The project of returning farmland to forest is a new project of increasing farmers' income, ecological efficiency and

benefiting the country. The key to the success of returning farmland to forest project is to strictly control the key technologies such as regional planning, forest species selection, tree species selection, good seedling, structural configuration, meticulous soil preparation, serious planting, tending and management. According to the actual

situation of Yuanling County, suitable for the tree, choose the market prospects, fast-growing tree species afforestation,

reasonable adjustment of forest structure, ecological benefits and economic benefits simultaneously, take high-

quality high-yield and efficient forestry development. Returning farmland to forest project has played huge ecological benefits, economic and social benefits.

This paper describes the significance, content, progress and corresponding basic theory and experimental research methods of micron/nanometer scale thermal science and engineering, which is one of the latest cutting-edge disciplines, and analyzes the effects of micron nanometer devices on the scale effect series of challenging hot issues, discussed the corresponding emergence of some new phenomena and new concepts, pointed out that the micron/nano thermal science aspects of the recent development of several types of theory and experimental technology success and shortcomings, and summed up a number for the exploration of the new ways and new directions, especially on some typical micron/nano-thermal devices and micro-scale biological heat transfer in some important scientific issues and their engineering applications were introduced.