News on China's scientific and technological development.

Ferroelectric crystals, which generate the electric polarization and spontaneously enable the reverse of electric polarization by inverting the external electric field below the Cuire temperature, has long been an important topic in condensed-matter science, and its application is important as a basic element of memories devices, infrared detector and opto-electronic integrated devices, etc.

Such electro-active materials can store and switch their polarity (namely ferroelectricity) and hence exhibit piezoelectricity by interchanging electric and mechanical functions. Meanwhile, they can sensitively response to temperature changes with high dielectric constants and large pyroelectricity.

Under the excitation of intense laser radiation, novel optical phenomena such as the optical nonlinearities, electro-optic effect and photorefractive effect have also presented in ferroelectrics.

Prof. LUO Junhua and his colleagues at Fujian Institute of Research on the Structure of Matter( FJIRSM),Chinese Academy of Sciences, developed a new organic H-bonded molecular-ferroelectric, bis(imidazolium) L-tartrate, as a novel organic ferroelectric assembled by the homochiral ligand with the molecular rotator.

The complex possesses a promising large saturated polarization (1.72 μC/cm2) and small coercive field (≈1.1 kV/cm). Variable-temperature X-ray single-crystal diffraction, DSC, dielectric spectra and hysteresis loops confirmed its paraelectric-ferroelectric phase transition.

The results have been published as a communication in Angew. Chem., Int. Ed. (2012, DOI: 10.1002/anie.201200407). These findings will urge the exploration of new ferroelectrics and polar functional materials.

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The opening ceremony of the construction of the 0.3MW circulating fluidized bed pyrolysis and combustion experimental system was held in Langfang Research and Development Center of the Institute of Engineering Thermophysics, Chinese Academy of Sciences (IET, CAS). Qinggang Lv, the Deputy Director of IET and the members of this project group attended the ceremony.

The 0.3MW circulating fluidized bed pyrolysis and combustion experimental system is an important construction task in the “Char/Coal Clean and high efficient combustion technology pilot project”, which is subordinate to the strategic leading technology special projects. The construction investment budget is eight million RMB. This experimental system will be used in the research of the pyrolysis and combustion coupling characteristic of coal in the circulating fluidized bed and the pollutants emission. The construction work of the experimental system will be finished in the end of June.

The 0.3MW circulating fluidized bed pyrolysis and combustion experimental system is the first thermal test system in Langfang Research and Development Center of the Laboratory of Circulating Fluidized Bed. Another three sets of large scale thermal state test systems will be constructed by this laboratory in 2014, which will enhance its research ability in the circulating fluidized bed technology and provide strong technical support for the industrial application of the circulating fluidized bed combustion and pyrolysis technologies.

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On February 24, an expert panel from the High Technology Research and Development Center of the Ministry of Science & Technology conducted the onsite acceptance of “Dawning Thousands Terabyte Data Processing High Performance Computer System”, a subject under 863 Project jointly undertaken by ICT and Dawning Information Industry (Beijing) Co., Ltd.

In November 2011, Dawning 6000 was deployed at NSCC-Shenzhen. The system is composed of 258 cabinets containing 5600 Dawning CB60 blade servers (using dual channel Xeon X5650 processors), 2560 Nvidia Fermi C2050 acceleration cards, and 128 Dawning A840 servers, with a memory of up to 226 TB. The system is equipped with multi sets of interconnected networks, including a set of InfiniBand QDR network with a one way rate of 40Gbps and 2 sets of Gigabit Ethernet.

Dawning 6000 task force has made important breakthrough in CPU-GPU heterogeneous architecture based thousands terabyte key technology and cloud computing management software of high performance computer. The task force also conducted in-depth research of HPP architecture based Chaolong system, developed HPP architecture and controller, node operating system, integrated communication chipset and other key components. They also explored X86 and Loongson CPU hybrid heterogeneous technology. The combination of Loongson CPU with X86 software stack facilitated the compatibility of home made CPUs with mainstream commercial applications, and also laid a good technical foundation for the breakthrough in tens of thousands terabyte computing.

Ever since Dawning 6000 went into operation in NSCC-Shenzhen, it has been providing nearly 200 user groups and research entities with application services involving weather forecast, ocean data simulation, research and development of new materials and pharmaceuticals, gene research, universe evolution, and so on. Pengyun System, an independently developed system operating on Dawning 6000 has been providing institutions, enterprises and individuals with high performance, reliable and secure mass cloud storage and serving as an easy-to-use and common cloud computing service platform.

Dawning 6000 owns independent IPR in basic architecture, blade, storage system, management system, and so on. A series of key technologies of Dawning 6000 have been widely applied to high performance computers and storage systems by Shuguang Company. With greatly improved technical standard and competitive edge, Shuguang has been taking the lead in market share among Top 100 high performance computers in China.

The expert panel unanimously agreed that the subject achieved the pre-set objectives and indices, and concluded that it passed acceptance. In the meantime, they called for wider application of high performance computing and cloud computing so as to give a full play to NSCC’s role in promoting scientific and technological innovation.

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The first large well vacuum/atmosphere-protection heat treatment system, specialized for heat treatment of Nb3Sn superconducting magnet coils, has been recently installed in the High Magnetic Field LAb (HMFL) in Hefei, China. This heat treatment system is designed for the heat treatment of Nb3Sn coils made from the Cable in Conduit Conductor (CICC) to form the Nb3Sn superconducting magnet.

The system can also be used for high temperature heat treatment of other large-scale coils.Currently, only a few countries, including USA, Japan, and Republic of Korea, have similar equipments. The successful Research & Development of this equipment breaches a gap in superconducting magnet technology in China and provides the basis for further development and production of large-scale Nb-Sn superconducting magnets.

The heat treatment system, jointly developed by CHMFL and BEIJING SEVENSTAR ELECTRONICS CO., LTD, composed mainly the furnace, the purging gas supply system, the control system, and the gas impurities monitoring system. The purging gas supply system includes the gas flowing pipes system for the conductor, the vacuum system for the conductors, the vacuum system for the furnace, etc. The gas flowing pipes system can be used for the cleaning of conductor’s internal part, as well as the realization of automatic control of the gas flux in the conductor during the atmosphere protected process.

The gas flowing pipes system provides 7 pipe lines for gas flowing inside the conductor, which allows for simultaneous heat treatment of 7 groups of conductors. In order to reduce the cleaning time of the conductor, the vacuum system is used to clean the internal part of the Nb-Sn conductor until a relatively high base vacuum is achieved. The vacuum system for the furnace adopts two vacuum units, each consistes of a oil diffusion pump, a roots pump and two mechanical pump. The vacuum degree is higher than 1×10-3 Pa in the furnace.

Installation and callibration of the heat treatment system is focused on the important technical parameters, and all parameters meet or exceed specifications. The cold state vacuum degree is higher than 8×10-4 Pa, and the hot state vacuum degree exceeds 1×10-3 Pa, with a pressure rising rate under 0.005 Pa/h. Under atmosphere protection, the furnace temperature homogeneity (inside a cylindrical region of 2.5 m diameter and 2.5 m height) is less than ±5℃.

For vacuum condition, temperature homogeneity isless than ±3℃. Temperature homogeneity is the most important factor for the heat treatment of large-scale Nb-Sn coils. Our test results suggest that the temperature homogeneity, either under Ar gas protection or vacuum condition, reaches a very high level.

The heat treatment system design incorporated many innovative techniques. For example, it can be operated in two modes, which can be switched directly from one to the other during the heat treatment process. In order to achieve higher temperature homogeneity, soaking and the ventilation equipment are used in the furnace to allow for a homogeneity on par with international standard.

Successful R&D of this equipment will guarantee the smooth construction of the "Static High Magnetic Field Device" under the national grand scientific project of the Eleventh-Five-Year Plan. Additionally, it will provide an important technological equipment for the future development and applications of Nb-Sn superconducting magnets in China.

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More than 60 researchers from a joint group from China and the United States have finished the world's first pear genome sequence, one of the seven agencies involved said Wednesday.

The research achievement laid the basis for developing higher yielding, good quality and low-cost pear breeds and provided the data for comparing the genes between other fruits in the rosaceae family and also studying their evolution, the Beijing Genomics Institute (BGI) said in a press release.

Zhang Shaoling, head of the research group and also a professor at Nanjing Agricultural University, said the genome sequencing will help to study the pear's resistance to pests and environmental stress as well as the regular pattern of pear trees' growth.

The sequencing program was launched in April 2010.

China is the world's largest producer of pears, accounting for over 60 percent of the world's total output. Pears are also the country's third most widely grown fruit after apples and oranges.

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In May 13, 2012, scientific and technological achievements appraising meeting of “Calcium Ion Optical Frequency Standard” was hold in Wuhan by Chinese Academy of Sciences. The achievement was completed by Wuhan Institute of Physics and Mathematics (WIPM, CAS). The director of the commission of identification is Prof. Li Tianchu of NIM (the academician of CAE), and the vice director is Prof. Wang Yiqiu of Peking University.

The commission of identification listened carefully to the technical summary report supplied by project team and measurement report offered by testing team. And the experts carefully reviewed the technology of sci-tech novelty search report, application situation report and intellectual property report, etc. Besides these, the experts did the site inspection.

The commission of identification spoke highly of the work of calcium ion optical frequency standard. They considered this calcium ion optical frequency standard is the first optical frequency standard of China, and the achievement reaches the international advanced level. The commission of identification agreed this calcium ion optical frequency standard passed appraisal.

They suggest the department concerned support sequentially this project, and the experts hope the performance of the calcium ion optical frequency standard can be further improved to satisfy the national majorfundamental and concerned application requirements.

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Recently, Group led by Zhao Baosheng developed a new type of X-ray modulator and an X-ray detector based on MCP which are respectively the launcher and receiving systems. It realized the experiment of new space X-ray communication method.

In 1895, the German physicist W.K. Roentgen discovered X-ray whose wave is short but has strong penetrability and it could make a lot of invisible solid materials give off visible fluorescence. Therefore, X-ray has been widely used in medical perspective and nondestructive inspection. Actually, as short-wave electromagnetic wave, X-ray could also transmitted in space and successfully realize the function of communication.

At present, the research of space wireless communication has been adopted in many fields, for instance, airwave, microwave, infrared, visible light and ultraviolet, otherwise, the utilization of X-ray communication research is blank. Consequently, it has important scientific meaning and good application prospects to study a new concept space communication method based on X-ray.

With short wave and strong penetrability, the transmittance of X-ray is 100% when its photon energy is greater than 10 kilo electron volt (wavelength short than 0.12nm.) and the atmospheric pressure is below 10-1 Pascal, its transmission has hardly any weakening. It means very low transmitting power could realize distance space communication.

So compared with other electromagnetic wave such as microwave and laser, X-ray is equipped with good directivity, low transmitting power, distant transmission range, strong confidentiality, free from EMI of space environment and wide communication band. All these merits may help to realize satellite time communication.

In 2007, the astrophysicists of Goddard Space Flight Center of NASA Keith Gendreau proposed to use X-ray to realize point communication among satellite spacecrafts. This concept was considered “the new space communication method of next generation”.

The X-ray modulator developed by Zhao Baosheng Group is a combination of vacuum triode and X-ray tube technologies and it realizes high speed modulation of X-ray energy. In theory, the bandwidth of an emission could reach to 50GHz. Meanwhile, since the X-ray detector based on MCP has advantages such as rapid response, great receiving area and small lowest detectable power, when the divergent angle of X-ray is less than 2 milliradian, its photon energy is more than 20 kilo electron volts and the transmitting power is 100 milliwatt, it could transfer over 6000 km in the space.

For now, XIOPM has established X-ray digital transmission verification system which is based on voice communication, mainly including X-ray launching and receiving devices. It has already realized the voice communication under the OOK and PWM modulation systems and the communication speed could reach to 64 kbps in a 6m vacuum line.

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HIT Center for Composite Materials and Structures (CCMS)’ paper Carbon Nanotubes: Super-Stretchable Spring-Like Carbon Nanotube Ropes (DOI: 10.1002/adma.201290124) was published in the international journal Advanced Materials (May 30 2012, volume 21), and its diagram was selected as the journal’s back cover. According to the journal’s reviewer, this paper offered a very intriguing nanostructure.

This paper, written by Professor HE Xiaodong’s research group, presented the carbon nanotube spring, which can sustain very large tensile strains (up to 285%, the conventional CNT fiber has only 5%-10%) by loop separation and straightening without structural failure.

The steel springs are mechanical parts with elasticity. They are widely used in mechanics to control machine parts, store energy (as elastic potential energy) and measurement force.

This springy carbon nanotube ropes have an unparalleled advantage over conventional springs with a maximum elongation of 285%; they maintain stable spring constant (100N/m）and electrical conductivity after 1000 tensile cycle when the tensile strain is 20%. In addition, they has less density, better flexibility as well as enhanced electrical conductivity and elastic energy.

This new kind of carbon nanotube spring thus has a huge potential for application in retractable electrodes, miniature strain sensors and energy dissipation fibers.

Advanced Materials is a leading weekly material science journal with an ISI 2010 IF of 10.88 (+30% on 2009). It contains carefully selected top-quality reviews and research news from the cutting edge of the chemistry and physics of functional materials. Articles in Advanced Materials continue to be heavily cited after they are published, with a 5-Year Impact Factor over 11.

This paper, receiving funding from the National Natural Science Foundation of China, was finished by Professor HE Xiaodong, LI Yibin, CAO Anyuan and their PhD student Ms SHANG Yuanyuan.

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Recently, a research team co-led by Maosheng Yao, a researcher at Peking University College of Environmental Science and Engineering, and Jue Zhang, an associate professor from the College of Engineering, achieved a major breakthrough in bioaerosol inactivation using non-thermal plasma.

Their paper, “Rapid Inactivation of Biological Species in the Air using Atmospheric Pressure Non-thermal Plasma,” was published in Environment Science and Technology.(ES&T)

Airborne biological particles are ubiquitous in the environment; they include a variety of microorganisms (bacteria, fungi, and viruses), allergens, plant debris, endotoxin, glucans and skin scales. Exposure to those pathogenic microbes or derivatives is shown to cause numerous adverse health effects.

The outbreaks of SARS in 2003 and influenza H1N1 viral infections in 2009 prompted global attention on effective biological monitoring and control measures. There are at least 1,800 bacterial types of environmental bioaerosols and some of them are of bioterrorism significance.

Over the past decades, different types of technologies have been investigated for inactivation of biological agents, including traditional filter membrane, ultraviolet and microwave radiation, but the inactivation rate remains to be a great challenge.

Peking University researchers generated non-thermal plasma (the “Fourth State of Matter” that is electric neutrality, which contains atoms that are partly deprived of electron and ionized gas that is ionized from atom) using their self-designed DBD system, and inactivated bacteria and fungi with remarkable high efficiency within milliseconds of treatment.

Research shows that most of the bacteria break into pieces when the air with different kinds of bacteria passes through the non-thermal plasma generating system, an inactivate rate of more than 98% for B. subtilis, which is believed to be very resistant to the environmental stress and are often used as a surrogate for anthrax. The bioaerosol exposure to the non-thermal plasma causes not only inactivation, but also cell wall and DNA damage. Moreover, research shows that non-thermal plasma has a good removal rate for chemical species such as HC and NO.

The non-thermal plasma has potential for wide applications for air sterilization in hospitals, high value buildings, military bases, flight cabins and other public health facilities.

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