3-Bromothiophene-2-carboxaldehyde

"Tiangong Kaiwu" says: "Where ramie has no soil and no growth, it can be planted by law, or sprinkled, or rooted, and after planting, it will grow over the years." Ramie, an ancient fiber crop in our country, has unique physical properties and a wide range of uses. It is a godsend.
Ramie fiber is slender and tough, with high strength, and the tensile strength can reach 60-90cN/tex, much higher than the common cotton fiber, about 2-3 times that of cotton fiber. These high-strength characteristics make ramie fabric extremely durable, and it has been rubbed over time. In ancient fabrics, ramie is relied on to increase its fastness and will not be damaged for a long time.
It has excellent moisture absorption, can quickly absorb and emit human sweat, and feels dry and comfortable when wearing ramie clothes in summer. It has the reputation of "natural air conditioner". According to estimates, the moisture absorption rate of ramie can reach 13-15%, and the moisture release rate can reach 8-9%, far exceeding similar fibers. Such excellent moisture absorption and moisture dissipation properties are the first choice for the ancients to cool off in the hot summer.
Ramie fiber also has natural antibacterial and antibacterial properties, and has a high inhibition rate on common bacteria such as Escherichia coli and Staphylococcus aureus. Fabric woven with ramie is not easy to breed bacteria and emits peculiar smell after long-term use. The ancients often used ramie to make bed nets and clothes to keep clean and healthy.
The heat resistance of ramie is also outstanding. In high temperature environments, its fiber structure is stable, and it is not easy to deform or change color. In ancient cooking and working places, ramie fabrics were often used as protection, which was not afraid of fireworks and roasted, and could also maintain a good shape.
In addition, ramie is crisp and has a natural luster. It is woven into silk, with clear texture and unique texture, showing the beauty of simplicity and elegance. After dyeing, the color is bright and lasting, adding a different style to ancient clothing and fabrics.
Overall, ramie has superior physical properties and plays an important role in many aspects such as ancient clothing and use. It is really a treasure given by heaven and earth.

3-Bromopentane and 2-methylbutane are both organic compounds with unique chemical properties.
First, 3-bromopentane, which is active due to the functional group containing bromine atoms. A typical substitution reaction of halogenated hydrocarbons, 3-bromopentane can occur. When heated in an aqueous sodium hydroxide solution, the bromine atom will be replaced by a hydroxyl group to form 3-pentanol. This reaction is nucleophilic substitution. The hydroxyl negative ion attacks the carbon atom connected to the bromine as a nucleophilic reagent, and the bromine ion leaves. When heated in a sodium hydroxide alcohol solution, a elimination reaction will occur to form pentene. Because the beta-hydrogen atom and the bromine atom are removed from the hydrogen bromide in a basic alcohol solution, a carbon-carbon double bond is formed. In addition, 3-bromopentane can also react with a variety of nucleophiles such as sodium cyanide. The bromine atom is replaced by a cyanide group, and the product can be further hydrolyzed to form carboxylic acids, which are widely used in organic synthesis.
Besides 2-methyl butane, it belongs to the alkane class. Alkanes are relatively stable in chemical properties and usually do not react with strong acids, strong bases and strong oxidants. However, under certain conditions, substitution reactions can occur. When exposed to light or high temperature, they can undergo free radical substitution reactions with halogen elementals (such as chlorine gas). Taking the reaction with chlorine as an example, chlorine radicals capture hydrogen atoms in alkane molecules to form halogenated hydrocarbons and hydrogen chloride. Due to the different activities of different types of hydrogen atoms in the structure, the substitution position is selective. Generally, the activity of tertiary hydrogen is higher than that of secondary hydrogen, and the activity of secondary hydrogen is higher than that of primary hydrogen, so the proportion of substitution products varies under different conditions. In addition, 2-methylbutane can be burned in oxygen and completely burned to produce carbon dioxide and water, which is the oxidation reaction that occurs as a fuel, releasing a lot of energy.

Mercury has a wide range of uses, but it is also harmful. As for the synthesis of mercury, the ancients have explored it a lot.
One of the common methods is the technique of burning Dan sand. For Dan sand, mercury sulfide is also. The ancients placed Dan sand in the cauldron and applied heat. "Baopuzi Inner Chapter" says: "Dan sand is burned into mercury, and it accumulates and becomes Dan sand." The cover is heated and decomposed by Dan sand, in which sulfur and mercury are separated, and mercury escapes in a gaseous state. When cooled, it condenses into liquid mercury. This process needs to be well controlled by the heat. If the fire is fierce, the mercury is easy to fly away, and if the fire is small, it cannot be decomposed.
The second is the method of combining aluminite and gall. Aluminite and gall are common minerals. Alumite and bile alum are co-placed in an airtight container and calcined. The components in alumite interact with bile alum, and mercury can also be obtained through a series of complex chemical reactions. This change is related to the principle of five elements to produce grams. Alumite belongs to soil, and bile alum belongs to water. Water enters the soil and is refined by fire. The five elements sympathize, and mercury is precipitated.
The third is the method of replacing metals with mercury-containing ores. The ancients have observed that some metals are more active than mercury. When metals such as iron and zinc are placed in a solution of mercury-containing ores, the metal can replace mercury from its compounds. If iron is put into a mercury salt solution, the iron atom loses electrons, and mercury ions gain electrons and precipitate into mercury elemental matter. This is based on the difference in metal activity, and the act of replacement is like the appearance of a strong bin dominating.
However, although all kinds of synthesis methods are ingenious, mercury is toxic and volatile. When operating, if there is a little carelessness, mercury gas will permeate, hurting people's organs and spirits. Although the ancients did not know the scientific principle of mercury poisoning, they gradually realized its harm in practice, so the synthesis of mercury was mostly done with caution.

"Sulfur is the liquid of stone, and there is also soil sulfur. In its growth, the liquid of stone appears, like yellow alum, while it is as strong as stone, and its soil sulfur is born in the soil cave." Sulfur is widely used and has important applications in many fields.
In the field of alchemy, alchemists place great importance on sulfur. The method of alchemy is to pursue the elixir of immortality. Sulfur is often selected as a raw material for alchemy because of its special chemical properties. Alchemists mix it with various gold and stone medicines and refine it with a fire, hoping to refine a magical elixir. As described in Ge Hong's "Baopuzi" in alchemy, sulfur is often used.
In the field of medicine, sulfur is also useful. " In the Compendium of Materia Medica, sulphur is warm in nature, sour in taste, toxic, and can be used to treat a variety of diseases. For example, skin diseases such as scabies and sores, sulphur is used as medicine, or taken internally, or used externally, and has a certain curative effect. When used externally, it can kill scabies; when taken internally, it can replenish fire and help yang and laxative, and has an auxiliary effect on symptoms such as deficiency and cold constipation.
In the military field, sulphur also plays an important role. In ancient wars, gunpowder was an important weapon, and sulphur was one of the important ingredients of gunpowder. In the gunpowder formula, sulphur, saltpeter, and charcoal were mixed in a certain proportion, and after igniting, they could explode with great power. The gunpowder produced by this formula is used to make artillery, rockets and other weapons, and plays a huge role in < Br >
In the field of metallurgy, sulfur can be used as a reducing agent. During ore smelting, adding an appropriate amount of sulfur can reduce the metal oxides in the ore to metal elements, thereby improving the efficiency and purity of metal extraction.
Sulfur has indispensable applications in alchemy, medicine, military, metallurgy and many other fields, and has a profound impact on the development of ancient society.

Looking at the current market, the price of Panax notoginseng dansa often depends on the quality and the supply and demand of the market. However, roughly speaking, the price per catty may be between tens and hundreds of dollars. Those with high quality and urgent market demand, the price will necessarily increase; those with flat quality and more supply and less demand, the price will be slightly lower.
As for the second-class leech, the price is not constant. Generally speaking, the price per catty is also about tens to hundreds of dollars. The origin of the leech is different, and the difficulty of catching is different, all of which are related to the price. If the product is rich and easy to catch, the price will be slightly cheaper; if the product is rare, it will be difficult to catch, and the price will increase. < Br >
The price of the city is like the water of the river, which is constantly changing and uncertain. The camp of merchants can only profit by observing the current situation and reviewing supply and demand. The price of these two, but the approximate number, the actual price depends on the actual situation of the city.