Because of the needs of sustainable development of the mankind society and natural environment building a renewable energy system is one of the most critical issues that today's society must address. ...In the new energy system there is a requirement for a renewable fuel to replace current energy carrier. Hydrogen is an ideal secondary energy. Using solar energy to produce hydrogen in large scale can solve the problems of sustainability, environmental emissions, and energy security and become the focus of the international society in the area of energy science and technology. It has also been set as an important research direction by many international hydrogen programs. The Ministry of Science and Technology of China supported and launched a project of
National Basic Research Program of China (973 Program) – the
Basic Research of Mass Hydrogen Production using Solar Energy in 2003 for R&D in the areas of solar hydrogen production. The current status of solar hydrogen production research is reviewed and some significant results achieved in the project are reported in this paper. The trends of development and the future research directions in the field of solar hydrogen production in China are also briefly discussed.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
The authors constructed multiferroic structures by growing La0.9Ce0.1MnO3 (LCEMO) thin films on piezoelectric 0.68Pb(Mg1/3Nb2/3)O3–0.32PbTiO3 (PMN-PT) single-crystal substrates. Due to the efficient ...elastic coupling at the interface, the electric-field-induced piezoelectric strain in PMN-PT substrates is effectively transferred to LCEMO films and thus, leads to a decrease in the resistance and an increase in the magnetoresistance of the films. Particularly, it was found that the resistance-strain coefficient ΔR/Rfilm/Δεzzfilm of the LCEMO film was considerably enhanced by the application of magnetic fields, demonstrating strong coupling between the lattice and the spin degrees of freedom. ΔR/Rfilm/Δεzzfilm at 122K was enhanced by ~28.8% by a magnetic field of 1.2T. An analysis of the overall results demonstrates that the phase separation is crucial to understand strain-mediated modulation of electronic transport properties of manganite film/PMN-PT multiferroic structures.
► La0.9Ce0.1MnO3 films were epitaxially grown on piezoelectric single crystals. ► Piezoelectric strain influences the electronic transport properties of films. ► Magnetic field enhances the piezoelectric strain effect. ► Phase separation is crucial to understand the piezoelectric strain effect.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Based on a data sample of (2712.4±14.3)×10 6 ψ(3686) events collected with the BESIII detector at the BEPCII collider, the M1 transition ψ(3686)→γη c (2S) with η c( 2S)→K¯Kπ is studied, where K¯Kπ is ...K + K − π 0 or K 0 S K ± π ∓ . The mass and width of the η c (2S) are measured to be (3637.8±0.8(stat)±0.2(syst)) MeV/c 2 and (10.5±1.7(stat)±3.5(syst)) MeV, respectively. The product branching fraction B(ψ(3686)→γη c (2S))×B(η c (2S)→K¯Kπ) is determined to be (0.97±0.06(stat)±0.09(syst))×10 −5 . Using B(η c (2S)→K¯Kπ)=(1.86 +0.68 −0.49 )%, we obtain the branching fraction of the radiative transition to be B(ψ(3686)→γη c (2S))=(5.2±0.3(stat)±0.5(syst) +1.9 −1.4 (extr))×10 −4 , where the third uncertainty is due to the quoted B(η c (2S)→K¯Kπ).
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CMK, CTK, FMFMET, IJS, NUK, PNG, UM
Al-doped zinc oxide (AZO) films are prepared on quartz substrates by dual-ion-beam sputtering deposition at room temperature (∼25°C). An assisting argon ion beam (ion energy
E
i
=0–300 eV) directly ...bombards the substrate surface to modify the properties of AZO films. The effects of assisted-ion beam energy on the characteristics of AZO films were investigated in terms of X-ray diffraction, atomic force microscopy, Raman spectra, Hall measurement and optical transmittance. With increasing assisting-ion beam bombardment, AZO films have a strong improved crystalline quality and increased radiation damage such as oxygen vacancies and zinc interstitials. The lowest resistivity of 4.9×10
−3
Ω cm and highest transmittance of above 85% in the visible region were obtained under the assisting-ion beam energy 200 eV. It was found that the bandgap of AZO films increased from 3.37 to 3.59 eV when the assisting-ion beam energy increased from 0 to 300 eV.
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DOBA, EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, IZUM, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, SIK, UILJ, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Based on a data sample of 10 billion J / ψ events collected with the BESIII detector, improved measurements of the Dalitz decays η / η ′ → γ e + e − are performed, where the η and η ′ are produced ...through the radiative decays J / ψ → γ η / η ′ . The branching fractions of η → γ e + e − and η ′ → γ e + e − are measured to be ( 7.07 ± 0.05 ± 0.23 ) × 10 − 3 and ( 4.83 ± 0.07 ± 0.14 ) × 10 − 4 , respectively. Within the single-pole model, the parameter of electromagnetic transition form factor for η → γ e + e − is determined to be Λ η = ( 0.749 ± 0.027 ± 0.007 ) GeV / c 2 . Within the multipole model, we extract the electromagnetic transition form factors for η ′ → γ e + e − to be Λ η ′ = ( 0.802 ± 0.007 ± 0.008 ) GeV / c 2 and γ η ′ = ( 0.113 ± 0.010 ± 0.002 ) GeV / c 2 . The results are consistent with both theoretical predictions and previous measurements. The characteristic sizes of the interaction regions for the η and η ′ are calculated to be ( 0.645 ± 0.023 ± 0.007 ) fm and ( 0.596 ± 0.005 ± 0.006 ) fm , respectively. In addition, we search for the dark photon in η / η ′ → γ e + e − , and the upper limits of the branching fractions as a function of the dark photon are given at 90% confidence level. Published by the American Physical Society 2024
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Using e + e − collision data collected with the BESIII detector operating at the BEPCII collider, the Born cross sections of e + e − → Λ c + Λ ¯ c ( 2595 ) − + c . c . and e + e − → Λ c + Λ ¯ c ( ...2625 ) − + c . c . are measured for the first time at center-of-mass energies of s = 4918.0 and 4950.9 MeV. Nonzero cross sections are observed very close to the production threshold. The measured Born cross sections of e + e − → Λ c + Λ ¯ c ( 2625 ) − + c . c . are about 2–3 times greater than those of e + e − → Λ c + Λ ¯ c ( 2595 ) − + c . c . , providing the similar behavior as semileptonic decays of Λ b 0 , but different behavior from that in the hadronic decays of Λ b 0 . The Born cross sections are 15.6 ± 3.1 ± 0.9 pb and 29.4 ± 3.7 ± 2.7 pb for e + e − → Λ c + Λ ¯ c ( 2595 ) − + c . c . , and are 43.4 ± 4.0 ± 4.1 pb and 76.8 ± 6.5 ± 4.2 pb for e + e − → Λ c + Λ ¯ c ( 2625 ) − + c . c . at s = 4918.0 and 4950.9 MeV, respectively. Based on the polar angle distributions of the Λ ¯ c ( 2625 ) − and Λ c ( 2625 ) + , the form-factor ratios | G E | 2 + 3 | G M | 2 / | G C | are determined for e + e − → Λ c + Λ ¯ c ( 2625 ) − + c . c . for the first time, which are 5.95 ± 4.07 ± 0.15 and 0.94 ± 0.32 ± 0.02 at s = 4918.0 and 4950.9 MeV, respectively. All of these first uncertainties are statistical and second systematic. Published by the American Physical Society 2024
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