This paper introduces a wealth of knowledge in concise and understandable language, constructs a treasure house of knowledge for the majority of teenagers, and meets the teenagers' thirst for knowledge and curiosity to a certain extent. The following is why the wind farm should be built at sea, which I carefully recommend. It is for reference only. Welcome to read!
Why should wind farms be built offshore
Wind power comes from nature and does not produce pollutants, so it is a kind of green energy. However, the large-scale wind power generation system will emit a certain amount of noise, and the tall tower will also interfere with the TV signal and affect the urban construction planning. Therefore, the construction of wind power generation system should not only choose the place where the wind is strong and sustained, but also be far away from urban residential areas, such as mountain passes in mountainous areas or wide beaches.
In recent years, offshore wind power generation has been greatly developed. Compared with the implementation of wind power on land, the implementation of wind power at sea has many advantages: there is no barrier of hills and buildings on the sea, and the friction resistance of sea water to wind is also significantly less than that of land, so the wind at sea is significantly greater than that on land. Therefore, the wind energy output at sea is about 50% higher than that on land. In addition, the installation of offshore wind turbines is simple. Only 300 ~ 400 tons of special cranes are required for the installation of an offshore wind turbine, while a special construction road should be built on land.
Although the construction of offshore wind farm does not need to build roads, it needs to build a solid foundation for wind turbines. For shallow sea wind farms, the concrete foundation of the wind turbine can be sunk into the seabed like a bridge. In the deep sea, the floating hollow concrete can only be used as the foundation of the fan, and then the hollow concrete foundation can be stabilized by ropes and anchors.
In addition to building a solid foundation, offshore wind power generation facilities also need to lay submarine cables to transmit the power generated by offshore wind turbines to the shore and connect with the land power grid.
Why can't sea water be drunk?
Seawater contains a lot of salts and many elements, many of which are needed by human body. However, the concentration of various substances in seawater is too high, far exceeding the hygienic standard of drinking water. If you drink a large amount, it will lead to excessive entry of some elements into the human body, affect the normal physiological function of the human body, and even cause poisoning in serious cases.
If you drink sea water, you can take a lot of fresh water to remedy it. A large amount of fresh water can dilute the excessive minerals and elements absorbed by the human body and expel them out of the body through sweat.
According to statistics, among the people killed at sea, the death rate of those who drink seawater is 12 times higher than that of those who do not drink seawater. Why is this? Originally, in order to discharge the salts contained in 100 grams of seawater, the human body needs to discharge about 150 grams of water. Therefore, people who drink seawater not only can not supplement the water needed by the human body, but also dehydrate faster, resulting in death.
Seawater can be drunk after desalination. There are dozens of seawater desalination methods, the most important of which are distillation, electroosmosis, freezing, membrane separation and so on. Distillation is the most widely used method recently. This method first heats and boils the water to make the sea water produce steam, and then condenses the steam into distilled water. A small amount (2%) of clean sea water or an appropriate amount of mineralizer is added to the fresh water obtained by distillation, so that the water tastes delicious and supplements the inorganic salts necessary for human body due to the lack of distilled water. Under special circumstances such as maritime distress and life-saving, in order to save fresh water, some seawater and fresh water can be mixed for drinking. Some people have done experiments. People drink half the mixture of seawater and fresh water in a short time, which is generally harmless to human body.
Why do fish turn white belly after death
In life, we must have seen such a phenomenon. If a fish dies, it must be belly up. Moreover, the belly color of most fish is relatively light, close to white, so people often say that fish "turn white belly". So why do fish always have their stomach up after they die?
In fact, it is not difficult to explain this problem after knowing that fish mainly rely on the swim bladder to adjust the rise, fall and balance of the body. In most fish, there is an organ that regulates the specific gravity of the body, called the swim bladder. It can adjust the specific gravity of the body by deflating or inhaling at different depths to make it the same as the specific gravity of the surrounding water, so that the fish can stay in the water without difficulty. After the fish dies, this regulation ability is naturally lost, and the swim bladder is filled with gas, resulting in the reduction of body proportion. Therefore, when the fish dies, it will float to the water surface.
But why didn't the fish die with its back up? As long as you take a closer look at the fish's body, you will understand, because the heaviest spine grows on the fish's back, with more muscles attached to it, and the proportion is naturally large, while the abdomen is mostly internal organs, with large cavities and small proportion. Therefore, after the fish dies, the abdomen with small proportion is mostly upward.
There are other helpers with the belly up, that is, the swim bladder and fins. We already know that the swim bladder is mainly used to regulate the specific gravity of the body, while the fin is the main motor organ. The fish swims in the water by the swing of the fin. But people often ignore another function of these two organs, that is to maintain the balance of the body.
When fish are healthy, they use swim bladder to adjust density and nervous system to control motor system to adjust posture. After the fish is injured or feels the lack of oxygen in the water, the nervous system will lose control of the motor system, or the muscles have been paralyzed. At this time, the swim bladder and fins that maintain the body balance can not play a role. With the help of the air filled swim bladder, the fish will be more likely to float to the surface, and the abdomen with a smaller proportion is upward. This is also another reason for the "turning white belly" of fish after death.