At the beginning of 2121, there was bad news, and the COVID-19 epidemic in Hebei Province came back. In order to control the spread speed of COVID-19 epidemic to the greatest extent, better requirements were put forward for medical staff to complete the nucleic acid detection of the city's population of 11 million as soon as possible. Due to the heavy workload of detection, the number of people tested in hospitals was limited every day. Shijiazhuang built a fire eye laboratory in Hebei Gymnasium in just 11 hours, which can be used every day. Many netizens have noticed that the construction of the fire eye laboratory is actually a large inflatable tent, and the internal space of each tent is more than 71 square meters, but the news says that these tents are negative pressure, so many people don't understand. How do these tents achieve both inflation and negative pressure? Positive pressure and negative pressure

We live on the earth, and the basis of our existence is fresh air. The earth is surrounded by the atmosphere, and the concentration of air decreases with the increase of height, at the same time, the atmospheric pressure will become lower and lower; On the contrary, the atmospheric pressure at the lower part is higher. We generally set the atmospheric pressure at sea level at 1℃ and latitude at 45 degrees as 1 standard atmospheric pressure. Air is a fluid and naturally flows from a place with high pressure to a place with low pressure. Suppose that we build a house at sea level, and the atmospheric pressure in the house is greater than 1 million Pa, then the air in the house will flow to the outside, which is positive pressure; On the other hand, if the pressure outside the house is greater than the pressure inside the house, then the air will flow into the house, which is negative pressure; If the doors and windows are open, air can enter and exit freely, that is, at equal pressure or normal pressure. The function of positive pressure and negative pressure

There are always impurities in the air, such as dust, toxic chemical gases or bacteria. We all like clean air, so if there is dust outside the house, we must find a way to keep it from entering the house. This way is to turn the house into a positive pressure area, so that the polluted air outside cannot enter the house. By the same token, if there is a risk of infection in the air of a ward, vehicle or laboratory, we can turn it into a negative pressure, so that the air that may be polluted inside cannot escape and pollute the air outside again. How can people inside prevent being infected? This requires them to do more strict protection and wear more comprehensive protection facilities, so that they can not directly inhale the air that may be polluted indoors. The advantage of inflatable tent is that it saves the floor space during storage and transportation, and it can be opened quickly. As long as it is blown up by a blower, it can become a big house, which plays a very important role in this special period. ?