土地沙化是青海高原面临的最严重的生态问题之一.沙化土地主要分布在柴达木盆地、共和盆地、青海湖环湖地区、黄河源区和长江源区.其中青海湖周边地区沙漠化土地是生态建设的重点和难点.因此,在此区域开展治沙造林模式示范,人工植被与气候、土壤环境的相互作用机制等研究,不仅对青海湖周生态环境保护和建设有重要意义,而且对青海湖区社会经济发展的影响深远,同时可以为高寒沙区的防沙治沙提供技术支撑和科学依据,并为沙漠化防治规划提供理论支持.

In this paper, the grain size characteristics of 0-60 cm soil depth in Gonghe Basin, Qinghai Province were studied under five mechanical sand barriers for three years.The results show that: The types of sand barriers have obvious influence on the composition and distribution of soil particles.NT and SH soils are mainly fine sand and extremely fine sand, with high clay and silt content, which can better improve the soil structure and particle size distribution of mobile dunes; There are differences in the relationship between soil fractal dimension and particle size content of each sand barrier type, Among them, the correlation between soil grain content and soil fractal dimension of GLS was the highest.

针对目前主流的4类PLC实验教学设备在应用中的局限性,开展了自制PLC实验教学设备的尝试,开发了基于S7-200 PLC和组态软件的机器狗运动控制系统.文中介绍了机器狗的Solidworks图、机械结构及运动原理,阐述了基于S7-200 PLC和组态软件的机器狗控制系统硬件组成,提供了机器狗运动控制PLC程序设计主程序流程和关键程序设计要点,并给出了组态程序设计界面和组态程序及通信设置的关键要点.实际完成的控制系统不仅实现了机器狗的协调、稳定动作,而且由于加入了触摸屏的组态控制方式,实现了机器狗的双模式运动控制.