中文摘要：

从沙床的沙粒子的早期的运动在被风吹的沙的预言起一个很重要的作用。在这份报纸，当风速度比批评的风速度大时，我们为如下基于风速度变化预言沙粒子的早期的运动建议了一个新方法，如果沙粒子上的全部的推动比批评推动大，沙粒子的早期的运动将发生，否则如果不。从在滚动并且上升的模式的乘火车的分析，而且，我们来到下列结论。当如果平均的风速度被用来判定沙粒子的早期的动议，平均的风速度比批评的风速度小时，一个人将低估从床跳的沙粒子的数字，如果即时风速度被用来判定沙粒子的早期的运动，一个人将过高估计从床跳的沙粒子的数字；当平均的风速度比批评的风速度大时，一般水准或即时风速度被用来判定沙粒子的早期的运动，一个人将过高估计从床跳的沙粒子的数字。

英文摘要：

The incipient motion of sand particle from sand bed plays a very important role in the prediction of windblown sand.In this paper,we proposed a new method for predicting the incipient motion of sand particle based on wind speed fluctuation as follows,when the wind speed is larger than the critical wind speed,if the total impulse on sand particle is larger than the critical impulse,incipient motion of sand particle would take place,otherwise if not.Furthermore,from the analysis of entrainment in the rolling and lifting modes,we come to the following conclusion.When the average wind speed is smaller than the critical wind speed,if the average wind speed is used to judge the incipient motion of sand particle,one will underestimate the number of sand particles jumping from the bed,if the instantaneous wind speed is used to judge incipient motion of sand particle,one will overestimate the number of sand particles jumping from the bed;When the average wind speed is larger than the critical wind speed,either the average or the instantaneous wind speeds is used to judge the incipientmotion of sand particles,one will overestimate the number of sand particles jumping from the bed.