2020 was a year like no other. Marred by the COVID-19 pandemic, the pause button was hit due to lockdowns and other epidemic control measures, with the science and technology sector being no exception.

However, thanks to effective control of the epidemic in the country, and the perseverance and bravery of the scientific and technical personnel involved, China's sci-tech sector not only managed to live up to expectations, but also yielded astonishing results that have impressed the world.

Here we list China's top 10 scientific and technological accomplishments during 2020:

# Sci-tech contributes to triumphing over COVID-19

China's overcoming of the COVID-19 epidemic bears testimony again to the country's sci-tech capacity in disease prevention and control.

After detecting an outbreak in Wuhan, central China's Hubei province, Chinese scientists worked quickly to identify the unknown contagion as a novel coronavirus, sharing the whole genome sequence with the world at the earliest opportunity. This provided a solid basis for international scientists to develop diagnostic methods, new medicines and vaccines.

The Ministry of Science and Technology, together with the National Health Commission and other departments, jointly established an anti-virus research team consisting of 14 experts, and launched 16 emergency sci-tech projects offering support on virus tracking, testing kits, medicines and vaccine development. 

According to Dr. Bruce Aylward, team leader of the WHO-China joint mission on COVID-19, China "turbo-charged it (the response to the COVID-19 pandemic) with modern science and modern technology in a way that was unimaginable even a few years ago."

Meanwhile, China has adopted multiple technological approaches to reduce the timespan for developing COVID-19 vaccines. On Dec. 31, China announced it had granted conditional marketing authorization for a domestically developed vaccine.

# The mystery of China's prehistoric human population revealed

An article titled "Ancient DNA indicates human population shifts and admixture in northern and southern China" by the Chinese Academy of Sciences was published online in Science magazine this July, shedding light on China's prehistoric human population migration and admixture. 

The study sequenced DNA from 26 individuals who lived between 9,500 and 300 years ago from locations across China. Analysis of these individuals, along with previously sequenced ancient remains and present-day genomes representing global populations, show a split between ancient humans in northern and southern China. 

Neolithic individuals from northern China are closest to modern-day East Asians, whereas ancient southern Chinese individuals are most closely related to those from present-day Southeast Asia. These outcomes suggest that there was a southward movement and admixture of peoples during the Neolithic period that gave rise to modern-day populations in East Asia.

# China's Mars probe ready for the red planet

China's first Mars mission probe Tianwen-1 has traveled over 400 million km as of Jan. 3 and is expected to enter Mars orbit next month.

Since its launch on Jul. 23, 2020, the probe has traveled through space for 163 days as of Sunday, and is currently located 130 million km from Earth and around 8.3 million km from Mars.

Currently in a stable condition, the probe has captured an image showing both Earth and the moon, and has also taken several selfies. It has so far carried out three orbital corrections, a deep-space maneuver and conducted self-checks on its multiple payloads.

Consisting of an orbiter, lander and rover, the probe aims to complete orbiting, landing and roving in a single mission. This will represent a significant technological leap forward for China in deep space exploration and establish an independent deep-space exploration engineering system to promote sustainable development in this field.

# Construction of BeiDou Navigation Satellite System fully completed

China's self-constructed and independently operated BeiDou Navigation Satellite System (BDS) was officially put into service worldwide on Jul. 31, 2020, opening a new chapter in China's high-quality global navigation service.

On Jun. 23, China completed construction of the BDS with the launch of the system's final satellite, making the BDS China's largest space system with the broadest coverage, best service performance and closest connection with the lives of the people.

China began building the navigation system in the 1990s and has formulated a three-step development strategy. Construction of BDS-1 was completed in 2000, making China the third country in the world to own an independent global navigation satellite system. The deployment of the BDS-2 was finished in 2012, providing positioning, navigation and timing services to users across the Asia-Pacific region.

The 26-year journey of developing the BDS once again attests to the "Chinese speed and accuracy."

# Proposals adopted by the fifth plenary session of the 19th CPC Central Committee prioritize sci-tech development

The proposals for formulating the 14th Five-Year Plan (2021-2025) for National Economic and Social Development and the Long-Range Objectives Through the Year 2035 adopted at the fifth plenary session of the 19th CPC Central Committee were officially issued on Nov. 3. 

They stress that China will uphold the central role of innovation in its modernization drive, placing self-reliance and self-strengthening of science and technology at the top of all planning tasks and making special arrangements, for the first time in the CPC's history of five-year plans.

The CPC Central Committee originally came up with its innovation-driven development strategy at the 18th CPC National Congress, before proposing innovation as the primary driving force for development at the 19th CPC National Congress. It has been continuously carrying forward and evolving its strategies, guidelines, plans and arrangements for scientific and technological innovation. The arrangements this time, with clear strategies and pragmatic approaches, will chart a course for the evolution of sci-tech in China.

# Two key mathematical conjectures solved by Chinese professors

Chen Xiuxiong and Wang Bing, professors from the University of Science and Technology of China, made significant breakthroughs in differential geometry by solving the Hamilton-Tian and partial C0 conjectures — two problems that have confounded mathematicians for over two decades. Their paper was published November in the Journal of Differential Geometry, a peer-reviewed scientific journal of mathematics published by International Press on behalf of Lehigh University in the United States.

Differential geometry, a mathematical discipline that predominantly applies techniques of calculus to study problems in geometry, plays an important role in such fields as physics, astronomy and engineering.

It took the professors five years to study the conjectures and write the article, which is over 120 pages long. Reviewing the paper took a further six years to complete.

Simon Donaldson, a winner of the Fields Medal, the mathematical equivalent of the Nobel Prize awarded every four years to the most distinguished mathematicians aged 40 or under at the International Congress of Mathematicians, hailed it "a major breakthrough in geometry."

# Chang'e-5 spacecraft brings home moon samples

The return capsule of China's Chang'e-5 lunar probe touched down on Earth on Dec. 17, 2020. On board were the country's first samples collected from an extraterrestrial body, as well as the first samples from the lunar surface in over four decades.

The Chang'e-5 mission was one of the most challenging and complicated journeys in China's aerospace history. The probe, comprising of an orbiter, lander, ascender and returner, was launched on Nov. 24 and retrieved 1,731 grams of moon samples after a 23-day space journey. During its voyage, the probe completed several difficult tasks, including the first lift-off from an extraterrestrial body, the first rendezvous and docking in lunar orbit, and the first high-speed re-entry with samples into the Earth's atmosphere.

According to Pei Zhaoyu, deputy director of the Lunar Exploration and Space Program Center of China National Space Administration, the Chang'e-5 mission not only represents a successful conclusion of China's current lunar exploration program, but also lays the foundation for future manned lunar and deep-space expeditions.

# First nuclear unit with Hualong One reactor connected to grid

China's first nuclear power unit using Hualong One technology, a domestically developed third-generation reactor design, was connected to the grid on Nov. 27, 2020. 

Upon connection, Unit 5 of the Fuqing Nuclear Power Plant of the China National Nuclear Corporation started generating electricity in Fuqing city, southeast China's Fujian province.

All the technical indicators of the unit have met the designed requirements and the unit is functioning well, laying a solid foundation for its subsequent commercial operation, said Zhao Hao, the plant's general manager.

He added that the successful connection will help improve the competitiveness of China's nuclear power industry, improve the country's energy mix and promote its low-carbon development.  

Hualong One, one of the world's most advanced nuclear power reactor designs, has a designed lifespan of 60 years. It features 177 reactor cores, which will be replaced every 18 months and meets the highest international safety standards.

At present, a total of six nuclear power units using Hualong One technology are under construction both in China and overseas. 

# China's manned submersible Fendouzhe sets record in Mariana Trench

China's new deep-sea manned submersible "Fendouzhe" (meaning "striver" in Chinese), descended 10,909 meters into the Mariana Trench on Nov. 10 and returned to south China's Hainan province on Nov. 28, setting a new national deep-sea diving record.

A joint operation of the manned submersible and its deep-sea lander was carried out at a depth of 10,000 meters on Nov. 13. The operation, the first of its kind in the world, was also livestreamed.

In order to achieve the goal of deep-sea exploration, multiple breakthroughs have been achieved in the process of developing Fendouzhe, including in such fields as anti-water pressure structure, titanium alloy manufacturing, welding techniques, buoyancy materials and lithium batteries.

The record-setting dive signals a significant step forward by China in manned deep-sea exploration technology and equipment as well as its improvement of independent innovation, which will further the country's efforts in unveiling deep-sea mysteries and protecting marine resources.

# China achieves quantum computational advantage

China announced its achievement of quantum computational advantage by establishing a quantum computer prototype named "Jiuzhang" on Dec. 4. This is the second time that a quantum computational advantage has been secured in the world, after the first claimed by Google's quantum computer Sycamore in 2019.

The Jiuzhang quantum computer, through which up to 76 photons were detected, was developed by a Chinese research team including renowned quantum physicist Pan Jianwei and the study was published online in Science magazine.

This achievement symbolized China's first milestone on the path to achieving a quantum computational advantage, also referred to as "quantum supremacy," which suggests an overwhelming quantum computational speedup.

Named "Jiuzhang" after an ancient Chinese mathematical text, the new computer outperforms Sycamore in computational speed, environmental suitability and computing power on problems with larger samples.

Jiuzhang's quantum computing system can implement large-scale Gaussian boson sampling — a classical simulation algorithm used to demonstrate quantum computational speedup — 100 trillion times faster than the world's fastest supercomputer and 10 billion times faster than the 53-qubit Sycamore.