在Logit-log直线回归中自动剔除“坏点”的一种方法

本文介绍一种在Logit-log直线回归中自动剔除“坏点”的方法、使用效果以及用蒙特卡罗法对该法与其他拟合方法的比较结果。     

微机多探头放免测定仪的数据处理

本文概要介绍FT-630型~(126)I放免测定仪的构成、数据处理功能梗概,以及RIA数据处理三大问题(标准曲线函数拟合、质量控制样品数据处理,精密度管理)的程序内容和与国内外典型产品功能的对比。     

Simulataneous analysis of reactivity of anilines in the hydrogen-isotope exchange reaction

In order to reveal the reactivity of a functional group in an aromatic compound having two substituents in the aromatic ring, the hydrogen-isotope exchange reaction （T-H exchange reaction） between tritiated water vapor （HTO vapor） and 4-amino-2-methylbenzenesulfonic acid （and 5-amino-2-methylphenol） were dynamically observed at 50℃ （and 70℃） in a gas-solid system. Consequently, the fact that the specific activity of the acid increased with time was obtained, and the T-for-H exchange reaction occurred. By applying the A＂-McKay plot method to the data observed, the rate constant of each functional group for the reaction was obtained. After the additive property of the Hammett＇s rule was applied to this work, the new substituent constants were obtained. From the above-mentioned, the following four items have been confirmed： （1） the reactivity of the functional groups can be dynamically analyzed, and the A＂-McKay plot method is useful to analyze the reactivity; （2） the additive property of the Hammett＇s rule is applicable to quantitative comparison of the reactivity of the functional groups; （3） the reactivity of the functional groups can be simultaneously analyzed by using the A ＂-McKay plot method in the T-H exchange reaction; and （4） the method used in this work is also useful for analyzing the reactivity of a certain material having some kinds of func- tional groups.     

An overview of reactivity initiated accident behavior of rock-like fueled pressurized water reactors

Reactivity initiated accident (RIA) analyses of plutonium rock-like oxide (ROX) fueled PWRs have been carried out with the point kinetics calculations. As a result, the analyses have shown a very severe transient behavior of the ROX fueled PWR, which is unacceptable without any improvement. It was also found that the RIA behavior of ROX fueled PWRs can be improved by increasing the negative fuel temperature coefficient (_f). For this improvement, the additives in the ROX fuel such as UO₂ and ThO₂ were considered, as well as a ROX assembly partial loading UO₂ core. With UO₂ additive, it was successful to have satisfying _f and RIA behavior of ROX fuel core, while the partial loading core must be further improved. Besides the ROX-PWR RIA analytical study, the actual behavior of the ROX fuel pin under RIA condition has been experimentally investigated at the Nuclear Safety Research Reactor (NSRR) of JAERI. Though the ROX fuel pin failure mechanism with fuel melting seems quite different from that of UO₂ pin with cladding melting, the ROX pin failure threshold was found to be roughly the same as that of UO₂ in terms of accumulated energy per unit fuel volume.     

锥束CT平行双丝法获取几何参数研究

几何参数的精确获取是锥束CT高质量成像的关键条件,因此锥束CT几何参数的精确获取是CT技术研究的重点之一。本文设计了一种易于制作、操作简便、集成化的模体,提出了锥束CT几何参数获取方法：平行双丝法。首先介绍了平行双丝法获取重要参数的原理及公式推导,通过仿真计算,论证了方法的鲁棒性。然后对该方法进行了实验验证,结果表明,平行双丝法具有参数获取精度高、鲁棒性好等优点,是一种较好的锥束CT几何参数获取方法。     

癌胚抗原试管固相免疫放射分析

报道以试管为固相载体，通过共价键的联结把两株癌胚抗原单抗结合的试管壁上，并标记另一株单抗，建立了癌胚抗原试管固相免疫放射分析法。该法具有较高的特异性和灵敏度，操作简便，重复性好，与液相放免法对照测定样品，两者结果密切相关。     

放射免疫分析与化学发光免疫检测应用对比及发展趋势

对比放射免疫分析技术（RIA）与化学发光免疫检测技术（CuA）在医学诊断中的发展和应用，结合RIA与CLIA免疫分析技术在临床应用情况，分析两种技术的发展现状、检测水平，并展望发展前景。RIA与CLIA均具有较高的精密度和灵敏度。RIA检测品种广泛、覆盖率高、种类齐全，适用于临床、科研教学，且收费标准低，可减轻患者经济负担，今后仍是重要发展方向之一。CLIA操作简便快速，无污染，仪器能实现自动化，具有一定竞争力。在相关政策扶持及本身技术改进的基础上，RIA将迎来快速发展时期。     

本底个值质控图在放免仪长期稳定性监控中的应用

在放免仪短期稳定性评价的基础上制作了本底个值质控图并应用于长期稳定性的监控。结果表明，该方法可作为放免仪长期稳定性考核、量化的一个手段。     

磁性颗粒固相分离剂的制备及其在放射免疫分析中的应用

本文研制了一种用于放射免疫测试的磁颗粒固相二抗分离试剂。将粗羊抗兔IgG二抗溶液纯化,采用氨基硅烷化修饰的磁性颗粒选择不同的酸度经戊二醛活化后,在不同的酸度下与纯化的二抗交联。同时进行了未活化磁性颗粒对二抗的吸附实验。放射免疫药盒测试结果为：未活化磁性颗粒固相二抗结合率低且极不稳定;活化后磁性颗粒固相二抗结合率高且稳定性好,并提高了放免药盒的灵敏度,标准曲线的相关性系数达0．9950。在液相分离法与磁性颗粒固相分离法的放射免疫测试比较中,其测得样品浓度的相关性也达到了0．9895。因此该磁性颗粒固相二抗是一个可用于放射免疫测试的通用分离试剂。     

Application of the Robust Design Concept for Fuel Loading Pattern

Application of the robust design concept for fuel loading pattern design is proposed as a new approach to improve the prediction accuracy of core characteristics. The robust design is a design concept that establishes a resistant (robust) system for perturbations or noises, by properly setting design variables. In order to apply the concept of robust design to fuel loading pattern design, we focus on a theoretical approach based on the higher order perturbation method. This approach indicates that the eigenvalue separation is one of the effective indices to measure the robustness of a designed fuel loading pattern. In order to verify the effectiveness of the eigenvalue separation as an index of robustness, numerical analysis is carried out for typical 3-loop PWR cores, and we evaluated the correlation between the eigenvalue separation and the variation of relative assembly power due to the perturbation of the cross section. The numerical results show that the variation of relative power decreases as the eigenvalue separation increases; thus, it is confirmed that the eigenvalue separation is an effective index of robustness. Based on the eigenvalue separation of a fuel loading pattern, we discuss design guidelines of a fuel loading pattern to improve the robustness. For example, if each fuel assembly has independent uncertainty on its cross section, the robustness of the core can be enhanced by increasing the relative power at the center of the core. The proposed guidelines will be useful to design a loading pattern that has robustness for uncertainties due to cross section, calculation method, and so on.     

放射性同位素免疫标记自动记录系统

文章叙述了放射性同位素免疫标记自动记录的原理以及整个系统设计在这个基础上提高放射性同位素免疫标记的准确性。     

固相亲和素制备技术及初步鉴定

将亲和素（Ａｖ）与牛血清白蛋白（ＢＳＡ）通过偶合试剂连接制成联接物，利用活化后ＢＳＡ的改性使联接物一步包被到疏水固上上形成更加易于定量的固相亲和素。实验鉴定证明，这种固相亲和素具有良好的生物活性，初步应用效果良好，可推广应用于生物素－亲和素系统的免疫分析。     

压水堆燃料棒三维热-力学性能的精细模拟

压水堆燃料棒工作在复杂的辐照、热和力学环境中,对其性能进行定量评估涉及多种复杂的物理现象。目前常用的燃料性能分析程序一般对结构采用简化的轴对称假设,对辐照肿胀、辐照蠕变和高温蠕变等物理现象以及辐照-热-力等物理场之间的耦合考虑并不充分。基于ABAQUS有限元求解框架,开发了压水堆燃料棒三维热-力学性能的模拟程序,利用程序对压水堆燃料棒进行了稳态分析,以及升功率和反应性引入事故两种瞬态分析。结果表明:辐照引起燃料致密化和肿胀对燃料温度变化有重要影响;芯块应变增加主要是由裂变产物肿胀引起的;芯块几何结构导致包壳应力集中发生在芯块间的交界面处;燃料棒功率的急剧变化会加快芯块表面破裂的进程;反应性引入事故会导致芯块从内部开始破裂,并会引发芯块-包壳的接触。     

放射免疫分析发展历史和建议

放射免疫分析是一类灵敏度高的超微量分析技术。它是现代免疫分析技术的基础。本文回顾放射免疫分析在中国的发展历史,阐述了近年放射免疫分析的现状、存在问题,并对今后如何更好地开展放射免疫分析提出几点建议。     

Modeling for Void Reactivity Effect by Subcooled Boiling under Reactivity Initiated Accident Condition of BWR

A simple mechanistic model is presented to evaluate the subcooled void reactivity effect under a Reactivity Initiated Accident (RIA) at cold critical condition of BWR. This model consists of a drift flux model for vapor velocity and a vapor mass conservation model with a term of vapor source on a heated wall, and it was incorporated into a homogeneous and equilibrium thermal-hydraulic code EUREKA-JINS. A sample analysis by this model showed that the subcooled void reactivity effect leads to reduction of the maximum fuel enthalpy by about 20 cal/g UO₂ in the case of RIA at cold critical condition. Though the reduced value is dependent on the reactor core condition, this result indicates the significance of subcooled void reactivity effect in the accident, while the effect can be neglected in the hot stand-by case where, at most, only 4 cal/g UO₂ is reduced for the maximum fuel enthalpy.     

Modification of thermal hydraulic code,THEATRe, with fuel rod behavior models and its application to reactivity-initiated accident (RIA)

During reactor operation, many complex changes occur in fuel rod which affects its thermal, mechanical and material properties. These changes also affect the reactor response to the transient and accident situations. Realistic simulation of fuel rod behavior under transients such as reactivity-initiated accident (RIA) is of great significance. In this study, thermal hydraulic analysis code THEATRe (Thermal Hydraulic Engineering Analysis Tool in Real-time) has been modified by addition of fuel rod behavior models for dynamic simulation of nuclear reactor. Transient changes in gas-gap parameters were taken into account by modeling the gas-gap behavior. Thermo-mechanical behavior of fuel rod is modeled to take into account the thermal, elastic and plastic deformation. To simulate RIA, point reactor kinetics model is also incorporated in the THEATRe code. To demonstrate the transient fuel rod behavior, AP1000 reactor is modeled and three hypothetical RIA cases are simulated. The RIA is considered at three different reactor power levels, i.e. 100, 50 and 1% of nominal power. The investigated parameters are fuel temperature, cladding stress and strain, fuel and cladding thermal conductivity and heat transfer coefficient in gas-gap. Modified code calculates the fuel rod temperatures according to updated fuel, clad and gas-gap parameters at the onset of steady-state operation and during the transient. The modified code provides lower steady-state fuel temperature as compared to the original code. Stress and strain analyses indicate that the hoop and radial strain is higher at high power locations of the fuel rod; therefore, gap closure process will initially occur in the central portion of the fuel rod and it should be given more emphasis in the safety analysis of the fuel rod and nuclear reactor during accidents and transients.     

主曲线方法在核电厂压力容器老化延寿中的应用

反应堆压力容器的压力-温度限值曲线(P-T限值曲线)方法是确保压力容器完整性的重要方法,在处理压力容器老化延寿问题中有着重要意义。传统的方法利用由t-R_TNDT曲线表征的材料准静态断裂韧性限值(K_Ic)绘制P-T曲线,这种方法不能直接测量材料辐照后的材料无延性转变温度的参考温度(R_TNDT),且过于保守。本文针对某核电厂压力容器,利用现有的辐照监督管数据估计50a延寿期末主曲线参考温度R_TT0,并采用ASME Code Case N629中的主曲线应用方法,计算寿期末的P-T限值曲线。与传统方法得到的P-T限值曲线相比,利用主曲线方法可以得到更大的运行窗口,能够提高设备的经济性。