After the explosion of nuclear power plant units caused by the earthquake in Japan, people are very concerned about the possible nuclear pollution. By the end of 1970s, human beings had suffered five nuclear pollution incidents, and the book "5000-year disaster records of the world that we must know" described in detail the causes and consequences of these five nuclear pollution incidents.

　　　　Japan was bombed by atomic bomb.

　　　　Hiroshima Prefecture in the southwest of Honshu, Japan gradually developed into a military stronghold in the mid-19th century. German fascism, the chief culprit of World War II, declared unconditional surrender on May 8, 1945. On July 26th, the United States, Britain and China jointly issued the Potsdam Declaration, ordering Japan to surrender unconditionally and quickly, but the Japanese government turned a deaf ear.

　　　　In order to force Japan to surrender quickly, at 8: 15 on August 6, 1945, the US military dropped an atomic bomb codenamed "Little Boy" in downtown Hiroshima, Japan. "Little Boy" is a uranium bomb with a length of 3 meters and a diameter of 0.7 meters. It contains 60 kilograms of highly enriched uranium and weighs about 4 tons. The TNT equivalent is 15,000 tons. The atomic bomb exploded in the air 600 meters above the ground, instantly rolling up a huge mushroom-shaped smoke cloud, and Hiroshima city suddenly became a scorching sea of fire.

　　　　In this man-made tragedy, the intense light waves generated by the atomic bomb explosion made thousands of people blind. The high temperature of 1 billion degrees makes everything go up in smoke; Radiation rain makes some people slowly die in the next 20 years; All the buildings were destroyed by the strong wind formed by the shock wave.

　　　　According to statistics, before the tragedy, the population of Hiroshima was more than 340,000, and most people near the explosion center died. On that day, more than 88,000 people died, and more than 51,000 people were injured and missing. More than half of the buildings were destroyed to varying degrees. However, this tragedy did not make the Japanese government aware of the seriousness of the problem and still went its own way, so the US military chose to continue.

　　　　At 11: 02 am on August 9, 1945, the US military carried out the second atomic bomb attack on Japan, targeting Nagasaki. This attack dropped the atomic bomb "Fat Man" into the center of Nagasaki, which was absolutely as destructive as the last time. "Fatty" is a plutonium bomb with a length of about 3.6 meters, a diameter of 1.5 meters and a weight of about 4.9 tons. The TNT equivalent is 22,000 tons and the explosion height is 503 meters. "Fat man" uses a complicated "implosion" detonation system, which consists of four different fuzes: air pressure, timing, radar and impact.

　　　　The tragedy caused half of the population in Nagasaki to be killed or missing that day, and more than 60% of the buildings were destroyed.

　　　　Although the two atomic bombs dropped on Hiroshima and Nagasaki were originally intended to force Japan to surrender as soon as possible, they objectively brought indelible pain to the local people. Even the survivors suffered from radiation sequelae such as cancer, leukemia and skin burns. But more is the trauma of the soul, which can never be washed away.

　　　　2. Chernobyl nuclear disaster

　　　　In 1970, the Chernobyl nuclear power plant in northern Ukraine of the former Soviet Union was completed. The nuclear power plant provided 10% of electricity to Ukraine and consisted of four nuclear reactors.

　　　　People generally don’t doubt products such as 3C certification, or products that are well-known. But the big explosion on April 26, 1986 changed the Soviet people’s trust in the Chernobyl nuclear power plant and changed all this.

　　　　On the night of April 25th, 1986, the staff of Chernobyl Nuclear Power Station were preparing to carry out the safety test of Reactor No.4, and the test officially started in the early morning of April 26th. In order to improve the work efficiency during the test, they deliberately violated the operating regulations: a large number of control rods were pulled out, which regulated the temperature of the reactor core. Pulling them out was a fatal mistake. Because there is no control rod to adjust the temperature, the core is overheated. At 1: 23 a.m. on 26th, the staff was lucky enough to operate illegally again, and pressed panic button to shut down the nuclear reactor. At this time, there was a conflict between the original intention and the actual situation, and they wanted to stop the test immediately, but the sudden interruption of power supply caused the main cooling system to stop working, and the reactor was out of control! The water in the core was immediately decomposed into hydrogen and oxygen by strong radiation, and the high concentration of hydrogen and oxygen immediately led to the big explosion of the No.4 nuclear reactor.

　　　　The 2000-ton steel roof was lifted by the explosive force, and a huge fireball suddenly rose from the reactor, so disaster came. In this way, 8 tons of nuclear fuel fragments and high-level radioactive materials were ruthlessly thrown into the dark night sky in an instant, and the high temperature and high-speed radiation dose of 2000 degrees Celsius also swallowed everything around. There were cries and shouts on the ground and a sea of fire.

　　　　Half an hour later, rescuers rushed to the No.4 reactor, and all the fire engines and air force helicopters were used. Nearly 5,000 tons of fire-fighting materials such as dolomite, sand, boride, soil and lead were thrown from the air, and the fire was gradually extinguished.

　　　　In the first few days of this nuclear explosion, many workers and people who participated in the aftermath of the accident were killed or injured due to high radiation. According to the survey results, as many as 300 people died from high-dose radiation, and 30 people died on the spot. After the disaster was slightly controlled, a large number of workers were rushed to the Chernobyl clean-up site. The former Soviet government mobilized hundreds of thousands of people to prevent radioactive substances from entering the groundwater. For this reason, a black building with a length of 160 meters, a width of 110 meters and a height of 75 meters was built with steel, and all the remaining materials of the No.4 nuclear reactor were sealed inside. This building was called the "sarcophagus" because of this catastrophe.

　　　　After the disaster, residents living within a radius of 30 kilometers around the nuclear power plant were evacuated urgently, and this area was turned into an isolated area, and no one was allowed to enter or leave casually. Subsequently, the government evacuated a large number of residents in Puri Piater, with as many as 130,000 evacuated residents.

　　　　In order to avoid unnecessary panic, the Soviet Union tried to hide the accident in the past, because the relationship between the Soviet Union and the West was very bad at that time, so it did not inform its neighbors. However, the leaked radioactive dust is inhuman and does not have such a clear concept of national boundaries. Instead, it keeps drifting over northern Europe, eastern Europe and western Europe, and the harm areas are increasing. The wave of radiation swept by the wind brought a flying disaster to the whole of Europe.

　　　　European countries have been aware of the strange situation of the air one after another and issued statements one after another. Sweden claims that the radioactive dust in its atmosphere is five times higher than usual; Denmark claims that the radiation level in the air is four times higher than usual; Finland has the highest radiation level, and the radiation level in its north and central parts is 10 times higher than normal. Romania, Yugoslavia and other countries have also been harmed to varying degrees. Because these countries have conclusive evidence and strongly protested to the Soviet Union, the Soviet Union had to announce the truth of this nuclear explosion.

　　　　This nuclear explosion is the biggest nuclear disaster since World War II. Fifty-five thousand people died in the rescue work, 150 thousand people were disabled, and a large number of ecological refugees were also caused.

　　　　3. Three Mile Island Nuclear Accident

　　　　At 4: 00 a.m. on March 28th, 1979, in the operation room of the reactor group 2 of Three Mile Island Nuclear Power Station in Pennsylvania, USA, there was a great uproar and confusion. A large amount of radioactive material overflowed after two hours.

　　　　It was not until six days later that the core temperature began to drop and the steam bubbles disappeared-the threat of hydrogen explosion was relieved, and the reactor was finally paralyzed. The American people were all shocked when they learned the news, and residents near the nuclear power plant were even more frightened. About 200,000 people were evacuated from this area. People have held rallies and demonstrations, demanding that nuclear power plants be stopped or shut down. The governments of the United States and some western European countries have also had to re-examine their plans to develop nuclear power.

　　　　The unexpected nuclear leakage accident was caused by the failure of the water pump in the secondary circuit: the workers failed to open the valve of the accident cooling system after overhaul a few days ago, which led to the automatic operation of this system, and the water in the secondary circuit was still cut off. When the temperature and pressure in the reactor rise in this case, the reactor will automatically stop and the pressure relief valve will automatically open, releasing part of the steam-water mixture in the core. At the same time, when the pressure in the reactor dropped to normal, the pressure relief valve failed to return to its seat automatically due to the fault, so that the core coolant continued to flow out and the pressure dropped below normal, so the emergency core cooling system was automatically put into operation, but the operator made a wrong judgment, instead, the emergency core cooling system was closed and water injection into the core was stopped. The above management and operation errors are intertwined with equipment failures, which makes a small failure expand rapidly and sharply, and finally causes a serious accident of core melting. Fortunately, in this accident, the main engineering safety facilities were automatically put into use, and the reactor had several safety barriers (fuel cladding, primary pressure boundary and containment, etc.), and there were no casualties. Only three workers were exposed to the allowable dose slightly higher than half a year.

　　　　The three mile island accident has relatively little impact on the environment. This is the first and most serious commercial nuclear accident in the United States, which changed the center and direction of the nuclear industry in the United States, made the American people strongly appeal to the government to take action to stop the construction of nuclear power plants, and widely publicized the dangers of using atomic fuel to generate electricity.

　　　　4. Nuclear explosion of Ural storage tank

　　　　On September 29th, 1957, in the Urals region, a large nuclear industry gathering area of the Soviet Union, an underground nuclear waste storage tank between the cities of Keshtam and Chelyabinsk suddenly exploded. The violent explosion sprayed radioactive dust and substances into the sky like a volcanic eruption, and its power was 100 times that of the atomic bomb dropped by the United States on Hiroshima in 1945.

　　　　A 10-kilometer-diameter smoke cloud with radioactive element strontium 90 lifted off. More than 10,000 residents immediately evacuated from the polluted area. Maidevijeff, a geneticist in the former Soviet Union, estimated that several hundred people died of radiation a few days after the explosion, and at least 1,000 people died of radiation that year.

　　　　Due to the extremely bad weather, the strong wind blew the radioactive smoke clouds hundreds of kilometers away, resulting in 3000 square kilometers of nuclear pollution in the southern Urals, with no vegetation in the area and thousands of people suffering from radiation sickness. However, when the residents exposed to nuclear radiation were sent to the hospital, doctors did not know about radioactive nuclear medicine and how to treat the patients according to the amount of radiation received. As a result, many patients were on the verge of death. Thousands of people died one year after the accident, and tens of thousands died three years later.

　　　　As we all know, plutonium in nuclear waste is an insoluble element, and most of plutonium in nuclear waste in Ural region is absorbed by soil. When water soaks into the soil where plutonium is accumulated, plutonium reacts with water, triggering a chain reaction, and the water is quickly heated into steam, and the pressure of steam increases, resulting in a strong explosion, thus causing this appalling nuclear disaster.

　　　　When the nuclear waste disposal link was not solved, Khrushchev, then general secretary of the CPSU, ordered the furnace to be turned on in advance in order to compete with the Americans, regardless of the opposition of scientists. In order to save the cost of nuclear waste treatment, the Soviet authorities piled up nuclear waste in the forest areas of Urals, thus forming a large-scale radioactive waste storage site, leaving a major hidden danger.

　　　　All roads and railways leading to the area were closed for a year. A year later, a checkpoint was set up 50 kilometers outside the area, and all motor vehicles entering the area (which is limited to open) must be inspected, all windows closed, no photos allowed, and they must pass at the highest speed without stopping. From 1958 to 1968, residents in this area were not allowed to have children.

　　　　直到1978年，污染区还有20%的地方未能恢复生产活动。

　　　　1989年2月，即核事故发生后32年，苏联政府向国际原子能机构(IAEA)提供了有关该次事故的技术报告，终于将该次事故公布于众。其实，这是苏联政府迫于国内外舆论压力，不得已而为之。

　　　　苏联原计划在克什特姆镇邻近处建立一座快中子反应堆，在先拉斯诺亚尔斯克建造世界上最大的核废物库。这项计划在苏联国内引起了激烈的争论和抗议。可能是因为针对这次反核风波，苏联官方才公布了乌拉尔核事故的有关资料。

　　　　5.太平洋进行核试验：比基尼事件

　　　　1954年3月1日凌晨时分，位于太平洋比基尼环礁约160公里的公海上，日本“第5福龙丸”号渔船正在航行。此时在比基尼环礁上进行了氢弹核试验，天亮之前，天空被照得很亮，不久有烟柱升起。两个小时后，“福龙丸”的船员发现船上散落了大量氢弹爆炸后的灰，他们没有意识到，飘散到他们船上的，是具有辐射作用、可以对人体造成伤害的“死亡之灰”。

　　　　1954年3月14日，“福龙丸”回港后有关部门对船员们带回的“爆炸后落灰”进行了分析，才知道是美国研制的新型氢弹，美国正在研制秘密武器和进行核武器开发的事实因此被曝光。

　　　　At that time, there were 23 crew members on the "Fulong Maru", and all the crew members were immediately sent to Tokyo for treatment. But unfortunately, six months later, Kuboyama Aji, the oldest person in charge of communication on board, died at the age of 40.

　　　　It was reported afterwards that the United States secretly conducted the largest hydrogen bomb explosion test in history on bikini atoll. According to scientists’ analysis, the destructive power of this hydrogen bomb is no less than the atomic bomb dropped by the United States in Hiroshima that year, and it is conservatively estimated that the power is at least 1000 times higher. The test caused nuclear pollution, and the crew on the No.5 Fulong Pill was one of the victims. This incident is called "bikini incident" in Japan.

　　　　In August 1945, after the United States dropped the first atomic bomb on Hiroshima, Japan, the Soviet Union began to accelerate the development of atomic bombs. In 1949, the first atomic bomb of the Soviet Union was successfully tested. The news spread to the United States, causing shock and anxiety in the United States. The military hegemony of the United States was challenged, so the United States began to develop a more powerful nuclear weapon-the hydrogen bomb, and a series of nuclear tests were necessary to develop this terrible weapon. In January 1946, after repeated deliberation and investigation, the US Atomic Energy Commission finally selected the Marshall Islands in the Pacific Ocean as a new atomic bomb testing ground. The Marshall Islands has become an innocent victim of these nuclear tests.

　　　　The Marshall Islands is located in the middle of the Pacific Ocean, with a land area of 181 square kilometers. It consists of more than 1,200 Okojima reefs, which are distributed in the sea area of more than 2 million square kilometers. In February 1946, the United States forced the local residents to move, and American engineers entered bikini atoll and conducted a hateful hydrogen bomb test. Although the Marshallese did not want to leave their ancestral homes, they had to move to another island 200 kilometers away in tears under the threat of American naval guns and tanks. What is even more vicious is that the US military did not tell the residents the reasons for the relocation and the possible harm caused by the nuclear test, which ultimately made the local residents pay a heavy price.

　　　　In the early morning of November 1, 1952, the world’s first hydrogen bomb "Mike" was detonated here. In an instant, nuclear radiation, shock wave, and optical radiation 500 times stronger than the atomic bomb dropped on Hiroshima … brazenly flaunted over the Pacific Ocean. Researchers who observed the explosion of hydrogen bombs 60 kilometers away humorously described that the world’s first man-made thermonuclear sun rose.

　　　　The success of the test explosion of the hydrogen bomb has enabled the United States to regain its dominant position in the field of nuclear weapons, and its mind has been a little down-to-earth, thinking that it can rest easy and sleep comfortably. But they forget that a sly rabbit should have three caves, and only one is not enough. In August 1953, the first hydrogen bomb in the Soviet Union was successfully tested, which deeply hurt the United States, so the United States decided to explode a more powerful hydrogen bomb, and the real nightmare of the Marshallese came.

　　　　The two countries are fighting like two children. On March 1, 1954, the United States placed a hydrogen bomb predicted to be 6 million tons of TNT equivalent in Bikini Atoll, Marshall Islands. At about 6: 45, the hydrogen bomb exploded about two meters above the ground. The explosion scene quickly dumbfounded the observers: this can never be an explosion equivalent of 6 million tons! Because they found that the island where the hydrogen bomb was located and two nearby islands disappeared from sight at the moment of explosion. The U.S. air observation plane found that the place where the hydrogen bomb was originally placed suddenly became a deep lake. The Great Lakes are nearly 2 kilometers wide and 80 meters deep. People can clearly see the light on the island 220 kilometers away from the explosion center.

　　　　Due to the failure to estimate the explosive power, the U.S. military failed to inform nearby residents and fishing boats of various countries operating at sea to evacuate in advance, which caused the biggest nuclear pollution incident in the Pacific Ocean.

　　　　(Reader Sun Guangxing is excerpted from The 5000-year Disaster Record of the World I Must Know, published by Wuhan Publishing House, priced at 28.00 yuan)

　　The Central Economic Work Conference clearly pointed out that it is necessary to correctly understand and grasp the characteristics and behavior laws of capital. As an important factor of production, a correct understanding and grasp of the characteristics and behavior laws of capital will not only help capital to play a greater, better and more effective role under the socialist system, but also be an inevitable requirement for accelerating the improvement of Socialism with Chinese characteristics’s market economy theory and practice. From the formation background and function mode of capital, the duality that runs through all social production links, such as production, distribution, circulation, consumption and competition, is the fundamental characteristic of capital. To correctly understand and grasp the behavior law of capital should be based on giving full play to the enthusiasm of capital in the five major links and restraining its negativity.

　　From the production link, the expansion of capital has duality, which can not only promote economic growth, but also curb the potential of economic growth.On the one hand, the expansion of capital is an important driving force to improve the level of productivity and promote economic growth. Because it is closely related to the birth and outbreak of the industrial revolution, the capitalist system plays an irreplaceable role in stimulating the enthusiasm of the whole society for production. The fundamental reason for this phenomenon is the large-scale and rapid expansion of capital driven by profit targets, which has greatly released the productivity of the whole society. On the other hand, due to the profit-seeking nature of capital, the expansion of capital in real economic activities is often disordered and over-expanded, which directly leads to the over-commercialization of a large number of industries involving basic people’s livelihood. For example, industries such as medical care, education and old-age care should be public welfare industries in which the government plays a leading role, and their functional orientation is to serve and meet the basic life and development needs of ordinary residents. However, driven by the interests of over-expansion of capital, the functional orientation of these industries to serve the people is alienated to improve economic efficiency as the primary goal. In the long run, the living and production costs of the whole country will greatly increase, and the residents’ happiness will not only decline rapidly, but also the sustainable development potential of the whole country will face a huge impact.

　　From the distribution link, the composition of capital has duality, which not only helps to make a big "cake", but also hinders the reasonable division of "cake"From the material form, capital consists of a certain number of means of production and labor, while from the value form, capital consists of a certain number of constant capital and variable capital, the former is the technical composition of capital and the latter is the value composition. Marx called this relationship between the value composition of capital, which is determined by the composition of capital technology and reflects the change of the composition of capital technology, the organic composition of capital. In the specific production process, in order to pursue as many profits as possible and save themselves and beat their opponents in the fierce competition, capitalists always try their best to improve production technology and adopt new production equipment, which makes the constant capital proportion and organic composition of capital representing technology and equipment show a rising trend, and the production efficiency and final total output will also increase accordingly, which is an important way to make a big cake. However, the increase in the proportion of constant capital means that the substitution effect of machines on labor is enhanced, the overall demand for labor in the production process is gradually decreasing, the dominant position of capital elements in the "cake" link will become stronger and stronger, and the income share of capital elements and labor elements will gradually increase, which will eventually lead to a huge gap between the rich and the poor. As Picchetti put forward in Capital in the 21st Century, because the rate of return of capital factors is higher than the economic growth rate, the free market economy-oriented distribution system will lead to a solidified gap between the rich and the poor. It can be seen that the improvement of the organic composition of capital will not only enlarge the "cake", but also make the share of "cake" tilt to the capital elements and lead to the widening income gap.

　　From the point of circulation, the turnover of capital has duality, which not only helps to expedite the circulation of the economic system, but also leads to excessive virtualization of the real economy.According to Marx’s capital turnover theory, one of the important factors that determine capital profit is the length of production cycle. The longer the production cycle, the longer it takes for capital to complete a single cycle, and the lower the number of cycles that can be realized and the total profit obtained within a fixed period. In this context, capital will reduce the production cycle time by continuously expanding the spatial scope of industrial cooperation, improving the division of labor in different sectors of the industry, and adopting advanced production technology and transportation technology, so as to complete more cycles and obtain more total profits. However, from the essence of capital turnover, the above means can not reduce the production cycle time indefinitely. The fundamental reason is that the decisive factor that determines the length of production cycle time is the proportion of production capital: if the proportion of working objects such as raw materials, fuels and auxiliary materials and working capital used to buy labor force is large in all capital, the production cycle speed will be fast; On the other hand, if the fixed capital ratio used to purchase labor materials such as factories, machines, equipment and tools is significant, the speed of production cycle will be slow. In this context, if capital enters the real industry that needs to invest a lot of fixed capital, no matter what cooperation, division of labor mode and production technology are adopted, compared with the virtual economy industry that hardly depends on fixed capital investment, the number of cycles it can complete and the total profit it gets will be less than that of the virtual economy industry under the same conditions. Therefore, in order to get more profits faster,Of course, we will continue to take effective measures to break the obstruction of the economic system and speed up the economic production cycle, thus reducing the production cycle time. However, the restriction of fixed capital on the decline space of production cycle time will eventually induce capital to choose the development path of "deviating from reality to emptiness"

　　From the consumption link, the accumulation of capital has duality, which will not only provide a class foundation for the popularization of new products, but also inhibit the overall consumption because of reducing the income of most people.In the normal production process, because capitalists can occupy the surplus value created by labor for free and will not put all the surplus value into expanded reproduction, this means that capitalists can easily become the "rich first" class in the whole society. From the historical experience and reality, these groups often play an important role in leading and demonstrating the popularization of new products, which is one of the important power sources of overall consumption. However, because the fundamental purpose of capital accumulation is to grab more surplus value by expanding reproduction, in the context of fierce market competition, capitalists will not only continue to put most of the surplus value obtained into the process of social reproduction, but also improve the organic composition of capital by adopting new technology and equipment, which will make the demand of capital for labor force and the normal wage level of labor force face tremendous downward pressure. It can be seen that although capitalists can ensure or even greatly improve their consumption power by seizing surplus value, the fundamental purpose of capital accumulation and the specific realization path determine that the labor group as the main class of society will fall into the predicament of insufficient income. Obviously, in this case, the consumption promotion share of the capitalists in the absolute minority is not enough to offset the consumption decline share of the workers in the absolute majority, and the consumption scale of the whole society will face the risk of continuous shrinkage and long-term shortage.

　　From the point of view of competition, the concentration of capital has duality, which not only contributes to the perfection of the market economy system, but also leads to a highly monopolistic competition pattern.Different from the process that the growth of a single capital depends on capital accumulation, capital concentration is formed in the competition process of multiple capitals. Through fierce market competition, the capital with higher production efficiency will become bigger and stronger by defeating and annexing the capital with lower production efficiency, while the small and medium-sized capital in a disadvantaged position will jointly fight against the big capital through credit tools. Therefore, in the process of continuous and repeated competition between large and small capitals, fair market competition rules and sound market credit environment will be gradually established and improved, and the institutional system of market economy will become increasingly mature. However, capital concentration will not only occur within the same industry, but also between different industries, which means that big capital will not only pursue the absolute monopoly position within the industry, but even try to achieve monopoly on all industries. Just as Marx pointed out: "In a society, only when the total social capital is merged into the hands of the sole capitalist or the sole capitalist company can concentration reach its limit." Therefore, both the above theoretical analysis and the highly monopolistic competition strategy of big capital in the real world prove that this centralized orientation of capital will distort the market economy pattern of fair competition.

　　Facing the duality that capital runs through all social production links such as production, distribution, circulation, consumption and competition, the general principle should adhere to the principle of "using its advantages and eliminating its disadvantages", and effectively control its negative effects while exerting its positive role as a production factor. Specifically, in the production process, it is necessary to clarify the clear boundary between the government and the market, give capital a high degree of autonomy in the field where the market plays a decisive role, and at the same time set up "traffic lights" for capital to prevent excessive expansion of capital into the people’s livelihood industry; In the distribution link, we should not only encourage the timely and extensive application of advanced technology and equipment, but also speed up the improvement of the minimum wage system, wage growth system and social security system to ensure that the distribution gap of different types of elements can be controlled within a reasonable range; From the point of circulation, it is necessary to speed up the improvement of the tax structure, reduce the tax burden of the real economy, and balance the profit relationship between the real economy and the virtual economy. At the same time, it is necessary to consciously guide and plan the spatial ladder layout of the real industry to avoid the premature and common phenomenon of "deviating from reality to emptiness"; From the consumption link, we should not only allow and encourage the owners of capital elements to lead consumption, but also unswervingly promote the income multiplication plan of middle-income groups, the strategy of expanding domestic demand, and the strategy of housing and not speculating, so as to cultivate healthier domestic demand motivation; From the aspect of competition, we should not only allow and respect the reasonable competition of capital in the market, but also strengthen the effective supervision of capital according to law to prevent capital from choosing the barbaric growth mode of "monopoly for monopoly’s sake".

　　In a word, capital is not the decisive factor to distinguish the socialist system from the capitalist system, but the specific path and final effect of capital will still have an important impact on the quality and success of national development. Therefore, in the process of adhering to and perfecting Socialism with Chinese characteristics’s market economy theory and system, we should fully understand and grasp the duality of capital and guide capital to play a more active, effective and reasonable role.

　　China news agency, Beijing, January 18 (Reporter Li Jingze) The press conference of "Blue Book of China Aerospace Science and Technology Activities (2022)" was held in Beijing on January 18. The reporter learned from the press conference that in 2023, the mission of China Space Station will launch Shenzhou 16 and Shenzhou 17 manned spacecraft and Tianzhou 6 cargo spacecraft.

　　Jing Zheng, deputy commander-in-chief of the space station system of the Fifth Academy of China Aerospace Science and Technology Corporation, said at the press conference that in 2023, the crew of Shenzhou 15 and Shenzhou 16 will stay continuously, carry out astronauts and cargo extravehicular activities, support space science, materials and technology test projects, and carry out maintenance and technical upgrading of space station facilities and equipment. Among them, the extravehicular load support under the cascade state of large and small manipulator will be carried out for the first time, the small manipulator will be installed for the first time, and people and goods will be released from the cabin at the same time for the first time.

　　In terms of manned spacecraft, Kevin·Z, deputy chief designer of the manned spacecraft system of the Fifth Academy of China Aerospace Science and Technology Corporation, said that in 2023, the manned spacecraft will carry out two returns, two rendezvous and docking, and Mifune emergency support as planned, involving four shenzhou spaceship ships from Shenzhou 15 to Shenzhou 18. At the same time, the follow-up spacecraft will be developed in parallel. In 2023, the manned spacecraft mission will maintain a high-density and multi-ship parallel development state, and launching a manned spacecraft every six months will become the norm.

　　As for the cargo spacecraft, Xu Xiaoping, deputy chief designer of the cargo spacecraft system of the Fifth Academy of China Aerospace Science and Technology Corporation, said that the Tianzhou-6 cargo spacecraft will be launched in 2023, which will transport the living materials, crew equipment and resident consumption for the Shenzhou-16 crew and the Shenzhou-17 crew, supply propellant for the space station, spare parts for the uplink maintenance and air cylinders for the cabin, etc., which will be the equipment and consumption materials for the on-orbit uplink application test.

　　He pointed out that the Tianzhou-6 cargo spacecraft is an improved spacecraft, which has expanded the volume of the sealed cabin and increased the cargo transportation capacity. It is still launched into orbit by the Long March 7 rocket at the Wenchang launch site in Hainan. (End)

　　Zhao Fangchen, a researcher at Nanjing Institute of Geology and Paleontology, Chinese Academy of Sciences, shows the primitive vertebrate Yunnan insect fossils. Photo courtesy of Xinhua News Agency reporter Luo Boshe/vision china

　　Yang Dinghua Drawing of Ecological Restoration Map of Yunnan Insects

　　The research team analyzed the branchial arch structure of 127 specimens of Yunnan worms produced in Haikou area, and found the three-dimensional preserved laminated disk cell structure and protein microfibril structure in the pharyngeal arch of Yunnan worms for the first time. This proves that Yunnan worm has a unique pharyngeal arch composed of cellular cartilage in vertebrates and belongs to primitive vertebrates.

　　Where did modern vertebrates come from? What does the oldest vertebrate look like? These major scientific problems have always attracted paleontologists to explore.

　　Chengjiang Fauna, located in Yunnan, China, has preserved a large number of ancestral groups of vertebrates.

　　Previously, it was generally believed that the oldest vertebrate was Kunming fish from Chengjiang fauna, and it was speculated that the ancestors of vertebrates were a kind of retrognathus with notochord, dorsal neural tube and branchial fissure. However, this hypothesis has never been supported by fossil evidence.

　　Today, this mystery has finally been solved.

　　On July 8th, Science, an international authoritative academic journal, published "The Earth — The research results of the team "Early Evolution of Life System" confirmed that Yunnan worm in Chengjiang fauna in China was the most primitive group of vertebrates 518 million years ago.

　　The definition of Yunnan insect identity was once controversial.

　　The Burgess shale fauna in Canada about 505 million years ago and the Chengjiang fauna in China about 518 million years ago are rich and beautifully preserved animal fossils characterized by soft body structure.

　　Among them, Burgess shale fauna discovered in 1909 produced cephalochordate pickup fish and vertebrate post-Sprigg fish fossils, while scientists found many chordate fossils in Chengjiang fauna, including vertebrate Kunming fish and Yunnan worm with doubtful taxonomic position. These fossils are the oldest chordates in the world so far, providing valuable materials for uncovering the mystery of the origin and early evolution of vertebrates.

　　From the morphological point of view, Yunnan worms are somewhat similar to the current worms. Their bodies are flat on their sides, generally only 3 cm to 4 cm long.

　　"Different from Kunming fish with typical vertebrate characteristics, Yunnan insect is more similar to amphioxus, but its position in the origin of vertebrates and the phylogenetic tree of metazoa has always been controversial. Jiang Baoyu, the co-author of the paper and a professor at Nanjing University, introduced it.

　　In 1995, Nature published a study on Yunnan worm as the earliest chordate. The New York Times and Science Weekly also made special comments on it.

　　After that, China scholar Chen Junyuan and others found a large number of new specimens of Yunnan worms in Haikou, Kunming. Based on the finer anatomical structure of these specimens, they classified Yunnan worms as primitive cephalopods and thought that their evolutionary position was between amphioxus and lamprey, a vertebrate. After this achievement was published in Nature in 1999, there was a great discussion about the taxonomic position of Yunnan insects in academic circles.

　　"Because different scholars have different explanations on the details of different soft tissues preserved by Yunnan worms, Yunnan worms have been classified into vertebrates, cephalochordates, hemichordates, faunas and even primitive bilaterally symmetrical animals since they were first reported in 1991." Jiang Baoyu introduced that the controversy over the taxonomic position of Yunnan insects has seriously affected the research on the origin of vertebrates based on such key fossils.

　　The special characteristics of pharyngeal arch help it to verify its true identity

　　In view of the mystery of the taxonomic position of Yunnan insects, the research team used various modern experimental techniques such as three-dimensional X-ray scanning microscope, Fourier infrared spectrum, Raman spectrum, scanning electron microscope and transmission electron microscope to study, hoping to solve this puzzle from the microscopic anatomical structure.

　　Based on the important clue put forward by Chen Junyuan and other scholars in 2003 that the branchial arch of Yunnan worms may have cytocartilage, the research team analyzed the branchial arch structure of 127 specimens of Yunnan worms produced in Haikou area, and found the laminated disk-like cell structure and protein microfibril structure preserved in three dimensions in Yunnan worms’ pharyngeal arch for the first time.

　　"The discoid cell structure is a unique arrangement of chondrocytes, and protein microfibril is the fiber structure of the common intercellular matrix of vertebrate cartilage. These two characteristics prove that Yunnan worm has a unique pharyngeal arch composed of cytocartilage in vertebrates, indicating that Yunnan worm belongs to primitive vertebrates. " Jiang Baoyu said.

　　In order to further determine the specific evolutionary position of Yunnan insects, the research team integrated the latest character matrix including the fossils of the faunas and early vertebrates, and added the newly observed characters of Yunnan insects, and used Bayesian algorithm for reconstruction calculation. The analysis results support that Yunnan worm is in the most basic position of vertebrate pedigree, which is between caudate and other vertebrates.

　　"The origin of vertebrate jaws has also puzzled the academic community for a long time. At the beginning of the 19th century, some scientists put forward the idea that in the long evolution, the branchial arch evolved into the jaw arch and the tongue arch, but no fossil record was found to support it. " Jiang Baoyu introduced that the subsequent scientific discovery made people question this hypothesis.

　　"The genes controlling the first two branchial arches of the living jawless vertebrates, the blind eel and the lamprey, did not develop into the jaw arch and the tongue arch, but developed into the upper and lower lips, and no trace of the branchial arch was seen during the development, which is different from the branchial arch of the jawed vertebrates." Jiang Baoyu said that in this study, after confirming the "identity" of Yunnan worm, the researchers found the same laminated cell structure, gill filaments and protein microfibrils as other branchial arches in the back at the position equivalent to the first pair of pharyngeal arches.

　　Therefore, Yunnan worm has seven pairs of pharyngeal arches which are similar to each other from front to back and also have cytocartilage. Similar pharyngeal arches also appeared in another Cambrian backbone vertebrate — — After Sprigg fish.

　　"The discovery of seven pairs of similar pharyngeal arches of Yunnan insects supports the hypothesis of homology of vertebrate pharyngeal arches put forward by anatomists as early as the 19th century, that is, the gill arch of fish is the prototype of jaw arch and tongue arch, and the jaw arch and tongue arch of vertebrate are a series of homologous structures." Jiang Baoyu said that this means that although the pharyngeal arches in different positions of living vertebrates will develop into bones with different shapes such as jaw arch, tongue arch and gill arch, the pharyngeal arches in different positions in the early stage of vertebrate evolution are similar to each other.

　　Basilar pharyngeal cranium confirms the morphology of vertebrate ancestors’ pharyngeal cranium

　　Jiang Baoyu believes that another important new discovery of this study is that seven pairs of pharyngeal arches of Yunnan worm are connected by paired horizontal cartilage at both ends of the ventral back, forming a basket-like pharyngeal skull. Pharyngeal cranium refers to a group of bone fragments around the digestive tract of vertebrate head, which plays a supporting and protecting role. The pharyngeal cranium of living vertebrates is composed of the bones of pharyngeal arch such as jaw arch, tongue arch and branchial arch.

　　"Basket-shaped pharyngeal cranium is a typical feature of modern jaw-less vertebrates and fossil jaw-less fish. However, after Cambrian, the pharyngeal cranium of Sprigg fish and jaw-less vertebrates consists of a series of cartilage rods separated from each other." Jiang Baoyu said that this feature of the post-Sprigg fish caused controversy about the morphology of the pharynx and cranium of vertebrate ancestors. The early appearance of the pharyngeal cranium features of Yunnan insects located in the most basic position of vertebrates supports the view that the basket-shaped pharyngeal cranium is an older ancestral feature.

　　It can be seen that as the oldest close relative of living vertebrates, Yunnan worm provides key evidence for revealing the origin and early evolution of vertebrates, and will have a far-reaching impact on the exploration of the evolution of vertebrates’ jaws and other key features.

　　Jiang Baoyu believes that "from another perspective, this study once again shows that Chengjiang fauna fossils have the potential to preserve micro-nano scale fine biological structures."

　　This achievement has also been highly praised by the reviewers of Science magazine: "This is a great contribution to science, and this paper will become a key paper in vertebrate paleontology, showing the long-awaited and most credible evidence of anatomical structure fossils and solving the controversy of vertebrates in Cambrian. The information they show is a milestone, and even higher-resolution research will be difficult to surpass in many years to come. "