Orion: It’s a hot August day with temperatures hovering near triple digits, and a thick coal-smog mixed with exhaust fumes surrounds a city of more than 17 million people. No, this isn’t a bad air day in Los Angeles. It’s worse. Welcome to the Beijing 2008 Summer Olympics, and don’t forget to strap on your dust masks. As Beijing, the air-pollution capital of the world, prepares to host the Olympics for the first time, Chinese government officials are coming up with ideas to improve …