电影《731》海报上的防毒面具，实物什么样？总台记者实地探访

Core Viewpoint - The film "731" premiered globally in Harbin, depicting the inhumane biological warfare experiments conducted by the Japanese Unit 731 during the Second Sino-Japanese War, particularly focusing on their secretive human experimentation practices [1][2]. Group 1: Historical Context - The film illustrates the secret facilities used by Unit 731 for human experimentation and the development of biological weapons, which were core to their operations [2][4]. - In mid-August 1945, Unit 731 received orders to retreat and destroyed their administrative and living areas, but they prioritized the destruction of their experimental facilities [4]. Group 2: Facilities and Experiments - The main site for biological research and human experimentation was the "Sifang Building," which measured approximately 151 meters in length and 101.53 meters in width, featuring special prisons for holding experimental subjects [5][10]. - Unit 731 conducted over 50 types of experiments, including anthrax, plague, and live dissections, with data being shared with the Japanese Army Medical School for further research [12]. Group 3: Victims and Evidence - Victims were often transported through a coordinated effort involving the Japanese military and police, with 1,549 individuals confirmed to have been sent to Unit 731 for experimentation [15][17]. - Extensive archaeological excavations have uncovered over 1,000 artifacts related to Unit 731, providing substantial evidence of their crimes [9][19].