4-CHLOROPYRIDINE-2-CARBOXAMIDE

Lead and mercury are strong and changeable in nature, and among all kinds of substances, they are unique. Lead is gray and heavy in color, calm and soft in nature, and often hidden in mountains and rocks. Mercury is silver-white in color, like flowing beads, and liquid at room temperature, agile and uninhibited, and volatile. Both are toxic, but they are also useful. They have been valued by alchemists since ancient times, and they are often seen in the art of alchemy.
The nature of lead is corrosion-resistant and conductive. Although it is a metal, it is rarely sharp. It is supple at first in fire, and gradually melts into a liquid with the rise of temperature, like the water of a stream, flowing freely. After being tempered, it can be turned into all kinds of utensils, or armor for protection, or materials for minting coins. Its alloy is very tough and can be used as the key to equipment. However, the poison of lead should not be underestimated. If it enters the human body, it will accumulate and not disperse, hurting the mind and the brain, causing poor qi and blood, and weakness in the limbs.
Mercury has an abnormal liveliness, seeing light and agility, and soaring when heated. In the method of alchemy, it is often used to introduce medicine, which can make various medicines and promote their changes. In the medical way, it is also used. However, the quantity must be accurate, otherwise it will cause great harm. Mercury can be turned into gold, and when it meets gold, the gold melts and fuses into one. This is its magic. However, the volatile qi enters people's lungs, injures the lungs and kidneys, and causes serious damage to vitality, so it should be used with caution.
The ancients had knowledge of the nature of lead and mercury, but they often used it at risk because they were seeking longevity. Looking at the alchemy practices of many alchemists, based on lead and mercury, they wanted immortal medicines, but in the end they could not be used, but they were poisoned and injured. Because of natural things, each has its own nature, and if you go with it, it will be beneficial, and if you go against it, it will be harmful. Although the nature of lead and mercury is wonderful, those who use it must understand its advantages and disadvantages, and treat it with scientific methods and a prudent heart. Only then can they avoid harm and benefit, and make good use of its ability.

Mercury is a highly toxic substance, and mercury disulfide (cinnabar) was widely used in ancient times. Its main uses are as follows:
First, it is used as medicine to treat diseases. In the field of traditional Chinese medicine, cinnabar has the functions of calming the nerves and calming the mind. Ancient doctors believed that it can treat palpitations, insomnia, madness and other diseases. For example, many classic medical books "Shennong Materia Medica" list it as the top grade, saying that it "dominates the body's five internal organs and all diseases, nourishes the spirit, calms the soul, nourishes qi, and brightens the eyes". When doctors concocted pills and loose ointment pills, they often used cinnabar to use its medicinal power to achieve the purpose of calming the nerves and setting the mind.
Second, it is used for alchemy. Ancient alchemists were obsessed with alchemy for the medicine of immortality. Cinnabar was rich in mercury and was a key raw material in the alchemy process. They believed that through complex refining processes, the characteristics of cinnabar could be transformed and medicinal pills with magical effects could be extracted. In the works of alchemists such as Ge Hong, there are many records of cinnabar alchemy. During alchemy, cinnabar is reacted at high temperature and its ingredients change. It is hoped that it can be refined into pills that can prolong life and even become immortals.
Third, it is used for sacrifices and funerals. The color of cinnabar is bright red like blood, and the ancients thought that it had the divine power to ward off evil spirits and exorcise ghosts and appease the undead. In sacrificial ceremonies, cinnabar is often used to draw talismans and decorate sacrificial utensils to express reverence for the gods and pray for the protection of the gods. In funeral customs, there are also many examples of the use of cinnabar. Or apply cinnabar inside and outside the coffin, or place cinnabar in the mouth or hands of the deceased, in order to protect the body of the deceased from decay, and at the same time escort their journey to the underworld from evil.
Fourth, it is used for pigments. Cinnabar is bright and long-lasting, and the ancients often used it as a pigment to paint murals, calligraphy and other works of art. Many murals in Mogao Grottoes in Dunhuang use cinnabar pigments in large quantities. After thousands of years, the color is still eye-catching, leaving precious artistic treasures for future generations. In the creation of calligraphy and painting, cinnabar is also loved by painters, used to dye the picture, adding a sense of hierarchy and gravitas of color.

The synthesis of methyl ether is not as detailed as it is today, but there are traces to follow.
To synthesize methyl ether, alcohols are often the starting point. If methanol is used as the quality, methyl ether can be obtained by a certain method. One of the methods is to use methanol as the raw material, select a suitable catalyst, and control the temperature and pressure. When methanol is placed in the reactor, an acidic catalyst, such as sulfuric acid, is added, and heated to an appropriate temperature. Methanol is catalyzed by acid, and intermolecular dehydration is combined into methyl ether. The reaction formula is roughly as follows:\ (2CH_ {3} OH\ stackrel {H_ {2} SO_ {4}} {\ longrightarrow} CH_ {3} OCH_ {3} + H_ {2} O\). In this process, the control of temperature is the key. If it is too high, methanol is easy to decompose, and if it is too low, the reaction is slow and the efficiency is not obvious.
There is also a gas phase catalysis method, which selects a catalyst with good activity, such as γ-alumina. The gasified methanol is passed through the catalyst bed. Under a specific temperature and pressure, the methanol molecules react on the surface of the catalyst. After adsorption, dissociation, and recombination, it finally forms methyl ether. This gas-phase method has good mass and heat transfer, fast reaction rate, and easy separation of the product, making it a common way for industrial synthesis of methyl ether.
In addition, dimethyl ether synthesis gas is also used to produce methyl ether. The synthesis gas contains carbon monoxide, hydrogen, etc. Under the action of a specific catalyst, methyl ether can also be obtained through complex reaction pathways, carbon monoxide hydrogenation, methanol synthesis, and methanol dehydration. This pathway can effectively utilize carbon-containing resources and has great potential in the field of energy and chemical industry.
In summary, the synthesis of methyl ether, either by methanol dehydration or synthesis gas conversion, depends on suitable catalysts and precise control of conditions.

In today's market, the genus of hardware has its own price. Among them, the price of aluminum foil often varies with time and quality.
Looking at various cities, the price of aluminum foil is about twenty to fifty yuan per catty. If it is of high quality and fine, exquisite craftsmanship, delicate lines, even thickness, and flawless, the price will increase, up to about fifty yuan. The cover is worth this price because it can be used for rare wraps and linings of utensils.
If it is used for ordinary use, and the quality is slightly inferior, the price per catty is about twenty yuan. This kind of aluminum foil, although not as delicate as the above, is also suitable for daily wrapping, covering, etc. Its workmanship is slightly simpler, and the materials used are slightly inferior, so the price is flat.
And the supply and demand of the city is also the key to the price. If it is a festive season, or the workshop uses foil, and there are many who need it, the price may be slightly higher. On the contrary, if there is no big demand, the price may be slightly lower.
The distance of the place of origin and the high and low freight also affect the price. If it is shipped from a distance, the price may be slightly higher than that of local production due to the freight.
Therefore, if you want to know the confirmed price of aluminum foil in the market, when you go to the market in person, consult the merchants, observe its quality, measure the time, and measure the demand, you can get the accurate price.

The production of charcoal is often mixed with various things. Charcoal has its advantages and disadvantages, and impurities also vary accordingly. In today's charcoal, there are several common impurities as follows:
First, ash. When charcoal is fired, although it tries its best to remove impurities, the minerals contained in the wood, etc., are mostly left as ash after combustion. Compounds such as potassium, calcium, magnesium, etc. in the charcoal body, although the amount is small, it also affects its quality. If there is too much ash, the calorific value of the charcoal will decrease, and it is easy to produce smoke and dust when burning, which is disturbing to the eyes and ears.
Second, moisture. Charcoal is easy to absorb moisture, so it often contains a certain amount of moisture. Although it is difficult to observe with the naked eye, it has a great impact on its combustion performance. When water is heated, it turns into steam, dissipating heat, causing charcoal to be difficult to ignite, and the firepower is not strong when burning. If stored in humid places, charcoal absorbs water especially, so those who are good at storing charcoal must choose a dry place.
Third, tar-like substances. During the process of firing charcoal, some of the organic matter in the wood is not completely charred, forming tar-like substances. Such impurities adhere to the surface or pores of the charcoal, which not only has a bad smell, but also easily produces thick smoke when burning, blackening utensils, and polluting the environment.
Fourth, uncharred wood. If the firing time is not enough, the wood in the charcoal or the remaining part is not completely charred. The burning speed of this part of wood is different from that of charcoal, which affects the stability of combustion, and its flammability is high, which is easy to cause uneven fire and difficult to control fire.
All these impurities are common in charcoal. To obtain high-quality charcoal, when firing and storing, pay attention to avoiding and removing it, in order to obtain its best use, and to play its role in cooking and heating.