Research into Haze Removal Method Based on Diffusion and Relative Motion

Abstract

A method for purifying polluted air in large open space was proposed and verified based on concentration gradient diffusion theory and relative motion principle of purifying device to polluted air. As to the sources of particle emitting, the purifying device works as a sink no matter it is moving or not. Both indoor and outdoor experiments have been made. In the indoor experiment, severe haze environment was simulated by fuming. The purifying device was made of metal wire and carbon cloth. The fixed device took 2.7, 6.2 and 13 minutes to reduce the particle concentration in the 7 m farthest corner of the laboratory to 50%, 20% and 0 respectively. By moving the device at 1 m s -1 , the concentration could be reduced to 50% in merely 15 seconds. In outdoor experiment, 23.5% decrease of haze concentration was measured.

Effect of composition‐graded interlayers in double‐heterostructure blue InGaN light‐emitting diodes

“…As for the composition‐graded layer, the fixed polarization‐induced sheet charges spread to a bulk charge defined by where is the volume charge density and P is the total polarization in the grading layer . The utilization of In x Ga 1− x N grading layer could thus be beneficial for the reduction of polarization effect . Besides, it is observed in Fig.…”

“…The composition‐graded layers can be used in lattice‐mismatched semiconductor devices to minimize the dislocation defects and improve the crystalline quality . Moreover, they have also been demonstrated to be beneficial for the release of potential barriers and polarization effect in InGaN optoelectronic devices . Therefore, the InGaN LED structure with graded DH active region could be an appropriate solution to pursue the reduced Auger loss without the cost of degraded crystalline quality.…”

Research Progress of HP Characteristics, Hazards, Control Technologies, and Measures in China after 2013

“…In addition, the "particle-sink" effect can also be applied to remove haze PM. Based on the concentration gradient force, haze PM can change from irregular Brownian motion to strong directional migration to purification device, forming a "particle-sink" relative to the "particle-source" [213,214].…”