To understand the sources and migration pattern of PM2.5 in the Yangtze River Delta (YRD), China, the total carbon (TC) and total nitrogen (TN) concentrations and the corresponding stable isotope ratios (?13CTC and ?15NTN) were determined in aerosol samples simultaneously collected from August 2014 to April 2015 at three different locations (Shangh

Abstract Fracturing is an effective means of improving oil recovery in reservoirs, and controllable shock wave is a new type of fracturing technology.In this paper, firstly, combining a large-scale true tri-axial fracturing simulation experimental device with a pulse type controllable shock wave fracturing rock system, pulse type repetitive control