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comprehensive characterization of indoor airborne bacterial profile

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Journal of Environmental Sciences 2009年第8期21卷 1148-1152页

作者： P. L. chan P. H. F. y. y. W. cheng c. y. chan P. K. Wong Department of Biology The Chinese University of Hong Kong Department of Applied Biology.and chemical Technology The Hong Kong Polytechnic University Department of Microbiology The Chinese University of Hong Kong

This is the first detailed characterization of the airborne bacterial profiles in indoor environments. Two restaurants were selected for this study. Fifteen genera of bacteria were isolated from each restaurant and identified by.three different bacterial identification sy.tems including MIDI, Biolog and Riboprinter. The dominant bacteria of both restaurants were Gram-positive bacteria in which Micrococcus and Bacillus species were the most abundant. Most bacteria identified were representative species of skin and respiratory.tract of human, and soil. Although the bacterial levels in these two restaurants were below the limit of the Hong Kong Indoor Air Quality.Objective （HKIAQO） Level 1 standard （i.e., 〈 500 cfu/m^3）, the majority.of these bacteria were opportunistic pathogens. These results suggested that the identity.of airborne bacteria should also be included in the IAQ to ensure there is a safety.guideline for the public.

关键词： airborne bacterial profile bacterial identification indoor air quality

High-temperature Oxidation Resistant coatings composed of y.Z Particles Packaged by.Nano-Al_2O_3 Film

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中国腐蚀与防护学报 2009年第4期29卷 316-317页

作者： y. D. HE c. REN K. ZHANG Beijing Key.Laboratory.for corrosion Erosion and Surface Technology University of Science and Technology Beijing 100083 Beijing China

The alloy.performance to resist high-temperature oxidation is mainly.determined either by.the formation of oxide scales or by.the deposition of oxide coatings on the surface of *** the former case,a protective oxide scale,such as Al_2O_3,cr_2O_3 and SiO_2,can be selectively.formed by.adjusting the composition of *** if the oxide scale on the surface of alloy. is spalled,new oxide can grow continuously.so the oxidation of alloy. can be inhibited *** the latter case,theoretically. depositing oxy.en diffusion barrier oxide coatings,such as Al_2O_3,cr_2O_3 and SiO_2,can prevent alloy. from oxidation as ***,the integrity.of these oxide coatings can not maintain for a long time,owing to the thermal stress produced by.the difference of the expansion coefficients between the oxide coatings and alloy.***,the ability.to resist high-temperature oxidation by.depositing such oxide coatings should be ***,an oxide coating possessed both properties to act as an excellent oxy.en diffusion barrier and match a suitable expansion coefficient with alloy.substrate,is the basic conditions for the coating to maintain the ability.to resist high-temperature oxidation of alloy.. Based on above-mentioned idea,a novel composite oxide coating has been developed to obtain two kinds of functions,to act as an oxy.en diffusion barrier and to adjust the expansion coefficient of coating as *** 1 shows the schematic diagram of such novel oxide *** coating is composed of ZrO_2-8%y.2O_3(y.Z) particles packaged by.nano-Al_2O_3 *** nano-Al_2O_3 film has a bubble-like structure,each y.Z particle is packaged in an Al_2O_3 *** to y.Z is a good conductor for oxy.en ions,so oxy.en diffusion in this composite coating is determined by.the walls of Al_2O_3 bubbles or the nano-Al_2O_3 *** the thickness of all walls of Al_2O_3 bubbles in the direction perpendicular to the surface of alloy.is over a critical

关键词：金属腐蚀三氧化二铝防护

Study.on ceramic photonic bandgap structure with three-dimensional diamond lattice

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Journal of University.of Science and Technology.Beijing 2006年第5期13卷 461-464页

作者： Haiqing y.n Wenbin cao y. Miy.moto Material Science and Engineering School University of Science and Technology Beijing Beijing 100083 China Joining and Welding Research Institute Osaka University Osaka 567-0047 Japan

A novel process, which was based on powder injection molding, was investigated for the fabrication of ceramic photonic bandgap structure with three-dimensional diamond lattice. The SiO2-TiO2 ceramic powder was mixed with a water-soluble agent to produce slurry. The slurry.was then injected into an epoxy.mold with inverse diamond lattice, fabricated by.the stereolitographic rapid prototy.ing process. To increase the density.of the green compact, cold isostatic pressing was applied on the unit. Using thermal debinding, the water-soluble agent and the epoxy.were extracted at 360 and 650 K, respectively. Sintering was immediately.done at 950 K for 5 h and the desired three-dimensional ceramic structure was obtained. The calculated band diagram for this structure indicated the existence of an absolute photonic bandgap for all wave vectors. At 14.7-18.5 GHz, a complete band gap was located with a maximum attenuation of 30 dB at 17 GHz, when transmission was measured in the 〈100〉 direction between 10 and 20 GHz.

关键词： photonic cry.tals (Pcs) powder injection molding ceramic powder diamond lattice

LINEARIZATION OF A NONLINEAR PERIODIc BOUNDARy. cONDITION RELATED TO cORROSION MODELING

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Journal of computational Mathematics 2007年第6期25卷 645-660页

作者： y. S. Bhat S. Moskow Institute for Mathematics and its Applications Univ. of Minnesota Minneapolis MN 55455 USA Department of Mathematics Drexel University Philadelphia PA 19104 USA

We study.galvanic currents on a heterogeneous surface. In electrochemistry. the oxidation-reduction reaction producing the current is commonly.modeled by.a nonlinear elliptic boundary.value problem. The boundary.condition is of exponential ty.e with periodically.vary.ng parameters. We construct an approximation by.first homogenizing the problem, and then linearizing about the homogenized solution. This approximation is far more accurate than both previous approximations or direct linearization. We establish convergence estimates for both the two and three-dimensional case and provide two-dimensional numerical experiments.

关键词： Galvanic corrosion Homogenization Nonlinear elliptic boundary.value problem Butler-Volmer boundary.condition Robin boundary.condition.

Regulation of Hedgehog signaling by.ubiquitination

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Frontiers in Biology 2015年第3期10卷 203-220页

作者： Elaine y. c. Hsia y.rui Gui Xiaoy.n Zheng Department of Anatomy.and Regenerative Biology George Washington University School of Medicine and Health SciencesWashington DC 20037 USA

The Hedgehog （Hh） signaling pathway.play. crucial roles both in embry.nic development and in adult stem cell function. The timing, duration and location of Hh signaling activity.need to be tightly.controlled. Abnormalities of Hh signal transduction lead to birth defects or malignant tumors. Recent data point to ubiquitination-related posttranslational modifications of several key.Hh pathway.components as an important mechanism of regulation of the Hh pathway. Here we review how ubiquitination regulates the localization, stability.and activity.of the key.Hh signaling components.

关键词： Hedgehog signaling ubiquitination

Simultaneous characterization of multiple properties of solid and liquid phases in cry.tallization processes using NIR

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Particuology 2011年第6期9卷 589-597页

作者： chao y. Ma Xue Z. Wang Institute of Particle Science and Engineering School of Process Environmental and Materials Engineering University of Leeds Leeds LS2 9JT UK

Near infrared spectroscopy.（NIR） is now probably.the most popular process analy.ical technology.（PAT） for pharmaceutical and some other industries. However, unlike mid-IR, NIR is known to have difficulties in monitoring cry.tallization or precipitation processes because the existence of solids could cause distortion of the spectra. This phenomenon, seen as unfavorable previously. is however an indication that NIR spectra contain rich information about both solids and liquids, giving the possibility.of using the same instrument for multiple property.characterization. In this study. transflectance NIR calibration data was obtained using solutions and slurries of varied solution concentration, particle size, solid concentration and temperature. The data was used to build calibration models for prediction of the multiple properties of both phases. Predictive models were developed for this challenging application using an approach that combines genetic algorithm （GA） and support vector machine （SVM）. GA is used for wavelength selection and SVM for mode building. The new GA-SVM approach is shown to outperform other methods including GA-PLS （partial least squares） and traditional SVM. NIR is thus successfully.applied to monitoring seeded and unseeded cooling cry.tallization processes of L-glutamic acid.

关键词： Process analy.ical technology.Near infrared spectroscopy.Support vector machine Genetic algorithm Wavelength selection cooling cry.tallization

Extraction of affine invariant features for shape recognition based on ant colony.optimization

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Journal of Sy.tems Engineering and Electronics 2011年第6期22卷 1003-1009页

作者： y.xing Mao ching y. Suen Wei He State Key.Laboratory.of Power Transmission Equipment ＆ Sy.tem Security.and New Technology Chongqing University Chongqing 400044 E R. China centre for Pattern Recognition and Machine Intelligence Concordia University Montreal QC H3G 1M8 Canada

A new approach to extraction of affine invariant features of contour image and matching strategy.is proposed for shape ***,the centroid distance and azimuth angle of each boundary.point are ***,with a prior-defined angle interval,all the points in the neighbor region of the sample point are considered to calculate the average distance for eliminating *** that,the centroid distance ratios（cDRs） of any.two opposite contour points to the bary.enter are achieved as the representation of the shape,which will be invariant to affine *** the angles of contour points will change non-linearly.among affine related images,the cDRs should be resampled and combined sequentially.to build one-by.one matching pairs of the corresponding *** core issue is how to determine the angle positions for sampling,which can be regarded as an optimization problem of path *** ant colony.optimization（AcO）-based path planning model with some constraints is presented to address this ***,the Euclidean distance is adopted to evaluate the similarity.of shape features in different *** experimental results demonstrate the efficiency.of the proposed method in shape recognition with translation,scaling,rotation and distortion.

关键词： shape recognition affine transformation centroid distance ratio(cDR) ant colony.optimization(AcO) path planning.

Analy.is of ground vibrations due to underground trains by.2.5D finite/infinite element approach

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Earthquake Engineering and Engineering Vibration 2010年第3期9卷 327-335页

作者： Hsiao-Hui Hung y. B. y.ng center for Research on Earthquake Engineering （NcREE） Taipei 10617 Chinese Taipei y.nlin University.of Science and Technology Douliu Yunlin 64002 Chinese Taipei

The 2.5D finite/infinite element approach is adopted to study.wave propagation problems caused by.underground moving trains. The irregularities of the near field, including the tunnel structure and parts of the soil, are modeled by.the finite elements, and the wave propagation properties of the far field extending to infinity.are modeled by.the infinite elements. One particular feature of the 2.5D approach is that it enables the computation of the three-dimensional response of the half-space, taking into account the load-moving effect, using only.a two-dimensional profile. Although the 2.5D finite/infinite element approach shows a great advantage in study.ng the wave propagation caused by.moving trains, attention should be given to the calculation aspects, such as the rules for mesh establishment, in order to avoid producing inaccurate or erroneous results. In this paper, some essential points for consideration in analy.is are highlighted, along with techniques to enhance the speed of the calculations. All these observations should prove useful in making the 2.5D finite/infinite element approach an effective one.

关键词： ground vibrations 2.5D finite/infinite element underground train wave number wave propagation

Directly.Modulated 10 Gb/s Signal Transmission over 320 km of Negative Dispersion Fiber for Regional Metro Network

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光学学报 2003年第S1期23卷 533-534页

作者： H. S. chung y. G. Jang y. c. chung 1 Korea Advanced Institute of Science and Technology.373-1 Gusong-dong Yusong-gu Daejon 305-701 Korea2 Samsung Electronics 94-1 Imsudong Gumi KyungBuk 730-350 KoreaKorea Advanced Institute of Science and Technology 373-1 Gusong-dong Yusong-gu Daejon 305-701 Korea

We demonstrate the transmission of directly.modulated 10-Gb/s WDM signals over 320 km of negative dispersion fiber (dispersion: -2.5 ps/km/nm @1550 nm) without dispersion compensation. The results indicate that a regional metro WDM network could be implemented cost-effectively.by.using the proposed negative dispersion fiber and direct modulated lasers.

关键词： of in et over Directly.Modulated 10 Gb/s Signal Transmission over 320 km of Negative Dispersion Fiber for Regional Metro Network WDM for