A little knowledge about fog

If the air near the ground is cooled to a certain extent under the conditions of sufficient moisture, breeze and stable atmosphere, the moisture in the air will condense into tiny water droplets suspended in the air, which will reduce the visibility of the ground. This weather phenomenon is called fog. Fog is more common in spring from February to April. When the visibility in the atmosphere is lower than 1 km due to the condensation of suspended water vapor, meteorology calls this weather phenomenon fog.

Conditions for fog formation: cooling, humidifying and increasing water vapor content.

Fog types: 1, radiation fog 2, advection fog 3, mixed fog 4, evaporation fog 5 and smoke.

Why is the fog white?

Experiments show that when white light shines on a transparent object, the transmitted light is mainly the same color as the transparent object, and all other colors are absorbed by transparent body. If a transparent object can transmit all colors of light, then the transparent body is colorless, such as ice. But when water turns into fog, many reflecting surfaces are formed. At this time, light can't penetrate, but is reflected, that is to say, all colors of light are reflected, so the fog becomes white.

2. What do you know about smog?

① Fog itself is a relatively normal weather phenomenon, and there is no pollution; Haze is actually a pollutant.

② Fog is composed of water vapor with relatively large particles; Haze is composed of relatively dry particles, and the particles are very small.

③ The fog is white, and the color of haze is generally yellow or brown.

16. Explain with concrete examples and remarks that the common sense about smog written in the article has been scientifically analyzed and demonstrated, thus enhancing the persuasiveness of the article and the credibility of the content.

17.( 1) Quoting experts' words is not to show that each of us can avoid smoggy weather if we have the awareness of energy saving and emission reduction, but to show the importance of everyone's awareness of energy saving and emission reduction in preventing and controlling air pollution.

⑵ The method of enumerating figures is not to show that smog pollution in Beijing, Shanghai, Guangzhou and Xi 'an is serious, but to show that smog pollution does have an impact on human health.

18. When the pollution is serious, sensitive people should try to reduce outdoor activities; Wear a mask to travel in foggy days; Eat more light food; Don't open the window for ventilation to ensure indoor air quality.

3. Little knowledge about the air, the harm of smog weather

How to deal with smog weather? 1 Go out as little as possible: Because there are large and small particles in foggy days, which are seriously harmful to health, particles will stick to the respiratory tract after entering the body, causing bronchitis and pharyngitis. In particular, the elderly and patients with respiratory diseases with relatively weak resistance should reduce their travel or wear masks to protect their health when exercising outdoors. 2 morning exercises should be limited: many people are used to morning exercises, but in fact, time is not very correct for the human body. Because of the air exchange environment in the morning, the air quality is very poor, especially in foggy days, the respiratory tract is vulnerable to * * *, and it is easy to induce respiratory tract and cardiovascular and cerebrovascular diseases during exercise. 3. Do a good job in personal hygiene, wash your face and rinse your mouth when you go out, change clothes when you go out, and remove pollution residues. 4. Pay attention to diet: drink plenty of water to speed up the body's metabolism. We should try our best to avoid the intake of spicy food. For those who like to eat hot pot in winter, try to eat less. C light diet, eat more fresh fruits and vegetables, tremella, pears, persimmons, lilies, radishes, water chestnuts and other lung-moistening foods. The main components of PM2.5 are elemental nitrogen, organic carbon compounds, sulfate and nitrate. Others include elements rich in the earth's crust such as sodium, magnesium, calcium, aluminum and iron. Heavy metal elements such as copper mainly come from human pollution. Although the spontaneous combustion process will also produce PM2.5, the main sources are human emissions, such as coal burning, gasoline and diesel burning, garbage burning, road dust, industrial pollution, forest fires, pollen bacteria and so on. How did the sky smog appear? In fact, large and small particles in the daily air will reduce daily visibility, but compared with coarse particles, fine particle PM2.5 has a stronger ability to reduce visibility. When visibility decreases, we will be blocked, blurred, unclear, etc. And it will also hinder the light irradiation. Harm to human health? Large particles are easily intercepted by the nose, throat and trachea, or excreted by the movement of villi. However, because PM2.5 is a fine particle, once it is inhaled from the respiratory tract, it will deposit in the human alveoli and then dissolve into the blood, causing blood poisoning and easily reaching the depths of the lungs. It will cause damage to the respiratory system and cardiovascular system, such as respiratory tract, cough, dyspnea, exacerbation of asthma attack, arrhythmia, heart disease and so on.

4. Haze knowledge to see the answer

Reference answer: 15. ① Fog itself is a relatively normal weather phenomenon, and there is no pollution; Haze is actually a pollutant.

② Fog is composed of water vapor with relatively large particles; Haze is composed of relatively dry particles, and the particles are very small. ③ The fog is white, and the color of haze is generally yellow or brown.

16. Explain with concrete examples and remarks that the common sense about smog written in the article has been scientifically analyzed and demonstrated, thus enhancing the persuasiveness of the article and the credibility of the content. 17.( 1) Quoting experts' words is not to show that each of us can avoid smoggy weather if we have the awareness of energy saving and emission reduction, but to show the importance of everyone's awareness of energy saving and emission reduction in preventing and controlling air pollution.

⑵ The method of enumerating figures is not to show that smog pollution in Beijing, Shanghai, Guangzhou and Xi 'an is serious, but to show that smog pollution does have an impact on human health. 18. When the pollution is serious, sensitive people should try to reduce outdoor activities; Wear a mask to travel in foggy days; Eat more light food; Don't open the window for ventilation to ensure indoor air quality.

5. Haze knowledge to see the answer

Reference answer:

15.① Fog itself is a relatively normal weather phenomenon and there is no pollution; Haze is actually a pollutant.

② Fog is composed of water vapor with relatively large particles; Haze is composed of relatively dry particles, and the particles are very small.

③ The fog is white, and the color of haze is generally yellow or brown.

16. Explain with concrete examples and remarks that the common sense about smog written in the article has been scientifically analyzed and demonstrated, thus enhancing the persuasiveness of the article and the credibility of the content.

17.( 1) Quoting experts' words is not to show that each of us can avoid smoggy weather if we have the awareness of energy saving and emission reduction, but to show the importance of everyone's awareness of energy saving and emission reduction in preventing and controlling air pollution.

⑵ The method of enumerating figures is not to show that smog pollution in Beijing, Shanghai, Guangzhou and Xi 'an is serious, but to show that smog pollution does have an impact on human health.

18. When the pollution is serious, sensitive people should try to reduce outdoor activities; Wear a mask to travel in foggy days; Eat more light food; Don't open the window for ventilation to ensure indoor air quality.

6. Life Tips: How to prevent the harm caused by smog

1, reduce going out

The elderly, children and people susceptible to respiratory diseases with weak resistance should try to reduce going out or outdoor activities, and wear masks to protect their bodies when going out to prevent pollutants from invading the lungs through the nose and mouth. When you come back from going out, wash your face and skin immediately.

2. Wear a mask and go out less.

Wear a mask when going out, but it is best not to wear it for more than 4 hours. Cloth masks should be cleaned and disinfected with boiling water every day. Some personalized masks and cartoon masks are only one or two layers thick, so it is difficult to filter viruses and dust in the air. Common masks such as N95 and KN90 have a good protective effect on PM2.5, but they are not suitable for children. Disposable masks should not be used repeatedly to avoid secondary pollution.

3. Close the doors and windows to purify the air

Try to close the doors and windows in foggy days, and you can open the window for a short time when there is plenty of sunshine and less pollutants at noon. The installation and use of air purifiers can improve indoor air quality to some extent, and products that do not produce by-products such as ozone should be selected.

Step 4 put green plants indoors

Planting some green plants indoors can absorb carbon dioxide in the air and produce oxygen.

5, pay attention to diet

Patients with chronic respiratory diseases, especially the elderly, should keep scientific life rules, avoid overwork and drink plenty of water. Pay attention to a light diet, eat less sex food, eat more tofu, milk and other foods, and supplement vitamin D when necessary.

6. Be careful when driving and walking.

Moderate and severe haze weather, low visibility and poor line of sight. People who drive, ride and walk should be more careful, especially when passing through intersections and unguarded railway crossings, to slow down and obey traffic rules to avoid traffic accidents.

8, timely treatment of disease recurrence.

Patients with chronic respiratory diseases, such as asthma, chronic pharyngolaryngitis, allergic rhinitis, cardiovascular diseases or the infirm, the elderly, children, pregnant women, etc. , should avoid going out. If you need to go out, especially patients with asthma and coronary heart disease, you should take medicine with you to avoid aggravation.

7. A little knowledge about air

The gases that make up the atmosphere around the earth. Colorless and odorless, the main components are nitrogen and oxygen, and a very small amount of inert gases such as radon, helium, neon, argon, krypton and xenon, and water vapor, carbon dioxide and dust.

At 0℃ and standard atmospheric pressure (1.013 *105pa), the air density is1.293g/l.

Air at room temperature is colorless and odorless gas, while liquid air is light yellow liquid, which is easy to flow. Generally, when air is liquefied, carbon dioxide has been removed, so the components of liquid air are 20.95% oxygen, 78. 12% nitrogen and 0.93% argon, and other components are few, which can be omitted. As a mixed gas, when it condenses at constant pressure, the temperature decreases continuously. For example, at standard atmospheric pressure (10 1.3KPa), air begins to condense at 8 1.7K (dew point), and when the temperature drops to 78.9K (bubble point), it is completely transformed into a saturated liquid. This is because the high-boiling components (oxygen and argon) condense more at the beginning, while the low-boiling components (oxygen) condense more at the end of the process.

In ancient times, air was once considered as a simple substance. 1669, You Mei inferred that the composition of air was very complicated according to the experiment of candle burning. About 1700, Starr of Germany put forward a general chemical theory, namely "phlogiston theory". He believes that there is an invisible so-called phlogiston, which exists in combustible substances. For example, when a candle burns, phlogiston escapes, and the candle shrinks and collapses into ashes. He believes that burning loses phlogiston, that is, candle-phlogiston = ashes. However, phlogiston theory cannot explain some phenomena in natural changes after all, and there are serious contradictions. The first is that no one has ever seen phlogiston; Incredibly, the mass of the second metal increases after combustion, so "phlogiston" must be negative. 1774, French chemist lavoisier put forward the theory of combustion oxidation, which denied the phlogiston theory. When lavoisier was doing the combustion experiments of metals such as lead and mercury, he found that some metals turned into colored powder, and the volume of air in the bell jar decreased by 65,438+0.5 of the original volume. The remaining air could not support the combustion, and animals would suffocate in it. He called the remaining 4/5 gas nitrogen (meaning it doesn't support life). After he proved that the gas produced by priestley and Scheler from the decomposition of mercuric oxide was oxygen, the composition of air was determined as nitrogen and oxygen.

The composition of air is mainly nitrogen and oxygen, which is caused by various changes in nature for a long time. Before the appearance of primitive green plants, the primitive atmosphere was dominated by carbon monoxide, carbon dioxide, methane and ammonia. After the emergence of green plants, the free oxygen released by plants during photosynthesis oxidizes carbon monoxide in the original atmosphere into carbon dioxide, methane into water vapor and carbon dioxide, and ammonia into water vapor and nitrogen. Later, due to the continuous photosynthesis of plants, most of the carbon dioxide in the air was absorbed in the process of plant photosynthesis, which made more and more oxygen in the air, and finally formed a modern air dominated by nitrogen and oxygen.

Air is a mixture and its composition is very complicated. The constant components in the air are nitrogen, oxygen and rare gases, which are almost constant, mainly because of the mutual compensation of various changes in nature. The variable components of air are carbon dioxide and water vapor. The uncertain composition of air varies from region to region. For example, the air near the factory will contain ammonia, acid vapor and so on due to different production projects. In addition, the air also contains trace amounts of hydrogen, ozone, nitrogen oxides, methane and other gases. Dust is more or less an impurity suspended in the air. Generally speaking, the composition of air is relatively fixed.