4,079 research outputs found

    Evaluating A Self-access Centre’s Effectiveness And efficiency: A Case Study And Reflection

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    This article discusses changes that occurred after a case study that examined the effectiveness and efficiency of a Self-access Centre (SAC) within a university in Hong Kong using Morrison's (2003) Evaluation of Self-access Language Learning Centre framework. The case study addressed issues from a stakeholder’s perspective by collecting data from learners through an online questionnaire and conducting 15 semi-structured interviews, an advisers' focus group and management interviews and reports. The outcome of the study showed that a wider perspective for senior managers and insights for evaluation of the support services is vital to making key decisions in context. Upon reflection of the findings with the new SAC manager, more acute decision-making and continuous improvement is needed to enhance effectiveness and efficiency of the running of the SAC. To achieve this, regular feedback from various stakeholders, also re-structuring human and non-human support systems is vital.published_or_final_versio

    Understanding coastal urban and peri‐urban indigenous people’s vulnerability and adaptive capacity to climate change

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    This brief presentation will commence to address a number of emerging questions that are underpinned by the current NCCARF research project: Understanding Urban and Peri‐urban Indigenous People’s vulnerability and adaptive capacity to Climate Change. In terms of climate change adaptation barriers, options and priorities, what are the major considerations for indigenous communities residing in coastal peri-urban and urban places that may differ from those of their non-indigenous counterparts and possibly from Indigenous communities living away from the coasts? It will speculate on whether these considerations can be addressed through existing planning and management frameworks

    Evolutionary Subnetworks in Complex Systems

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    Links in a practical network may have different functions, which makes the original network a combination of some functional subnetworks. Here, by a model of coupled oscillators, we investigate how such functional subnetworks are evolved and developed according to the network structure and dynamics. In particular, we study the case of evolutionary clustered networks in which the function of each link (either attractive or repulsive coupling) is updated by the local dynamics. It is found that, during the process of system evolution, the network is gradually stabilized into a particular form in which the attractive (repulsive) subnetwork consists only the intralinks (interlinks). Based on the properties of subnetwork evolution, we also propose a new algorithm for network partition which is distinguished by the convenient operation and fast computing speed.Comment: 4 pages, 4 figure

    Pseudo-gap features of intrinsic tunneling in (HgBr_2)-Bi2212 single crystals

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    The c-axis tunneling properties of both pristine Bi2212 and its HgBr2_2 intercalate have been measured in the temperature range 4.2 - 250 K. Lithographically patterned 7-10 unit-cell heigh mesa structures on the surfaces of these single crystals were investigated. Clear SIS-like tunneling curves for current applied in the c\it c-axis direction have been observed. The dynamic conductance dI/I/dV(V)V(V) shows both sharp peaks corresponding to a superconducting gap edge and a dip feature beyond the gap, followed by a wide maximum, which persists up to a room temperature. Shape of the temperature dependence of the {\it c}-axis resistance does not change after the intercalation suggesting that a coupling between CuO2\rm CuO_2-bilayers has little effect on the pseudogap.Comment: 6 pages, 5 figures; presented at the Second Int Conf. New3Sc-1999 (Las Vegas, NV

    Novel Nanostructured SiO2/ZrO2 Based Electrodes with Enhanced Electrochemical Performance for Lithium-ion Batteries

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    In this article, a novel anode material with high electrochemical performance, made of elements abundant on the Earth, is reported for use in lithium ion batteries. A chemically synthesised material (SiO2/ZrO2) containing Si-O-Zr bonds, exhibits as much as 2.1 times better electrochemical performance at the 10th cycle than a physically mixed material (SiO2 + ZrO2) of the same elements. When compared to synthesized SiO2 or conventional graphite-based electrodes, the SiO2/ZrO2 anode shows superior capability and cycling performance. This superior performance is ascribed to the effect of ternary compounds, which contributes not only to increasing the packing density, but also to creating the Si-O-Zr bond that makes additional reactions between SiO2/ZrO2 and lithium ions possible. The Si-O-Zr bond also contributes to improved conductivity for SSZ and provides facile paths for charge transfer at the electrode/electrolyte interface. Therefore, the overall internal resistance in a battery would be decreased and better performance could thus be obtained, with this type of anode. In every result, the positive influence of the Si-O-Zr bonds in the anode of a lithium ion battery was confirmed

    Vibration signature analysis of multistage gear transmission

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    An analysis is presented for multistage multimesh gear transmission systems. The analysis predicts the overall system dynamics and the transmissibility to the gear box or the enclosed structure. The modal synthesis approach of the analysis treats the uncoupled lateral/torsional model characteristics of each stage or component independently. The vibration signature analysis evaluates the global dynamics coupling in the system. The method synthesizes the interaction of each modal component or stage with the nonlinear gear mesh dynamics and the modal support geometry characteristics. The analysis simulates transient and steady state vibration events to determine the resulting torque variations, speeds, changes, rotor imbalances, and support gear box motion excitations. A vibration signature analysis examines the overall dynamic characteristics of the system, and the individual model component responses. The gear box vibration analysis also examines the spectral characteristics of the support system

    Low-energy excitations of the one-dimensional half-filled SU(4) Hubbard model with an attractive on-site interaction: Density-matrix renormalization-group calculations and perturbation theory

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    We investigate low-energy excitations of the one-dimensional half-filled SU(4) Hubbard model with an attractive on-site interaction U < 0 using the density matrix renormalization group method as well as a perturbation theory. We find that the ground state is a charge density wave state with a long range order. The ground state is completely incompressible since all the excitations are gapful. The charge gap which is the same as the four-particle excitation gap is a non-monotonic function of U, while the spin gap and others increase with increasing |U| and have linear asymptotic behaviors.Comment: 4 pages, 3 figures, submitte

    China\u27s Media: The Impact of the Internet

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    [T]his paper provides a review of how the use of the Internet has grown and been regulated in China. We then draw some conclusions on what the experience to date may have to tell us about future regulatory and usage patterns with respect to the Internet in China

    From the surface to the seafloor: How giant larvaceans transport microplastics into the deep sea.

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    Plastic waste is a pervasive feature of marine environments, yet little is empirically known about the biological and physical processes that transport plastics through marine ecosystems. To address this need, we conducted in situ feeding studies of microplastic particles (10 to 600 μm in diameter) with the giant larvacean Bathochordaeus stygius. Larvaceans are abundant components of global zooplankton assemblages, regularly build mucus "houses" to filter particulate matter from the surrounding water, and later abandon these structures when clogged. By conducting in situ feeding experiments with remotely operated vehicles, we show that giant larvaceans are able to filter a range of microplastic particles from the water column, ingest, and then package microplastics into their fecal pellets. Microplastics also readily affix to their houses, which have been shown to sink quickly to the seafloor and deliver pulses of carbon to benthic ecosystems. Thus, giant larvaceans can contribute to the vertical flux of microplastics through the rapid sinking of fecal pellets and discarded houses. Larvaceans, and potentially other abundant pelagic filter feeders, may thus comprise a novel biological transport mechanism delivering microplastics from surface waters, through the water column, and to the seafloor. Our findings necessitate the development of tools and sampling methodologies to quantify concentrations and identify environmental microplastics throughout the water column

    The Van der Waals interaction of the hydrogen molecule - an exact local energy density functional

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    We verify that the van der Waals interaction and hence all dispersion interactions for the hydrogen molecule given by: W"= -{A/R^6}-{B/R^8}-{C/R^10}- ..., in which R is the internuclear separation, are exactly soluble. The constants A=6.4990267..., B=124.3990835 ... and C=1135.2140398... (in Hartree units) first obtained approximately by Pauling and Beach (PB) [1] using a linear variational method, can be shown to be obtainable to any desired accuracy via our exact solution. In addition we shall show that a local energy density functional can be obtained, whose variational solution rederives the exact solution for this problem. This demonstrates explicitly that a static local density functional theory exists for this system. We conclude with remarks about generalising the method to other hydrogenic systems and also to helium.Comment: 11 pages, 13 figures and 28 reference
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