pyridine, 3,4,5-trifluoro-

Ask him: "Three, four, and five - the Three Gorges - what is the material reason?"
He said: "The number of three, four, and five is also the number of jokers, and the number of jokers is also the number of four strings and five strings. This is a wonderful principle of geometry. As for the Three Gorges, its physical properties are determined by the terrain where it is located. In the land of the Three Gorges, the mountains are sandwiched, and the rivers are surging. The river water is fluid, fluid, can carry boats, and has pressure. It exerts force on things such as dams. Its water temperature is subject to changes in seasons and climate. It is slightly warmer in summer and slightly colder in winter. And the water flow rate varies according to the width of the terrain. The flow rate at the narrow gorge is rapid, and the flow rate at the width of the gorge is slow. The rocks of the Three Gorges are solid, hard in texture, eroded over time, and have different shapes. The mountains contain various minerals, either raw metals or the essence of stone. The wind between the gorges is a gas, flowing with the wind direction and the terrain, slow or fast, interacting with rivers, mountains and rocks, forming a unique physical scene of the Three Gorges. "

3,4,5-triazine is a class of nitrogen-containing heterocyclic compounds with unique chemical properties. Its ring structure consists of three carbon atoms and three nitrogen atoms alternately arranged to form a six-membered ring.
First of all, 3,4,5-triazine has a relatively hot topic stability. Because of the formation of a conjugated system between nitrogen atoms and carbon atoms in the ring, the molecular structure is stable and can withstand a certain high temperature without easy decomposition. This property makes it potential for material applications in high temperature environments, such as the preparation of high temperature resistant engineering plastics, fireproof materials, etc., which can maintain its own structure and properties in high temperature scenarios.
Secondly, the compound is alkaline. The nitrogen atom in the ring contains lone pairs of electrons, which can accept protons and exhibit alkalinity. This alkalinity allows it to react with acids to generate corresponding salts. In the field of organic synthesis, it is often used as a base catalyst to participate in many chemical reactions and promote the reaction.
Furthermore, 3,4,5-triazines have certain reactivity. Due to the distribution of electron clouds on the ring, nucleophilic substitution reactions can occur. For example, when a suitable leaving group is connected to the ring, nucleophilic reagents easily attack the carbon atoms on the ring, replace the leaving group, and form new organic compounds. This provides the possibility for the synthesis of a variety of nitrogen-containing derivatives, which is of great significance in the fields of medicinal chemistry and materials science.
In addition, 3,4,5-triazines also have certain coordination capabilities. The lone pair electrons of the nitrogen atom can form coordination bonds with metal ions to form metal complexes. Such complexes often have unique physical and chemical properties and have potential applications in catalysis, luminescent materials, etc.
In short, 3,4,5-triazine has important value and wide application prospects in many fields due to its own structural characteristics, such as thermal stability, alkalinity, reactivity and coordination ability.

3, 4, and 5 are also the number of joists. It has a great function in all matters of water conservancy. "Kaogong Ji" says: "The craftsmen built the country, and the water and land were based on the county." When controlling water, if you want to know the height of the terrain, you can use this number to create a moment to measure the level.
The way to control water, the blockage of ditches, and the repair of embankments all depend on accurate measurement. With 3, 4, and 5 as degrees, the device for making right angles can be used to determine the vertical and horizontal. Dredging the river, measuring its depth and width, and planning the way to dredge according to this. When building an embankment, use this to determine the correctness of its foundation, so that the embankment is stable and resists floods.
In the method of irrigation, if you want to use canal water to irrigate the fields, you need to know the height difference of the fields. Use the method of 3, 4, and 5 to clarify the topography, make the water flow smooth, and even the fields.
As for the river course for sailing, to ensure that it is straight and shallow, you also need to use this number. Measure its width and narrow, determine the distance between the two banks; measure its depth, and ensure that the ships are navigable.
In the case of hydraulic engineering, the numbers 3, 4, and 5 are the basis for measurement and planning. They are related to the success or failure of water conservancy projects, so that the water can be governed and used by the people.

If you want to know the synthesis method of "3, 4, 5 - Yangtze River -", I will describe it in detail.
The number of joking shares is also the number of joking shares, and the wise men of ancient times have long observed it. "Zhou Bi Sutra" says: "Hook three strands, four strings and five strings", this is the fixed ratio of the three sides of a right-angled triangle.
As for the "Yangtze River", it is the giant river of China. It has a long history and is related to the lifeblood of the country and people's livelihood.
If you want to combine this number with the "Yangtze River", one method can be considered from the perspective of geographical surveying and mapping. If you take the number of hooks as a scale, on the bank of the Yangtze River, with precise instruments, according to the ratio of 3, 4, and 5, you can measure the land map, which can show the twists and turns of the river bank and the height of the terrain. Because of the number of hooks, you can fix the right angle, help the surveyor to plan accurately, and clarify the shape of mountains and rivers.
Or from the perspective of engineering construction. On the Yangtze River, the construction of bridges and dams requires accurate measurement and design. With 3, 4, and 5 as the base, the proportion of the structure can be determined, so that the project is stable. For example, when building a bridge, the construction of the bridge foundation and the arc of the bridge arch can be used to make its bearing capacity and stability reach a good state, and it is in line with the characteristics of the river's flow and topography.
Furthermore, think about it from the way of combining cultural symbols. 3, 4, and 5 have their own meanings in ancient culture. 3 often represents the heaven and the earth, 4 resembles the four seasons, and 5 contains the five elements. The Yangtze River is the source of civilization, and combining this number with it can give more cultural connotations to the Yangtze River. For example, taking 3 as the upper, middle, and lower sections of the river, using 4 to represent the scenery changes of the Yangtze River during the four seasons, and using 5 to match the five elements to view the ecological circulation of the Yangtze River. In this way, the number and the river are combined, and the cultural image is blended, which also becomes a unique synthesis method.
All these numbers can be regarded as the synthesis method of "3, 4, 5 - Yangtze River -", each with its own reasons, and can be used according to local conditions.

I look at your question, but I am inquiring about the application of 3, 4, and 5 - the Three Gorges - in what field. The references to 3, 4, and 5 are not clear, but the Three Gorges can be discussed from the fields of water conservancy, energy, and transportation.
In the field of water conservancy, the Three Gorges Project is of great use in flood control. Its dam is towering and the storage capacity is huge, which can stop flood water and control downstream flow. During the flood season, the river water is surging, and the Three Gorges can accommodate the flood and slow down its trend, so that the middle and lower reaches of the river are protected from floods, and the safety of all people and the safety of the fields and acres is guaranteed. If the river flooded in the past, and the lives along the coast were devastated, now there are the Three Gorges, and the flood is greatly reduced.
In terms of energy, the Three Gorges is the hydropower station of the world's giants. Its turbines rotate, turning water energy into electricity, which is transported to all directions. This electricity is widely used for industry, people's livelihood, and promoting economic prosperity. And the production of clean energy meets the needs of today's environmental protection, reduces the consumption of fossil fuels, reduces the harm of pollution, and benefits future generations.
In the field of transportation, the Three Gorges improves the waterway of the Yangtze River. The dam raises the water level, the dangerous beach is submerged under water, and the waterway becomes wider and deeper. Ships pass more smoothly, going up to Sichuan and Shu, and reaching Wuyue. Goods flow smoothly, and commerce is prosperous. In the past, the road to Shu was difficult, but the waterway was also dangerous. Today, the boat is convenient, promoting regional exchanges and economic exchange.
In addition, in the field of tourism, the scenery of the Three Gorges is fascinating. The scenery of the High Gorge and the flat lake attracts tourists from all over the world. The blend of cultural monuments and natural beauty adds luster to tourism, drives the local tourism economy, and increases people's livelihood.
Although 3, 4, and 5 are not specified in detail, the Three Gorges have made great contributions in the fields of water conservancy, energy, transportation, and tourism. It is the well-being of the land of China. In future generations, it should be well used and protected to make it profitable for generations.