President Donald Trump has blocked a Chinese-linked firm, HieFo Corp, from acquiring certain semiconductor assets of American company Emcore Corporation, citing national security concerns. An executive order prohibits HieFo, described as controlled by a Chinese national, from holding interests in Emcore's digital chip and wafer fabrication businesses. HieFo has been directed to divest these assets within 180 days, with the Committee on Foreign Investment in the United States (CFIUS) overseeing the process.