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A fingerprint feature extraction algorithm based on curvature of Bezier curve

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Progress in Natural Science:Materials International 2007年第11期17卷 1376-1381页

作者： Yuan Huaqiang1. Ye Yangdong2, Deng Jianguang2, Chai Xiaoguang1.and Li yong1.1. School of Software, Dongguan University of Technology, Dongguan 523808, China 2. Information Engineering Institute, Zhengzhou University, Zhengzhou 450001. China) School of Software Dongguan University of Technology Dongguan 523808 China Information Engineering Institute Zhengzhou University Zhengzhou 450001 China

Fingerprint feature extraction is a key step of fingerprint identification. A novel feature extraction algorithm is proposed in this paper, which describes fingerprint feature with the bending information of fingerprint ridges. Ridges in the specific region of fingerprint images are traced firstly in the algorithm, and then these ridges are fit with Bezier curve. Finally, the point that has the maximal curvature on Bezier curve is defined as a feature point. Experimental results demonstrate that this kind of feature points characterize the bending trend of fingerprint ridges effectively, and they are robust to noise, in addition, the extraction precision of this algorithm is also better than the conventional approaches.

关键词： fingerprint identification feature extraction Bezier curve curvature

Biological aspects on the cultures of the entomophthoralean fungus Pandora delphacis grown on broomcorn millets

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Science Bulletin 2003年第17期48卷 1816-1821页

作者： FENG Mingguang1.2 & LIANG yong1.1. Institute of Microbiology, College of Life Sciences, Zhejiang Univer-sity, Hangzhou 31.029, China 2. Institute of Applied Entomology, College of Agricultural Sciences and Biotechnology, Zhejiang University, Hangzhou 31.029, China Institute of Microbiology College of Life Sciences Zhejiang University Hangzhou 310029 China

A novel method was developed to use glutinous broomcorn millets (Panicum miliaceum L.) as solid substrate to make cultures of the entomophthoralean fungus Pandora delphacis specifically pathogenic to planthoppers, leafhop-pers and aphids. Steamed millets with water content of 45% were inoculated with a liquid culture of P. delphacis at a ratio of 20% (v/w) and then incubated at 25℃ and L:D 1.:1.. The millets cultured for 3—1. d exhibited high potential for co-nidial production. The 5-d-old millet culture sporulated most abundantly, discharging up to 1..1. (1.31. 1.4 conidia/ millet. The cultures incubated for 7—1. d also had a satis-factory sporulation capability, yielding 1..00—1..90 1.4 conidia/millet. Compared to 2.32 (0.34) 1.4 conidia dis-charged from each of Myzus persicae adults killed by P. del-phacis and a ≤60-h duration of sporulation, each of the millets cultured for 5—1. d produced 5.6—7.4 times more conidia with an over doubled duration for conidial discharge (1.4 h). Among 1.6 M. persicae adults exposed to the shower of conidia discharged from the cultured millets, a total mor-tality of 69.8% caused by P. delphacis infection was observed within 7 d after exposure, but no death was attributed to the fungal infection in the aphids unexposed. The results indi-cate that the millet cultures of P. delphacis are biologically similar to aphid cadavers killed by the same fungus. Due to the superiority of the cultured millets to the cadavers in sporulation potential and duration, the method for making cultures of P. delphacis on the broomcorn millets is highly recommended for use in study of entomophthoralean fungi for microbial control. This is the first report on the success of the solid culture of Pandora species on cereals.

关键词： entomophthorales Pandora delphacis broomcorn millets solid culture sporulation capability aphid infectivity.

Comparison of photovoltaic devices based on MEH-PPV with various molecular weights

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Chinese Science Bulletin 2004年第21期49卷 2259-2261页

作者： KANG Bonan1.2, WANG Liduo1. YANG yong1.& QIU yong1.1. Key Laboratory of Organic Optoelectronics & Molecular Engineering of Ministry of Education, Department of Chemistry, Tsinghua Univer- sity, Beijing 1.0084, China 2. State Key Laboratory on Integrated optoelectronics, Jilin University Region, Changchun 1.0023, China Key Laboratory of Organic Optoelectronics & Molecular Engineering of Ministry of Education Department of Chemistry Tsinghua University Beijing 100084 China

Polymer photovoltaic devices based on poly (2- methoxy-5-(2′ -ethyl-hexyloxy)-1.4-phenylene vinylene) (MEH- PPV) with three weight-average molecular weights (Mw) have been fabricated with the device structure of ITO/PEDOT/ MEH-PPV/Ca/Ag, and the effect of the molecular weight on photovoltaic properties has been investigated. The experi- mental results show that the high molecular weight of MEH- PPV leads to low series resistance (Rs) and high short-circuit current. The low molecular weight of MEH-PPV leads to high shunt resistance (Rsh) and high open-circuit voltage. When the molecular weight is 6×1.5, the highest power con- version efficiency was observed.

关键词： MEHPPV 分子量光电器件载流子迁移率串联电阻并联电阻聚(2-甲氧基-5-(2'-乙基-乙氧基)-1.4-亚苯基乙烯撑)

Study on Soil and Water Loss Characteristic of the Railway Construction in Mountain Area

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地球科学进展 2004年第S1期19卷 232-237页

作者： BAI Ming-zhou~1. XU Zhao-yi~1. HUO Yu-hua~1. DONG yong~2 (1. School of Civil Engineering and Architecture of Beifing JiaoTong University, Beijing 1.0044,China 2. Personnel Division of the First Railway Survey & Design Institute, Lanzhou 730000, China)

The factor of human project activity is often the immediate cause resulting in soil and water loss. The Baoji-Lanzhou second railway in construction is an example. The soil and water loss law caused by earth and stone mountain railway engineering construction in the northwestern China is studied systematically and that caused possibly by the road bed project, the road moat project, the field project, the tunnel project and the service road project in construction is probed. At the same time, the type, t...

关键词： Mountain railway Soil and water loss Characteristic.

On Some Species Extinction in the Nonautonomous n -Competing Pecies Systems

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Systems Science and Systems Engineering 1999年第3期9卷 267-276页

作者： CHEN Bo\|shan\+1. \ LIU yong\|qing\+2 1. Department of Mathematics, Hubei Normal University, Huangshi 435002, China 2. Department of Automatic Control Engineering South China University of Technology Guangzhou 51.641

We generalize and unify some recent results about extinction in nonautonomous n \|species competitive Lotka\|Volterra system. We exhibit new algebraic criteria which guarantee that any solution with strictly initial values that is positive has the property that some of its components vanishes while other approaches a certain solution of their isolate subsystem.

关键词： lotka\|volterra system asymptotic behaviors extinction coexistence

Matching Strategies and Fuzzy URLs in Web Based Component Retrieving

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Wuhan University Journal of Natural Sciences 2001年第Z1期6卷 283-287页

作者： Wang Ying 1.2 , Sang Da yong 2, 3 1. College of Management, Xi’an Jiaotong University, Xi’an 71.049,China 2.College of Engineering, Air Force University of Engineering, Xi’an 71.038,China 3. State Key Laboratory of Software Engineering, Wu College of Management Xi’an Jiaotong University Xi’an China College of Engineering Air Force University of Engineering Xi’an China State Key Laboratory of Software Engineering Wuhan University Wuhan China

The World Wide Web (WWW) has greatly changed the way of component based software reuse, for large number of components provided by different vendors become available and it's rather difficult to find and choose what we in fact need. To make large amount of the components collaborate, an information exchanging model is essential. In order to retrieve and search the suitable or usable components more effectively, some techniques should be taken into account. Among these techniques, matching strategies and fuzzy URL semantics are significant for the former help us to find components which could be reused and the other both to broaden the searching areas and use some uncertain information to make the searching more purposive. A brief discuss on an abstract component model (UACModel) is begun, which was proposed to promote the interoperability and information exchange among various reusable component libraries (RCLs), and a framework for component retrieval. Then the emphases are put on some matching strategies, especially incomplete ones that encourage reuse through component customization, and fuzzy URL extensions to be supported and realized.

关键词： component reuse interoperability model component retrieval index repository reusable component library (RCL)

Ordinal scheduling problem and its asymptotically optimal algorithms on parallel machine system

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Science in China(Series F) 2004年第2期47卷 161-169页

作者： TAN Zhiyi1.2 & HE yong1.1. Department of Mathematics, Zhejiang University, Hangzhou 31.027, China (email: tanzy@math.zju. *** heyong@math.zju.***) 2. State Key Laboratory of CAD & CG, Zhejiang University, Hangzhou 31.027, China Department of Mathematics Zhejiang University State Key Laboratory of CAD & CG Zhejiang University

Focusing on the ordinal scheduling problem on a parallel machine system, we discuss the background of ordinal scheduling and the motivation of ordinal algorithms. In addition, for the ordinal scheduling problem on identical parallel machines with the objective to maximize the minimum machine load, we then give two asymptotically optimal algorithm classes which have worst-case ratios very close to the upper bound of the problem for any given m. These results greatly improve the results proposed by He yong and Tan Zhiyi in 2002.

关键词： scheduling design and analysis of algorithm worst-case ratio.

ACIDIC FIBROBLAST GROWTH FACTOR （aFGF） REDUCES POSTISCHEMIC RENAL INJURY IN RATS

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中华创伤杂志 1996年第2期 73-78页

作者： FU Xiao bing 1. Cuevas P 2, Gimenez Gallego G 2, TIAN Hui min SHENG Zhi yong 1. Trauma Center of Postgraduate Medical College, 304th Hospital, 51.Fu Cheng Road, Beijing 1.0037, China 2. Servicio de Histologia, Hospital Universitario Ramon

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关键词： INJURY FIBROBLAST GROWTH ACIDIC POSTISCHEMIC RATS REDUCES RENAL FACTOR aFGF

Gas formation mechanism of marine carbonate source rocks in China

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Science China Earth Sciences 2005年第4期48卷 441-453页

作者： ZHAO Wenzhi1. WANG Zhaoyun1. HE Haiqing2, ZHANG Mingjie3, WANG Hongjun1. WANG Yunpeng4 & QIN yong5 1. Research Institute of Petroleum Exploration & Development, PetroChina, Beijing 1.0083, China 2. PetroChina Exploration & Production, Beijing 1.001., China 3. Department of Geology, Lanzhou University, Lanzhou 730000, China 4. Guangzhou Geochemical Institute, Chinese Academy of Sciences, Guangzhou 51.640, China 5. China University of Mining and Technology, Xuzhou 221.00, China Research Institute of Petroleum Exploration & Development PetroChinaBeijin China PetroChina Exploration & Production Beijing China Department of Geology Lanzhou University Lanzhou China Guangzhou Geochemical Institute Chinese Academy of Sciences Guangzhou China China University of Mining and Technology Xuzhou China

By breaking through the conventional ideology on the study of gas-formation mechanism of source rocks which focused on merely the characteristics of source rocks them- selves, and based on the development and distribution characteristics of marine carbonate source rocks in the medium-to-bottom parts of the Chinese superimposed sedimentary basins as well as various processes in the course of gas generation and reservoir forming, the complex hydrocarbon-generating model of carbonates is established. Such a model concerns not only the “three-stage” gas formation characteristics of carbonates, but also the gas generation process due to a thermal cracking of oil and the re-generation process of gas from heated secondary organic matters during the gas-generation and reservoir-forming course. The high-quality hy- drocarbon generating matter of marine carbonate source rocks determined a high gas-oil ratio and tended to form paleo-oil-reservoirs, representing an enrichment process of organic matters. The thermal cracking of oil in palaeo-oil-reservoirs is an important means for the effective forma- tion of gas reservoirs. The secondary organic matters in carbonate reservoirs may regenerate gas after a secondary deep burial, thus becoming an effective gas source.

关键词： carbonate, three-stage hydrocarbon generation, inhibitive effect of maturity, oil-cracking gas, second-ary asphalt gas.