1 中国科学院 青海盐湖研究所 中国科学院盐湖资源综合高效利用重点实验室, 西宁 810008
2 青海省盐湖资源化学重点实验室, 西宁 810008
3 中国科学院大学, 北京 100049
4 大连理工大学 化工学院, 大连 116024
采用水热法以氯化镁和氢氧化钙为原料制备了碱式氯化镁(BMC)晶须, 然后热解得到了纳米氧化镁。经透射电镜(TEM)和选区电子衍射(SAED)分析其粒径在20~40 nm之间, 暴露晶面族为{111}和{110}。通过热重差热分析(TG-DTA)、扫描电镜(SEM)、X射线衍射(XRD)以及红外光谱(FT-IR)分析确定了碱式氯化镁晶须热分解过程分四步进行, 前两步分别脱去两个结晶水, 第三步脱氯化氢, 最后脱羟基水。采用Satava法和微分法对BMC晶须的热分解机理和动力学进行了研究, 得出第一步反应热分解机理为随机成核与随后生长、第二步为二维扩散、第三步为相边界反应、第四步为一维相边界反应。
碱式氯化镁 纳米氧化镁 热分解 晶须 水热法 basic magnesium chloride nano magnesium oxide thermal decomposition whiskers hydrothermal method
Author Affiliations
Abstract
1 Wuhan National Laboratory for Optoelectronics, Huazhong Institute of Electro-Optics, Wuhan 430223, China
2 School of Optical and Electronic Information, Huazhong University of Science and Technology, Wuhan 430074, China
Due to the limit of the pixel size of the charge-coupled device (CCD) or complementary metal oxide semiconductor (CMOS) sensor, the traditional differential algorithm has a limited measuring accuracy by determining the critical an-gle in integral pixel. In this paper, we present a practical algorithm based on the centroid value of the reflective ratio around the critical angle pixel to address the traditional differential algorithm problem of determining the critical angle under sub-pixel in a critical angle refractometer (CAR). When the change of refractive index (RI) of a liquid sample is beyond the sensitivity of the traditional differential algorithm, the RI of the liquid can be obtained by using the cen-troid value of reflectivity around the critical angle pixel. The centroid value is associated with the RI change of the liq-uid in sub-pixel. Demonstrated by both theoretical analyses and experimental results using saline solutions with RI that changes in sub-pixel tested through the reflective CAR, the algorithm is found to be computationally effective and ro-bust to expand the measuring accuracy of the Abbe-type refractometer in sub-pixel.
光电子快报（英文版）
2019, 15(2): 108
