From the waste to be rebuilt at the time of the founding of New China, to the raised eyebrows of today's modern China. The great Chinese nation has gone through a long journey and has also ushered in today's fruitful results. When it comes to today's China, who doesn't give a thumbs up?
Tips: On October 1, 1949, 300,000 people in Beijing gathered in Tiananmen Square to hold a grand founding ceremony, announcing to the world the establishment of the Central People's Government of the People's Republic of China.
Heaven we have The Shenzhou spacecraft, we have the Jiaolong submersible into the sea, and we have the shield machine. Today, Xiaobian would like to talk with you about these three Chinese weapons.
Shenzhou spacecraft
Dongfanghong-1 satellite was the first artificial earth satellite launched by China, developed by the China Academy of Space Technology with Qian Xuesen as the first president, and launched at 21:35 on April 24, 1970. The successful launch of the satellite marks that China has become the fifth country in the world after the Soviet Union, the United States, France and Japan to independently develop and launch domestic satellites using homemade rockets. This ushered in a new era in China's aerospace history.
Tips: In 1970, the Dongfanghong-1 satellite was launched by the Long March 1 carrier rocket into an elliptical orbit with a perigee of 441 km, an apogee of 2368 km and an inclination of 68.44 degrees. The satellite carried out orbital monitoring and control and the broadcast of the music of "Dongfang Hong".
The Dongfanghong-1 satellite is still in space orbit. With the launch of one satellite after another, the development of China's space technology is changing with each passing day, and the dream of manned spaceflight has also been engraved into the blood of the sons and daughters of China.
In 1992, China made a development strategy to implement the "three-step" development strategy of manned spaceflight projects.
The first step is to launch unmanned and manned spacecraft, build a preliminary supporting experimental manned spacecraft project, and carry out space application experiments;
The second step is to break through the astronaut out-of-the-cabin activity technology and the rendezvous and docking technology of space vehicles, and launch a space laboratory with short-term manned care;
The third step is to build a permanent space laboratory to solve the problem of large-scale and long-term humane space applications.
The Shenzhou series of spacecraft carries the space dream of Chinese to set sail for space. The unmanned spacecraft launched by the Shenzhou 1 to 4 spacecraft to complete the manned space mission are basically the same as those of the manned spacecraft.
In October 2003, the Shenzhou 5 spacecraft carried out its first manned space mission, which was also the first manned space vehicle launched by China.
Tips: The Shenzhou 5 spacecraft consists of a propulsion module, an orbital module, a return module, and an additional segment. The head is a cylinder with a plane of about 6 square meters and can accommodate 3 astronauts. The Shenzhou V spacecraft also has an interface to dock with the space laboratory.
On October 16, 2003, Yang Liwei, China's first astronaut, returned to Earth safely from space on the return capsule of Shenzhou 5, which marked a major breakthrough in China's manned spaceflight project, and China became the third country to send humans into space after Russia and the United States. It also marks the completion of the first of the three steps.
Tips: On September 27, 2008, the Shenzhou 7 astronauts carried out the capsule activity, completed the first spacewalk Chinese, and released the companion satellite. The astronauts in the cabin had a space-to-earth call with the Beijing Flight Control Center.
In September 2008, Shenzhou 7 was successfully launched. In this manned space mission, the great feat of astronauts' out-of-the-cabin activities was completed, which also marked that China became the third country in the world to independently master the key technologies of astronauts' out-of-cabin activities.
The Shenzhou-8 spacecraft successfully realized the docking with Tiangong-1, which also marks that China has successfully broken through a series of key technologies such as space rendezvous and docking and assembly operation.
Tips: Before the launch of Shenzhou 8, Tiangong-1 downgraded to a near-circular orbit at an altitude of about 343 kilometers, waiting for rendezvous and docking. Within 2 days after shenzhou 8 was launched into orbit, the first rendezvous and docking with Tiangong 1 was completed, forming a combination.
Shenzhou 9 carried a number of astronauts, including China's first female astronaut. After its launch in June 2012, Shenzhou 9 achieved automatic rendezvous and docking with Sky 1, which was also the first manned space rendezvous and docking implemented in China.
Shenzhou X was launched in June 2013 and docked with Sky 1 after liftoff and conducted a brief manned test.
Tips: Tiangong-2 Tiangong 2 is the second target vehicle launched by China's manned space project and China's first manned space science experiment space laboratory with supplementary functions.
In October 2016, the Shenzhou 11 spacecraft and the Tiangong-2 automatic rendezvous and docking were successful. The two astronauts then entered Tiangong-2 from the Shenzhou 11 spacecraft to complete the established experimental plan.
Tips: Tianzhou-1, code-named "TZ", is the first cargo spacecraft independently developed by China, a ground logistics support system for cargo transportation to Tiangong-2, and the finale of the "second step" in the "three-step" strategic plan of China's manned spaceflight project.
At present, our country is firmly moving towards the third step of the goal. Zhang Wei, deputy director of the Space Application Engineering and Strategic Planning Research Office of the Chinese Academy of Sciences, said: "China's manned space industry will enter the stage of manned space station in 2020, and the Shenzhou series of manned spacecraft, the Tianzhou-1 cargo spacecraft, the core module Tianhe, and the experimental module Mengtian and Qingtian have been arrows on the string. By 2024, China's manned space station is expected to become the only space station in orbit in the world. ”
Tips: The construction of a large space station is the third step of China's three-step strategy for manned spaceflight, and at this stage China will master technologies such as space assembly in low-Earth orbit and long-term manned presence in low-Earth orbit.
From Shenzhou 1 to Shenzhou 11, to more flying plans in the future, Chinese step by step out of our own space dreams, and use their own hard work and sweat to make their dreams come true. In the foreseeable future, we will also witness the record of new innovation in China's aerospace industry and bear more fruits.
EPB machines
The construction of the subway first requires the excavation of tunnels underground, which is not an easy task, and the investment in time and money is not small.
China adopted the most primitive manual excavation method in the early stage of tunnel construction. This method is time-consuming, laborious and inefficient. Subsequently, it gradually developed to a certain degree of mechanized operation, and it was not until the 1990s that the full use of shield machines began to carry out operations, and the degree of mechanization was greatly improved. To a certain extent, it has also boosted the development of China's subway construction.
Tips: A shield machine is a tunnel boring machine that uses the shield method. The construction method of shield tunnel is the "shield" (referring to the supporting segment) of the tunnel that the TBM builds (lays) at the same time as the tunneling, which is different from the open construction method.
The most common method now is to use a shield machine to carry out excavation, while excavating and installing pre-prepared components on the tunnel wall. As a special construction machinery for tunnel excavation, the shield machine can construct a shield body supporting the pit wall while excavating the underground tunnel, so as to realize the one-time molding of the tunnel. For places where buildings are highly dense, drilling is even the only viable method of tunneling.
According to the urban rail transit operation data express report released by the Ministry of Transport, by the end of 2020, in addition to Hong Kong, Macao and Taiwan, a total of 44 cities across the country have opened and operated urban rail transit lines, a total of 233, and an operating mileage of 7545.5 kilometers.
Tips: Beijing was the first city in Chinese mainland to open a subway. By the end of 2020, the Beijing subway will operate a total of 16 lines with an operating mileage of 525 kilometers.
According to the plan, during the 14th Five-Year Plan period, a new phase of subway construction will be launched in various localities, and the comprehensive development of TOD will also be rapidly promoted. When the construction of subways is in full swing throughout the country, shield machines are even more indispensable.
However, at the beginning, China did not have a shield machine, and could only be imported from abroad. The purchase cost of this equipment is very high, and in 1997, the price of a shield machine was as high as 300 million yuan. Until 2008, we relied entirely on imported equipment. At the same time, because the foreign party does not let us touch the technical drawings, and does not let us participate in the maintenance of the equipment, the efficiency of the use of the shield machine is completely controlled by people.
Tips: Transit-oriented development (TOD) is a non-automotive planning and design method that maximizes the use of public transportation when planning a residential or commercial area.
Under such circumstances, China has set up a research and development team on its own, adhering to the spirit of "there is no difficulty in the world, as long as you are willing to climb", and the development of key technologies for EPB shields is included in the "863" plan to overcome technical difficulties. In 2008, China's first composite shield machine with independent intellectual property rights was successfully rolled off the production line, and successfully completed the operation of the Tianjin Metro project.
Tips: The National High-Tech Research and Development Program (863 Program for short) is a major strategic deployment of the Communist Party of China to rejuvenate the country through science and education. In 2016, with the introduction of the national key research and development plan, the 863 program ended its historical mission.
China's infrastructure projects have finally escaped the control of foreign parties and achieved the goal of shield machines from scratch. In the following decade, China's shield machine industry also ushered in rapid development. With the advent of China's largest diameter EPB shield machine, China's largest diameter hard rock shield machine, and China's largest diameter slurry water balance shield machine, domestic shield machines have helped China become an "infrastructure demon".
Tips: "Chunfeng" has a diameter of 15.8 meters, jointly developed by China Railway Engineering Equipment Group and China Railway Tunnel Bureau Group, and is the largest diameter shield machine in China.
At present, China's independently developed shield machine can not only meet its own construction needs, but also because the manufacturing price of the equipment has been reduced by about 30%, and the inexpensive domestic shield machine has also won the favor of overseas customers. Orders are like snowflakes flying in, and the figure of domestic shield machines has appeared in the construction of subway projects in many Southeast Asian countries.
In just a few decades, China has realized the gorgeous transformation of shield machines from dependence on imports to independent research and development and finally become a big exporter of shield machines.
Jiaolong submersible
70% of the Earth's surface is ocean, and the area below 200 meters is the deep sea. Human footprints have already set foot on the lunar surface about 400,000 kilometers from Earth, but they are still in the relatively early stages of deep-sea exploration. Because in deep seas, high sea pressures, pitch-black environments and extreme temperatures are all challenges for exploration operations.
Tips: The deep sea area is dark all year round, the sun is difficult to penetrate, the salinity is high, the pressure is high, the water temperature is low and constant, the animal species and number are very poor, and most of them are detritus carnivores, with only a few carnivores.
But the oceans are an important part of the planet's entire ecosystem and are of great importance to us. The ocean is rich in flora and fauna, and they provide us with a rich source of food. The seabed is also rich in mineral resources, oil, natural gas, etc., providing more sources for our existing living and production materials.
Therefore, all countries are strengthening research and development on the oceans, especially in the deep-sea areas. In 2002, the Ministry of Science and Technology of China listed the development of deep-sea manned submersibles as a major special project of the National High-tech Research and Development Program (863 Program), and launched the self-design and independent integrated research and development of the "Jiaolong" manned deep submersible.
Tips: Marine mineral resources, also known as seabed mineral resources, include seashore, shallow sea, deep sea, ocean basin and mid-ocean ridge bottom of various mineral resources, such as oil, natural gas, coal and iron and other solid minerals and hydrothermal deposits.
From 2009 to 2012, jiaolong successfully dive to the 1000-meter class, 3000-meter class, 5000-meter class and 7000 meters. 7000 meters is an important node, indicating that the integration technology of Jiaolong manned submersible has matured, marking that the deep-sea submersible designed and manufactured by China has become the leader in the global marine scientific expedition equipment.
Theoretically, the "Jiaolong" manned deep submersible can be used in 99.8% of the world's sea areas, which is of great significance for China's development and utilization of deep-sea resources.
Tips: In June 2012, China's "Jiaolong" manned deep submersible set a Chinese manned deep diving record of 7,062 meters in the Mariana Trench, which is also the world's largest diving depth record for similar operating submersibles.
The success of the "Jiaolong" manned deep submersible marks that China has become the fifth country in the world after the United States, France, Russia and Japan to master large-depth manned deep diving technology. Moreover, among the known manned submersibles in the world, the technical level of "Jiaolong" is far ahead. At present, there are about 90 manned submersibles of various types in use in the world, of which only 12 dive to a depth of more than 1,000 meters, and the number of submersibles diving to deeper seas is even less. Countries with manned submersibles at depths above 6,000 meters currently include China, the United States, Japan, France and Russia.
epilogue
We are on solid earth, eager to understand this planet where human beings have lived for hundreds of years; we look at the endless ocean, hoping to establish new cognition and connection with the creatures of the deep sea; we also look up at the stars, want to understand the vast universe outside the earth, what surprises will bring us?
Tips: Tianwen-1 arrived near Mars in February 2021 to capture Mars. In May 2021, the opportunity was chosen to implement orbit reduction, the landing rover separated from the orbiter, soft landed on the surface of Mars, and the rover drove away from the landing platform to carry out inspection and exploration.
It is our curiosity and dreams that drive us to keep moving forward, and it is also the indomitable will and industrious and courageous quality of the Chinese people that push us from one victory to another.
Whether it is going to heaven and earth or going deep into the seabed, no difficulty can overwhelm the heroic Chinese people, we have done it, and we will do better in the future.