7-Bromoisoquinoline

Radium, as a matter, has physical properties different from ordinary things.
Radium emits a strange light, its light is faint and bright, and it can shine in the dark room without pretending to be external light. This light is unlike ordinary light, which can penetrate through thin objects. If radium is placed behind paper, its light can be reflected outside the paper, and it can make the negative of photography sensitive to light, as if it has a mysterious penetrating power.
And radium is radioactive, which is its unique property. Its radiation energy can ionize the nearby air, causing the air to be electrically conductive. Long-term exposure to radium radiation can hurt people's skin and harm people's health, which is also powerful.
In addition, radium also shows an abnormal state in terms of heating. Even if the ambient temperature is constant, radium itself can generate heat, and the generated heat is continuous, which is very different from all things that require external heating.
Although the mass of radium is small, it contains a lot of energy. According to physics, the source of its energy is deep within the atom. Although its body is small, its energy is huge. If it can be used properly, it will bring endless benefits to the world, or it will cause serious trouble due to ignorance of moderation. This should be considered carefully and discerned. The various physical properties of radium that are different from ordinary things make it have extraordinary potential and value in various fields, and also make the world both in awe of it and full of enthusiasm for inquiry.

Mercury is light, because the characteristics of mercury are generated and transformed by light. Mercury, an ancient water element, is often liquid in the atmosphere, and has general chemical properties.
One of its chemical properties is its original nature. In case of oxidation, it is easy to be oxidized. Take the reverse reaction of mercury and oxygen as an example. In addition, mercury can be oxidized and synthesized to form mercury oxide. In this reaction, mercury loses its original nature.
Mercury can also form alloys of gold and mercury. This property makes it useful in many fields such as metallurgy. In the past, gold extraction, often through the characteristics of mercury-gold formation, enriched gold from rock.
Furthermore, mercury compounds also have characteristics. Such as mercury chloride, which is toxic, but can play a catalytic role in specific chemical reactions. Mercury sulfide, color, and vulgar sand are not important chemical materials, but also commonly used in chemical materials.
Under the action of light, the chemical properties of mercury may be subtle. Light energy can stimulate the outer molecules of mercury atoms, causing its activity to change, and affecting the rate and direction of mercury chemical reactions.
Mercury photochemical properties, due to light, show chemical reactions. The characteristics of itself and compounds are important in many fields. However, due to its toxicity, the use of chemical properties should be cautious.

Those who combine mercury with light, there are three common methods.
One is to use the sand of Dan. In the sand of Dan, the source of mercury is also. First of all, the sand of Dan, the crushed and the end, put in the crucible. Calcined with a fierce fire of charcoal, the sand of Dan is subjected to the pressure, in which the mercury rises, and it is collected by a condenser. When the mercury is cold, the mercury is removed from the liquid. This is a common method used in ancient times. "Baopuzi": "The formation of water from the sand of Dan." The reason is here.
Second, use the Reverse to obtain, Liquid and then extract mercury., Sulfuric acid pentahydrate also. Take the liquid and dissolve it in water, put it in it, and it can be dissolved. On the contrary, it is said: "Enter the water, and come out of the liquid." When it comes out, the liquid still contains mercury and so on. By the method of sinking and soaking, remove the bulk material, and then steam it to separate the mercury. The boiling temperature of mercury is low, and it is easy to separate.
Third, use the amalgamation method. In the mercury-containing stone, mercury is added. Mercury can form mercury in the gold and other gold in the stone, and it can also adhere to mercury. In addition, the mercury is divided into the stone, and then by the method of steaming, the mercury is released from the mercury, condensed and recovered. This is due to the compatibility of mercury and gold, and it is also commonly used in ancient gold panning and other operations, which can enrich mercury and other gold in mercury.
All such methods are based on the characteristics of mercury, or chemical reaction, or physical separation, in order to obtain mercury. However, if mercury is toxic, it must be carefully operated to prevent its escape to avoid damage.

7 - Erbium-doped fiber lasers have extraordinary applications in many fields. In the field of communication, it is a key gain medium. In today's information age, the amount of data is surging like a torrent, and the signal transmission loss in long-distance fiber optic communication systems is considerable. With its unique spectral characteristics, erbium-doped fiber lasers achieve high-efficiency optical amplification near 1550nm, greatly extending the signal transmission distance, improving the communication capacity, and ensuring the fast and stable transmission of massive data around the world, just like adding a powerful engine to the information highway.
In the medical field, it also has excellent performance. Because it can generate a specific wavelength laser, this laser can interact with biological tissues in a specific manner. If used in laser surgery, it can accurately cut diseased tissue while causing minimal damage to surrounding normal tissue, just like a delicate scalpel, helping doctors to perform surgeries more efficiently and safely, relieving pain for patients and accelerating the recovery process.
In the field of sensing, it also plays an important role. Using its sensitive characteristics to environmental factors, such as temperature, stress changes, etc. will cause changes in laser output characteristics, a sensing system can be built to accurately perceive small changes in the outside world. It can be applied to large-scale building structure health monitoring to detect potential safety hazards in the structure in time; it can also be used for infrastructure monitoring such as oil pipelines and power cables to ensure their stable operation, just like keen "sensing antennae" to protect infrastructure safety.
In the field of industrial processing, erbium-doped fiber lasers are also indispensable. Its high-energy density laser beam can achieve fine processing of a variety of materials, such as cutting, welding, punching, etc. Compared with traditional processing methods, it has the advantages of high precision, fast speed, and small heat-affected zone. It is widely used in high-end manufacturing industries such as aerospace and automobile manufacturing, injecting strong impetus into manufacturing process innovation and promoting the development of the industry towards high precision and high quality.

In today's world, those who are icy and bright in the city have a fixed quality. The icy and square light, the workmanship of its production, the quality of its materials, and the quality of its products, can all make a difference.
If the craftsman's skills are meager, and the craftsman's skills are meager, and the effort is expended, the price will be high; those who are rough, the merit is not enough, and the price is low. Such as the icy and square light of good craftsmanship, the flow of the flow, the shape is lifelike, comparable to beautiful jade, the market or even a hundred gold or even a thousand gold; while the mediocre factory has many flaws, its value may be ten gold.
In terms of materials, it is rare to use rare materials, such as the wonders of the cold region, the crystals of the deep sea, etc., which are integrated into the ice and square light, and the price is high; if it is based on ordinary materials, the price is high. If you take the ice and square light made by the cold region, because of the quality of the materials, the market price may exceed a thousand gold; if you use ordinary crystal jade materials, you may need a hundred gold up and down.
It is also a high-quality product. High-grade ice and square light can lead the world and help people practice, and they are often in high positions, with more than a thousand gold; low-grade ones have little utility, or are worth ten gold.
Of course, ice and square light are in the city, and the price ranges from ten gold to more than a thousand gold. Only by measuring the factors of its workmanship, materials, and products can it be obtained.