Abstract: An axial-flow heat dissipation fan including a frame, a hub, and a plurality of blades is provided. The frame has an air inlet and an air outlet. The hub is rotatably arranged in the frame. The blades disposed at side of the hub respectively and rotate along with the hub. Each of the blades has a front surface facing toward the air inlet and a rear surface facing toward the air outlet. A surface roughness of the front surface is different from a surface roughness of the rear surface.

Abstract: A method and system that provides a user with precision and accuracy of recommended information that matches the user's personality and behavior by obtaining the location of the user's mobile terminal, determining a target area based on the location, the target area including more than one signal transmission source, each signal transmission source carrying an ID that represents the signal transmission source, and the ID carried in the signal transmission source being transmitted within a target range by using the signal transmission source, obtaining other information from the terminal including user basic information and/or user behavior information and/or user relation chain information, selecting target display information associated with this information from the display information associated with the more than one ID of the terminal, and sending the target display information to the terminal.