News on China's scientific and technological development.

The ABE (acetone-butanol-ethanol) fermentation was one of the largest biotechnological processes ever known, and was once ranked second only to ethanol fermentation in scale of production. Among the three main products of ABE fermentation, butanol is the most expensive, followed by acetone and ethanol.

The fluctuation of butanol price has a significant impact on the economics of ABE fermentation. Therefore, increasing the value and yield of target products, and utilization of cost-effective substrates, are expected to increase the cost competitiveness of ABE fermentation.

Clostridium beijerinckii naturally produces acetone, butanol, isopropanol and ethanol. Enlightened from this phenomenon, researchers of Dr. LI Yin’s lab at Institute of Microbiology, Chinese Academy of Sciences (IMCAS) designed an isopropanol biosynthesis module which consists of a secondary alcohol dehydrogenase gene from C. beijerinckii and a constitutive thl promoter from C. acetobutylicum.

When this module was introduced into a butanol-tolerant and butanol hyper-producing C. acetobutylicum Rh8, which was obtained in a previous work (J. Proteome Res., 2010, 9:3046-3061), the acetone was completely converted to isopropanol through the the isopropanol biosynthetic pathway. Thus, the conventional ABE fermentation was switched to IBE (isopropanol-butanol-ethanol) fermentation, which has a higher value.

Isopropanol is one of the important buck chemicals with a wide variety of usage. The global demand for isopropanol is about 2.3 million tons per year. The development of IBE fermentation process provides an alternative route for the production of isopropanol. Furthermore, the mixed alcohols (isopropanol-butanol-ethanol) have the potential to be used as biofuel.

This work has been filed for a China patent and recently published on-line in the journal Biotechnology for Biofuels (

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). The first author, DAI Zongjie, is a postgraduate student of University of Science and Technology of China and IMCAS. This work was supported by National Basic Research Program of China (973 program, synthetic cell factories) and Knowledge Innovation Program of the Chinese Academy of Sciences.

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Digital terrain analysis (DTA) on a gridded digital elevation models (DEM) is often computationally intensive. The traditional algorithms in DTA are coded as sequential program executed on a single computer processor. Therefore, the execution is often very time-consuming, especially for DEMs of large area and finer scale.

Quick calculation of DTA presents a practical challenge to personal computer (PC) users. In recent years, rapid increases in hardware capacity of the graphics processing unit (GPU) provided in modern PCs have made it possible to meet this challenge in a PC environment.

In a new study published in the journal Computers & Geosciences, Dr. QIN Chengzhi, an associate professor of geographical information science at the State Key Laboratory of Resources & Environmental Information System, Institute of Geographic Sciences & Natural Resources Research, Chinese Academy of Sciences (LREIS, IGSNRR, CAS), and one of his master students, ZHAN Lijun, parallelize two types of computationally intensive DTAalgorithms (i.e., iterative processing and recursive algorithm) on a GPU.

In the study Dr. QIN and ZHAN take the calculation of flow accumulation from gridded DEMs, one of the important DTA tasks, as example for parallelization on GPU.

This DTA task usually involves two steps in a real application: 1) using an iterative DEM preprocessing algorithm to removing the depressions and flat areas commonly contained in real DEMs, and 2) using a recursive flow-direction algorithm to calculate the flow accumulation for every cell in the DEM.

Parallel computing on GPU using a compute-unified-device-architecture (CUDA) programming model has been recently explored to speed up the execution of the single-flow-direction algorithm (SFD). However, the parallel implementation on a GPU of the multiple-flow-direction (MFD) algorithm, which generally performs better than the SFD algorithm, has not been reported.

Moreover, GPU-based parallelization of the DEM preprocessing step in the flow-accumulation calculations has not been addressed. The new study firstly designed the parallelization strategy using a GPU for the parallelization of iterative neighborhood operation in DEM preprocessing.

Then two different parallelization strategies using a GPU were explored. The first parallelization strategy, which has been used in the existing parallel SFD algorithm on GPU, was found to have the problem of computing redundancy. Therefore, Dr. QIN and Zhan designed a parallelization strategy based on graph theory.

The application results show that the proposed parallel approach to calculating flow accumulations on a GPU performs much faster than either sequential algorithms or other parallel GPU-based algorithms based on existing parallelization strategies. The parallel DEM preprocessing algorithm shows the speedup ranging from 15.9 to 22.3 times. The speedup of the proposed parallel MFD algorithm ranges from 5.8 to 10.9 times with different datasets in the test.

The method proposed in the new study, which is to change the recursive algorithm into an iterative process for better parallelizability, is also potentially useful for the parallelization of other recursive algorithms in DTA.

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China has completed the installation of the world's largest hydropower-generating unit and launched a trial, according to the China Three Gorges Corporation.

Workers are testing the generator with a capacity of 800,000 kW at the Xiangjiaba hydropower station, which is located in the lower reaches of the Jinsha River, a major headstream of the Yangtze, said a spokesman with the corporation Friday.

The trial on the unit, coded No. 8, is set to be finished by the end of July, said the spokesman.

The construction of the Xiangjiaba dam, undertaken by the corporation, started in late 2006. The first batch of its units are expected to be put into use as early as October, he said.

The dam, designed with eight 800,000-kW generators, will have a total generating capacity only following the Three Gorges Dam and the Xiluodu hydropower station in the country.

Previous reports said China is working on hydropower units with a record-breaking capacity of more than 1 million kW, expected to be put into service by 2020.

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Qiqihar Heavy CNC Equipment Co., Ltd. recently successfully develops FMB-I-26X120X60L-NC NC floor-type Boring and Milling machine tool and completed its installation and commissioning work in Wuhan Heavy Industry Qingdao HaixiHeavy Industries Co., Ltd.. This marks the Qiqihar Heavy CNC breakthrough of heavy machine equipment in the storm on the accuracy and stability, so that our field has reached a new level of ultra-heavy-duty CNC floor type boring and milling machine manufacturing...

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Nickel is one of the most important strategic and industrial resources around the world because of its wide application, but the low-grade nickel ores, such as nickel sulfide, are difficult to process with conventional flotation and smelting or bioleaching technologies.

To overcome the weaknesses, researchers with the Institute of Process Engineering, Chinese Academy of Sciences developed a new method called ammonium sulfate roasting which used to recover valuable metals from a low-grade nickel ore.

The raw low-grade nickel ore used in this study was obtained from Jinchuan Group Co. Ltd. The mineralogical composition of the nickel ore before and after roasting was carried out by XRD analysis at a scanning speed of 2°/min with Cu Kα radiation. The chemical composition of the leaching residue was analyzed using an atomic absorption spectrophotometer. The roasting-leaching experiments were carried out at a laboratory scale. Fig. 1 shows the flow sheet for the experimental procedure.

In experiments XRD analysis was conducted to understand the mechanism of roasting reaction. The results showed the amount of ammonium sulfate, roasting temperature, and roasting time are important factors that influence the dissolution of metal elements in a low-grade nickel ore.

The optimum parameters were as follows: ammonium sulfate/ore ratio, 0.8 g/g; roasting temperature, 400°C; and roasting time, 2 h. Under optimum leaching conditions, the maximum extractions of Ni, Cu, Fe, and Mg achieved are 83.48%,76.24%, 56.43%, and 62.15%, respectively.

The dissolution kinetics of Ni and Mg from the nickel ore was also studied. The results showed that the dissolution kinetics followed a shrinking core model with diffusion through a product layer as the rate-controlling step. The values of apparent activation energy were 18.782 and 10.038 kJ·mol−1 for Ni and Mg, respectively, which were consistent with the values of activation energy reported for diffusion control.

This work was financially supported by the National Natural Science Foundation of China (Nos.20876160 and 21176026). The paper was published in International Journal of Mineral Processing

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June 15, with the shield machine equipped with Chinese LYC corporation’s Shield spindle bearings, Shanghai 10th subway line’s tunnel penetrating Yili Road was finished. The era of domestic shield machine without using China-made main bearing has been ended. It indicates that China has had the alternative bearing products to abroad bearings. The domestic shield machine bearing market dominated by foreign providers has been changed.

Spindle bearings of the shield is the core component of the shield machine as affected by the use of working conditions, the strict requirements of its core technologies mastered by only a small number of well-known international enterprises.To break the monopoly of foreign countries, the development of the spindle bearings has been included in the National 863 Program...

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In late June, the rotorcraft UAVs (unmanned aircraft vehicles) developed by Shenyang Institute of Automation, the Chinese Academy of Sciences, was applied to conducting the autonomous power line inspection tasks for Liaoning Electronic Power Company Limited, State Grid.

During the operation, the rotorcraft UAVs successfully detected damages to elements after several towers being struck by lightning or discharged. The function of powerline inspection of the rotorcraft UAVs was verified through the operation, laying a solid foundation for its promotion in the future.

The operation was performed in several cities of Liaoning Province, northeast China. The rotorcraft UAVs is confronted with complicated working conditions: extensive inspection area, long transmission line, the height gap between different towers and working live.

Moreover, the transmission lines were mostly located in mountainous areas and hills, close to villages and driveways. In view of these issues, the project team came up with a new operation plan of combining autonomous flying with teleoperating, and accomplished the autonomous inspection of multi-stage towers over 220Kv.

The rotorcraft UAVs powerline autonomous inspection and erection system was jointly developed by SIA, Liaoning Electronic Power Company Limited and Jiangsu Power Transmission and Transformation Corporation.

So far, the project team has successfully conducted regular powerline inspection and erection, powerline erection in special and complex environment such as across the Yangtze River, and emergency inspection after disasters, etc

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Chinese scientists will focus on developing new quake-monitoring equipment and warning technologies, according to an agreement signed Wednesday between the country's earthquake monitoring authorities and top research institute.

In order to reduce earthquake damage, the China Earthquake Administration (CEA) and the Chinese Academy of Sciences agreed to enhance cooperation on relevant areas, including warning and auto-response systems for major infrastructure, an expedited reporting system and new sensors for earthquakes, said the agreement.

The cooperation will also cover basic research on Earth sciences, as well as the application of shock absorption and structure consolidating technologies and materials.

In 2011, the CEA and its affiliated agencies channeled 797.5 million yuan (124.8 million U.S. dollars) into scientific research and technology development, or about 19 percent of its total spending.

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World’s highest level railway wagons fatigue and vibration testing bed built in China

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