【题名】: Cooling of US Midwest summer temperature extremes from cropland intensification 【期刊、年、卷、期、起止页码】:Nature Climate Change 6, 317-322 (2016) doi:10.1038/nclimate2825 【全文链接】:http://www.nature.com/nclimate/journal/v6/n3/full/nclimate2825.html 注明:需要在线版全文,谢谢,包括Methods部分