Scipher, a technology development and licensing company based in London, and PicVue Electronics Ltd., a Taiwanese supplier of liquid crystal displays, announced they are constructing a mass-production microdisplay plant in Taiwan.   . . .   Semiconductor Equipment and Materials International (SEMI) has established a China regional office in Beijing. SEMI officials, industry representatives and government leaders gathered at a reception at the Hotel Kunlun last week to commemorate the announcement.