The current world pattern is at the beginning of the "Great Chaos" in the 21st century. There are not only constant conflicts at the international level, but also internal contradictions that are breeding and spreading, as well as the unknown mystery of outer space exploration. For every individual in a turbulent environment, how to protect himself and his family is our concern and work goal.
     First of all, in the major international conflicts, we understand that the Russian-Uzbekistan war, the conflict between Serbia and Kosovo, the Taiwan-independent conflict in the Gulf, the conflict between Turkey and the surrounding Arab countries, the Palestinian-Israeli conflict, and so on, are all in progress or in a raging undercurrent. For those who are involved in it, whether soldiers or people, saving their lives is the top priority. In the war, if it is the ordinary people, the probability of being directly hit by bullets or missiles is low. Generally, it is caused by stray bullets or fragments. Such damage can be large or small. How to avoid it? In addition to mastering the escape skills, it is the most appropriate to have a bullet-proof vest with fragments. You can choose steel, iron and other easily found materials for preliminary defense. If there are some conditions, you can prepare several sets of full-body composite protection at home (of course, don't wear it openly, at least put a layer on the outside. Once this kind of protection is considered as special protection, it may be robbed instantly). When dealing with multiple bullets, the steel and iron bulletproof plates are very effective as long as they are thick enough. The disadvantage is that they are heavy, not portable and not personal. Temporary defense is still a good choice. The bulletproof clothing made of composite materials is relatively light in weight, portable and close to the body. The disadvantage is that the material is chemically synthesized, so it has a shelf life. After reaching a certain service life (even if it is not used, it will expire), the fiber material and resin will age and lose efficacy, and the bulletproof function will no longer be. From the material point of view, the main reason for the failure of chemical materials is that the external environment is constantly "invading" the internal molecular structure. If we can directly isolate the air and bulletproof clothing well enough, it is still feasible to improve some service life, or carry out secondary processing after a period of use, strengthen the binding force between fibers again, and improve the fiber strength, modulus, breaking elongation and other indicators, It can also achieve longer bulletproof effect. In short, the principle is like this, and the operation method needs to be explored by everyone. On the other hand, from the development of nature, we can find the answer to any question from nature. Nowadays, bulletproof mainly depends on ceramics and high-strength fibers. Ceramics are hard inorganic substances. There are many inorganic substances, and the strength after hardening is also available. The simplest is the preparation of porcelain, which is the same reason. In terms of high-strength fiber, in addition to chemical synthesis, many people have also done a lot of work on natural fiber. The answer must be yes, but it only takes time. That is to say, in case of an emergency, you should know the principle of our self-made simple bulletproof vest, so that we can achieve a little preliminary defense.
     Secondly, at the level of local minor contradictions, the chaos of Qiang branch is still a few, so the cutting and stabbing of knives should be the concern of ordinary people. In most cases, bullet-proof products must also be stab-proof, and the grade gap is only. There is not much difference in principle. At present, stab-proof products can be very thin and fit, and are suitable for most environments. However, due to the limitations of the knitting method, most stab-proof products can not achieve the level of washing machine care, which will lead to product structure damage and product failure. Therefore, in chaotic areas, it is necessary to prepare some stab-proof clothing. The inner wear style will not have a great sense of load bearing, and can play a certain protective role. Note: Stab-proof is not bullet-proof.
     Finally, I also want to discuss the future personal protective equipment with readers. As we know, Musk's rocket recovery is relatively mature, so the trip to outer space must be the next highlight. Are we the only living body in the exploration of outer space? In addition to life in outer space, we are faced with more complex environments such as rays, meteorites, pressure changes and so on. If we realize interstellar travel when conditions are right, more people will realize interstellar travel and interstellar settlement. It is of forward-looking significance to simulate future personal protective equipment in the environment of high radiation, high cold, pressure changes, etc. for a long time. Here I propose an idea that materials need to have high conductivity. For materials, once they have electron transfer properties, they can be endowed with more energy states and play more functions.       This may be the key problem to be solved after we make the decision of interstellar settlement in the future. In the development of new materials, we hope to do something to be more confident and calm about the future.