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Polycrystalline α-Ga2O3 thin films containing secondary phase SnO were grown on BaF2 substrates by magnetron sputtering. The impurity tin concentration, electron concentration, and room temperature mobility of the α-Ga2O3 films are 4.5 × 1020 cm−3, 1.5 × 1015 cm−3, and 26.9 cm2 V−1 s−1, respectively, determined by secondary ion mass spectrometry and Hall effect experiments. The mobility vs temperature dependence confirms that the electrons are mainly subject to polar optical phonon scattering and ionized impurity scattering in the temperature range of 160–400 K. Two ionization energies, 29 and 71 meV, were determined for different temperature ranges by logarithmic resistivity vs the reciprocal of temperature, where the former is the shallow donor SnGa formed by the incorporation of tin into gallium sites. The latter is the shallow acceptor VSn–H associated with secondary phase SnO, and it is the electrical compensation of this shallow acceptor that results in the very low carrier concentration of α-Ga2O3 films. The photoluminescence spectrum exhibits 280 and 320 nm UV radiation, where 280 nm is due to the radiation recombination of electrons trapped by the deep donor state (EC−1.1 eV) with holes trapped by the VSn–H complex. In addition, there are several narrow radiation peaks in the visible region, and the energy levels involved in the radiation transitions are determined one by one after excluding the effects of interference and diffraction. [ABSTRACT FROM AUTHOR]

With more accurate measurement method for gas samples, cross sections of the 14N(n,α0,1)11B reactions were measured at 24 energy points in the 4.5–11.5 MeV neutron energy region based on the 4.5 MV Van de Graaff accelerator at Peking University and the HI-13 tandem accelerator of China Institute of Atomic Energy (CIAE). The average neutron fluence (Φ) through the gas sample was obtained through the combination of a highly enriched 238U3O8 sample and the simulation based on SuperMC. The cross sections of the 14N(n,α0)11B reaction measured using the gas sample and the solid samples are in agreement with each other. R-matrix analysis was carried out for the n + 14N system using code RAC in the neutron energy region below 30 MeV. A possible valley structure in both the excitation functions of the 14N(n,α0,1)11B reactions in the 10–11 MeV neutron energy region was found for the first time. [ABSTRACT FROM AUTHOR]

We present an optical absorption model that integrates wavelength dependence of two- and three-photon absorption (2PA and 3PA) and free carrier absorption (FCA) coefficients in the below bandgap regime. The model can be termed as the characteristic function for the below bandgap absorption. The measured absorption spectrum of the PbTe film using Fourier transform infrared spectroscopy agrees well with the modeled optical properties. 2PA, 3PA, and FCA coefficients in cm − 1 for the entire wavelength range can be obtained from a single measurement of the below bandgap absorption spectrum. The results indicate that the remarkable 2PA and 3PA processes occur in the wavelength range from 4.18 to 7.58 μ m. In addition, we implement the model in the below bandgap absorption spectra of n-Si with the room temperature carrier concentration 1.0 × 10 − 19 cm − 3 . The predicted 2PA values by the model in cm − 1 are 5.38–0.53 cm − 1 in the wavelength range from 1.1 to 2.2 μ m and agree well with experimental 2PA values at 1.55 μ m wavelengths by the Z-scan measurement. Our paper offers an effective method in handling the below bandgap absorption measurement. [ABSTRACT FROM AUTHOR]

Nuclear data with high accuracy for minor actinides play an important role in nuclear technology applications, including reactor design and operation, fuel cycle, estimation of the amount of minor actinides in high burn-up reactors and the minor actinides transmutation. Based on a new set of neutron optical model parameter and the reaction cross section systematics of fissile isotopes, a full set of 236,238Np neutron reaction data from 10−5 eV ∼20 MeV are updated and improved through theoretical calculation. Mainly revised quantities include the total, elastic, inelastic, fission, (n, 2n) and (n, γ) reaction cross sections as well as angular distribution etc. The promising results are obtained when the renewal evaluated data of 236,238Np will replace the evaluated data in CENDL-3.1 database.

Wang, S.; Jiang, J., and Cao, W., 2019. Sealing performance evaluation method of nano-scale magnetic thin film materials in marine tanks. In: Guido-Aldana, P.A. and Mulahasan, S. (eds.), Advances in Water Resources and Exploration. Journal of Coastal Research, Special Issue No. 93, pp. 941–946. Coconut Creek (Florida), ISSN 0749-0208. In order to evaluate the sealing performance of nano-scale magnetic thin film materials in marine tanks, a method for evaluating the sealing performance of nano-scale magnetic thin film materials in marine tanks based on spatial visual image feature extraction is proposed. The differential frame point scanning and spatial vision high resolution imaging analysis method are used to collect the image information of ship tank nano-scale magnetic thin film material. The sealing gap of ship tank nano-scale magnetic film material, the weakening of material mechanics, the sealing frame point and other parts of the three-dimensional frame structure reconstitute image modeling. The edge structure feature decomposition and texture segmentation of ship tank nanoscale magnetic film material images are carried out. The stress fitting model of structural seal gap of ship tank nano-scale magnetic film material is constructed. The feature point extraction and mechanical state dynamic estimation of ship tank nano-scale magnetic film material seal gap are carried out by using three-dimensional frame structure reconstruction image feature extraction method, and the accurate prediction and evaluation of seal gap state of ship tank nano-scale magnetic film material seal are realized. The simulation results show that the sealing performance of nano-scale magnetic thin film material in ship tank is tested by this method, and the positioning accuracy of sealing gap point of nano-scale magnetic thin film material in ship tank is higher, the reliability index of closed performance evaluation is better, and the failure probability is the smallest. [ABSTRACT FROM AUTHOR]

We present the enhancement of third-order optical nonlinearity in indium tin oxide (ITO)/Au multilayer films via interfacial effects. The overall thickness of prepared ITO and Au layer was kept as 200 nm and 14 nm, respectively, and thus multilayers are 214 nm, i.e., for the sandwich structure ITO/Au/ITO, the thickness of ITO and Au is 100 nm and 14 nm, respectively, while the thickness of ITO and Au is 40 nm and 3.5 nm in the nine-layer films composed of five layers of ITO and four layers of Au. The measured nonlinear refractive index (n 2 ) and absorption coefficient (β) of the multilayers rise as the number of layers increases. The maximum n 2 and β in the nine-layer film are 2.6×10 -14 m 2 /W and -3.7×10 -8 m/W, which are 3.8 and 2.3 times larger than the values in the pure ITO film, respectively. Such enhancement of optical nonlinearity as the number of layers increases originates from the increase of carrier concentrations in multilayers due to contact of metals/semiconductors (interfacial effects), not following the traditional effective media theory and epsilon-near-zero effect. The results pave a way to modulate the optical nonlinearity in special metal-dielectric multilayers of interfacial effects and indicates the promising applications in nonlinear photonics.

Background: The potential for acute exercise to enhance attention has been discussed in the literature. However, the neural mechanisms by which acute exercise affects attention remain elusive., Method: In this study, we first identified an optimized acute Tai Chi Chuan (ATCC) exercise protocol that enhances sustained attention performance and then aimed to determine the neural substrates of exercise-enhanced attention. Reaction time (RT) from the psychomotor vigilance test (PVT) was used to evaluate sustained attention. In Experiment 1, improvements in RTs were compared among six different exercise protocols. In Experiment 2, the participants completed the PVT in an MRI scanner on both rest and exercise days., Results: Experiment 1 showed that practicing TCC 3 times for a total of 20 minutes, followed by 10-minute rest periods, resulted in the largest improvements in RTs. Experiment 2 showed that ATCC enhanced sustained attention, as evidenced by shorter RTs, and resulted in greater cuneus/precuneus activation after exercise than in the rest condition. Exercise-induced changes in brain activities across a distributed network exhibited significant correlations with attention., Conclusion: Therefore, this study indicates that ATCC effectively enhances sustained attention and underscores the key role of the cuneus/precuneus and frontoparietal-cerebellar regions in facilitating vigilance among young adults., (© The Author(s) 2022. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)