2-pyridinealdehyde

Among the many processes involved in "Tiangong Kaiwu", where glauberite is mentioned, its main uses are roughly the following categories.
First, in the salt making process, glauberite can be used to clean salt. When the sea is boiled as salt, in addition to sodium chloride, there are still many impurities in the seawater. Glauberite can react with some impurities to help it precipitate, thereby improving the purity of the salt. For example, "Where the brine is first produced, its color is turbid, and it is cast with glauberite. Over time, the impurities settle, the brine gradually clears, and the salt cooked is pure in color and white matter." This is to use the chemical interaction between glauberite and impurities to achieve the purpose of purifying salt and ensure that the salt produced is of good quality and meets the standards for food or other purposes.
Second, in the papermaking process, mirabilite also has important uses. Papermaking requires raw materials such as bamboo to be made into pulp, and mirabilite can accelerate the decay and decomposition of raw materials. For example, "To make bamboo paper, first cut the bamboo into sections, soak it in a pond, add mirabilite and other substances, and after a few months, the bamboo will gradually rot and be easy to be pounded into pulp." It can shorten the processing time of raw materials to a certain extent and make the fiber decompose more fully. The paper produced in this way has a more uniform texture, fineness, and good toughness, which plays a key role in improving the quality of paper.
Third, in the field of metallurgy, mirabilite can be used as a flux. In the process of metal smelting, ore often contains various gangue and other impurities. After adding mirabilite, it can reduce the melting point of the slag and make the slag and metal better separated. For example, "When smelting copper, the ore and mirabilite are placed in the furnace together. Under high temperature, mirabilite helps the slag flow, and the copper liquid is pure and easy to extract." This helps to improve the purity of metals and the efficiency of smelting, which is very important for the development of metallurgical processes.

The flintlock of the sun is an artifact that takes fire from the sun. It is a thing, made of gold, like a mirror, round and dented. The physical properties of this flintlock of the sun can be particularly investigated.
One is reflective. Its surface is smooth like a ridge, which can reflect the image of an object. When the sun shines, the light reflects out. With its round dome shape, the light gathers at one point, and the heat rises sharply at this point. The sage of ancient times, observing this characteristic, used the sun to gather light under the sun to make a fire for cooking and lighting.
Second, the material is gold. The gold is tough in texture, not easy to rust, and can be stored and used for a long time. Its thermal conductivity is also good, light and heat are concentrated on the sun flintlock, although the point is small, the heat is transferred to the gold body, which can also make its temperature rise, and because of the good conductivity of gold, the heat does not dissipate in useless places, but more in the expected ignition.
Third, the shape of the sun flintlock is round. Round, the circumference is well-proportioned, and when the light is reflected, the light can be evenly concentrated without the risk of deflection. Dam, concave shape, this shape has the effect of collecting light and gathering energy, so that the scattered sunlight is concentrated in one place, and the power is greatly increased.
From this perspective, the sun flintlock, with its physical properties such as reflective, gold, and round depression shape, became an essential tool for the ancients to make fire. It has extraordinary functions in everything in life. It is actually the manifestation of the wisdom of the ancient sages, and it is also a precedent for later generations to explore physics.

Under normal conditions, nitrogen dioxide is very fixed, and other things are reversed.

In the past, the family used methods to reduce its activity. In the ordinary environment, when it encounters nitrogen dioxide, it is like a stone sinking into the sea, and it is transformed. That is, it is placed in the height of fire, and it is also reduced in the slightest. This is also the effect of its transformation.
However, if the world is difficult, if special methods are applied, nitrogen dioxide can also develop its activity. If a certain catalytic agent is introduced, or in a high-temperature cold environment, nitrogen dioxide can also be reversed and other substances can be transformed.
From this, it is often determined that the chemical properties of nitrogen dioxide can be determined. However, in case of extraordinary problems, it can also be changed and changed. Its performance is not good, and it is not suitable for the outside world.

To make two methods, the ancient methods, each has a wonderful reason. First, when gold encounters acid, such as dilute sulfuric acid, it can escape. The reverse image, dissolving, soaking up, because of the sexual activity, can be replaced in the acid, and then it becomes sulfuric acid, and then it is obtained. The text says: "Add dilute sulfuric acid, and get sulfuric acid." This is easy to do, and it is often used to take the method in the room.
There is also a way to dissolve water. Water is also a phase of oxygen and things. Through the flow of direct current, the water then divides and generates oxygen. This can make water molecules disintegrate, and the oxygen is in its place. In the process of production, all bubbles are produced, which is more than the amount of oxygen, and is formed in the water, so that the two oxygen are the same. This effect, of course, requires energy, and the use is high.
In addition, when the carbon of water vapor meets the red carbon, it can also be produced. Carbonaceous, at high temperatures, it can be evaporated with water, and it can be produced with oxygen. In this way, a mixture of carbon monoxide is obtained, which is called water and coal. Its reverse effect requires high temperature, but in terms of engineering, it is also the way to take it.
Another method is to use gold compounds to react with water. Metallic compounds, such as chemical compounds, meet the strong reaction of water, and the oxygen root of the water in the chemical compound converges, and the product is produced. This reaction is fast, convenient and easy to implement, and is needed in the wild.
All these methods are the method of making two systems, each with its own advantages and disadvantages. Those who are good at their own feelings and purposes.

In the way of raising eels, there are several things to pay attention to when storing and transporting them.
When storing, the first choice is to choose a pool and marsh. The pool should be built in a cool place to avoid direct sunlight and keep the water temperature suitable. The size of the pool should depend on the number of eels. It should not be too narrow, so that the eels have no swimming space or too wide, which makes management inconvenient. The bottom of the pool should be paved with fertile soil and fine sand, about several inches thick. This is to create a habitat for the eels, and to help them hide and forage. At the same time, the pool should be planted with aquatic plants, such as duckweed and water hyacinth. One can shade the sun and cool down, and the other can purify the water and create a natural ecology for the eels.
Second words about water quality, water is the foundation of eel survival, and its quality is very important. The water must be clean, free of filth and odor, and the water should be changed regularly to keep the water fresh. However, when changing the water, the water temperature should not be changed suddenly, and the temperature difference should be controlled within a few degrees, otherwise the eel is prone to disease. And the amount of dissolved oxygen in the water should not be ignored. An oxygenator can be installed to keep the eel's breathing smooth.
As for transportation, the eel's constitution is delicate and vulnerable to damage on the way. It is advisable to stop eating for a few days before transportation to empty the eel's abdomen and reduce the pollution of excrement on the water quality during transportation. When loading the eel's utensils, it is advisable to use soft objects, such as papyrus, sponges, etc., to prevent The water used for transportation also needs to be clean and the water temperature is suitable. Regular observation on the way. If there is any abnormality in the eel, it should be disposed of as soon as possible.
Furthermore, the density during transportation should not be too large. If it is too crowded, the eels are easy to die due to hypoxia and mutual extrusion. When the number of eels is reasonably arranged according to the size of the container and the length of transportation, each eel should have sufficient space and oxygen. In this way, during the storage and transportation of the eels, all things should be paid attention to to to ensure the survival and health of the eels.