Aclinic tone and assurgent tone take second place.Katabatic tone is always the shortest tone.

一个声格中一般曲折最长，平次之，降最短。

For blower fan coil,adopting local drop ceiling when they are setting with new wind,but adopting a manner of katabatic wind when they arn’t setting with new wind.

对于风机盘管，加新风的部分采用部吊顶，不加新风的部分采用下送风的方式。

Such results are gotten: (1) Due to the unique topography the wind of Beijing area during the day time is southern anabatic wind and in the night is northern katabatic wind in summer.

(1)北京区边界层风场受西北特殊地形的影响,夜间低层大气流场常表现为由北向南的下坡风,白天逐渐转为由南往北的上坡风。