20 research outputs found

    Research on dedicated rail power supply system for electric cars

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    in order to improve the endurance capacity and driving safety of electric vehicles, a special track power supply system for electric cars on expressways is studied. The working principle of the main components of the system, such as sliding contact charging track and mechanical charging arm, is simulated and analyzed by using SolidWorks software. The results show that the charging function of the contact track can provide unlimited endurance for electric vehicles, and the guidance function of the track can also ensure the safety of highspeed driving

    Sm3+-Mn4+ activated Sr2GdTaO6 red phosphor for plant growth lighting and optical temperature sensing

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    Optical temperature sensing and plant growth lighting multifunctional applications can be realized by red luminescent materials. In this paper, novel Sm3+ and Sm3+-Mn4+ activated Sr2GdTaO6 (SGTO) red phosphors for plant growth and optical temperature sensing were comprehensively analyzed. The phase, luminescence property and thermal stability of the material were tested. For PL performance, SGTO:0.075Sm3+ exhibits the maximum emission intensity in the range (560–670 nm). The emission range of SGTO:0.075Sm3+ after introducing Mn4+ is mainly dark red light emission in the range from 630 to 750 nm, and the optimum dopingconcentration of Mn4+ is determined to be 0.3 %. The emission band of SGTO:0.075Sm3+ and SGTO:0.075Sm3+, 0.003Mn4+ matches the absorption band of the plants. For optical temperature sensing properties, the relative sensitivity (Sr) and absolute sensitivity (Sa) of SGTO:0.075Sm3+, 0.003Mn4+ are 2.94

    Preliminary study on the utilization of Ca2+ and HCO3 − in karst water by different sources of Chlorella vulgaris

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    This article aims to present a picture of how a university discipline has been created in Lithuania, given the background of changes caused by the Lithuania’s emancipation from the Soviet Union. The theoretical frame of reference is provided by a modified model of Bronfenbrenners developmental ecology. Data collection has primarily been in the form of interviews with university staff from Lithuanian institutions for higher education. In addition to the interviews, literature lists, course schedules and other key documents have been collected and analysed. The analysis focuses on individual’s conceptualisation of three main areas. The study demonstrates how the creation of management and economics as a university discipline in Lithuania has been formed by a combination of political/ideological, economic, institutional and individual factors. One of the study’s main contributions is to highlight the significance of the concept of academic freedom and to focus on the paradox, where constraint under the old system is replaced by another form of constraint. In this case, where the rigidity of the old Soviet doctrine is replaced by a new freedom; but instead of being given greater opportunities to influence and change the subject, the academic staff are forced into a position where, once again they are subjugated to the influences of international sources

    Interplanetary scintillation observation and space weather modelling

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    Interplanetary scintillation (IPS) refers to random fluctuations in radio intensity of distant small-diameter celestial object, over time periods of the order of 1 s. The scattering and scintillation of emergent radio waves are ascribed to turbulent density irregularities transported by the ubiquitous solar wind streams. The spatial correlation length of density irregularities and the Fresnel radius of radio diffraction are two key parameters in determining the scintillation pattern. Such a scintillation pattern can be measured and correlated between multi-station radio telescopes on the Earth. Using the “phase-changing screen” scenario based on the Born approximation, the bulk-flow speed and turbulent spectrum of the solar wind streams can be extracted from the single-station power spectra fitting and the multi-station cross-correlation analysis. Moreover, a numerical computer-assisted tomography (CAT) model, iteratively fit to a large number of IPS measurements over one Carrington rotation, can be used to reconstruct the global velocity and density structures in the inner heliosphere for the purpose of space weather modelling and prediction. In this review, we interpret the underlying physics governing the IPS phenomenon caused by the solar wind turbulence, describe the power spectrum and cross correlation of IPS signals, highlight the space weather application of IPS-CAT models, and emphasize the significant benefits from international cooperation within the Worldwide IPS Stations (WIPSS) network

    An Effective Self-Attention-Based Hybrid Model for Short-Term Traffic Flow Prediction

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    Vehicle exhaust is one of the main sources of carbon emissions. The short-term traffic flow prediction plays an important role in alleviating traffic congestion, optimizing the travel structure, and reducing traffic carbon emissions. The current advanced models of short-term traffic flow prediction are evaluated in this work, especially their inadequacies. To improve the prediction accuracy and ensure fine traffic management, an effective self-attention-based hybrid model is proposed to predict the short-term traffic flow. The proposed model includes an encoder-decoder neural network module and a self-attention mechanism module. The self-attention mechanism module is applied as a feature extraction unit in this hybrid model to enhance the ability of key information capture and to settle the problem on key information disappearing due to the increasing sequence length in traditional models. The dataset of the Guangdong freeway toll station is used for the experimental testing. Compared with several baseline models, the proposed model is more suitable for real-time prediction and can provide highly accurate results. Also, a better interpretability is presented in this proposed model. The experimental results showed that MAE, RMSE, and MAPE of the proposed model are 3.01, 4.38, and 12.99%, respectively. Our new hybrid model gives a higher accuracy than the support vector regression (SVR) model, LSTM neural network-attention (LSTM-attention) model, and temporal convolutional network (TCN) model. It shows that the proposed model in this work is favorable to the short-term traffic flow prediction

    Copper isotopes trace the evolution of skarn ores: a case study from the Hongshan-Hongniu Cu deposit, southwest China

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    Transition metal isotopes are sensitive geochemical tracers of ore genesis. Here we present MC-ICP-MS analytical data of Cu isotope compositions from the Hongshan-Hongniu Cu deposit in Yunnan province. The ή 65 Cu values (ή 65 Cu = [( 65 Cu/ 63 Cu) sample /( 65 Cu/ 63 Cu) NIST976  − 1] × 1000) of seven whole-rock quartz monzonite porphyries and twenty-two chalcopyrite samples from the skarn ore-bodies display relatively narrow ranges from −0.15‰ to 0.38‰ and from −0.02‰ to 0.77‰, respectively. The overlap of ή 65 Cu values indicates a genetic relationship between the quartz monzonite porphyry and skarn ore-bodies. We also evaluate the spatial and temporal variations of Cu isotope compositions in the skarn ore-bodies by comparison with some well-documented porphyry deposits in the world. The quartz monzonite porphyry shows compositional zoning with the inner domain enriched in heavy Cu isotope and the skarn related to the porphyry depleted in heavy Cu isotope. The chalcopyrites that formed during the late stage of mineralization tend to be enriched in heavy Cu isotope, and this feature is analogous to porphyry deposits. The ή 65 Cu values of the quartz monzonite porphyry show typical features of hypogene mineralization, suggesting a potential scope for deep exploration and development in this deposit
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