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。     

TCR分析技术作为辐射生物剂量计的可行性研究

以T淋巴细胞受体(TCR)为研究对象,探讨其作为辐射损伤生物剂量计的可行性.采集2名正常人外周静脉血,用不同剂量60Co γ射线照射,分离淋巴细胞,用流式细胞仪检测TCR突变频率,建立剂量效应回归方程.结果表明,受到60Co γ射线照射后,T淋巴细胞表面CD3、CD4表达情况发生改变,TCR突变频率在0～3 Gy剂量效应关系良好.     

电离辐射下双界面Si3N4/SiO2/Si的等离激元

用X光激发电子能谱(XPS)分析技术对Si3N4/SiO2/Si双界面系统经60Co电离辐照前后处于纯Si态的一级等离激元(定位于B.E. 116.95 eV)、处于SiO2态的一级等离激元(定位于B.E. 122.0 eV)和处于Si3N4态的一级等离激元(定位于B.E. 127.0 eV)进行了研究.实验结果显示:存在一个由Si3N4态等离激元和SiO2态等离激元构成的界面及由SiO2态等离激元和Si态等离激元构成的界面,在电离辐射的作用下,SiO2态-Si3N4态等离激元界面区中心向Si3N4态表面方向推移,同时SiO2态/Si3N4态等离激元界面区亦被展宽;电离辐照相当程度地减少位于SiO2态-Si态界面至Si衬底之间SiO2态的一级等离激元的浓度:同时偏置电场对SiO2/Si界面等离激元有显著作用.文中就实验现象以光电子能损进行了机制分析.     

辐射诱导Gadd45基因表达作为生物剂量计的实验室评估

为了考察电离辐照后人外周血中Gadd45基因表达的个体差异,评价Gadd45作为基因表达辐射生物剂量计的实用性,采集了27个健康人外周血进行60Co照射,提取白细胞mRNA,以β-actin作为内对照基因,建立了相对标准曲线法实时定量聚合酶链式反应(Polymerase chain reaction,PCR)方法,并以此方法探索辐照后Gadd45表达的剂量一效应关系.结果表明,0～2.5Gy剂量范围内,Gadd45的mRNA表达水平随照射剂量增加而上调,通过拟合建立了0～2.5Gy剂量范围内,Gadd45/β-actin相对表达量与照射剂量间的剂量-效应直线方程(y=0.216 0.258x,p<0.001,R2=0.650).发现Gadd45 mRNA表达水平在个体间存在一定差异,应用该剂量-效应直线方程,可以对0～2.5Gy照射剂量范围内的血液照射剂量作相对估算.     

表面增强拉曼的机制研究进展及其在生物医学中的应用

对表面增强拉曼（Surfaceenhanced Raman spectroscope，SERS）的增强机制研究进展，包括电磁增强机制和化学增强机制，以及具有高SERS活性的SERS探针进行综述。这种高活性的SERS探针可以用于单分子检测和单细胞成像。为了更好的应用于生物医学领域，SERS探针需要很好的生物兼容性。SERS探针能够提供详细的光谱信息，为多元分子诊断和体内拉曼成像提供了新的研究工具。     

基于核四极共振技术的邮件爆炸物检测系统

介绍了基于核四极矩共振(Nuclear Quadrapole Resonance,简称NQR)的爆炸物探测技术的原理和方法,并详细介绍了基于NQR技术的邮件爆炸物检测系统。该系统采用了直接数字合成技术定制激发脉冲序列,激发脉冲的相位、幅度和频率可实现程序精确控制。系统中采用了自动调谐技术保证探头只对感兴趣的频率点灵敏,集成了温度-频率关系曲线使得系统能够根据被测样品的温度自动修正激发频率。同时,在数据处理中引入加权算法抑制噪声干扰,提高了探测准确度。     

DNA折纸模板构建表面等离子体共振结构研究进展

介绍DNA折纸模板在组装金属纳米结构方面的最新进展,重点介绍利用DNA折纸术研究表面等离子体共振的工作,包括其在表面荧光增强和表面增强拉曼方面的应用,并展望了DNA折纸术在表面等离子体共振性质和结构关系研究中的发展趋势。     

振动扫描极化力显微技术原位研究乙醇在云母表面的吸附行为

用AFM成像技术的振动扫描极化力成像模式(VSPFM),在挥发性有机小分子乙醇的饱和气体氛围条件下,研究了云母表面吸附层对乙醇的吸附行为.通过对扫描探针针尖施加不同的偏压和梯度比较成像质量,探索挥发性两亲分子饱和气体氛围中亲水固体表面吸附层吸附行为的最优成像条件,对比实验发现当扫描探针的针尖施加偏压为AC 4-6V时,...     

Proton backscattering as a technique for light ion surface interaction studies in CTR materials investigations

Analysis of near-surface helium and hydrogen isotope depth profiles by a specialized proton backscattering technique has been demonstrated as a means to characterize the concentration, initial position, and subsequent migration behavior of all $\text{Z}$ atom species (except ¹H) in metals. The projected range $\text{(R}{}_{\mathrm{<mtext>p</mtext>}}\text{)}$ of helium implanted at 50 keV in Nb, V Ti and Cu has been measured and, for the latter two metals, has been found to agree with theoretical calculations within 100 Å (3%). Deuterium has also been detected and profiled (in Ti) using this technique. Detection sensitivity has been demonstrated at the 7 at % level for D in Ti and at the 0.5 at % level for ⁴He in Cu. In addition, surface and bulk distributions of carbon, oxygen and ³He have been profiled and, in principle, the depth distributions of tritium, ⁶Li, ⁷Li, Be, B, N, and F are also simultaneously resolvable if contained within the foil samples. The technique has been used to investigate the effect of radiation damage and in situ annealing on implanted helium profiles in copper. From these observations the mechanism for helium release from the end-of-range location has been delineated.     

Study of 3He+-bombarded palladium using nuclear magnetic resonance techniques

The nuclear magnetic resonance (NMR) from ion-implanted ³He atoms has been observed in ³He⁺-bombarded palladium. Two 1 μm palladium thin films, one on each side of a copper foil substrate, were bombarded at 75°C with 75 and 140 keV ³He⁺-ions to a fluence of $\text{～10}{}^{18}{}^3\text{He}{}^{\mathrm{+}}\text{/}\text{cm}{}^2$ for each energy. Spin-lattice ($\text{T}{}_1$) and spin-spin ($\text{T}{}_2$) relaxation times were measured at 10, 20, and 35 MHz in the temperature range 1–4K. The ³He nuclear relaxation data indicate that the implanted atoms after the 75°C bombardment are situated in small clusters within the Pd thin films.     

Investigation .on impurity transport using LBO technique

1. IntroductionIt is a common phenomenon in the tokamak devices that impurities have a concentrated trend towards the plasma central region. Impurity sourcesand its transport are very complicated, traditionalpassive methods can not be satisfied for the investigation of impurity transport. So transient perturbation methods have been developed and recognizedas the most appropriate for impurity transport measurement.The LBO technique is just the right transient perturbation method for this task…     

纯化氢用多孔不锈钢表面的修饰技术

采用浆料涂敷法,将纳米不锈钢粉末沉积在多孔不锈钢载体上,形成孔径依次减小的微孔不锈钢载体,其孔径约为200nm.在压差为0.1MPa时,其干空气渗透率约为200cm3·cm-2·min-1.再经溶胶-凝胶涂敷法,在此载体上沉积TiO2薄膜,其孔径约为100nm,此时的干空气渗透率,在压差为0.1MPa时,约为100cm3·cm-2·min-1.最后经化学镀技术,得到表面较光洁、合金化较完全的钯银合金膜,该膜在压差为0.1MPa、温度为300℃时的渗氢速率在标准状态下达35cm3·cm-2·min-1,氢氦分离因子达500.     

用同步光微束作激发源的PSS性能研究

用同步光微束作激发源,对所研制的平面晶体波长色散位置灵敏谱仪（PSS）性能进行了研究。结果表明,用LiF（200）晶体测得TiKα的能量分辨率达14．2eV,比Si(Li）探测器的能量分辨率好一个多量级;用Si(Li）观察不锈钢样品中的含CrKβ与MnKα两X线为一重叠的峰,而用PSS能清楚地分辨它们;对K2Cr2O7样品中Cr的探测限＜200μg/g和对一气溶胶样品中Ti的可检测量达10^-9-10^-9g量级。结果表明,随着实验条件的使PSS的探测限进一步降低,在同步光束线上用PSS开展高能量分辨的微量元素分析将是可行的。     

SHTV,as a technique for core calculation using spatial homogenization and temperature variation

The accuracy of static neutronic parameters in the nuclear reactors depends upon the determination of group constants of the diffusion equation in the desired geometry. Although several methods have been proposed for calculating these parameters, there is still the need for more reliable methods. In this paper a powerful and innovative method based on Spatial Homogenization and Temperature Variation (SHTV) of physical properties of a WWER-1000 nuclear reactor core for calculating the relative power distribution of Fuel Assemblies (FA) and the hot fuel rod, is presented. The method is based on replacing the heterogeneous lattices of materials with different properties by an equivalent homogeneous mixture of these material for determining the few group constants, while the effect of temperature variation in the fuel and coolant density along the axial core direction is considered. All calculations are performed using WIMS and CITATION codes. The obtained results are compared with the results of Final Safety Analysis Report (FSAR) prepared by the designer, and good agreement between the two results is shown.     

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。