cloud n. 1.云。 2.云状尘埃、烟(等);(鸟、虫、飞机等的)大群,大队。 3.(水晶等的)雾斑,(镜子等上的)云斑。 4.(显出疑惑、不满、悲哀等的)阴郁脸色;遮暗物,阴影。 5.(编结的质地轻柔的)女围巾。 6.(名誉等的)污点。 a cloud of steam 雾气。 a cloud of dust 一团尘雾。 a cloud of birds (像云一样的)一大群鸟。 a cloud of arrows 一阵稠密的乱箭。 a cloud of words 暧昧话。 be lost in a cloud 烟消云散。 be lost in the cloud 隐入云中。 blow a cloud 〔俚语〕抽烟,吞云吐雾。 cast a cloud (up)on 在…上投下一层暗影。 Every cloud has a silver lining. 乌云朵朵衬白底,黑夜漫漫有尽头;任何困难情况都有可盼的希望。 drop from the cloud 从天而降。 (lose oneself) in the clouds 1. 在云层中;[喻]虚无飘渺。 2. (人)空想,呆想,茫然;(事情)不落实,不现实。 kick the clouds 〔俚语〕被绞死。 on a cloud〔俚语〕满心欢喜,兴高采烈。 under a cloud 不得意,失宠,受嫌疑,遭白眼,处困境。 under cloud of night 趁黑。 wait till the clouds roll by 等乌云散开,等时机到来。 vt. 1.使乌云密布,使变黑暗。 2.在(心)上投下苦恼的[忧愁的]暗影,使心情黯然。 3.破坏(名誉),损伤(友谊)。 face clouded with anger 因为生气而面色阴沉。 vi. 1.云层密布,变黑暗;(镜面等)布满云斑。 2.(心)变忧郁,变黯然(over, up) (脸色)阴沉下来。 adj. -less 无云的,晴朗的。 n. -let 微云,朵云,片云。
The mechanism of the downburst formation was also investigated based on the cloud microphysics of the simulated storm and it was found that this downburst was primarily produced by hail loading , and enhanced by hail melting and rain evaporation . and the loading and the melting of hail played a very important role in producing the downburst . the gale at the surface was caused by the severe downburst 从云微物理学角度分析了此次局地性大风的形成原因,认为由高空冰雹粒子的拖曳产生的负浮力作用是促发强下沉气流产生的主要原因,其次是冰雹的融化和雨水蒸发冷却对下沉气流起加速作用,冰雹的拖曳和融化作用对下沉气流具有决定性的作用。