What is the intensity of ultraviolet light related to?

The intensity of ultraviolet rays is mainly related to the thickness of the ozone layer.

Other related factors: the height of the sun, altitude, weather and other factors, as well as the thickness of the ozone layer (ozone can absorb most ultraviolet rays) and the reflection of ultraviolet rays by other atmospheric components (such as carbon dioxide). The main factor is the thickness of the ozone layer. Without the ozone layer, human beings can't survive, and long-term exposure to ultraviolet rays will lead to diseases such as skin cancer.

Ultraviolet intensity is divided into five grades:

1 is the weakest, usually indicating rain;

Level 2 is weak and generally cloudy;

Level 3 is medium, generally cloudy, and occasionally a little sun can be seen from the clouds;

Level 4 is strong, generally sunny;

Level 5 is the strongest, usually showing particularly sunny weather.

April-September is the season with the strongest ultraviolet radiation; 10 is the strongest period of ultraviolet radiation from morning to 2 pm; Noon is the peak of ultraviolet radiation.

Subtitle answer: ultraviolet rays are related to the intensity of sunlight, but they will be much weaker at night. Ultraviolet rays have the most obvious effects on human skin and eyes. The absorption of ultraviolet rays by skin is related to its wavelength. The shorter the wavelength, the smaller the depth of penetration into the skin and the weaker the pigmentation after irradiation; The longer the wavelength, the deeper the penetration into the skin and the stronger the pigmentation after irradiation.

Some materials used in general industrial or high-tech fields have very high performance and are very beneficial to the environment, but their adhesion and printability are generally poor. The short wavelength ultraviolet (UV) surface cleaning and surface modification technology provided by the company can obtain extremely clean surface and strong surface adhesion after treating the above materials with clean high-energy UV light source.

The basic reaction of modification is the oxidation reaction caused by ultraviolet light. After ultraviolet irradiation on the solid surface, the pollutants on the surface are oxidized, then decomposed into volatile substances such as CO2 and H2O, and finally volatilized and disappeared. And the surface forms a favorable side, followed by such as? Hydrophilic groups, such as OH, COO, CO, COOH, etc. The adhesion of the modified surface is greatly improved.

The progress of ultraviolet light source technology ensures that UV/O3? Surface modification technology gives full play to its outstanding advantages. UV/O3？ Surface modification technology is more and more widely used in solid surface treatment because it can obtain high cleanliness and surface adhesion.

Extended data:

Ultraviolet light is located outside purple light in the spectrum and is invisible light. It can make many substances excite fluorescence, and it is easy to make photographic negatives sensitive. When ultraviolet rays irradiate the human body, it can promote the synthesis of vitamin D and prevent rickets. It is a fact that children often bask in the sun. Ultraviolet rays also have bactericidal effect, and the wards of hospitals are all disinfected with ultraviolet rays.

However, too strong ultraviolet rays will do harm to the human body, so we should do a good job of protection. Glass, oxygen in the atmosphere and ozone layer in the sky all have a strong absorption effect on ultraviolet rays, which can absorb most of the ultraviolet rays in the sun, so it can protect the creatures on earth from ultraviolet rays.

In order to resist ultraviolet rays, organisms produce pigments to absorb ultraviolet rays, thus protecting organisms from ultraviolet rays.

Ultraviolet light is generated by the excitation of electrons in the outer layer of atoms. The main ultraviolet light source in nature is the sun. When sunlight passes through the atmosphere, ultraviolet rays with wavelength less than 290nm are absorbed by ozone in the atmosphere.

The artificial ultraviolet light source has arcs of various gases (such as low-pressure mercury arc and high-pressure mercury arc), and ultraviolet light can make the photographic film sensitive chemically, which has a strong fluorescence effect. Fluorescent lamps, all kinds of fluorescent lamps and black lights used to trap and kill pests in agriculture, all use ultraviolet rays to excite fluorescent substances to emit light.

Ultraviolet rays can also prevent counterfeiting and have physiological functions such as sterilization, disinfection, and treatment of dermatosis and rickets. Ultraviolet rays have strong particle properties and can produce photoelectric effects on various metals.

References:

Baidu encyclopedia-ultraviolet