The U.S. is ratcheting up restrictions aimed at holding back the development of China’s semiconductor industry. The U.S. said it would add China’s most advanced memory-chip manufacturer to an export blacklist on Thursday, ratcheting up restrictions aimed at holding back the development of the country’s semiconductor industry. The addition of Yangtze Memory Technologies Co. to the Commerce Department’s so-called entity list could further disrupt the company’s business following an earlier round of restrictions in October that led chip-manufacturing equipment companies to pull out staff based at its facilities and pause their activities there. The blacklisting is due to take effect…