氘在钛中的扩散行为

对以氘化钛形式吸附在金属钛中的氘的扩散行为进行了研究。样品经电子束加温至３４３℃，用＾４Ｈｅ－Ｄ前向反冲方法测量氘化钛分解后氘在钛表面和内部的浓度分布。由扩散方程求得吸附的氘化钛样品中氘的扩散系数和表面复合系数，并与通过向钛中注入氘的方法得到的结果进行了比较。     

氘在Ti-32Mo-5Nb合金中的行为

利用质子增强背散射和Ｘ射线衍射等方法,对氘在β相相的Ｔｉ－３２Ｍｏ－５Ｎｂ合金中的深度分布及Ｔｉ３２－Ｍｏ－５Ｎｂ合金吸氘前后的相结构等进行了分析研究。结果表明：该合金在低温阶段的吸氘速率明显现于纯钛,平均氘钛原子 ２．５,其中一部分氘与合金中的钛生成ＴｉＤ１．９７１,另一部分氘则固溶在Ｔｉ－３２Ｍｏ－５Ｎｂ合金中。     

氘化钛阴极的制备

根据串列加速器中铯溅射负离子源（ＳｏｕｒｃｅｓｏｆＮｅｇａｔｉｖｅＩｏｎｓｂｙＣｅｓｉｕｍＳｐｕｔｔｅｒｉｎｇ,ＳＮＩＣＳ）产生负氘离子的要求,制备了一种氘化钛阴极。它由１个圆柱形的铜阴极心和填满其中心孔的氘化钛溅射靶构成,作为溅射靶材料的氘化钛通过高纯度钛粉与氘进行化学反应制得。钛粉在适当的温度下进行真空处理,从而获得良好的化学活性,很容易与氘化合生成氘钛原子比为１．５的氘化钛（ＴｉＤ１．５）。     

氚示踪剂在土壤包气层实验中的应用

测定了土壤包气层中氚在天然条件和人工喷淋条件下的扩散系数，研究了氚示踪剂在黄土包气层中的迁移规律。实验结果表明，在华北地区黄土高原天然条件下，包气带中氚示踪剂以０．０３ｃｍ／ｄ速度迁移，纵向扩散系数Ｄｘ为０．１０ｃｍ＾２／ｄ；在２ｍ＾２实验坑中，以５ｍｍ／ｈ喷淋强度每天喷淋３ｈ的条件下，氚示踪剂以２．２７ｃｍ／ｄ的速度向下迁移，Ｄｘ为７．７５ｃｍ＾２／ｄ。     

GH903合金的离子注入表面改性研究

用离子注入、氧化和慢正电子束分析研究了ＧＨ９０３合金的氧化性能的改善与微观作用机理。注入的Ｃｒ＋．Ｙ＋的能量均为６０ｋｅＶ，注入的剂量分别由１ｘ１０１７．ｃｍ－２（Ｃｒ＋）、１ｘ１０１５Ｃｍ－２（Ｙ＋）和［１ｘ１０１５．ｃｍ－２（Ｙ＋）＋１ｘ１０１７·ｃｍ－２（Ｃｒ＋）］。结束显示，注入样品与未样品相比。氧化增重分别减少４．８％（注Ｃｒ＋）、２４．２％（注Ｙ＋）和３２．３％（注Ｙ＋＋Ｃｒ＋）。这表明合金氧化性能改善的作用机理主要是注入离子对样品浅表层内缺陷的填充与退火。同时，注入元素的化学性能和使样品表面更致密也起了重要作用。     

几种特殊靶的制备方法

文章了几种特殊靶的制备，包括７０ｍｇ．ｃｍ＾－２的自支撑Ｂｉ靶、Ｍｏ封窗膜、１５－５０μｇ．ｃｍ＾－２的自撑Ｓｃ靶（ＣＤ２）ｎ靶和７０μｇ．ｃｍ＾－２的自支撑Ｃｏ靶。     

DMPAQ分光光度法测定岩石中微量铀

研究了新试剂５－（４－二甲氨基苯偶氮）－８－羟基喹啉（ＤＭＰＡＱ）与铀（Ⅵ）的显色反应。在非离子型表面活性剂ＴｒｉｔｏｎＸ－１００存在和ｐＨ７．０—９．０缓冲介质中，铀（Ⅵ）与ＤＭＰＡＱ形成稳定的１∶２配合物，最大吸收波长为５１５ｎｍ，摩尔吸收系数κ＝５．６×１０３ｍ２／ｍｏｌ，铀的含量在０—２．０μｇ／ｍＬ范围内符合比耳定律。在适量的ＣｙＤＴＡ存在下，大多数常用离子不干扰测定。经ＴＢＰ萃取色层分离后，本法用于岩石中微量铀的测定。     

离子注入α－Al_2O_3陶瓷材料的表面改性研究

研究了α－Ａｌ２Ｏ３单晶注入Ｎ＋后的力学性能变化。结果表明，注入剂量为１×１０１７Ｎ＋／ｃｍ２时，Ａｌ２Ｏ３的显微硬度提高了９２％；注入剂量为３×１０１７Ｎ＋／ｃｍ２时，在Ａｌ２Ｏ３表面形成非晶层，导致表面软化，显微硬度只是基体的５０％左右．离子注入在样品表面产生了高达￣１１５０ＭＰａ的压应力，材料的断裂韧性的改善与此有关，实验亦发现Ｎ＋离子注入后Ａｌ２Ｏ３的断裂韧性提高了９５％左右．ＳＥＭ分析同样证明Ｎ＋注入ａ－Ａｌ２Ｏ３后，其表面力学性能确实有所改善。     

高能（MeV级）氧离子注入本征型GaAs的电性能及注入损伤退火行为的研究

在本征型ＧａＡｓ中注入２．０ＭｅＶ（剂量１．０×１０＾１５／ｃｍ＾２）＋２．９ＭｅＶ（剂量１．１×１０＾１５／ｃｍ＾２）的＾１６Ｏ，使氧在约１．５－２．５μｍ之间形成均匀分布。注入样品分别经４００－８００℃、１５ｍｉｎ热退火后的电阻率测量表明，经５００℃和６００℃退火后的样品具有高的电阻率（～１０＾８Ω·ｃｍ）；而当退火温度进一步升高时，其电阻率逐渐下降，并具有ｐ型导电行为。沟道ＲＢＳ分析表明，当     

钛薄膜氢化及热释放特性研究

用高能离子非卢瑟福背散射分析和前向反冲分析方法研究了Ｃ、Ｏ污染对Ｔｉ膜的吸放氢能力的影响。实验观测到,１．２６＊１０＾１６ｃｍ＾－２和２．６＊１０＾１６ｃｍ＾－２Ｏ的双重污染可使Ｔｉ膜在３００ｎｍ的范围内存在着低的Ｈ浓度区,使氢的热释放温度大大提高。     

Reactivity temperature coefficients for the HEU and LEU fuel of the MNSR reactor

Analysis of the Reactivity Temperature Coefficients of the Miniature Neutron Source Reactor (MNSR) for normal and accidental conditions (above 45 °C) using HEU-UAl₄ and the LEU: U₃Si, U₃Si₂ and U9Mo fuel were carried out in this paper. The Fuel Temperature Coefficient (FTC), Moderator Temperature Coefficient (MTC), and Moderator Density Coefficient (MDC) were calculated using the GETERA code. The contribution of each isotope presented in the fuel cell was calculated for the temperature range of 20 °C–100 °C at the beginning of the core life. The average values of the FTC for the UAl₄, U₃Si, U₃Si₂ and U9Mo were found to be: −2.23E-03, −1.85E-02, −1.96E-02, −1.85E-02 mk/°C respectively. The average values of the MTC for the UAl₄, U₃Si, U₃Si₂ and U9Mo were observed to be: −8.91E-03, −1.24E-04, −4.70E-03, 2.10E-03 mk/°C respectively. Finally, the average values of the MDC for the UAl₄, U₃Si, U₃Si₂ and U9Mo were observed to be: −2.06E-01, −2.03E-01, −2.04E-01, −2.03E-01 mk/°C respectively. It's found also that the dominant reactivity coefficient for all types of fuel is the MDC.     

Calculation and measurement of migration coefficient of radon under laboratory conditions

Under laboratory conditions （i.e. a sealed system in which the temperature may vary according to air temperature）, the migration of radon in upward, downward and horizontal directions has been investigated. After a period of accumulation, the spatial distribution profile of radon was drawn on the basis of the experimental data. The profile showed whorl-shape with bigger ends. The longer the accumulation time, the bigger the whorl end, and the higher the radon concentration is. By fitting the experimental data by least-square statistical method, we find that the distributions of radon follow negative exponential functions in the upward, downward and horizontal directions. However, exponents for the three directions are not exactly identical. The upward migration is more effective than the downward one and both upward and downward migrations are more effective than the horizontal one.     

聚合物膜氡渗透系数的测定

为选出适用于我国江门中微子实验的氡屏蔽聚合物膜材料,研究了稳态时利用液体闪烁计数器测定聚合物薄膜氡渗透系数的装置和方法。实验测得了尼龙膜和聚乙烯膜的氡渗透系数并与文献中的数值范围进行了对比,测定结果表明,常用研究材料中尼龙膜的氡渗透系数较低,对降低氡浓度有显著效果。此外实验验证了薄膜氡渗透系数测定的主要影响因素,包括简化计算的方法、系统达到稳态的时长、环境湿度和温度等,并对进一步标准化测定聚合物薄膜的氡渗透系数提出了参考意见。     

Chemical diffusion coefficient calculation of U3+ in LiCl-KCl molten salt

Self-diffusion coefficient denotes the intrinsic diffusion of elements without the chemical gradient; generally, it is different from the chemical diffusion coefficient that is used in Fick's law. However, the self-diffusion coefficient can be converted to the chemical diffusion coefficient by considering the concentration-dependent activity coefficient of solute. In this study, the multiple time origins method was applied to calculate the self-diffusion coefficient of U³⁺ in LiCl-KCl eutectic salt at different temperatures and concentrations. The chemical diffusion coefficient was obtained based on the calculated results and thermodynamic theory. Calculated results show that self-diffusion coefficient decreases with concentration however chemical diffusion coefficient indicates to change little initially but appears to increase followed by decrease later within the concentration range of 0–3 at%.     

Diffusion characteristics of HTO and 99TcO4- in compacted Gaomiaozi (GMZ) bentonite

The characteristics of diffusion are essential to the transport of radionuclides through buffer/backfill materials, such as bentonite, which are commonly found in waste repositories. This study used through-diffusion techniques to investigate the diffusion behavior of HTO and ~(99)TcO_4~- on GMZ bentonite of various densities. Diffusion rates were calculated by measuring the diffusion coefficients(De, Da), plotting breakthrough curves and interpreting experiment data. The apparent and effective diffusion coefficients of HTO ranged from(1.68 ± 0.40) 9 × 10~(-11) to(2.80 ± 0.62) 9 × 10~(-11) m~2/s and from(4.61 ±1.28) 9 × 10~(-12) to (16.2 ± 2.50) 9 × 10~(-12) m~2/s, respectively.The apparent and effective diffusion coefficients of~(99)TcO_4~-ranged from(5.26 ± 0.16) 9 × 10~-12to(7.78 ± 0.43) 9× 10~-12m~2/s and from(1.49 ± 0.002) 9 × 10~(-12) to(4.16 ±0.07) 9 × 10~(-12) m~2/s, respectively. The distribution coefficients of HTO and~(99)TcO_4~-ranged from(0.70 ± 0.12) 9× 10~(-2) to(1.36 ± 0.53) 9 × 10~(-2) mL/g and from(1.12 ±0.06) 9 × 10~(-2) to(5.79 ± 2.22) 9 × 10~(-2) mL/g, respectively.The Deand Kdvalues were shown to decrease with an increase in the bulk dry density of compacted bentonite. Our results show that HTO and ~(99)Tc could be considered nonsorbent radionuclides. The data obtained in this studyprovide a valuable reference for the safety assessment of waste repositories.     

Measurements of the isothermal, power and temperature reactivity coefficients of the IPR-R1 TRIGA reactor

The aim of this paper is to present the experimental results of the isothermal, power and temperature coefficients of reactivity of the IPR-R1 TRIGA reactor at the Nuclear Technology Development Center - CDTN in Brazil. The measured isothermal reactivity coefficient, in the temperature range measured, was −0.5 ¢/°C, and the reactivity measurements were performed at 10 W to eliminate nuclear heating. The reactor forced cooling system was turned off during the measurements. When the reactor is at zero power there is no sensible heat being released in the fuel, and the entire reactor core can be characterized by a single temperature. The power coefficient of reactivity obtained was approximately −0.63 ¢/kW, and the temperature reactivity coefficient of the reactor was −0.8 ¢/°C. It was noted that the rise in the coolant temperature has contributed only with a small fraction to the observed negative effect of the reactivity. The power defect, which is the change in reactivity taking place between zero power and full power (250 kW), was 1.6 $. Because of the prompt negative temperature coefficient, a significant amount of reactivity is needed to overcome temperature and allow the reactor to operate at the higher power levels in steady state.     

花岗岩单裂隙中核素迁移的研究Ⅰ.弥散系数的测定

设计并建立了花岗岩单裂隙中放射性核素迁移的穿透实验装置。用１２５Ｉ和ＨＴＯ通过单裂隙的穿透实验,测定了它们在花岗岩单裂隙中的弥散系数和表面阻滞系数。     

裂片核素在岩石中的迁移研究 Ⅰ.核素~(75)Se在花岗岩和石灰岩中的扩散行为

高水平放射性废物处置的主要方法是深埋在地质岩石中。在研究放射性核素随地下水穿过岩石缝隙网的迁移中,扩散法起着重要的作用。本文测定了~(75)SeO_3~(2-)在花岗岩和石灰岩(取自北京郊区)中的扩散系数,并详细叙述了实验技术和分析方法。     

5MW THR主换热器设计

文中叙述了5MW THR 主换热器的设计特点,给出了主换热器壳侧的放热系数和总阻力系数。     

定位架对元件表面传热的影响

采用传热试验与传质试验二种方法测定了定位架对元件表面传热的影响,测定了传热系数与传质系数沿轴向的变化,并将传热试验与传质试验的结果进行了比较。