Archive for ‘hail’

14/08/2019

Chinese scientists hail ‘incredible’ stealth breakthrough that may blind military radar systems

  • Researchers at academy of science believe electromagnetic wave model is key that will herald new era in radar detection and avoidance for military ships and aircraft
China’s J-20 stealth fighter. Photo: AFP
China’s J-20 stealth fighter. Photo: AFP
Chinese scientists have achieved a series of breakthroughs in stealth materials technology that they claim can make fighter jets and other weaponry lighter, cheaper to build and less vulnerable to radar detection.
Professor Luo Xiangang and colleagues at the Institute of Optics and Electronics, Chinese Academy of Sciences in Chengdu, Sichuan province, said they had created the world’s first mathematical model to precisely describe the behaviour of electromagnetic waves when they strike a piece of metal engraved with microscopic patterns, according to a statement posted on the academy’s website on Monday.
With their new model and breakthroughs in materials fabrication, they developed a membrane, known as a meta surface, which can absorb radar waves in the widest spectrum yet reported.
At present, stealth aircraft mainly rely on special geometry – their body shape – to deflect radar signals, but those designs can affect aerodynamic performance. They also use radar absorbing paint, which has a high density but only works against a limited frequency spectrum.

In one test, the new technology cut the strength of a reflected radar signal – measured in decibels – by between 10 and nearly 30dB in a frequency range from 0.3 to 40 gigahertz.

A stealth technologist from Fudan University in Shanghai, who was not involved in the work, said a fighter jet or warship using the new technology could feasibly fool all military radar systems in operation today.

“This detection range is incredible,” the researcher said. “I have never heard of anyone even coming close to this performance. At present, absorbing technology with an effective range of between 4 and 18 GHz is considered very, very good.”

China’s new radar system could spot stealth aircraft from at long range

The lower the signal frequency, the longer a radar’s detection range. But detailed information about a moving target can only be obtained with higher frequency radio waves. Militaries typically use a combination of radars working at different frequencies to establish lines of defence.

The Medium Extended Air Defence System, Nato’s early warning radar, operates at a frequency range of 0.3 to 1 GHz. The American Terminal High Altitude Area Defence system, the missile defence radar that caught Beijing’s attention when it was deployed in South Korea in 2017, operates at frequencies around 10 GHz.

Some airports use extremely short-range, high-frequency radars running at 20 GHz or above to monitor vehicle and plane movements on the ground, but even they might not be able to see a jet with the new stealth technology until it is overhead.

“Materials with meta surface technology are already found on military hardware in China, although what they are and where they are used remains largely classified,” the Fudan researcher said.

Professor Luo Xiangang. Photo: Baidu
Professor Luo Xiangang. Photo: Baidu

Luo and his colleagues could not be reached for comment. But according to the academy’s statement and a paper the team published in the journal Advanced Science earlier this year, the stealth breakthroughs were based upon a discovery they made several years ago.

They found that the propagation pattern of radio waves – how they travelled – in extremely narrow metallic spaces was similar to a catenary curve, a shape similar to that assumed by chains suspended by two fixed points under their own weight.

China tests stealth ‘invisibility cloaks’ on regular fighter jets
Inspired by catenary electromagnetics, the team developed a mathematical model and designed meta surfaces suitable for nearly all kinds of wave manipulation.
These included energy-absorbing materials for stealth vehicles and antennas that can be used on satellites or military aircraft.
Zhu Shining, a professor of physics specialising in meta materials at Nanjing University, said the catenary model was a “novel idea”.
“The Institute of Optics and Electronics in Chengdu has conducted long-term research in this area which paved a solid foundation for their discoveries. They have done a good job,” Zhu said.
“Scientists are exploring new features of metal materials, some of them are already in real-life applications.”
Source: SCMP
19/12/2018

World experts hail China’s miracle-like achievements over 40 years

BEIJING, Dec. 18 (Xinhua) — As China celebrated the 40th anniversary of its reform and opening-up policy on Tuesday, the achievements it has made over the last four decades were hailed as a miracle.

Experts said that China’s reform and opening-up not only is a milestone in the country’s history but also holds global significance.

RIGHT PATH

Addressing a grand gathering Tuesday to celebrate the 40th anniversary, Chinese President Xi Jinping said that the past 40 years eloquently prove the correctness of the path, theory, system and culture of socialism with Chinese characteristics.

Robert Lawrence Kuhn, a leading American expert on China who was honored with China Reform Friendship Medal on Tuesday, said China’s direction is clear, that is, socialism with Chinese characteristics, the leadership of the Communist Party of China (CPC) in all areas, putting people and their well-being and happiness first, and the need to further implement and deepen reforms.

Russian Communist Party leader Gennady Zyuganov said the reform and opening-up policy enacted by the CPC at the third plenary session of the 11th CPC Central Committee in 1978 planned China’s development and raised China to heights unimaginable at that time.

“All the achievements that China has made is inseparable from the country’s adherence to the leadership of the CPC and taking the socialist path,” he told Xinhua in a recent interview.

Manoranjan Mohanty, former chairperson of the Institute of Chinese Studies in Delhi, said the reform and opening-up was a great revolution.

At one time it was called a “New Long March,” which has two things in common with the Long March of the Red Army – one is the determination to unite maximum popular forces and the other is to innovate a strategy of revolution, he said.

QUANTUM LEAP

Describing the reform and opening-up as “a great revolution in the history of the Chinese people and the Chinese nation,” Xi said a quantum leap has been made in the cause of socialism with Chinese characteristics.

Stephen Perry, chairman of Britain’s business networking organization 48 Group Club, said China has undergone incredible transformation since its reform and opening-up in 1978 and the country is sure to achieve its long-term target.

Perry, also recipient of the China Reform Friendship Medal, said that he had seen China turning from a backward country where most of the population lived in countryside into a country where nearly 60 percent of the population now dwell in towns and cities.

During the period, China’s grain output has doubled to over 600 million tons and modern technology is being developed in various industries, Perry noted.

William Jones, Washington bureau chief of the U.S. publication Executive Intelligence Review, told Xinhua in an interview that the 40th anniversary of the reform and opening-up is extremely important and is a pivotal moment.

China has moved from a relatively impoverished country to one of the most important economic powers in the world today, Jones said.

What is done has shown that the policy that was laid out in terms of the reform and opening-up has been a resounding success, he added.

China’s reform and opening-up over the past 40 years has proven to be the “golden key” to reviving its society, said Jin Jianmin, a senior fellow at the Fujitsu Research Institute in Tokyo, believing that the ongoing process will never stop.

Shadrack Gutto, a political analyst at the University of South Africa, recalled that when talking about China 40 years ago, people would think of the “kingdom of bicycle.”

But now automobiles made by China have been exported to the world market, said Gutto, adding that both in material and spiritual terms, Chinese people’s standard of living has been significantly improved.

PROPELLING GLOBAL PROSPERITY

The 40 years of reform and opening-up has benefited both China and the world, said Jin, emphasizing that the great demand created by China’s rapid economic growth has offered opportunities to the international community.

Farooq Sobhan, president of Bangladesh Enterprise Institute, said the China International Development Cooperation Agency, along with the Asian Infrastructure Investment Bank and the New Silk Road Fund, represents the country’s “firm commitment to promote and support economic growth, both globally and regionally.”

These institutions will “benefit Bangladesh and other developing countries to meet their growing development and infrastructure requirements,” said Sobhan.

Appreciating the China-proposed concept of a community with a shared future for mankind, Mohanty believed that “people all over the world wish the people of China even greater successes in pursuing the path of equitable and sustainable development.”

(Xinhua reporters Hu Xiaoguang, Zhang Jianhua, Zhao Xu, Wang Huihui, Jin Jing, Gui Tao, Zhu Dongyang, Hu Yousong, Liu Chen, Jiang Qiaomei, Yang Ting, Jing Jing, Liu Chuntao, Yang Shilong contributed to the story)

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