1,375 research outputs found

    Research Progress of the International Carbon Tariff: A Review

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    Under the constraints of the target peak carbon dioxide emissions and carbon neutrality, how the international carbon tariff can be levied have become an important question for scholars and research institutions all over the world. This paper aimed to comprehensively sort the relevant literature on the Carbon Border Adjustment Mechanism from an economic perspective. Based on defining the concept connotation and extension of carbon tariff, we summarized and determined the price mechanism, institutional mechanism, and coordination mechanism of the carbon tariff, and analyzed the impact of carbon tariff on the economic environment and other fields. Further, this paper makes an international comparison of the existing reasonably operable carbon tariff, points out the focus and direction of the next research, and strives to provide valuable experience and theoretical reference for the innovative practice of building the international Carbon Border Adjustment Mechanism. Keywords: carbon tariff, border tax adjustment, connotation and extension, mechanism design, economic impac

    HisRect:Features from Historical Visits and Recent Tweet for Co-Location Judgement

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    Nodeless superconductivity in the presence of spin-density wave in pnictide superconductors: The case of BaFe2x_{2-x}Nix_{x}As2_{2}

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    The characteristics of Fe-based superconductors are manifested in their electronic, magnetic properties, and pairing symmetry of the Cooper pair, but the latter remain to be explored. Usually in these materials, superconductivity coexists and competes with magnetic order, giving unconventional pairing mechanisms. We report on the results of the bulk magnetization measurements in the superconducting state and the low-temperature specific heat down to 0.4 K for BaFe2x_{2-x}Nix_{x}As2_{2} single crystals. The {electronic} specific heat displays a pronounced anomaly at the superconducting transition temperature and a small residual part {at low temperatures in the superconducting state}. The normal-state Sommerfeld coefficient increases with Ni doping for xx = 0.092, 0.096, and 0.10, which illustrates the competition between magnetism and superconductivity. Our analysis of the temperature dependence of the superconducting-state specific heat and the London penetration depth provides strong evidence for a two-band ss-wave order parameter. Further, the data of the London penetration depth calculated from the lower critical field follow an exponential temperature dependence, characteristic of a fully gapped superconductor. These observations clearly show that the superconducting gap in the nearly optimally doped compounds is nodeless.Comment: 11 pages, 5 figure

    Interaction of a symmetrical α,α',δ,δ'-Tetramethyl-cucurbit[6]uril with Ln³⁺ : potential applications for isolation of lanthanides

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    The interaction of a symmetrical α,α′,δ,δ′-tetramethyl-cucurbit[6]uril (TMeQ[6]) with a series of lanthanide cations (Ln³⁺) was investigated in neutral water and in acidic solution. Analysis by single crystal X-ray diffraction revealed that different isomorphous families formed under different synthetic conditions. Such differences in the interaction between TMeQ[6] and Ln³⁺ could potentially be used for isolating heavier Ln³⁺ from their lighter counterparts in neutral solution, and lighter lanthanide cations from their heavier counterparts in acidic solution

    Optimization of terrestrial ecosystem model parameters using atmospheric CO2 concentration data with the Global Carbon Assimilation System (GCAS)

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    Author Posting. © American Geophysical Union, 2017. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Journal of Geophysical Research: Biogeosciences 122 (2017): 3218–3237, doi:10.1002/2016JG003716.The Global Carbon Assimilation System that assimilates ground-based atmospheric CO2 data is used to estimate several key parameters in a terrestrial ecosystem model for the purpose of improving carbon cycle simulation. The optimized parameters are the leaf maximum carboxylation rate at 25°C (V25 max), the temperature sensitivity of ecosystem respiration (Q10), and the soil carbon pool size. The optimization is performed at the global scale at 1° resolution for the period from 2002 to 2008. The results indicate that vegetation from tropical zones has lower V25 max values than vegetation in temperate regions. Relatively high values of Q10 are derived over high/midlatitude regions. Both V25 max and Q10 exhibit pronounced seasonal variations at middle-high latitudes. The maxima in V25 max occur during growing seasons, while the minima appear during nongrowing seasons. Q10 values decrease with increasing temperature. The seasonal variabilities of V25 max and Q10 are larger at higher latitudes. Optimized V25 max and Q10 show little seasonal variabilities at tropical regions. The seasonal variabilities of V25 max are consistent with the variabilities of LAI for evergreen conifers and broadleaf evergreen forests. Variations in leaf nitrogen and leaf chlorophyll contents may partly explain the variations in V25 max. The spatial distribution of the total soil carbon pool size after optimization is compared favorably with the gridded Global Soil Data Set for Earth System. The results also suggest that atmospheric CO2 data are a source of information that can be tapped to gain spatially and temporally meaningful information for key ecosystem parameters that are representative at the regional and global scales.National Key R&D Program of China Grant Number: 2016YFA0600204; National Natural Science Foundation of China Grant Number: 415713382018-06-2

    Vremenski razlučeni fotoluminescentni spektri legure (AlxGa1−x)0.51In0.49P (x = 0.29)

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    Measurements of time-resolved photoluminescence (TRPL) spectra were made in a study of the optical properties of partially ordered quaternary (AlxGa1-x)0.51In0.49P (x=0.29) alloy. Both excitation-wavelength dependence of lifetime and excitation-intensity dependence of lifetime show a wide distribution of carriers. In TRPL spectra measured at 300 K, a blue-shift of photoluminescence (PL) peaks in (AlxGa1-x)0.51In0.49P is observed. The phenomenon is in agreement with the Z-shaped temperature dependence of the PL peak. Possible origins of the blue-shift and Z-shaped behaviour of PL peak are presented.Načinili smo vremenski-razlučena (VR) mjerenja fotoluminescentnih (FL) spektara radi istraživanja optičkih svojstava djelomično sređene četverokomponentne legure (AlxGa1−x)0.51In0.49P (x = 0.29). Obje ovisnosti vremena života, uzbuda – valna duljina i uzbuda – intenzitet pokazuju široku raspodjelu nositelja. VR FL spektri (AlxGa1−x)0.51In0.49P na 300 K pokazuju plavi pomak fotoluminescentnih linija. Ta je pojava u skladu s temperaturnom ovisnošću FL vrha u vidu slova Z. Raspravljaju se mogući uzroci plavog pomaka i Z-ovisnosti FL vrha

    Vremenski razlučeni fotoluminescentni spektri legure (AlxGa1−x)0.51In0.49P (x = 0.29)

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    Measurements of time-resolved photoluminescence (TRPL) spectra were made in a study of the optical properties of partially ordered quaternary (AlxGa1-x)0.51In0.49P (x=0.29) alloy. Both excitation-wavelength dependence of lifetime and excitation-intensity dependence of lifetime show a wide distribution of carriers. In TRPL spectra measured at 300 K, a blue-shift of photoluminescence (PL) peaks in (AlxGa1-x)0.51In0.49P is observed. The phenomenon is in agreement with the Z-shaped temperature dependence of the PL peak. Possible origins of the blue-shift and Z-shaped behaviour of PL peak are presented.Načinili smo vremenski-razlučena (VR) mjerenja fotoluminescentnih (FL) spektara radi istraživanja optičkih svojstava djelomično sređene četverokomponentne legure (AlxGa1−x)0.51In0.49P (x = 0.29). Obje ovisnosti vremena života, uzbuda – valna duljina i uzbuda – intenzitet pokazuju široku raspodjelu nositelja. VR FL spektri (AlxGa1−x)0.51In0.49P na 300 K pokazuju plavi pomak fotoluminescentnih linija. Ta je pojava u skladu s temperaturnom ovisnošću FL vrha u vidu slova Z. Raspravljaju se mogući uzroci plavog pomaka i Z-ovisnosti FL vrha
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