3,606 research outputs found

    Separation and extraction of bridge dynamic strain data (in Chinese)

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    Through comparing the measured data of dynamic strains due to loading and temperature by the strain gauge and temperature sensor at the same location, the information in the strain data was divided into three parts in the frequency domain by using the defined index named PSD (power spectra density)- ratio. The three parts are dominated respectively by temperature varying, stresses and noises and can be distinguished from the determined values of the separatirix frequencies. Then a simple algorithm was developed to separate the three types of information, and to extract the strain caused mainly by structural stresses. As an application of the proposed method, the influence of strain deformation and noises. As an application of the proposed method, the influence of strain deformation and noises on the fatigue assessment was investigated based on the separated data. The results show that, the determined values of separatrix frequencies are valuable for the monitoring data from other bridges. The algorithm is a multi resolution and hierarchical method, which has been validated as a simple and effective method for data analyses, and is suitable for the compression and pre-processing of the great amount monitoring data and easy to be integrated in the SHM's (structural health monitoring)software system. The strain due to temperature varying attributes only a little to the errors of fatigue assessment. However, the noises or random disturbance existed in the monitoring data have much responsibility for the errors, the main reason is that the random disturbance shifts the real strain/stress amplitude picked up by real structural stress or strain

    Investigation of metaldehyde removal by powdered activated carbon from different water samples

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    Metaldehyde as a widely used pesticide has been detected in surface water and drinking water in the UK with concentrations higher than the EU and UK standard (0.1 μg L−1). Previous studies have shown that powdered activated carbon (PAC) can adsorb metaldehyde even with the presence of natural organic matter, suggesting a promising solution to the problem. This paper studies the adsorption of metaldehyde onto PAC using different water samples including synthetic water, natural surface water, and water samples taken at different treatment processes from a water treatment plant. Metaldehyde (5 μg L−1) was effectively removed by PAC (50 mg L−1) from all water samples in this study, regardless of the water quality (74.3% to 99.7%). A PAC dosage of 100 mg L−1 was considered appropriate to remove metaldehyde at 5 μg L−1 after the first treatment process of pre-ozone treatment with a maximum adsorption capacity (qm) of 0.25 μg mg−1 given by the data fitted to the Langmuir isotherm model. Removal of metaldehyde by PAC was found to be most effective when PAC was applied after the static flocculation treatment process (98.4%) with a qm of 0.29 μg mg−1. The low adsorption capacity of PAC for low initial concentrations of metaldehyde solution was observed due to the lower driving force for mass transfer in the process of adsorption and competition with water molecules for adsorption sites on PAC

    Relative edge energy in the stability of transition metal nanoclusters of different motifs

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    When a structure is reduced to a nanometer scale, the proportion of the lowly-coordinated edge atoms increases significantly, which can play a crucial role in determining both their geometric and electronic properties, as demonstrated by the recently established generalized Wulff construction principle [S. F. Li, et al., Phys. Rev. Lett., 2013, 111, 115501]. Consequently, it is of great interest to clarify quantitatively the role of the edge atoms that dominate the motifs of these nanostructures. In principle, establishing an effective method valid for determining the absolute value of the surface energy and particularly the edge energy for a given nanostructure is expected to resolve such a problem. However, hitherto, it is difficult to obtain the absolute edge energy of transition metal clusters, particularly when their sizes approach the nanometer regime. In this paper, taking Ru nanoclusters as a prototypical example, our first-principles calculations introduce the concept of relative edge energy (REE), reflecting the net edge atom effect over the surface (facet) atom effect, which is fairly powerful to quasi-quantitatively estimate the critical size at which the crossover occurs between different configurations of a given motif, such as from an icosahedron to an fcc nanocrystal. By contrast, the bulk effect should be re-considered to rationalize the power of the REE in predicting the relative stability of larger nanostructures between different motifs, such as fcc-like and hcp-like nanocrystals

    An Information System Framework and Prototype for Collaborative and Standardized Chinese Liquor Production

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    20th Americas Conference on Information Systems, AMCIS 2014, Savannah, GA, 7-9 August 2014There is a pressing need for Chinese liquor producers to use information systems in managing production process and improving production efficiency for meeting fiercely increasing market competition. Unlike liquor production in other countries, Chinese liquor production replies on experience and manual operations greatly, which has very low-level automation and informatization. This paper takes a famous Chinese liquor producer as the target case company, introduces typical information systems used in Chinese liquor production, explores the motivations to implement information systems, and examines the benefits, the problems encountered as well as the key success factors in implementation and applications of information systems in Chinese liquor production industry.Department of Management and MarketingRefereed conference pape

    SEARCHING FOR DEBRIS DISKS AROUND SEVEN RADIO PULSARS

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    We report on our searches for debris disks around seven relatively nearby radio pulsars, which are isolated sources that were carefully selected as targets on the basis of our deep Ks-band imaging survey. The Ks images obtained with the 6.5m Baade Magellan Telescope at Las Campanas Observatory are analyzed together with the Spitzer/IRAC images at 4.5 and 8.0μm and the WISE images at 3.4, 4.6, 12, and 22μm. No infrared counterparts of these pulsars are found, with flux upper limits of ∼μJy at near-infrared (λ < 10μm) and ∼10–1000μJy at mid-infrared wavelengths (λ > 10 μm). The results of this search are discussed in terms of the efficiency of converting the pulsar spin-down energy to thermal energy and X-ray heating of debris disks, with a comparison made of the two magnetars 4U 0142+61 and 1E 2259+586, which are suggested to harbor a debris disk.published_or_final_versio

    Transmissibility of swing and vertical vibrations in human lower limb

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    2009-2010 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe

    Antiproliferative activity of recombinant human interferon-λ2 expressed in stably transformed BmN cells

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    This study aimed at the generation of a stable transformed silkworm BmN cell line which can continuously express human interferon-λ2 (IFN-λ2) gene, and investigated the antiproliferative activity of this recombinant human IFN-λ2. Silkworm BmN cells were transfected with the recombinant vector pIZT/V5-His harboring the human IFN-λ2 gene. After the BmN cells were transfected with the pIZT/V5- His- hIFN-λ2 vector, the stably transformed BmN cells expressing hIFN-λ2 gene were selected using Zeocin. Following two months of screening, the transformed BmN cell line was obtained. Stable transformed BmN cell line can be maintained at a lower Zeocin concentration. The representing 26 kDa protein band of IFN-λ2 was detected by SDS-PAGE and Western blotting. The expression level of hIFN- λ2, determined by ELISA, was about 8.142 ng in 4 × 105 cells. The antiproliferative activity of hIFN-λ2 was determined by MTT assay. The 50% inhibitory concentrations (IC50) of the recombinant hIFN-λ2 on A549 (lung cancer cells), HL60 (acute promyelocytic leukemia cells), BEL-7402 (liver cancer cells) and M231 cells (breast cancer cells) were approximately 3.21, 2.84, 6.29 and 9.32 ng/ml, respectively. In summary, Human IFN-λ2 can be stably expressed in the transformed BmN cell line, and the expressed recombinant hIFN-λ2 demonstrated antiproliferative activity to tumor cells in vitro.Key words: Human interferon-λ2 protein, gene expression, antiproliferative activity

    Substrate co-doping modulates electronic metal-support interactions and significantly enhances single-atom catalysis

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    Transitional metal nanoparticles or atoms deposited on appropriate substrates can lead to highly economical, efficient, and selective catalysis. One of the greatest challenges is to control the electronic metal–support interactions (EMSI) between the supported metal atoms and the substrate so as to optimize their catalytic performance. Here, from first-principles calculations, we show that an otherwise inactive Pd single adatom on TiO2(110) can be tuned into a highly effective catalyst, e.g. for O2 adsorption and CO oxidation, by purposefully selected metal–nonmetal co-dopant pairs in the substrate. Such an effect is proved here to result unambiguously from a significantly enhanced EMSI. A nearly linear correlation is noted between the strength of the EMSI and the activation of the adsorbed O2 molecule, as well as the energy barrier for CO oxidation. Particularly, the enhanced EMSI shifts the frontier orbital of the deposited Pd atom upward and largely enhances the hybridization and charge transfer between the O2 molecule and the Pd atom. Upon co-doping, the activation barrier for CO oxidation on the Pd monomer is also reduced to a level comparable to that on the Pd dimer which was experimentally reported to be highly efficient for CO oxidation. The present findings provide new insights into the understanding of the EMSI in heterogeneous catalysis and can open new avenues to design and fabricate cost-effective single-atom-sized and/or nanometer-sized catalysts
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