Li Hanshan

The Study and Design of Anti-Light Interference in PDT

This paper aims at the question about the gunpoint light affection when the photoelectric detection target (PDT) works before the gunpoint. The long rectangular photo detector that have high response and low noise performance is used to expand the field of detecting view and improve the detecting performance. The feature that the light of gunpoint and the signal of projectile are work at the same time in the whole array photo detector was used to analyze and design anti-light interference circuit. Under the condition that the detecting visual field of PDT meet the request, the array photo detector was divided into three parts to distinguish the signal of gunpoint light and flying projectile, analyzed the relation between gunpoint light and the projectile information, the reasonable the detecting circuit in the PDT is designed. It makes the influence of gunpoint light is minimum, and the signal of flying projectile is distinct; the measure is very availability to eliminate the interference of gunpoint light.

Detection and Research on Dental Pulp Fluorescence Signal

The technology of laser induced fluorescence was used to detect the state of dental pulp vitality. The detection device of dental pulp vitality was designed base on the principle that the teeth can be excited the fluorescence in the short wavelength light-source irradiation, and the fluorescence intension has close related with the dental pulp vitality. In this paper, the principle of detection fluorescence was introduced, the transfer fiber was designed, photomultiplier was put forward to gather the reflection fluorescence from the teeth, and the circuit of detection and gather were designed, the influence factor were analyzed; the SCM was used to design the gather system of fluorescence signal, according to the communication principle of SCM and computer, the data of dental fluorescence signal can be processed and displayed in the computer. Through the primary experimentation, the results show that the ill healthy tooth can be distinguished obviously from the healthy tooth.