17,869 research outputs found

    Soft Clay Ground Improvement of Ningbo International Airport

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    Ningbo International Airport is built on the soft clay ground first in China. It has a runway 3,000m in length and 45m in width. The thickness of soft clay is greater than 32m. The calculating consolidation settlement is 0. 48m, far beyond to allowable limit. The soft clay ground is improved by wick drain and surcharge precompression. The airport has been put in service since July, 1990. The process and the results of a full scale embankment test, the ground improvement and the settlement observation are described. The influence of the smear and the well resistance of the wick drain on the consolidation rate are discussed

    ACO-RR: Ant Colony Optimization Ridge Regression in Reuse of Smart City System

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    © 2019, Springer Nature Switzerland AG. With the rapid development of artificial intelligence, governments of different countries have been focusing on building smart cities. To build a smart city is a system construction process which not only requires a lot of human and material resources, but also takes a long period of time. Due to the lack of enough human and material resources, it is a key challenge for lots of small and medium-sized cities to develop the intelligent construction, compared with the large cities with abundant resources. Reusing the existing smart city system to assist the intelligent construction of the small and medium-sizes cities is a reasonable way to solve this challenge. Following this idea, we propose a model of Ant Colony Optimization Ridge Regression (ACO-RR), which is a smart city evaluation method based on the ridge regression. The model helps small and medium-sized cities to select and reuse the existing smart city systems according to their personalized characteristics from different successful stories. Furthermore, the proposed model tackles the limitation of ridge parameters’ selection affecting the stability and generalization ability, because the parameters of the traditional ridge regression is manually random selected. To evaluate our model performance, we conduct experiments on real-world smart city data set. The experimental results demonstrate that our model outperforms the baseline methods, such as support vector machine and neural network

    Electrical transport in ion beam created InAs nanospikes

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    Ion beam irradiation has previously been demonstrated as a method for creating nanowire-like semiconductor nanostructures, but no previous studies have reported on the electrical properties of those structures. In this work we describe the creation and in situ transmission electron microscopy electrical characterization of nanoscale InAs spike structures on both InAs and InP substrates fabricated using a focused ion beam erosion method. Those InAs ‘nanospikes’ are found to possess internal structures with varying amounts of ion damaged and single crystalline material. Nanospike electrical behavior is analyzed with respect to model electronic structures and is similar to cases of barrier limited conduction in nanowires. The different electrical responses of each nanospike are found to be the result of variation in their structure, with the conductivity of InAs nanospikes formed on InAs substrates found to increase with the degree of nanospike core crystallinity. The conductivity of InAs nanospikes formed on InP substrates does not show a dependence on core crystallinity, and may be controlled by the other internal barriers to conduction inherent in that system.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/98603/1/0957-4484_23_31_315301.pd

    Investigation to the deep center related properties of low temperature grown InPBi with Hall and photoluminescence

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    InP1-xBix epilayers with bismuth (Bi) concentration x= 1.0% were grown on InP by gas source molecular beam epitaxy (GS-MBE) at low temperature (LT). Bi incorporation decreased the intrinsic free electron concentration of low temperature grown InP indicated by hall analysis. It is concluded that deep level center was introduced by Bi. Influence of Si doping on the InP1-xBix films Photoluminescence (PL) was investigated. N-type doping in the InP1-xBix epilayers was found to be effective at PL enhancement. Blue shift of InPBi PL emission wavelength was observed as the Si doping concentration increasing. Two independent peaks were fitted and their temperature dependence behavior was observed to be distinct obviously. Two individual radiative recombination processes were expected to be involved

    Nernst Effect and Superconducting Fluctuations in Zn-doped YBa2_{2}Cu3_{3}O7δ_{7-\delta}

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    We report the measurements of in-plane resistivity, Hall effect, and Nernst effect in Zn doped YBa2_{2}Cu3_{3}O7δ_{7-\delta} epitaxial thin films grown by pulsed laser deposition technique. The pseudogap temperature, TT^*, determined from the temperature dependence of resistivity, does not change significantly with Zn doping. Meanwhile the onset temperature (TνT^{\nu}) of anomalous Nernst signal above Tc0T_{c0}, which is interpreted as evidence for vortex-like excitations, decreases sharply as the superconducting transition temperature Tc0T_{c0} does. A significant decrease in the maximum of vortex Nernst signal in mixed state is also observed, which is consistent with the scenario that Zn impurities cause a decrease in the superfluid density and therefore suppress the superconductivity. The phase diagram of TT^*, TνT^{\nu}, and Tc0T_{c0} versus Zn content is presented and discussed.Comment: 6 pages, 5 figures, Latex; v2: to be published in PR
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