A temperature control system for ring-down cavity is developed.The temperature control box with silicone heating plate on the inner wall is designed firstly,which the ring-down cavity is placed in.The internal temperature distribution is simulated.The finite element analysis and parametric scanning are carried out to get the optimized distribution and power of the heating plate to ensure the temperature uniformity along the light-transmitting part of the cavity.According to the simulation results,the actual box and heating plate are fabricated.Then,the hardware circuit system including temperature sampling module,control module and drive circuit module are designed with PID control algorithm as the core,and the corresponding control algorithm is developed to precisely control the cavity temperature change.After the precision temperature control system is completed,the standard deviation of the temperature variation along the light-transmitting part of the ring-down cavity is less than 0.01 ℃ in 8 hours.

光腔衰荡光谱技术依赖于气体分子常数测量气体成份量,有望成为新一代基于自然常数的气体成份量基准方法.本文详细介绍了国内外研究机构对于光腔衰荡光谱法在气体成份量测量领域的研究现状,并在此基础上设计出一套基于Pound-Drever-Hall(PDH)锁频技术的光腔衰荡光谱测量装置,旨在完善目前实物计量标准的局限性.

Based on the current calculation method of annual performance factor(APF) for room air conditioner stated in the GB 21455-2013 Minimum allowable values of the energy efficiency and energy efficiency grades for variable speed room air conditioners,making use of PTC Mathcad Prime software,the influences of rated total cooling capacity,rated half cooling capacity,rated total heating capacity,rated half heating capacity,rated low-temperature heating capacity and the corresponding power on the APF are analyzed.The conclusions can provide reference for the design and development of room air conditioners,with theoretical value and practicable value.