Infrared rays are a kind of light invisible to the human eye, and in the last 20 to 30 years, infrared technology, which has been in its infancy, has been widely used in various fields. Began to apply to the production, and formed a new technology - infrared technology.
In 1800, the British scientist Heschel did an experiment, he divided the sunlight into colored bands of light after the thermometer to measure the temperature of various light, found a strange phenomenon: close to the sun's deep red light outside of the invisible part of the temperature is even higher than the red light. This is an unexpected discovery. Because before only know the sunlight has seven colors, as for the seven colors outside the darkness of what substances exist, is not clear. So, Heschel envisioned in the sun's radiation, in addition to visible light, must also contain a human eye invisible radiation. Later, after the experiment proved: this radiation also exists in other objects issued by the radiation. At that time, people called it "invisible radiation". Because of this "invisible radiation" is found outside the red light, so later called it infrared radiation, also called it infrared.
In 1887, infrared light was successfully produced in the laboratory, which made people realize that visible light, infrared light, and radio waves are essentially the same. To the 20th century, due to the needs of production practice, to promote the development of various new technologies, infrared science also came out of the laboratory, began to apply to production, and formed a new technology - infrared technology.
The last two or three decades, the first emergence of infrared technology, in various fields has been widely used.
Infrared light has a greater thermal effect than red light, penetrating ability is also very strong, with it to dry things both fast and good. So people often use it to dry the paint of airplanes, ships and cars. In the past, natural drying often make the surface of the paint to form a hard shell, inside the moisture can not be emitted, the formation of a bubble, affecting the quality of paint. The use of infrared drying paint, there is no such disadvantage. Infrared penetration is so strong that it can be used to dye synthetic fiber fabrics. For example, after infrared heat penetrates into the nylon fabric, it will make the structure of the nylon fabric change, making it easy for the pigment to get into the fiber, fix the pigment on the fabric, and dry it. In this way, people can use infrared light to dye the nylon fabric into a variety of bright colors.
Infrared light is a kind of light invisible to the human eye, which can be used to form an invisible line of defense. In order to do a good job of protection of the warehouse, you can use reflectors, infrared rays cleverly around the warehouse around a circle, and then projected to a can only feel the infrared radiation photoelectric tube, so that the photoelectric tube to emit current. The reflector, photoelectric tube, etc. well hidden, composed of an imperceptible line of defense. If someone dares to warehouse infringement, it will cover up the infrared ray, infrared ray once was covered up photoelectric tube stops working, connected to the photoelectric tube on the body of a switch immediately shut down, the alarm bell will ring.
Not long ago, scientists developed a successful instrument called pyroelectric camera, also known as infrared TV. It can be used to detect the source of fire, check fire hazards, fire monitoring, and can issue timely warnings, known as the "fire sentinel". Due to infrared TV camera, is relying on the infrared rays emitted by the subject to camera, the higher the temperature of the subject, the stronger the infrared rays emitted, the clearer the image will be shot. Therefore, infrared TV can not be subject to smoke, clouds and wind and rain and other obstacles, very sensitive to all kinds of fire check, put out the fire in the time of the just outcropping.
Infrared TV camera, and then configure the fire identifier, automatic tracking system, search institutions and binoculars, it constitutes a new type of urban fire automatic monitoring system. It can automatically search and find five, six kilometers away from 2 ~ 3 square meters then the size of the fire, and can automatically track and alarm. In this way, it can realize the fire command and dispatch automation, for timely detection of fire, fire, provides a modern technical means.
Infrared TV, also used in industry for darkroom operation monitoring, non-invasive, thermal exploration of natural resources; in agriculture for the detection of forests, pastures, fire; transportation for fog permeable navigation and so on.
Infrared TV or a "luminous eye" it! It can be in a dark situation, the enemy's positions, military facilities for effective reconnaissance, even if the enemy hidden very clever latent post, but also can not escape from its sharp eyes; can also be used in border posts, a particular area to monitor; can also be "through" through the snow, "to see" to see the "infrared" television. "See" the enemy hiding under the snow. There is also an infrared microscope. A mention of the microscope, people tend to think that this is a kind of instrument used to magnify small objects. In fact, it is an instrument used to measure temperature. However, it is different from the general temperature measuring instrument, can be used to measure the temperature of a very small point. Tiny point of temperature, although you can also use the semiconductor thermometer to measure, but because it is measured in direct contact with the surface of the object, it is easy to affect the measured point of the physicochemical properties; if you use the infrared microscope to measure, not only to overcome these shortcomings, but also more accurate than the semiconductor thermometer.
Infrared technology, although the first glimpse, but we are convinced that, along with the continuous development of science and technology, it will make us a lot of can be expected and even unexpected wonderful things.
Infrared light is also known as "infrared light". In the electromagnetic spectrum, the wavelength between red light and microwave electromagnetic radiation. Outside the range of visible light, the wavelength is longer than red light, there is a significant thermal effect, you can use the temperature difference between the electric coupling, photoresistor and other instruments to measure the wavelength of 0.77 ~ 3 microns for the near infrared region; 3 ~ 30 microns for the mid-infrared region; 30 ~ 1,000 microns for the far-infrared region. Infrared rays are easily absorbed by the object, converted into the object's internal energy; through the clouds and other substances filled with suspended particles, it is not easy to scatter, has a strong penetrating ability, infrared applications are very wide, can be used to bake food, drying paint and medical treatment. Substance absorption spectrum of infrared light on the study of the molecular structure of substances, chemical analysis and control of the chemical industry is of great significance. Infrared detectors are commonly used in the military to detect targets, as well as infrared communications.
Infrared television using the scene itself to be photographed thermal radiation or reflected infrared radiation to film camera and display system called infrared television. Suitable for non-contact and non-destructive inspection, often used in industry, medicine, space development, military and so on.
Infrared visible red end and microwave electromagnetic waves between the wavelength range of about 7 × 10?7 m ~ 1 × 10?m. In 1800, the British physicist Sheikh Earl will be placed on a thermometer in the daylight spectrum of the outside of the red region, and found that there is still a very strong thermal effect. So the invisible rays called infrared rays. All objects are radiating infrared rays outward. The higher the temperature of the object, the wider the band of infrared rays emitted. The mechanism of infrared radiation is the excitation of the outer electrons of an atom. The most notable feature of infrared radiation is its thermal effect, the wavelength of infrared light is longer than red light, so the diffraction phenomenon is more significant, easy to pass through the clouds of smoke is not easy to be absorbed by the suspended particles in the air.
The use of infrared heat to heat objects, such as drying paint and grain and medical treatment, etc., the use of infrared-sensitive film can be long-distance photography and high-altitude photography, from satellites with infrared light on the ground photography can be clearly seen on the ground and the object and not subject to the limitations of day and night. As all objects are constantly radiating infrared radiation, and different objects radiate infrared wavelength and intensity of different, so the application of infrared remote sensing technology can be in the aircraft or satellite survey geothermal search for water, weather forecasting. In modern warfare, the use of infrared night vision devices such as night vision equipment to make the other side of the target at all times. With infrared physics can detect the infrared radiation of high temperature objects. Now infrared sensors are also used as anti-missile early warning.
The use of thermometers to solve the optical problem - the discovery of infrared
The sun is the most familiar to mankind but the universe of celestial bodies, it rises every day in the east and falls in the west, morning and evening, and do not spare the sunshine to the earth, so that all things can grow and reproduce. In summer, the red sunlight makes people feel hot and difficult, if the winter, people and try to get as much sunshine, in order to use the sun's heat to ward off the cold. Since ancient times, human beings have known that the sun brings light and heat to people, and that the sun's light and heat can never be separated. But in generously accepting the light and heat from the sun, mankind has never considered how light carries heat.
The color of the sun with the development of science, to the 17th century, people began to systematically study the phenomenon of light. 1666, the great scientist Isaac Newton in the let the sunlight through the glass prism of the experiment found that the white sunlight is surprisingly by the red, orange, yellow, green, blue, indigo, violet monochromatic seven colors of light, which is the famous physics of the "dispersion of light experiment". Newton's contributions to the study of optics are many, and his research achievements in the linear propagation of light, the refraction and reflection of light, the imaging of lenses, the theory of color, and many other aspects have become the most important part of the treasury of human knowledge. But Newton himself, as well as his contemporaries scientists are focused on the thousands of various optical phenomena or in the endless debate on the nature of light, but no one cares about the light of the sun. It may be said that for a long time in the history of optics the light of the sun was the pariah of science.
Pastor's InspirationIn 1738, a child named Herschel was born in England. Herschel was an ordinary child as a child and did not grow up to be a scientist. He was a clergyman by profession, but was uniquely attracted to sunlight. For this reason, he bought a large glass prism on his desk, from time to time to appreciate the sunlight through the formation of the seven-color band. 1800 one morning, the age of Hirschauer looked at the beautiful band of colors, suddenly like a child curious to ask himself: "Sunlight with heat, but the composition of the sunlight of the seven monochromatic light, which one of the band with the most heat? " His seemingly simple question was unknown to anyone at the time, and so Hirschauer began to think about it, trying to find the right answer.
A few days later, Hirschauer found a solution to this problem. He thought, the sunlight through the prism into seven monochromatic light, if we know the temperature of each kind of light, do not know who among them carries more heat? Then, Hirschauer in his room on the wall of a white paper as a light screen, and let through the prism of the seven-color light bands shining on the paper screen. Then Hirschauer hung a thermometer in the place of each band of light. Fearing that his observations were not comprehensive enough, he hung another thermometer outside each of the red and violet bands of light.
After this was done, Hershel recorded the readings that each thermometer began to take, and then sat down in a chair at the table and began to observe. The thermometer's mercury column rose slowly as Hershel waited patiently. After about half an hour, the readings of all the thermometers stopped changing. Hirschauer noticed that the temperature in the green zone had risen by 3°C, the temperature in the violet zone had risen by 2°C, and the reading of the thermometer outside the violet zone was almost unchanged. To his surprise, however, the reading of the thermometer outside the red-light zone had risen by 7 degrees Celsius.
Herschel, though a priest, had the makings of a scientist. Immediately after he discovered this peculiar phenomenon, he repeated the experiment. But the results of the experiment were the same many times: the thermometer outside the red light zone showed the greatest rise in reading. After a detailed analysis, Herschel concluded that the spectrum of sunlight is actually wider than the seven monochromatic colors of light seen by people, and that there must be some kind of invisible light outside the red band, and that this light carries the most heat. The scientific community later named this invisible light infrared, and Herschel's discovery of it has gone down in scientific history.
Infrared light from where in the Herschel discovered infrared, because at that time mankind for many natural phenomena is not deep enough to understand, and at that time the overall level of scientific research is not high, so engaged in infrared research scientists are not many. Later, with the development of physics and other scientific disciplines, it is clear that infrared and other visible light, are part of electromagnetic waves. Only visible light wavelength range of 0.4-0.75 microns, while the infrared wavelength range of 0.76 - 1000 microns, so the human eye can not see.
Scientists later also know the mechanism of infrared radiation, infrared radiation, infrared radiation, any object as long as the temperature is higher than the absolute temperature of zero - 273 ℃, their molecules have thermal movement, accompanied by the thermal movement of such molecules objects radiate infrared radiation with varying wavelengths to the outside.
The wonderful use of infrared human discovery of infrared history is very long, but until this century with the rise of radio electronics, materials science and development, infrared has become a hundred times the value of high-tech identity in front of us.
We all like to watch CCTV by Zhao Zhongxiang hosted the "Animal World" program, which so many animals at night is the use of infrared photography to get the footage. As any object radiates infrared radiation, scientists have developed a special record of infrared signals can be infrared film. This film is mounted on an ordinary video camera, and then borrow other devices can be at night and away from the animals in the place to shoot. Crocodiles are familiar to mankind a fierce animal, in order to study the habits of crocodiles and their child-rearing process, researchers in the appropriate season to the automatic infrared camera placed near the crocodile's nest. From the footage captured, it can be seen that when the baby crocodiles are just hatched, the mother crocodiles sometimes lick them, sometimes move them, and sometimes feed them with food. The ferocity that we usually see is gone, and her compassion for her children is no less than that of us humans.
Thermal infrared detection system is an important application of infrared. As any one of the objects radiating infrared radiation are different from other objects around the heat source, that is, an object with the surrounding environment has a temperature difference, thermal infrared detection system is through the detection of the temperature difference and the discovery of the target. For example, the military use this device to find the enemy hidden in the bushes and the enemy is traveling vehicles, tanks and so on. In the movie or television often see such a battle scene, two planes chasing each other in the air, suddenly behind the plane shot a missile, and the other see this immediately and constantly change the direction of flight, a moment to turn, a moment up and down roll, but a few seconds later was still hit by the missile. Why can't the airplane get rid of the missile? This is because the exhaust pipe of the engine of a flying airplane is a source of infrared radiation, and a missile equipped with an infrared detector will find it without difficulty. Although the airplane tries hard to get rid of the missile, the electronic navigation system on the missile makes the missile always bite the heat source, so that the airplane whose speed is lower than that of the missile can not be hit.
Today, the infrared range of application is more and more extensive, in industry, agriculture, military, food processing and security work and many other aspects are extremely important applications. But don't forget that the discovery of infrared light was one of the least invested and simplest discoveries in science - relying only on a glass prism and a few thermometers.
Infrared in the electromagnetic spectrum, the wavelength between red light and microwave electromagnetic waves. Wavelength of about 0.75 ~ 1000 microns, can not cause visual. Infrared has a significant thermal effect, can be detected with a temperature-differential coupling, photoresistor or photocell and other instruments. Infrared is easy to be absorbed by the object, converted into its internal energy; in through the clouds and other substances filled with suspended particles, there is a strong penetration ability. Infrared in the military can be used for communication and tracking, detection of targets; in industry can be used to dry paint, baked food, etc., for long-distance targets, high-speed movement of the target can be non-contact temperature measurement with infrared technology; in medicine can be used in infrared technology to diagnose diseases. Infrared technology in the last 20 years has become a rapidly developing emerging technologies.
[Infrared] invisible to the human eye, but can pass through or penetrate into many substances, such as thin wood, glue wood, trees, paper, mist, leather and so on. Substance is too thick, infrared rays can not pass through, can only penetrate to a certain extent. Infrared light can also deal with atoms, making some changes in the state of motion of atoms. Infrared light has a thermal effect. It was discovered in 1800 by the British astronomer Herschel's discovery is because it has a significant thermal effect. Using the invisible, penetrating, thermal effect of infrared rays, as well as the ability to deal with atoms and other properties, we can find many uses for us. Such as infrared spectral analysis, drying, infrared photography, detection, communication and so on.
Infrared WavesInfrared waves have a wavelength a little longer than the wavelength of visible light that we can see, and most heat waves are infrared waves, which is why when you put your hand on a friend's cheek, you can feel the warmth, but you can't see the light waves.
What is infrared In 1800, scientist Sir William Herschel discovered that the sun's energy in sunlight was a very small amount. In 1800, the scientist Sir William Herschel discovered that about two-thirds of the energy in sunlight comes from heat, or infrared radiation, which is invisible to the naked eye. Objects in the sun will heat up, not because they absorb the visible sunlight we see, but accompanied by infrared radiation energy in the visible sunlight. All sources of heat contain infrared light, and an astronomer can even discover certain planets by means of infrared light, rather than by means of visible light waves. This laser jukebox is activated by infrared light inside the shaker, and a red indicator on the machine lets you know that infrared light is operating. In this detector or sensor box, its sensing power is derived from a motorized photoreceptor that detects light waves. The sensor activates the infrared detector when it is dimly lit; it does not activate during the day when there is no need for illumination.
Infrared receptor infrared receptor is located in the pit viper family (Crotalidae), snakes (pit vipers, rice spoons, rattlesnakes) on both sides of the face, only sensitive to infrared special temperature receptors. Vipers detect the infrared rays emitted by each other in the darkness of the night and act as if they have binocular vision. Under the eye sockets are small holes, also known as foramina. At its base there is a membrane similar to the tympanic membrane of the middle ear, and at its back there is also a cavity that communicates with the outside world, which is very similar to the Eustachian tube. In the cytoplasm there are many mitochondria, in the film on the trigeminal nerve fibers are densely packed such as the network into the endings, the outer side of the Schwann's cells surrounded. Once the infrared light reaches this film, that is proportional to the heat potential changes. On the infrared sensory mechanism is not yet very clear, but the sensitivity is very high, can identify 0.002 ℃. There are also venomous snakes (king snakes) that have infrared sensitivity without orifices, but in this case the sensitivity is said to be very poor.
The discovery of ultraviolet lightOne day in 1801, a scientist studying the solar spectrum suddenly wanted to know whether there was any other invisible light after the sun's light had been broken down into seven colors. He happened to have a bottle of silver chloride solution on hand at the time. It was already known that silver chloride decomposes and precipitates silver when heated or exposed to light, and the precipitated silver is black due to small particles. The scientist wanted to use silver chloride to determine the composition of sunlight beyond the seven colors of light. He used a piece of paper with a little silver chloride solution, and put the piece of paper on the white light dispersed by a prism on the outside of the violet light of the seven-color light. After a while, he really did observe on the piece of paper with silver chloride part of the jiao low piece of black, which indicates that the sunlight dispersed by the prism in the violet light on the outside there is an invisible light, the scientist called this light ultraviolet. This scientist is Ritter, December 16, 1776, Ritter was born in Silesia, Germany. As a child, he was poor and did not study for several years, and at the age of 14, he was apprenticed to a pharmacy. During his apprenticeship, Ritter read many books voraciously and learned a lot about chemistry and physics. With hard self-learning, at the age of 20, he entered the University of Jena, and later made a lot of contributions to chemistry and electrophysiology. 1799, he successfully electrolyzed copper from a solution of copper sulfate with a galvanic cell, which led him to the conclusion that electrostatic force is consistent with galvanic force. He also correctly pointed out that the cause of galvanic current was a chemical reaction inside the galvanic cell, thus becoming the first person to correctly explain the cause of galvanic current. 1802, Ritter made the first dry cell battery, and in 1803, he successfully developed the storage battery. Ritter's major contribution to physics was the discovery of ultraviolet light. Ultraviolet light is radiation with a shorter wavelength than violet light, a part of the solar spectrum that is invisible to the naked eye. Strong ultraviolet light irradiation, on the human body, biological are harmful, but the right amount of ultraviolet light can be used to feel the spirit of the spirit, can promote the body's metabolism, ultraviolet light in medicine is also used to sterilize. In addition, according to the ultraviolet light "light-excited light" (ultraviolet light induced material luminescence) phenomenon, but also created a new analytical method, that is, fluorescence analysis, which can not only detect the structure of the material, but also can be clearly found in the human eye is difficult to find the cracks in the machine parts. The discovery of ultraviolet light to mankind has brought the gospel, but its discoverer Ritter but due to poverty, life is poor, is full of longing to climb to the peak of science, but was taken by the lung disease, at the time of death at the age of only 34.
Ultraviolet light is also known as "ultraviolet light". It is electromagnetic radiation located between violet light and roentgen rays (X-rays) in the electromagnetic spectrum. The wavelength is about (4 to 39) × 10-6 centimeters, and it cannot cause vision (i.e., it is outside the range of visible light). Substances through which visible light can pass are strongly absorbed for certain wavelengths of ultraviolet light. For example: glass has a strong absorption of ultraviolet light with a wavelength of less than 35 × 10-4 centimeters; oxygen and ozone in the earth's atmosphere almost entirely absorbs solar radiation, with a wavelength of less than 29 × 10-6 centimeters of ultraviolet light; crystals (i.e., quartz) absorb ultraviolet light with a wavelength of less than 2 × 10-5 centimeters; and ultraviolet light with a wavelength of less than 2 × 10-5 centimeters is strongly absorbed by the air. Therefore the internal part of the spectrometer for observing this ultraviolet band must be pumped into vacuum, and this band is called vacuum ultraviolet, and the spectrometer applicable to this band is called vacuum ultraviolet spectrometer. Mercury lamps and electric arcs with strong ultraviolet radiation between (25 and 39) × 10-6 cm in their light are commonly used sources of ultraviolet light, and ultraviolet light is usually detected with photoelectric elements and photographic emulsions. Ultraviolet spectroscopy is an important means of studying the structure of atoms, and ultraviolet light also has important applications in industry and agriculture. UV is commonly used in biology and medicine to sterilize and disinfect, induce mutations, and treat skin and cartilage diseases.
Global -- UV increases in densely populated areas NASA recently published a survey report shows that there is a trend of increasing UV in densely populated areas around the world. In the last 10 years, the UV increased by up to 10 percent. The researchers used Earth observation satellites to observe the Earth's ozone layer and UV exposure for 13 years, and produced corresponding maps. These observations were supplemented by data from eight ground-based observatories in Canada, New Zealand and the United States. Accordingly, the researchers analyzed the distribution of the increase in ultraviolet radiation due to the reduction of the ozone layer over the latitudes of the Earth. It was found that there was a significant increase in UV exposure in densely populated areas in both the southern and northern hemispheres. The region around 55°S, including Argentina and Chile in South America, showed a 9.9% increase in UV exposure over a 10-year period. In the United Kingdom, Germany, and Russia, there was a 6.8 percent increase near 55 degrees north latitude, and in Japan and the United States, there was a 4 percent increase in areas between 30 degrees and 45 degrees north latitude.
Absorption of ultraviolet light "can hand" - ozone atmosphere - the Earth's gas shell, humans and all living things are living in this shell. There is a layer in the atmosphere is to absorb ultraviolet energy, that is, the ozone layer. Although the content of this layer of material is very small, but it is extremely important to life on Earth. If all the ultraviolet rays radiated by the sun reached the ground unimpeded, then I am afraid that the existing life on earth would have long been gone. Therefore, the ozone layer acts as an impenetrable shield to protect the environment from the sun's ultraviolet rays, which kill animals. The ozone molecule is made up of three oxygen atoms and is chemically very reactive, with a special odor, hence its name. It is located in the stratosphere of the atmosphere, with the greatest concentration in the ozone layer, which is located at an altitude of twenty to thirty kilometers. It is this layer that absorbs most of the ultraviolet light and serves to protect life on earth. Ozone readily reacts with oxides of nitrogen, thus reducing the amount of ozone. Sources of nitrogen oxides include supersonic aircraft emissions, the widespread use of nitrogen fertilizers into the stratosphere, and Freon, which is widely used as a refrigerant and is the most aggressive "killer" of ozone. These "killers" are causing the ozone layer to diminish. Excessive and prolonged exposure to ultraviolet rays can cause a significant reduction in crop yields, damage human health, and cause skin cancer. We should take early measures to protect the ozone layer!
Ultraviolet light at workTurns out, it's Los Angeles' special geographic location, special weather conditions, and intense sunlight exposure that cause this smog. If any of these components were missing, the smog would not be possible. Scientists have found that the smog in Los Angeles is photochemical smog, this smoke is discharged into the atmosphere of nitrogen oxides and hydrocarbons by the sun's ultraviolet rays and produce an irritating light blue smoke, which contains ozone, peroxynitrite and aldehydes and other complex compounds, they are photochemical reactions generated by secondary pollutants. Under specific geographic conditions, when encountering inverse temperature or unfavorable diffusion of meteorological conditions, smog will accumulate and not disperse, resulting in air pollution events, so that the human eye and respiratory tract is irritated or induced a variety of respiratory tract inflammation, endangering human health.
Forecasting ultraviolet radiation: With the development of science and people's needs, weather forecasting has added a new content: UV index, that is, ultraviolet radiation index. The U.S. National Weather Service in the daily weather forecast program, in addition to temperature, humidity, barometric pressure, wind and other items, but also the UV radiation in 58 U.S. cities at the same time to make a forecast.
The Plants That Tolerate UV Exposure BestThere is a type of ultraviolet (UV) light in sunlight that affects almost all living things. Microorganisms, in particular, are killed in ten minutes or so by a certain dose of UV radiation. So hospitals and certain factories, commonly used ultraviolet light for sterilization. Higher plants are no exception. According to scientists, if the intensity of ultraviolet light equivalent to the surface of Mars as a standard, to irradiate a variety of plants, tomatoes, peas, etc., as long as 3-4 hours to die; rye, wheat, corn, etc. irradiation of 60-100 hours to kill the leaves; and southern European black pine irradiation of 635 hours, is still alive. This is the strongest UV tolerance of plants. Scientists estimate that a plant like the southern European black pine can live on Mars for a season. This fact proves that the existence of living things on planets other than Earth, such as Mars, is possible. Ultraviolet wavelength in the visible violet end to the X-rays between the electromagnetic radiation, its wavelength range between 400 ~ 500 nanometers, can not cause people's vision. 1801 German physicist Ritter found that the violet end of the sunlight spectrum in the outer section of the ability to make the photographic negatives containing silver bromide sensitized, and thus discovered the existence of ultraviolet light. The main source of ultraviolet light in nature is the sun. When sunlight passes through the atmosphere, ultraviolet light with a wavelength shorter than 290 x 10?9 meters is absorbed by ozone in the atmosphere. Artificial ultraviolet light source has a variety of gas arc (such as low-pressure mercury arc, high-pressure mercury arc), ultraviolet light has a chemical effect can make the photographic negative sensitization, fluorescence effect is strong, fluorescent lamps, various fluorescent lamps and agriculture used to trap pests of the black light is used to stimulate fluorescent light-emitting substances with ultraviolet light. Ultraviolet light also has physiological effects, can sterilize, disinfect, treat skin diseases and chondropathy. Ultraviolet particles are strong, can make all kinds of metal photoelectric effect. Ultraviolet light is also known as "ultraviolet light". In the electromagnetic spectrum is located in the violet light and roentgen rays (X-rays) between the electromagnetic radiation. It has a wavelength of about (4-39) × 10-6 centimeters, and cannot cause vision (i.e., it is outside the range of visible light). Substances through which visible light can pass are strongly absorbed for certain wavelengths of ultraviolet light. For example: glass has a strong absorption of ultraviolet light with wavelengths less than 35 × 10-4 centimeters; oxygen and ozone in the earth's atmosphere absorb almost all of the solar radiation, with wavelengths less than 29 × 10-6 centimeters of ultraviolet light; crystals (i.e., quartz) absorb ultraviolet light with wavelengths less than 2 × 10-5 centimeters; ultraviolet light with wavelengths less than 2 × 10-5 centimeters is strongly absorbed by the air. Therefore the internal part of the spectrometer for observing this ultraviolet band must be pumped into vacuum, and this band is called vacuum ultraviolet, and the spectrometer applicable to this band is called vacuum ultraviolet spectrometer. Mercury lamps and electric arcs with strong ultraviolet radiation between (25 and 39) × 10-6 cm in their light are commonly used sources of ultraviolet light, and ultraviolet light is usually detected with photoelectric elements and photographic emulsions. Ultraviolet spectroscopy is an important means of studying the structure of atoms, and ultraviolet light also has important applications in industry and agriculture. UV is commonly used in biology and medicine to sterilize and disinfect, induce mutations, and treat skin diseases and chondromalacia.
[Ultraviolet] In the electromagnetic spectrum is located in the violet light and X-rays between the electromagnetic radiation. Also called ultraviolet light. The wavelength is about 0.04 to 0.39 microns and cannot cause vision. The most prominent characteristic of ultraviolet light is that under its irradiation, fluorescence occurs in many substances, and fluorescent lamps for illumination are made by utilizing the fluorescent effect of ultraviolet light. Ultraviolet light has a chemical effect, can make the photo negative sensitization. UV also has physiological effects and is used in health care. UV rays can also pass through the epidermis and cause chemical changes in the internal tissue cells of the body. Prolonged exposure to ultraviolet light will change the color of the skin, blood vessels will dilate, calcium and phosphorus in the blood will increase, red blood cells and blood pigments will also increase. It is also particularly suitable for the treatment of rickets, pediatric infirmity, tuberculosis other than lungs, and certain infectious skin diseases. Sunlight (through the atmosphere after the air absorbed most of the ultraviolet rays) contains ultraviolet rays, although not much, but it is very beneficial to the human body. Long-term living in the city, working indoors, often due to the lack of ultraviolet radiation and physical weakness, pale complexion, especially in the mines or underground staff, should be commonly irradiated by sun lamps or mercury lamps. In addition, ultraviolet light also makes the paint dry, food, drinking water, clothing, utensils, etc., the role of disinfection and sterilization.
Anti-ultraviolet fabrics have been introduced in recent years, the ozone hole caused by atmospheric pollution so that more and more ultraviolet radiation to the surface, skin cancer patients have risen sharply as a result. Can you tolerate your healthy skin to be poisoned? A scientific and technological inventions from Ningxia to bring the gospel to mankind: anti-ultraviolet and release far-infrared fiber fabrics developed successfully in Ningxia, and recently passed the technical appraisal, made of environmentally friendly functional clothing has also been the initial formation of productivity. Tested by the National Academy of Measurement Sciences, such clothing ultraviolet shielding rate of 98.3%, far-infrared emission rate of 90% or more. Health and epidemic prevention department test recognized as "non-toxic, tasteless, non-stimulating, without any side effects" products. The anti-ultraviolet and release far-infrared fabrics applied to clothing, not only solved the technical elements of anti-ultraviolet radiation, but also has a health care function, so that human beings dressed with the addition of a new concept of clothing series has become the oddball.
X-rays and ultraviolet waves outside the line and X-rays (also known as X-rays) are very short wavelengths, they can penetrate solid objects, such as human tissue. A short exposure to these types of rays is not harmful to the body, e.g., a physician can use X-rays to understand a person's physical condition, however, excessive exposure to these rays will be extremely harmful to the body. Causes of sunburn Prolonged direct exposure to the hot sun is tantamount to overexposure to ultraviolet rays, which can lead to sunburn. People who have been exposed to the sun for many years are at risk of being over-exposed to UV rays