利用硅光电池测量硅单晶半导体材料的禁带宽度

以白炽灯为光源照射单晶硅光电池,测量在硅光电池前加不同截止波长的滤色片时的短路电流.通过短路电流和截止波长的关系,经拟合得到单晶硅材料的长波限,再利用半导体材料的长波限与半导体的禁带宽度Eg的关系,即Eg=hc/λ,计算得出其禁带宽度.     

一氧化氮血红蛋白等几种血红蛋白的拉曼光谱研究

一氧化氮血红蛋白、高铁血红蛋白、氧合血红蛋白、去氧血红蛋白的拉曼光谱被比较研究。实验显示用632.8 nm激发的拉曼光谱可检测氧合血红蛋白(低自旋)由R态到去氧血红蛋白(高自旋)T态的转变;同时一氧化氮血红蛋白与高铁血红蛋白的自旋态差异也可在拉曼光谱中清楚显现。632.8 nm激发的拉曼光谱可提供直接便利的方法鉴别一氧化氮血红蛋白及高铁血红蛋白这对相互关联的血红蛋白分子。     

平行光斜入射光栅(矩孔)的衍射光场

在"衍射光栅光栅常量的测定"实验中用矩孔代替光栅,利用菲涅尔-基尔霍夫积分公式,计算出平行光以任意倾斜角度入射后的光场分布公式,当平行光斜入射且接收屏与矩孔平面平行时,光斑分布图形为双曲线,并结合实验图像和计算机模拟,很好地验证了公式的正确性,解释了实验中观察到的现象.     

Surface Tension and Electrostriction in a Suspended Bridge of Dielectric Liquid

The mechanism of the formation of a surprisingly long suspended liquid bridge subjected to a dc electric field has been intensively studied in the past few decades. However, the role of electrostriction and quantitative evaluation of surface tension in the bridge have not been evaluated. We present combined theoretical and experimental studies on this issue. Electrostriction is pointed out to be the driving force that pushes liquid upward against gravity and into the gap between two containers and forms the suspended bridge, which is within the framework of the Maxwell pressure tensor. Through a comparison between experiment and theory, the surface tension is found to play an important role in holding the long suspended bridge. Ignorance of the surface tension leads to much smaller bridge length than the experimental values. The dynamic stability of the bridge with respect to its diameter, length and conductance is also discussed.