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Accurate reconstruction of the optical parameter distribution in participating medium based on the frequency-domain radiative transfer equation 下载免费PDF全文
Reconstructing the distribution of optical parameters in the participating medium based on the frequency-domain radiative transfer equation(FD-RTE) to probe the internal structure of the medium is investigated in the present work.The forward model of FD-RTE is solved via the finite volume method(FVM). The regularization term formatted by the generalized Gaussian Markov random field model is used in the objective function to overcome the ill-posed nature of the inverse problem. The multi-start conjugate gradient(MCG) method is employed to search the minimum of the objective function and increase the efficiency of convergence. A modified adjoint differentiation technique using the collimated radiative intensity is developed to calculate the gradient of the objective function with respect to the optical parameters. All simulation results show that the proposed reconstruction algorithm based on FD-RTE can obtain the accurate distributions of absorption and scattering coefficients. The reconstructed images of the scattering coefficient have less errors than those of the absorption coefficient, which indicates the former are more suitable to probing the inner structure. 相似文献
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利用吹扫捕集气相色谱-原子荧光光度法测定土壤中烷基汞含量。分别用酸法消解和碱法消解处理土壤样品,对比了两种样品处理方法的效果,结果表明碱法消解优于酸法消解,该法具有步骤少,耗时短,使用的试剂种类少、毒性小,土壤中烷基汞回收率高等优点。甲基汞、乙基汞的质量在0.5~1 000 pg范围内与色谱峰面积线性关系良好,相关系数分别为0.999 9和0.999 8,当称样质量为0.5 g时,甲基汞的检出限为0.35μg/kg,乙基汞的检出限为0.53μg/kg。土壤样品加标回收率为70.0%~114.0%,测定结果的相对标准偏差为3.5%~12.0%(n=5)。 相似文献
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