引言 谷粒受到环境变化的影响时,内部会产生裂缝,谷壳会破裂。场土变干,运输,以及人工干燥时发生的气温和空气相对湿度条件的变化,都会导致谷粒的物理损伤。可以推测,由于温度梯度和水分梯度,在谷粒各部分引起程度不同的膨胀和收缩,将在谷粒内部产生应力。因为热传递速率比水分传递的速率高得多,温度梯度和水分梯度的综合效应不好确定。Hcndcrson观察了大米内部的裂痕沿短轴从中心向边上扩展的过程。他指出,在变干的早期阶段,其内应力主要是由温度梯度引起的。Strcmmer INTRODUCTION When grain is affected by changes in the environment, there is a crack in the inside and the chaff breaks. Field soil drying, transportation, and artificial drying occurs when the temperature and air relative humidity conditions, will lead to physical damage to grain. It can be speculated that due to the temperature gradient and the water gradient, different degrees of expansion and contraction are caused in various parts of the grain, stress will be generated inside the grain. Because the rate of heat transfer is much higher than the rate of moisture transfer, the combined effect of temperature gradients and moisture gradients is poorly defined. Hcndcrson observed the extension of the crack in the rice from the center to the edge along the minor axis. He pointed out that in the early stages of drying out, the internal stress is mainly caused by the temperature gradient. Strcmmer