PROBLEM TO BE SOLVED: To provide an oil-free vacuum pump in which toxic gas is diluted if the toxic gas is condensed in a compression stroke for vacuumization of the toxic gas contained in a container. ;SOLUTION: In an oil-free vacuum pump which discharges compressed fluid in a pump main...
俗话说,民以食为天.作为普通大众,生活就是柴米油盐酱醋茶交织成的交响乐.山东饮食文化历史悠久,博大精深,色,香,味俱全的美食数不胜数.在美丽的鲁西南地区,就有很多让人垂涎欲滴,回味无穷的美食,让三餐四季充满人间烟火气.一餐早饭,唤醒味蕾有人说,鲁西南人的一天是从喝糁开始的,当整个城市还在酣睡着,糁的香气已...