How to live in the anti -season marketing, how do you spend summer in the "down jacket"?

With the advent of the hot summer, the heavy winter clothes in the closet have long been replaced by the thin summer dress. When I clean up the winter clothes, I wonder if you have doubts. Why can down jackets be as light as summer, but so warm?

1. Why is the down so warm?

The down is different from feathers. (Used for clothing) grows down in the body of the ducky, the sheeter, and the roots of the duck and the goose. The body surface of the goose, although the texture is very light, it has a certain toughness, not as soft as the down.

The basic constituent units of down are the vascular bundle cells composed of single or multi -rooted tubular bundles. There is a layer of cell membrane on the surface of these dimensions, which are mainly composed of two macromolecules with hydrophobic properties. The formation of vascular bundle cells formed is curled, so there is a large amount of pores in the down. These pores can store a certain amount of air. At the same time, there is a scolding force between the feathers in the down fiber structure, which makes it not close to the feathers, but to maintain a certain distance and further improve the ability of down storage of down. Essence

Source ｜ PEXELS

There are three ways to transmit heat, namely heat transmission, heat -to -flow, and heat radiation. Thermal conductors pass the heat through mutual contact, such as we cover our hands with a hot water bag. The heat to the flowing medium passs heat, such as the warm air and air conditioner in the winter house to warm the entire room. Thermal radiation transmits heat through radiation electromagnetic waves, such as people to heat the sun.

Because the flowing air is easy to take away the calories, the heat conducting coefficient of relatively low thermal conductivity of the relatively static air can be used as a barrier for heat transfer. The more static air, the better the heat insulation and thermal heating effect. The down structure enables it to store the air in large quantities, so it fills the down of down clothes with excellent warmth, and this performance will continue to increase with the increase of the volume (that is, the increase in fluffy).

The more fluffy, the warm the down

Source ｜ Baidu Encyclopedia

2. How do you spend summer in the "down jacket"?

Birds have feathers, and there are down on the body surface under the feathers. With these feathers and down, the birds have survived the winter and winter. But when the summer arrives, this feather and down will cause obstacles to the surface heat dissipation. Aren't birds afraid of heat?

"Velvet content" is a very high golden crown wearing chrysanthemum

Source ｜ Baidu Encyclopedia

In fact, most birds cannot withstand too high body temperature, which may cause its shock or even death. In addition, the birds are often flying and the basic metabolic rate is high. Under the same temperature, the temperature that the birds feel more than we feel, so the birds really need to help in some special ways to help help in help Cool it yourself.

Before understanding the skills of bird cooling, we must first clarify a fact: not all birds are full of feathers. In fact, there are only a few birds covering feathers, such as penguins. Penguins are mainly living in Antarctica. Considering the cold climate of Antarctica, the penguins here do not need to worry too much about whether it will heat up in summer; and penguins living in other regions such as Galapagos penguins can be "soaked" in the sea water. Cool it yourself.

Source ｜ Unsplash

Most of the bird's surface is divided into feather areas and naked areas, that is, the area of ​​feathers and areas that does not grow feathers, and the naked area is an important channel for birds to dissipate heat. When the temperature rises, the birds will lift the feathers and expose the naked area to the air to emit some heat. If the temperature continues to rise, the birds will release the calories by expanding the capillaries and increased blood flow by expanding the capillaries. The area of ​​the naked area of ​​the bird surface is relatively small, so birds will increase blood flow more efficiently.

Single Chicken Crown Ordinary Hengsheng's Feather Area and Naked Area

Source ｜ "Feather: Miracle in Natural Evolution"

Some birds, such as gulls and herons, can increase the blood flow of their bare legs and feet by 20 times, so as to quickly release the heat into the air. There are also some birds that hang their legs down during the flight, and their purpose is to dissipate heat. Some birds even heat dissipate through the nude skin and mouth around the eyes, so many tropical birds have evolved their mouths to expand the area of ​​the body heat dissipation.

Put your legs and heat the heat while flying

Source ｜ Unsplash

The airbags are a cystic structure connected to the lungs. The birds mainly have 9 airbags. These airbags are wrapped in their internal organs and extended to the bones of the legs and wings. When the birds inhale, the gas does not directly enter the lungs, but enters the first airbag; when exhaling, the previous inhaled gas enters the lungs. When inhaling again, the first inhaled gas will be pushed into the second airbag, and the gas that has just been inhaled enters the first airbag ... so repeated, the inhaled gas of the bird will continue to flow and take away the calories in its body and take away the calories Such an efficient respiratory system continues to help birds distribute heat and keep it stable in body temperature in hot weather.

Source ｜ Baidu Encyclopedia

We found the down from the birds that can keep warm, and then began to find the answer to how to avoid the summer heat. Maybe while studying this question, scientists have new doubts, mysterious charm of nature and human progress of human progress. That's how the motivation is.

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