键和共价键共存。Ｆｅ３Ａｌ合金晶界缺陷的开空间大于Ｆｅ空位或Ａｌ空位的开空间,晶界缺陷处价电子密度比基体低,晶界的键合力较弱。在Ｆｅ３Ａｌ合金中加入Ｍｏ,降低了合金中的     

乙酰二茂铁缩4—苯氨基硫脲与UO^2＋2,Hg^2＋,Ni^2＋,Zn^2＋,的…

乙酰二茂铁缩４－苯氨基硫脲（Ｃ１９Ｈ１９Ｎ３ＳＦｅ）与某些金属离子在无水乙醇中反应得到了希夫碱配合物Ｍ．Ｌ．Ｘ２．ｎＨ２Ｏ（Ｍ为ＵＯ＾２＋２，Ｈｇ＾２＋，Ｎｉ＾２＋，Ｚｎ＾２＋，Ｌ为Ｃ１９Ｈ１９Ｎ３ＳＦｅ；ＮＯ＾－３，Ｃｌ＾－，１／２ＳＯ＾２－４；ｎ＝０－６）并对配合物的组成及某些物理化学质进行了测试和表征。     

Pu（Ⅲ）光氧化工艺研究

对Ｐｕｒｅｘ工艺流程中１ＢＰ和２Ｂ混合流进行了紫外光照射，实现了Ｐｕ（Ⅲ）光氧化至Ｐｕ（Ⅵ）的“无盐”调价过程。光照７．５ｈ可使Ｐｕ（Ⅲ）全部氧化成了（Ⅵ）Ｐｕ（Ⅵ）含量＜１％，继续光照２．５ｈ仍能控制Ｐｕ（Ⅵ）含蛳＜７％。研究了Ｐｕ，ＨＮＯ３，Ｆｅ＾３＋浓度以及光源功率，温度变化对Ｐｕ（Ⅲ）光氧化的影响。结果表明，在Ｆｅ＾２＋ｔ Ｎ２Ｈ５＾＋浓度基本维持恒定的情况下，Ｐｕ从０．３０ｇ／ｌ，０＼６     

用正电子湮没技术研究深低温下Al—Li—Cu—Mg—Zr合金中的缺陷和电子密度

测量了欠时效和峰值时效的Ａｌ—Ｌｉ—Ｃｕ—Ｍｇ－Ｚｒ合金从深低温到室温升温过程的正电子湮没寿命谱．对ｅ＋寿命谱特征参数的分析表明．两种样品中的缺陷在升温过程中的运动规律是相似的。但峰值时效样品比欠时效样品回复缺陷的量更多；缺陷的平均开空间更大．而且随着δ＇（Ａｌ３Ｌｉ）相粒子的长大，样品基体中自由电子密度提高，增加了合金基体的强度．     

还原法制备LaNi4.15Al0.85合金及其吸氢性能研究

以Ｌａ,Ｎｉ和Ａｌ的氧化物为原料,在高温和氢的气氛下用ＣａＨ２还原制得ＬａＮｉ４．１５Ａｌ０．８５贮氢合金。Ｘ射线衍射证实此法制得的ＬａＮｉ４．１５Ａｌ０．８５的体相结构与熔炼法制备的相同。ＸＰＳ能谱数据显示在ＬａＮｉ４．１５Ａｌ０．８５原始表面上有一层活性镍。     

La—Ni—Al系贮氢材料的吸,放氢行为研究

研究了Ｌａ－Ｎｉ－Ａｌ系贮氢材料的吸、放氢行为。给出了ＬａＮｉ５－ｘＡｌｘ（ｘ＝０．２５、０．５０、０．７５、１．００）的吸附等温线、吸附速率及其氢化物的解吸平衡压与温度的关系曲线；定量确定了合金的吸附平衡压和饱和吸附容量等吸氢性能参数及基本的热力学参数ΔＨ㈠值和ΔＳ㈠值；初步探讨了上述参数与Ａｌ含量之间的定性关系。这为Ｌａ－Ｎｉ－Ａｌ系贮氢材料的应用提供了理论依据     

Ni3Al（0.98at%B）中硼原子扩散行为的正电子湮没研究

用正电子湮没技术研究了Ｎｉ３Ａｌ（０．９８ａｔ％Ｂ）合金经高温均匀化处理后，在空冷、炉冷、水冷条件下硼原子的扩散行为，结果表明，炉冷处理的合金中扩散至晶界的硼原子最多，并有微量硼化物在晶界处析出：水冷处理时扩散至晶界的硼原子最少，为使既有较多的硼原子扩散至晶界，又无硼化物在晶界析出，宜采用高温均匀化空冷的热处理工艺。     

JT—60中氚核燃耗研究

用一个基于闪烁光纤的新型１４ＭｅＶ中子探测器进行了时间分辨的氚核燃耗测量。测得的放电积分的氚核燃耗比是在０．３－２．０％范围内。基于经典慢化理论，分析了在关掉中性这后１４ＭｅＶ中子发射随时间的变化。假字快氚核的损失可表示为扩散率，根据对在关掉ＮＢ之后１４ＭｅＶ中子发射随时间的变化的模拟，确定的环向波纹增加而增加的扩散率值在０．０５－０．１５ｍ＾２；ｓ＾－１之间。     

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.