针孔摄象镜头遥控系统的设计

针孔摄象镜头用于监控系统。该镜头和摄象机、监视器、控制电源配套组成一个完整的监视系统。针孔摄象镜头遥控系统主要由控制电源、阻尼机构和光阑机构组成。该系统的工作原理是:当外界景物的亮度随机变     

An Empirical Study on E-commerce Service in the Western China’s Tourism Industry

In the strategy of developing the Western China, the western region cover 12 provinces, cities and autonomous region: Sichuan, Yunnan, Guizhou, Tibet, Qinghai, Xinjiang, Shaanxi, Gansu, Inner Mongolia, Guangxi, Chongqing, Ningxia as well as Tujia-Miao Autonomous Prefecture of Xiangxi in Hunan, Tujia-Miao Autonomous Prefecture of Shi’en in Hubei and Korean Autonomous Prefecture of Yanbian in Jilin[1]. The Western China has abundance of natural and cultural tourism resources. Since…