A facile citric acid assisted sol-gel combustion method was performed to synthesize cobalt chromite (CoCr₂O₄) ceramic pigment. The effect of the annealing temperature on structure, morphologies, and optical properties of the prepared Co₂O₄ pigments were systematically studied by thermogravimetry, differential thermal analysis, X-ray diffraction (XRD) and field emission scanning electron microscope (FESEM). The results show that Co₂O₄ spinel crystal was achieved after heat treatment of the as-burnt powder at a relatively low temperature (400 °C) and the average crystallite size of the Co₂O₄ pigment increased with the annealing temperature. Furthermore, on the CIE parameters of Co₂O₄ pigment, a* and b* values became much more negative with the annealing temperature due to much more Co²⁺ ions located in tetrahedral sites and much more Cr³⁺. ions located in octahedral sites. Finally, the measured solar absorptance indicates that this ceramic pigment is expected to fabricate the color paint coating for solar absorber application.

三维特征荧光参数可以反映污水处理过程中污染物的种类、性质和含量变化等丰富信息.通过对水样进行三维荧光特性分析和常规有机污染物指标COD,TN,TP的对比分析,确定表征污水中溶解性有机污染物种类、组成和含量的三维特征荧光.对进水、间隙水和出水中DOM的四种不同组分的荧光光谱图、荧光峰值(R.U.)、荧光指数FI、腐殖化指数HIX以及与COD,TN,TP的相关性进行研究可知:污水处理前后特征荧光峰中心位置和强度均发生明显的改变,表明污水中有机物的相对组成和含量随处理过程而变化;类腐殖质组分的降解情况不显著,而类蛋白组分的降解情况显著,类蛋白组分与COD,TN,TP呈现显著正相关.采用三维荧光光谱法分析了污水处理过程中溶解性有机物的荧光特性变化规律,探讨三维荧光技术用于描述污水处理过程中溶解性有机污染物降解规律的可行性。

Based on the optical Tamm states (OTSs), a metal-distributed Bragg reflector (DBR) structure is presented. The existence of optical Tamm states is demonstrated by the dip of reflectivity spectrum in photonic band gap. The properties of the optical Tamm states are investigated by applying the transfer matrix method. The effects of different metal thicknesses and angles on the absorption are studied by numerical simulation. The wide-angle perfect absorption appears when the metal thickness is 39 nm.