What is the formation process of the whole world? Should be adopted concisely by the questioner.

1.16th century, the productive forces flourished and the precursors of world industrialization began to appear.

2. The productive forces are booming, the employment relationship appears, and capitalism begins to sprout;

3. With the opening of new air routes and geographical discovery, the world began to form a whole;

4. The technology of two industrial revolutions has promoted the development of human social transportation;

5. The third scientific and technological revolution, the arrival of the information technology era, the increasingly close contact between human beings, the world is more integrated-the global village.

What is the specific process of pollen formation? Take angiosperms as an example;

The pollen grains of angiosperms are developed from microspore mother cells (also called pollen mother cells) in pollen sacs. Each microspore mother cell undergoes meiosis to form four cells, which are called microspores. The chromosome number of each microspore cell is reduced by half compared with that of microspore mother cell. The first four microspores are arranged together and then separated from each other to form four mononuclear pollen grains.

Shortly after the formation of a single pollen grain, two cells are formed by mitosis: one is a vegetative cell and the other is a germ cell. Vegetative cells are generally larger than germ cells and contain nutrients. The germ cells of some plants then undergo mitosis to form two * * *, so there are three cells in the mature pollen grains. The germ cells of some plants divide in the pollen tube, so they mature.

What is the process of booger formation? 1. White booger formation:

Snuff->; Air drying and water loss->; White booger

2, the formation of black nose or dark green nose:

Snuff->; Air drying and water loss+absorption of air particles->; Black or dark green booger

3, green booger formation:

Viral cold with green nose->; Air drying and water loss->; Green booger (strong smell)

4, yellow booger formation:

Acute sinusitis with thick yellow nose-> Air drying and water loss->; Yellow booger (strong smell)

What is the process of rime formation? Rime, commonly known as hanging trees, is a natural phenomenon similar to the first frost that can be seen in northern winter, and it is a beautiful snow and ice scenery. It is due to the accumulation of frozen and sticky water droplets below zero degrees Celsius in the fog on branches and other objects with the wind, which is manifested as white opaque granular structure deposits. Therefore, rime phenomenon is very common in northern China, and it is also common in southern mountainous areas, as long as there are cooling water droplets in the fog.

When supercooled water droplets (temperature below zero) collide with objects also below freezing point, rime will be formed. When water droplets are very small and freeze as soon as they touch objects, a rime layer or rime deposit will be formed. The rime layer is composed of small ice particles with pores between them, which leads to a typical white appearance and granular structure. Due to the rapid freezing of each supercooled water droplet, the cohesion between adjacent ice particles is poor and it is easy to fall off from the attachment. Rime is most likely to form at the top of the mountain surrounded by Leng Yun. This is also a common form of icing on airplanes. In cold weather, steam fog near springs, rivers, lakes or ponds can also form rime. Rime is a kind of natural beauty that people generally appreciate, but it sometimes becomes a natural disaster. Severe rime sometimes breaks wires and trees, causing losses.

What is the formation process of black holes? Black holes are celestial bodies with infinite density and infinite volume in modern general relativity. The gravity of a black hole is so great that the escape velocity in the event horizon is greater than the speed of light.

A black hole is a singular point with infinite density, infinite curvature of space-time height and infinitesimal central volume, surrounded by an empty sky and invisible. According to Albert Einstein's theory of relativity, when a dying star collapses, it will gather into a point, which will become a black hole, devouring all the light and any matter in the neighboring universe.

The process of a black hole is similar to that of a neutron star: a star is preparing to die, and its core rapidly contracts, collapses and explodes under its own gravity. When all the core materials become neutrons, the contraction process stops immediately and is compressed into dense stars, and the inner space-time is also compressed. But in the case of a black hole, because the mass of the star core is so great that the contraction process goes on endlessly, the neutron itself is ground into powder under the attraction of the squeezing gravity itself, and the rest is the matter with unimaginable density. Due to the gravity generated by high mass, anything near it will be sucked in by it.

It can also be simply understood that stars usually only contain hydrogen at first, and hydrogen nuclei inside stars collide and fuse with each other at all times. Because of the great mass of stars, the energy generated by fusion competes with the gravity of stars to maintain the stability of star structure. Because of the fusion of hydrogen nuclei, a new element helium is produced, and then helium atoms also participate in the fusion, changing the structure and generating lithium. By analogy, according to the order of the periodic table of elements, beryllium, boron, carbon and nitrogen will be generated in turn, and the star will not collapse until iron is generated. This is because iron is quite stable and will not release energy when participating in fusion, but iron exists in stars, which leads to the lack of enough energy in stars to compete with the gravity of massive stars, which leads to the collapse of stars and eventually the formation of black holes. It is called "black" because its density is infinite, and the resulting gravity makes it impossible for the surrounding light to escape. Like neutron stars, black holes are evolved from stars whose mass is dozens or even hundreds times larger than that of the sun.

When a star ages, its thermonuclear reaction has exhausted the fuel in the center and the energy generated in the center is running out. In this way, it no longer has enough strength to bear the huge weight of the shell. Therefore, under the heavy pressure of the shell, the inner core begins to collapse, and the matter will move inexorably to the center, until finally a star with nearly infinite volume and density is formed. When its radius shrinks to a certain extent (it must be smaller than schwarzschild radius), the space-time distortion caused by mass makes it impossible to shoot out even light-a "black hole" is born.

What is the process of acid rain formation? Acidity in acid rain is mainly caused by sulfuric acid and nitric acid. The formation of acid rain is a complicated atmospheric chemistry and indoor process. It is generally believed that acid rain is caused by the emission of acid gases such as SO2 into the atmosphere, which is enriched in some areas, dissolved in water during the process of water condensation to form sulfurous acid [SO2+H2O = H2SO4], and then generated sulfuric acid [2h2so3+O2 = 2h] under the catalysis of some pollutants and oxidation of oxidants.

As far as the situation in China is concerned, firstly, SO2 emissions are larger than nitrogen oxides in general, but in some southern provinces and cities, such as Guangdong and Fujian, SO2 emissions are smaller than nitrogen oxides; Secondly, as far as development is concerned, the number of cars is increasing rapidly, and the emission of nitrogen oxides mainly depends on the emission of cars. Therefore, in the next few years, the emission of nitrogen oxides may exceed SOx. Finally, SO2 will be converted into sulfate through photochemical reaction after entering the atmosphere, which will take some time and may be transported through the atmosphere for a long distance. However, after NO enters the atmosphere, it quickly combines with oxygen to generate NO2 [2NO+O2=2NO2], and then becomes nitrate [3NO2+H2O=2HNO3+NO], which takes a short time and is partially washed to the ground in case of rain. Generally speaking, SO2 contributes a lot to acid rain at present, and the contribution of nitrogen oxides may exceed SO2 in the future.

How is dew formed? What is the process of formation? First, the reason for condensation: When the weather temperature difference is large and the water content in the air is rich, water vapor will condense into droplets. It usually appears when the temperature difference is large in the early morning.

Second, the dew formation process:

1, there is dew in all seasons, especially in autumn. On a clear and cloudless night, the ground heat dissipates quickly and the ground temperature drops quickly.

When the temperature drops, the ability of air to contain water vapor decreases, and the water vapor in the lower atmosphere adheres to grass, leaves, etc. and condenses into tiny water droplets, that is, dew.

2. Dew water can only be formed under the weather conditions of stable atmosphere, small wind, clear sky and rapid heat loss on partially cloudy ground. If there are clouds in the sky at night, the ground is like a quilt. After the heat hits the clouds, part of it turns back to the ground and the other part is absorbed by the clouds. This part of the heat absorbed by the clouds will slowly radiate to the ground in the later stage, and it is difficult for the ground temperature to drop and dew to appear. If the wind is strong at night, the wind makes the upper and lower air communicate, which increases the temperature of the air near the ground and makes the water vapor diffuse, so it is difficult to form dew.

Dew is good for crops. Dew, like rain, can moisten the soil and help plants grow.

Third, the health care function:

1. Some experts made a preliminary study on dew. Chemical experts believe that the "* * * valence bond" between hydrogen atoms and oxygen atoms that make up dew seems to have changed subtly. Nutritionists believe that dew contains some chemicals that are beneficial to human body. The research also shows that dew contains almost no heavy water and has strong permeability. Therefore, plants watered with dew grow faster than ordinary water.

2. At present, some western medical scientists suggest that rolling on the grass covered with dew is extremely beneficial to fitness and skin health. If you don't get enough sleep and your eyelids are swollen, apply absorbent cotton balls dipped in dew on your eyelids to quickly eliminate edema.

What is the formation process of acid rain (as long as H2SO3 is formed)? -

What is the formation process of phenolic resin? Firstly, formaldehyde reacts with phenol to generate monomethylol phenol, then monomethylol phenol continues to undergo addition reaction to generate binary and polybasic hydroxymethyl phenol, and finally polybasic hydroxymethyl phenol undergoes polycondensation reaction to obtain phenolic resin.

Phenolic resin is also called bakelite and phenolic molding compound. Originally a colorless or yellowish brown transparent substance, it is often sold in the market as red, yellow, black, green, brown, blue and other colors, with particles and powder. Resistant to weak acid and alkali, decomposed in strong acid and corroded in strong alkali. Insoluble in water, soluble in organic solvents such as acetone and alcohol. Phenolic aldehyde or its derivatives are obtained by polycondensation.

High temperature characteristics

The most important feature of phenolic resin is its high temperature resistance, which can maintain its structural integrity and dimensional stability even at very high temperatures. It is for this reason that phenolic resin is used in some high-temperature fields, such as refractories, friction materials, adhesives and foundry industry.

Main factors affecting the synthesis, structure and properties of phenolic resin;

(1) chemical structure of raw materials;

(2) molar ratio of phenol to aldehyde;

(3) Acidity and alkalinity of the reaction medium;

(4) Production operation method.

Application:

Phenolic resin is mainly used to make various plastics, coatings, adhesives and synthetic fibers.

What is the process of "cold war formation" in world history? After the end of World War II, the interests of world capitalism allied with the Eastern Group were lost, and the United States and the former Soviet Union, the top powers of the two camps, fell into world hegemony. The cold war is the opposition of two camps, and the political performance is the emergence of two camps; Economically, the United States implemented the Marshall Plan for Western Europe, and the Soviet Union and Eastern European countries established the "Economic Mutual Assistance Committee". The military manifestations are the successive establishment of the NATO-China Treaty, the Korean War, the Cuban Missile Crisis, the Vietnam War and other military confrontations and conflicts. At present, the international symbol of the end of the Cold War is defined as "8 199 19 incident broke out in 65438, and the Soviet Union disintegrated".

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