辐射制备AA-AM型保水剂的性能研究

采用⁶⁰Coγ射线辐射引发聚合合成AA-AM（丙烯酸-丙烯酰胺）共聚型保水剂。对所制备的吸去离子水为2.414kg/g的保水剂的吸盐水（0.9%NaCl溶液）性能、吸人工尿液性能及反复吸水能力进行研究，实验考察了保水剂粒径对吸水速率、吸水率的影响。研究结果表明：AA-AM型保水剂具有优良的综合吸液性能，大粒径保水剂的吸水率和反复吸水能力皆比小粒径保水剂的大。     

丙烯酸-丙烯酰胺共聚高吸水性树脂的紫外聚合及其性能研究

本论文在无交联剂条件下以丙烯酸、丙烯酰胺和氢氧化钠为原料利用高压紫外汞灯辐照引发聚合高吸水性树脂丙烯酸(AA)-丙烯酰胺(AM)共聚物。考察中和度、光照时间、单体含量、聚合物粒度等因素对共聚AM-AA吸液性能的影响。获得了最佳的试验条件,并在最佳试验条件下合成了共聚物。其吸水率(去离子水)为3062g/g,吸生理盐水(0.9%NaCl水溶液)率为241.6g/g,吸自来水率232.8g/g,吸人工尿率为76.6g/g,吸人工血率为367g/g。     

γ射线引发甲基丙烯酸十二酯乳液聚合及其吸油性能的研究

讨论了以OP-10、十二烷基苯磺酸钠为乳化剂，γ射线引发甲基丙烯酸十二酯与少量N-羟甲基丙烯酰胺和丙烯酸乳液聚合制备高吸油性树脂。分别采用红外，SEM和TG表征了聚合物的成分、结构和热性能。SEM显示乳液胶束粒子尺寸均一，粒径约为170nm。聚合物在300℃以下时热稳定性良好。研究了反应条件如吸收剂量、剂量率、固含量、N-羟甲基丙烯酰胺和丙烯酸用量等对聚合物的吸煤油性能的影响。聚合物对煤油、氯仿、二甲苯的最大饱和吸油率（g儋）分别为18．1、19．5和15．3。     

预辐射接枝法制备FEP-g-PSSA/AA膜

采用γ射线预辐射接枝方法制备了FEP—g—PSSA／AA膜，反应制得的接枝膜是一种含氟磺酸型质子交换膜。系统研究了影响接枝反应的阻聚剂用量、膜的厚度、单体摩尔比及总摩尔浓度变化等因素。结果表明，丙烯酸（Acrylic acid，AA）与苯乙烯磺酸钠（Sodium styrene sulfonate，SSS）对全氟乙丙烯（Polytetranuoroethyleneco-hexanuoropropylene，FEP）的接枝率几乎不受膜厚度变化的影响，而且全氟乙丙烯（FEP）辐照后放置三个月再进行接枝反应，接枝率也几乎没有变化。     

辐射合成AA/PEGMA嵌段共聚高吸水性树脂

以聚乙二醇 (PEG)为原材料 ,通过酯化反应制备了双端活化的大单体聚乙二醇双马来酸单酯 (PEGMA) ,FT -IR证实了产物的结构特征。然后利用它与另一单体丙烯酸 (AA)进行辐射引发共聚得到了聚 (AA -b -PEGMA)嵌段共聚高吸水性树脂 ,并对影响其性能的合成条件如单体浓度、比例、辐照剂量等进行了研究。发现该高吸水性树脂具有优良的吸水性能 ,其吸水率高达3.786× 10 3,吸盐水 (0 .15mol/L ,NaCl)可达 0 .176× 10 3,并用FT -IR和SEM表征了产物的结构特征。     

丙烯基类单体-壳聚糖共聚物水凝胶的辐射制备及性能研究

以壳聚糖、丙烯酰胺（AM）和二甲基二烯丙基氯化铵（DMDACC）为原料,N,N-亚甲基双丙烯酰胺（MBA）为交联剂,经^60Co γ-射线辐照,制备了丙烯基类单体一壳聚糖共聚物水凝胶,并研究了MBA的用量对丙烯基类单体一壳聚糖共聚物水凝胶吸水性能和保水性能的影响。结果表明,在吸收剂量为2kGy的条件下,MBA用量较低时,随着MBA用量的提高,水凝胶的平衡吸水率反而下降;而MBA用量较高时,水凝胶的平衡吸水率受MBA用量的影响较小;凝胶吸水率随着溶胀时间的延长而增加;水凝胶在溶胀初期的溶胀动力学可用non-Fickian扩散定律来描述：随着交联剂MBA用量的逐渐增加,水凝胶的初始失水率逐渐增大,而最大失水率逐渐下降。     

金属镱低压吸氘研究

在真空系统中的氘压低于0．1MPa条件下研究了金属镱的吸氘性能，并对不同原子比的氘化物的物相进行了分析。在常压、300℃下，金属镱吸氘不明显；400℃时，金属镱经较长时间活化后吸附一定量的氘；500℃时，镱升华。400℃时的吸氘实验结果表明：从活化至开始吸氘直至吸附平衡需很长时间；氘／镱原子比的高低与吸氘时间有关，饱和吸时的原子比最大为2．00；金属镱为面心立方（fcc）结构，a0=0.5492nm。具有不同原子比的氘化镱的X射线衍射（XRD）分析结果显示：氘化镱有2种结构，即面心立方结构（a0=0.524nm）和正交结构（a0=0.588nm、b0=0.358nm、c0=0.678nm）；金属镱吸氘后，立方结构氘化镱晶格常数及晶胞体积均发生收缩现象，收缩率分别约为4％和11％。正交结构氘化镱晶本积收缩约14％。     

大粒径疏水催化剂的制备及氧化氚氢(HT)的性能研究

用两段聚合法及溶出致孔剂法分别制备了多孔大粒径苯乙烯－二乙烯基苯和聚四氟乙烯疏水担体;在此基础上,用浸渍法制备了２种大粒径铂疏水催化剂,在室温下研究了它们催化氧化ＨＴ（Ｈ２）的动力学和疏水性能。     

预辐照接枝丙烯酸与丙烯酰胺改性苎麻纤维及其吸附铜离子性能研究

将丙烯酸(AA)与丙烯酰胺(AM)通过预辐照接枝在苎麻纤维上,通过协同作用提高其接枝率,并研究了其对Cu2+的吸附性能。傅里叶红外光谱(FT-IR)对苎麻纤维表面分析结果显示,AA及AM成功接枝在苎麻纤维上,吸收剂量为35kGy时,接枝率可达151%(AA与AM浓度比为1∶1)。对Cu2+的吸附实验结果表明,接枝后的苎麻纤维在吸附反应初期,Cu2+吸附量迅速增加,20~30min增加速度变缓,30min后趋于饱和;随着温度升高,吸附量迅速增加,但温度高于40℃后,吸附量不再增加;吸附量随初始Cu2+浓度的增加而增大,在初始浓度为1 000mg/L的Cu2+溶液中,苎麻纤维的Cu2+吸附量可达14.40mg/g。     

Ti-Mo合金吸氢动力学的同位素效应

为寻找一种价格低廉、分离性能优良的氢同位素分离材料来替代金属Pd,对Ti-Mo合金的氢同位素效应进行研究。采用磁悬浮熔炼方法制备5种不同组成的TiMox（x=0.03、0.13、0.25、0.50、1.00,Mo/Ti原子比）固溶体合金,用定容变压法测试了250～650℃范围内的吸氘动力学性能。结合前期吸氕动力学的研究结果可知,在250～650℃范围内,合金的平衡吸氕量略大于合金的平衡吸氘量。Mo含量小于1.00,在低温（250～450℃）下,合金的吸氘表观活化能均为负值。高温（450～650℃）下,合金的吸氘表观活化能大于吸氕表观活化能,与钛吸氢同位素动力学效应保持一致。     

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.     

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.