Background: To help ensure roadway safety, the federal government mandates trucking companies to conduct pre-employment urine drug tests before allowing drivers to operate a commer- cial motor vehicle. Unfortunately, urine testing has a short detection window and is easily thwarted, leading some...

The continuous supply of reliable and affordable energy sources is crucial for driving a nation's economic activities. The phenomenon of continuous energy supply at affordable prices is called energy security. To date, more than two-thirds of the global energy demand is met by non-renewable...

In this study, thermal interface material is used in photovoltaic-thermoelectric coupling device to enhance the utilization of solar energy. An operating system including cooling equipment is established. The output performance evolutions of PV–TE coupling device are carried out based on...

The classic third degree price discrimination (3PD) model requires the knowledge of the distribution of buyer valuations and the covariate to set the price conditioned on the covariate. In terms of generating revenue, the classic result shows that 3PD is at least as good as uniform pricing. What...

Whether maintaining a close relationship with China can benefit economic performance in the postpandemic era is a crucial concern for countries around the world. This study employs the difference-in-difference (DID) model and propensity score matching to estimate the impact of connecting people...

As the world's largest importer, trading of iron ore occupies a pivotal position in China's international trade. In order to seek the decision power of deciding the price for iron ore, China's Dalian Commodity Exchange (DCE) listed iron ore futures in October 2013,which has become the world's...