Can I get a voa visa in Beijing . Arriving from USA

No, unfortunately, this is not possible. If you want to travel to Beijing visa free, I advise you to rely on 144 hour visa free transit. You can enjoy this scheme by taking a flight from one country to Beijing and then exiting from Beijing to a third country or eligible territory. For example, you can create the following itinerary:

US - Japan - Beijing - US

As you can see, immediate points before and after Beijing have to be in two different countries or eligible territories (eligible territories: Hong Kong, Taiwan and Macau). If you do like this, you can stay in wider Beijing area for 144 hours visa free.