[en] The see-saw mechanism is usually applied to explain the lightness of neutrinos. The traditional see-saw mechanism introduces at least two right-handed neutrinos for the realistic neutrino spectrum. In the case of supersymmetry, loop corrections can also contribute to neutrino masses, which lead to the possibility to generate the neutrino spectrum by introducing just one right-handed neutrino. To be realistic, MSSM suffers from the μ problem and other phenomenological difficulties, so we extend NMSSM (the MSSM with a singlet S) by introducing one single right-handed neutrino superfield (N) and relevant phenomenology is discussed

[en] (Sr_1−xCa_x)Nd₂Al₂O₇ (x = 0, 0.1, 0.3, 0.5) ceramics were synthesized by a standard solid state reaction method. Their microwave dielectric properties were investigated together with the structural evolution. X-ray diffraction analysis indicated that Ruddlesden–Popper solid solutions with n = 2 were obtained for all the compositions investigated here. Ca-substitution significantly improved the densification behavior which was associated with the variation of ε_r. More importantly, with increasing the content of Ca, τ_f value was generally improved towards near-zero, and the significantly improved Qf value was obtained at x = 0.5. The stacking fault and distorted lattice fringe in the ceramics were confirmed by TEM observation, and these defects were deeply concerned with the microwave dielectric loss. The best combination of microwave dielectric characteristics was achieved for the composition of x = 0.5: ε_r = 21.1, Qf = 68,200 GHz and τ_f = −0.5 ppm/°C. - Highlights: • The formation of solid solutions with partial Ca substitution for Sr improved the sintering behavior of SrNd₂Al₂O₇ ceramics. • Stacking fault and distorted lattice fringe were confirmed by transmission electron microscopy. • The variation of Qf value was associated with the stacking fault and distorted lattice fringe

[en] Cu_2ZnSnS_4 (CZTS) thin films were grown on Mo-coated Soda-lime-glass (SLG) substrates by sulfurization of sputtered ZnS/Sn/CuS precursors at different temperatures i.e. 560 °C, 580 °C and 600 °C. The effects of sulfurization temperature on the quality of CZTS thin films and solar cells were investigated. The crystal structure, surface morphology, chemical composition, phase purity and surface roughness of CZTS thin films fabricated at different sulfurization temperatures were characterized by X Ray Diffraction (XRD), scanning electron microscopy (SEM) equipped with an energy dispersive spectrometer (EDS), Raman spectroscopy and atomic force microscope (AFM), respectively. The results show that all CZTS thin films exhibit a polycrystalline kesterite structure and preferred (112) orientation. For the sulfurization temperature of 580 °C, the obtained CZTS thin films are dense and flat with larger grain size. Meanwhile composition studying indicates that the fabricated CZTS with single phase is copper poor and zinc rich. Furthermore, the surface roughness of CZTS film is the lowest. Finally, the CZTS solar cells with the structure of SLG/Mo/CZTS/CdS/i-ZnO/ITO/Al were fabricated and demonstrated the best power conversion efficiency of 3.59% when used sulfurization temperature was 580 °C.

[en] Highlights: • Uniform Ni nanoparticles were synthesized. • A Ni nanoparticle-modified imprinted sensor was developed to detect phenobarbital. • The modified sensor exhibited high sensitivity for phenobarbital. • The electrochemical properties of the modified sensor were investigated. • The prepared sensor was applied to detect phenobarbital in fish samples. - Abstract: Uniform nickel nanoparticles were applied to improve the sensitivity of sensors for phenobarbital (PB) determination. A Ni nanoparticle-modified imprinted electrochemical sensor was developed by thermal polymerization with the use of methacrylic acid as the functional monomer and ethylene glycol maleic rosinate acrylate as the crosslinking agent. The chemical structures and morphologies of the imprinted films were characterized using Fourier transform infrared spectroscopy and scanning electron microscopy. The success of the fabrication of Ni nanoparticles, as well as the Ni nanoparticle-modified imprinted electrochemical sensor, was confirmed by the analytical results. The electrochemical properties of the modified molecularly imprinted and non-imprinted polymer sensors were investigated by cyclic voltammetry, differential pulse voltammetry, electrochemical impedance spectroscopy, and chronoamperometry. Results showed that the electrochemical properties of the molecularly imprinted sensor were remarkably different from those of the non-imprinted sensor. Linear responses of the imprinted sensor to PB were observed for concentrations ranging from 1.4 × 10"−"7 mol L"−"1 to 1.3 × 10"−"4 mol L"−"1 (r"2 = 0.9976), with a detection limit of 8.2 × 10"−"9 mol L"−"1 (S/N = 3). The imprinted electrochemical sensor was used to determine PB in actual fish samples, in which average recoveries between 95.60% and 104.67% were achieved. The developed Ni nanoparticle-modified electrochemical sensor exhibited high sensitivity, high selectivity, and good recovery

[en] We consider the thermal effects into the evaluation of the dark matter production process. With the assistance of the right handed neutrinos, the freeze-in massive particle dark matter production history can be modified by the two-step phase transitions. The kinematic of decay/inverse decay or annihilation processes can be affected by the finite temperature effects as the Universe cools down. The history of the symmetry respected by the model can be revealed by the DM relic abundance evolution processes. The strong first order electroweak phase transition generated gravitational waves can be probed. The number of extra scalars for the Hierarchy problem can be probed through the Higgs off-shell searches at the LHC.

[en] The high power RF transmitter and the circulator with 500 MHz/250 kW which will be operated in Beijing Electron-Positron Collider Upgrade (BEPC II) project have been installed on site, and adjustments and acceptance test have been finished, which is the first transmitter system of 500 MHz/250 kW in China. In this paper, the test principle and all measurements as well as commissioning result in the acceptance test are introduced in details, and the actual machine technical parameters and performance are presented. An acceptance test conclusion by comparing with the design requirements is given. (authors)

[en] Modification of silica gel by butanedioic anhydride (SiO₂–BDAH) results in efficient adsorbents for removal of U(VI), Th(IV), and Eu(III) from aqueous solutions. SiO₂–BDAH was characterized by Fourier Transform infrared spectroscopy, elemental analysis, N₂ adsorption–desorption isotherms, thermogravimetic analysis, and potentiometric titration. The effect of contact time, pH, and initial concentration of radioactive solutions and temperature on the adsorption capacity of the sorbent was investigated. The sorption equilibrium times of U(VI), Th(IV), and Eu(III) onto SiO₂–BDAH were 1.5, 2, and about 10 h. The sorption percentages of U(VI), Th(IV), and Eu(III) increased with increased pH from 1 to 5. The sorption process of U(VI), Th(IV), and Eu(III) can be described by the Langmuir model, with sorption capacities of 5.10 × 10⁻⁵, 5.06 × 10⁻⁵, and 3.44 × 10⁻⁵ mol/L, respectively. The enthalpy and entropy changes were all positive, whereas the free energy changes were negative. This study indicated that SiO₂–BDAH can remove U(VI) and Th(IV) at the same time in the presence of multiple ions from waste water quickly.

[en] Highlights: • Supercritical water gasification of cationic exchange resin was studied. • The carbon gasification efficiency was up to 97.98% with K₂CO₃ addition. • The intermediate compounds have been meticulously investigated and identified. • The formation and pathways of gasification reaction were proposed and discussed. Spent ion exchange resins produced by nuclear power plants are radioactive organic waste. Until now, there is no satisfactory industrial treatment. Supercritical water gasification (SCWG) of cationic ion exchange resin (CIER) used in nuclear power plants was carried out in a batch reactor in this study. Results showed that the gasification efficiency increased with the growth of temperature (550–750 °C), addition of alkali homogeneous catalyst (K₂CO₃), proper ratio loading of catalyst to CIER (1:1), decrease of feed concentration (2–10 wt%) and extension of residence time (10–60 min). Carbon gasification efficiency was up to 97.98% with K₂CO₃ added and 30 min at 750 °C in the batch reactor. The gaseous products mainly consist of H₂, CO, CO₂ and CH₄. The GC–MS analysis showed that the organic component in liquid products was mainly composed of benzene, monocycle arenes, phenol group and polycyclic aromatic hydrocarbons. Based on the experimental results, the formation and gasification pathways of CIER in SCW were proposed.

[en] Tensile flow behaviors of the fine-grained ZK60 alloy sheet are investigated from 298 K to 523 K with strain rates from 10⁻¹ s⁻¹ to 10⁻³ s⁻¹. The apparent activation energy tested at 523 K is estimated to be 103 kJ mol⁻¹, indicating that grain-boundary sliding (GBS) associated with grain boundary diffusion is the dominant deformation mechanism of the fine-grained ZK60 alloy. The effects of deformation temperature and strain rate on the strain-hardening and strain-softening behaviors are analyzed by the K-M approach. The results show that the dislocation proliferation contributes to the hardening process but DRX play an important role in the softening process. (paper)

[en] We present a systematic experimental investigation on visible light collimation by a nanostructured slit flanked with a pair of periodic array of grooves in gold thin film. A wide variety of aspects are considered, such as the polarization state, the transport path of incident light, the groove—groove spacing, the groove width and depth. Our results clearly show that the relationship between the collimation wavelength and the periodicity of the slit-groove structure accords well with the surface plasmon dispersion model proposed by previous researchers. Furthermore, the surface plasmon wave phase retardation effect induced by the surface structure is also verified via the measurement for samples with different groove widths and depths. These results indicate that the detailed geometry of the groove structure has obvious impacts on the collimation effect and the angular distribution of the diffraction light in the subwavelength plasmonic system. (condensed matter: electronic structure, electrical, magnetic, and optical properties)