China Science & Technology Forum

[JSCh]

Wang Zeshan, Hou Yunde win China's top science award
CGTN
2018-01-08 10:16 GMT+8
Updated 2018-01-08 12:40 GMT+8

Chinese scientists Wang Zeshan and Hou Yunde won China's top science award, the State Preeminent Science and Technology Award, for their outstanding contributions to scientific and technological innovation.

China's State Science and Technology Awards ceremony was held at the Great Hall of the People in Beijing on Monday.

Wang Zeshan /Chinanews Photo

Wang is a professor of Nanjing University of Science and Technology and an academic at the Chinese Academy of Engineering, while Hou is a virologist and academic at the Chinese Academy of Engineering.

President Xi Jinping presented them with award certificates and offered congratulations at the annual ceremony which is held to honor distinguished scientists and research achievements.

Hou Yunde /Chinanews Photo‍

Other leaders, including Li Keqiang, Liu Yunshan, Zhang Gaoli, Wang Huning also attended the ceremony.

Wang Zeshan: King of gunpowder

Dedicated to the research on gunpowder for over 60 years, Wang Zeshan was awarded for his original achievements made in this field, taking the lead of the international level and rejuvenating gunpowder, one of China’s four great inventions.

Wang, born on Oct. 10, 1935 in Jilin city, northeast China’s Jilin Province, has spent his whole lifetimes working with explosives, specializing in energetic materials. Now in his eighties, Wang still spends half the year working.

Wang Zeshan at work /Xinhua Photo

Wang was the first to develop technology for reutilizing obsolete explosives, and energetic materials with low temperature sensitivity. He successfully designed propelling charge and modular change systems for the extended firing range, improving the firing range of China’s artillery by 20 percent and optimizing the ballistic performance.

This is not the first time Wang has received a national-level award. He was the first-prize winner of National Scientific and Technological Progress Awards in 1993, and National Technology Invention Awards in both 1996 and 2016.

Hou Yunde: Father of China’s interferon

Hou Yunde is a researcher at the National Institute of Viral Disease Control and Prevention, and director of the National Engineering Research Center for Viro Bio Technology. He was born on July 13, 1929, in Wujin, now a district in the city of Changzhou, Jiangsu Province.

Hou was awarded for his outstanding achievements in molecular virology, genome project interferon, and control and prevention of major infectious diseases.

Hou Yunde (L) with his team /Xinhua Photo

Hou is known as the “father of China’s interferon”. He laid the groundwork for the research of molecular virology in China, and successfully developed a genome project interferon and other cytokines products including interferon α-1b.

During the H1N1 flu’s outbreak in 2009, Hou served as a director of the Expert Committee of the Defense and Control Mechanism. His team’s successful intervention of the flu was internationally recognized.

In 1984, Hou was the first Chinese scientist to win the “Young and Middle-aged Scientists with Outstanding Contributions” title. Hou received the Ho Leung Ho Lee Prize in 1994, and Medical Science Prize of China the year after. During the following two decades he has won one first prize and seven second prizes of National Science and Technology Progress, 10 first prizes of Scientific and Technological Achievements of Ministry of Health.

 

[JSCh]

Researchers design dendrite-free lithium battery
January 8, 2018 by Lisa Zyga, Phys.org feature

​

A thin asymmetric solid electrolyte meets both the requirements of the lithium metal (blocking dendrite formation) and cathode (enabling low interface resistance). Credit: H. Duan et al. ©2017 American Chemical Society

By designing a solid electrolyte that is rigid on one side and soft on the other, researchers have fabricated a lithium-metal battery that completely suppresses dendrite formation—a major safety hazard that can cause fires and shorten battery lifetime. This design also overcomes a tradeoff that is typically present in these batteries, by simultaneously eliminating dendrite growth and reducing the resistance at the electrode/electrolyte interface. Typical methods cannot achieve both of these goals at the same time.

The researchers, from Profs. Yu-Guo Guo and Li-Jun Wan's groups of the Chinese Academy of Sciences and the University of Chinese Academy of Sciences, have published a paper on the new electrolyte in a recent issue of the Journal of the American Chemical Society.

"We have proposed an asymmetric solid electrolyte, which can concurrently meet the requirements of a dendrite-free lithium anode and a low interface resistance in solid batteries," Guo told Phys.org.

As the researchers explain, the tradeoff in lithium batteries occurs because the lithium anode and the cathode have requirements that are inherently contradictory. While the anode requires a rigid electrolyte to block dendrite growth, it is difficult for a rigid electrolyte to maintain sufficient contact with the solid cathode, which creates a highly resistive cathode/electrolyte interface.

To address this problem, the researchers designed an asymmetrical solid electrolyte, in which each side has a different type of surface. The side facing the anode is a rigid ceramic material that presses against the lithium anode to discourage dendrite growth. On the other hand, the side facing the cathode is made of a soft polymer, which allows for a strong interfacial connection with the cathode. The entire electrolyte is also very thin, at just under 36 micrometers.

In tests, the researchers compared batteries with the new electrolyte to those with a conventional electrolyte. After 1750 hours of cycling, they found that the batteries with the conventional electrolyte exhibited rough morphologies indicative of dendrite formation, while those with the new electrolyte showed no morphological changes even after 3200 hours of cycling, indicating that dendrite growth was effectively eliminated.

Going forward, the researchers expect that the dendrite-free lithium batteries will lead to energy-storage systems that combine the high energy and power densities of lithium batteries with improved safety and longer lifetimes due to eliminating dendrite growth.

"We plan to design pouch cells with this asymmetric solid electrolyte for attaining a high energy density in solid batteries," Guo said.

More information: Hui Duan, Ya-Xia Yin, Yang Shi, Peng-Fei Wang , Xu-Dong Zhang, Chun-Peng Yang, Ji-Lei Shi , Rui Wen, Yu-Guo Guo , and Li-Jun Wan. "Dendrite-Free Li-Metal Battery Enabled by a Thin Asymmetric Solid Electrolyte with Engineered Layers." Journal of the American Chemical Society (2017). DOI: 10.1021/jacs.7b10864


https://phys.org/news/2018-01-dendrite-free-lithium-battery.html

 

[JSCh]

Web Date: January 9, 2018
Rewritable paper goes technicolor
Metal-ligand complexes display a range of long-lasting colors that can be erased on demand, allowing paper to be reused

By Mark Peplow

Aqueous metal-ion inks were used to draw a sunflower on rewritable paper.
Credit: Nat. Commun.

The paper industry has a significant environmental impact, from cutting down trees for raw material to consuming large amounts of energy and water to process that material. To curb that impact, chemists have been working on rewritable paper technologies that would allow people to print on a sheet of paper with special inks and then erase them to reuse the paper.

A team now reports a form of rewritable paper that can display multicolored images and text for months, before being erased and reused time after time (Nat. Commun. 2018 DOI: 10.1038/s41467-017-02452-w).

Previous technologies have involved impregnating paper with colorless dyes that are activated by water sprayed from inkjet printers; others use dyes that show up when exposed to ultraviolet light. But these systems have struggled to create multicolored images, and the printed text rarely lasts for more than a few days.

A team at Nanjing University of Posts & Telecommunications overcame these hurdles, using water-based inks and inexpensive materials to form colored metal-ligand complexes that remain stable for at least 6 months.

The ligands are terpyridine molecules, containing three nitrogen atoms that coordinate to metal ions such as iron, zinc, and cobalt. The terpyridines also carry fluorene or triphenylamine groups that tune their optical properties.

In one demonstration, the researchers coated paper with a thin film of a poly(ethylene glycol) copolymer mixed with a terpyridine molecule. Adding aqueous solutions of different metal ions to the paper—either by freehand drawing or inkjet printing—created long-lasting colored complexes that included brown, blue, yellow and green hues. “It is exciting to see that by simply varying the metal ions, a number of distinct colors can be obtained, and the color intensity remains stable for months,” says Yadong Yin at the University of California, Riverside, who also works on rewritable paper and was not involved in this research.

Using zinc-based inks and a different terpyridine, the team printed a barcode pattern that was only visible under UV light, and which lasted for more than one year. The resolution of these patterns was comparable to that of conventional inkjet printing, and the team suggests the method could be useful for security tags.

The rewritable paper can be erased and reused five times with no significant loss in color intensity. However, the erasure process involves washing with a solution of fluoride ions to disrupt the metal-ligand complexes, a significant drawback for commercial applications. Qiang Zhao, part of the research team, says that they are already working on more practical ways to erase the paper.

In an alternative approach that avoided the fluoride wash, the team coated paper with a colorless zinc-ligand complex that luminesced orange under UV light. Then they printed patterns with an ink of pure water, which disrupted the zinc-ligand coordination bonds and changed the luminescence to cyan. Even after the paper had dried, this UV-visible image lasted for more than 6 months, and could be erased by simply heating at 65°C for 30 minutes.

The Chinese characters for ‘Nanjing University of Posts and Telecommunications’ glow cyan under UV light.
Credit: Nat. Commun.

Zhao adds that the materials they used should not prevent the paper from being recycled once its write-erase cycles are completed, and that experiments with cell cultures showed that the materials all had low toxicity.

The researchers estimate that printing a page of text on their rewritable paper could cost less than one-fifth of a conventional inkjet print on fresh paper. “We are optimistic about the commercialization of rewritable paper,” says Zhao.

Chemical & Engineering News
ISSN 0009-2347
Copyright © 2018 American Chemical Society



Rewritable paper goes technicolor | Chemical & Engineering News​

 

[JSCh]

First doubly holey MOF holds catalysis promise
By Katrina Krämer | 11 January 2018

Macroporous particles made out of microporous material could catalyse reactions between bulky molecules

Source: © K Shen et al, Science, 2018, 359, 206 (DOI: 10.1126/science.aao3403)

Tiny porous particles made out of a metal–organic framework that contains even smaller holes are the first macro–microporous material ever made. When tested in an organic reaction, the doubly holey crystals outperformed all state-of-the-art catalysts.

Metal–organic frameworks (MOFs) are highly porous. If it were possible to unfold 1g of MOF-5, one of the first MOFs ever made, its internal surface area would cover 2500m2. MOFs huge number of cavities and massive surface area makes them promising for gas storage, as well as catalytic applications.

Source: © sciencemag.org

The use of an organised template of polystyrene balls allowed scientists to create a metal–organic framework with a hierarchical network of pores

Researchers have now created a MOF that, in addition to containing its usual microscopic holes, is arranged into a regular macroscopic pore network. The team let ZIF-8 – a zinc imidazole MOF – assemble within the pores of a template of polystyrene spheres arranged into ordered particles. Once the polystyrene is removed, what remains is a negative replica of the template’s holes.

A state-of-the-art heterogeneous catalyst can catalyse the Knoevenagel condensation – a reaction between an aldehyde and a nitroalkane – to completion in 10 hours. The macro–microporous MOF can perform the same reaction within just two. The same MOF in its usual microporous-only form takes four times as long. Unlike a regular MOF, the doubly porous MOF’s reactive sites are more accessible to reagents, which can enter into the material through the macroscopic holes.

The researchers think that the material is particularly promising for promoting reactions between bulky molecules that are notoriously difficult to react.

References
K Shen et al, Science, 2018, 359, 206 (DOI: 10.1126/science.aao3403)​

First doubly holey MOF holds catalysis promise | Research | Chemistry World

 

[JSCh]

China announces top 10 news stories for defense-related science and technology in 2017
By Guo Meiping, Gao Yun
2018-01-12 21:43 GMT+8

The State Administration of Science, Technology and Industry for National Defense on Thursday announced the top 10 news stories of 2017 in defense-related science and technology, which most embody China’s achievements and breakthroughs in national defense, industry and technology last year.

1. Breakthroughs in key space project

Tianzhou-1 successfully refueled the Tiangong-2 space lab in orbit on April 27, 2017. /Xinhua Photo

China's first cargo spacecraft, the Tianzhou-1, blasted off on April 20, 2017, in south China’s Hainan Province. Carried by a Long March-7 Y2 carrier rocket, the Tianzhou-1 successfully refueled the Tiangong-2 space lab in orbit on April 27, 2017.

China's BeiDou Satellite Navigation System (BDS) covers the globe thanks to the two BeiDou-3 satellites launched into space last November. The self-developed system has been providing navigation services in the Asia-Pacific region since 2012.

(Click to read more about China’s achievements in aerospace in 2017)

2. Launches of China’s first self-developed aircraft carrier and new generation destroyer

China launched its first domestically constructed aircraft carrier on April 26, 2017. /CGTN Photo

On April 26, 2017, China launched its first domestically constructed aircraft carrier, the Type 001A, at the Dalian shipyard in northeast China's Liaoning Province. The country started building this carrier in November 2013, and dock construction started in March 2015.

(Click here to know more about the first self-developed aircraft carrier)

The new-generation missile destroyer launched on June 28, 2017 from the Jiangnan Shipyard (Group) Co., LTD. in Shanghai /VCG Photo

Two months later on June 28, the Chinese navy launched a new-generation missile destroyer from the Jiangnan Shipyard (Group) Co., Ltd. in Shanghai. The 10,000-ton domestically designed and manufactured vessel is the first in a new generation of destroyers.

(Click here to get more information about the destroyer)

3. Development in space science, space technology and space application

A diagram of the “Huiyan” satellite /China Daily Photo

China launched its first space telescope, the Hard X-ray Modulation Telescope (HXMT), on June 15, 2017. Named “Huiyan”, HXMT is tasked with surveying the Milky Way to observe black holes, pulsars and gamma-ray bursts.

What’s worth noting is that only four telescopes among dozens around the world were capable of detecting the gravitational waves at high frequency and shooting the best image resolution; HXMT was one of them.

(Click here to learn more about “Huiyan”)

4. Military parade showcased China’s advanced national defense and weaponry

President Xi Jinping inspects the armed forces to mark the 90th founding anniversary of the People's Liberation Army (PLA) at Zhurihe military training base in Inner Mongolia, July 30, 2017. /Xinhua Photo

China held a grand military parade at Zhurihe training base in northern China's Inner Mongolia Autonomous Region on July 30, 2017, in celebration of the 90th birthday of the Chinese People's Liberation Army (PLA).

Tanks, vehicle-mounted nuclear-capable missiles and other equipment rolled by, as military aircraft flew above, including H-6K bombers, the J-15 carrier-based fighters and new generation J-20 stealth fighters.

12,000 service personnel, more than 129 aircraft and 571 pieces of ground equipment appeared in 36 formations at the parade.

(Click here to read more about military parade)

5. J-20 fighter jet put into service, AG600 completed maiden flight

The J-20 is China's fourth-generation medium and long-range fighter jet. /Xinhua Photo

China's latest J-20 stealth fighter has been officially commissioned into military service, said Wu Qian, spokesperson for the Ministry of National Defense on September 28, 2017. The introduction marks dramatic progress in China's efforts to develop advanced aircraft, and strengthen its abilities to safeguard national security.

The J-20 is China's fourth-generation medium and long-range fighter jet. It made its maiden flight in 2011 and was first shown to the public at the 11th Airshow China in Zhuhai, Guangdong Province, in November last year. In July 2017, the aircraft made its parade debut as the PLA staged a show of force to mark its 90th founding anniversary.

(Click here to know more about J-20)

The AG600 is the third member of China's "large aircraft family" after the large freighter Y-20 and large passenger aircraft C919. /VCG Photo

C‍‍hina's first home-grown amphibious aircraft, the AG600, completed its maiden flight in Zhuhai, south China's Guangdong Province, on December 24, 2017. It is a major piece of aviation equipment in China’s expanding emergency rescue system and a milestone in the country's amphibious aircraft development.

Codenamed "Kunlong,” the plane was designed to be put into rescue missions both on land and water.

(Click here to get more information about AG600)

6. Shenlong-2 to lead the world's development of high-current multi-pulse accelerator

Shenlong-2 accelerator /CCTV Photo

China’s domestically-developed multi-pulse high-power accelerator “Shenlong-2,” also the world’s first of its kind, passed the state-level on-site inspection on Nov. 23, a milestone in the development of linear induction accelerator and China’s flash radiography technology.

The researchers overcame critical problems during the development process, and made innovations in the design and technologies. The inspection panel assessed that the overall technology was at an advanced level globally, and part of the key indicators took the world's lead.

7. District heating with nuclear energy to save resources and environment

The monitor showing real-time heating data by Yanlong /CCTV Photo

China unveiled its self-developed pool-type low-temperature heating reactor “Yanlong” on Nov. 28, which can continuously supply heat for 168 hours.

Developed by China National Nuclear Corporation (CNNC), the low-temperature heating reactor of 400 megawatts can supply heating covering 20 million square meters, meeting the needs of 200,000 three-bedroom families.

By utilizing nuclear energy for district heating, it can efficiently improve China’s energy structure, alleviate the increasing pressure of energy supply and reduce emissions.

(Click here to get more information about Yanlong)

8. Measures to deepen civil-military integration in defense technology industry

China has launched several measures to boost civil-military integration. /CCTV Photo

China has launched several measures to boost civil-military integration, as said in a guideline issued by the State Council on Dec. 4.

Expanding the access to military-related industry, enhancing the sharing of military and civilian resources and collaborative innovation, interchanging military and civilian technologies are means to achieve substantial breakthroughs in the civil-military integration.

(Click here to get more information about civil-military integration)

9. Launch of world’s fastest quantum random number generator

The high-speed quantum random number generator developed by China Electronics Technology Group Co. /CCTV Photo

China Electronics Technology Group Co. (CETC) unveiled a high-speed quantum random number generator (QRNG) at the 2017 World Internet Conference on Dec. 4.

With a real-time generation rate of over 5.4G per second and an ultimate rate of over 117G per second, the QRNG peeled off the record set by its predecessors, ranking the world’s fastest.

As the core device to realize quantum secure communication, the one developed by CETC is at the world’s advanced level and can be widely used in the quantum communication industry and information security industry.

10. Delivery of world’s first smart bulk carrier

The world's first smart bulk carrier "Da Zhi" /CCTV Photo

Developed by China State Shipbuilding Corporation, the world's first smart bulk carrier "Da Zhi" was delivered in Shanghai on Dec. 5, kicking off an era of more secure, economical and environmental-friendly shipping.

It is equipped with up-to-date information technologies, including the world's first self-learning information platform, large-capacity calculations and a China-developed intelligent remote control system.

The smart vessel is also the world's first to get recognition from both Lloyd's Register and the China Classification Society.

(Click here to learn more about Da Zhi)

 

[Adam WANG SHANGHAI MEGA]

China launches land exploration satellite
Source: Xinhua| 2018-01-13 17:06:13|Editor: Mengjie

China launches a land resources exploration satellite into a preset orbit from the Jiuquan Satellite Launch Center in the Gobi desert, China, on Jan. 13, 2018. (Xinhua/Wang Jiangbo)

JIUQUAN, Jan. 13 (Xinhua) -- China launched a land resources exploration satellite into a preset orbit from the Jiuquan Satellite Launch Center in the Gobi desert at 3:10 p.m. Saturday Beijing Time.

A Long March-2D rocket carried the satellite into space.

The launch was the 263th mission of the Long March rocket series.

 

[yusheng]

Zhaoxin's home-grown x86 CPU is completely designed from the ground up within China. The Central Processing Unit not only offers reliability and great performance, but hardware security features for the highest level of data protection. The x86 CPU supports a wide variety of Windows Operating System

 

[JSCh]

Public Release: 17-Jan-2018
The world's first all-Si laser
Science China Press

(a) A schematic image of DFB Si laser; Inset: photograph of a fabricated DFB device. (b) Emission spectra of the Si laser as a function of pump power; Background: a cross-sectional SEM image of the DFB structure.
©Science China Press

Integrated Si photonics incorporates the essence of the two pillar industries of "microelectronics" and "optoelectronics", which is expected to bring new technological revolution in a variety of fields such as communication, sensing, lighting, dispalay, imaging, detection, etc. Si lasers are the key to achieve integrated Si photonics. However, the optical gains of Si are lower than those of III-V compound semiconductors by one order of magnitude or two, due to its indirect bandgap feature. Although the fabrication of matured III-V compound lasers on Si substrates has been proposed to circumvent this problem, the development of all-Si laser is still in high demand for integrated Si photonics, due to its better compatibility with modern Si techniques.

Recently, a joint research team led by Prof. X. Wu, Prof. M. Lu and associate Prof. S.-Y. Zhang from Fudan University developed the world's first all-Si laser using Si nanocrystals with high optical gains. First, they enhanced the Si emission intensity greatly by developing a film growth technique for high-density silicon nanocrystals (Physica E, 89, 57-60(2017)). Then, they developed a high-pressure low-temperature passivation approach, which contributed to a full saturation of dangling bonds, leading to increased optical gains that were comparable to those achieved by gallium arsenide (GaAs) and indium phosphide (InP). On this basis, they designed and fabricated distributed feedback (DFB) resonance cavities and successfully achieved optically pumped all-Si DFB lasers. The optically pumped all-Si laser also paves the way towards the realization of electrically pumped all-Si laser.

It was found that the optical gain of Si nanocrystals was constantly enhanced as the passivation proceeded and eventually reached the value comparable to those of GaAs and InP. Lasing characteristics - the threshold effect, the polarization dependence, the significant spectral narrowing and small spread of divergence angle of stimulated emission - were fulfilled, suggesting the realization of an optically pumped all-Si laser. The lasers also showed reliable repeatability. The lasing peaks of the four additional samples made under the similar fabrication conditions were within the spectral range of 760 nm to 770 nm. The variation in the lasing peak was due to the slight difference in effective refractive indices. The full-width-at-half-maximum (FWHM) of the emission peak was narrowed from ~120 nm to 7 nm when the laser was pumped above threshold. This program is supported by the National Natural Science Foundation of China (51472051, 61275178, 61378080, 61705042) and Shanghai Sailing Program (16YF1400700).

###​

Dong-Chen Wang#, Chi Zhang#, Pan Zeng, Wen-Jie Zhou, Lei Ma, Hao-Tian Wang, Zhi-Quan Zhou, Fei Hu, Shu-Yu Zhang*, Ming Lu*, and Xiang Wu*. An all-silicon laser based on silicon nanocrystals with high optical gains. Science Bulletin, https://www.sciencedirect.com/science/article/pii/S2095927318300069


The world's first all-Si laser | EurekAlert! Science News

 

[JSCh]

Scientists used diamond tips to apply enormous pressure to a superconducting alloy. Credit: Max Alexander/SPL

06 December 2017
Super-squeezing can’t crush this superconductor’s powers
Material shrugs off pressures similar to those at Earth’s core.

An exotic alloy conducts electricity when subjected to extreme pressures that would be expected to crush the material’s structure and destroy its electrical properties.

The alloy is a superconductor, a material that offers no resistance to the passage of an electrical current. Such materials are valuable for fabricating specialized magnets and other technology. But extreme pressures distort their atomic arrangements, disrupting their ability to carry current.

Liling Sun at the Chinese Academy of Sciences in Beijing, Robert Cava at Princeton University in New Jersey and their colleagues subjected samples of the alloy to pressures of up to 190 gigapascals — nearly 2 million times the atmospheric pressure at sea level — about the level in Earth’s outer core. The alloy’s superconductivity persisted. That contradicts scientists’ understanding of how such materials should behave, providing a challenge to superconducting theory, the authors say.

Proc. Natl Acad. Sci. USA (2017)



Super-squeezing can’t crush this superconductor’s powers : Research Highlights | Nature

A material that superconducts continuously up to extreme pressures
January 17, 2018 by Laura Mgrdichian, Phys.org feature

A rendering of the HEA sample being squeezed between the culets of two diamonds. Credit: Liling Sun

Researchers have discovered a metal alloy that can conduct electricity with zero resistance, or superconduct, from ambient pressure up to pressures similar to those that exist near the center of the Earth. The material, which is likely the first to show this kind of robust superconductivity, is described in a paper in the December 12, 2017, edition of the Proceedings of the National Academy of Sciences.

The material is a member of a new family of metal alloys known as high-entropy alloys (HEAs), which are composed of random atomic-scale mixtures of elements from the block of "transition metals" on the periodic table. HEAs are interesting in multiple ways, including structurally. They have simple crystal structures, but the metals are arranged randomly on the lattice points, giving each alloy the properties of a both a glass and a crystalline material.

The HEA studied in this work is unique in that it can superconduct continuously from low to high pressures – even when subjected to pressures akin to those that exist at the outer area of our planet's core. This discovery was made by a group of scientists from the Institute of Physics at the Chinese Academy of Sciences and the Chemistry Department at Princeton University. The HEA they studied is composed of the metals tantalum (Ta), niobium (Nb), hafnium (Hf), zirconium (Zr), and titanium (Ti).

"We have observed that this HEA remains in a state of zero electrical resistance all the way from one-bar of pressure to the pressure of the Earth's outer core, without structural changes," said one of the study's senior researchers, Professor Liling Sun of the Institute of Physics in Beijing, to Phys.org.

Robert Cava, the Russell Wellman Moore Professor of Chemistry at Princeton, another senior author, added, "This is a remarkable thing – we know of no other similar material – and it makes this HEA a promising candidate for new applications of superconductors under extreme conditions."

Pressure is one of the external variables that can uncover unexpected characteristics in a material. In superconductors, for example, the application of pressure has changed critical temperatures (the temp below which a material will superconduct) and induced superconductivity in materials that otherwise wouldn't exhibit the phenomenon.

Here, the group applied pressure to the HEA using a diamond anvil cell, a device that uses the polished faces of two diamonds – one of the hardest materials on Earth – to squeeze a sample placed between them. To generate sufficiently high pressure to perform the measurements on the HEA, the size of each diamond's culet – the "point" at the bottom of the gem – was 40 microns (millionths of a meter), which is about half the diameter of a human hair.

To track the possible structural changes while the sample was in the diamond anvil cell, the group used synchrotron-based x-ray diffraction (XRD) at the Shanghai Synchrotron Radiation Facility. XRD allows researchers to gain structural information on a crystalline sample based on the pattern the x-rays make after they diffract away from the atoms in the sample. They combined these techniques with complementary measurements of resistivity and magnetoresistance to characterize the superconductivity.

The results show that the HEA retains its basic crystal structure, despite the sample's volume being compressed considerably (by one measurement, when the pressure was about 96 GPa, the volume had been reduced by about 28 percent).

Sun, Cava, and their colleagues attribute the material's unique behavior and stability to its strong crystal structure, combined with the seemingly robust nature of its electronic structure when subjected to a very large amount of lattice compression.

More information: J. Guo et al, "Robust zero resistance in a superconducting high-entropy alloy at pressures up to 190 GPa." Proc Natl Acad Sci, 114 (2018), DOI: 10.1073/pnas.1716981114

https://phys.org/news/2018-01-material-superconducts-extreme-pressures.html

 

[JSCh]

EDITORIAL 17 January 2018
China needs to listen to its researchers to become a scientific superpower
The country’s research could soon dominate the world stage, but pitfalls lie in wait.

China’s Long March 5 rocket. The country’s science is heading up, but significant concerns remain.Credit: Xinhua News Agency/REX/Shutterstock

In the past 12 months or so, China has opened its first facility for research into the world’s most dangerous pathogens, unveiled another world-leading telescope and turned on its first world-class neutron source. Researchers in the country have also established a neuroimaging factory to automate the highly detailed imaging of human brains.

Money has poured in, too. Chinese artificial-intelligence (AI) companies, in a crowded field, impressed international investors. Companies specializing in computer-vision technology pulled in more than US$1 billion in investment last year. Legend Biotech in Nanjing reported positive results from a clinical trial of a CAR-T therapy — showing its clout in a highly competitive field in which researchers engineer a patient’s own cells and reintroduce them to treat cancer. In response, Janssen Biotech of Horsham, Philadelphia, put $350 million into further development of the therapy.

Look at most scientific indicators — publications, patents, number of researchers — and China seems to be on course to sail into scientific dominance. And, as many observers point out, that could happen much sooner than anyone previously expected if the US government continues to hold policies as destructive to science as those pushed by the administration of President Donald Trump. The upshot of this is a lot of opportunities for researchers in China. A Career Guide this week offers details on how to embrace them.

But pitfalls lie in wait if officials and researchers in China are not careful. The country’s AI research, for example, is booming right now, with publications outpacing those produced in the United States. But researchers acknowledge that many of these papers are not of particularly high quality. They also wonder whether Chinese academia or industry will invest in the ways necessary to create fundamental breakthroughs in the field.

As we discuss in a News story this week, billions of dollars announced for a provincial AI park in China came as a surprise to many AI researchers in the capital, Beijing. This doesn’t bode well, because it suggests a top-down effort made without consulting the research or academic community. Existing pricey science parks dedicated to trendy fields such as biotechnology and software development have produced mixed results and raised the question of whether resources are being wasted on fancy infrastructure.

Meanwhile, China might ratchet up its firm grip on the Internet. If it does so, many scientists there could lose access to the virtual private networks that they use to bypass restrictions and reach crucial websites such as Google Scholar. That would cut off access to literature, results and discussion, and isolate them from the international community.

Despite China’s claim to the throne of scientific superpower, the government retains a soft spot for unproven claims of traditional Chinese medicine. (This is one area in which the United States, in its attempts to rein in naturopathy and homeopathy in the past two years, seems to be cleaning up its own scientific house.)

The lack of transparent or predictable funding decisions could also derail China’s ambitions. Although the National Natural Science Foundation of China is generally well regarded for the grants it distributes, however small, larger projects continue to be marked by disarray. Neuroscientists have been sounded out to join a multimillion-dollar national programme meant to rival (and hopefully complement) brain-science projects in the United States, Europe and Japan. But so far, all the Chinese project has produced is false starts and confusion as scientists attempt to ready their research programmes to align with a national project that is always just around the corner.

China is right to praise itself for its accomplishments in building a successful scientific community. And its stated goals of becoming an attractive place for foreign or returning scientists and a more desirable partner for international collaborations are the right ones for a country ready to take up a much needed leadership role and act as a model for other nations. But China will need to make more effort to listen to its scientists and survey the needs of researchers elsewhere to find out what problems — including those mentioned above — might hamper attainment of those goals.



China needs to listen to its researchers to become a scientific superpower | Nature

 

[JSCh]

NEWS | 18 January 2018
China declared world’s largest producer of scientific articles
Report shows increasing international competition, but suggests that United States remains a scientific powerhouse.

Jeff Tollefson

For the first time, China has overtaken the United States in terms of the total number of science publications, according to statistics compiled by the US National Science Foundation (NSF).

The agency’s report, released on 18 January, documents the United States’ increasing competition from China and other developing countries that are stepping up their investments in science and technology. Nonetheless, the report suggests that the United States remains a scientific powerhouse, pumping out high-profile research, attracting international students and translating science into valuable intellectual property.

“The US continues to be the global leader in science and technology, but the world is changing,” says Maria Zuber, a geophysicist at the Massachusetts Institute of Technology in Cambridge. As other nations increase their output, the United States’ relative share of global science activity is declining, says Zuber, who chairs the National Science Board, which oversees the NSF and produced the report. “We can’t be asleep at the wheel.”

The shifting landscape is already evident in terms of the sheer volume of publications: China published more than 426,000 studies in 2016, or 18.6% of the total documented in Elsevier’s Scopus database. That compares with nearly 409,000 by the United States. India surpassed Japan, and the rest of the developing world continued its upward trend.

But the picture was very different when researchers examined where the most highly cited publications came from. The United States ranked third, below Sweden and Switzerland; the European Union came in fourth and China fifth. The United States still produces the most doctoral graduates in science and technology, and remains the primary destination for international students seeking advanced degrees — although its share of such students fell from 25% in 2000 to 19% in 2014, the report says.

The United States spent the most on research and development (R&D) — around US$500 billion in 2015, or 26% of the global total. China came in second, at roughly $400 billion. But US spending remained flat as a share of the country’s economy, whereas China has increased its R&D spending, proportionally, in recent years.

Credit: National Science Foundation

The NSF analysis, the latest edition of the agency’s biennial Science and Engineering Indicators, comes at a time of heightened concern about the state of US science. It should raise some alarms, says Mark Muro, a senior fellow with the Brookings Institution, a think tank in Washington DC. Trends in US science spending are heading in the wrong direction, he says, and the talent pool of researchers continues to be limited by under-representation of women and minorities. Similarly, key industries such as semiconductors have been hollowed out as businesses ship production work to other countries, Muro adds.

For the first time, the NSF included a section on technology transfer and innovation in its statistical analysis. Data suggest that the United States continues to lead the world when it comes to things like patents, revenue from intellectual property and venture capital funding for innovative technologies. Although more focus is needed at the local and regional level, Muro says, the report nonetheless provides important data about the value of scientific innovation.

“A nation’s innovation capacity is one of the main drivers of productivity growth and so prosperity,” Muro says. The new data provide “a useful reminder of why we care about these indicators in the first place.”



China declared world’s largest producer of scientific articles | Nature

 

[JSCh]

American, Chinese scientists find new way to develop flu vaccines
Source: Xinhua| 2018-01-19 03:58:03|Editor: yan



WASHINGTON, Jan. 18 (Xinhua) -- A team of American and Chinese scientists have found a new approach to vaccine development that may effectively prevent the seasonal flu, a new study says.

Scientists from two countries used cutting-edge genomics to identify and eliminate the virus' defense mechanisms, enabling them to develop a vaccine "candidate" that in animals has been proven to be safe and highly effective against influenza, according to the study published in the journal Science on Thursday.

The study shows that the engineered influenza virus induced strong immune responses in animals.

Scientists are hopeful that their approach could lead to a new, more effective vaccine that can be taken as a nasal spray at home, rather than an injection by a health professional.

"Because the variations of seasonal influenza viruses can be unpredictable, current vaccines may not provide effective protection against them," said Ren Sun, a professor of molecular and medical pharmacology at University of California Los Angles and the study's senior author.

The key to the new vaccine is an understanding of the interactions between the virus and interferons, which are proteins that are critical to the body's immune response.

In the study, Sun and his Chinese colleagues defined the function of every amino acid in the influenza virus's entire genome, and deactivated the sequences that prevent interferon induction, so the interferon production would be highly stimulated in organisms infected with the virus.

"By disabling these interferon-evasion functions, the engineered virus is weakened in typical hosts," said Yushen Du of Zhejiang University School of Medicine, the study's first author. "At the same time, however, due to interferon stimulation, the engineered virus generates very strong immune responses."

Although researchers have disabled genetic sequences that block interferon before, the scientists were the first to systematically identify and eliminate multiple interferon-evasion sites at single amino acid resolution on the virus.

"Other researchers have knocked out one anti-interferon sequence, but we knocked out eight locations by changing one amino acid at a time," Du said.

Sun and his colleagues plan to test the vaccine in animals with two strains of influenza before moving to clinical trials with humans. He said the approach could also be applied to developing vaccines against a wide range of other viruses.

Yushen Du, Li Xin, Yuan Shi, Tian-Hao Zhang, Nicholas C. Wu, Lei Dai, Danyang Gong, Gurpreet Brar, Sara Shu, Jiadi Luo, William Reiley, Yen-Wen Tseng, Hongyan Bai, Ting-Ting Wu, Jieru Wang, Yuelong Shu, Ren Sun. Genome-wide identification of interferon-sensitive mutations enables influenza vaccine design. Science (2018). DOI: 10.1126/science.aan8806​

 

[yusheng]

cold lunching satellites 2018 Jun 19

 

[JSCh]

Micius Satellite Enables Intercontinental Quantum Communications
January 19, 2018

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Illustration of the three cooperating ground stations (Graz, Nanshan, and Xinglong). Listed are all paths used for key generation and the corresponding final key length. Credit: University of Science and Technology of China

Private and secure communications are fundamental human needs. In particular, with the exponential growth of Internet use and e-commerce, it is of paramount importance to establish a secure network with global protection of data. Traditional public key cryptography usually relies on the computational intractability of certain mathematical functions. In contrast, quantum key distribution (QKD) uses individual light quanta (single photons) in quantum superposition states to guarantee unconditional security between distant parties. Previously, the quantum communication distance had been limited to a few hundred kilometers, due to the optical channel losses of fibers or terrestrial free space. A promising solution to this problem exploits satellite and space-based link, which can conveniently connect two remote points on the Earth with greatly reduced channel loss because most of the photons’ propagation path is in empty space with negligible loss and decoherence.

A cross-disciplinary multi-institutional team of scientists from the Chinese Academy of Sciences, led by Professor Jian-Wei Pan, has spent more than ten years developing a sophisticated satellite, Micius, dedicated to quantum science experiments, which was launched on August 2016 and orbits at an altitude of ~500 km. Five ground stations are built in China to cooperate with the Micius satellite, located in Xinglong (near Beijing), Nanshan (near Urumqi), Delingha (37°22’44.43”N, 97°43’37.01″E), Lijiang (26°41’38.15”N, 100°1’45.55”E), and Ngari in Tibet (32°19’30.07”N, 80°1’34.18”E). Within a year after the launch, three key milestones for a global-scale quantum internet have been achieved: satellite-to-ground decoy-state QKD with kHz rate over a distance of ~1200 km (Liao et al. 2017, Nature 549, 43); satellite-based entanglement distribution to two locations on the Earth separated by ~1200 km and Bell test (Yin et al. 2017, Science 356, 1140), and ground-to-satellite quantum teleportation (Ren et al. 2017, Nature 549, 70). The effective link efficiencies in the satellite-based QKD were measured to be ~20 orders of magnitudes larger than direct transmission through optical fibers at the same length of 1200 km. The three experiments are the first steps towards a global space-based quantum internet.

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One-time-pad file transfer. Credit: University of Science and Technology of China

The satellite-based QKD has now been combined with metropolitan quantum networks, in which fibers are used to efficiently and conveniently connect numerous users inside a city over a distance scale of ~100 km. For example, the Xinglong station has now been connected to the metropolitan multi-node quantum network in Beijing via optical fibers. Very recently, the largest fiber-based quantum communication backbone has been built in China, also by Professor Pan’s team, linking Beijing to Shanghai (going through Jinan and Hefei, and 32 trustful relays) with a fiber length of 2000 km. The backbone is being tested for real-world applications by government, banks, securities and insurance companies.

The Micius satellite can be further exploited as a trustful relay to conveniently connect any two points on Earth for high-security key exchange. To further demonstrate the Micius satellite as a robust platform for quantum key distribution with different ground stations on Earth, QKD from the Micius satellite to Garz ground station near Vienna has also been performed successfully this June in collaboration with Professor Anton Zeilinger of Austrian Academy of Sciences. The satellite thus establishes a secure key between itself and, say, Xinglong, and another key between itself and, say, Graz. Then, upon request from the ground command stations, Micius acts as a trusted relay. It performs bitwise exclusive OR operations between the two keys and relays the result to one of the ground stations. That way, a secret key is created between China and Europe at locations separated by 7600 km on Earth. This work points towards an efficient solution for an ultra-long-distance global quantum network.

A picture of Micius (with a size of 5.34 kB) was transmitted from Beijing to Vienna, and a picture of Schrödinger (with a size of 4.9 kB) from Vienna to Beijing, using approximately 80 kbit secure quantum key for one-time-pad encoding.

An intercontinental videoconference was also held between the Chinese Academy of Sciences and the Austria Academy of Sciences, employing the Advanced Encryption Standard (AES)-128 protocol that refreshed the 128-bit seed keys every second. The videoconference lasted for 75 min with a total data transmission of ~2 GB, which included ?560 kbit of the quantum key exchanged between Austria and China.

Publication: Sheng-Kai Liao, et al., “Satellite-Relayed Intercontinental Quantum Network,” Physical Review Letters, 2018; doi:10.1103/PhysRevLett.120.030501

Source: Sheng-Kai Liao, University Of Science And Technology Of China


Micius Satellite Enables Intercontinental Quantum Communications

 

[JSCh]

Public Release: 19-Jan-2018
NMRCloudQ: A quantum cloud experience on a nuclear magnetic resonance quantum computer
Science China Press
https://www.eurekalert.org/multimedia/pub/160835.php

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Connection between different parts of the NMRcloudQ platform. ©Science China Press

Quantum computers are coming and attract attentions from scientists all over the world. However, as of today, no one can tell when a universal quantum computer with thousands of logical quantum bits will be built. At present, most quantum computer prototypes involve less than ten individually controllable qubits, and only exist in laboratories for the sake of either the great costs of devices or professional maintenance requirements. Moreover, scientists believe that quantum computers will never replace our daily, every-minute use of classical computers, but would rather serve as a substantial addition to the classical ones when tackling some particular problems, Due to the above two reasons, cloud-based quantum computing is anticipated to be the most useful and reachable form for public users to experience with the power of quantum.

As initial attempts, IBM Q has launched influential cloud services on a superconducting quantum processor in 2016, but no other cloud services have followed up yet in china. Recently, three research teams from Prof. G. L. Long at Tsinghua University, Ali-USTC joint program and Quantum BenYuan at USTC launched their cloud services on the same day. Different from the existing cloud services, a joint team led by G. Long at Tsinghua University, B. Zeng at University of Guelph and D. Lu at SUSTech presents a new cloud quantum computing NMRCloudQ which is based on well-established nuclear magnetic resonance. NMRCloudQ sevice provides a comprehensive software environment and aims to be freely accessible to either amateurs that look forward to keeping pace with this quantum era or professionals that are interested in carrying out real quantum computing experiments in person. In the current version, 4 -qubit NMRCloudQ provides users with 20 single-qubit gates and 9 two-qubit gates for building quantum circuit on line and density matrix of the final state after finishing experiments. Randomized Benchmarking tests show that average 99.10% single-qubit gate fidelity and 97.15% two-qubit fidelity are achieved. Improved control precisions after updating a new sample with longer coherence time and stronger coupling between different nuclei will be available later. Benefitting from the mature techniques in experimental quantum computing, NMRCloudQ may open the control layer to users in the future.

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See the article: Tao Xin, Shilin Huang, Sirui Lu, Keren Li, Zhihuang Luo, Zhangqi Yin, Jun Li, Dawei Lu, Guilu Long, and Bei Zeng. NMRCloudQ: A quantum cloud experience on a nuclear magnetic resonance quantum computer. Science Bulletin, 2018, 63(1)17-23
Doi: 10.1016/j.scib.2017.12.022
https://www.sciencedirect.com/science/article/pii/S2095927317306412



NMRCloudQ: A quantum cloud experience on a nuclear magnetic resonance quantum computer | EurekAlert! Science News