What is the physical meaning of differential scattering cross section?

at least
Differential scattering cross section plays an important role in the field of collider
Calculated impact
In any case, it's much more successful than beating around the bush
This is the easiest thing to think of at present
Other physical meanings should also be nuclear physics
Read more books about that

The physical meaning of Maxwell equations in Electromagnetics
The scope of the University, I hope to be more detailed

Maxwell equations
The basic laws of electrostatic field and steady magnetic field can be summarized into the following four basic theorems
Gauss theorem of electrostatic field:
Loop theorem of electrostatic field
Gauss theorem of steady magnetic field
Ampere loop theorem of magnetic field
All of the above theorems give the laws of static electric field and steady magnetic field in isolation, and are not applicable to variable electric field and variable magnetic field
Based on the steady field theory, Maxwell proposed the concepts of eddy electric field and displacement current
1. The concept of eddy electric field proposed by Maxwell reveals that the changing magnetic field can excite the electric field in space, and the relationship between the two is obtained by Faraday's law of electromagnetic induction, namely
The above formula shows that any magnetic field changing with time is related to the eddy electric field
2. The concept of displacement current proposed by Maxwell reveals that the changing electric field can excite the magnetic field in space, and through the introduction of the concept of total current, the general form of ampere loop theorem in vacuum or medium is obtained, that is
The above formula shows that any electric field changing with time is related to the magnetic field
From the above two points, we can see that the changing electric field and the changing magnetic field are not isolated from each other. They are always closely linked and excite each other to form a unified electromagnetic field. This is the basic concept of Maxwell's electromagnetic field theory
In Maxwell's electromagnetic field theory, free charge can excite electric field, and variable magnetic field can also excite electric field. In general, the electric field intensity at any point in space should be expressed as
In general, the intensity of magnetic induction at any point in space should be expressed as
Therefore, in general, the basic laws of electromagnetic field should include both the laws of steady electricity and magnetic field, such as equations (1), and the laws of changing electromagnetic field,
According to the concepts of eddy electric field and displacement current proposed by Maxwell, the changing magnetic field can excite the changing eddy electric field in space, and the changing electric field can also excite the changing eddy magnetic field in space. Therefore, the electromagnetic field can exist alone in the space without free charge and conduction current
1. Gauss theorem of electric field. In the space without free charge, the electric field line of vortex electric field excited by changing magnetic field is a series of closed curves
2. The loop theorem of electric field is known by formula (2) in this section. The eddy electric field is a non conservative field, and the loop theorem satisfied is
3. Gauss theorem of the magnetic field. The magnetic field produced by the changing electric field is the same as that produced by the conducting current. It is a vortex field, and the magnetic induction line is a closed line
4. The ampere loop theorem of magnetic field is known by formula (3) in this section. The loop theorem satisfied by the changing electric field and the magnetic field excited by it is
In the above law of changing electromagnetic field, electric field and magnetic field become an inseparable whole
By combining the laws of two kinds of electric and magnetic fields, we can get the basic laws of electromagnetic field, which are called Maxwell equations. The expressions are as follows
The above four equations are called integral form of Maxwell equations
The integral form of Maxwell's equations can be transformed into differential form by means of advanced mathematics. The differential form of equations is as follows
The above four equations can be explained as follows: at any point in the electromagnetic field
(1) The divergence of the potential shift is equal to the volume density of the free charge at the point;
(2) The curl of the electric field intensity is equal to the negative value of the change rate of the magnetic induction intensity at this point;
(3) The curl of magnetic field intensity is equal to the vector sum of conduction current density and displacement current density at the point;
(4) The divergence of magnetic induction is zero everywhere
Maxwell's equation is the basic equation of macroscopic electromagnetic field theory. In the application of these equations, the influence of medium characteristics on electromagnetic field should also be considered,
That is,
And the differential form of Ohm's law
The differential form of the system of equations is usually called Maxwell's equation
In Maxwell's equations, electric field and magnetic field have become an inseparable whole. The equations systematically and completely summarize the basic laws of electromagnetic field, and predict the existence of electromagnetic wave

The weight of an apple is 1 / 8 lighter than that of an orange. How much is the weight of an apple? How much is the weight of an orange heavier than that of an apple? (seeking process) thank you!

When the weight of orange is 1, the weight of apple is 1 - (1 / 8) = 7 / 8
So, the weight of an apple is orange: (7 / 8) divided by 1 = 7 / 8
The weight of an orange is heavier than an apple: (1 - (7 / 8)) divided by (7 / 8) = (1 / 8) divided by (7 / 8) = 1 / 7

Are mean inequality and basic inequality of the same nature? Are they all used to find the most value? Are there other cases to use them?

Form is not the same, there are some differences in the nature of it
Some proof questions will also be used to prove inequality and to use scaling method

A and B are going in opposite directions. A's speed is 70 meters per hour. B's speed is 80% of a's. When a meets B, a travels 71.6 meters more than B. how long does it take them to get there
After how long, to adopt the best answer Oh

71.6 / [70 * (1-80%)] = 179 / 35

If the inequality X-1 ≤ a about X has four nonnegative integer solutions, then the value of integer a is______ ．

The solution set of the inequality X-1 ≤ A is x ≤ a + 1. If the inequality has four non negative integer solutions, then these four must be 0, 1, 2, 3, so 3 ≤ a + 1 < 4, the solution is 2 ≤ a < 3, that is, a = 2

The passenger car and the freight car leave from Party A and Party B at the same time and meet on the way after 6 hours
The bus and the truck leave from a and B at the same time. Six hours later, they meet on the way. After meeting, they continue to move in the same speed and direction. After another four hours, the bus arrives at B, and the truck is 200 kilometers away from A. how many kilometers is the distance between a and B There is only one requirement Can not set unknowns, absolutely not, known answer is 600km

Six hours later, they meet on the way. After meeting, the two cars continue to move in the same speed and direction. After another four hours, the bus arrives at the second place. It shows that the six hour journey of the truck is only four hours, that is to say, the speed of the truck is two-thirds of that of the bus
So the speed of the bus is 200 / (6-4 * 2 / 3) = 60 km
Therefore, the distance between the two places is 60 * (6 + 4) = 600 km

Let set a = {5, | a + 1 |, 2A + 1}. Given that 3 belongs to a, find the value of real number a

When | a + 1 | = 3, then a = 2 or a = - 4, this is 2A + 1 = 5 (rounding off) or - 7, which is consistent with the meaning of the title. When 2A + 1 = 3, a = 1, then | a + 1 | = 2 is also consistent with the meaning of the title, so a = 2 or - 4

Three times the number a is five times the number B, and the number B is a fraction of the number a

A × 3 = B × 5
So: B △ a = 3 / 5

The sum of all the numbers on the natural number 100 ~ 1000 is ()

396

What is the physical meaning of differential scattering cross section?