By analyzing the amplitude and phase spectrum of the harmonic waves produced by heat wave transmission,the heat conductivities of good conductors with heat loss were obtained.The instruments were simplified,the system errors were eliminated,and the effects of heat convection and radiation could be ignored.
The necessity and feasibility of Chinese-French bilingual teaching in physics experiments was discussed.Besides,the current practice of Chinese-French bilingual teaching in physics experiments in Sino-French Engineer School of Beihang University was also introduced.Furthermore,the problems encountered in bilingual teaching were discussed and some countermeasures were put forward.
When Na2S2O3 reacts with dilute hydrochloric acid,insoluble solid sulfur molecules emerge in the solution.The diameter of the sulfur molecules is less than the wavelength of visible light.Some sulfur molecules can agglomerate to form particles with their diameters similar to or bigger then the wavelength of visible light.If white light passes through the liquid during the reaction,Rayleigh scattering and Mie scattering can be observed.In Rayleigh scattering,the light polarization can also be observed.
