Still blowing the air conditioner?Come in to learn about the heat of physics!

Probably like each student was said to be the worst,

There are a few days in the summer of each year,

It makes people believe that this is the hottest summer.

I was looking forward to school every day before,

Now I look forward to cooling every day.

Today is the beginning of autumn,

The number on the thermometer seems to be talking,

After school, stay after school,

Don't want to say goodbye to the heat after entering the autumn.

Although the air conditioner is good, although it works well,

But too ordinary,

There is no technical content,

We cannot reflect our extensive physical knowledge.

it's here,

Xiaobian has three forms that belong to physics

Summer exclusive handsome (bing) gas (bing) method of cooling the summer.

Make sure you become the most beautiful one on the street.

State in advance,

The method in the text is pure brain hole,

Do not imitate it easily.

The first style of the summer heat -the heavenly people separate

The first style of the summer heat is separated, separating people from this hot day, eliminating the troubles of the heat.

There are three types of heat transfer methods: heat conduction, heat convection, and heat radiation.

Hot conduction | Source: Bilibili

How is the calories transmitted to human body?

Take the editor who just came out of the air -conditioned room as an example. The temperature of the editor's body is relatively low than the air. The hot air and cold human body close to Xiaobian's body first occur. The air -forming heat flow is formed, so that the heat air in the distance is close to the human body and continues to occur with the human body. In this cycle, the heat is transmitted to the human body, and the human body will feel hot.

This trick is "separated by heaven and man", which is to isolate this heat transfer process with thermal insulation material, so that the heat of the outside world cannot be passed on to the human body.

The insulation materials recommended by Xiaobian are almost all the insulation artifacts of the northern households -cotton coat.

In winter, warmth is kept warm. In the summer, it is well -loved by the people, although it does not look so tall, but it is well -loved by the people.

The thermal insulation function of cotton clothes can not only keep warm, but also "cold". The cotton in the cotton coat supports the porous structure. The porous structure can fix a part of the air to block the heat of the air from the distant air. transfer.

Those who have experienced cotton in the summer may be questioned: Xiaobian, I wore cotton clothes in summer, it is even more hot?

It is yes, although the calories outside cannot get in, but the calories produced by themselves can't get out.

Therefore, we also need to put ice cubes in the cotton coat, absorb the calories emitted by the human body with ice, and keep it cool.

Although the ice cubes are cool, but a little bad is easy to melt, and it will wet clothes after turning.

There is a better alternative: ice cream, the refrigeration effect is not bad, the built -in packaging will not leak out of the clothes, and it is really clean and hygienic to stuff in cotton clothes to cool down.

Type of the Second Summer -Tianren Unitlin

What is "unity of heaven and man"?

The "unity of heaven and man" refers to the bravery to face the challenge, face the heat of the heat, accept the exposure in the sun, and turn itself into a part of this influential summer day, and realize the comprehensive sublimation of spiritual and meat and body temperature. As long as I am the hottest, all environments can make me feel cool.

Maybe you will have doubts, but don't worry, listen to the editor to give you a detailed analysis.

On the one hand, hot and cold is a subjective and relative concept. Xiaobian's air conditioner is about 25 ° C, but Xiaobian's mother feels cold at 28 ° C; although the temperature of the ice house of the Newt people is only 0 ° C, it is very warm in the environment of minus 40 ° C. When the sun is very hot in the sun, when I return home or cool, although the temperature is still high, it still feels cool. This is very natural, and it is by no means stupid.

On the other hand, we analyze from heat dissipation.

The human body's heat dissipation method can be roughly divided into three types: radiation heat dissipation, conduction and flow heat dissipation and evaporation heat dissipation. The first type of "Tianren Two" is to solve the problem of hot summer heat from the perspective of conduction and convection. This type of "heaven and man unite" uses radiation heat dissipation.

Anyly higher than the absolute zero item will generate heat radiation, and radiate energy in the form of electromagnetic waves. Thermal radiation is generally related to the nature of the object itself; ideally, there is a special object that can completely absorb external radiation without reflection. It is called black body. Black body radiation is only related to the temperature of the black body, which has nothing to do with other nature of its own nature. , Commonly used in heat radiation research.

When the human body perform radiation heat dissipation, radiation heat dissipation is related to the temperature difference between the skin and the environment and the effective radiation area of ​​the body. The larger the temperature difference between the skin and the surrounding environment, the more radiation is the more. The larger the effective radiation area of ​​the body, the more radiation from the radiation.

After the sun exposure, the temperature of the human body has increased, radiation heat dissipation is increased, and the heat dissipation can be increased to feel cool. This is the principle behind "the unity of heaven and man".

Of course, this method is only recommended to try at noon, because there will be an accident in the morning and evening.

Very easy to use.

The third style of the summer heat -big laser

What? Can't you get you on both?

Then you can only sacrifice the trick of the bottom of the box -big laser!

The above two forms are the application of the heat transfer method, and this trick directly points to the origin of the Avenue, and solve the problem directly from the essence of "heat".

In the high school physics class, the essence of heat is the micro -particle movement that constitutes the substance. The more severe the movement of the micro particles, the higher the temperature and the hotter the object. Therefore, as long as we do the opposite and find a way to weaken the movement of micro -particles, the temperature can be reduced. The method of weakening micro -particle movement has already been proposed, that is, laser refrigeration.

There are two main principles of laser refrigeration, Doppler effects and anti -Stocks fluorescent effects. The performance of the two is similar, both through the scattering process to reduce the energy atomic energy and reduce the intensity of the material atom movement.

The thin atomic gas generally uses the Doppler laser refrigeration technology, and the laser irradiation atomic gas with a slightly lower frequency than the atomic absorption frequency is used. Among them, there will be atoms that move in the direction of the laser. Due to the Doppler effect, the frequency of photons will rise. High, it can be absorbed by the atom; the direction of the momentum of the photon and the atom is the opposite, so the speed of the atom after absorbing the photon will be reduced. Laser in different directions in different directions can achieve constant deceleration of atoms.

Doppler laser refrigeration. 1 Atomic restlessness, the frequency of the laser is slightly lower than the absorption frequency, and has no effect; 2 atoms and laser are motion. In the atomic perspective, the laser frequency decreases and red moves; 3.1-3.3 atom and laser movement, in the atom It seems that the frequency of laser increases, blue shifts, and can absorb photons in specific conditions, and then release photons in any direction and slow down. | Picture Source: Zhihu@| | |

Through the Doppler refrigeration technology, the temperature of the atom can be cooled to the absolute zero -by one millionth, which is the only way for humans to approach absolute zero.

The anti -Stock fluorescent cooling method is an emerging laser refrigeration technology. In short, it uses laser to induce substances to release fluorescence to reduce the micro particles that constitute the substance to lower energy levels.

The material atoms are in the separate energy level. When the laser with a specific wavelength is used to illuminate the substance, the atom will absorb the photon, jump from the initial state (non -base state) to the high energy stimulus, and then move to the base state and release the photon. The energy of the photon is greater than the energy of absorbing the photon. Therefore, after the anti -Stocks fluorescence process, the atomic energy decreases, the movement weakens, and the temperature of the material decreases.

The energy-level schematic diagram of Stocks fluorescence (left) and anti-Stocks fluorescence process (right)

Back to the summer, the "big laser" uses laser to illuminate the human body and directly cools down the human body from the atomic level. Compared with other surface cooling methods, "big laser" can be described as a decrease in dimension. Human experience the feeling of "cooling the heart".

Laser refrigeration technology has no vibration, no noise, non -electromagnetic radiation, small volume, light equipment weight, high reliability, long life, and the refrigeration interval is the most widely refrigerated method (can be close to absolute zero). In addition, it is the perfect way to cool down the summer heat.

The so -called: "Eliminate your own summer, let others say!"

Facing hot,

The temperature is ice, the posture is handsome,

Don’t be limited by worldly eyes, you can restrict your creativity,

Courage to let go of yourself,

You can also spend this summer as handsome as Xiaobian.

What are the exclusive methods of summer friends?

Welcome to share in the message area ~

Reference

[1] Luo Zhizhi. Research on the influence of indoor air flow rate on human physiological indicators and thermal comfort [D]. Chongqing University, 2005.

[2] Li Wenjing. The human body heat feeling in different heat environments [D]. Hunan University, 2006.

[3] Feng Congress, Liang Ruobing, Ning Jingyu, Gao Yan, Guo Zhenhong. Analysis of the effects of solar radiation on the heat comfort of the human body [J].

[4] Chen Jun, Tian Fang, Mondei, Jia Xu, Gao, Wang Ming, Li Na, Li Lisha, Ni Shifeng. New refrigeration technology research progress [J]. Ningxia Agricultural Forestry Technology, 2011,52 (06): 67-70 Then, then, then

[5] Research progress and review of Qin Weiping's anti-Stocks fluorescent refrigeration [J]. Physics progress, 2000 (02): 93-167.

[6] Shen Chao, Zhang Jun. The research status and future of laser refrigeration solid materials [J]. New material industry, 2016 (01): 57-60.

Edit: Lezi Superman

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