Costume dramas attract huge audiences in China for their sensational soap opera themes, love affairs and murder plots that draw on a nostalgia for China’s imperial past. New trends and breakthrough thinking in politics, science, technology, business and culture. It’s futurism at its best. As Beijing celebrates the 70th anniversary of communist rule, its vast TV industry is feeling the pinch.  With full-size replicas of palaces from China’s imperial past, the world’s largest film studio is normally teeming with actors making historical costume dramas that are wildly popular with the country’s television audiences. But as the Communist Party prepares for the 70th anniversary of the establishment of the People’s Republic of China on Oct. 1, Hengdian World Studios, a complex covering 11 square miles in the country’s east, is eerily quiet. China’s top media regulator last month announced a 100-day ban on broadcasts of dramas judged to be “entertainment-focused,” singling out costume dramas, which celebrate what the party sees as the country’s decadent pre-communist past, and “idol dramas” — soap operas starring celebrities. Instead, the National Radio and Television Administration o...