核电站用SA738Gr.B钢板热处理工艺研究

为满足SA738Gr.B核电站用钢较高的性能要求,在实验室试验的基础上,研究了工业化生产热处理工艺参数对钢显微组织和力学性能的影响。结果表明,钢板淬火时冷却速度5℃/s时,能够避免先共析铁素体的析出;淬火温度较高时,钢板具有更细小和均匀的板条贝氏体;随着淬火加热的保温时间延长,晶粒组织粗化且铁素体含量减少;随着回火温度的升高,晶粒粗化,同时贝氏体含量减少,铁素体含量增多;在工业化生产中,较大淬火水量下钢板的拉伸性能更优;随着回火时间的延长,钢板强度下降而冲击韧性提高。以920℃×2.0 min/mm加热、较高水量的Q2工艺淬火,并采用650℃×1.5min/mm的工艺回火,可使钢板的强韧性达到最佳匹配。     

Infrared thermography inspection for monoblock divertor target in JT-60SA

Carbon fiber composite (CFC) monoblock divertor target is required for power handling in JT-60SA. Quality of the targets depends on a joining technology in manufacturing process. To inspect the quality of more than 900 target pieces, efficient non-destructive inspection is needed. An infrared thermography inspection (IR inspection), has been proposed by ITER and IRFM, where the quality between CFC and a cooling tube is examined by a use of transient thermal response at a rapid switch from hot to cold water flow. In JT-60SA divertor target, a screw tube will be employed to obtain high heat transfer efficiency with simple structure. Since the time response of the screw tube is much faster than that of smooth tube, it is required to confirm the feasibility of this IR inspection. Thus, the effect of joining defects on transient thermal response of the targets has been investigated experimentally by using the mock-up targets containing defects which are artificially made. It was found that the IR inspection can detect the defects. Moreover, screening criteria of IR inspection for acceptable monoblock target is discussed.     

Latent polyphenol oxidase from quince fruit pulp (Cydonia oblonga): purification,activation and some properties

Quince fruit polyphenol oxidase (PPO) was partially purified using a combination of phase partitioning in Triton X‐114 and PEG 8000/phosphate with a final ammonium sulfate fractionation between 30% and 75%, to avoid the deep browning of the enzyme due to the high amount of oxidizing substances present in the quince pulp. The clean and stable enzyme was partially purified in a latent form and could be optimally activated by the presence of 0.5 g dm^?3 sodium dodecyl sulfate (SDS) with an optimum pH of 5.0. In the absence of SDS, the enzyme showed maximum activity at acid pH. The apparent kinetic parameters of the latent enzyme were determined at pH 5.0, the V_m value being 15 times higher in the presence of SDS than in its absence, whereas the K_M was the same in both cases, with a value of 1.2 mmol L^?1. The effect of several inhibitors was studied, tropolone being the most active with a K_i value of 4.7 µmol L^?1. In addition, the effect of cyclodextrins was studied, and the complexation constant (K_c) between 4‐tert‐butylcatechol and cyclodextrins was calculated using an enzymatic method. The value obtained for K_c was 15 310 mol L^?1. Copyright © 2006 Society of Chemical Industry     

诱抗剂处理对"银帝"甜瓜采后粉霉病和黑斑病的抑制效果

采前1d苯丙塞重氮（BTH）或康壮素（Harpin）处理，采后水杨酸（SA）处理可明显降低甜瓜果实采后损伤接种粉红单端孢（Trichothecium roseum）和交链孢（Alternaria alternata）的病斑直径，并且随着诱抗剂浓度的升高其效果越好，其中以100mg／L BTH或60mg/L Harpin，0．4mg／LSA处理的效果最佳。     

基于多移动代理的协同智能DSAS的结构设计

为提高安全审计系统的智能化、自动化、准确性、分布式安全性和协同整体效能,在分析网络安全审计系统（SAS）和移动代理（MA）技术特点的基础上,利用MA技术、协同技术和审计技术的集成优势,结合分布式及MA与SAS的特点,设计并构建了基于多MA的协同新智能分布式安全审计系统（DSAS）结构模型,解决了设计过程中的关键技术,同时提出了DSAS的实现过程及模拟测试的构思。     

300MW锅炉汽包筒体水侧纵向裂纹形成机理

某电厂300 MW机组锅炉汽包中锅筒水侧出现多条纵向裂纹。通过对裂纹附近的金相组织、残余应力、硬度以及运行工况的研究,分析了裂纹形成的原因。研究结果表明:汽包裂纹附近材料珠光体中碳化物球化,球状的碳化物聚集在合金铁素体的晶界上部分连成链状组织;裂纹位于筒体瓦片压制过程中形成的较深的纵向沟痕附近,在这些部位附近出现较高的应力集中;由于水位线的波动和变负荷运行产生的交变热应力导致水位线附近部位萌生低周疲劳裂纹;母材裂纹形成的主要原因是筒体中局部的应力集中、较大的交变热应力、材料组织变化以及锅水应力腐蚀的综合作用。     

CINRAD/SA雷达俯仰角码跳闪导致天线异动的故障排除

济南新一代天气雷达自2011年1-6月份,天线俯仰定位自行漂移、俯仰角码跳闪、俯仰预限位和死区限位、天线/发射机功率比变坏等报警无规律发生,造成雷达不能正常运行。文章着重分析了本次故障反复出现,并由此造成停机22天次,故障累计达127h的原因;总结了对这次疑难故障的排查和检修过程;提出了应对措施和解决方法。为雷达技术保障人员提供了现场维修、维护方面的经验,以达到快速排除故障的目的。     

CINRAD/SA雷达发射机温度异常问题及其解决方法

针对常州新一代天气雷达在运行过程中出现的发射机温度过高问题,进行分析并提出应对措施和解决方法,保证雷达发射机温度控制在雷达设计的正常范围内,确保新一代天气雷达正常运行。     

基于混合遗传算法的混流混合车间协同调度问题

为解决一类具有多品种混流生产特征和作业车间与流水车间集成的混流混合车间协同调度问题,给出了以在制品成本最小为目标的混流混合车间调度问题模型;采用零件加工、部件装配、产品总装的三段协同编码方法,给出了一种集成模拟退火算法的混合遗传算法,并在模拟退火算法中引入变温度参数来平衡算法效率。最后,通过某冰箱混流装配企业典型实例验证了模型和算法的有效性。     

基于DIO模块和SA4828的三相交流信号源的实现

针对常用三相交流电产生电路的不足,设计了一种频率和幅度可调的三相交流信号源。该信号源采用MITEL公司生产的SA4828作为三相正弦脉宽调制(SPWM)信号发生器,连接研华公司生产的DIO模块USB4751,在计算机软件的控制下,生成所需要的SPWM波形,再经过二阶有源滤波网络,即可得到作为系统激励的三相交流信号。该三相交流信号源输出的频率和电压值精确可调,电路结构简单,信号精度与稳定性高,试验结果表明系统性能满足应用要求。