298 research outputs found

    Durability of Composite-Modified Asphalt Mixture Based on Inherent and Improved Performance

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    The composite performance of modified asphalt and composite-modified asphalt mixture (CMAM) is divided into inherent performance and improved performance. The inherent performance refers to the original performance of the virgin asphalt and asphalt mixture. The improved performance refers to the performance obtained by modifying the virgin asphalt. In the study, the modified asphalt and asphalt mixture were tested through a series of experiments. The antiaging durability of the modified asphalt is explored based on the inherent performance and improved performance at high and low temperatures. The antiaging durability of the modified asphalt mixture is explored based on the inherent performance and improved performance at the mechanical performance. Meanwhile, based on inherent and improved performances, this chapter uses three kinds of CMAM (4% SBS/3% SBR, 4% SBS/15% rubber, and 4% SBR/15% rubber) as research objects to test the change rule of mechanical properties. This chapter outlines CMAM design, mechanical property tests, and comparative durability analysis

    Enabling Work-conserving Bandwidth Guarantees for Multi-tenant Datacenters via Dynamic Tenant-Queue Binding

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    Today's cloud networks are shared among many tenants. Bandwidth guarantees and work conservation are two key properties to ensure predictable performance for tenant applications and high network utilization for providers. Despite significant efforts, very little prior work can really achieve both properties simultaneously even some of them claimed so. In this paper, we present QShare, an in-network based solution to achieve bandwidth guarantees and work conservation simultaneously. QShare leverages weighted fair queuing on commodity switches to slice network bandwidth for tenants, and solves the challenge of queue scarcity through balanced tenant placement and dynamic tenant-queue binding. QShare is readily implementable with existing switching chips. We have implemented a QShare prototype and evaluated it via both testbed experiments and simulations. Our results show that QShare ensures bandwidth guarantees while driving network utilization to over 91% even under unpredictable traffic demands.Comment: The initial work is published in IEEE INFOCOM 201

    Luminescence of delafossite-type CuAlO2 fibers with Eu substitution for Al cations

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    CuAlO2 has been examined as a potential luminescent material by substituting Eu for Al cations in the delafossite structure. CuAlO2:Eu3+ nanofibers have been prepared via electrospinning for the ease of mitigating synthesis requirements and for future optoelectronics and emerging applications. Single-phase CuAlO2 fibers could be obtained at a temperature of 1100 °C in air. The Eu was successfully doped in the delafossite structure and two strong emission bands at ~405 and 610 nm were observed in the photoluminescence spectra. These bands are due to the intrinsic near-band-edge transition of CuAlO2 and the f-f transition of the Eu3+ activator, respectively. Further electrical characterization indicated that these fibers exhibit semiconducting behavior and the introduction of Eu could act as band-edge modifiers, thus changing the thermal activation energies. In light of this study, CuAlO2:Eu3+ fibers with both strong photoluminescence and p-type conductivity could be produced by tailoring the rare earth doping concentrations

    Forecasting the BAO Measurements of the CSST galaxy and AGN Spectroscopic Surveys

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    The spectroscopic survey of the China Space Station Telescope (CSST) is expected to obtain a huge number of slitless spectra, including more than one hundred million galaxy spectra and millions of active galactic nuclei (AGN) spectra. By making use of these spectra, we can measure the Baryon Acoustic Oscillation (BAO) signals over large redshift ranges with excellent precisions. In this work, we predict the CSST measurements of the post-reconstruction galaxy power spectra at 0<z<1.2 and pre-reconstruction AGN power spectra at 0<z<4, and derive the BAO signals at different redshift bins by constraining the BAO scaling parameters using the Markov Chain Monte Carlo method. Our result shows that the CSST spectroscopic survey can provide accurate BAO measurements with precisions higher than 1% and 3% for the galaxy and AGN surveys, respectively. By comparing with current measurements in the same range at low redshifts, this can improve the precisions by a factor of 2∼32\sim3, and similar precisions can be obtained in the pessimistic case. We also investigate the constraints on the cosmological parameters using the measured BAO data by the CSST, and obtain stringent constraint results for the energy density of dark matter, Hubble constant, and equation of state of dark energy.Comment: 15 pages, 9 figures, 4 table

    Cosmological Constraint Precision of the Photometric and Spectroscopic Multi-probe Surveys of China Space Station Telescope (CSST)

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    As one of Stage IV space-based telescopes, China Space Station Telescope (CSST) can perform photometric and spectroscopic surveys simultaneously to efficiently explore the Universe in extreme precision. In this work, we investigate several powerful CSST cosmological probes, including cosmic shear, galaxy-galaxy lensing, photometric and spectroscopic galaxy clustering, and number counts of galaxy clusters, and study the capability of these probes by forecasting the results of joint constraints on the cosmological parameters. By referring to real observational results, we generate mock data and estimate the measured errors based on CSST observational and instrumental designs. To study the systematical effects on the results, we also consider a number of systematics in CSST photometric and spectroscopic surveys, such as the intrinsic alignment, shear calibration uncertainties, photometric redshift uncertainties, galaxy bias, non-linear effects, instrumental effects, etc. The Fisher matrix method is used to derive the constraint results from individual or joint surveys on the cosmological and systematical parameters. We find that the joint constraints by including all these CSST cosmological probes can significantly improve the results from current observations by one order of magnitude at least, which gives Ωm\Omega_m and σ8\sigma_8 <<1% accuracy, and w0w_0 and waw_a <<5% and 20% accuracies, respectively. This indicates that the CSST photometric and spectroscopic multi-probe surveys could provide powerful tools to explore the Universe and greatly improve the studies of relevant cosmological problems.Comment: 17 pages, 12 figures, 3 tables. Accepted for publication in MNRA

    Advances in Acute Myeloid Leukemia Stem Cells

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    As a common hematological malignant tumor, acute leukemia is believed to originate from a subpopulation of special cancer cells, named cancer stem cells. Cancer stem cells are recognized to be the main source of tumor origin, multidrug resistance, metastasis, and recurrence. Leukemic stem cells (LSCs) were first identified and confirmed to play an important role in the occurrence and development of leukemia. In this article, we summarize the following content: special markers and sorting methods for acute myeloid leukemia stem cells and the role of cancer stem cells in treatment resistance, metastasis and invasion, recurrence, and target treatment of acute leukemia

    Queuing Game Theory Based Optimal Routing Scheme for Heterogeneous Users over Space Information Networks

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    An optimal routing scheme in space information networks was presented to balance network loads for heterogeneous users. According to the competition among the nodes, the model was built based on queuing game theory. The virtual routing platform was in charge of resources allocation and route selection. It got user’s gain to decide which node the user joined in. Owning to the existing of heterogeneous users, an optimal admission fee needed to be obtained to avoid congestion. In our model, firstly, the whole welfare of the system was formulated. Then the optimal admission fee was calculated through maximizing the whole welfare. Meanwhile, the average maximum queue length was generated to set the buffer space of the node. At last, a routing factor was introduced into the route algorithm in order that the optimal routing could be selected by heterogeneous users. As a result, the system welfare reaches the maximum

    APPROACH TO ADJUSTING LAMPS’ HEIGHTS AND ANGLES: DESIGN AND IMPLEMENTATION OF AN ELEVATING DEVICE FOR ILLUMINATION IN SLEDGE TESTS

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    In order to achieve the aim of adjusting heights and angles of lamps in sledge tests, detailed requirements were analyzed, and the implementation scheme was devised. The prototype of the elevating device was designed to validate the effect. Both the power circuit and the control circuit were researched on to power and control the 4 3-phase asynchronous motors respectively. An effective solution was provided to the adjustment of the essential parameters in sledge tests’ illumination. Manual control and remote control modes were both designed and employed to make the necessary adjustments possible. On-site application validated that the elevating device was effective and could be used to adjust parameters relevant with lamps’ spatial positions
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