pyridine, 4-fluoro-

"What is the main use of the 4-mercury-land?" The expression "4-mercury" involved in this question is quite strange, and it is speculated that it may be "four mercury". Even so, this statement is difficult to find in the common context of traditional ancient books. If you take the perspective of "Tiangong Kaiwu" and use classical Chinese words, try to answer as follows:
Mercury, also known as mercury, is a strange thing in heaven and earth. Its nature is agile, and it is often hidden in mines such as pill sand. According to "Tiangong Kaiwu", the use of mercury is first in the art of alchemy and burning mercury. The ancient alchemists, who wanted to live forever, wanted more alchemy, and mercury was one of them. Because mercury has the ability to change, in the cauldron furnace, through water and fire, or into other things, in order to achieve the effect of prolonging life, although it is absurd, it was regarded as the norm at that time.
In addition, the art of mercury in gold gilting is also indispensable. Craftsmen use mercury and gold to make gold amalgam, which is applied to the surface of utensils. After heating, the mercury evaporates and the gold remains, so that the utensils are golden and radiant, increasing their gorgeous state. This art is often used in the decoration of bell tripods and utensils to show dignity.
And mercury in medicine is also involved. Ancient physicians used mercury and its compounds as medicine to treat scabies, sores and other diseases. However, mercury is toxic, and if it is used carelessly, it will harm the human body. Therefore, it is necessary to be cautious when using it.
Mercury is also used in some special processes, such as making mirrors. It is also useful to combine mercury and tin and apply it to the back of the mirror to make the mirror surface bright and bright, with a clear reflection, which is convenient for the world to use in daily life.
Mercury is useful in all kinds of skills and techniques. However, due to its toxicity, the user should be aware of its advantages and disadvantages and use it well.

Water is the most soft thing, but it contains magical physical properties. 4 - Water - It has all kinds of physical properties.
The first word is its state. Water is normally liquid, and when it is cold, it condenses into solid ice, and when it is hot, steam soars. "Pipe" says: "Water, the blood and qi of the earth, is like the flow of tendons." The nature of water flow, at room temperature, flows smartly, seeps through gaps, gathers when it encounters valleys, conforms to the topography, and is pervasive. And when it drops to freezing point, zero degrees Celsius, the molecular arrangement of water gradually becomes regular, like a team of soldiers, turning from smart liquid into hard ice, which can be carried on it. As for being heated, when it reaches a boiling point of 100 degrees, water molecules can break free from their shackles, turn into water vapor, and curl up into the air, diffusing formlessness.
Times and density. The density of water is quite unique. When it is liquid, it is about one gram per cubic centimeter, but after it forms ice, the density decreases slightly. It floats on water as ice, which is different from the thermal expansion and contraction of ordinary things, but instead shows cold expansion and contraction. This property is of great significance in nature. In winter, the lake is frozen, and the ice layer floats on it. It is like covering an underwater creature with a warm quilt to keep it safe through the winter.
Another is solubility. Water is known as a "universal solvent" and can dissolve many substances. Such as salt, sugar, etc., melt when entering water, and are invisible. This property is crucial to the biochemical process in the world. Many chemical reactions in living organisms depend on the dissolution of water to proceed smoothly. Nutrient transport and waste excretion are all realized by the solubility of water.
And it has a specific heat capacity. The specific heat capacity of water is very large, absorbing or releasing a lot of heat, but the temperature variation is small. It is a coastal land with a warm climate and a small temperature difference between day and night. Because seawater is like a huge thermostat, it absorbs heat in summer and dissipates heat in winter, regulating the surrounding climate.
The surface tension of water cannot be underestimated. On the surface of the water, water molecules pull each other to form an "elastic film", which can make light objects such as insects walk on it without sinking. This tension maintains the form of water, which plays an important role in both the microscopic and macroscopic worlds.
Although water is a common thing, its physical characteristics are complex and delicate, and it is indispensable for the operation of heaven and earth and the existence of life.

4 - Mercury, its chemical properties are very special. Mercury is one of the gold elements, often in the form of liquid, among the general elements, the shape is very special.
The melting temperature of mercury is very low, minus 38 to 87 degrees Celsius, so under normal conditions, it is like white water, shining with light. Its boiling temperature is 357 degrees Celsius. This property makes mercury unique in the chemical and physical processes.
Mercury has chemical activity. It can combine biochemically with many non-gold elements. In case of sulfur, the two quickly combine to form mercury sulfide. This reaction is very strong and is often used to treat mercury leakage to reduce the toxicity of mercury.
Mercury can also form alloys of gold, and this alloy is made of mercury. The formation of mercury, or the physical and chemical properties of the alloy of gold, are generally useful in metallurgy and other fields.
However, mercury and its compounds are often toxic. Mercury is easy to burn and forms mercury vapor. If inhaled, it can cause serious health damage, involving organs such as mental systems and organs. Therefore, in the treatment and use of mercury, we should be careful and follow safety measures to prevent the harm of mercury poisoning. In addition, the chemical properties of mercury not only show its chemical reaction and industrial use, but also need to be carefully treated because of its toxicity, and its advantages and disadvantages should be weighed in order to achieve reasonable utilization.

If you want to make "4-river" utensils, there are various methods, and listen to me one by one.
First, it is very important to choose the material. You can find tough wood, such as nanmu and sandalwood, which are strong in quality and not easy to fold, and can support the use of utensils. When cutting wood, when the texture of the wood is smooth, it will make the subsequent utensils smoother. Or find good stones. Those with dense texture are better. The strength of the stone can ensure the durability of the utensils.
Second, the craftsmanship of the utensils is fine and complicated. If you use wood as the material, you need to prepare sharp blades, such as saws, axes, planers, etc. First, cut the wood to the required length, and cut the shape with an axe to remove the branches and vines. Then it is finely ground to make the wood surface as smooth as a mirror, without any unevenness. If stone is used, the carving work is indispensable. Hold the chisel and hold the hammer, and carve slowly according to the pattern drawn in advance. Every stroke needs to be accurate, and if there is a slight mistake, all efforts will be wasted.
Third, consider the structure of the utensil. The utensil of "4-river -" must have its specific structure to be used. Either it is hollow and contains objects; or it is symmetrical and seeks its balance. The design of the structure needs to be carefully considered, taking into account practicality and beauty.
Fourth, assembly and debugging should not be ignored. If the appliance is composed of multiple parts, it needs to be tightly fitted when assembling, connected by tenon and mortise, so that the parts fit well. After assembly, debug it again to see if it works smoothly, if there are any obstacles, and if so, trim it until the appliance reaches the best state. In this way, you can get the "4-river -" fine appliance.

Today there is a question, "What is the price range of 4-Jiang- in the market?" This matter is related to the price market, but if you want to clarify its exact value, you need to look at many reasons.
The price of the husband's market often varies according to time, place, quality, supply and demand. If you talk about "4-Jiang-", let's say it is a product, and the origin is different, and the price is also different. Its place of origin, because there is no transshipment fee or intermediary benefit, the price may be slightly lower; if it goes to the distant market, the price will increase due to the addition of freight, taxes, and merchant profits.
Changes in time also affect the price. In the season of its output, the supply of goods is abundant and the supply exceeds the demand, and the price may drop; in the non-production season, the supply is less and the demand is numerous, and the price will always rise. And its quality is good or bad, and it also affects the price. The quality of the first-class, the materials are all fine, and the price is high; the second-class, the price is inferior.
As for the trend of supply and demand, it is particularly critical. If the world is still there, everyone is competing for it, but the production is not enough, the price will rise; if few people are interested, the goods will be accumulated and difficult to sell, and the price will fall.
However, I don't know what "4-Jiang-" is, it is difficult to determine its price range. If it is a rare treasure or a rare artifact, the price may be high; if it is an ordinary thing or an easily available product, the price may be average. If you want to know the details, you must visit the general market in detail, and only by examining the current supply and demand and the high quality can you get its approximate price range.