黄河滩沙尘粒径分布及形状的测量

Measurements of Diameter Distribution and Shape of Sand at the Beach of the Yellow River

根据毫米波传播特性研究的需要,给出了黄河滩试验区的沙尘粒径分布及形状的测量方法和测量结果。统计分析结果表明:沙尘粒径分布服从于对数正态分布。参数(lnD)的均值 m 的范围从(—2)到(—3);参数(lnD)的标准偏差从0.3到0.7。同时还给出了沙尘的体密度 N,从1×10~5到4×10~6(1/m^3)。沙尘的等效粒径为0.127mm。沙尘粒子的形状主要分为滚圆形,次滚圆形和次棱形三种,其比例分别为22.8%,21.3%和55.9%。最后利用上述的测量结果和沙尘的复介电常数的测量值,估算出3mm 波在沙尘中传播衰减。这一结果与黄河滩上沙尘中衰减测量基本吻合。

A measuring method for and results of the diameter distribution and shape of sand at the beach of the Yellow River are presented in this paper.It is shown that the diameter distribution of sand obeys a Log—Normal law;the average value of parameter (lnD)lies in the range from(-2)to(-3);the mean standard deviation of the parameter(lnD)lies in the range from 0.3 to 0.7;the concentration of sand lies in the range from 1×10~5 to 4×10~6(1/m^3);and the effective diameter of sand is 0.127mm. The shape of sand particle is divided into sphere,subsphere and subrhomb with percentages 22.8%,21.3% and 55.9%,respectively.Finally,the specific attenuation due to sand at frequency of 93GHz are calculated by the results of the parameters of sand and measured complex permittivity of sand.The immediate measured result of the specific attenuation due to sand at the beach of the Yellow River is closed to the calculated result.