Kuohai Zhang

Experimental Study on Laser Propulsion of Air‐breathing Mode

A series of experiments were done to investigate the effect of laser parameters on laser propulsion. A high power high repetition rate TEA CO2 laser was employed in the experiments. The output energy of the laser is up to 15J and the repetition rate is up to 150 pps. The light craft models in the experiments were two parabolic aluminum shells with the exit diameter of 50 mm, the focus lengths were 5mm and 10mm respectively. The effect of the laser’s repetition rate on coupling coefficient was mainly investigated. The value of optimal repetition rate for laser propulsion of air‐breathing mode is discussed. On the basis of our investigation, a setup of laser propulsion demonstration experiment was designed. And laser‐powered free flight demonstration was realized. The 4.2g parabolic craft with 10mm focus length was boosted by the TEA CO2 laser to the altitude of more than 2.6m (limited by the ceiling of the laboratory) in a flight lasting 1.75s. The output pulse energy is 13J and the repetition rate is 50 pps.

AUXIN RESPONSE FACTOR3 plays distinct role during early flower development

ABSTRACT AUXIN RESPONSE FACTOR3 (ARF3), one of the auxin response factors family of transcription factors, is well characterized by its functions in polarity identification and organ patterning. We recently demonstrated that ARF3 plays important roles in floral meristem (FM) maintenance and termination by regulating cytokinin biosynthesis and signaling. However, the relationship of its multiple roles in differently developmental stage is still unclear. Here, we present data that ARF3 plays distinct roles during early flower development that are different from its roles in organ polarity determination and pattering. Thus, our findings shed light on the functional diversity of one specific transcription factor in plant development.

Investigation on momentum coupling coefficient for a parabolic shell

Momentum coupling coefficients of TEA CO2 laser pulses for a parabolic aluminum shell were investigated. Momentum coupling coefficients were measured with a pendulum in a chamber, the energy of the incident laser pulse was varied from 8.3J to 50.9J, and the gas pressure in the chamber was changed from 100 kPa to 20 kPa in our experiments. Experimental data were analyzed thoroughly. It was found that the coupling coefficients under the air pressure of 100kPa decreased very slowly from 242 N/MW to 170 N/MW for the incident energy from 50.9J to 15.1J but decreased sharply for the energy between 15.1 J to 13.8 J. And it was different for the air pressure below 100 kPa. Indoor free flight of our parabolic shell was also analyzed, coupling coefficients and some other parameters were deduced from the experimental data.