4-pyridinecarboxaldehyde, 3-amino-

"Tiangong Kaiwu" has a saying: "It is clothing, and its main function is related to covering the body, keeping out the cold, and honoring identity etiquette." When it comes to spandex, although it is not included in the book, from the perspective of ancient times, the functions of clothing are generally the same.
In terms of covering the body, spandex is often blended with other things to make clothing, which can closely fit the human body, and there is no omission, so that people can be kept safe under the eyes.
In terms of keeping out the cold, although spandex is not the most important characteristic of keeping warm, it is mixed in the fabric, which can adjust the density of clothes and help the air retain to keep out the wind and cold.
As for the etiquette of showing identity, ancient clothing has strict regulations according to status. Although there is no such harsh distinction today, clothes made of high-quality spandex fabrics are often exquisite and comfortable, adding a touch of elegance and decency to the wearer, showing his taste of life, which is also a manifestation of his identity.
Speaking of nylon, it is also not found in "Tiangong Kaiwu". Nylon has a tough texture and good durability. When used in fabrics, it can be used as the skeleton of the clothes, making it more crisp and tangible. When covering the body, it is more stable. And nylon is not afraid of wind and rain erosion. In cold days, it can block wind and rain, protect people from warmth, and can also last for a long time. This is the ability to keep out the cold. In addition, nylon products can be made into fine clothes in the production process, which can be used in important occasions to show people's solemnity and formality, meet the needs of etiquette, and show the wearer's identity.
In short, although spandex and nylon are not ancient, they are used in covering the body, keeping out the cold, and honoring status etiquette.

Hydrogen is the beginning of all things. It is pure and light in nature. Among the elements, it has the lightest mass and often exists in the gaseous state between heaven and earth. It is colorless, odorless and tasteless, and it is difficult to dissolve in water. It is like a noble man hidden in the world, and does not blend with mundane things.
Hydrogen is flammable, and it is easy to burn and explode in case of open flames and hot topics. When mixed with air, it can form an explosive mixture. This is its violent side. It is like a hidden warrior. Once excited, it explodes with amazing power. When burned, hydrogen and oxygen combine to form water. This process releases huge energy, which is clean and efficient, like a phoenix nirvana. It exchanges its own disappearance for light and power, providing endless possibilities for the world.
Furthermore, hydrogen is reductive. In many chemical reactions, it can capture the oxygen of other substances and oxidize itself, just like a selfless devotee who sacrifices himself to achieve the transformation of others. In metallurgy and other industrial fields, with this property, metal oxides can be reduced, helping metals to regain their pure state, just like skilled craftsmen, giving metals new life.
Nitrogen is also an important element in the world. Nitrogen is chemically stable. Under normal temperature and pressure, it is like a humble gentleman, warm and peaceful, and it is not easy to react with other substances. This property makes nitrogen often used as a protective gas in food packaging. Filling nitrogen can prevent food from oxidizing and deteriorating, such as a loyal guard, guarding the freshness of food.
Under high temperature, high pressure and catalyst conditions, nitrogen can show its lively side and can react with hydrogen to produce ammonia. Ammonia is crucial in the agricultural field and is a key raw material for the manufacture of nitrogen fertilizers. It is like the rain of life, nourishing the growth of all things and bringing hope to the world. And ammonia is also used in chemical synthesis and many other aspects, and it has a wide range of uses and should not be underestimated.

An amine is unique because its nitrogen atom has one solitary child, which can be accepted. In the case of methylamine, it can be formed when it encounters acid, which is the clear property of amines. If methylamine meets an acid, it can be formed when it meets a methylamine acid, and the reaction is such as a phase, and the reaction is united.
Furthermore, amines can be replaced by nuclei. The nitrogen atom of methylamine is rich in nuclei and has nuclei. In the case of a new generation, the nitrogen atom will attack some of the positive carbon atoms in the next generation, and the nitrogen atom will form a new compound. This process is similar to the sympathetic process of amines, which is a wonder of biochemistry.
amines can also be acylated and reversed. The nitrogen atom of methylamine can be reacted with acetyl or acid anhydride, and the nitrogen atom can be replaced by an acyl group to form an amide. This reaction is like a sum, forming a new reaction.
In addition, the physical rationality of amines also affects their chemical properties. Methylamine has a special taste under normal conditions. Its boiling and solubility are closely related to the molecular force, and it is also controlled by its chemical properties. As a result, the chemical properties of methylamine are rich and rich. On the stage of chemical reactions, it is like a good dancer, who is a good dancer, and who is a good dancer.

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First, it starts with halogenated hydrocarbons. The halogenated hydrocarbons are co-reacted with sodium cyanide, and the cyanyl group can be hydrolyzed to form a carboxyl group, while the halogenated atom can be treated with ammonia water to introduce an amino group. This process is clear and the target product can be obtained step by step.
Second, aldose and ketone are groups. Aldose or ketone react with ammonia and its derivatives to form a nitrogen-containing intermediate, which can be properly converted, or carboxyl groups can be added to the molecule. For example, aldose and hydroxylamine form oximes, and oximes can be rearranged to obtain substances containing amino and carboxyl groups. < Br >
Third, the transformation of amino acids themselves. Natural amino acids can be chemically modified to change their side chains, thereby deriving amino-carboxyl compounds with different structures. For example, the carboxyl group of a specific amino acid can be modified by esterification, amidation and other reactions, and the amino group can also be protected, deprotected and other means to precisely regulate the structure of the product.
Fourth, carboxylic acid derivatives are used as starting materials. Such as acyl chloride and acid anhydride, when reacted with nitrogen-containing reagents, nitrogen-containing groups can be introduced first, and then further reacted to construct the required molecular structure, resulting in substances with both amino and carboxyl groups. < Br >
Although there are many methods of synthesis, they all need to be carefully selected according to the characteristics of the reactants, the difficulty of reaction conditions, and the purity requirements of the products. In this way, a satisfactory synthesis effect can be obtained, and the desired purpose can be achieved in the field of organic synthesis.

In the process of storage and transportation of mercury, there are general things to be paid attention to. Mercury has special properties and is toxic to its evaporation, so the first thing to do is to carefully prevent its leakage. If mercury is stored in the ground, it needs to be immediately covered with sulfur powder to make it synthesized into mercury sulfide to reduce its toxicity.
For storage, it is appropriate to use dense containers, and it should not be close to the source of fire or exposed to direct sunlight. Due to the increase in temperature, the mercury will accelerate, which is easy to cause environmental pollution and endanger personal safety.
The mercury also needs to comply with the relevant regulations. The equipment must be solid and well-packed to prevent shock and collision and cause it to break.
If there is any leakage of mercury during the transportation, it should be isolated immediately to evacuate the crowd and avoid others inhaling mercury vapor. Cleaning people should take precautions, such as gas masks, anti-mercury clothing, etc., carefully collect the leaked mercury, and then deal with it in an appropriate way.

Therefore, the storage or removal of mercury is highly important and safe, and it should be operated according to the rules to ensure the safety of the environment and people. With a little negligence, it may cause serious harm, and it may cause serious harm.