中文摘要：

根据空间分辨漫反射的双点源混合漫射近似模型，推导了空间分辨漫反射率对生物组织吸收系数ua和有效散射系数以灵敏度的解析表示，系统研究了在强吸收条件近光源区域吸收系数肛。和有效散射系数越对漫反射光子分布的影响．研究表明：吸收系数的灵敏度随光源与探测器间距P的增加呈线性增长，其斜率正比于（以／ua）1/4比例系数约为1．4，同时获得一个优化的探测距离popt距离光源约3．4个输运平均自由程，在这个距离处有效散射系数的变化对测量吸收的影响最小．这项研究对于生物组织的光学性质测量以及漫反射光谱技术的应用具有重要意义．

英文摘要：

Based on a theoretical model for spatial diffusion reflection with two-point-source hybrid diffusion approximate to a semi-infinite homogeneous turbid medium, expressions of the sensitivities for the absorption coefficient/z and the reduced scattering coefficient #1 are derived, and the effect of the sensitivities of the two optical parameters/z and #18 on diffuse reflectance is studied systematically in small volumes of highly absorbing medium. The results show that the sensitivity of the absorption coefficient increases approximately t 1/4 linearly with the increase of source-detector separation p, with a slope proportional to 1.4 （is/ua,）1/4 , and also indicate an optimal probe spacing popt at which a variable reduced scattering coefficient has a smallest effect on the measurment of optical absorption in the turbid medium. The value of popt is approximately equal to 3.4 times transport mean free path. The study is of great significance for the measurment of the optical properties of biological tissues and the application of diffuse reflecance spectroscopy technology.