The research on explosion suppression effect of aluminum alloy explosion-proof materials cleaned by ultrasonic

Premixed gas explosion pipe system was established to study the change rule of explosion pressure and pressure rise rate of 10% methane/ air premixed gas under four condition that no material was filled, used material was filled, new materials was filled and cleaned materials was filled in explosive pipe. The results show that compared with the used material and cleaned material, the average maximum explosion pressure was reduced by 21.62% and the average pressure rise rate decreased by 84.80%. The results show that the suppression performance of used aluminum alloy explosion-proof materials improved greatly after the used materials is cleaned

Does the Legal System Affect the Cost of External Financing? Evidence from IPO Underpricing of Foreign Firms Listed in U.S. Stock Markets

To study the effect of the legal system on the cost of external financing, we examine the degree of underpricing of the IPOs by foreign companies listed in U.S. We find that firms from highly corrupted countries have larger IPO underpricing. The quality of the home-country public law enforcement reduces the degree of IPO underpricing. In particular, the criminal sanction for violations of securities laws is the most significant factor in reducing underpricing. The evidence shows that even when a non-U.S. firm meets sophisticated U.S. regulations and goes public in a U.S. exchange, the degree of underpricing is still influenced by the legal and judicial system in the home country. Following La Porta et al. (2000a), we provide evidence against the functional convergence hypothesis (Coffee, 1999 and 2002)