Terrain plays a critical role in the selection of cropland. As a physical and geographical element of the landscape, terrain is an important limiting factor in land use change and has a strong influence on human activities. The objectives of this study are to investigate the topographic characteristics of cropland-related transformations in China during the… (More)
BACKGROUND In China, over 80% of all work-related deaths in the mining industry occur in coal mines and human factors constitute 85% of the direct causes of coal mine accidents, which indicates that significant shortcomings currently exist in the safety behavior management of Chinese coal mine workers. We aimed to verify the impact of human psychological… (More)
Terrain, an important limiting factor in land use change, strongly influences agricultural productivity. This study investigated the topographical characteristics of agricultural potential productivity of cropland transformations in China during the first decade of the 21st century, and explored the impacts of cropland transformations with different… (More)
In the title compound, C(20)H(20)N(4)O(4), the complete molecule is generated by a crystallographic centre of symmetry. The conformation is stabilized by two intramolecular C-H⋯N links.