Source: Xinhua Net
Xinhua News Agency, Xi'an, February 10 Title: Big Country "Bell" Smith -- Remembering Zhang Shougang, Chief Scientist of the National Timing Center of the Chinese Academy of Sciences, and His "Time Team"
Xinhua News Agency reporters Zhang Boda and Zheng Xin
The generation, retention, and transmission of time information in a certain way is called "timing." Since the 1960s, generations of mainland teachers have taken root in the Great Northwest, sat on the cold bench, and innovated and strengthened themselves, creating a precise "Chinese time". - Caption
On February 8, Zhang Shougang, chief scientist of the National Timing Center of the Chinese Academy of Sciences, worked in the Space Light Clock Laboratory. Photo by Xinhua News Agency reporter Zhang Bowen
On February 8, Zhang Shougang (middle), chief scientist of the National Timing Center of the Chinese Academy of Sciences, communicated with members of the scientific research team at the Space Narrow LineWidth Laser Laboratory. Photo by Xinhua News Agency reporter Zhang Bowen
In the Lintong District of Xi'an City, where the world-famous Terracotta Warriors and Horses of Qin Shi Huang are located, the subway from the main city of Xi'an from west to east turns north at an almost right angle after arriving at Huaqingchi Station.
Part of the reason is to avoid the National Timing Center of the Chinese Academy of Sciences, about two kilometers to the east, so as not to potentially affect China's national standard time, Beijing time, which is generated and maintained from here.
At the beginning of the establishment of the Shaanxi Astronomical Observatory, the predecessor of the Chinese Academy of Sciences, the National Timing Center of the Chinese Academy of Sciences was mainly established to meet the urgent needs of national defense and economic construction. Today, Zhang Shougang, director of the National Timing Center of the Chinese Academy of Sciences and chief scientist, and his "time team" have achieved a number of key core technology breakthroughs, reducing the deviation between mainland standard time and international standard time from 100 nanoseconds to 5 nanoseconds, making its overall performance rank among the top in the world, and engraving national interests into the "Sea of Stars".
Determined to build the "Great Bell of China"
Zhang Shougang (left), chief scientist of the National Timing Center of the Chinese Academy of Sciences, works at the Cesium Fountain Clock Laboratory on February 8. Photo by Xinhua News Agency reporter Zhang Bowen
Under the mezzanine of Zhang Shougang's desk is a white T-shirt printed with a barrel-shaped precision device.
"The T-shirt was custom-made for me by my colleagues when I graduated from the Paris Observatory in France. The device on the screen is the world's first cesium atom fountain clock that I participated in the transformation. He said.
Among the seven basic physical quantities of the International System of Units, time is the one with the highest measurement accuracy and the most wide application. In 1967, in order to improve the accuracy of time measurement, the 13th International Conference on Metrology revised the definition of the time unit "second" to reflect the astronomical time "second" of the earth's rotation state to the atomic time "second" timed by the electromagnetic oscillation period inside the atom. Since then, some physicists have worked hard to develop an atomic clock related to the generation and maintenance of time, that is, the atomic frequency standard (frequency scale), which is not only a strategic resource for the advancement of a country's time and frequency science, but also a manifestation of national sovereignty.
Physicist Wang Yichen, a former executive vice president of Peking University, once said: "In the era of precision strikes, atomic clocks play no less than atomic bombs. ”
On February 7, researchers discussed the progress of the project at the Space Strontium Atomic Light Clock Laboratory of the National Timing Center of the Chinese Academy of Sciences. Photo by Xinhua News Agency reporter Zhang Bowen
"In 1998, after visiting China, a well-known physicist from a Western country said that the experimental study of atomic clocks in China relied on 'luck'. I learned this sentence in small talk with other researchers in the laboratory, and I was deeply stimulated to make an atomic clock with a long Chinese ambition. Zhang Shougang said.
In 2005, Zhang Shougang left Beijing after returning from overseas studies and came to the National Timing Center in Lintong District, Xi'an City, to preside over the research and development of atomic clocks and standard time research.
"At that time, the small cesium clock used by the National Timing Center for punctuality was completely imported, and there was no benchmark cesium atomic fountain clock, and even the relevant research and development equipment and researchers did not have it." According to Guo Wenge, a university alumnus of Zhang Shougang and a researcher at the National Timing Center who returned to China almost at the same time, it was under such conditions that Zhang Shougang started from a person, from a basement of the unit, from a screwdriver, to build a platform and recruit talents.
Nowadays, the Quantum Frequency Standard Research Laboratory of the National Timing Center he established has nearly 100 young and middle-aged researchers, and has developed into a key laboratory of the Chinese Academy of Sciences; not only has independently developed the international advanced benchmark cesium atomic fountain clock, but also realized the productization of punctual light pumping small cesium clocks in 2018.
Widely used portable small cesium clock products, the previous 50 years have been monopolized by the United States exclusively. In 2017, small cesium clock products were banned in China.
Nowadays, this domestic small cesium clock has not only been applied to tasks such as beidou satellite navigation system, Yangtze River II navigation system, 5G communication system and Arctic scientific expedition, but also equipped with a national standard time generation and retention system. In November 2021, three domestically produced cesium clocks gained contribution weight in the calculation of international standard time and were recommended by the International Bureau of Rights to countries for the generation of standard time.
"The foreign scientist who said China relies on 'luck' met me at an annual academic conference in 2019 expressed his admiration for China's achievements in the field of time and frequency." Zhang Shougang said.
Dedication Continue the responsibility and responsibility of the red bloodline
On February 8, researchers recorded data at the Time frequency reference laboratory of the National Timing Center of the Chinese Academy of Sciences. Photo by Xinhua News Agency reporter Zhang Bowen
The same T-shirt as Zhang Shougang's was kept in his office for several years, and there were four bottles of champagne. He had brought it back from France, and it was originally intended to celebrate with everyone after a major breakthrough.
But until now, even if they have made more scientific breakthroughs, the celebration wine has not been unsealed. Zhang Shougang said that it is not that there is no merit to celebrate, but that the time-giver has a dial in their hearts: in the never-ending pursuit of accuracy and stability performance, every time the end point is paid, it will become a new starting point.
In modern China, the generation and transmission of standard time has long been dominated and controlled by foreigners. After the founding of New China, with the start of large-scale national defense and economic construction, it was urgent to build a timing platform in a hidden place in the hinterland of the inland.
Under the care of Premier Zhou Enlai, the Shaanxi Observatory in Pucheng County, Shaanxi Province, was established in 1966 and opened shortwave timing in 1971.
Many of the scientists and young college students who participated in the creation of the Shaanxi Astronomical Observatory came from Beijing, Shanghai, Nanjing and other major cities. Qi Guanrong, who was once the director of the Shaanxi Observatory, recalled that when he had just graduated from Nanjing University, he and the first batch of more than a dozen other young people got off the train and turned to the car, got out of the car and walked to the foot of Jinzhi Mountain in Pucheng County, which was far from the crowds.
Recalling the barren construction site in front of him at that time, Qi Guanrong said: "Even if you move stones, you must build the observatory with your hands!" ”
The completion of the short-wave timing platform has enabled the mainland to have the land-based radio timing capability with full coverage of the country, and has opened a new page in China's timing. On this basis, the long-wave timing station low-power test station was piloted in July 1976, and four months later, the signal was officially broadcast regularly every day.
"Engage in a national bell ... It is not only important for cutting-edge technology, but also for the development of the natural sciences of the mainland and even the whole science. Qian Xuesen once described the significance of the long-wave timing platform in this way.
The completion of the long-wave timing system has allowed China to catch up with the pace of the world. This achievement also won the first prize of the National Science and Technology Progress Award in 1988.
This is the Beijing time monitoring system of the Time Frequency Reference Laboratory of the National Timing Center of the Chinese Academy of Sciences (taken on February 7). Photo by Xinhua News Agency reporter Zhang Bowen
In the construction of an independent timing system, a number of middle-aged and young scientific and technological workers have taken root in the western region and served the country with science and technology. In order to further adapt to the national requirements for timing work, the Shaanxi Astronomical Observatory moved to Lintong in 1980 and was renamed the National Timing Center of the Chinese Academy of Sciences in 2001. Although the address and name have changed, the original intention has not changed, and the time-givers of the new era continue to have a red blood and are obsessed with research and dedication.
Atomic clocks are the crystallization of cutting-edge theories and cutting-edge technologies, and it is the norm to make an atomic clock in ten years or more.
Sometimes the suffering of the time-giver is not just the suffering of the body: some are sedentary and suffer from lumbar disc herniation and do not have time to go to surgery, some have ankle bone fractures and jump into the laboratory during the Spring Festival holiday with plaster casts; but more often, it is the pain of sitting on the cold bench with hundreds of components and instruments.
The light clock is a forward-looking atomic clock, and Chang Hong, a researcher at the National Timing Center, is responsible for the development of the strontium atomic light clock. In the critical stage of scientific research, as the only son in the family, he experienced the death of his parents due to illness, of which his father had been paralyzed for six years before his death. "I used to be most afraid of receiving a phone call at night, saying that the elderly at home had a situation."
But he said that in this strategic highland that the whole world is staring at, the window of time is only one or two years to seize it. The state's plan cannot be delayed here, and no matter how difficult it is, it must grit its teeth and push the research down.
"Clock making is a cause worth paying for a lifetime, because this is the strategic need of the country; making a clock is also a lifelong undertaking, because the development and progress of all walks of life has endless requirements for the performance of atomic clocks, including the convenience of use." Zhang Shougang said.
In the 31 years since he has been in this business, he has led the development of 9 new atomic clocks for different application types.
Innovation Continue to climb the world's scientific and technological peaks
On February 8, researchers worked at the Space Strontium Atomic Light Clock Laboratory at the National Timing Center of the Chinese Academy of Sciences. Photo by Xinhua News Agency reporter Zhang Bowen
The effective operation of communication, power, finance, navigation and other systems that pulse economic and social development depends on high-precision time synchronization. With the development of society and the progress of science and technology, the timing system is not only a public welfare project related to the national economy and people's livelihood, but also a strategic heavy weapon related to national security.
In 2003, in order to meet the major urgent needs of the country, the National Timing Center and related research institutes relied on the accumulation of time frequency technology and astronomical science theory to develop and build the China Regional Positioning System (CAPS) demonstration and verification system in less than three years, with the accuracy of the US GPS satellite navigation system.
"The construction of the CAPS system reflects the spirit of 'courage to innovate' and is still inspiring the new era of timemakers to move forward." Dou Zhong, secretary of the Party Committee of the National Timing Center of the Chinese Academy of Sciences, said that innovation is the first driving force leading scientific and technological progress. Since the Eighteenth National Congress of the Communist Party of China, the National Timing Center has adhered to independent innovation without stopping and taking fast steps, and strengthened the layout, strengthening the layout, strengthening and expanding in the areas of national strategy.
Sending a light clock with higher accuracy than a microwave atomic clock into space and achieving a high-precision space time reference is the forefront of the current world's scientific and technological development. Zhang Shougang and the team of more than a dozen young and middle-aged "bell smiths", with ten years to create the center's first ground light clock, now the work is to spread out more than 20 square meters of light clock into less than 1 cubic meter of space station experimental cabinet, the difficulty is not only the size of the device components to reduce, but also the system and process of reconstruction, the need to break through a series of key technologies. At present, this "gas clock" is stepping up its development at the National Timing Center.
"The National Timing Center has made great progress in time frequency research and timing work, and it is because of this group of lovely colleagues." Zhang Shougang said that "national people" do "national affairs" and "national teams" assume "national responsibilities", and the national timing center always puts national interests in the first place and is committed to filling one domestic gap after another:
-- Restart the independent measurement of this strategic resource of world time, get rid of the dependence of previous world time data on foreign countries, and ensure the smooth progress of continental space missions.
——Start the construction of a high-precision ground-based timing system, combine optical fiber timing with improved long-wave timing to form ground-based timing, and integrate with satellite timing to build a timing system integrating heaven and earth.
-- Develop network time transmission and application of new technologies, establish nodes in the cloud, establish a network timing system, and fill the lack of high-precision "Beijing time" in cyberspace.
……
"Wherever the national interest expands, our timing services follow." Zhang Shougang said that the time-giving people will continue the red blood, carry forward the spirit of "two bombs and one satellite" and the spirit of the older generation of scientists, adhere to independent innovation to lead high-quality development, and win greater achievements in the work of timing in the new era. (Participating reporters: Liang Aiping, Zhang Chenjun, Zhang Bowen)
On February 7, at the Space Strontium Atomic Light Clock Laboratory of the National Timing Center of the Chinese Academy of Sciences, measuring instruments displayed relevant experimental signals. Photo by Xinhua News Agency reporter Zhang Bowen