News on China's scientific and technological development.

A production line based on the built in Changzhou, Jiangsu, to manufacture high-capacity NI-MH batteries of wide-temperature range, was put on stream on May 18, 2012.

The project is based on the technology developed by the Changchun Institute of Applied Chemistry (CIAC), CAS. For years, the CIAC has been devoted to exploring and industrializing the NI-MH batteries. The scientists broke through the core technology of the hydrogen storage alloy of wide temperature range, and developed the high-capacity NI-MH batteries of wide-temperature range with independent intellectual property.

The products on this line are geared to the needs of the nation’s transportation and nation safety construction, especially applicable for electric vehicles, solar and wind power plants in cold regions. It is estimated that 10,000,000 batteries would be produced per year, the sales of which would reach 30,000,000RMB.

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A research team of Peking University (PKU) has recently achieved breakthrough in the scaling and statistical properties studies of high Mach number compressible turbulence. Led by Chen Shiyi, professor in the State Key Laboratory for Turbulence and Complex Systems (SKLTCS), and He Xiantu, physicist in the Center for Applied Physics and Technology (CAPT), the team obtained accurate high Mach number turbulent fields with high-accuracy numerical simulation and analyzed the underlying physical process in the compressible turbulence. The results were published by Physical Review Letters on May 25, 2012.

High Mach number turbulence is of great importance to a large number of industrial applications and natural phenomena, including high-temperature reactive flows, combustion, transonic and hypersonic aircrafts, space exploration and astrophysics. Recently, the high Mach number turbulence and its mechanism become a hot area for turbulence research.

The research method of high Mach number compressible turbulence is quite different from that of weakly compressible and incompressible turbulence. Usually, the influence caused by the variation of density is neglected in the research of weakly compressible turbulence, therefore the models for incompressible turbulence studies are also suitable for weakly compressible turbulence research. However, those models are not suitable for the modest and high Mach number turbulence, of which compressibility is obvious. For a long time, scientists haven’t found efficient tools to study and analyze the high Mach number compressible turbulence.

Professor Chen Shiyi and his group obtained the accurate high Mach number turbulent fields by numerical simulations with high accuracy. In addition, with the multi-process decomposition, they found the scaling of the shear and dilation process, as well as the statistic properties of their interaction.

As the one-dimensional simplified model of turbulence, the statistic of the behavior of Burgers turbulence (“Burgulence”) is an attractive subject for physicist and mathematicians. Although scientists have realized there is some linkage between Burgers turbulence and the compressible turbulence, the strict proof for the linkage hasn’t been proposed.

Professor Chen Shiyi and his group analyzed the dilation equations for Burgers turbulence and compressible turbulence, and showed the influence of pressure on the probability density function of the dilation. So a perfect explanation for the similarities and difference between Burgers turbulence and compressible turbulence is presented.

"This work is an important progress in the research of turbulences, and has a far influence on the research work in the future,” said Chen.

This work is supported by the National Natural Science Foundation of China, the National Science and Technology Ministry under a subproject of the 973 Program, and CAPT at PKU.

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The U.S. once again has the most powerful supercomputer in the world, thanks to the U.S. Department of Energy's Sequoia, according to the latest edition of the Top500 supercomputer list, ending Asia's hold on the top spot. Sequoia's 1.57 million processor cores can perform 16.32 petaflops (quadrillion floating-point calculations per second).

The U.S. lost the supercomputer throne to the Chinese Tianhe-1A supercomputer in November 2010. That, in turn, was surpassed by the Japanese K Computer, which held on to the number one spot for two editions of the twice yearly list. The K Computer, able to perform 10.51 petaflops on its 705,024 Sparc64 processing cores, is now in second place, while Tianhe-1A has slipped to fifth place.

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Related Content Sequoia is an IBM BlueGene/Q system powered by Power BQC 16-core processors running at 1.6GHz. It runs Linux. The DOE's National Nuclear Security Administration announced Sequoia's construction in February 2009. The computer is installed at the Lawrence Livermore National Laboratory, and has been upgraded since it appeared at 17th place in last November's ranking.

Following Sequoia and the K Computer is a new U.S. system, the Argonne National Laboratory's Mira. It is another IBM BlueGene/Q system with 786,432 cores, capable of 8.16 petaflops.

The top U.S. system on the previous list, Jaguar, is now in sixth place.

The latest list is a big win for the U.S. But it also marks a return of European systems in force, according to the list's authors. Europe has more supercomputers in the top ten than any other continent, with four systems that are all making their debut on the list.

The fastest European supercomputer is Germany's SuperMUC, capable of 2.9 petaflops using 147,456 processor cores. It is installed at the Leibniz Rechenzentrum. In fourth place, it is the highest-placed system on the list to use Intel processors.

The other European supercomputers on the top ten are Italy's Fermi (seventh place), Germany's JuQUEEN (eighth) and France's Curie thin nodes (ninth).

For China, the latest Top500 list is less uplifting; the Tianhe-1A system and the Nebulae have dropped from second and fourth place to fifth and 10th.

The U.S. is still the leading continent with 252 of the 500 systems on the list, followed by Asia with 121 and Europe with 106 systems. The latter two grew their shares, while the U.S share dropped by 11 systems compared to the November list.

Overall, the Top500 list saw a big boost in performance, with a total computing capacity of 123.4 petaflops, up from 74.2 petaflops on the November list and 58.7 petaflops one year ago.

But more performance often means more power consumption too. The average power consumption of a Top500 system is 671.3 kW, up from 634 kW six months ago and 543 kW one year ago. Sequoia is not only the fastest of the supercomputers, but also one of the most energy-efficient, at around 2 Gflops/watt, a characteristic it shares with the other BlueGene/Q systems on the list.

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Yangjiang 3 is the latest Chinese nuclear power reactor to see the emplacement of its containment dome.

China Guangdong Nuclear Power Corporation (CGNPC) reported the major lift, which took took only 76 minutes to carry out, on 9 June. The company is leading the construction of the Yangjiang plant, which is planned to eventually feature six reactors using the CPR-1000 technology. It will be operated by the Daya Bay Nuclear Power Operations and Management Company - a joint venture with Hong Kong's China Light and Power. The company already manages the Daya Bay, Ling Ao and Ling Ao Phase II nuclear power plants

Construction at Yangjiang began with unit 1 in December 2008. Work at unit 2 was started in August 2009 and at unit 3 in November 2010. Construction of unit 4 was meant to have started in early 2011, but this was suspended pending the results of a post-Fukushima analysis by Chinese safety authorities. Two further units are planned for Yangjiang but their schedules have also been subject to review.

Units 1, 2 and 3 are slated to begin commercial operation in 2013, 2014 and 2015, respectively.

Construction projects already underway should see China bring online some 27 new reactors by the end of 2015 - in addition to the 15 units currently in operation.

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The Jiaolong, China's manned deep-sea submersible, made a second dive into the Mariana Trench Tuesday, setting a new national record by reaching a depth of 6,908 meters below sea level.

The dive, which started at 7 a.m. local time (2100 GMT Monday) after the leaking oil pipe of its hydraulic system had been repaired, is expected to re-check the hydraulic system and test various functions and the security of the submersible at great depths.

After setting a new national record in the Mariana Trench, located in the western Pacific Ocean and the deepest part of the world's oceans, sea drivers are collecting water samples and placing markers on the sea floor.

Last Friday, the vessel reached 6,671 meters below the sea in the first dive, well surpassing the previous record of 5,188 meters made last July.

The Jiaolong will attempt four more dives, aiming to move deeper and deeper to pursue the goal of reaching 7,000 meters below the sea level between mid-June and early July.

The Xiangyanghong 09, the vessel's oceanographic mother ship, reached the designated dive zone in the Mariana Trench on June 11.

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Xi’an Koja Photoelectric Technology Co., Ltd. had participated in the construction of VTS-120 Horizontal Vacuum Annealing Furnace. Deliberated and proved by Technology Transformation Office, it officially has come into use recently. After examination, each index of it had met the design requirements and it could satisfy the annealing demand of the whole institute. It means that XIOPM is capable to do vacuum heat treatment to titanium castings.

VTS-120 Horizontal Vacuum Annealing Furnace is composed of vacuum furnace body, heating system (furnace pipe), vacuum system, reverse air cooling system, water-cooling system, feeding system, electrical control system and alarm system. The vacuum furnace body is a water-cooling system with double-decked jackets; the heating elements are arranged evenly in circle direction and separated to three sections for independent heating, the three-point of temperature control makes sure the temperature uniformity; the vacuum system is composed of triplex pump vacuum air-removed system and vacuum measurement.

With clean, economic, pollution-free, non-oxidation and small deformation characters, the annealing furnace can not only apply in the vacuum annealing of titanium castings and others but also in the stress relieving and machining and non-oxidation bright annealing of aluminum and other alloys. Meanwhile, it is also applicable to the vacuum annealing of the materials with operation temperature below 800℃

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As a third-generation semiconductor material, GaN is now widely applied in optoelectronic fields, such as light emission diodes (LEDs), ultraviolet detectors, laser diodes (LDs) and high electron mobility transistors (HEMT). Besides, due to its advantages of high radiation resistance and good chemical stability, GaN also has excellent potentials in nuclear radiation detection. There was few investigation of GaN for X-ray detection until recently, which will bring a great prospect of Fe-doped GaN based X-ray detectors due to its very low leakage current.

Dr. LU Min's team applied the Fe-doped GaN wafer supplied by Suzhou Nanowin Science & Technology Co.,Ltd and succeeded in fabricating the prototype device of X-ray photoconductive detectors. The detectors have vertical structure with upper and lower electrodes. With the applied bias as high as 200V, the ratio of X-ray photo current to dark current is up to 180 without shading environment. And clear X-ray scanning imaging of hexagonal steel nuts can be realized applying our detecors. Besides, the research paper about the detector has been published in the magazine “Physica Status Solidi: Rapid Research Letters" (No. 5–6, 187–189 (2011) / DOI 10.1002/pssr.201105163). One reviewer considered that this study is interesting and does highlight the potential of Fe doped GaN for radiation detection. It is known that, it is the first-time that X-ray detectors based on Fe-doped GaN photoconductors was internationally reported.

This study is supported by the National Natural Science Foundation of China (Grant No. 10875084), the Natural Science Foundation of Jiangsu Province (Grant No. BK2008174) and the Applied Science Foundation of Suzhou

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Chinese researchers have succeeded in transferring gallium nitride (GaN) light-emitting diodes (LEDs) grown on a layer of silicon to a layer of copper. The new copper substrate enabled the GaN crystals to release some of the internal stresses generated when they originally formed. This relaxation helped minimize the so-called "quantum confined stark effect," a vexing problem for LEDs that reduces their efficiency.

In comparison with LEDs on silicon substrates, the light output of LEDs on copper was enhanced by 122 percent. The relocation of the LEDs produced no obvious deterioration in the crystals' light-emitting region, known as multiple quantum wells.

The researchers attributed the improvements in efficiency to the removal of the absorptive substrate; the insertion of a metal reflector between the LEDs' structure and the copper submount; the elimination of electrode shading, which also reduces efficiency; and the rough surface of the exposed buffer layer, which improves crystal orientation on the substrate.

The results are reported in a paper accepted for publication in the American Institute of Physics' journal Applied Physics Letters.

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Scientists, at the Research Centre for Biomedical Information Technology of the Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, recently have overcome technological barriers of radar based life detector. Through new algorithms, the life signal detector (LSD) designed by Chinese scientists has the advantages of high resolution, high accuracy, wide frequency detection range and low power consumption, which is among one of the best in the world.

According to the introduction by Dr. Ye Li, the director of the Research Centre for Biomedical Information Technology, LSD adopts the radar detection method, which has strong penetration and precise positioning abilities. New LSD can detect the trivial motion and breathing activities by human faraway. It can also provide the precise location information with the error in centimeters only, and implement real time tracking. Even under the conditions of super weak life signal, harsh environment and heavy interference, the LSD still can catch and detect life signal, which will win more time for life rescue after disaster.

Now, the prototype has been developed in the lab in Shenzhen. In the near future, it will be widely used in many fields, such as disaster rescue and smuggler detection. At that time, the customers in China can buy a domestic LSD which will be more advanced than foreign one with only half price.

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After the development of 400W and 600W industrial fiber lasers, Xi’an Sino-Maiman Laser Technology Co., Ltd., the new incubated enterprise of XIOPM, has recently successfully developed the first domestic 1000W industrial fiber laser with independent intellectual property rights and preliminary developed integration capability of laser processing system combining with the lasers it produced. The industrialization of this scientific achievement will meet the market demand of high power fiber lasers in the industrial processing field, meanwhile, it makes great contribution to break the situation that foreign countries monopolize the market and promote the further development of fiber laser processing of our country.

The 1000W industrial fiber laser developed by Xi’an Sino-Maiman Laser Technology Co., Ltd., CAS-SM-HPEF-1000W, adopts the advanced special fiber technology, pumping coupler technology, FBG inscription technology and LD fiber coupler technology and highly realizes the fiber integration. Small laser spots with high brightness and light beam that close to diffraction limit, high turnover rate, good heat dissipation, small in size, stable performance, high liability, high environmental fitness, convenience and agility for use, all these advantages of it can satisfy the industrial processing applications.

The main technological merits of the products: 1) the output power could be adjusted continuously from 200w to 1000W; 2) it has continuous and modulate pulse output modes; 3) electricity and optic control is highly integrated, lasing when plugged; 4) it has high stability, the output power fluctuation is less than 1% when with the full load; 5) it is equipped with red laser function; 5) with LNC output, it is convenient for machine tool using; 6) it is easy to be operated and maintenance-free. The application fields: 1) laser cutting, drilling and welding; 2) laser quenching, cladding; 3) scientific research.

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