Excellent Reading Feelings of Science Explorers

After reading a book, I believe you must have a lot to share. You might as well sit down and write your feelings. Maybe you have no clue now. The following is a collection of excellent reading impressions of science explorers. You are welcome to use them for reference. I hope it will be helpful to you.

The body can attract materials such as steel. Its two ends have the strongest ability to attract steel. These two parts are called magnetic poles. A magnet that can rotate on its own, such as a magnetic needle suspended here. When the magnet is stationary, the magnetic pole that guides it is called the South Pole, also called the S pole; The magnetic pole pointing to the north is called the North Pole, also called the N pole. The magnetic poles of the same name attract each other, and the magnetic poles of the same name repel each other. The property of magnets attracting iron, cobalt, nickel and other substances is called magnetism. The area with strong magnetism at both ends of the magnet is called the magnetic pole. One end of the magnet is called the North Pole (also called the N pole because the initial letter of the English North is N), and the other end is called the South Pole (also called the S pole because the initial letter of the English South is S). Experiments show that the same magnetic poles repel each other and the opposite magnetic poles attract each other.

There are many protomagnets with two opposite magnetic poles in iron. When there is no external magnetic field, these protomagnets are in disorder, and their magnetism counteracts each other, so they do not show magnetism. When the iron is close to the magnet, these primary magnets are orderly arranged under the action of the magnet, so that the end close to the magnet has polarity opposite to the polarity of the magnet and attracts each other. This shows that the iron can be magnetized by the magnet due to the existence of the primary magnet. However, copper, aluminum and other metals have no original magnet structure, so they cannot be attracted by magnets.

What is magnetism? In short, magnetism refers to the effect of magnetic force on materials placed in an uneven magnetic field. In the same non-uniform magnetic field, the magnetic direction and intensity of the unit mass of the material determine the strength of the material's magnetism. Because any substance has magnetism, any substance will be affected by magnetic force in the uneven magnetic field.

What really exists in the space around the magnetic pole is not a magnetic line of force, but a kind of field. The mutual attraction of what we call ferromagnetic materials is carried out through the magnetic field. We know that there is universal gravitation between substances. It is a kind of gravitational constant magnetic field similar to it. It is a kind of constant magnetic field that is full of the space around the magnetic pole. The strength can be expressed by the number of imaginary magnetic lines of force. The magnetic field is strong where the magnetic lines are dense, and weak where the magnetic lines are sparse. The number of magnetic lines of force passing through a unit section is called magnetic flux density.

A moving charged particle will be subjected to a Lorentz force in the magnetic field. The strength of the magnetic field is determined by the size of the Loren magnetic force that the same charged particle receives in different magnetic fields. Tesla is the SI unit of magnetic flux density. The magnetic flux density is the basic physical quantity to describe the magnetic field, while the magnetic field intensity is the auxiliary quantity to describe the magnetic field. Tesla, N (1886~1943) was an American electrical engineer of Croatian origin who invented transformers and AC motors.

The magnetism of matter is not only universal, but also diverse, and therefore has been widely studied and applied. From our body and the surrounding materials, to various stars and interstellar materials, atoms, nuclei and elementary particles in the micro world, and various materials in the macro world, all have this or that kind of magnetism.

How many kinds of magnetism are there in the world? Generally speaking, the magnetism of materials can be divided into weak magnetism and strong magnetism. According to the different characteristics of magnetism, weak magnetism can be divided into diamagnetism, paramagnetism and antiferromagnetism, while strong magnetism can be divided into ferromagnetism and ferromagnetism. These are the magnetic properties produced by the electrons in the atoms of macroscopic materials, and the atomic nuclei in the atoms also have magnetic properties, which are called nuclear magnetism. But the nuclear magnetism is only about one thousandth or less of the electronic magnetism, so generally speaking, the material magnetism and atomic magnetism mainly consider the electronic magnetism in atoms. The low magnetism of atomic nucleus is due to the fact that the mass of atomic nucleus is much higher than that of electron, and the magnetism of atomic nucleus still has important applications under certain conditions. For example, the magnetic resonance imaging (also known as magnetic resonance CT, CT is the abbreviation of the English term for computerized tomography) used in medicine today is the magnetism of hydrogen atomic nucleus.

Magnetic materials can be divided into soft magnetic materials such as iron and hard magnetic materials such as steel.