3-iodopyridine

The main purpose of title No. 3 is to make tools and create things, to explore the mysteries of nature, in order to achieve the purpose of studying the times of heaven and man, through the changes of ancient and modern times, and to use the world for the benefit of the world.
As recorded in "Tiangong Kaiwu", it is described in detail in all kinds of craftsmanship and technology. The scope involved is from astronomy, down to geography, China and personnel, covering agriculture and mulberry, hardware, ceramics, boats and cars, paper and ink and other industries. This content is not only remembered, but also investigated. It details the process of craftsmanship, the selection of raw materials, and the production and application of utensils.
As far as agriculture is concerned, remember the planting methods of five grains such as rice and wheat in detail, from seed selection, sowing, seedling raising, to field management and harvest. It is intended to make farmers understand the importance of planting, follow the season and soil strength, so as to increase the yield of five grains. This is the foundation of people's livelihood, so that the people can eat and the warehouses are enriched.
In industrial manufacturing, such as smelting, forging, etc., remember the smelting of metals, from the mining and refining of ore to the casting of tools. There are no inaccurate records of key links such as temperature and ingredients. The equipment made can be used in different scenarios of production and life, making labor easier and efficiency multiplied.
In ceramic firing, from clay excavation, washing, billet making, to kiln firing, all steps are explained. Porcelain is not only for daily use, but also a symbol of Chinese exquisite culture, which can be used for trade and dissemination of Chinese civilization.
To sum up, the main purpose of title 3 is to use detailed records to inherit skills and spread knowledge, so that future generations can follow this, promote production development and civilization progress, and contribute greatly to the national economy, people's livelihood and cultural inheritance.

3-Incense sticks, its physical rationality can be studied.
Incense sticks are mostly made of wood flour, spices and other materials mixed together. On the shape of the stick, it is often used to make the stick. This shape is convenient for hand-held burning, and can maintain the quality of the burn. Its shortness and thickness are different, and the one that is small can be sized, and the one that is short is not small; the one that is thick is like the little finger, and the one that is thick is like the one that is small.
As far as the earth is concerned, the earth is thick, so that it can be burned in the fire, so that the fire can spread, and the effect of slow burning can be maintained. If the earth is hard, it will burn, or burn.
The density of the incense stick has also been studied. It can neither cause the burning speed to be sparse, nor can it hinder the burning. The appropriate density can ensure that the incense can be evenly and evenly released during the burning process.
In addition, the burning characteristics of the incense stick are particularly important. Its burning speed, the flame needs to be determined, and it should not be caused by burning, nor should it be strong. And the burning speed is slow and uniform, so that the burning speed can be measured by the burning speed. The ancient times also used this as an engraving test.
And the burning of the raw material, or the light, and the work of the materials used. A good incense stick is fragrant, gentle, and accompanied by a pleasant fragrance. It diffuses in the air, or is quiet and elegant, or is rich and mellow, and can create different atmospheres, or is beautiful, or leisurely and tranquil.
As for its weight, it varies depending on the size and materials used. The one with the best incense is one gram, and the heavier one can be ten grams. In addition, the physical rationality of the 3-gram incense, such as its shape, location, density, burning characteristics and even weight, are closely related to its use and people's use.

The combination of mortise and tenon has various methods and is very delicate. It is the essence of traditional Chinese construction. There are probably the following methods of combination.
One is the "lattice angle tenon". This is to cut the end of the wood obliquely to make a 45-degree angle, splice it in pairs, the corners are tightly fitted, the appearance is flat, and the lines are smooth. It is mostly used for the combination of the corners of the frame, such as the frame of cabinets, tables and chairs. The system needs to be accurately measured and cut correctly, so that it can fit seamlessly, strong and beautiful.
The second is the "dovetail". Its shape is like a dovetail, the tenon and mortise are trapezoidal, one end is wide and the other is narrow. This tenon is tightly bitten and difficult to disengage. It is mostly used for connecting boxes, drawers and other components. Because of its unique shape, it can withstand a large tensile force, making the structure stable. It is not easy to loosen after years, just like the combination of the two sides of the drawer and the back wall today. It depends on this tenon.
The third is the "dumpling-corner tenon". The three square materials are combined in one place, just like the corners of a zongzi. The tenon and the tenon of the three materials cooperate with each other, and the angle is accurate, intersecting at 120 degrees. It is often used in the corners of furniture, such as tables and cabinets, to build a regular and solid frame, reflecting the unique beauty and stable structure.
The fourth is the "shoulder tenon". At the joint of the leg foot and the tooth plate, the inclined shoulder is cut out, and the tooth plate is also beveled accordingly. The two are inserted into each other, and then fixed with tenon and mortise. This tenon method makes the tooth plate and the leg foot transition natural, enhances the overall stability and aesthetics of the furniture, and is common in all kinds of table cases. It is a common method for traditional furniture production.
In addition, there is a "horse pin", which is a detachable tenon and tenon structure. It is mostly used for the connection of detachable furniture parts, which is easy to transport and assemble. The tenon and mortise are cleverly designed, pushed in during installation, stable during use, and can be relatively easily removed when disassembled.
The methods of tenon and mortise all contain the wisdom of the ancients. They skillfully combine wood with exquisite skills, without the need for riveting, but they achieve sturdy, durable and beautiful utensils and buildings, which have been passed down for thousands of years and shine brightly.

Equipment is stored and lost, so many people should pay attention to it. When it is stored, the environment is the first priority. Moderate dryness, and it cannot cause moisture, otherwise rust is easy to occur, and its precision is damaged, and the effectiveness of the equipment is greatly reduced. And it is placed in an orderly manner, and it is distinguished by type, so that it is easy to find and take, so as to avoid panic and misuse. It also takes time to check and check to see if there are any abnormal conditions. Small defects are repaired early, so as not to cause major trouble.
As for the time of transportation, stability is the most important thing. On the road of driving, choose a flat one to avoid bumps. If the equipment is damaged by earthquakes, it will fall short. And add protective equipment, cotton felt soft material lining the surrounding area, to slow down and prevent collisions. The escort must also be cautious and focused, and not slack off. The wind and rain on the way should also be guarded against, so as not to let the equipment get wet.
Furthermore, when handing over, check it in detail. The number and quality of the quality must be clear. If there is a difference, it should be investigated immediately, and no future troubles should be left. Although the storage and loss of equipment are common, it is of great significance. A little carelessness can cause a lot of harm, and it must be done with caution to ensure that it is safe.

3% of the total, the impact of human health on the environment, let me explain.
In terms of environment, if these substances flow into natural water, or aquatic organisms become powerful. The components of the body or the physiology of aquatic organisms can influence their reproduction, production and transportation. For example, the retention of certain substances can make the reproductive system normal, resulting in a decrease in reproduction rate and disruption of aquatic biological balance. If the soil is initiated by rain, etc., or the soil microbial community is changed, the soil fertility and material circulation are affected. Microorganisms are an important component of the soil biological system, and their community is transformed or affected by plant life, so that the vegetation is affected, and the impact of the whole biological system is characterized.
When it comes to human health, 3% of it may have a therapeutic effect under a certain amount, and it is very harmful to use it or use it. If this substance is exposed in the early stage, it may cause resistance. If the bacteria are exposed to the substance, some people with anti-gene can survive, and they do not multiply, so that the sensitivity of the bacteria to the substance is reduced, and the degree of disease treatment is increased in the day. In addition, the substance is left in the human body, or the normal physiological function of the human body is affected. Such as affecting the secretion system, causing hormone imbalance, such as thyroid gland function, reproductive system diseases, etc. It may also cause damage to important organs such as the liver, because it is excreted on behalf of the body, and the amount of material is left to aggravate the organ. In the past, organ function declined.
Therefore, 3% of the people in the environment are affected by the depth of health, use it with caution, and add a tube to reduce its adverse effects, improve health and people's well-being.