MAX相Ti3SiC2管材在高温高压水和过热蒸汽中的腐蚀行为

MAX相材料有作为事故容错燃料(accident tolerant fuel,ATF)包壳材料的潜力,为了全面了解MAX相材料在模拟正常工况下的腐蚀行为,使用基体为Ti₃SiC₂的MAX相陶瓷管材于400℃/10.3 MPa过热蒸气,360℃/18.6 MPa去离子水、3.5μL/L Li+1000μL/L B溶液和70μL/L Li溶液4种不同的水化学条件中进行腐蚀试验,采用XRD、SEM和FIB/TEM观察分析腐蚀前后样品的显微组织、晶体结构和成分。结果表明,Ti₃SiC₂管材在4种条件下的腐蚀速率均远高于参比Zr-4合金,腐蚀后主要检测到腐蚀产物TiO₂,且其表面疏松多孔,未形成保护性的氧化膜。     

Development of deformation model for simulation of mechanical behaviors of coated-cladding

A coated fuel cladding is one of the promising accident tolerant fuel (ATF) cladding concepts to enhance the fuel safety for accident conditions. In this study, a new analytical model called Fuel Rod and Cladding Analysis Subcode-Coated Cladding (FRACAS-CT), used to evaluate the mechanical behaviors of the ATF cladding, has been developed employing both thick-walled theory and some methodologies of the FRACAS. Based on the methodology of FRACAS, two different regimes of pellet-cladding mechanical interactions according to the gap status were considered as follows: one is an open-gap regime, and the other is a closed-gap regime. FRACAS-CT was developed within a limited scope of an elastic solution under the assumption of the prescribed creep, irradiation growth, and thermal deformation. To verify the FRACAS-CT model, an equivalent finite element (FE) model was proposed, and the mechanical behaviors of FRACAS-CT were compared with those of the equivalent FE model. As a result, it was determined that the stress results of FRACAS-CT are highly consistent with those of the equivalent FE model. Furthermore, FRACAS-CT was implemented into the FRAPCON4.0P1 code system to evaluate the mechanical behaviors of the ATF cladding using in-reactor conditions.     

自动传动液抗颤性能要求及评价方法

随着汽车市场的发展和逐渐成熟,自动挡轿车将更加受到消费者的青睐。目前在自动变速器中普遍采用的限滑锁止离合器系统能够有助于提高整车的燃油经济性及NVH性能（Noise,V ibration,Harshness,即噪音,振动与舒适性）,因此要求自动传动液具备良好的抗颤抖性能,否则将影响驾驶舒适性。研究表明可以通过测量摩擦系数μ与滑动转速v之间的关系,来判断自动变速器系统出现颤抖的趋势,即通过判断μ-v曲线是正斜率还是负斜率的方法。文章介绍了自动传动液的抗颤抖性能要求及评价车用自动传动液抗颤抖性能实验方法,即JASO M349。     

基于LabVIEW和Atmega16的GAL16V8编程器的制作

介绍一种由PC机USB串口发送数据到Atmega16单片机并由Atmega16控制编程的GAL16V8编程器的制作。详述了GAL16V8烧录器的硬件电路的设计,单片机Atmega16如何根据指令进行烧录,以及用软件LabVIEW实现编程数据顺序的调整。该编程器实现了对LATTICE公司的GAL16V8B、GAL16V8D与ATMEL公司的ATF16V8B的不同烧录指令,适用于实验教学。     

Genetic analysis of geraniol metabolism during fermentation

Geraniol produced by grape is the main precursor of terpenols which play a key role in the floral aroma of white wines. We investigated the fate of geraniol during wine fermentation by Saccharomyces cerevisiae. The volatile compounds produced during fermentation of a medium enriched with geraniol were extracted by Stir-bar sorptive extraction and analysed by GC–MS. We were able to detect and quantify geranyl acetate but also citronellyl- and neryl-acetate. The presence of these compounds partly explains the disparition of geraniol. The amounts of terpenyl esters are strain dependant. We demonstrated both by gene overexpression and gene-deletion the involvement of ATF1 enzyme but not ATF2 in the acetylation of terpenols. The affinity of ATF1 enzyme for several terpenols and for isoamyl alcohol was compared. We also demonstrated that OYE2 is the enzyme involved in geraniol to citronellol reduction. Fermenting strain deleted from OYE2 gene produces far less citronellol than wild type strain. Moreover lab strain over-expressing OYE2 allows 87% geraniol to citronellol reduction in bioconversion experiment compared to about 50% conversion with control strain.     

基于AVR单片机三相功率因数测算的研究

提出一种利用AVR单片机与ATF16V8相互配合测算三相功率因数的新方法。经试验该方法具有较高的测量精度,并能很好地抑制干扰信号,此方法还可用于多路相位采集系统。首先简要介绍了一路相位差的求解方法,又详细阐述三路相位差的求解方法以及对应的抗干扰措施,最后对整个测算系统的性能进行分析,测得相位角分辨率可达0．09°。     

Evaluation of microbially influenced corrosion with electrochemical noise analysis and signal processing

Corrosion behaviors of stainless steel (SS304), with attached Acidithiobacilus ferrooxidans (ATF) bacteria and exposed to three different types of artificial saliva solutions, namely: (1) Jenkin's solution, (2) Tomasi's solution, and (3) NaCl solution, have been monitored using electrochemical noise (ECN) analysis and signal processing techniques. The ECN data has been analyzed in time and frequency domains, and the time-domain analysis was used to calculate parameters such as skewness, kurtosis and noise resistance, R_n. The corrosion mechanisms were analyzed in terms of the ranges of skewness and kurtosis. The frequency analysis showed that the conventional fast Fourier transforms (FFT) method failed to differentiate among the ECN signals obtained in different solutions with and without the attachment of bacteria. Therefore, the fractional Fourier transform (FrFT) was introduced to process ECN signals and has been demonstrated as a better tool to describe the corrosion behaviors of electrodes in different solutions.     

复杂环境下基于时延估计的声源定位技术研究简

为了改善在复杂环境下声源定位算法的性能,提出了一种新的时延估计（TDE）方法,即基于传递函数比的统计模型方法（ATFR-SM）。该方法采用统计模型去除噪声对传递函数（ATF）的影响,在计算传递函数时对功率谱密度（PSD）进行平滑和“白化”,以去除混响对传递函数的影响。同时,算法中引入话音激活检测（VAD）去除对求取传递函数无用的噪声段,以提高时延估计的准确性。此外,将所提时延估计方法与线性定位法相结合,构成一套完整的声源定位方法。实验结果表明,在复杂环境下,时延估计方法具有更低的异常点百分比（PAP）和均方根误差（RMSE）,且明显优于传统的参考算法,同时声源定位方法具有更高的定位精度。     

锆合金耐事故燃料包壳涂层研究进展

日本福岛核事故后,以提升反应堆在事故工况下的稳定性和安全性为目的的事故容错燃料技术研究已成为世界范围内的研究热点。涂层技术是事故容错燃料项目短期规划主要的发展方向。在锆合金燃料包壳表面制备保护性涂层能够在不改变现有燃料体系结构的前提下,提升锆合金包壳在反应堆失水事故条件下的事故容错能力。本文综述了国内外锆合金包壳涂层领域研究成果,总结了锆合金表面涂层的种类、性能、制备技术及应用前景,结合涂层的制备技术,综合分析了各种制备方法的特点以及未来需集中要解决的问题。在此基础上,提出金属Cr涂层具有良好的耐腐蚀性能,尤其是在>1200°C高温蒸汽腐蚀条件下能够有效保护锆合金基体,是目前最有希望工程化应用的事故容错涂层。同时,探索适合于工程化应用的Cr涂层制备技术,解决Cr涂层的制备缺陷,提升涂层的结构致密性以及界面性能是目前亟待解决的关键问题。     

汽车自动变速器油质异常的原因及预防措施

介绍了汽车自动变速器油质检查的正确方法，详细地分析了汽车自动变速器油质异常的原因以及预防汽车自动变速器油早期变质的一些具体措施。