核电厂智能诊断方法研究的进展

文章评述神经网络、模糊逻辑和专家系统3种典型的智能方法在核电厂(NPP)运行状态监测和故障诊断中的应用研究进展.分析了基于神经网络(ANN)、模糊逻辑和专家系统的核电厂运行状态监测和故障诊断方法的研究状况及其特点.探索了核电厂智能诊断方法应用研究的发展趋势.分析表明:基于模糊逻辑和专家系统的核电厂智能诊断方法的研究成果相对较少;核电厂智能诊断方法研究主要集中在基于神经网络的状态监测与故障诊断方面;多种智能诊断方法的结合、神经网络与其它方法的结合,以及基于多神经网络的核电厂运行状态监测和故障诊断方法研究是核电厂智能诊断方法研究的重要发展趋势.     

ICRU 94号报告急性照射后个体剂量的初始阶段评估方法

国际辐射单位与测量委员会(ICRU)94号报告描述了用于急性辐射照射后个体剂量评估的方法。主要方法包括生物剂量测定和物理剂量学技术,而其他补充方法是生物测量技术、中子活化和辐射场映射方法。生物剂量测定方法包括染色体测定、细胞分裂阻断微核测定、荧光原位杂交易位分析、染色体缩合和γ-H2AX测定技术。新兴技术包括基于RNA表达、基于蛋白质和基于代谢组学的检测。     

地电化学提取铀及其它金属的研究

地电化学提取法是地电化学勘探方法的一种,是新发展起来的找贱金属、贵金属、稀有金属和一部分非金属矿产的直接深部找矿方法,是物探电法和化探结合在一起的物理化学方法,尤其是对寻找金矿床更有其独到之处。本文主要介绍该方法的简易原理和找金、铀、铜、铅、镍、锡等矿床的效果,同时也简述了该方法所使用的仪器设备。     

ICRU 94号报告急性照射后个体剂量的初始阶段评估方法北大核心CSCD

国际辐射单位与测量委员会(ICRU)94号报告描述了用于急性辐射照射后个体剂量评估的方法。主要方法包括生物剂量测定和物理剂量学技术,而其他补充方法是生物测量技术、中子活化和辐射场映射方法。生物剂量测定方法包括染色体测定、细胞分裂阻断微核测定、荧光原位杂交易位分析、染色体缩合和γ-H2AX测定技术。新兴技术包括基于RNA表达、基于蛋白质和基于代谢组学的检测。     

人的可靠性分析方法比较

选择了THERP、ASEPHRA、HCR、HEART、SLIM、CREAM、ATHEANA等7种常用的人的可靠性分析（HRA）方法进行比较,提出了HRA方法比较的12个标准,并用这些标准得到了HRA方法的比较结果。方法比较的标准和依据来自HRA方法的理论基础、模型、分析过程、具体实践,以及文献调研和专家判断。     

核电站先进反应堆评价系统的决策方法研究

为开发先进反应堆评价系统,对层次分析加权求和方法、模糊综合决策方法、模糊Borda数方法等综合评价决策方法进行了详细研究,并结合评价结果,对各种评价方法进行了分析、比较和总结。     

微观燃耗方程的求解算法比较与性能分析

燃耗方程的求解是燃耗计算的核心。常见的算法包括泰勒方法、Pade方法、子空间方法、切比雪夫有理近似方法和龙格库塔法等。通过数值实验,对每种算法在精度、效率、稳定性方面进行分析比较。结果表明：子空间方法、泰勒方法在计算效率方面具有优势;计算精度及稳定性方面,泰勒方法和Pade方法均占优势。综合考虑,泰勒方法在3个方面均表现突出,可作为燃耗计算的优选算法。     

小样本成败型设备可靠性评估方法

小样本、高可靠性成败型设备可靠性评估是核工程和航天工程领域经常遇到的难题.本文系统地分析了若干可靠性评估方法,包括Bayes方法、改进Bayes方法以及Bayes网络方法,同时结合相应的仿真算例说明了方法的应用,最后对成败型设备可靠性评估问题提出了一些结论和建议.     

同一物理量观测值的处理

在核数据评价和测量中,经常遇到同一物理量观测值的处理。当这些数据在统计学上一致时,很容易用统计方法处理,但存在系统误差时,处理就很困难。本文提出了一个普遍适用的方法。根据这个方法,由给出的系统误差的协方差矩阵,可计算平均值和它的误差。加权平均值、算术平均值、内误差、外误差和算术平均误差只是这个方法的特殊情况。给出的实例表明,这个方法是合理的。     

核设施用去污技术

介绍了核设施放射性污染去除方法（如泡沫法、凝胶法、氧化还原处理法等化学方法和真空处理法、磨料喷射法、高压水喷射法等物理方法）,分析了各种去污方法的优缺点。最后针对我国去污工作的现状,提出了一些建议。     

Experimental Study of the Atomic and Molecular Processes Related to Plasma Detachment in Steady-State Divertor Simulator MAP-II

Atomic and molecular processes relevant to the volumetric recombination phenomena were investigated in a linear divertor plasma simulator MAP-II. Volumetric recombination is induced in He plasma by puffing of He or H2. In the He puffing case, the reduction of the ion flux is dominated by the electron-ion recombination. In the H2 puffing case, however, it is dominated by the molecule-assisted recombination (MAR), which is characterized by the disappearance of the Helium Rydberg spectra and by the existence of the hydrogen negative ions. Current achievement and the future prospect are described.     

氦-3回路的研究与设计

为使中国先进研究堆（CARR）具备开展压水堆燃料瞬态试验的能力,本工作对氦-3回路进行研究与初步设计。文章描述了氦-3回路的工作原理、设计参数和工艺流程。研究结果表明,氦-3回路能够快速、均匀、灵活地调节试验燃料棒的功率,是CARR实现压水堆燃料功率瞬态变化的优选方案。     

Fuel retention study in fusion reactor walls by micro-NRA deuterium mapping

Nuclear Reaction Analysis (NRA) with a ³He ion beam is a powerful analytical technique for analysis of light elements in thin films. The main motivation for ³He focused beam applications is lateral mapping of deuterium using the nuclear reaction D(³He,p)⁴He in surfaces exposed to a tokamak plasma, where a lateral resolution in the μm-range provides unique information for fuel retention studies.At the microprobe at the Jo?ef Stefan Institute typical helium ion currents of 300 pA and beam dimensions of 4 × 4 μm² can be obtained. This work is focused on micro-NRA studies of plasma-facing materials using a set-up consisting of a silicon partially depleted charge particle detector for NRA spectroscopy applied in parallel with a permanently installed X-ray detector, an RBS detector and a beam chopper for ion dose monitoring. A method for absolute deuterium quantification is described. In addition, plasma-deposited amorphous deuterated carbon thin films (a-C:D) with known D content were used as a reference.The method was used to study deuterium fuel retention in carbon fibre composite materials exposed to a deuterium plasma in the Tore Supra and TEXTOR tokamaks. The high lateral resolution of micro-NRA allowed us to make a detailed study of the influence of topography on the fuel retention process. We demonstrated that the surface topography plays a dominant role in the retention of deuterium. The deep surfaces inside the castellation gaps showed approximately two orders of magnitude lower deuterium concentrations than in areas close to the exposed surface.     

Interatomic potentials for simulation of He bubble formation in W

A new interatomic pair potential for W–He is described, which includes a short range modification to the Ackland–Thetford tungsten potential. Molecular dynamics simulations using these potentials accurately reproduce ab initio results of the formation energies and ground state positions of He point defects and self interstitial atoms in W. Simulations of larger He–vacancy clusters with up to 20 vacancies and 120 He atoms show strong binding of both He and vacancies to He–vacancy clusters for all cluster sizes. For small clusters, the qualitative agreement with ab initio results is good, although the vacancy binding energy is overestimated by the interatomic potential.     

（e,2e）实验的符合测量系统

研制成功的（ｅ，２ｅ）实验的符合测量系统由快时间道和慢位置道组成。以该系统四个慢符合道的位置信息电荷脉冲信号和快符合道中的时间信息作为五个参数，测得了电子碰撞Ｈｅｌｓ的符合时间谱和电离能谱。     

ELASTIC RECOIL DETECTION ANALYSIS OF LIGHT ELEMENTS IN THIN FILMS USING 35 MeV~(35) Cl~(6+) BEAM

In this paper, an elastic recoil detection analysis method is described using 35 MeV ~(35)Cl as incident ions. This method can determine and profile simultaneously H, D, He, C and O or in the other case, H, C, N and O. The depth resolution for the elements heavier than He is better than 20 nm. It has been applied to study the Co/Si and TiN thin films, and the depth profiles of He implanted in monocrystal silicon.     

闪烁法测量伴随~3He粒子的中子飞行时间谱仪

在D(d,n)~3He反应中,目前常采用Si(Au)面垒型半导体探测器测量伴随粒子。半导体探测器的能量分辨率高,是这种方法的优点,但由于~3He粒子能量低,电荷灵敏前置放大器所给出的~3He信号幅度小,容易受到噪声以及干扰信号的影响,因而谱仪的时间分辨性能不容易做得很好。比如Ohio大学的中子飞行时间谱仪,出射~3He粒子的能量为650     

3He对 LaNi5储氚性能影响的第一性原理

基于第一性原理的密度泛函理论研究LaNi5储氚过程中T衰变为3He前后晶体的几何结构和能量变化,计算得到了在平衡态时3He在储氚的LaNi5合金中的最可几占位为八面体位置和十二面体位置。进一步分析了衰变前后的材料能带结构、电子态密度(DOS)分布。氦的惰性不溶使LaNi5合金晶格膨胀和电子态密度分布发生变化是影响LaNi5储氚过程中坪台压降低、斜坪增大的主要原因。在氦原子周围形成的深势阱是形成氚尾效应的主要原因之一。     

Calculation of the substitutional fraction of ion-implanted He in an α-Fe target

Ion-implantation is a useful technique to study irradiation damage in nuclear materials. To study He effects in nuclear fusion conditions, He is co-implanted with damage ions to reproduce the correct He/dpa ratios in the desired or available depth range. However, the short-term fate of these He ions, i.e. over the time scales of their own collisional phase, has not been yet unequivocally established. Here we present a computational study of the short-term evolution of He implantation in an Fe substrate at 700 K to approximate the conditions encountered in dual ion-implantation studies in ferritic materials. Using a combination of SRIM, molecular dynamics and kinetic Monte Carlo (kMC), we calculate the fraction of He atoms that end up in substitutional sites shortly after implantation, i.e. before they contribute to long-term microstructural evolution. We find that fractions of at most 3% should be expected for most implantation studies. Additionally, to inform the kMC calculations, we carry out an exhaustive calculation of interstitial He migration energy barriers in the vicinity of matrix vacancies and find that they vary from approximately 20-60 meV depending on the separation and orientation of the He-vacancy pair.     

Depth resolution and recoil cross section for analyzing hydrogen in solids using elastic recoil detection with 4He beam

Two aspects of the elastic recoil detection technique for analyzing H and D are described; i) experimental factors which effectively limit the depth resolution in Al film, and ii) determination of the recoil cross section for H(⁴He, ⁴He)H and D(⁴He, ⁴He)D reactions in the range of 1.5–3.0 MeV energy of ⁴He. Both experimental and theoretical estimates of the depth resolution are presented and are in good agreement each other. The theoretical estimate therefore provides a reliable guide to find optimum resolution conditions. The recoil cross section for H is more than double the theoretical Rutherford scattering value and that for D becomes greater than 30 times Rutherford near the resonance energy of 2.1 MeV ⁴He.