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Conference on Sensors and Smart Structures technologies for Civil, Mechanical, and Aerospace Systems 2010

作者： Yu, Yan Wang, Yang An, Yonghui Ou, Jinping Dalian Univ Technol Sch Elect Sci & Technol Dalian 116024 Peoples R China Harbin Inst Technol Sch Civil Engn Harbin 150090 Peoples R China Dalian Univ Technol Sch Civil Engn Dalian 116024 Peoples R China

ISBN: (纸本)9780819480620

Smart material structure originated from aerospace area has been a research hotspot in the application of civil engineering, shipping, and so on. For structural health monitoring of civil engineering, the research about high-performance sensing unit of smart material structure is very important, and this will possibly push further the development of health monitoring and diagnosis technique. As one of the piezoelectric materials belonging to smart materials, PVDF(Polyvinylidene Fluoride) film is widely concerned for its property advantages of low cost, good mechanical ability, high sensibility, resistance of corrosion. In this paper, for the validation of using PVDF for sensing unit for structural local monitoring of civil engineering, an experimental system of PVDF sensor for structural local monitoring on a bridge model is built. Based on the operating mechanism of PVDF, its measure circuit and characteristics(quasi-static and dynamic strain responding) are introduced. A bridge model is designed, and experiments have also been done for structural local health monitoring using PVDF. The experimental results show that, PVDF can finish impact response monitoring and damage detection of a bridge model, and the developed experimental system with simple and easy implement can be used for practical monitoring engineering.

关键词： PVDF smart material structural local monitoring bridge model experimental system

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Advances in estimation methods of vegetation water content based on optical remote sensing techniques

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Science china(technological Sciences) 2010年第5期53卷 1159-1167页

作者： ZHANG JiaHua1,XU Yun1,YAO FengMei2,WANG PeiJuan1,GUO WenJuan1,LI Li1 & YANG LiMin3 1 Chinese Academy of Meteorological Sciences,Beijing 100081,china 2 Graduated University of Chinese Academy of Sciences,Beijing 100049,china 3 USGS/EROS Data Center,South Dakota 57198,USA Chinese Academy of Meteorological Sciences Beijing China Graduated University of Chinese Academy of Sciences Beijing China USGS/EROS Data Center South Dakota USA

Quantitative estimation of vegetation water content(VWC) using optical remote sensing techniques is helpful in forest fire as-sessment,agricultural drought monitoring and crop yield *** paper reviews the research advances of VWC retrieval using spectral reflectance,spectral water index and radiative transfer model(RTM) *** also evaluates the reli-ability of VWC estimation using spectral water index from the observation data and the *** on two main definitions of VWC-the fuel moisture content(FMC) and the equivalent water thickness(EWT),the retrieval accuracies of FMC and EWT using vegetation water indices are ***,the measured information and the dataset are used to estimate VWC,the results show there are significant correlations among three kinds of vegetation water indices(i.e.,WSI,NDⅡ,NDWI1640,WI/NDVI) and canopy FMC of winter wheat(n=45).Finally,the future development directions of VWC detection based on optical remote sensing techniques are also summarized.

关键词： optical remote sensing vegetation water content estimation method water index FMC EWT radiative transfer model

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Spreading and direction of Gaussian-Schell model beam through a non-Kolmogorov turbulence

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OPTICS LETTERS 2010年第5期35卷 715-717页

作者： Wu, Guohua Guo, Hong Yu, Song Luo, Bin Beijing Univ Posts & Telecommun Sch Elect Engn Beijing 100876 Peoples R China Peking Univ CREAM Grp State Key Lab Adv Opt Commun Syst & Networks Beijing 100871 Peoples R China Peking Univ Inst Quantum Elect Sch Elect Engn & Comp Sci Beijing 100871 Peoples R China Beijing Univ Posts & Telecommun Minist Educ Key Lab Informat Photon & Opt Commun Beijing 100876 Peoples R China

We show that the far-field beam spreading and direction of partially coherent Gaussian-Schell model (GSM) beams are independent on the spatial coherence of the source through non-Kolmogorov atmospheric turbulence, which has potential applications in long-distance free-space optical communication. The effects of spatial coherence, exponent value alpha, and inner scale and outer scale of atmospheric turbulence on beam spreading are studied in details. The GSM beam has greater spreading for smaller inner scale or bigger outer scale through non-Kolmogorov turbulent atmosphere. (C) 2010 Optical Society of America

关键词： Atmospheric turbulence Coherence Free space optics Laser communications Power spectra Turbulence

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CeO_2-supported vanadium oxide catalysts for soot oxidation:the roles of molecular structure and nanometer effect

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Journal of Rare Earths 2010年第2期28卷 198-204页

作者：刘坚赵震徐春明段爱军姜桂元 State Key Laboratory of Heavy Oil Processing China University of Petroleum

The nanometer CeO2 powder was prepared by the method of microwave-assisted heating hydrolysis,and the nanometer CeO2-supported or ordinary CeO2-supported vanadia catalysts with different vanadium loadings(atomic ratios:100V/Ce=0.1,1,4,10,and 20) were prepared by an incipient-wetness impregnation *** techniques(XRD,FT-IR,Raman and UV-Vis DRS) were utilized to characterize the structures of VOx/CeO2 *** results showed that the structures of CeO2-supported vanadium oxide catalysts de...

关键词： vanadium oxide catalyst CeO2 nanometer soot combustion rare earths

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Significantly improved dehydrogenation of LiBH₄ destabilized by TiF₃

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ENERGY & ENVIRONMENTAL SCIENCE 2010年第4期3卷 465-470页

作者： Guo, Y. H. Yu, X. B. Gao, L. Xia, G. L. Guo, Z. P. Liu, H. K. Fudan Univ Dept Mat Sci Shanghai 200433 Peoples R China Univ Wollongong Inst Superconducting & Elect Mat Wollongong NSW 2522 Australia

The hydrogen storage properties of LiBH4 ball milled with TiF3 were investigated. It was found that the LiBH4-TiF3 mixture exhibited significantly improved dehydrogenation properties. For example, the LiBH4-TiF3 (mole ratio: 3 : 1) sample started to release hydrogen at around 100 degrees C, and the hydrogen desorption capacity reached 5.0 wt% at 250 degrees C. Furthermore, the dehydrogenated product can be partially rehydrogenated at 100 atm H-2 and 350 degrees C. X-Ray diffraction (XRD), infrared (IR) spectroscopy and X-ray photoelectron spectroscopy (XPS) characterizations revealed that the decreased dehydrogenation conditions in the LiBH4-TiF3 system resulted from an exothermic reaction of 3LiBH(4) + TiF3 -> 3LiF + TiB2 + B + 6H(2), which improved both its thermodynamics and kinetics. As the above reaction is exothermic, the reverse reaction is not feasible, further investigations indicated that the rehydrogenation may be due to the formation of another borohydride.

关键词： Lithium compounds

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Diversity of bile salt hydrolase activities in different lactobacilli toward human bile salts

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ANNALS OF MICROBIOLOGY 2010年第1期60卷 81-88页

作者： Jiang, Jinkang Hang, Xiaomin Zhang, Min Liu, Xianglong Li, Daotang Yang, Hong Shanghai Jiao Tong Univ Sch Life Sci & Biotechnol MOE Key Lab Microbial Metab Shanghai 200240 Peoples R China Shanghai Jiao Da Onlly Co Ltd Inst Biomed Shanghai 200233 Peoples R China

This study was conducted to evaluate the diversity of bile salt hydrolase (BSH) activities in eight species of lactobacilli. BSH activities were quantified based on the amount of taurine or glycine liberated from six main human bile sodium salts [glycocholic, glycodeoxycholic, glycochenodeoxycholic, taurocholic (TC), taurochenodeoxycholic, taurodeoxycholic] and a mixture of bile salts that resembled human bile. The eight species differed in their BSH activities. Specifically, Lactobacillus helveticus, Lactobacillus fermentum and Lactobacillus gallinarum had the ability to deconjugate taurine-conjugated bile salts, but not glycine-conjugated bile salts, which suggested that microbial BSHs recognize bile salts on both the cholate steroid nucleus and the amino acid moiety. Of the eight species evaluated, Lactobacillus acidophilus strains exhibited the highest specific BSH activity toward human bile salts, with the exception of TC. In addition, the L. acidophilus specific BSH activity toward glycine-conjugated bile salts was ten times higher than that toward taurine-conjugated bile salts. Moreover, the specific BSH activity of Lactobacillus plantarum did not vary significantly toward different bile salts, and Lactobacillus gasseri Am1 exhibited higher specific BSH activity toward TC than other lactobacilli. A comparison of bsh genes indicated that the LA-bshA, LA-bshB, LG-bsh and LP-bsh1 genes that encode the BSH enzymes are highly homologous (higher than 45%), while the LP-bsh2, LP-bsh3 and LP-bsh4 genes, which might not encode BSH enzymes, had lower similarity (lower than 26.3%).

关键词： Lactobacillus Bile salt hydrolase Human bile salts Secondary bile acid

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Identification and functional characterisation of the promoter of the calcium sensor gene CBL1 from the xerophyte Ammopiptanthus mongolicus

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BMC PLANT BIOLOGY 2010年第1期10卷 1-16页

作者： Guo, Lili Yu, Yanhua Xia, Xinli Yin, Weilun Beijing Forestry Univ Coll Biol Sci & Biotechnol Natl Engn Lab Tree Breeding Beijing Peoples R China

Background: CBL1 is a calcium sensor that regulates drought, cold and salt signals in Arabidopsis. Overexpression of CBL1 gene in Arabidopsis and in Ammopiptanthus mongolicus showed different tolerant activities. We are interested in understanding the molecular mechanism of the upstream region of the CBL1 gene of A. mongolicus (AmCBL1). We investigated and characterized the promoter of the AmCBL1 gene, for promoters play a very important role in regulating gene expression in eukaryotes. Results: A 1683-bp 5' flanking region was isolated from A. mongolicus. The sequence was identified as AmCBL1 promoter. Analysis of the promoter sequence indicated a 690-bp intron and some basic cis-acting elements were related to various environmental stresses and plant hormones. To identify the functional region of the AmCBL1 promoter, five plant expression vectors fused with the GUS (beta-glucuronidase) gene, driven by series deleted fragments of AmCBL1 promoter at different lengths from -1659, -1414, -1048, -296 to -167 bp relative to the transcriptional start site were constructed and transformed into Nicotiana tabacum L. cv. 89. Functional properties of each promoter segment were examined by GUS staining and fluorescence quantitative analyses using at least three single-copy PCR-positive plants of transgenic tobacco, treated with various environmental stresses and plant hormones for different times. We demonstrated that the AmCBL1 promoter was a vascular-specific and multiple-stress-inducible promoter. Our results further imply that the promoter fragment B1S3 possessed sufficient essential cis-acting elements, accounting for vascular-specific and stress-induced expression patterns. It may also indicate that for response to some stresses certain cis-elements are required in tissues outside the region of the B1S3 construct. Conclusions: To help resolve uncertainties about the upstream regulatory mechanism of the CBL1 gene in desert plants, we suggest that the function of the AmCBL

关键词： Transgenic Tobacco Desert Plant Distinct Gene Expression Profile Promoter Segment CBL1 Gene

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Effect of zinc additions on the microstructure mechanical properties and creep behavior of as-cast Mg-3Sm-0.4Zr (wt.%) alloy

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MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING 2010年第18-19期527卷 4605-4612页

作者： Zheng, Jiang Wang, Qudong Jin, Zhengli Peng, Tao Shanghai Jiao Tong Univ Natl Engn Res Ctr Light Alloys Net Forming Sch Mat Sci & Engn Shanghai 200240 Peoples R China Shanghai Jiao Tong Univ State Key Lab Met Matrix Composites Sch Mat Sci & Engn Shanghai 200240 Peoples R China

The influence of zinc (Zn) additions (0, 0.5, 1 wt.%) on the microstructure, mechanical properties of as-cast Mg-3Sm-0.4Zr (wt.%) alloy has been investigated in the present study. Compared with the Zn-free alloy, addition of 0.5 wt.% Zn results in the formation of great amounts of fine precipitates in the regions close to grain boundaries, which effectively retard dislocation motion and dramatically enhance the tensile strength at 200 and creep resistance. For the alloy containing higher zinc content (=1 wt.%), the excellent creep resistance is mainly attributed to the suppression of non-basal dislocation slip due to the presence of planar defects. (C) 2010 Elsevier B.V. All rights reserved.

关键词： Magnesium alloy Tensile properties Creep Microstructure

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Toward Stable and Realistic Haptic Interaction for Tooth Preparation Simulation

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JOURNAL OF COMPUTING AND INFORMATION SCIENCE IN ENGINEERING 2010年第2期10卷 021007页

作者： Wu, Jun Wang, Dangxiao Wang, Charlie C. L. Zhang, Yuru Beihang Univ State Key Lab Virtual Real Technol & Syst Beijing 100191 Peoples R China Chinese Univ Hong Kong Dept Mech & Automat Engn Shatin Hong Kong Peoples R China

In this paper, we present the methods to generate a stable and realistic simulator for dental surgery. First, a simplified force model is derived from grinding theory by considering the complex bur shape and dental handpiece's dynamic behavior. While the force model can be evaluated very fast to fulfill the high update rate of haptic rendering, it also explains basic haptic sensation features in tooth preparation operation. Second, as direct rendering of this damping-like force model may induce instability of the haptic device, we apply a virtual coupling based method to guarantee the stability in haptic rendering. Furthermore, implicit integration of the bur's motion equation is utilized to ensure numerical stability. Third, to overcome force discontinuity caused by locally removing tooth materials, we define a two-layer based representation for the bur, where the boundary voxels are adopted to compute forces and the interior voxels are employed to remove materials from teeth. The experimental results agree with the real sensation described by experienced dentists. [DOI: 10.1115/1.3402759]

关键词： haptic rendering grinding/drilling force model dental simulator voxel model

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Cross immunity of DNA vaccine pVAX1-cSZ2-IL-2 to Eimeria tenella, E. necatrix and E. maxima

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EXPERIMENTAL PARASITOLOGY 2010年第3期124卷 330-333页

作者： Shah, Mohammed Ali A. Xu, Lixin Yan, Ruofeng Song, Xiaokai Li, Xiangrui Nanjing Agr Univ Coll Vet Med Nanjing 210095 Jiangsu Peoples R China

The study describes cross protection experiments with chimeric DNA vaccine pVAX1-cSZ2-IL-2 to determine its efficacy against four important Eimeria species. Seven-day-old chickens were randomly divided into nine groups;group I negative control, groups 2, 3, 4, 5 positive controls;and groups 6, 7, 8 and 9 experimental groups. On days 7 and 14, groups 1-5 were injected with TE buffer, and groups 6-9 with the vaccine. At 21 days of age, all chickens were inoculated with 5 x 10(4) sporulated oocysts except for the negative control. Groups 2 and 6 were inoculated with Eimeria tenella, groups 3 and 7 with Eimeria necatrix, groups 4 and 8 with Eimeria acervulina and groups 5 and 9 with Eimeria maxima. Seven days later, all chickens were weighed and slaughtered to obtain intestinal samples. Efficacy of immunization was evaluated on the basis of oocyst decrease ratio, lesion score, body-weight gain and anti-coccidial index. The results indicated that the recombinant plasmid can induce host immune responses by alleviating intestinal lesions, body weight loss and oocyst ratio and imparting good protection against E. tenella and E. acervulina, medium protection against E. necatrix but little effect against E. maxima. It is concluded that the conserved antigen can provide cross protection and should be explored further. (C) 2009 Elsevier Inc. All rights reserved.

关键词： Eimeria cSZ-2 DNA vaccine Cross protection

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