350℃下长期时效对17-4PH不锈钢动态断裂韧性的影响

利用示波冲击试验系统研究反应堆用17-4PH马氏体不锈钢在使用温度（350℃）下长期(约11000h)时效过程冲击性能和动态断裂韧度的变化规律，并用扫描电镜观察分析不同时效时间的CharpyⅤ型缺口试样（CVN）的断口形貌。结果表明：该马氏体不锈钢在350℃长期时效的过程中，随着时效时间的延长,其塑性变形能E_PL和撕裂能E_TE以及冲击功E_t均随时效时间的延长而逐渐下降。根据示波冲击曲线获得了该钢的动态断裂韧度K_Id，其动态断裂韧度也随时效时间的延长而逐渐下降，并在试验的初始阶段下降很快，在试验的中后期下降较为缓慢。另外，该不锈钢的CVN冲击试样断口形貌随着时效时间的延长由韧性断裂机制的韧窝断裂为主向脆性断裂机制的准解理断裂和穿晶断裂为主变化。这些均说明，随着时效时间的延长，该材料的韧性降低，发生了脆化，且脆化主要发生在试验的初始阶段。     

人工神经网络在棒束临界热流密度预测中的应用

基于已有的棒束临界热流密度数据库，采用COBRA-Ⅳ程序计算得到子通道局部临界热流密度数据库。用人工神经网络（ANN）理论对数据库进行训练，得到基于ANN理论的棒束临界热流密度预测模型。预测模型的预测精度显著高于常用经验关系式的预测精度，其预测值的均方差为5.63%。     

复杂几何燃料组件的参数计算

利用加拿大蒙特利尔大学研制的DRAGON程序对反应堆复杂几何组件进行参数计算，并通过压水堆柱状元件基准问题、MTR型反应堆板状元件基准问题和其他不同几何形状的燃料组件进行校核计算。结果表明：DRAGON程序可用于多种复杂几何燃料组件参数的计算，且具有良好的计算精度。      

基于时序CPN的交叉路口车辆控制模型

对比经典Petri网模型，提出了基于时序CPN的交叉路口车辆控制模型，从时间和空间上对车辆的流通进行描述。使用CPN Tools建立时序CPN模型并进行仿真，模拟了交叉路口的车辆交通过程，实验结果证明该模型很好的反映了车辆流通时的时间和位置信息等动态特征。     

一种基于多相带通结构的信道化滤波器算法

针对信道化滤波器要求运算速度快、消耗资源多、难以实时处理的突出问题，从多相滤波器，信道化滤波器的结构、原理和运算效率分析出发，推导了一种基于多相带通结构的信道化滤波器算法模型。这种算法将现有多相结构信道化滤波器模型中的低通设计改为带通设计，实现了复数乘法运算全部集中在带通滤波环节当中，并采用协调分级DFT算法的实现方案，大幅度节省了硬件资源，提高了运算效率，实现了信道化滤波器在通用FP—GA和DSP芯片中的实时处理，硬件仿真结果验证了算法模型的正确性和有效性。     

The recovery and recrystallization of cold rolled V-W-Ti alloys

Several V-W-Ti alloys with about 50% reduction in thickness by cold rolling were isochronally annealed at temperatures from 100 to 1100 °C. Hardness was measured after the annealing. By comparison with V4Cr4Ti and V4Ti alloys, the V6WTi alloy was found to begin recovery at a temperature about 100 °C higher, while the full recrystallization temperature was around 900 °C for all of the alloys. Hardness decreased successively above 500 °C in V8W, as is the case in pure V. Impurity induced hardening was observed around 300 °C only in the alloys without Ti. Precipitation and the interaction between interstitial impurities and dislocations were supposed to be the main contributors to the different recovery and recrystallization behaviors of the alloys.     

HL-2A Tokamak Edge Modeling with B2

The outer divertor plasma of HL-2A and its associated scrape-off plasma have been simulated using a two-dimensional multi-species fluid code of Braams with a simplified neutral gas model. HL-2A has a double-null closed divertor in separate divertor chambers above and below the nearly circular plasma tours. The computed numerical grid is developed according to an ideal magnetic surface. The calculation is involved only with pure hydrogen plasma. The emphasis has been focused on parametric studies involving variation of the assumptions made for the core plasma. The peak temperatures and the heat flux near the target are of the principal concern。     

微波场下纳米Mg-Al-LDHs及PO43-,P2O74-柱撑Mg-Al层状双氢氧化物的合成

用微波加热反应-变速滴加共沉淀法合成了[Mg-Al-CO3]纳米层状双氢氧化物，并以[Mg-Al-CO3]纳米层状双氢氧化物为前体，用微波加热反应一离子交换法制备了PO4^3-，P2O7^4-柱撑Mg-Al层状双氢氧化物．该法合成的[Mg-Al-CO3]纳米层状双氢氧化物的粒径约为10～40nm．讨论了微波和变速滴加碱液的速度对纳米层状双氢氧化物的合成的影响．用FT-IR、TEM与XRD对产物进行了表征，结果表明在微波加热反应的条件下可在短时间内用PO4^3-,P2O7^4-彻底交换CO3^2-。     

TEM study on precipitation and transformation of secondary carbides in 16Cr–1Mo–1Cu white iron subjected to subcritical treatment

High chromium white irons solidify with a substantially austenitic matrix supersaturated with chromium and carbon. The subcritical heat treatment can destabilize the austenite by precipitating chromium-rich secondary carbides and other special carbides. In the as-cast condition the eutectic carbides are (Fe,Cr)₇C₃ and (Fe_4.3Cr_2.5Mo_0.1)C₃. The initial secondary carbide precipitated is (Fe,Cr)₂₃C₆ after heat-treating at 853 K for 10 h. There are MoC, Fe₂MoC and -carbide precipitating, and (Fe,Cr)₂₃C₆ transforms to M₃C after 16 h at 853 K. The -carbide and (Fe,Cr)₂₃C₆ accomplish transformation to M₃C and the matrix changes from martensitic to pearlitic after 22 h at 853 K. Thereby, in the subcritical heat treatment process, the initial secondary carbide precipitated is (Fe,Cr)₂₃C₆, followed by -carbide, MoC and Fe₂MoC. In addition, there are two in situ transformations from (Fe,Cr)₂₃C₆ and -carbide to M₃C carbides.     

Experimental research progress on critical heat flux of Chinese PWR

One of the most important requirements in the design of pressurized water reactor (PWR) is to avoid the occurrence of critical heat flux (CHF). The design criteria for PWR specify that they must be operated at a certain percentage below CHF at all times and locations so as to the cladding temperature of fuel element at safe values. So in the process of safety assessment, CHF is one of important thermal-hydraulic parameters limiting the available power, whose size directly affects safety and economy of PWR nuclear power plant. This paper deals with a summary of experimental research progress on CHF of Chinese PWR. It mainly presents CHF experimental researches of Φ10 fuel assembly, CHF experimental researches of standard fuel assembly, and CHF experimental progress of non-uniform heated rod bundles. It should be emphasized that it also presents experimental research programs on CHF of Chinese advanced fuel assembly with self-reliance copyright. All CHF data obtained will be used for design improvement of Chinese PWR and R&D program of New Generation 1000 MWe PWR.