In this paper, an introduction is given of the fractal theory anti its application to the description of the surface condition. Moreover, a simulation is made on the gauss surface, with the root-mean-square height and...In this paper, an introduction is given of the fractal theory anti its application to the description of the surface condition. Moreover, a simulation is made on the gauss surface, with the root-mean-square height and correlation length as the basic parameters, to draw the graph of the surface condition for the purpose of calculating by the method of MC the spatial scattering intensity distribution in different incidence angles of different patterns on a rough surface in the constraint condition of Kirchhoff approximation. Finally, a measurement is made on the surface BRDF of granite by means of experiment, and a comparison is made between the academic values and the experimental values.展开更多
The Brownian motion of a polystyrene bead trapped in a time-sharing optical tweezers （TSOT） is numerically simulated by adopting Monte-Carlo technique. By analyzing the Brownian motion signal, the effective stiffnes...The Brownian motion of a polystyrene bead trapped in a time-sharing optical tweezers （TSOT） is numerically simulated by adopting Monte-Carlo technique. By analyzing the Brownian motion signal, the effective stiffness of a TSOT is acquired at different switching frequencies. Simulation results confirm that for a specific laser power and duty ratio, the effective stiffness varies with the frequency at low frequency range, while at high frequency range it keeps constant. Our results reveal that the switching frequency can be used to control the stability of time-sharing optical tweezers in a range.展开更多
文摘In this paper, an introduction is given of the fractal theory anti its application to the description of the surface condition. Moreover, a simulation is made on the gauss surface, with the root-mean-square height and correlation length as the basic parameters, to draw the graph of the surface condition for the purpose of calculating by the method of MC the spatial scattering intensity distribution in different incidence angles of different patterns on a rough surface in the constraint condition of Kirchhoff approximation. Finally, a measurement is made on the surface BRDF of granite by means of experiment, and a comparison is made between the academic values and the experimental values.
基金supported by the National"863"Project of China(Nos.2007AA021811 and 2007AA021809)the Funds of the Chinese Academy of Sciences for Key Topics in Innovation Engineering(No.KJCX2-YW-H-10)the Innovation Research Fund for Graduate Students of USTC.
文摘The Brownian motion of a polystyrene bead trapped in a time-sharing optical tweezers （TSOT） is numerically simulated by adopting Monte-Carlo technique. By analyzing the Brownian motion signal, the effective stiffness of a TSOT is acquired at different switching frequencies. Simulation results confirm that for a specific laser power and duty ratio, the effective stiffness varies with the frequency at low frequency range, while at high frequency range it keeps constant. Our results reveal that the switching frequency can be used to control the stability of time-sharing optical tweezers in a range.
