含硅丙烯酸酯在紫外光固化涂料中的应用研究

合成了氨基硅油改性丙烯酸酯(AMPA),将其与PTFE微蜡粉、PE改性PTFE微蜡粉作为表面改性剂加入到紫外光(UV)固化涂料中,用红外光谱对固化前后进行了表征,研究了其对UV固化膜耐磨性的影响,考察了固化膜表面元素的富集现象,并测试了固化膜表面水接触角和光泽度的变化。研究结果表明,表面改性剂具有自润滑的作用,少量加入即能显著地提高固化膜的耐磨性,含硅改性丙烯酸酯(AMPA)的质量分数由0.0%增加到1.0%时,光固化膜耐磨测试质量损失由22.8mg下降到9.2mg,表面水接触角由43.3o增加到100.3o,表面光泽度由113.5°下降到95.5°。     

固化氛围对丙烯酸酯紫外光固化材料表面性能的影响

在空气或氮气氛围下对同样配方的光敏树脂进行紫外光固化,固化膜的表面能测定表明,空气中固化材料的表面能大于氮气中固化材料.固化膜的元素分析和衰减全反射-傅立叶变换红外光谱(Attenuated total reflectance-Fourier transform infrared spectroscopy,ATR-FTIR)分析表明,氧阻聚反应并未导致空气下固化的材料中氧含量的明显变化,其红外谱图中未见有过氧基团的吸收峰,但其表面富集有较多的吸电子基团;而氮气下固化的材料表面存在较多的碳碳单键.X射线光电子能谱(X-ray photoelectron spectroscopy,XPS)分析表明,不同的固化氛围使材料表面C1s和O1s原子结合能产生差异.说明固化氛围影响固化速率,使固化过程中固化膜组成分布或聚集态密度产生差异,最终使固化层的表面化学组成乃至表面能存在差别.     

聚氨酯改性丙烯酸环氧单酯的光-热固化性能

合成了聚氨酯改性丙烯酸环氧单酯,树脂分子结构中同时具有光固化基团(双键)和热固化基团(环氧基团).用FTIR表征了光-热固化过程特征吸收峰的变化.研究了不同的稀释剂、热固化剂对光固化和光—热混杂固化的凝胶率、吸水率、力学性能和热性能的影响,结果表明:光固化膜的凝胶率低于89％,而光—热混杂固化膜的凝胶率在97％左右.在...     

碱溶性感光树脂的结构与性能的研究

合成了３种类型、４种配比、５种不同结构的碱溶性感光树脂,研究了碱溶性和光固化速度。随着树脂与马来酸酐配比增大,树脂的碱溶性变好,光固化速度变快,当配比大于１：０．７时,树脂具有良好的碱显影性能。用酚醛环氧丙烯酸型碱溶性树脂制备光成像抗蚀油墨,具有较佳的碱显影性能。     

丙烯酸聚氨酯涂料辐射固化的研究

本涂料所用的树脂是丙烯酸羟丙酯,聚丙二醇和甲苯二异氰酸酯的反应物。本反应物经某些丙烯酸酯稀释,配制成电子束固化涂料。将此涂料涂布于木材表面,于氮气氛下,以3Mrad的总剂量经电子静电加速器辐照。固化后测得涂膜性能优良,作为木器表面涂料可得到令人满意的结果。     

光引发剂对紫外光固化胶粘剂性能的影响

制备了以IR651和IR1700为引发剂的紫外光(UV)固化胶粘剂，研究其感光性能和粘接性能。在曝光30s后，以IR1700为引发体系的UV固化胶粘剂的剪切强度可达8．3MPa，而引发体系为IR651的剪切强度仅为0．6MPa。比较了两种光引发剂时的感光性能，IR1700体系的感度值为2．85mJ/cm^2，而IR651的为4．03mJ/cm^2。经深度固化研究表明，IR1700具有深度光固化的优异性能。     

利用低能自屏蔽电子帘式加速器进行木器表面涂料辐照固化的研究

本文初步描述了利用低能自屏蔽电子帘式加速器固化木器涂料和石膏板表层涂料的生产工艺。讨论了电子束固化过程中的质量控制,诸如表层涂料的涂布技术,涂层厚度对表面性能的影响,电子束辐照场下的剂量值与剂量分布等。合成了作为EB涂料主要成分的不饱和聚酯树脂。比较了几种不同种类的EB涂料的固化条件并且对固化后涂层性能作了表述。     

疏水孔对旋叶分离器分离效率影响研究

为提高旋叶分离器中气-液混合物的分离效率,针对内筒具有正三角形排布疏水孔的旋叶分离器开展空气-水性能试验和计算流体动力学（CFD）数值模拟研究,分析每一排疏水孔分离水比例变化规律和疏水孔布置高度对分离性能的影响。研究结果表明,当空气表观速度较低（≤14.4 m/s）时,每一排疏水孔分离水比例随着内筒高度的升高呈先下降后增加的趋势;当空气表观速度较大（>14.4 m/s）时,每一排疏水孔分离水比例随内筒高度升高呈单调下降的趋势。研究对比了第1排疏水孔布置距离旋叶分别是0.8倍、1.0倍、1.2倍内筒直径3种位置时分离性能的变化, 结果表明当空气表观速度较低（< 12.9 m/s）时,疏水孔位于1.2倍内筒直径位置时旋叶分离效率最高;空气表观速度较高（≥12.9 m/s）时,疏水孔位于0.8倍内筒直径位置时旋叶分离效率最高。      

水性丙烯酸树脂的合成和UV固化研究

合成了一种新型的、可射线固化的水性丙烯酸树脂,采用该树脂和各种辅助成分配制成水性涂料。研究了在合成过程中异氰酸酯基含量（ＮＣＯ％）的变化以及该树脂的水稀释曲线。同时研究了辐照时间、距离,光引发剂的种类,光敏助剂以及活性稀释剂对交联程度的影响,得到了性能优良的涂膜。     

辐照─应变法研究光固化体系活性

利用Ｎ－１２１型ＵＶ固化测试仪测定光固化体系的固化进程，研究了活性稀释剂的官能度、光引发剂浓度及光照强度等对光固化速度的影响。     

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。     

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%。     

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.     

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.