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We present the gluon distribution functions of the pion and kaon in small-x and large-x regions, and compare them with the results obtained from lattice QCD and continuum Schwinger function methods. Whether in the small-x region or the large-x region, our gluon distribution of the pion is consistent with the results of lattice QCD and continuum Schwinger function methods. We also calculate the first four moments of gluon distributions of the pion and kaon at different Q 2 scales. In addition, we present the mass decomposition of the pion and kaon with the dynamical parton distribution functions calculated by the DGLAP equation with parton–parton recombination corrections. The mass structures of the pion and kaon are completely different from that of the proton. [ABSTRACT FROM AUTHOR]

The interaction of vector meson with nucleon, vector meson-nucleon scattering length | α VN | , is an important component of the study of hadronic interactions. Nowadays many scattering length values have been reported using the recent photoproduction experiment data or quasidata. In addition, the study of trace anomalous energy contribution to the proton mass is also a hot topic in non-perturbative QCD and hadron physics. In this work, we established the relationship between the scattering length of the vector meson-proton | α Vp | and the trace anomaly contribution of the proton mass T A . With the scattering length values extracted by using the Vector Meson Dominance model, we obtained the trace anomaly contribution of the proton mass T A = (19.0 % ± 0.8 % ), which is of similar order of magnitude as the 23 % given by Lattice QCD calculation. [ABSTRACT FROM AUTHOR]

In this study, we try to extract the mass radii of the neutron and the proton from the differential cross section data of near-threshold ω and ϕ photoproductions on deuterium target, which is often approximated as a quasi-free neutron plus a quasi-free proton. The incoherent data of ω and ϕ photoproductions are provided by CBELSA/TAPS collaboration and LEPS collaboration respectively, where the deuteron is disintegrated in the experiments to measure the properties of individual nucleons. Under the VMD model and the assumption of dipole gravitational form factor, we determined the loosely bound neutron and proton mass radii to be 0.795 ± 0.092 (s t a t.) ± 0.073 (s y s t.) fm and 0.744 ± 0.029 (s t a t.) ± 0.042 (s y s t.) fm respectively from the near-threshold data of γ d → ω n (p) and γ d → ω p (n) , for the first time. With the near-threshold and incoherent ϕ photoproduction data of γ d → ϕ p n , we determined the average mass radius of the bound nucleon (neutron or proton) inside the deuteron to be 0.755 ± 0.039 (s t a t.) ± 0.039 (s y s t.) fm, for the first time. For a comparison study, we also extracted the mass radius of the free proton from the ω photoproduction on the hydrogen target by CBELSA/TAPS collaboration. Based on our analysis results under the assumptions of VMD model and a low energy QCD theorem, we find that the neutron mass radius is consistent with the proton mass radius within the current statistical uncertainties, and that the nuclear modification on the nucleon mass radius is small inside the deuteron. [ABSTRACT FROM AUTHOR]

[Display omitted] • V-Ni@NiMoO 4 /Ni 12 P 5 with a microsphere structure as the supporting framework exhibits excellent cycling stability. • For OER, a low overpotential of only 254 mV is required to achieve a current density of 50 mA cm, with no significant decline observed after 114 h of cycling. • The introduction of phosphorus enhances the electron transfer at the Ni active sites, better activating adsorbates, and thus improving catalytic performance. At present, there are few reports on the micron-sized catalysts for overall water splitting. In this study, phosphating method were used to construct the self-supporting catalyst (V doped Ni microspheres coated by NiMoO 4 /Ni 12 P 5) with microspherical structure, providing a short path and a stable structure to guarantee quick electron transfer and excellent catalytic performance. Hence, oxygen evolution reaction (OER) only needs 254 mV to reach a current density of 50 mA cm−2 in 1.0 mol/L KOH, after 114 h without attenuation. The catalyst can achieve a current densitiy of 10 mA cm−2 with a voltage of only 158 mV for hydrogen evolution reaction (HER). When micron scale V-Ni@NiMoO 4 /Ni 12 P 5 is used as both anode and cathode for overall water splitting, the device can operate at a current density of 10 mA cm−2 for more than 200 h of good stability. Its superior catalytic performance can be attributed to the construction of micron size and phosphating. DFT calculations indicate that the introduction of P better activates the adsorbed *OH and H 2 O*, reduces reaction the energy barrier, and improves the catalytic activity. [ABSTRACT FROM AUTHOR]

We present pion and kaon parton distribution functions from a global QCD analysis of the experimental data within the framework of dynamical parton model. We use the DGLAP equations with parton–parton recombination corrections and the valence input of uniform distribution which maximizes the information entropy. At our input scale Q 0 2 , there are no sea quark and gluon distributions. All the sea quarks and gluons of the pion and the kaon are completely generated from the parton splitting processes. The mass-dependent parton splitting kernel is applied for the strange quark distribution in the kaon. The obtained valence quark and sea quark distributions at high Q 2 ( Q 2 > 5 GeV 2 ) are compatible with the existed experimental measurements. Furthermore, the asymptotic behaviours of parton distribution functions at small and large x have been studied for both the pion and the kaon. Lastly, the first three moments of parton distributions at high Q 2 scale are calculated, which are consistent with other theoretical predictions. [ABSTRACT FROM AUTHOR]

We calculate the valence quark distribution functions of the π meson using the non-relativistic chiral constituent quark model. The π wave function is obtained by solving the two-body Schrödinger equation within the framework of constituent quark model. We transform the π wave function from the rest frame to the light cone or infinite momentum frame based on the Lorentz boost. The valence quark distributions at the initial evolution scale are obtained. The QCD evolution is given with the DGLAP equations with parton-parton recombination corrections. With tuning the valence up (down) quark mass to 70 MeV, the calculated valence up quark distributions at Q 2 = 20 GeV2 are in good agreement with the E615 experimental data. The structure functions F 2 π (x , Q 2) of pion are also calculated which consist with the H1 experimental data. The proposed mechanisms here could be also used to study other hadrons. [ABSTRACT FROM AUTHOR]

We present the polarized parton distribution functions from a QCD analysis of the worldwide polarized deep inelastic scattering data, based on the dynamical parton distribution model. All the sea quarks and gluons are dynamically generated from QCD radiations, with the nonperturbative input comprising only the polarized valence quark distributions. This approach leads to a simple parametrization, which has only seven free parameters. In the analysis, we apply the DGLAP equations with parton-parton recombination corrections. For the first step, the DGLAP equations, parton-parton recombination corrections, and experimental observable g 1 are all evaluated at the leading order. The parameterized nonperturbative input at an extremely low Q 0 2 reproduces well the spin-dependent structure functions measured at high Q 2. Comparisons with experimental observations and some other polarized parton distribution functions are also shown. Our results are in good agreement with the experimental data and consistent with some other parameterized models. Furthermore, our analysis presents the positive polarized gluon distribution and it suggests that the gluon distribution plays an important role to the proton spin content. The polarized antiquark distributions are non-zero at high Q 2 but quite small compared to polarized valence quark distributions, based on this dynamical parton model analysis. This analysis gives smaller statistical uncertainties for the polarized sea quark and gluon distributions, thanks to the fewer free parameters used for the parametrization of the initial polarized PDFs. [ABSTRACT FROM AUTHOR]

Valence quark distributions of pion at very low resolution scale Q 0 2 ∼ 0.1 GeV2 are deduced from a maximum entropy method, under the assumption that pion consists of only a valence quark and a valence anti-quark at such a low scale. Taking the obtained initial quark distributions as the nonperturbative input in the modified Dokshitzer-Gribov-Lipatov-Altarelli-Parisi (with the GLR-MQ-ZRS corrections) evolution, the generated valence quark distribution functions at high Q 2 are consistent with the measured ones from a Drell-Yan experiment. The maximum entropy method is also applied to estimate the valence quark distributions at relatively higher Q 2 = 0.26 GeV 2. At this higher scale, other components (sea quarks and gluons) should be considered in order to match the experimental data. The first three moments of pion quark distributions at high Q 2 are calculated and compared with the other theoretical predictions. [ABSTRACT FROM AUTHOR]

Recently, magnetic field (MF) has been described as a potential way to improve the properties of electrode materials, which significantly enhances the ion diffusion behavior and material wettability. We first synthezised for the first time a comparable carbon-based electrode material (GCA) including active carbon, reduced graphene and carbon nanotubes through a facile stirring method for further research under MF. Herein, 0.15 T of MF induced by two NdFeB magnets was applied on the supercapacitor devices to enhance the energy density, which increased by about 62% for the symmetric supercapacitor (SSC: from 11.2 to 18.1 W h kg−1). An asymmetric supercapacitor composed of the prepared GCA as the anode and NiCoFe/NiCoFe–OH as the cathode was also assembled for research. And it was found that the whole electrochemical performance significantly improved (for example, energy density increased by about 22% for the asymmetric supercapacitor, i.e., from 50.6 to 61.4 W h kg−1). [ABSTRACT FROM AUTHOR]

The rational construction of the active materials with hierarchical structure is a feasible and effective strategy for realizing high electrochemical performance of supercapacitors. Herein, ultra-thin nickel hydroxide nanosheets are directly grow on the external surface of Ni 3 S 2 nanorod arrays grew on nickel foam through simple hydrothermal ways to form Ni 3 S 2 /Ni(OH) 2 hierarchical nanoarrays. The Ni 3 S 2 nanorod arrays synthesized on nickel foam using hydrogen peroxide as an inducer could not only serve as the main channel for charge transport but also support the growth of active materials, moreover, the exposed active parts can also participate in the electrochemical energy storage process. The external ultra-thin nickel hydroxide nanosheets augment the contact region with the electrolyte and enrich the electrochemical active sites. The Ni 3 S 2 /Ni(OH) 2 composite exhibits wonderful electrochemical performance is on account of its hierarchical structure could augment the effective specific surface area of electrode materials and induce a synergistic effect between each component. The aquaired Ni 3 S 2 /Ni(OH) 2 electrode presents a brilliant specific capacitance (826 ​C ​g−1 during 1 ​A ​g−1) and relatively good rate performance (50% retention during 20 ​A ​g−1). In addition, our prepared hybrid supercapacitor used Ni 3 S 2 /Ni(OH) 2 and AC acted as cathode and anode, respectively, gives rise to a superior energy density of 48.3 ​Wh kg−1 at about 800 ​W ​kg−1 of power density, together with retained about 70% capacitance after 10000 cycles at 5 ​A ​g−1. Meanwhile, two hybrid supercapacitor devices were fabricated in series to power a white LED, which can be continuously lit for more than 8 ​min. Herein, ultra-thin Ni(OH) 2 nanosheets are directly grow on the surface of Ni 3 S 2 nanorod arrays supported on nickel foam. Two Ni 3 S 2 /Ni(OH) 2 //AC hybrid supercapacitor devices can lighten a white LED for more than 8 ​min. [Display omitted] • The ultra-thin nanosheets combined with nanorod arrays structure enhance electrochemical performances. • A simple two-step hydrothermal method is developed. • Two Ni 3 S 2 /Ni(OH) 2 //AC hybrid supercapacitors in series can power a white LED for more than 8 ​min.. [ABSTRACT FROM AUTHOR]

The structure of Fe 2 O 3 @NiS/Co 3 S 4 composite was the agglomerate Fe 2 O 3 nanoparticles in situ covered with NiS/Co 3 S 4 nanosheets and the composite employed for high-performance supercapacitor electrode. [Display omitted] • The Fe 2 O 3 -based composite as cathode materials are few reports. • Synergetic effects between Fe 2 O 3 and NiCo-S improve the capacity and conductivity. • Fe 2 O 3 @Ni1Co1-S presented 3D stable open structure lead to the electrode stability. • The corresponding ASC device delivers considerable energy and power densities. Fe 2 O 3 -based cathode materials show high theoretical specific capacitance and a wide potential range, but it is limited development due to poor electrical conductivity, undesired rate capacity and long-term cycling stability. Herein, we introduce the interconnected NiS/Co 3 S 4 nanosheets grown on Fe 2 O 3 substrate (Fe 2 O 3 @NiS/Co 3 S 4) through a facile in situ solution vulcanization process. Because of the synergistic effect between the Fe 2 O 3 nanoparticles and NiCo-S nanosheets and its unique three-dimensional open structure providing abundant channels and active sites, it is deeply investigated the electrochemical performances as positive material of supercapacitors. Meanwhile, the electrode material exhibits specific capacity of 1213.7 F g−1 at 1 A g−1, about 64.7% capacity retention at 10 A g−1 and steady cycling performance about 85.2% retention after 5000 cycles at 5 A g−1. Finally, an asymmetric supercapacitor was assembled based on Fe 2 O 3 @NiS/Co 3 S 4 and active carbon as the positive and negative electrodes. The energy density is 43.8 Wh kg−1 at the power density of 810 W kg−1. At the same time, 92.4 % capacitance retention after 10,000 cycles at 5 A g−1 was obtained. [ABSTRACT FROM AUTHOR]