超超临界锅炉燃烧配风优化的三维数值模拟

建立了带二次风道的660 MW超超临界墙式切圆锅炉的三维数理模型,采用Realizable k-ε双方程湍流模型模拟气相湍流流动,采用P-1辐射模型来描述炉内辐射换热,采用混合分数/概率密度函数模型模拟气相湍流燃烧.研究了锅炉二次风风门挡板的阻力特性,并探究了附加燃尽风门挡板开度对660 MW墙式切圆锅炉燃烧与污染物排放特性的影响.结果表明:附加燃尽风风量与其风门开度阻力系数有关,当风门开度小于50%时,附加燃尽风风门阻力系数曲线斜率大幅增加,风量随开度变化的幅度增大;随着附加燃尽风门挡板开度增加,NOx浓度降低,但在炉膛上部煤粉发生二次燃烧,引起屏底烟气温度升高.     

Real-time measurement of retardation of eighth-wave plate independent of fast-axis direction

A real-time measurement method for the retardation of an eighth-wave plate is proposed. The collimated laser beam is split using a Glan Taylor polarizer with two side escape windows. The reflected sub-beam is detected using a detector, whereas the transmitted sub-beam passes through the quarter-wave plate and the eighth-wave plate of interest. Then, it is reflected by the mirror and passes reversely through the eighth-and quarter-wave plates. Finally, it is analyzed using the Glan Taylor polarizer and detected using another detector. With two detection signals, the retardation is resolved and found to be independent of the fast-axis direction, initial intensity, and circuit parameters. In the experiment, a crystal quartz sample is measured at different fast-axis angles. The standard deviation of the retardation is 0.9 o . The usefulness of the method is verified.     

东江流域河水电导率形成机制

 分别于枯水期和丰水期在东江流域包括干流和支流在内的100个站点实测河水的电导率及相关离子浓度,据此讨论了河水电导率的形成机制。结果表明,东江流域枯水期（1月份）河水电导率均值为853 μS/cm,丰水期（7月份）河水电导率均值为877 μS/cm。东江流域河水电导率（离子浓度）主要来自地表岩石和矿物的化学风化过程,人类活动对东江河水电导率的干扰较为明显,同时大气海盐沉降过程对东江河水电导率也产生一定程度的影响。运用非参数统计和空间分析等手段处理原始数据,定量地发现流域岩性、地貌、土壤、植被和人类活动等因素对河水电导率均具有大小不同的贡献。     

ATR-THz波谱结合PLS-DA对陈化小麦快速无损鉴别研究

采用ATR附件采集了人工控制条件老化小麦样品的太赫兹波谱数据,并在PCA综合得分基础上对数据进行分集,建立陈化小麦的快速无损鉴别PLS-DA模型,并对其进行外部验证。结果显示,针对吸收系数谱,所建模型的校正集实验组、对照组以及交互验证实验组、对照组正确率分别为84.2%,94.7%,84.2%和81.6%,外部验证集实验组、对照组正确率分别为73.7%和100.0%;针对折射率谱,所建模型的校正集实验组、对照组以及交互验证实验组、对照组正确率分别为84.2%,92%,76.3%和76.3%,外部验证集实验组、对照组正确率分别为84.2%和89.5%。研究表明,ATR-THz技术在陈化小麦无损鉴别方面具有一定的应用潜力。