Weld solidification crack prevention in the laser penetration welding process is essential for the strength of the welded component.The formation of solidification cracks can ultimately be attributed to welding residual stresses, and preventive measures should be taken during welding.In this study, the effects of residual stresses on the laser pene
Abstract Background Oil spills are widespread and can cause devastating environmental consequences.Rapid oil identification is critical to find the origin of the spill, monitor the environment, and lead to informed mitigation measures.The current standard methods in oil spill identification are precise and reliable, but require extensive sample pre
The tidal river network area of the Pearl River Delta uses the ebb-and-flow Low Power Schottky differences between tidal level of the outer river and water level of the inland river to divert clear water for regulation.This is an effective way to improve the water environment of the tidal river network.The central ditch of Hengqin New District is i
Direct election of regional heads allows prospective regional heads to compete directly to become regional heads in local government.The regional government has implemented local democracy if the regional government has held regional head elections.Regional heads can stop or be dismissed according to the provisions of the laws and regulations conce