No abstract

No abstract

No abstract

Ranged-resolved profiles of atmospheric turbulence are necessary and important for many applications in astronomical and adaptive optics communities. In order to characterize the vertical atmospheric structure in field, a technique is put forward to remote sensing ranged-resolved profiles of atmospheric turbulence by combined with laser guide stars and differential image motion method. Laser guide stars are formed at several successive altitudes by projecting pulsed laser, returned signals of images are received by a optical system with two receiving telescopes, and variance of centroids distance is derived from the images with two spots at the same altitude. So, based on a inversion algorithm, atmospheric turbulence profiles are retrieved from differential image motion variance of distance of centroids at various altitudes. The structure constants of refractive index of atmosphere range from 10-14m-2/3 at lower altitudes to 10-16m-2/3 at higher altitudes are remote sensed experimentally. The results show it is a effective method that combined laser guide stars with differential image motion method and could sense atmospheric turbulence profiles remotely in real time.

In the three-phase four wires system, the neutral line is uncharged under normal circumstances, because any point of the neutral line and the earth are of the same potential. However, when the zero line is disconnected, the neutral point on the load side will generate displacement voltage. At this time, if people touch the broken zero line, the current will form a path from the phase line load zero line human body zero point phase line, which is extremely dangerous and the rise of zero line voltage will also cause damage to electrical equipment. In order to solve the harm of zero line fault, this paper puts forward a zero line fault early warning device, which includes voltage acquisition, logic judgment ,attention device and telecommunication equipment, This device can effectively detect the fault points with poor zero line contact, alarm the fault, prompt the staff to check, reduce economic losses and casualties, and improve the safety of power use.