pyrrolo[b]pyridine

Boron and its compounds [b] of boron, its chemical structure is unique. The atomic number of boron is 5, and it is in the second cycle group III A of the periodic table of elements. Its nucleus contains 5 protons, and the extrinuclear electrons are arranged in two layers, the first layer has 2 electrons, and the second layer has 3 electrons.
Boron elements have a variety of allotropes, common ones are amorphous boron and crystalline boron. Amorphous boron is brown powder, while crystalline boron has a hard state and a certain luster.
In terms of compounds, boron is often + 3 valent. Take boron trioxide as an example, it is a colorless glassy crystal or powder, which has the properties of acidic oxides and can react with bases to form borates. Another example is sodium borohydride, which is a strong reducing agent, in which boron forms a specific chemical bond with hydrogen, and boron atoms are connected to four hydrogen atoms in a covalent bond to form a tetrahedral structure.
Looking at boric acid again, it is a white crystalline powder. In its structure, boron atoms are connected to three hydroxyl groups, and the central boron atoms are hybridized with sp ², showing a planar triangular structure. Boric acid in water does not directly ionize hydrogen ions, but interacts with water molecules to accept hydroxide ions, making the solution acidic.
Boron compounds are widely used in many fields. In materials science, boron fiber reinforced composites have high strength and low density due to boron structural characteristics; in the metallurgical industry, borides such as iron can optimize metal properties. Due to the unique chemical structure of boron, its compounds exhibit diverse and excellent properties.

Good, if you have something to trust, you should tell it to the truth. Common things have many physical properties. Take gold and stone as an example, it is strong and hard, and can bear weight and pressure without breaking, and the resistance of this force is also. Like a rock, it has been eroded by wind and rain, and the years have passed. Its shape has not changed, because its internal structure is tight and the attractive force between atoms is strong.
Also watching water and fire, water is soft and good to flow, and things revolve around, and follow the trend. It is fluid and can change according to the shape of the container. If you put water on a round vessel, it will be round, and a square vessel will be square. However, water can also carry a boat or overturn it, which is related to the effect of force. When water rushes with a turbulent trend, its contained energy can destroy embankments and destroy houses, which shows the enormity of its energy.
Fire is bright and hot, and can burn all things. Its essence is a violent oxidation process, releasing a lot of heat energy. Fuelwood turns to ashes when it encounters fire, which is the image of chemical energy converted into heat energy. The heat of fire can cook grains, melt gold and stone, and has a wide range of uses.
As for wood, it is light and elastic. In its texture, it hides the wonders of nature. Wood can be used as a material to make boats and carts, because it can float in water and has toughness, it can withstand certain deformation and continuous deformation. Wood is also flammable, and it is the capital of fire. This is its energy transformation property.
Let's talk about qi again. Although it is invisible and colorless, its power can be felt. When the wind is blowing, the movement of qi is also. The breeze blows on the face, gentle and comfortable; when the wind is angry, it pulls up trees and falls down. Qi can be compressed, and in a closed device, the pressure increases gradually. It can be used as a power, such as the power of steam, which can drive the operation of machinery. This is the physical property of qi.
All these things in the world have physical properties, whether hard or soft, hot or cold, or dynamic or static. Each has its own reason. You need to carefully observe it before you can understand its secrets.

What I see you asking is to ask Boya and [b], and ask what field it has application. Boya is also a good drummer in spring and autumn. His piano skills are extraordinary. In the field of music, it can be said that he has far-reaching influence, and the application is also reflected.
In the past, Boya drummed the piano, and his ambition was in the mountains. In the Zhong Zi period, he said: "Good, Ee Xi is like Mount Tai!" The ambition was in the flowing water, and the Zhong Zi period said: "Good, the ocean is like a river!" Therefore, in the field of expressing emotion, Boya's piano skills can convey the mind with the sound of the piano, which makes the listener feel the same. The sound of the piano can express ambition and pride, and can also express delicate feelings, so that the person who hears it can feel like they are there. This is the application of music art in emotional transmission.
Furthermore, Bo Ya and Zhong Ziqi intersected with the sound of the piano, achieving bosom friends and good stories, which have been passed down through the ages. This is reflected in the field of interpersonal communication, where music can serve as a link, connect the soul, and make people who have never met each other know and cherish each other because of resonance.
In the field of cultural inheritance, the matter of Bo Ya has been passed down by future generations and has become a cultural symbol. Many artistic creations such as poems, songs, and paintings often quote the allusions of Bo Ya, enriching the cultural connotation and inheriting the cultural spirit, so that future generations can get a glimpse of the elegant taste and profound friendship of the ancients.
And music can cultivate the temperament, and Bo Ya's piano skills should also make a difference in the field of personal cultivation and improvement. Playing the piano and playing the strings can clear the mind, cultivate the self, and make people find inner peace in the hustle and bustle of the world.
It can be seen that Boya's piano skills and related stories have important applications and far-reaching significance in many fields such as emotional expression, interpersonal communication, cultural inheritance, and personal cultivation.

The bow and crossbow are combined [b], and there are many ways to combine them. As described in "Tiangong Kaiwu", the production of the bow and crossbow is quite exquisite, which is related to the selection of materials and craftsmanship.
First of all, the material of the bow needs to be straight and straight wood, which is tough in nature. This is the backbone of the bow. And take horns, preferably from northern horns, which are strong in nature and can increase the elasticity of the bow. The tendons are also important, and more beef tendons are taken, which are carefully processed to make them flexible and strong. Glue is boiled with a fish swim bladder, which has excellent viscosity and is used to bond the various materials.
As for the production process, the first heavy bow stem is made. The selected wood is cut and formed according to the size, and repeatedly dried and baked to remove its moisture, so that it is firm and does not deform. For the second loading of horns, glue the horns firmly to both ends of the bow stem, and be sure to fit tightly without the slightest gap. Then bind the tendons, and wrap the treated beef tendons tightly around the bow stem to enhance its toughness and tensile force.
The production of the crossbow is the most critical. It is made of fine iron, with accurate size and clever fit of each part. The crossbow arm is made of solid wood, polished and smooth, which is easy to hold and aim. The crossbow string also needs high-quality materials, such as silk thread and beef tendon twisted, which are tough and durable, and can be powerful.
And when making crossbows, craftsmen need to be in awe, fine operation, and a trace of error will affect the performance of the crossbow. Or insufficient power, or short service life. Therefore, those who are good at making crossbows in ancient times are all skilled craftsmen. With exquisite skills, they have become a weapon for killing the enemy. The combined method is actually the crystallization of the wisdom and experience of the ancients.

Let's talk about that Xianggao, one day I thought about it, how is the market situation at home? I was bored, so I paced around the house and thought.

The city is bustling, people come and go, all running for profit. Merchants gather, and the colonies are complex. Looking at the streets, there are many shops and signboards. There are those who sell silk and satin, which are gorgeous in color and smooth in tentacles, and rich families often come to buy them to decorate themselves; there are also those who sell firewood, rice, oil and salt, which is a necessity for people's livelihood. No matter rich or poor, they are indispensable, and there is an endless stream of customers every day.
However, there is no shortage of chaos in the city. There are those who are cunning, who are shoddy and deceive customers. Or short catties, making ill-gotten money. And the city officials sometimes fail to supervise, resulting in such evil deeds happening from time to time.
Looking at the merchants, the competition is fierce. In order to make a profit, or to lower prices to attract customers; or to brag about the goods. However, there are also honest business people who win praise from everyone by virtue of real materials and high-quality service, and the business is prosperous.
Look around the city again, there is a hustle and bustle of carriages and horses. Goods from afar are constantly being shipped, and there are local specialties, which are shipped everywhere. The prosperity of the city is related to the livelihood of everyone, and it can also be seen that one side rises and falls.
However, in this busy market situation, people are easily fascinated. Xiang Gao knows that if you want to gain a foothold in the city, you need to stick to your heart, not be confused by chaos, and be based on integrity in order to make a difference.