The result of the second model of ecological potential was less than zero near the U. pumila, as the distance increasing to field source ecological potential became positive and then negative again; 生态势模型Ⅱ的结果是在距离家榆较近区域生态势小于零,随着距离的增加,生态势转变为大于零,而后又小于零;
Because the antenna of a mobile handset is so near to a human head, that is situated around the field of the induction and the radiation, its radiation of the microwave might be strong enough to make some potential hazards on the head. 手机在工作时,由于天线距离人头部很近,头部处于近场感应和辐射场范围内,足够强的微波辐射可能对人体头部组织产生潜在的危害。