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Statistical approach to weak signal detection and estimation using Duffing chaotic oscillators

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Science china(Information sciences) 2011年第11期54卷 2324-2337页

作者： JIN Tian & ZHANG Hua School of Electronic Information Engineering,BeiHang university,beijing 100191,{2. School of Electronic Information Engineering BeiHang University

In this paper,we describe the statistical characteristics of weak signal detection by a chaotic Duffing oscillator,and present a new method for signal detection and estimation using the largest Lyapunov *** research has shown that weak signals can be detected by a chaotic *** researchers use the Lyapunov exponent to flag the detection of a chaotic state,but our research shows that the Lyapunov exponent follows statistical characteristics,and therefore more factors should be considered in flagging chaotic weak ***,we analyze the statistical characteristics inherent in the Lyapunov exponent calculation steps,and build up a statistical model for different chaotic states based on simulation ***,we provide expressions for false-alarm and detection probabilities,selection of driving force threshold and detection of ***,we summarize the method of signal amplitude *** research indicates that the performance of the detection system is related to sampling times and intervals,in accord with the theory of statistical signal detection.

关键词： weak signal detection Lyapunov exponent chaos Duffing oscillation statistical signal process

Life cycle assessment for the "implicit" environmental impact of construction projects

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Journal of Pharmaceutical Analysis 2009年第3期21卷 167-171页

作者： Xiao-gen Shuai1,2.Hui-qiang Li1,2.Li Tang1,31. School of Civil Engineering and Mechanics,Huazhong university of Science & Technology,Wuhan 430074 2. Hubei Key Laboratory of Control Structure,Huazhong university of Science & Technology,Wuhan 430074,{2. 3. Bartlett School of graduate Study,university College London,London WC1E 6BT,UK. School of Civil Engineering and Mechanics Huazhong University of Science and Technology Wuhan 430074 China Hubei Key Laboratory of Control Structure Huazhong University of Science and Technology Wuhan 430074 China Bartlett School of graduate Study University College London London WC1E 6BT United Kingdom

The paper has established an assessment system and a quantitative calculation method of the 'implicit' environmental impact including environmental impact indicator,resources consumption indicator and energy consumption indicator. The quantitative calculation of the environmental impact indicator is based on the life cycle assessment system and the evaluation software BEES. The paper identifies normalization reference values and weights for 12.categories of the environmental impact. It also analyzes the environmental impact indicator in life cycle stages,raw materials,transportation,manufacturing,utilization,and end of life. A university refectory project is studied. The result has shown that human health,global warming and acidification are the first three environmental impacts in 12.categories. The environmental impact indicator per m2.of this project is 18.448×10-2.standard human equivalent weight. Moreover,97.3% of the total environmental impact occurs at the raw material stage,in which the most severe environmental impact is cancerous health effect; the global warming is the main impact at the transportation and manufacturing stages; the indoor air quality impact is at the usage stage.

关键词： life cycle assessment environmental impact implicit environmental impact BEES software

Numerical Analysis of Hydroforming Deep Drawing of Conical Cup

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Journal of Materials Science & Technology 2001年第1期17卷 131-132页

作者： Yongming KONG Xianbin ZHOU and Min LI Research Center of Sheet Metal Forming, School of Mechanical Engineering & Automation, beijing university of Aeronautics & Astronautics, beijing 100083, china Sch. of Mech. Eng. Beijing Univ. of Aeron. and Astron. Beijing 100083 China

Aided by the FE-code. analysis is carried to find the proper hydroforming deep-drawing condition for the perfect forming of a conical cup that can not be drawn successfully by conventional deep drawing method. Hydraulic counter pressure must be reasonably controlled, otherwise defects such as fracture and wrinkling can not be avoided. Therefore, the forming procedure is divided into three stages, and the counter pressure is adjusted intentionally to make the blank clamped onto the punch at a suitable time, then deformation at dangerous area is resisted by the effect of the counter pressure and the conical cup can be formed without defects.

关键词： Numerical Analysis of Hydroforming Deep Drawing of Conical Cup Figure

BPF-based reconstruction algorithm for multiple rotation-translation scan mode

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Progress in Natural Science:Materials International 2008年第2期18卷 209-216页

作者： Ming Chen,Huitao Zhang,Peng Zhang Computer Tomography Laboratory,Capital Normal university,beijing 100037,{2. Computer Tomography Laboratory Capital Normal University Beijing 100037 China

In industrial CT,it is often required to inspect large objects using short line-detectors. To acquire the complete CT data for the scan-ning slice of large objects using short line-detectors,some multi-scan modes have been developed. But the existing methods reconstruct-ing an image from the data scanned by multi-scan modes have to rebin the data into fan-beam or parallel-beam form via data interpolation. The data rebinning process not only increases great computational cost,but also degrades image resolution. In this paper,we propose a backprojection-filtration (BPF)-based reconstruction algorithm for rotation-translation (RT) multi-scan mode. An impor-tant feature of the proposed algorithm is that data rebinning process is not introduced. The simulation results have verified the validity of the proposed algorithm.

关键词： Backprojection-filtration Reconstruction algorithm Multiple rotation-translation scan mode Fan-beam

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双光子激发荧光各向异性度的成像

生物化学与生物物理进展 2005年第2期32卷 161-167页

作者：汪雪峰王毅蒋艳马辉清华大学物理系原子分子纳米科学教育部重点实验室北京中医药大学病理室清华大学深圳研究生院深圳518057

荧光各向异性度(fluorescence anisotropy) 测量可以获得荧光分子的转动速度信息,进而了解分子质量、结构、以及与周边环境的相互作用情况. 围绕一台双光子激发扫描荧光成像系统,通过改变外光路和图像记录与处理程序,从而实现了双光子... 详细信息

荧光各向异性度(fluorescence anisotropy) 测量可以获得荧光分子的转动速度信息,进而了解分子质量、结构、以及与周边环境的相互作用情况. 围绕一台双光子激发扫描荧光成像系统,通过改变外光路和图像记录与处理程序,从而实现了双光子激发荧光各向异性度成像,并针对一些典型样品和体系,展示了该方法的应用. 实验中观察了FITC荧光分子、FITC结合的CD44抗体分子及与肿瘤细胞表面受体结合的FITC-CD44抗体分子. 测量结果表明,不同分子质量、不同微观环境状态下的荧光分子,其各向异性度大小不同,在各向异性度图中能够被明显区分. 荧光各向异性度成像能够定量测量样品微区的各向异性度值,并以二维图像的形式直观表达,是各向异性度测量与成像技术的良好结合.

关键词：荧光各向异性度双光子扫描成像细胞膜流动性小檗碱肿瘤细胞

Molecular phylogeny and biogeography of Holcoglossum (Orchidaceae:Aeridinae) based on nuclear ITS,and chloroplast trnL-F and matK

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Molecular phylogeny and biogeography of Holcoglossum (Orchid...

An analysis of the Circumferential Grooves Casing Treatment for transonic compressor flow

中国植物学会七十五周年年会

作者： Jie Fan~(1,2. De-Zhu Li~3 Xiao-Hua Jin~(1,3) (1.State Key Laboratory of Systematic and Evolutionary Botany,& Herbarium,Institute of Botany,Chinese academy of sciences,{2. 100093,P.R.china 2.graduate School of the Chinese academy of sciences,{2. 100039,P.R.china 3.Key Laboratory for Plant Biodiversity and Biogeography,Kunming Institute of Botany,Chinese academy of sciences,Kunming 6502.4,P.R.china)

Holcoglossum is a small orchid genus yet difficult to delimit and displays a special distribution pattern in subtribe Aeridinae with two diversity centers,one in the temperate alpine region of Hengduan Mountains,north...

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Science china(Physics,Mechanics & Astronomy) 2010年第2期53卷 353-359页

作者： HUANG XuDong,CHEN HaiXin,SHI Ke & FU Song School of Aerospace,Tsinghua university,beijing 100084,{2. Tsinghua university School of Aerospace Beijing China (GRID:grid.12527.33) (ISNI:***)

The stall mechanism of the NASA Rotor 37 is investigated through the analysis of the critical flow structures near the stall under the transonic condition. The performance of the rotor with Circumferential Grooves Casing Treatment (CGCT) is also studied based on the Reynolds-Averaging Navier-Stokes approach. The study finds that stall margin improvement can be achieved without significant penalty on the efficiency for the two CGCT configurations applied. The effects of circumferential grooves on the critical flow structures are studied through the analysis of the tip leakage mass and momentum transport that further re-veal the CGCT mechanism.

关键词： transonic compressor Circumferential Grooves Casing Treatment stall margin leakage mass and momentum trans-portation analysis

Two forms of the membrane-bound state of the first C2.domain (C2.) of synaptotagminⅠand calcium-triggered membrane insertion

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Chinese Science Bulletin 2003年第17期48卷 1822-1827页

作者： HE Yuhong, LI Xianghui, WANG Fu, XUE Yi & SUI Senfang Department of Biological sciences & Biotechnology, State Key Labora-tory of Biomembrane, Tsinghua university, {2. 100084, china Department of Biological sciences and Biotechnology State Key Laboratory of Biomembrane Tsinghua University Beijing 100084 China

The synaptic vesicle protein synaptotagminⅠ (sytⅠ) is a vesicle transmembrane protein present in synap-tic vesicles, which has been proposed as the Ca2. sensor that regulates secretion. The C2. domain is the membrane proximal part of its cytoplasmic domain. The interaction between C2. and lipid bilayer has been considered to be essential for triggering neurotransmitter release. In the pre-sent work, the measurements of membrane surface tension and surface concentration showed that the C2. domain of sytⅠexhibited two membrane-bound states: the surface adsorption state and the membrane insertion state. The sur-face absorption state formed in a Ca2.-independent manner with lower affinity, while the membrane insertion state formed with high affinity was only found in the presence of Ca2.. Both the Ca2.-independent and Ca2.-dependent sytⅠ- membrane interactions required anionic phospholipids, such as phosphatidylserine (PS). When expressed into rat pheo-chromocytoma (PC12. cells and human embryonic kidney (HEK-2.3) cells, as demonstrated by immunofluorescence staining and subcellular fractionation, most of the C2. was found at the plasma membrane, even when the cells were depleted of Ca2. by incubation with EGTA. These results suggested a new molecular mechanism of sytⅠas a Ca2. sensor in membrane fusion. Ca2.-independent surface ad-sorption might attach sytⅠto the release site during the docking or priming step. When intracellular Ca2. increased, sytⅠtriggered the neurotransmitter release following the Ca2.-dependent penetration into the target membrane.

关键词：突触小泡蛋白质膜贯通蛋白质钙离子薄膜插入 C2. 薄膜边界状态

A review of recent progress in preparation of hollow polymer microspheres

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Petroleum Science 2009年第3期6卷 306-312页

作者： Wei Bin Wang Shujun Song Hongguang Liu Hongyan Li Jie Liu Ning State Key Laboratory of Heavy Oil Processing China University of Petroleum Beijing 102249 China Henan Shenma Nylon Chemical Co. Ltd Pingdingshan Henan 467013 China School of Chemical Science and Engineering China University of Petroleum Beijing 102249 China

The preparation methods of hollow polymer microspheres both at home and abroad are summarized, and their preparation mechanisms and developmental states are presented. These methods include the liquid droplet method, dried-gel droplet method, self-assembly method, microencapsulation method, emulsion polymerization method and the template method. Hollow polystyrene microspheres are the most extensively studied in the research of hollow polymer microspheres. Through comparison of the advantages and disadvantages of different preparation methods, it is concluded that microencapsulation method is most suitable for preparing polystyrene hollow microspheres.

关键词： Preparation methods hollow polymer microspheres preparation mechanism polystyrene hollow microspheres microencapsulation method