JXTA技术中RPV的改进策略

JXTA技术的对等网络中普遍存在RPV管理不足的现象,该现象对网络中的信息传递有较大影响.分析了现有RPV中的聚集对等点信息管理的缺陷,以及由此导致的查询效率和网络性能的降低.提出了对RPV的改进策略,并给出了相应的查询消息发送机制.改进后的RPV策略提高了查询效率,并改善了RPV的适应性.     

JRQ and JPA irradiated and annealed reactor pressure vessel steels studied by positron annihilation

The paper is focused on a comprehensive study of JRQ and JPA reactor pressure vessel steels from the positron annihilation lifetime spectroscopy (PALS) point of view. Based on our more than 20 years’ experience with characterization of irradiated reactor steels, we confirmed that defects after irradiation start to grow and/or merge into bigger clusters. Experimental results shown that JPA steel is more sensitive to the creation of irradiation-induced defects than JRQ steel. It is most probably due to high copper content (0.29?wt.% in JPA) and copper precipitation has a major impact on neutron-induced defect creation at the beginning of the irradiation. Based on current PALS results, no large vacancy clusters were formed during irradiation, which could cause dangerous embrittlement concerning operation safety of nuclear power plant. The combined PALS, small angle neutron scattering and atomic probe tomography studies support the model for JRQ and JPA steels describing the structure of irradiation-induced clusters as agglomerations of vacancy clusters (consisting of 2–6 vacancies each) and are separated from each other by a distribution of atoms.     

CP violation in B→φKs decay in R-parity violating supersymmetry

In the framework of R-parity violating supersymmetry, we investigate the time dependent CP asymmetry SφKs anomaly of B→φKs decay. When the values of the weak phase φ in the R-parity violating coupling fall into certain parameter spaces (246°<φ<263°) we find that this anomaly can be easily ex-plained; at the same time, the branching ratio of B →φKs decay can also be in agreement with experimental measurements.     

CP violation in B→φKs decay in R-parity violating supersymmetry

In the framework of R-parity violating supersymmetry, we investigate the time dependent CP asymmetry SφKs anomaly of B→φKs decay. When the values of the weak phase φ in the R-parity violating coupling fall into certain parameter spaces （246°〈 φ 〈 263°） we find that this anomaly can be easily explained; at the same time, the branching ratio of B→φKs decay can also be in agreement with experimental measurements.     

核反应堆压力容器模拟钢中纳米富Cu相的变形特征

提高了Cu含量的核反应堆压力容器(reactor pressure vessel,RPV)模拟钢样品,经过880 cC水淬、660℃调质处理和400℃1000～4000 h的等温时效处理,观察到纳米富Cu相的析出;随后进行20%～30%冷轧变形,采用萃取复型(extractionreplica,ER)和高分辨透射电镜(high resolution transmission electron microscopy,HRTEM)的方法研究纳米富Cu相的变形特征.研究结果表明,镶嵌在α-Fe基体中的纳米富Cu相,在冷轧变形时的变形机制较为复杂,存在多种变形方式.当纳米富Cu相的晶体处于有利取向时,可以跟随基体一起发生滑移变形,表现为"软"颗粒的特性;当晶体处于不利取向时,会发生孪生变形,甚至诱发马氏体相变,有时生成"轮毂辐条"状的孪晶结构,大大提高了纳米富Cu相继续变形时的抗力,表现为"硬"颗粒的特征,因而析出纳米富Cu相会产生明显的强化作用.     

混凝土抗压强度回弹测试数据的分形分析

分形理论在处理无规离散数据方面具有独特优点,应用于混凝土抗压强度回弹测试数据这一无规离散数据的处理时,能够得到比常规回归法更加可靠的抗压强度数据.文中通过在二维平面坐标上建立回弹测点位置-回弹值曲线(RPV曲线),采用盒维数计算法编制计算程序,得出RPV曲线的分形维数,并用来推算混凝土抗压强度.结果表明,RPV曲线分形维数与混凝土抗压强度间具有线性关系,且该法推算混凝土抗压强度可在不测试碳化深度的情况下进行,适应于大体积混凝土抗压强度的检测,为简化混凝土抗压强度的检测提供了新途径.     

Vacancy-solute complexes and their clusters in iron

In this contribution, several vacancy-solute complexes in iron are investigated theoretically from the viewpoint of positron annihilation. In particular, V-Si, V-P, V-Cr, V-Mn, V-Ni, V-Cu and V-Mo complexes are examined. In addition, nano-sized vacancy-Cu clusters in the Fe matrix are also studied. We concentrate on positron lifetimes and coincidence Doppler broadening profiles that bring complementary information about the studied complexes and their clusters. Positron calculations are carried out using the atomic superposition method employing realistic atomic configurations obtained recently using an ab initio pseudopotential method (vacancy-solute complexes) and Monte Carlo/molecular dynamics methods (vacancy-Cu clusters). The main aim of this study is to predict as to what extent such defects are detectable and differentiable using positron annihilation techniques. The results obtained are discussed in the context of experimental data available in the literature.     

基于自主飞行的小型无人机动力自适应模糊控制

针对传统无人机动力系统控制的局限性，提出小型无人机动力自适应模糊控制策略。在飞行控制计算机内建立发动机工作点的自适应模糊控制器，同时控制发动机油门和风门，并将其融进二维查询表中，利用传感器获取当前的发动机工作状态信息，通过软件方法进行查表，经简单的因子换算即可获取精确的输出控制量，实现对发动机的闭环监控。     

反应堆压力容器安注过程瞬态传热特性研究

按1:10的比例建立了反应堆压力容器直接安注的试验模型,进行了流动可视化、常温常压下的传热与高温高压下的传热试验,并在试验研究的基础上,利用FLUENT5.4商用软件进行了数值模拟研究。通过研究获得了反应堆压力容器直接安注时的瞬态传热系数、流体的混合函数及瞬态温度的变化规律,为反应堆压力容器在安注时的承压热冲击分析提供了重要的依据。     

反应堆压力容器钢辐照硬化脆化的中子注量率效应

 针对中子注量率对核电站反应堆压力容器(RPV)钢辐照硬化脆化的影响,总结了不同铜含量RPV 钢的辐照硬化脆化的中子注量率效应.结果表明,在低铜(Cu≤0.08%)和高铜(Cu>0.08%)RPV 钢中,中子注量率对辐照硬化脆化有不同的作用结果.在中子注量率≤1×10¹² n·cm^-2·s^-1(E>1 MeV)的条件下,中子注量率对低铜RPV 钢辐照硬化脆化无明显影响,在>1×10¹²n·cm^-2·s^-1(E>1 MeV)的条件下,尚无确定结论;高铜RPV 钢辐照至富铜团簇硬化平台后,注量率对硬化脆化无影响,而达到辐照硬化平台之前,注量率对辐照硬化脆化有不同影响.