5-bromopyridine-3-carbaldehyd

In "Tiangong Kaiwu", the main use of 5% borax is related to many fields, and it is particularly critical in hardware metallurgical casting.
Borax is used in metallurgy and can be used as a flux. When casting copper in ancient times, an appropriate amount of borax can effectively reduce the melting point of copper ore, make copper more easily melted, and reduce the friction between the liquid metal and the furnace wall, making the liquid metal flow better. The copper ware cast in this way has a uniform texture, less bubble trachoma, and high quality. Borax plays an important role in welding processes, such as exquisite bronze ritual vessels, practical copper tripods, and bronze mirrors.
In the welding process, borax is also indispensable. In ancient times, when craftsmen welded metals, borax could remove the oxides on the metal surface, avoid the re-oxidation of the metal during the welding process, and make the welding more firm. For example, to create exquisite gold and silver utensils, different parts need to be welded and spliced. Borax guarantees the welding quality, makes the structure of the utensils stable, and the decorative patterns can also be perfectly connected.
Furthermore, in the field of alchemy, borax also occupies a place. Alchemists believe that borax has unique chemical properties, which can participate in the refining reaction of alchemy pills and change the composition and properties of alchemy pills. Although the theoretical part may be unscientific, it objectively promotes the exploration of the properties and uses of borax.
In summary, 5% borax has important uses in ancient metallurgy, welding, and alchemy, and has made significant contributions to the development of ancient technology.

If you want to make 5-hydroxytryptamine, there are various ways to synthesize it. Although "Tiangong Kaiwu" does not directly describe 5-hydroxytryptamine, there are many inspirations for the preparation of it.
One is that it can be extracted from natural materials. In the past, all kinds of medicines were mostly taken from plants and stones. If you look for plants rich in the precursor material of 5-hydroxytryptamine, you can get it. For example, some plants contain tryptophan in their bodies, which is the key raw material for the synthesis of 5-hydroxytryptophan. In ancient times, such plants can be picked, dried, ground, and then impregnated with solvents such as water or wine to dissolve tryptophan. After the residue is filtered off, the solvent is evaporated, or the crude product can be obtained. However, there are many impurities in it, and it needs to be repeatedly refined, or sublimated and recrystallized to obtain a purer product.
Second, the way of chemical synthesis. Although there is no fine chemical industry in ancient times, there are still things to be explored based on the principle of chemical change. Tryptophan can be converted into 5-hydroxytryptamine by chemical reaction. First, use appropriate reagents to make a substitution reaction in specific parts of tryptophan, introduce hydroxyl groups, and simulate the process of natural synthesis. Pay attention to the conditions of the reaction. Temperature and pH are all related to success or failure. Ancient alchemists were good at adjusting the temperature. In today's chemical synthesis, temperature is also the key. Or you can control the reaction temperature according to the season and hour, because although there is no accurate thermometer at that time, there is also a way to judge the temperature based on experience. The pH can be adjusted by natural acid and alkali substances, such as vinegar for acid and lime for alkali. Add it cautiously and watch the reaction change.
Third, the method of biological fermentation. There are ancient techniques of brewing wine and making sauce, which are all the power of microbial fermentation. Microorganisms that can synthesize 5-hydroxytryptamine can be found and cultured in a suitable medium. Choose a medium such as whole grains to provide nutrients for microorganisms. In a clean urn or tank, add the strain, seal it, and let it stand in a suitable place. During the growth and metabolism of microorganisms, 5-hydroxytryptamine may be produced. After fermentation, the bacteria and products can be separated by filtration, centrifugation, etc., and then purified later.

Mercury is one of the metals, and its unique properties are different from other things.
Mercury is in the shape of a liquid at room temperature, and the silver optical flow is very flexible. This is its most obvious physical property. Unlike other metals, which mostly exist in a solid state, mercury is in a liquid state, just like silver water, slippery to touch and difficult to hold.
The melting point of mercury is extremely low, only -38.87 ° C, so it is always liquid in normal temperature environments. However, its boiling point reaches 356.6 ° C, and the span between the melting point and the boiling point is quite large. This property is also unique to mercury.
Furthermore, the density of mercury is very high, about 13.59 grams per cubic centimeter, which is more than ten times that of common water. Therefore, if mercury is placed in water, mercury will sink to the bottom of the water, like a heavy object falling into an abyss.
Mercury has a large surface tension, so it often gathers into silver droplets on a flat surface, which are round and full, and roll freely, not easy to disperse.
Mercury also has unique electrical conductivity. Although it is a metal, its electrical conductivity is slightly inferior to that of good conductors such as copper and silver, but it can still conduct current, which is also useful in the field of electricity.
In addition, mercury has a certain volatility, and it will slowly evaporate into mercury vapor under normal temperature. This mercury vapor is colorless and odorless, but it is toxic, invisible, and easy to be ignored, and if people inhale too much, they will suffer from it.
View the physical properties of mercury, strange shape, special melting point, density, tension, conductivity, and volatile toxicity. It is a metal with unique physical properties. It is useful in many fields and needs to be treated with caution.

Those who have mercury are soft and good at flowing. At room temperature, they are liquid, like the rolling of pearls, agile and uncertain. Its color is silver-white and shining, like the condensation of moonlight.
Mercury's chemical properties are lively and unique. It is easy to vaporize when heated, rising in the void, like smoke curling, but this gas is highly toxic and must not be smelled lightly. It can combine with many metals to form amalgam, which is a wonderful transformation. If it meets gold, it will melt in mercury, and the two will blend seamlessly, just like water and milk, which can be used as a metallurgical aid.
Mercury in acid, when it encounters strong oxidizing acids, such as nitric acid, will react violently. Mercury is oxidized to form mercury salts, and at the same time, gas escapes, and it looks like bubbles surging, like boiling soup. And its compounds are diverse in form and have their own characteristics. Mercury oxide, red or yellow, decomposes when heated, produces oxygen, and mercury returns to the liquid state. This change is like reincarnation.
Furthermore, although mercury is liquid at room temperature, it has the same properties as metals and can conduct electricity and heat transfer. Although it is slightly inferior to common metals, it should not be underestimated. It has a wide range of uses in the field of chemistry, including pharmaceuticals and chemicals. However, its toxicity is very strong, if inadvertently exposed or inhaled, it can be very harmful, damaging to people's internal organs, and confusing people's minds. Therefore, when using it, we should be extremely cautious and must not take it lightly. Only by taking safety as the key can we make good use of the characteristics of mercury and use it for the world.

The price of maize varies with the supply and demand of the market and the change of time. When the time is right, the weather is smooth, the land is profitable, the farmers work diligently, and the production of maize is abundant, the price may be flat and stable. In case of natural disasters, the genus of drought and flood insect infestation causes the production and damage of maize, the price must be increased.
And the state of trade between the four sides is also related to the price of maize. The four sides of the road, the merchants converge, the goods flow smoothly, the supply of maize is sufficient, and the price is easy. If the road is blocked, the transportation is difficult, or other parties are in urgent need, and the goods are in short supply and the demand is numerous, the price will be high and difficult to suppress.
Furthermore, the government decrees of the country have a huge impact on the price of maize. The government uses government to guide farmers, reward hard work to promote production, or store grain for shortage, and adjust supply and demand, all of which can make the price of maize stable. If the government changes, or re-levies, or relaxes the ban, the city will also move accordingly, and the price of maize will fluctuate.
Overall, the price of maize in the market can not be determined at one end. It depends on the weather, geographical location, personnel, and decrees, which are intertwined and affect each other. Therefore, if you want to know the exact price, you must carefully observe the current situation and review all things in order to obtain it. In the market, the peddlers and pawns often talk about the price of maize, because it is related to people's livelihood and the livelihood of everyone.