WASHINGTON, July 10 (Reuters) – U.S. Treasury Secretary Janet Yellen went to Beijing with no expectations that meetings with China's new top economic officials would immediately ease tensions between the world's two largest economies. There was no breakthrough. And it's far from clear whether the 10 hours of meetings, covering issues ranging from U.S. technology export controls to China's new "anti-espionage" law and other punitive actions against U.S. firms, will do anything to change the relationship's trajectory. But Yellen met her objective of opening communications with her new Chinese counterpart, Vice Premier He Lifeng, and explaining U.S. intentions on a…