A CAD/CAE system of the ring-type planetary reducer with small tooth number difference is presented. It is a parameterized CAD/CAE system adopting the object-oriented technique and comprising in itsel
Geographic information systems (GIS) are a widely used tool in urban planning and management. More and more cities and decision-makers require its attributes of promptness, precision and visualization
云南省水文水资源局保山分局是保山市从事水文水资源研究的事业单位,现有在职职工55人,其中高职1人,中职16人,初职27人。辖7个国家基本水文站（其中3个国家重要水文站）,11个专用水文站,50个雨量站,9个水质监测点。拥有全站仪、电波流速仪、PHDO多参数现场监测仪、原子吸
This paper tries to qualitatively analyze land use and cover changes (LUCC) and accompanied soil degradation in China, the data of World Atlas of Agriculture in 1969, Land Cover Data of Asia in 1992 a