太阳能-空气光伏/光热一体化热泵热水系统实验特性

本文研究了一种新型光伏/光热一体化(PV/T)复合热源热泵热水系统,将多孔扁盒式PV/T集热板与空气源热泵相结合,根据不同控制方式组合成双热源并联、单太阳能和单空气能三种不同运行模式。在室外环境温度28.5℃下,将200 L 30℃热水加热到55℃,研究了加热时间、热水温度、COP等性能的变化规律,结果表明双热源并联运行模式下分别比单太阳能模式和单空气能模式的加热时间缩短了42%和54%,COP分别提高了32.78%和47.64%;同时实验研究了在夏季工况下将200 L水从9∶00循环加热到17∶00过程中系统热性能,探讨了太阳辐射强度、PV/T集热板温度对光电/光热效率的影响,通过实验对比可以得出在热电模式下系统的光电效率η_(pv)比单一光电模式平均高25.8%.     

Control Charts for the Lognormal Mean

Among a set of tools that form the core of statistical process control, statistical control charts are most commonly used for controlling, monitoring, and improving processes. The conventional control charts are based on the assumption that the distribution of the quality characteristic to be monitored follows the normal distribution. However, in real applications, many process distributions may follow a positively skewed distribution such as the lognormal distribution. In this study, we discuss the construction of several control charts for monitoring the mean of the lognormal distribution. A real example is used to demonstrate how these charts can be applied in practice. Copyright © 2015 John Wiley & Sons, Ltd.     

Excited State Modulation for Organic Afterglow: Materials and Applications

Organic afterglow materials, developed recently by breaking through the difficulties in modulating ultrafast‐decayed excited states, exhibit ultralong‐lived emission for persistent luminescence with lifetimes of several orders of magnitude longer than traditional fluorescent and phosphorescent emissions at room temperature. Their exceptional properties, namely ultralong luminescent lifetime, large Stokes shifts, facile excited state transformation, and environmentally sensitive emission, have led to a diverse range of advanced optoelectronic applications. Here, the organic afterglow is reviewed from the perspective of fundamental concepts on both phenomenon and mechanism, examining the technical challenges in relation to excited state tuning and lifetime elongation. In particular, the advances in material design strategies that afford a large variety of organic afterglow materials for a broad utility in optoelectronics including lighting and displays, anti‐counterfeiting, optical recording, chemical sensors and bio‐imaging are highlighted.