99超碰中文字幕在线观看-天天干天天日天天舔婷婷-我看操逼的好看的女人的-日本一二三四五区日韩精品

 文獻(xiàn)名：Novel Bi3+ doped and Bi3+/Tb3+ co-doped LaYO3 pigments with high near-infrared reflectances 

 

作者：Yu Xiao^a,b, Bin Huang^a, Jinqing Chen^b, Xiaoqi Sun^a 

^a CAS Key Laboratory of Design and Assembly of Functional Nanostructures, and Fujian Key Laboratory of Nanomaterials, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian 350002, PR China

^b School of Metallurgy and Chemical Engineering, Jiangxi University of Science & Technology, Ganzhou, 341000, China

 

摘要：A series of environmentally benign and high NIR reflective pigments based on Bi3+ doped and Bi3+/Tb3+ co-doped LaYO3 are synthesized via the sol-gel method. The resulting powders were characterized by X-ray diffraction, UV–vis–NIR spectrophotometer and CIE L*a*b* (1976) color space. The doping of Bi3+ for La3+ in LaYO3 results in the color changes from light yellow to dark yellow and Bi3+/Tb3+ for La3+ in LaYO3 varies from soft orange to dark orange. Meanwhile, the band gaps of pigments decrease from 4.52 eV to 2.95 (Bi-doped) and 2.15 eV (Bi/Tb co-doped). Interestingly, the Bi-doped pigments possess high NIR solar reflectance (>95%) in the range of 700–2500?nm. In contrast, the Bi/Tb co-doped pigments decrease the NIR solar reflectance from 98.28% to 78.77%. The applicability studies of La0.5Bi0.5YO3 and La0.5Bi0.25Tb0.25YO3 pigments with TiO2 base coat on galvanized sheet reveal good coloring performance with high NIR reflectance. Acid/alkaline tests indicates good chemical stabilities of the pigments under the extreme weather conditions. The superior performances of developed pigments have revealed potentials to be employed in cool coatings.