News on China's scientific and technological development.

Various usable energy sources are always the research focus concerning the petroleum depletion crisis and rising fuel prices. Coal tar are abundantly produced every year by coal carbonization and gasification but poorly used owing to its defects in physical and chemical properties.

Researchers with Institute of Process Engineering (IPE) developed an upgrading process for coal tar application as an energy fuel for combustion. They produced clean liquid fuel from the catalytic hydrogenation of coal tar using two serial fixed beds.

In their work, hydrofining and hydrocracking catalysts with different metal loadings were prepared, which were filled in the first and second fixed beds, respectively, where hydrogenation of coal tar distillate used as feedstock was performed. The entire reaction system was mainly made up of three units, that is, the reactant feeding unit, the hydrogenation unit, as well as the product separation and collection unit.

The effect of pressure on the hydrogenation performance was also investigated. The catalysts showed good stability in activity in the test of catalyst life.

The analysis results of the products indicated that raw coal tar could be promisingly upgraded by catalytic hydrogenation. Gasoline fraction with low sulfur and nitrogen contents of 39 and 13 ppm and diesel fraction with 43 and 9 ppm were obtained, as compared to the respective values of 0.96 and 1.69 wt % in the feedstock.

Analyses revealed that the gasoline and diesel products mainly comprised substituted cyclohexanes, substituted and partially saturated naphthalenes, and saturated paraffins. As compared to other previous studies, a relatively lower hydrogen pressure of 6 MPa was successfully applied to obtain good-quality products.

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Researchers in China have applied graphene as transparent conducting layers (TCLs) in vertical light-emitting diodes (VLEDs) made from indium gallium nitride (InGaN) semiconductors. The researchers were based in Beijing at Chinese Academy of Sciences’ Institute of Semiconductors and Tsinghua University.

Although the use of graphene as a TCL has begun to be explored recently, the application has generally been to more traditional lateral LEDs where the nitride epitaxial material remains attached to its sapphire growth substrate.

In a lateral LED, the n- and p-type electrodes are on the same side of the device away from the electrically insulating substrate. The current flow path is therefore partly lateral as it flows through the LED to create light emission.

In the new research, the sapphire substrate was removed using a laser lift-off process to allow vertical current flow from n- and p-type electrodes on opposite sides of the LED chip. In theory, such an arrangement could allow much higher-performance devices, although there is some way to go to make such LEDs more competitive.

One particular problem is the blocking of light output by the metal contacts used to deliver current to the devices. This could be improved by current-spreading layers to re-distribute light output away from the contact region using TCLs such as indium tin oxide (ITO) or graphene.

One disadvantage of ITO is poor transparency at shorter wavelengths such as those produced by nitride semiconducting devices (blue-UV). Another problem with ITO is the high cost of indium. Graphene has better transparency characteristics but, apart from being more experimental, its electrical conductivity also tends to be lower.

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The result of using graphene (G-VLED) rather than ITO (R-VLED) is a 25% increase in light output. The researchers comment: “The light output improvement of G-VLEDs can be attributed to the higher conductivity of graphene than that of u-GaN. In addition, due to the injection current-spreading characteristics of graphene, G-VLEDs have relatively uniform current distribution, preventing the current accumulating below the N-electrode...”

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In eary August this year, maize armyworm invaded some parts of Northeast China. According to reports from the Departments of Civil Affairs of Liaoning Province and Jilin Province, up until 9 a.m, August 14, about 1,109,000 people had suffered from the plague, and infested area had amounted to 302,800 hectares in four cities and counties around the city of Shenyang, Liaoning Province and seven counties and districts in Jilin Province. Of the infested area, about 30,000 hectares yielded zero, causing economic loss of around 790 million RMB (about 124,346,000 USD).

In view of the severe situation of this year's plague, researchers from Shenyang Institute of Automation, the Chinese Academy of Sciences (SIA) headed for Woniushi Township in Shenyang's Faku County on August 12. They found out that almost all the corn leaves in the fields had been eaten out by worms.

Meanwhile, traditional artificial pesticide spraying method helped very little in battling the worms but can do harm to the health of farmers. In Houjiapu Village only, the infested area amounted to around 2,500 acres.

The project team tailored an operation plan according to the situation, and accomplished pesticide spraying over a large area on the premise of guaranteeing the spraying effect. During the operation, the rotorcraft UAVs (unmanned aircraft vehicles) developed by SIA conducted super low altitude and high density trace pesticide spraying at one meter height above the crops.

This method can avoid direct body contact to the pesticide so that the safety of farmers can be guaranteed to the largest degree. It took the rotorcraft UAVs only half an hour to finish spraying pesticide of more than 20 acres corn field, while normally it would take two to three days for one person to finish the task.

After the operation, on-site confirmation of the spraying effect was made, showing that the rotorcraft UAVs demonstrated obvious advantages in atomization effect, spraying efficiency and insecticidal effect, etc.

The pesticide spraying operation this year is the second time for the rotorcraft UAVs to be used in real application, after its first variable-rate pesticide spraying flight experiment in the Fourth Division of Xinjiang Production and Construction Corp last year.

It further verifies the actual operation capability of the system when faced with breaking disaster, demonstrates the system's advantages and irreplaceability, and lays solid foundation for its promotion and application in the future.

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Independent innovation is a long-held strategy at State-owned Datang Telecom Technology & Industry Group, which continues its quest to upgrade China's telecommunication industry and help it reach international market competence, said the group's spokesman Liu Huiya.

Liu said Datang shares Zhongguancun Haidian Science Park's rich resources in talent, well-equipped infrastructure, services, and large markets for technology and products.

Together the elements "ensure a superior investment climate and great development potential", he noted.

Datang is the initiator and key intellectual property rights holder of patents for the homegrown 3G standard TD-SCDMA that "put an end to the long market dominance in the mobile telecommunication industry by Western giants", said Liu.

The company has also been a market leader in promoting commercialization of the technology.

By making a number of key breakthroughs in chips and panels, Datang has created China's first home-developed full industry chain in the mobile telecommunication industry.

In January, China's proposal of TD-LTE-Advanced technology was determined by the International Telecommunication Union to be one of 4G international mobile communication standards Datang is the major patent owner of that standard.

Another home-developed telecommunication technology, TDD is increasingly accepted by mobile operators around the world.

The development and promotion of TD-SCDMA 3G, TD-LTE and TD-LTE-A 4G technologies will "lay a solid foundation for China to improve its global competitiveness over the next 10 years in the mobile telecommunication industry", Liu said.

Datang is also advanced in its outlook on patents. The group has now applied for more than 13,000 patents worldwide. Its number of invention patents is among the top of all enterprises across the nation.

With many national key projects, the group will continue to improve its R&D system in the future years to improve efficiency and quality, said Liu, while increasing its investment in technical innovation, especially in the design and development of core equipment, chips, mobile Internet and smart terminal devices.

By promoting the commercialization of its TD-SCDMA 3G and TD-LTE technologies at home and overseas, it will also take an active role in global restructuring of the mobile telecommunication market.

In addition, it is moving into other fields such as the Internet of Things, and has made achievements using its TD technologies to meet the demands of different businesses, said the spokesman.

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