The U.S. government on Thursday added 37 Chinese entities to its trade blacklist, citing national security concerns, with 11 of them accused of being connected with a suspected spy balloon that flew over sensitive areas of the United States last year. Entities including companies and research institutions on the list are restricted from doing business with U.S. firms and must gain Commerce Department approval before obtaining goods and technologies from them. Of the 37 entities, the department said 22 were put on the list for their links to China’s efforts to improve quantum technology and for…