Side smoke exhaust is divided into centralized smoke exhaust and decentralized smoke exhaust, as well as two combined smoke exhaust methods. Centralized smoke exhaust is to concentrate the smoke at the kiln head and discharge it through the main flue. The advantage is convenient construction, but the disadvantage is that the exhaust temperature is high and it is difficult to control. Decentralized smoke exhaust is to set up smoke outlets in several sections at the beginning of the second section of kiln head, and finally gather in the main flue for discharge. The advantage is that it is easy to adjust the temperature of the preheating zone, but the construction is relatively complicated and the cost is high.
What kinds of ceramics can be divided into according to the place of origin? Divide by purpose
1, daily-use ceramics: such as tableware, tea sets, altars, cans, pots, pots, plates, dishes, bowls, etc.
2. Art (craft) ceramics: such as vases, sculptures, garden ceramics, utensils, photo frames, murals, furnishings, etc.
3. Industrial ceramics: refers to ceramic products used in various industries. It is divided into the following six aspects:
① Building sanitary ceramics: such as bricks, drainage pipes, ceramic tiles, exterior wall bricks, sanitary ware, etc.
② Chemical (chemical) ceramics: all kinds of acid-resistant containers, pipes, towers, pumps, valves, acid-resistant bricks and ashes for chemical industry;
③ Electric porcelain: used as insulator on high and low voltage transmission lines in power industry. Bushings for motors, post insulators, insulators for low-voltage appliances and lighting, insulators for telecommunications, insulators for radio, etc.
④ Special ceramics: Special ceramic products used in various modern industries and cutting-edge science and technology, including high-alumina porcelain, magnesia porcelain, titanium-magnesium porcelain, zircon porcelain, lithium porcelain, magnetic porcelain and cermet.
According to materials, it can be divided into brick or terracotta, pottery, stone tools and semi-porcelain (130 relay). The raw materials are coarse to fine, and the green body is coarse to porous, and then gradually dense, sintered and fired.
Coarse pottery is the most primitive and lowest ceramic ware, usually made of fusible clay. In some cases, clinker or sand can be added to clay to reduce shrinkage. The firing temperature of these products varies greatly, depending on the nature and quantity of impurities contained in the chemical composition of clay. If the porosity of bricks and tiles made of it is too high, the frost resistance of the green body is not good, and the mortar is not easy to cross, so the water absorption should generally be kept between 5 ~ 15%. The color of the green body after firing depends on the content of colored oxides in clay and the firing atmosphere. When fired in the oxidation flame, it is mainly yellow or red, and when fired in reducing flame, it is mainly cyan or black.
The blue bricks in China's building materials are yellow or red clay containing fe2o 3, which is calcined by reducing flame when the fire is near, so that Fe2O3 is reduced to FeO and becomes cyan. Pottery can be divided into ordinary pottery and exquisite pottery. Ordinary pottery refers to products with porous coloring bodies such as pottery pots, jars, altars, urns and refractory bricks. The water absorption of the green body of fine pottery is still 4 ~ 12%, so it is transparent and opaque, and it is generally white with color. Glazes are mostly fusible glazes containing lead and boron. Compared with stoneware, there is less flux, and the sintering temperature does not exceed 1300℃, so the green body is not fully sintered; Compared with porcelain, it has lower requirements for raw materials, greater plasticity and lower firing temperature. It is not easy to deform, and can simplify the processes of product forming and filling. However, the mechanical strength and impact strength of fine pottery are less than porcelain and stoneware, and its glaze is softer than the above products. When the glaze layer is damaged, the porous body is easy to be polluted, which affects the hygiene.
Fine pottery can be divided into clay, calcareous, feldspar and clinker according to different body components. Clay pottery is close to ordinary pottery. Lime fine pottery uses limestone as flux, and its production process is similar to that of feldspar fine pottery, but its quality is not as good as that of feldspar fine pottery, so it has been rarely produced and replaced by feldspar fine pottery. Feldspar fine pottery, also known as hard fine pottery, takes feldspar as flux. It is the most perfect and widely used pottery. In modern times, many countries have used it to mass-produce daily tableware (cups, plates, etc.). ) and sanitary pottery instead of expensive porcelain. Hot material fine pottery is to add a certain amount of clinker to the fine pottery blank to reduce shrinkage and avoid waste. This kind of blank is mostly used for large and thick tire products (such as bathtub, washbasin, etc.). ).
In ancient books in China, stoneware was called "stone tire porcelain". Its green body is dense and completely sintered, which is very close to porcelain. But there is no vitrification, and the water absorption rate is still below 2%. The green body is opaque and white, and most of them are allowed to develop color after firing. Therefore, the requirements for the purity of raw materials are not as high as porcelain, and raw materials are easy to obtain. Stoneware has high strength and good thermal stability, which is very suitable for modern mechanized washing, and can successfully survive the sudden change of temperature from refrigerator to oven. In the international market, due to the development of tourism and the socialization of diet, the sales of stoneware are larger than that of pottery.
The green body of semi-porcelain is close to porcelain, but it still has 3 ~ 5% water absorption after firing (the water absorption of real porcelain is below 0.5%), so its use efficiency is not as good as porcelain, but better than fine pottery.
Porcelain is a higher stage of ceramic development. Its characteristic is that the green body has been completely sintered and vitrified, so it is dense and impermeable to liquid and gas. The thin part of the tire is translucent and the cross section is shell-shaped. When you lick it with your tongue, it feels slippery and does not stick to your hands. Hard porcelain has the best performance among ceramics. Used to make high-grade daily utensils, electric porcelain, chemical porcelain, etc.
Soft porcelain has more flux, lower firing temperature, lower mechanical strength and lower thermal stability than hard porcelain, but it has high transparency and rich decoration, and is mostly used to make artistic display porcelain. As for sintered porcelain and bone porcelain, their firing temperature is similar to that of soft porcelain, and their advantages and disadvantages are similar to that of soft porcelain, so they should belong to the scope of soft porcelain. These two kinds of porcelain are difficult to produce (the plasticity and drying strength of the body are poor, and the deformation is serious when firing), so the production is not universal. Britain is a famous producer of cinerary porcelain, and Tangshan, China also produces cinerary porcelain.
Special ceramics are developed with the rapid development of modern electrical appliances, radio, aviation, atomic energy, metallurgy, machinery, chemistry and other industries, as well as cutting-edge science and technology such as computer, space technology and new energy development. The main raw materials used in these ceramics are no longer clay, feldspar and quartz, and some green bodies also use some clay or feldspar. However, purer oxides and raw materials with special efficiency are used, and the manufacturing process and efficiency requirements are also different.
According to its nature, productivity can be divided into several types: primitive collective labor productivity of primitive crude benzene hand tools, simple individual labor productivity of specialized and perfect hand tools, and socialized labor productivity with strict division of labor and cooperation.
What kinds of break exercises can be divided into? He wrote things like locking, popping, disconnecting and fluctuating. He originated from the improvisation of American street dancers. Most of these street dancers are black or Mexican. Perhaps it is the so-called "entertainment for the poor". Most of these popular street dances originated in Brooklyn, new york, USA (this area is full of poor blacks or Mexicans). These black and Mexican children mix and dance in the streets all day, naturally forming various factions and naturally developing different styles in the dance. At present, street culture has also come to China with the influence of foreign media, but it is undeniable. When street culture is in full swing all over the country, Haikou, as the capital of special economic zones, has not received much attention. Tracing back to the source, when people face performers with strange clothes and hairstyles, they all feel a kind of disgust from the bottom of their hearts, but when they face this form of street dance, they are not recognized because the dancers' bodies are greatly distorted. Hip-hop, the cultural category of hip-hop, originated in the United States in the 1980s. Because this kind of dance appears in the street, regardless of the venue equipment, it is called hip-hop, which has strong participation, performance and competitiveness. In the gradual development, street dance teenagers have formed an ideology and behavior. They use street dance to publicize their individuality, show their youthful vitality and express their enterprising attitude towards life. They emphasize the concept of "being yourself, enjoying life and being brave in challenges". The development of hip-hop in Japan and South Korea With the popularity of hip-hop culture in the world, hip-hop has also spread rapidly around the world. Street dance was introduced to Japan when it was formed, and then to South Korea. The Japanese created and developed many new forms of street dance, and paid more attention to dance. Koreans have integrated hip-hop into their own understanding and created a hip-hop variant culture with national characteristics: youthful and beautiful song and dance combinations, melodious and fast-paced music, concise and neat dances, gorgeous and exaggerated shapes ... This culture has been popular in China since 1997 and is called "Korean Wave". This hip-hop variant culture of Japan and South Korea has formed a strong cultural influence on other Asian countries. The types of street dance are based on action, and street dance can be divided into Hip-Hop and Breaking. Break: Skilled street dance requires dancers to have high strength, flexibility and coordination. It is a highly skilled sports dance, so it was first loved by domestic teenagers. Teenagers who dance this type of dance are called B-Boy/B-Girl. Breaking the GRIL, abbreviated as BBOY BGRIL, requires strength and balance, as well as physical flexibility. It is a difficult dance, which can be roughly divided into two types: style movement, power movement. Rotating on the ground with hands, head and body is called POWERMOVE (big floor); Landing on all fours, combined with a tricky handstand, is called style MOVE (small floor). It seems that the dance is also mixed with movements similar to China Kung Fu, such as kicking, somersaults, jumping, frog turning, windmill, helicopter, thunderbolt, pommel horse, turning head … and various combinations, which are quite dangerous. Of course, you can also match the movements you want to show when dancing.
What kinds of colored sand can be divided according to their uses? With the continuous development of society, the application scope of colored sand is more and more extensive, and different industries have different requirements for colored sand. Next, let's briefly understand that different kinds of natural colored sand have different uses. Colored sand can be mainly divided into the following categories:
1, antibacterial colored sand
Used in hospital operating rooms and aseptic operation factories. These environments need strong antibacterial properties, and bacteria are inactivated when they touch the ground wall. The amount of bacteria on the common ground is 1. 1000 ~ 68000 cm2, and the inactivation rate is 95%, but actually it is expected that the sterilization requirement will reach 99%.
2. Antistatic colored sand
Mainly used for the walls and floors of dust-free workshops for processing electrical components. The production method is also to add antistatic agent to the coating or ceramic layer. There are many kinds of antistatic agents to choose from.
3. Wear-resistant colored sand
Used in garages, parking lots, aprons, etc. , with anti-slip and wear-resistant functions. The production method is to add wear-resistant materials to pigment paste or use thin film nano-diamond on the surface of colored sand.
4, heat insulation colored sand
With the shortage of energy, countries are increasingly demanding energy conservation, and the roof is the focus of building energy conservation. As far as asphalt shingles or coiled materials are concerned, except for the white surface, the surface of other colors will absorb most of the solar infrared rays, and the heat insulation effect cannot be achieved. At present, a kind of "cold black asphalt shingle" has entered the stage of engineering experiment, and its reflectivity is four times higher than that of ordinary asphalt shingles. Hot asphalt shingles play an important role in heat-insulating colored sand, which is the main way for nano-dispersed materials to replace ordinary pigments.
5. Fluorescent colored sand
Mainly used in courtyards, roads, airports and other places that need large-scale display or special instructions when it is dark. Generally, light storage materials are added to colored sand, and crystal light storage materials or polymer light storage materials are usually used. This colored sand absorbs light energy for storage during the day and fluoresces at night. Displays objects such as stairs and handrails.
Fluorescent sand is concerned because it doesn't need to consume energy at night. However, the use of polymer optical storage materials is limited because they are not anti-aging. Crystal fluorescent colored sand can be exposed for a long time without changing its efficiency, but the price is too high to be widely promoted. At present, all countries are actively developing low-priced crystal fluorescent colored sand from the perspective of energy saving.
What kinds of poetry can be divided into according to form? Poetry can be divided into ancient poetry and modern poetry.
Classification of ancient poems:
1. According to the rhythm, poetry can be divided into two categories: ancient poetry and modern poetry. Classical poetry and modern poetry are concepts formed in the Tang Dynasty, which are divided from the perspective of poetic rhythm.
2. According to the content, it can be divided into narrative poems, lyric poems, farewell poems, frontier poems, pastoral poems, nostalgic poems (poems about history), mourning poems and satirical poems.
Classification of modern poetry:
There are also many ways to classify poems, which can be divided into different categories according to different principles and standards. The basics are as follows:
1. Narrative poems and lyric poems. This is divided according to the expression of the content of the work.
2. Metric poems, free poems and prose poems. This is classified according to the phonological meter and structural form of the language of the work.
What kinds of hiphop can be divided into? Well, I can't stand the first floor now. Who told you that newschool refers to street dance? The old and the new are related to the history of the east and west coasts of the United States. Not only hip-hop is divided into the new school and the old school, but also the culture derived from hiphop, including streetball and rap. Hiphop is divided into four elements, hip hop, graffiti, rap and DJ. Later, schools, tattoos and ancient costumes were derived one after another. Crump and Quaramp are not fighting dances. They imitate clowns first. Besides, reggae is one-sidedly understood as sexy in China. In fact, most foreign reggae masters are men, which is not a simple sense of sex and wild dance.
What kinds of poems can be divided into? 1. According to the rhythm, poetry can be divided into two categories: ancient poetry and modern poetry. Classical poetry and modern poetry are concepts formed in the Tang Dynasty, which are divided from the perspective of poetic rhythm.
(1) Classical poetry: including ancient poetry (poems before the Tang Dynasty), songs of Chu and Yuefu poems. Poems in ancient poetry genres such as Song, Gexing, Quotations, Qu and Ling are also ancient poems. Classical poetry does not talk about antithesis and rhymes freely. The development track of classical poetry: The Book of Songs → Chu Ci → Han Fu → Han Yuefu → Wei, Jin, Southern and Northern Dynasties Folk Songs → Jian 'an Poetry → Tao Poetry and other literati five-character poems → Tang Dynasty Ancient Style New Yuefu.
① Chuci: a form of poetry created by Qu Yuan during the Warring States Period, characterized by the use of dialect and phonology of Chuci, with strong Chu color.
② Yuefu: It was originally the official name in charge of music in the period of Emperor Wu of the Han Dynasty, and later became a poetic name. Music songs collected and created by Yuefu officials in the Han, Wei, Southern and Northern Dynasties are called Yuefu for short. Poems written by poets in Wei, Jin, Tang and beyond are quasi-Yuefu, which makes them quasi-Yuefu and quasi-Yuefu, although they are not enjoyable.
(3) Gexing style: it is a variant of Yuefu poetry. After the Han and Wei Dynasties, there were quite a few Yuefu poems with the theme of "Song" and "Xing". Although the names are different, there is no strict difference between them. They all mean "Song". Their syllables and meter are generally free, and the form is the archaic form of five words, seven words and miscellaneous words, which is full of changes. Later, they had the style of "Gexing". In the Tang Dynasty, poets in the early Tang Dynasty created Yuefu poems, in addition to following the old themes of Yuefu in the Han, Wei and Six Dynasties, a few poets also created new themes. Although it was renamed Yuefu, it was not limited to temperament, so it was called New Yuefu. This kind of poetry has been greatly developed by Li Bai and Du Fu.
(2) Modern poetry: Compared with classical poetry, modern poetry is also called modern poetry, which is a kind of metrical poetry formed in the Tang Dynasty. There are two kinds, and there are strict rules on the number of words, sentences, level tones and rhymes.
(1) a "quatrains", each sentence four sentences, referred to as five words, referred to as seven words.
(2) One kind is called "metrical poem", each poem has eight sentences, five characters are abbreviated as five laws, seven characters are abbreviated as seven laws, and more than eight sentences are called excluded laws (or long laws).
(3) Ci: also known as Yu Shi, long and short sentences, Qu Zi, Qu Zi Ci, Yuefu, etc. Its characteristics: the tone has a fixed frame, the sentence has a fixed number and the word has a fixed tone. The number of words can be divided into long tune (above 9 1 word), middle tune (59-90 words) and minor tune (below 58 words). Words can be divided into monosyllabic and disyllabic, and disyllabic is divided into two paragraphs, in which the level and number of words are equal or roughly equal, and monosyllabic is only one paragraph. A paragraph of a word is called a que or an article, the first paragraph is called Qianque, Shangque and Shangpian, and the second paragraph is called Houque, Xiaque and Xiapian.
(4) Qu: also known as Yuefu. Yuanqu includes Sanqu and Zaju. Sanqu rose in the Jin Dynasty and flourished in the Yuan Dynasty, and its style was similar to that of Ci. Features: the number of words can be added with interlining, and more oral English is used. Sanqu includes poems and songs. The number of songs is a coherent set of songs, ranging from two to dozens. Each group number takes the song of the first song as the name of the whole set of songs, and the whole set of songs must be in the same palace tune. It has no guests, but only oratorios.
2. According to the content, it can be divided into farewell poems, frontier poems, pastoral poems, nostalgic poems (poems about history), mourning poems, wandering poems and in my heart forever's poems.
(1) nostalgic poems.
Generally, I miss people and things in ancient times. Poetry about history often distorts historical facts and reality, or regrets personal experience or criticizes social reality.
(2) poetry.
Characteristics of object-chanting poems: take a certain object as the description object in content, and grasp some of its characteristics to describe it. Ideologically, it is often to express one's wishes. From things to people, from reality to nothingness, write spiritual character. Commonly used metaphor, symbol, personification and contrast.
(3) Landscape pastoral poetry.
Xie Lingyun in the Southern Dynasty created landscape poetry, Tao Yuanming in the Eastern Jin Dynasty created pastoral poetry, and in the Tang Dynasty, the school of landscape pastoral poetry represented by Wang Wei and Meng Haoran appeared. Landscape pastoral poetry is good at describing natural scenery, pastoral scenery and comfortable seclusion life, with meaningful and beautiful poetic landscape, quiet and elegant style and clear and elegant language.
(4) War poems.
Poems about frontier fortress and war have existed since the pre-Qin period and developed into the Tang Dynasty. Because wars are still frequent, rulers attach more importance to martial arts than literature, and it is easier for scholars to win reputation by inviting frontier courts than by passing imperial examinations. In addition, in the prosperous Tang Dynasty, frontier poems with magnificent feelings were greatly developed, forming a new school of poetry, with representatives such as Gao Shi, Cen Can and Wang Changling.
(5) Travel poems and in my heart forever's poems.
The ancient people's long-term exile, long-term wandering, or long-term guarding the border will always cause strong homesickness and homesickness, so there are many such poems. They either write about their nostalgia for a trip, or their thoughts about their relatives and friends, or their homesickness, or their thoughts about being pregnant in the boudoir. In writing, I feel hurt by touching the scene, feeling in time, expressing my feelings with things, expressing my feelings because of dreams, or expressing my feelings with wonderful metaphors.
To appreciate this kind of poetry, we should determine the emotional category on the basis of overall perception; Grasping the image and constructing the picture; Grasp the key words and appreciate the artistic features.
(6) Farewell poems.
In ancient times, due to inconvenient transportation and underdeveloped communication, it was often difficult for relatives and friends to meet for several years, so the ancients paid special attention to parting. On the occasion of parting, people often set up wine farewell parties, fold willows to send them away, and sometimes sing poems to bid farewell, so parting has become an eternal theme of ancient literati. Because everyone's situation is different, the specific content and ideological tendency written in farewell poems are often different. Some express their feelings of parting directly, some express their feelings by spitting out the anger in their chests or expressing their wishes, some focus on the pain of parting without hating, some focus on persuasion, encouragement and comfort, and some have both.
(E) the classification of modern poetry
There are also many ways to classify poems, which can be divided into different categories according to different principles and standards. The basics are as follows:
1. Narrative poems and lyric poems. This is divided according to the expression of the content of the work.
(1) Narrative poem: There are relatively complete story lines and characters in the poem, which are usually expressed by the poet's singing style. Epic, story poem and poetic novel all belong to this category.
(2) Lyrics: It mainly reflects the social life by directly expressing the poet's thoughts and feelings, and does not require complete stories and characters. Such as love songs, carols, elegies, elegies, pastoral songs, satirical poems, etc. There are many such works, so I won't list them one by one.
Of course, narration and lyricism are not absolutely separated. Narrative poetry is also lyrical, but its lyricism requires close combination with narrative. Lyric poems often describe some fragments of life, but they can't be spread out, and they must obey the needs of lyricism.
2. Metric poems, free poems and prose poems. This is classified according to the phonological meter and structural form of the language of the work.
(1) Metric poetry: It is a poem written according to certain formats and rules. It has strict rules on the number of lines, the number of words (or syllables), the tone and rhyme, the antithesis of words and the arrangement of sentence patterns. Such as the metrical poems, quatrains and songs in China's ancient poems and the European sonnets.
(2) Free verse: it is a newly developed poetic style in modern Europe and America. It is not limited by metrical rules, has no fixed format, pays attention to natural and internal rhythm, and uses rhymes roughly similar or without rhymes. The number of words, lines, sentence patterns and tones are relatively free, and the language is relatively popular. Whitman, an American poet (1819-1892), is the founder of European and American free verse, and Leaves of Grass is his main collection of poems. This poetic style has also become popular in China since the May 4th Movement.
(3) Prose poetry: it is a literary genre with both prose and poetry characteristics. There is a poetic mood and a sense of * * * in the works, which are often full of philosophy, pay attention to the natural rhythm and the beauty of music, and are short in length, like prose, which does not rhyme, such as Lu Xun's Wild Grass.
What kinds of football can be divided into? Terms of curveball football. Kicking technique of guiding the ball to move in an arc. In the execution of football, because of the strong rotation, the air on both sides is different. Because the ball is executed in an arc, it is commonly known as "banana ball". When kicking a curveball, the part where the foot touches the ball should deviate from the center of gravity of the ball. Often used to bypass the defender in the middle of the passing route, or confuse the goalkeeper when shooting, making him make a wrong judgment. When a direct free kick is penalized, curveball shooting is an important way to score.
Terms of diving football. It is difficult for the goalkeeper to catch the ball. One foot pushes hard on the same side of the ball, and the other leg bends its knees to make the body jump out to catch the ball. When landing after catching the ball, press the ball with both hands, land on the forearm side first, and protect the ball with one group. Because it jumps from the side, it increases the range of catching the ball, so it can catch the ball that is difficult to catch with other actions.
Another name for a defender who undertakes a specific defensive task in a football match. 1966 The 8th World Football Championship was named after arranging a player to strengthen defense behind the back line under the influence of the tactical idea of "persisting in steady attack". The player's duty is to defend only without attacking, perform a single defensive task to make up the position, and "clear" the ball in front of his own goal.
Another name for the trailing centre-back in the "1333" formation in the free football match. There is no fixed defensive object in defense, so you can flexibly fill the position and save the day, so that other players, especially the three guards, have no worries when marking people. It is the development of the scavenger's kicking method, which is not only a defense, but also an opportunity to insert into the offensive front. As a "free man" according to the requirements of duties, the players have comprehensive skills, strong tactical awareness and rich competition experience, which is the core of organization, command and defense.
One of the offensive and defensive tactics of football. A team with 10 players, except the goalkeeper, is called "all football". According to the needs of attack and defense in the game, each player can play the role of a player at any position. This tactic breaks the shackles of formation on players and can fully mobilize and give play to the enthusiasm of players. At the same time, it also puts forward higher requirements for players' physical quality, technology, tactics and will quality, and fighting style. This style of play appeared in the 10 World Football Championship in10, 974, and was hailed as the third revolution in the history of international football.
One of the offensive tactics of football. Refers to the tactical method of pushing the ball near the opponent's end line and then passing it to the opponent's goal through individual dribbling or collective cooperation in sideline attack. In the rapid advance, the attacker often uses the advantage of the other defense line to outflank in order to score goals under the unstable position.
Peripheral passing is also called "45-angle passing". One of the offensive tactics of football. When the attacking player gets the ball near the sideline at an angle of about 45 with the opponent's goal, he passes the ball to his partner near the opponent's restricted area with a long pass, so that the partner can attack continuously with a header, which is called "peripheral pass". Especially when the defender has returned to the defense in time, and the road leading to the opponent's goal has been blocked in the area 30-40 meters in front of the goal, or the attacker has a tall striker with strong ability to fight for the top, this kind of play can achieve good results.
Tactical terms of cross-transposition football. In order to get rid of the opponent's defense, the attacker changed his position left and right during running. The most common ones are: the left player sprints to the right player to catch the ball, and the right player passes the ball to the left position. This tactical cooperation has changed the way players play football only in their own positions, making the tactics more changeable.
Long pass is one of the offensive tactics to break through football. Tactical methods to break through the opponent's defense by using long-distance passing. In contemporary football matches, it is often used for quick counterattack. Defender steals the ball in front of his own goal, taking advantage of the opportunity when the opponent failed to return to the defense, passed it to his partner to break through the opponent's defense before the attack.
Insert one of the offensive tactics of attacking football. Refers to the avant-garde and defender players who are located in the second and third lines and insert the first line to participate in the attack. Because of the deep distance, it is easy to get rid of the opponent's defense, and the insertion of second-and third-line players is hidden and sudden. Therefore, it is more threatening. It is an important symbol of all-attack and all-defense tactics that the defender inserts into the forward line and directly participates in the attack.
One of the defensive tactics of regional defensive football. Each player divides a certain defensive area according to his position, and within a limited range, he mainly adopts the defensive mode of standing position instead of pressing people to stare at people. This makes it easier for the attacking team to pass and catch the ball, and it is more difficult to defend when there are more than two attacking players in the same area. This defensive tactic is passive and can't meet the needs of football development, so it is rarely used now.
Tactical terms of auxiliary football. A cooperative method of collective defense in competition. Refers to a defender. When one player is broken by an opponent, another player blocks. Complementarity between the two is the basis of collective defense cooperation. Keeping a proper distance and angle between defenders is the premise of making up positions in time. In the past, it mainly refers to the cooperation of the defensive side in defense. Contemporary football adopts total football's tactics, and the content of supplementary position has also developed accordingly. In an attack, the exchange of positions between the players who are forwards and defenders has also become one of the important contents of position replacement, which puts forward higher requirements for the technical and tactical awareness of position replacement players.
One of the defensive tactics of intensive defense. The area 30 meters in front of the goal is usually called "danger zone". In the game, in order to stabilize the defense, both sides often organize a considerable number of people to guard this area and form a dense state, so as to strengthen the protection, narrow the gap and block the breakthrough of the other side. This is the so-called dense defense tactics.
Offside is a defensive tactic. According to the rules: when the attacker receives the ball, if there are less than two defenders between the opposing end lines, it is offside. Using this rule, the defender suddenly runs forward when the opponent's player touches the ball, resulting in the situation that there is a defender between the opponent's receiver and his own end line, which makes the opponent offside foul.
Anti-offside tactics This is an offensive tactic aimed at the opponent's "offside" tactics. When the attacker realizes that the defender is sabotaging his attack by creating offside tactics, he should change the passing direction in time, so that the player behind him can insert the ball or directly take the ball to push the shot quickly, thus making the opponent fall behind.
Fence tactics are also called human wall tactics. In the dangerous area in front of your house, when the opponent takes a free kick, several defenders line up side by side as a "human wall" to help the goalkeeper block some angles of the opponent's shot.
A passing tactic in attacking against the wall, that is, two people pass one person, two people pass everything, and the passer who catches the ball passes the ball once, so that the ball passed by the passer seems to hit the wall, thus speeding up the passing speed, hence the name.
What kinds of steering gear can be divided into? There are two kinds: one is the reciprocating plunger steering gear, whose principle is to produce linear motion through the conversion of high and low pressure oil and convert it into rotary motion through the rudder stock. The other is the rotary vane steering gear, whose principle is that high and low pressure oil directly acts on the rotor, which is small in size and high in efficiency, but high in cost.