News on China's scientific and technological development.

China completed network of four enormous radio telescopes in 2006 for Chang'e-1


A radio telescope, used for monitoring China's first moon orbiter Chang'e-1, is seen at the Urumqi observatory in Urumqi (i.e. capital of northwest China's Xinjiang Uygur Autonomous Region) on Oct. 24, 2007. Observatories in Shanghai, Beijing, Kunming and Urumqi monitored the orbiter after it launched at 6:05 p.m. on Wednesday. (Xinhua/Wang Fei)



"China completes radio telescope for moon-probe project
UPDATED: 08:06, April 04, 2006

Chinese scientists on Monday completed the main part of a high-tech radio telescope which will serve China's ambitious moon-probe project scheduled for launch in 2007.

The 45-meter tall telescope weighs 400 tons and measures 40 meters in diameter for the antenna. It's located in southwest China's Yunnan Province and is the country's second-largest radio telescope. The largest is being built in Beijing.

According to Li Yan, director of Yunnan Observatory of Chinese Academy of Sciences, together with two radio telescopes already set up in Shanghai and northwest China's Xinjiang Uygur Autonomous Region, China now has four large radio telescopes which are 2,000 to 3,000 kilometers apart from each other.

The telescopes will form a comprehensive earth-based research and survey network that will be able to detect, track and retrieve data sent back from China's first moon-orbiting satellite, Li said.

Located on top of the 2000-meter-tall Mountain Phoenix in an eastern suburb of Kunming, capital city of Yunnan Province, the newest radio telescope is "superbly well positioned", the scientist said.

The construction of the telescope started in August last year and will be completely installed and tested by June.

Source: Xinhua"



"The BACC (i.e. Beijing Aerospace Control Center) said the VLBI transponder on board the satellite has started operation in the early hours on Saturday and China's four ground monitoring stations, with the application of VLBI (or "Very Long Baseline Interferometry") technology, have been monitoring Chang'e-1.

The VLBI technology helps to reduce the time needed for orbit determination, according to Ji."

China made 8 breakthroughs in space telemetry, tracking, and control


"Yuanwang 2 in Waitemata Harbour, Auckland, New Zealand on October 27, 2005. The ship was resupplying after being at sea to support the Shenzhou 6 spaceflight."



"Yuanwang 5 has a full displacement of 25,000 tonnes and is equipped with a whole range of space tracking and communications systems, including an S-band and C-band tracking and control system; and a C-band pulse radar. The ship is capable of tracking space launch vehicles, satellites, manned spacecraft, and other types of spacecraft; as well as real-time voice/image communication and data exchange with the land-based control centre.

Yuanwang 5 features a fibre optics-based shipboard network for data sharing and exchange between different sub-systems onboard. The living conditions for the crew have also been significantly improved compared to previous Yuanwang space tracking ships. According to the Chinese media report, Yuanwang 6 differs from Yuanwang 5 in that it has a large mission control hall occupying two decks. The ship is expected to be commissioned in 2008.

Mission Equipment

The ships are fitted with C- and S-band monopulse tracking radar, Cinetheodolite laser ranging and tracking system, velocimetry system, and onboard computers to track and control the spacecraft. They use a combination of inertial, satellite, and stellar for accurate navigation and positioning. Communications include HF, ULF, UHF, and SATCOM, in the form of secured telephone, radio, fax and data link. The ships are also equipped with a range of weather forecasting equipments including weather radar, sonde, weather balloon, and meteorological satellite image receiving terminal."



"China made 8 breakthroughs in space telemetry, tracking, and control
17:10, September 14, 2010

In the course of 50 years of development, China's space telemetry, tracking and control technology has evolved from scratch; formed an unique, multi-functional and air-ground space telemetry, tracking and control system; accomplished all space launch, telemetry, tracking and control tasks and has achieved eight key breakthroughs, according to the ceremony for the 30th anniversary of the founding of the Spacecraft Telemetry, Tracking and Control Committee under Chinese Society of Astronautics as well as the 25th Space Telemetry, Tracking and Control Academic Annual Meeting held in Beijing on Sept. 13th.

The first breakthrough is the success in independent research and development of large optical and radio measurement instruments.

The second is the further leap forward in systematic planning, design and construction of missile and space telemetry, tracking and control networks that have focused on the three tasks of long-range missile whole-course flight tests, submarine-to-ground missile flight tests and geostationary communications satellite launch tests. The networks cover almost all types of missiles and satellites and have become part of China's comprehensive telemetry, tracking and control facilities.

Third, the scope of China's Space Tracking, Telemetry and Command (TT&C) network has expanded from land to oceans, which is marked by the establishment of the Yuanwang Fleet consisting of six surveying vessels.

Fourth, China independently developed several crucial technologies and built the communications network for manned space flights, which is a major breakthrough in the country's aerospace research.

Fifth, based on the establishment and utilization of the Beidou Satellite Navigation System and the Space-based TT&C System, the scope of China's tracking, telemetry and control network has extended from the Earth to outer space.

Sixth, the successful completion of the Chang'e-1 mission, which is part of China's lunar exploration program, represents a major breakthrough in the country's tracking, telemetry and control capabilities in deep space.

Seventh, China helped the International Maritime Satellite Organization build a satellite monitoring station in Beijing. This was the first time that China's space tracking, telemetry and control technologies were applied in the international market and it has promoted China's cooperation with foreign countries and international organizations in satellite monitoring.

Eighth, China successfully exported a ground-control station to Nigeria, which was China's first export of an entire ground-control station. It has laid a good foundation for China's space tracking, telemetry and control technologies to occupy a prominent position on the international market.

By Zhao Chenyan, People's Daily Online"

A New Front Of Warfares

Chinese Researchers Make Cloned Human Blastocysts


"(Clockwise from left) Three-, 5-, and 6-day-old cloned blastocysts."

"At the press release, leader of the research team, Li Jian-yuan explained the newly invented cloning technology is expected to facilitate medical treatment for patients like the sufferers of Parkinson disease."



"Chinese Researchers Make Cloned Human Blastocysts
Tuesday, 3 February 2009

SCNT Using an Alternative Enucleation Method for Patient-specific Embryonic Stem Cells (ESCs)
Tuesday, 03 February 2009

China Daily report that a research team at the Shandong Stem Cell Engineering Research Center has successfully cloned five human blastulas from 135 eggs on experiment, according to a press conference jointly held by the research centre and Yantai Procreation Medicine Center on Monday. The Yantai Region is located north-central on the Shandong Peninsula, south of the Bohai Sea.

Of the five cloned human blastulas, four were from skin fibroblasts of healthy donors while the other one was from lymphocytes of patients with Parkinson disease.

At the press release, leader of the research team, Li Jian-yuan explained the newly invented cloning technology is expected to facilitate medical treatment for patients like the sufferers of Parkinson disease.

Somatic cell nuclear transfer (SCNT) was used to generate patient-specific embryonic stem cells (ESCs) from blastocysts cloned by nuclear transfer (ntESCs). In this study, a total of 135 oocytes were obtained from 12 healthy donors (30–35 years). Human oocytes, obtained within 2 h following aspiration, were enucleated and human fibroblasts or lymphocytes were used to construct the SCNT embryos.

The web edition of the science journal "Cloning and Stem Cells" reported the Chinese scientific achievement on January 27, 2009.

Reference:
Human Embryos Derived by Somatic Cell Nuclear Transfer Using an Alternative Enucleation Approach
Jianyuan Li, Xuexia Liu, Haiyan Wang, Shouxin Zhang, Fujun Liu, Xuebo Wang, Yanwei Wang. Cloning and Stem Cells. ahead of print. doi:10.1089/clo.2008.0041"

China gets success in cloning world's first rabbit



"China gets success in cloning world's first rabbit
Parul G | Jul 24 2007



After research of more than three decades in cloning and producing the first cloned animal, a goat in 2000, China has once again been successful in cloning world’s first rabbit. The Chinese scientists have produced the cloned female rabbit biologically, using the somatic cells of a rabbit fetus.

Dr. Li Shangang who conducted the experiment of rabbit cloning is a researcher at the National Center for Molecular Genetics and Animal Breeding of the Beijing Institute of Animal Sciences.

Dr. Li and his team chose the back skin cells of a 20-day old rabbit embryo. They cultured these cells into fibroblast cell lines. Then these fibroblast cells (donor cells) were fused with an enucleated rabbit’s oocyte (immature egg cell of animal ovary) through electric pulse. Thus cloned embroys were produced which were later transferred into the rabbit’s oviduct. The female clone rabbit was born after a month-long normal pregnancy on February 12 and had weighed 60 grams at birth. Now the rabbit is doing well and is at an animal center in Shanghai.

The first animal to be cloned using somatic cells was the sheep - Dolly in 1996. Since then many other animals as mice, cattle and pigs have been cloned by scientists.

In 2002, French scientists too had claimed to produce the world’s first cloned rabbit but that was done by using cells from an adult female rabbit. However, the Chinese rabbit is the world’s first clone rabbit that has used “fibroblast” cells from a fetal rabbit.

On the achievement, Wang Hongguang, director of the China Center for Biotechnology Development affiliated to the Ministry of Science and Technology said:

Chinese cloning research has reached a global advanced level. We can reproduce almost all the cloning results in top-class laboratories around the world. However, we are lacking in original creations such as the newly cloned rabbit.

Rabbits are considered significant research tools because of their shorter gestation period than other big mammals such as sheep or cows.

Malaysia has also turned to cloning and is in efforts to clone some of its threatened leatherback turtles to save them from extinction.

Source: Reuters"


"China's Liberation Daily reports today that the world's first transgenic-cloned rabbit is now three months old and living happily in Shanghai. The rabbit was cloned from the skin cells of a 20-day-old embryo, which were then implanted into the oviduct of a female rabbit."
(The photo shows the cloned rabbit (left) and her surrogate mother.
Posted by Xujun Eberlein)



"As rabbits share similar genes with humans, the genetically-modified cloned rabbit is expected to be used for research into cardiovascular and eye diseases as well as some genetic ailments, said Dr. Li Shangang with the Chinese Academy of Agricultural Sciences."

Glowing cloned pig passes on the trait


"The piglets were displayed earlier this week. When irradiated under ultraviolet radiation, the green fluorescence protein the piglets possess is visible. (China Daily via Reuters)"



"Glowing cloned pig passes on the trait
Inherited altered genes could lead to breeding organs for humans, researchers say
January 10, 2008|By Christopher Bodeen, Associated Press


A researcher holds two piglets born to a cloned pig under ultraviolet light to show their inherited green glow. Associated Press photo
Credit: Associated Press

Beijing - — A cloned pig whose genes were altered to make it glow fluorescent green has passed on the trait to its young, a development that could lead to the future breeding of pigs for human transplant organs, a Chinese university reported.

The glowing piglets' birth proves transgenic pigs are fertile and able to pass on their engineered traits to their offspring, according to Liu Zhonghua, a professor overseeing the breeding program at Northeast Agricultural University.

"Continued development of this technology can be applied to ... the production of special pigs for the production of human organs for transplant," Liu said in a news release posted Tuesday on the university's Web site.

Calls to the university seeking comment Wednesday were not answered.

The piglets' mother was one of three pigs born with the trait in December 2006 after pig embryos were injected with fluorescent green protein. Two of the 11 piglets glow fluorescent green from their snout, trotters and tongue under ultraviolet light, the university said.

Robin Lovell-Badge, a genetics expert at Britain's National Institute for Medical Research, said the technology "to genetically manipulate pigs in this way would be very valuable."

Lovell-Badge had not seen the research from China's cloned pigs and could not comment on its credibility. He said, however, that organs from genetically altered pigs would potentially solve some of the problems of rejected organs in transplant operations.

He said the presence of the green protein would allow genetically modified cells to be tracked if they were transplanted into a human. The fact that the pig's offspring also appeared to have the green genes would indicate that the genetic modification had successfully penetrated every cell, Lovell-Badge added.

But he said much more research and further trials - both in animals and in humans - would be necessary before the benefits of the technology could be seen.

Other genetically modified pigs have been created before, including by Scotland's Roslin Institute, but few results have been published.

Tokyo's Meiji University last year successfully cloned a transgenic pig that carries the genes for human diabetes, while South Korean scientists cloned cats that glow red when exposed to ultraviolet rays."

Superconductivity: One layer is enough



"Superconductivity Found in One-Atomic-Layer

Not long ago, a study, led by XUE Qikun, CHEN Xi, and JIA Jinfeng at Tsinghua University Dept. of Physics, in collaboration with a team headed by MA Xucun with the Chinese Academy of Sciences Institute of Physics, Prof. WANG Yayu, Tsinghua University Dept. of Physics, Prof. LIN Haiqing at the Chinese University of Hong Kong, and Prof. LIU Ying of the Pennsylvania State University Department of Physics and Material Research Institute, has found superconductivity in one-atomic-layer metal films grown on Si substrates. One-atomic-layer is the ultimate thickness a practical material can reach. The finding, published in the recent online issue of Nature Physics, renders a solution to the question concerning how thin a superconductor can be."



"Superconductivity: One layer is enough
NPG Asia Materials featured highlight | doi:10.1038/asiamat.2010.78
Published online 24 May 2010

Superconductivity has been observed in films as thin as one atomic layer.


Fig. 1: Scanning tunneling microscope image of a single atomic layer of lead (in the striped incommensurate phase) on silicon (image size is 50 nm × 50 nm).

Superconductivity is a fascinating phenomenon. The signatures of superconductivity, such as its vanishing electrical resistance and expulsion of a magnetic field, as well as its potential for diverse applications, have intrigued scientists for decades.

Nowadays, as low temperature ‘standard’ superconductors become better understood, attention has begun to focus on complex high-temperature superconductors. It is accepted that in these materials, lattice vibrations (referred to as phonons) mediate the formation of electron pairs, which is essential for the emergence of a superconducting phase. However, despite this recent trend in research, standard superconductors can still present intriguing results, as shown by Qi-Kun Xue and colleagues who have demonstrated that superconductivity can be observed even in single atomic layers of lead and indium1.

Two-dimensional (2D) superconductivity is a rather fragile state of matter. It is therefore natural to wonder what is the minimum thickness needed to observe this phenomenon, or whether a single layer of ordered metal atoms, which represents the ultimate 2D limit of a crystalline film, could be superconducting. The team studied single-layer films of lead (Fig. 1) and indium grown on Si(111). Using scanning tunneling spectroscopy at high energy resolution, they observed a region of zero conductance for low applied voltage, terminated on each side by sharp peaks — the signature of superconductivity. Furthermore, the films exhibited vortices when a magnetic field was applied, confirming the existence of a superconducting phase.

Through angular-resolved photoemission spectroscopy, the team found that for each metal the electron–phonon coupling was greatly enhanced with respect to the bulk case. This implies that the covalent silicon–metal bonding has a strong role in providing the mechanism for electron pairing, while the metal itself mainly provides the necessary carriers.

“Our work sheds new light on the mechanism of superconductivity at reduced dimensionality, especially the crucial role played by the interface,” says Xue. “The tunable atomic and electronic structures in these well-defined 2D materials provide an ideal platform for testing various theoretical models when dealing with 2D many-body physics. In addition, the exploration of one-atomic-layer superconductors grown on silicon may also help to develop superconducting electronic circuits compatible with silicon technology.”

Reference

1. Zhang, T.,1,2 Cheng, P.,1 Li, W.-J.,2 Sun, Y.-J.,1 Wang, G.,1 Zhu, X.-G.,1 He, K.,2 Wang, L.,2 Ma, X.,2 Chen, X.,1* Wang, Y.,1 Liu, Y.,3 Lin, H.-Q.,4 Jia, J.-F.1 & Xue, Q.-K.1,2* Superconductivity in one-atomic-layer metal films grown on Si(111). Nature Phys. 6, 104 (2010). | article

Author affiliation

1. Key Lab for Atomic and Molecular Nanoscience, Department of Physics, Tsinghua University, Beijing 100084, China
2. Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
3. Department of Physics and Material Research Institute, Pennsylvania State University, Pennsylvania 16802, USA
4. Department of Physics, The Chinese University of Hong Kong, Hong Kong, China
*Email: [email protected]

This research highlight has been approved by the author of the original article and all empirical data contained within has been provided by said author."

Nanomechanics: Size matters



"Strong Crystal Size Effects on Deformation Twinning

Under the guidance of her tutor, YU Qian, a post-graduate at Xi’an Jiaotong University State Key Laboratory for Mechanical Behavior of Materials, in collaboration with Prof. LI JU with University of Pennsylvania Department of Materials Science and Engineering, and Dr. HUANG Xiaoxu of Technical University of Denmark Laboratory for Sustainable Energy, made an in-depth study of the deformation twinning behavior of nano-sized metal crystals and its impact on the dynamic performance of the materials. YU and coworkers found that the size of monocrystals is of a strong effect on the dynamic performance. The finding, published in the recent issue of journal Nature, provides a meaningful insight of materials performance evaluation and design; especially on material processing at the nano-scale utilizing the strong crystal size effect."



"Nanomechanics: Size matters
NPG Asia Materials research highlight | doi:10.1038/asiamat.2010.56
Published online 12 April 2010

The deformation mechanism of single-crystal nanopillars has been shown to change dramatically at dimensions below one micrometer.


Fig. 1: A scanning electron microscopy image of a nanopillar made from a single-crystal of titanium after it has been inelastically deformed.

Reproduced from Ref. 1 © J. Sun, J. Li

As electronic devices continue to shrink in size, it is becoming increasingly important to understand mechanical deformation at microscopic scales. Inelastic deformation — a type of deformation that persists even after an applied force is removed — can lead to device failure and occur primarily through two mechanisms: deformation twinning and ordinary dislocation plasticity. The mechanism that is activated depends on whether deformations across the sample are correlated.

The origins of deformation twinning are poorly understood, as is the dependence of this mechanism on size. Now, a team of scientists from China, the US and Denmark, led by Jun Sun at Xi’an Jiaotong University and Ju Li at the University of Pennsylvania, have demonstrated that deformation twinning is completely suppressed in nanocrystals below a critical size[1].

The researchers studied the deformation of pillars made from a single crystal of a titanium alloy using compression tests. Some of the tests were conducted while the sample was being observed by transmission electron microscopy. They found that when the pillars had a diameter of less than one micrometer, deformation twinning no longer occurred. This is in sharp contrast with bulk deformation of the same alloy, which is dominated by deformation twinning, which, it turns out, is more dependent on size than the action of dislocation plasticity.

Sun, Li and their colleagues consider this strong dependence on size to arise from the collective nature of deformation twinning. Correlated deformations occur when strongly coupled defects catalyze the slip of adjacent crystal planes past one another. As the pillar diameter is reduced, defect coupling and twinning are both suppressed, leaving dislocation plasticity as the dominant mechanism for sufficiently small samples.

“The research is in its early stages,” Sun says. “It is still quite fundamental, and the connection to new technologies cannot be known with certainty at the moment.” At the same time, however, micrometer-sized pillars are commonly encountered in a range of applications, suggesting that these findings could be relevant to many devices, including micro- and nano-electromechanical systems. Future work will involve the use of high-quality electron microscopy to better understand how crystal planes slip past each other.

Reference

1. Yu, Q.,1 Shan, Z.-W.,1,2 Li, J.,3 Huang, X.,4 Xiao, L.,1 Sun, J.1 & Ma, E.1,5 Strong crystal size effect on deformation twinning. Nature 463, 335 (2010). | article

Author affiliation

1. Center for Advancing Materials Performance from the Nanoscale (CAMP-Nano), State Key Laboratory for Mechanical Behavior of Materials, Xi’an Jiaotong University, Xi’an, 710049, China
2. Hysitron Incorporated, Minneapolis, Minnesota 55344, USA
3. Department of Materials Science and Engineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
4. Danish-Chinese Center for Nanometals, Materials Research Division, Risø National Laboratory for Sustainable Energy, Technical University of Denmark, DK-4000 Roskilde, Denmark
5. Department of Materials Science and Engineering, Johns Hopkins University, Baltimore, Maryland 21218, USA
*Email: [email protected]

This research highlight has been approved by the author of the original article and all empirical data contained within has been provided by said author."

Chang'e-2 has successfully entered its trans-lunar orbit


Long March 3C rocket, carrying China's second unmanned lunar probe Chang'e II, lifts off from the launch pad at the Xichang Satellite Launch Center in southwest China's Sichuan Province, at 18:59:57 (Beijing time) on Oct. 1, 2010. (Xinhua/Li Gang)



"Jakarta Globe - Susan Stumme - ‎3 minutes ago‎
The probe successfully entered its trans-lunar orbit, Xinhua said. It will take five days for the Chang'e-2 to arrive at its lunar orbit. ... "

In celebration of Chang'e II's successful entry into its trans-lunar orbit, please enjoy the following video on China's lunar exploration program:

Live: Chang'e Speccial Report