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The Al x Ga 1 -x N/Al y Ga 1 -y N multiple quantum well (MQW) structure for deep ultraviolet emission has been grown on sapphire by metal organic chemical vapor deposition (MOCVD). High resolution X-ray diffraction (HRXRD), atomic force microscopy (AFM), and cathodoluminescence (CL) are used to characterize the structural and optical properties of MQWs, respectively. Clear step flows can be observed in the AFM image indicating a two-dimensional growth model. There are many cracks on the surface of the MQW structure because of the high tensile stress. HRXRD shows multiple satellite peaks to the 2nd order. The HRXRD simulation shows that the MQW period is about 11.5 nm. The emission peak of Al x Ga 1 -x N/Al y Ga 1 -y N MQWs is about 295 nm in the deep ultraviolet region from the CL spectra.

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Single crystal CuIn3Se5 epitaxial films have been synthesized on GaAs(001) by a hybrid sputtering and evaporation technique. The microstructure, microchemistry, and selected electrical and optical properties of the films have been investigated by scanning electron microscopy, energy dispersive x-ray spectroscopy, transmission electron microscopy, cathodoluminescence, optical absorption and reflection, and four-point probe resistivity measurements. The results showed that the CuIn3Se5 crystals have an ordered point defect structure, a band gap of ≥1.18 eV, an optical absorption coefficient of about 15 000 cm−1 at a photon energy of 1.35 eV, and a film resistivity of ≳105 Ω cm. The results suggest the presence of band tails giving rise to subgap radiative recombination and absorption. Antiphase domain boundaries, stacking faults, and nanotwins were observed in the epitaxial layers and were reduced in number by rapid thermal annealing.

Resistivity, magnetization and microscopic 75 As nuclear magnetic resonance (NMR) measurements in the antiferromagnetically ordered state of the iron-based superconductor parent material CaFe2As2 exhibit anomalous features that are consistent with the collective freezing of domain walls. Below T * ≈ 10 K, the resistivity exhibits a peak and downturn, the bulk magnetization exhibits a sharp increase, and 75 As NMR measurements reveal the presence of slow fluctuations of the hyperfine field. These features in both the charge and spin response are strongly field dependent, are fully suppressed by H * ≈ 15 T, and suggest the presence of filamentary superconductivity nucleated at the antiphase domain walls in this material.

In order to evaluate impacts of different source emission on marine atmospheric particles over the South China Sea (SCS), major inorganic ionic concentrations (Na + , Cl − , SO 2− 4 , Ca 2+ , Mg 2+ , K + , NH + 4 and NO − 3 ) were determined in total suspended particulates (TSPs) at Yongxing Island, from March 2014 to February 2015. The annual average concentration of TSPs was 89.6 ± 68.0 µg m −3 , with 114.7 ± 82.1, 60.4 ± 27.0 and 59.5 ± 25.6 µg m −3 in cool, warm and transition seasons, respectively. Cl − had the highest concentration, with an annual average of 7.73 ± 5.99 µg m −3 , followed by SO 2− 4 (5.54 ± 3.65 µg m −3 ), Na + (4.00 ± 1.88 µg m −3 ),Concentrations of TSPs and the major ions showed seasonal variations, which were higher in the cool season and lower in the warm and transition seasons. Factors of influence were wind speed, temperature, relatively humidity, rain and air mass source region. Back trajectories, concentration-weighted trajectories (CWTs), and positive matrix factorization (PMF) of chemical compositions were analyzed for source apportionment, source contribution and spatiotemporal variation of major ions. Back trajectories and CWTs showed that air masses at Yongxing Island were mainly from the northeast, southwest and southeast in the cool, warm and transition seasons, respectively. The PMF results showed that 77.4 % of Na + and 99.3 % of Cl − were from sea salt; 60.5 % of NH + 4 was from oceanic emission. Anthropogenic sources were very important for atmospheric aerosols over the island. Secondary inorganic aerosol of SO 2 and NO x from fossil fuel combustion (especially coal in Chinese coastal regions) was the dominant source of NO − 3 (69.5 %) and SO 2− 4 (57.5 %).

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