1,375 research outputs found
Research Progress of the International Carbon Tariff: A Review
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
Nodeless superconductivity in the presence of spin-density wave in pnictide superconductors: The case of BaFeNiAs
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 BaFeNiAs 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 = 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 -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
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)
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)
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)
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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