Pyridine, 3-fluoro- (8CI)(9CI)

The physical nature of the direction of rivers (8CI) (9CI) is related to the characteristics of the direction of water flow. The direction of water flow is influenced by many natural factors.
The height of the terrain is its key influence. The potential of the earth, if the high and steep place is inclined to the low-lying place, the water will flow along this drop, just like the water from the high place running to the valley and plain, this is the common sense of water flowing to the low place. For example, the Yellow River, originating in the northern foothills of Bayan Kara Mountain on the Qinghai-Tibet Plateau, flows into the Bohai Sea from west to east, passing through several provinces. Due to the towering terrain in the west, the terrain in the east is gradually decreasing.
The direction of the mountains also plays an important role in it. Mountains are like natural barriers, blocking the path of water flow. Water flows through low-lying places such as mountains, or detours, or looks for valleys. Such as Hengduan Mountains, its north-south direction, many rivers move along this mountain range, parallel north-south, forming a unique water system pattern.
Climate factors cannot be ignored. The amount of precipitation determines the abundance of water sources. In places with abundant rainfall, rivers have sufficient water and stable flow. In arid regions, rivers or water sources are scarce, or flow intermittently. For example, in tropical rainforest areas, precipitation is frequent, river networks are dense, and water flows are continuous all year round; rivers on the edge of deserts often dry up seasonally due to less precipitation.
In addition, the earth's rotation generates a ground rotation deflection force, although invisible but powerful. In the Northern Hemisphere, the right bank of rivers is initialized strongly, and the left bank is piled up more; in the Southern Hemisphere, the opposite is true. This force affects the shape of the river and the micro-direction of the water flow, and changes the direction of the local water flow under long-term action.
The physical properties of rivers are the result of the intertwining and joint shaping of various natural forces, which have a profound impact on ecology, geographical landscape and human activities.

Mercury, or mercury, is a liquid metal with many unique chemical properties.
Mercury (8CI) (9CI) is a liquid at room temperature, resembling flowing silver, which is its significant physical property and also affects its chemical behavior. Mercury has relatively stable chemical properties and is not easy to combine directly with oxygen at room temperature and pressure. When heated to a specific temperature, mercury reacts with oxygen to form mercury oxide, just like "mercury meets fire and gradually turns into a red powder". This powder is mercury oxide.
Mercury can form amalgam with a variety of metals, such as gold and silver. Taking gold as an example, gold is placed in mercury, and the two fuse with each other to form a gold amalgam. This process is like "gold enters mercury and quietly assimilates". Gold amalgam is widely used in metallurgy and other fields, and is often used to extract metals such as gold.
Mercury also has certain toxicity, and its compounds are also toxic. In ancient times, although the understanding of mercury toxicity was not as detailed as it is today, there were many cases warning of its harm. For example, when alchemists were refining alchemy, due to long-term exposure to mercury and mercury-containing substances, poisoning occurred from time to time. The so-called "Dan contains mercury, and long-term use hurts the body" is the ancient people's preliminary understanding of mercury toxicity.
In addition, mercury is highly volatile and will evaporate into mercury vapor at room temperature. Mercury vapor is also toxic, which makes it necessary to be extra cautious when handling mercury-related substances to avoid poisoning due to inhalation of mercury vapor. "Mercury is invisible, and it is dangerous to enter the body." Although the ancients did not know the specific principle, they had already realized its danger.

"Tiangong Kaiwu" says: "Lu (8 inches) (9 inches) of silk, what is its main use?"
Lu silk, which is produced in Luzhou, Shanxi Province, has a wide range of uses. The first one to bear the brunt can be the best choice for clothing production. In ancient times, dignitaries, scholars and scholars all wore Lu silk clothes as a symbol of fashion and status. Lu silk is soft and smooth in texture and has an excellent touch. It is not only comfortable to wear when made into clothes, but also its color is gorgeous, the pattern is exquisite, and it has high aesthetic value. For example, the royal clothes of officials are made of Lu silk, which is more solemn and majestic; and the regular clothes of rich people can also add a bit of elegance and grandeur.
Furthermore, silk is also commonly used in interior decoration. Because of its fine texture, it can be made into curtains, curtains, etc. In the living room, the silk curtains are soft and elegant, which can not only create a warm and romantic atmosphere, but also play a certain role in shading and privacy. The curtains made of silk are gently swayed in the wind, adding a smart beauty to the interior space, and can also reflect the taste and style of the owner.
In addition, silk also plays an important role in ceremonial gifts. At various festivals and festive events, silk is often chosen as a precious gift. Its exquisite quality and unique cultural connotation express the deep affection and good wishes of the giver, and the recipient can also feel respect and care from the silk. In short, the silk plays an important role in many aspects such as clothing, decoration and etiquette, adding many colors to people's lives.

In "Tiangong Kaiwu", the art of papermaking is very delicate, and the paper of Lu (8 inches) and (9 inches) also has its unique method.
The paper made by Fu Lu is the first material to be selected. Mulberry skin and green skin are often selected as the top choices. The fibers of these two are flexible, and the paper is tough. When picking the skin, choose the good material and take it, remove its coarseness and keep its essence. When the leather is obtained, it is soaked in lime water slurry. This liquid can remove its impurities, rot its epidermis, and make the fibers easy to dissociate. Soak for many days, until the leather is soft and rotten moderately, remove it and rinse it with water, so that the traces of lime are completely removed, and the water is clean and the material is clean.
After that, the crushed material becomes a pulp. The pestle and mortar are used to pound, so that the leather material is turned into a delicate pulp, which is evenly dispersed in the water, just like a cloud floats floating. This measure is based on the experience of the craftsman. The thickness of the pulp is related to the quality of the paper.
Then use the bamboo curtain to copy the paper. The craftsman moves the curtain into the pulp, gently swings and slowly lifts it, so that the pulp is evenly attached to the curtain, and the water drains down. The method of making paper needs to be stable and accurate. The inclination of the curtain and the urgency of the speed all affect the thickness and evenness of the paper. Copy wet paper, layer by layer on the wooden board, add stone to press, squeeze out the residual water, and the paper gradually solidifies.
Then br >. In the "lane" drying room, use soil bricks to form a lane shape, with built-in char The wet paper is attached to the wall of the alley and dried slowly. The mastery of the heat is crucial. If the fire is fierce, the paper will be brittle, and if the fire is weak, it will not dry. The craftsman looks at the color of the paper and touches the paper, and adjusts the heat in a timely manner until the paper is dry and moist, and the paper is completed. Such various processes are interlinked, and they are all essential for the manufacture of Lu paper (8 inches) and (9 inches).

When storing and transporting the boat (8-foot boat) (9-foot boat), it is necessary to pay attention to all things mentioned in "Tiangong Kaiwu".
The storage of the boat, the first heavy hull protection. Wood is its main material, and it must be avoided in damp places to prevent decay. Place the boat in a high and dry place, and check the hull frequently. If there are signs of decay on the wooden board, it should be replaced in time. The gaps in the boat should be filled with tung oil lime, so as not to allow rainwater to penetrate and cause damage to the hull.
In addition, the rope, sail gear and other objects on the boat should also be properly placed. The rope should be rolled and hung in a dry and ventilated place to prevent mildew, moth-eaten, and damage to its strength. When storing the sails, they should also be stacked neatly, so that the folds are not damaged, and they should be protected from sunlight to prevent their material from aging.
As for the transportation of boats, first, it is necessary to carefully check the channel conditions. Know in advance the depth of the water level, the width of the river channel and whether there are any dangerous obstacles such as reefs and shoals. In case of low water level, it is necessary to prevent the bottom of the boat from hitting a reef; in narrow river channels, be careful to sail the boat to avoid collisions with other boats.
Second, reasonably distribute the goods. According to the carrying capacity of the ship, distribute the goods evenly, and do not make one side of the hull too heavy, resulting in unstable navigation. And put the heavy cargo on the bottom and the light cargo on the top to keep the center of gravity of the ship stable.
Third, pay attention to weather changes. Heavy rain, strong winds and other bad weather are extremely unfavorable for sailing on the boat. Check the weather carefully before the trip. If the wind and rain are approaching, when the speed is to find a safe harbor to berth and avoid, do not rush forward.
Fourth, during the voyage, the cooperation of the boatmen is also crucial. The helmsman is in charge of the course, and the sailors perform their duties, such as lifting the sails, setting the sails, supporting the poles, etc., and cooperate tacitly to ensure the safety and smooth completion of the transportation of the boat.