In december 2024, the 12th shanghai city coptic contest was held on the theme “scientific love for science”. The aim of the competition is to increase public interest in and understanding of science and to promote the development of a cadre of science instructors。
After intense competitions, the shanghai states sponsored a competition in the system. We will re-advertise the award-winning work in the “break up knowledge” column, which will feature the award-winning contestant zhu zhengqing's brilliant lecture on underground guardian — people's defense works。
Underground guardians — human defense engineering
Let's talk today about the underground guardians — people's defense works — at our feet。
What's human defense
Article 18 of the people's republic of china's law on people's air defence stipulates that people's air defence works include underground protective structures built separately to secure the sheltering of war-timers and goods, the command of people's air defence, medical assistance, etc., and the basements used for air defence during wartime constructed in conjunction with ground buildings。
Why did you hide in the defense
In modern warfare, regardless of the type of air attack, the resulting harm to humans is largely in the following forms — explosive shock waves, heat radiation, nuclear radiation and biochemical poison gas. In the case of nuclear weapons, for example, nuclear weapons have been used in five ways, with shocks accounting for 50 per cent of the total damage. When nuclear weapons explode in the air, a high-pressure, high-temperature air mass is formed in an instant. This air mass expands rapidly and compresses the air around it, creating an extremely destructive air shock. These shock waves spread around at 340 metres per second, destroying instantaneously all the objects they touched. The impact is so powerful that it can overturn buildings, destroy roads and bridges and easily cause serious harm to the human body. You know, when the pressure is over 1 atmospheric pressure, it can be up to 4,000-5,000 kg of the force of the body, which is equivalent to a sudden impact on a heavy truck。
In the face of such devastating storms, human defence works can safeguard the lives and property of the population in times of distress. They are usually malls, garages, transportation hubs and, when war strikes, guardians of the safety of people and goods。
What's the difference between human defense and normal basements
I'm sure you'll be wondering what's the difference between human defense and normal basements? In short, it's a promax and a regular version of a mobile phone. First, the front is different. This big iron door is actually the first line of human defense work, and it's called a closed door. It is about 20 centimetres thick, the threshold usually consisting of solid, integrated steel, with seals of high-flexible material between the doorknobs and the door frames, often opening up in daily life to facilitate access to people and vehicles, and protecting the population from air strikes, which are closed to shield not only the shock wave but also from the intrusion of harmful substances such as nuclear radiation, biochemical gas and so forth。
Second, building standards are different. The ceilings, side walls and floors for human defence work are thicker than the normal basements. In order to make the structure more robust, plum-forming bars are set up at the top and bottom, and are drawn down by hooking. Even if the concrete is broken, the steel web is still able to ensure that it does not fall. Its ability to withstand shock wave pressure is about six times that of an ordinary basement. In addition, human defence works are equipped with well-equipped protective equipment (e. G., proliferation rooms, filtration systems, washing systems to withstand blast waves and biological and chemical weapons attacks). These are only a small part of the human defence works, which are not individual building units, but a whole set of systems and a complete life work。
Where's the defense
How to find and understand the defense works
There are two ways to locate and understand people around them: look at the signs and look at the maps。
Look at the sign, it's a human defense project sign, a logo and a civil defence project sign. Many of the residential districts in shanghai where human defence works have been built have been set up, and it may have come to your attention that some roads, sub-districts and public buildings have been marked with such a “civil defence project” sign, orange white, with an arrow and a man-made running pattern。
Checking the maps, shanghai took the lead in launching online “civil defence maps” throughout the country and can search for sites in the “on request” app. The use of online “civil defence maps” also allows for the identification of air raid alarm sounds, the identification of emergency shelters, and knowledge of human preventive education facilities. The latest version of the civil defence map 2. 0 also introduced a card-keeping function, which is open to regular access, experience of civil defence maps and information about the location of human defence engineering。
“at times, there is no sense of danger”. The human defence works built in conjunction with the pyramids have long been integrated into our daily lives, woven into a vast network of protections, creating indestructible shields。
