γ辐照后30％TRPO—煤油对Tc的萃取与保留

研究了γ辐照对30％TRPO-煤油对Tc萃取性能的影响以及从辐照后的负载有机相中分别用5.5mol/LHNO     

三烷基(混合)氧膦的结构分析及其对镎、钚的萃取

本文用红外光谱和核磁共振谱研究了TRPO的组成及萃取结构,证明了萃取是由膦酰基上氧原子的孤对电子配位引起的,萃取络合物为配位络合物。研究了 TRPO萃取水和硝酸的平衡常数及络合物结构形式。还用~(238)Np示踪和α液体闪烁测量研究了TRPO-煤油-硝酸体系中各种价态的镎、钚萃取和反萃取情况。     

P_(204)去除氧化镧中放射性的工艺研究

本文研究了在HNO_3体系中,P_(204)萃取La和Ac的机理及影响La,Ac萃取分离因素,给出了La,Ac分配的数学摸型。在此基础上,进行了试管串级和离心萃取器多级逆流萃取实验。实验结果表明:La的收率大于95%,放射性去污大于500倍,Ca去污大于1000倍,产品符合荧光材料的要求。给出P_(204)去除La_2O_3中放射性的工艺流程,可用于工业生产。     

三烷基(混合)氧膦(TRPO)对Fe(Ⅲ)萃取性能的研究

研究了TRPO萃取剂对Fe(Ⅲ)的萃取性能,测定了在该实验条件下Fe(Ⅲ)的萃取随萃取平衡时间、水相中HNO_3的浓度、Fe~(3-)离子浓度、温度的变化。计算了TRPO萃取Fe(Ⅲ)的反应焓变ΔH,熵变ΔS及表观平衡常数K。结果表明,30％TRPO-煤油萃取体系萃取高放废液的模拟料液时,三相的产生是与水溶液中Fe~(3 )离子的浓度紧密相关的。当水溶液中[H~ ]=1.5 mol/L,[Fe~(3 )]_初始>8.0g/L时,30％TRPO-煤油的萃取体系即出现三相。同时测定了分相后,轻、重两个有机相的体积比和Fe含量比随水相Fe~(3 )离子初始浓度的变化。     

三烷基(混合)氧膦(TRPO)对Fe(Ⅲ)萃取性能的研究

研究了TRPO萃取剂对Fe(Ⅲ)的萃取性能,测定了在该实验条件下Fe(Ⅲ)的萃取随萃取平衡时间、水相中HNO_3的浓度、Fe~(3 )离子浓度、温度的变化。计算了TRPO萃取Fe(Ⅲ)的反应焓变ΔH°,熵变ΔS°及表观平衡常数K。结果表明,30％TRPO-煤油萃取体系萃取高放废液的模拟料液时,三相的产生是与水溶液中Fe~(3 )离子的浓度紧密相关的。当水溶液中[H~ ]=1.5mol/L,[Fe~(3 )]_(初始)>8.0g/L时,30％TRPO-煤油的萃取体系即出现三相。同时测定了分相后,轻、重两个有机相的体积比和Fe含量比随水相Fe~(3 )离子初始浓度的变化。     

用三烷基(C_6-C_8)氧磷(TRPO)从强放废液中萃取锕系、镧系元素的研究

本文研究了三烷基(C_6-C_8)氧膦(TRPO)对锕系、镧系元素及裂变产物的萃取行为;测得了铀、镎、钚、镅、锔等20余种离子在30％TRPO-煤油-硝酸溶液中的分配比以及部分离子的被萃络合物形式;测定了稀释剂、萃取剂浓度、温度、盐析剂等因素对TRPO萃取三价锕系和镧系元素的影响,为用TRPO萃取剂从强放废液中提取有用元素提供了基础数据。     

三烷基(混合)氧膦(TRPO)提取锕系元素工艺流程的研究

本文用试管串级及离心萃取器串联,研究了用30％TRPO-煤油从模拟动力堆核燃料后处理强放废液中清除α核素的工艺流程及分离条件。结果表明:TRPO是清除α核素的优良萃取剂;所推荐的流程可同时提取U、Np、Pu、Am、Cm、Tc、R.E等多种核素,对超铀α核素的清除率大于99.9％,工艺过程较为简单,是很有前途的流程。     

用三烷基氧膦(TRPO)从强放废液中去除锕系元素——TRPO对镅和某些镧元素的萃取

本文测定了三烷基氧膦(TRPO)萃取镅和镧系元素(Ce、Eu、Nd)的分配比,在实验的基础上建立了计算分配比的半经验数学模型,并利用这一模型对用30％TRPO-煤油溶液从强放废液中去除镅的多级逆流萃取中各级浓度的变化进行了计算。用模拟料液在微型环隙式离心萃取器逆流萃取实验中对计算结果进行了验证。结果表明,30％TRPO可以有效地从中等浓度硝酸介质中去除镅。据此提出了用TRPO萃取从强放废液中去除99.9‰镅的流程推荐数据。     

γ辐照30%三烷基氧化膦—煤油体系萃取乳化的研究

研究了γ辐射三烷基氧化膦（TRPO）的乳化性能。实验表明，萃取水相酸度的增加，有利于去乳化作用。γ辐射对30?RPO-煤油-硝酸体系的乳化作用有显著影响，不同厂家生产的TRPO具有不同的乳化性能。γ辐照的磷酸三丁酯（TBP）-煤油-硝酸体系较RTPO-煤油-HNO3体系分相和去乳化速度较快。但当用5?a2CO3溶液洗涤上述两个体系时，TBP-煤油体系有机相去乳化速度较慢，其平衡水相有乳化现象，面TRPO-煤油体系虽分相慢，但分相后有机相的去乳化速度较快，其平衡水相无乳化现象。     

SUP>228/SUP>Ra-SUP>228

研究了以钍为原料制备228Ra-228Ac发生器的方法。在2 mol/L HNO3的Th(NO3)4溶液中,先用50%TBP/CCl4萃取剂,通过两次错流萃取,除去约75%的钍,再用30%TRPO/煤油两次萃取,钍的去污因子大于105,在这个过程中,Ra的回收率大于99%。用自制的-αMnO2研究了酸性条件下MnO2对水溶液中Ra和钍系核素的静态吸附及对Ra,Ac的动态吸附。研究结果表明,在室温下,二氧化锰对Ra,Ac的吸附分配系数Kd随酸度的升高而下降,除Pb外,对钍及钍系其它核素不吸附。选择在0.2 mol/L HNO3介质中吸附时,Ra-Ac的分离效果最好,分离因子接近104。用0.2 mol/L HNO3解吸吸附柱上Ra衰变的Ac可得到很纯的228Ac溶液。给出了制备228Ra2-28Ac发生器的工艺流程。     

Identification of radiation treatment of wheat （Triticum aestivum. L）and rice （Oryza sativa. L） samples using thermoluminescence of contaminating minerals

Food irradiation is gaining popularity worldwide and this technology is important to improve quality and reduce the post harvest losses of food. Because of the rapid commercialization of irradiated foods throughout the world, compliance of different regulations relating to use of technology in different countries and demand of consumers for clear labelling of irradiated foods, there is need for the development of analytical methods to detect radiation treatment of food. Among several methods studied so far, thermoluminescence （TL） is an important method that can be used to find out the irradiation history of food that contain even a very minute amount of dust particles. In this study, the irradiated and unirradiated wheat and rice samples were analyzed using the TL method. The samples were purchased from the local market of Peshawar and irradiated to radiation doses of 0.5 and 1.0 kGy using Co-60 gamma irradiator at the Nuclear Institute for Food and Agriculture （NIFA）, Peshawar. The mineral contaminants were isolated by jet water, ultrasonic treatment, and density gradient. TL glow curves of the isolated minerals from irradiated and unirradiated samples were recorded between the temperature ranges of 50-500℃ using a TL reader. Generally, the glow curves for irradiated samples showed much higher TL intensities （TL1） than the unirradiated samples. The results were normalized by rerradiation of mineral samples to gamma-ray dose of 1.0 kGy followed by determination of the second glow curves （TL2）. The ratio of the area of first glow curve to that of second glow curve （TL1/TL2） was calculated for selected temperature intervals and compared with the recommended values for unirradiated and irradiated samples. Finally, the shapes of the glow curves for irradiated and unirradiated samples were also analyzed. On the basis of these results （comparison of TL-intensities, TL1/TL2 ratios and shapes of the glow curves）, all the irradiated and unirradiated samples of wheat and rice were unequivocally identified.     

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。     

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.     

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.     

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.     

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.     

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.