1 - 2, 3, 4, 6 - The four rivers are the rivers, the rivers, the rivers, and the rivers. Their main use is the river, which is as important as water conservancy, transportation, and people's livelihood in the world.
Since ancient times, the river has been vast, the north and south, and the waterways in the south. Its flowing land is fertile and thousands of miles, irrigating the fields, so that the people can get enough food and clothing. And the boats and boats go to it, making it easy to multiply the things, and promoting the communication and exchange of the land. It is a great contribution to the prosperity of the river.
The river is also the mother of the Chinese people. It gave birth to ancient civilizations and nourished the summer land. Along the river basin, the population is dense, and the cities rise. The water conservancy of the river can be used for irrigation, and it can also be used for transportation. The ancient dynasties declined, and many of them were related to each other. The kings of the ancient dynasties did not pay attention to the management of the river, so as to ensure the safety of the people and the prosperity of the family.
Those who are located in the north and south, are connected to the water. The benefits of irrigation benefit the land of Huai, so that the And the traffic channels, the goods of the north and the south are circulated from this place, and the cultural integration of the north and the south is promoted.
Those who are not as flowing as rivers and rivers, but they also played an important role in the ancient world. Water is used to irrigate the fields and nourish the people. And it is one of the water systems, which is connected to other waters, forming a large water conservancy, and the water conservancy and transportation in the region cannot be ignored.
In terms of water conservancy irrigation, transportation, exhibition, cultural support and other aspects, they are all the most important, and they are all indispensable to the world.

1-2,3,4,6-tetralaphthalene is a chemical compound with special physical properties. It is a liquid-colored liquid, and it is flowing under normal conditions. The taste is slightly similar to gasoline, insoluble in water, and easily soluble in ethanol, ether, etc. This is due to the principle of similar phase solubility. Its molecular properties make it soluble and well miscible.
1-2,3,4,6-tetralaphthalene has a low melting temperature of -31 ° C. This property allows it to still hold liquid at low temperatures. The boiling temperature is 195 ° C, and the boiling phase is high, indicating that the molecular force is low, and it needs to supply more energy from the liquid.
Its density is less than that of water, < 0.97g/cm ³, so if the water is mixed, it will float on the water surface. The steaming density of 1-2,3,4,6-tetralin is greater than that of air. Once it is released, it is easy to polymerize at low temperatures.
Furthermore, 1-2,3,4,6-tetralin is flammable. In case of open flame and high energy ignition and explosion, because its molecules contain carbon elements, it can be burned with sufficient oxygen energy, and a large amount of fuel is released. In the chemical industry, it is often used as a raw material for synthesis. In the synthesis of certain fragrances and compounds, it can be customized according to the characteristics of its molecules.

What are the chemical properties of copper tetrahydrate? Let me tell you in detail.
This copper compound has a beautiful blue color and is mostly found in the solution of various copper salts. Its properties are relatively stable, and it rarely changes spontaneously under normal temperature and pressure.
In terms of its reaction with acids, it is difficult to react significantly when encountering strong acids such as hydrochloric acid and sulfuric acid without special conditions. Because copper ions have a stable coordination structure in acidic solutions, the structure of copper tetrahydrate is relatively firm and cannot be easily broken by ordinary strong acids.
When encountering strong bases, it is a different scene. Hydroxide ions of strong bases can undergo coordination substitution reactions with copper ions tetrahydrate. Hydroxide ions have strong coordination ability and can gradually replace water molecules to form copper hydroxide precipitation. The color of this precipitation is light blue, which is quite eye-catching. Therefore, the structure of copper ions tetrahydrate is easily damaged in an alkaline environment.
Furthermore, copper ions tetrahydrate have certain oxidation properties. In case of appropriate reducing agents, such as active metal elements, copper ions can obtain electrons and be reduced. Taking iron as an example, when iron is added to a solution containing copper ions tetrahydrate, iron atoms lose electrons and become ferrous ions, and copper ions get electrons and precipitate red copper elements. This reaction proves that copper tetrahydrate ions can exhibit their oxidizing properties under appropriate conditions.
Under heating conditions, the water molecules of copper tetrahydrate ions can be gradually lost. As the temperature increases, the blue copper tetrahydrate ions gradually transform into anhydrous copper salts, and their color also changes. This phenomenon is also one of the unique manifestations of the chemical properties of copper tetrahydrate.
To sum up, the chemical properties of copper 1-poisonous-2,3,4,6-tetrahydrate are rich and diverse, and they exhibit different chemical behaviors under different environmental conditions. It is an interesting object in chemical research.

"Tiangong Kaiwu" says: "Where a mirror is cast, gray sand is used for the mold, and tin and copper are used for copper." The method of casting mirrors contains many delicacies, and there is also a way to make billets.
Cast 1-mercury-2,3,4,6-tetrafluoroboron billets, the first material selection. Choose refined copper, its quality is pure and stable, and the billets are excellent if there are few impurities. Tin is also the key. It is necessary to choose pure ones and fuse them with copper in an appropriate proportion. These two are the foundation to lay the foundation of the billet.
When casting billets, molten copper is necessary. First put the copper in the crucible and calcine it with fierce fire. When the copper melts into molten gold, the shape is like a running fire and shining, and then the tin is slowly put in in proportion. At the same time, it is quickly stirred with a long rod to make the copper and tin blend evenly, just like water milk.
The system of casting mold is related to the forming of the blank. With special ash sand, carefully pounded to make it tight and delicate. The ash sand is moderately dry and wet. If it is too dry, the mold will crack easily, and if it is too wet, it will cause pores in the casting billet. The prepared ash sand is placed in the mold frame, compacted and scraped flat to make a casting mold.
There is also a trick to casting the melt. When the temperature of the copper and tin melt is moderate, it is slowly injected into the mold in a stable and accurate manner. The process of liquid injection needs to be completed in one go and must not be interrupted to prevent faults.
Wait for the casting mold to cool, which is the key to the formation of the blank. Cooling should not be too fast or too slow. If it is too fast, the blank will be brittle, and if it is too slow, it will take too long, which will affect the quality. It is necessary to grasp the appropriate cooling rhythm according to the size and thickness of the blank.
After cooling is completed, carefully remove the gray sand of the casting mold and take out the billet. At this time, although the billet is in its initial shape, there may be defects on the surface. It needs to be polished and trimmed with fine tools to remove its burrs and make it smooth and flat to obtain a qualified 1-mercury-2,3,4,6-tetrafluoroboron billet.

1-2,3,4,6-tetralaphthalene is in storage and storage, and the following general things should be paid attention to:
First, the temperature is very important. This compound should be stored in a safe place, in a safe place, and at a safe fire source. Because of its flammability, it is easy to cause fire and other conditions in a high environment. If it is stored in an inflamed place and does not know where to go, it may gather in an open fire, and it will ignite instantaneously and form a large one.
Second, the packaging must be used. A packaging container that meets safety standards needs to be used to prevent leakage. The packaging material needs to be able to withstand the corrosion of this compound and be well sealed. If the package is damaged, 1 - 2, 3, 4, 6 - tetralin will not be released, which will not cause the material to be lost, and the damage may pollute the environment and endanger the health of the surrounding people.
Third, be careful on the way. Oxidation, acid and other substances are divided into different parts to avoid anti-biotic reactions. Due to its chemical activity, oxidation can easily lead to strong oxidation reactions, which may cause explosion.
Fourth, the operator needs to be well-trained, familiar with its dangerous characteristics and emergency measures. During the operation process, it is necessary to wear anti-corrosive materials, such as anti-corrosive gloves, gas masks, etc., to prevent the skin from inhaling the steam.
Therefore, the storage of 1-2,3,4,6-tetra-naphthalene should be controlled to ensure the safety of people, environmental hazards and material integrity.