中文摘要：

通过采用线性折射率bar模型处理多维梯度折射率介质，本文研究了二维矩形半透明体的表观方向发射特性．考察了折射率分布、散射反照率、散射相函数等多种参数对二维梯度折射率介质表观发射的影响．提出类相干性的概念描述多维梯度折射率介质的辐射特性。

英文摘要：

Using the linear refractive index bar model, the apparent emissivity of a two dimensional scattering graded index semitransparent medium was studied in this paper. The influence of the refractive index distribution, scattering albedo and phase function are considered. The emission discussed in this paper was named as quasi coherent emission.