The ionosphere is an important component of space weather, which is between 60 and 1000 km above ground level. The ionosphere is an important factor affecting the military communications, positioning and navigation, mainly through the influence of radio wave propagation. When a strong solar flare occurs, the electron density in the ionosphere increases dramatically, which often leads to a complete interruption of communication and a decline in positioning and navigation accuracy. It can produce several thousand meters of error in determining the position of the object. In the missile test equipment, the power remote control safety system, the pyroelectric resistance tester and the electrical system testing equipment are easily affected by external factors. The monitoring system is a system of continuous or intermittent monitoring of some of the technical parameters and conditions that must be maintained within a certain limit after the missile system is prepared and launched by instrument or special technology, as well as the system of guided missile transmission instruction and monitoring control.
3.4 harm to the human body
Electromagnetic waves can interfere with the biological electricity of the human body, especially interfere with EEG and ECG, thereby affecting the normal function of the brain and cardiac activity. It is probably one of the causes of leukemia in children. Medical research has proved that in a long-term environment of high electromagnetic radiation, blood, lymph and cell protoplasm change. Second, it can induce cancer and accelerate the proliferation of human cancer cells. 3. The influence of human reproductive system is mainly on the decrease of male sperm quality, the occurrence of spontaneous abortion and fetal malformation. (4) can lead to children's mental disability. Affecting people's cardiovascular system, characterized by palpitations, insomnia, some female menstrual disorders, bradycardia, reduced heart rate, disintegration of sinus heart rate, leukocyte reduction, and immune function decline. 6. There is a bad influence on people's visual system. Because the eyes are the sensitive organs of the human body to electromagnetic radiation, excessive electromagnetic radiation can cause visual loss and cataract.
3.5 harmful factors
The interaction between the electromagnetic wave and the organism can be absorbed by the material of the organism, but not in all cases, people are injured by electromagnetic radiation, and "electromagnetic poisoning" occurs. The degree of electromagnetic radiation damage to human body is related to the following factors: (1) the intensity of electromagnetic field. The higher the intensity of the electromagnetic field around the body, the more energy the human body absorbs, the more heavy the damage is. The greater the power of the radiation source, the closer the source of the radiation, the higher the intensity of the electromagnetic field and the heavier the human body. The frequency of electromagnetic radiation. The higher the frequency of electromagnetic radiation, the more obvious the heat effect of the body, the more serious the harm to the human body. Under the interaction, the damage of the pulse wave to the human body is more serious than that of the continuous wave. (3) the electromagnetic wave enters the body depth. The more the electromagnetic wave enters the body, the more harm to people, the depth of electromagnetic wave into the body is related to many factors, such as the wave band of the electromagnetic wave, the form of current, the angle of the electromagnetic wave entering the body (incident angle), the organization of water and tissue, the dielectric constant and the electrical conductivity of the tissue. (4) exposure time. The electromagnetic field has a cumulative effect on the human body. Therefore, the longer the body receives radiation, the shorter the interval, the greater the injury. The surrounding environment. When the ambient temperature is too high, it is not conducive to the human body emitting heat energy transformed by electromagnetic energy, causing the body temperature to increase and electromagnetic field injury to aggravate. 6. Individual differences. The degree of electromagnetic field damage to the human body varies from individual to individual. Generally speaking, in the same situation, women are more serious than men, children are more serious than adults, and thinner people are heavier than obese ones, which may be related to the water content of human body.
4 protective measures for electromagnetic radiation
To prevent or reduce electromagnetic radiation damage, the fundamental starting point is to eliminate or weaken the magnetic field strength of the body. Its main measures include shielding and absorption.
Shielding is a technical measure to restrict electromagnetic energy to the prescribed space and to spread to the protected area according to the skin effect of electromagnetic waves. It is to use certain technical means to limit the effect and influence of electromagnetic radiation in a certain space to prevent its spread and diffusion. It usually uses a shell of plate like, flaky or reticulate metal to shield. The silver fabric of our company is one of them, because of its excellent conductivity and common use. The fabric has no softness of two and can be widely used in electromagnetic shielding of clothing, decoration and other fields. In addition, it can also use reflection and absorption to reduce leakage of radiation sources to enhance protection. The radiation intensity in the environment is inversely proportional to the distance to the radiation source, and the power density is inversely proportional to the distance Ping Fangcheng. Therefore, as long as we leave a certain distance from the radiation source, we can obviously reduce the radiation.
Absorption refers to the use of the resonance characteristics of certain materials to absorb the electromagnetic radiation energy to reduce the intensity of the electromagnetic radiation by the impedance matching of the material and free space to absorb the energy of the radiation, and more used in the debugging of the microwave equipment. It requires that the radiation energy can be greatly attenuated near the source, so as to prevent pollution to the larger space. At the same time, power absorber and equivalent antenna can be used in the main radiation direction. In addition, the shielding material and the absorbing material are superimposed to make the protective plate or protective cover, which can not only prevent the directional propagation of electromagnetic radiation, but also can be absorbed to avoid two times of pollution, and can also greatly reduce the energy of electromagnetic radiation, and play a good protective role.
In addition, in order to reduce the scope of electromagnetic radiation pollution, effective prevention measures should be taken to different types of radiant sources according to specific conditions, so that the amount of leakage is reduced to the maximum and the purpose of eliminating pollution is achieved. As household appliances and mobile communications in order to reduce the pollution of electromagnetic radiation, the following measures are proposed to take precautions: (1) do not put too much concentration of household appliances, especially electric appliances with large power, high frequency, and easy to produce electromagnetic waves, one is to prevent interference from each other, and two is not to be a radiation concentration, especially some Household appliances that produce electromagnetic waves should not be put in the bedroom so as to avoid exposing themselves to the danger of over dose radiation. All kinds of household appliances, office equipment, mobile phone and so on should try to avoid long time operation and simultaneous operation, and should buy green electrical appliances which use less electromagnetic radiation. Attention should be paid to the distance between the body and the office and household appliances, the farther away from the electrical appliances, the smaller the electromagnetic waves will be infringed upon. 4. When placing a microwave oven, the height should be below the head of the human body to prevent brain and eye damage. In the process of use, it should be as far as possible. As far as the electromagnetic radiation area is as far as possible, if the housing is near the high radiation area, it is possible to monitor the electrical apparatus centrally, and keep it within the safety environment index. Conditional protection measures may be adopted, such as radiation protection clothing, radiation proof aprons, etc. Eat more carrots, spinach and other foods rich in vitamin A, vitamin C and protein, and drink green tea regularly. In addition to the consumption of ginseng, Schisandra, royal jelly, wolfberry and other drugs, in order to regulate the state of the body's electromagnetic field disorder, strengthen the ability of the body to resist electromagnetic radiation, and improve the ability to restore organs and tissues.
5 Conclusion
Human beings live in a huge electromagnetic field, electromagnetic radiation is ubiquitous, but not all cases are injured by electromagnetic radiation. The harm of electromagnetic radiation is not as terrible as people think, only when the electromagnetic radiation exceeds a certain value, it will have a bad effect on the human body. The relevant units should pay attention to this, strengthen publicity and education and management, let the masses understand the basic principles of electromagnetic radiation, grasp the key points of protection, and take necessary protective measures to protect people from the harm caused by electromagnetic radiation as much as possible.