ALBERT

Description: X-ray photoelectron spectroscopy (XPS) was utilized to measure the valence band offset (Δ E V ) of the TiZnSnO (TZTO)/Si heterojunction. TZTO films were deposited on Si (100) substrates using magnetron sputtering at room temperature. By using the Zn 2 p 3/2 and Sn 3 d 5/2 energy levels as references, the value of Δ E V was calculated to be 2.69 ± 0.1 eV. Combining with the experimental optical energy band gap of 3.98 eV for TZTO extracted from the UV-vis transmittance spectrum, the conduction band offset (Δ E C ) was deduced to be 0.17 ± 0.1 eV at the interface. Hence, the energy band alignment of the heterojunction was determined accurately, showing a type-I form. This will be beneficial for the design and application of TZTO/Si hybrid devices.

Description: The transition-metal dichalcogenides provided a good platform for the investigation of superconductivity and charge-density-wave (CDW) order. A series of high quality 6 R -TaS 2− x Se x (0 ≤  x  ≤ 1.6) single crystals were fabricated by the chemical-vapor-transport method and systematically investigated. The CDW becomes more stable with more S being replaced by Se, which causes expansion of the lattice, and produces a negative chemical pressure in the system. The x dependence of the onset of superconductivity ( T c onset ) shows a dome-like shape with a maximum of T c onset  = 2.7 K at x  = 0.8. The magnetic susceptibility (4π χ ) of x  = 0.8 under the hydrostatic pressure P  = 1.0 GPa was also measured, which showed a small increase of T c and superconducting volume fraction. A pronounced peak effect was observed in the isothermal hysteresis with magnetic field ( H ) parallel to c -axis, which may arise from the quenching inhomogeneity and/or the stacking disorder. Finally, the evolution of the electronic states tuned by Se-doping was summarized in the phase diagram.

Description: Two different confinement transition discharges, the low-intermediate-high (L-I-H) and the low-intermediate-low (L-I-L) confinement transitions, respectively, have been obtained by lower hybrid current drive with lithium wall conditioning in the EAST superconducting tokamak. The dynamic features of short-scale turbulent fluctuations in the two discharges are investigated by a tangential CO 2 laser collective scattering system. It is found that the great changes of broadband fluctuations in amplitude and structure characteristics are closely related to the choice of the final transition to H-mode. These results could shed light on the understanding of the L-H transition mechanism.

Description: Atmospheric particle pollution is a serious environmental issue in China, especially the northern regions. Ambient air loadings (ng m−3), pollution sources and apportionment, and transport pathways of trace (Cd, Co, Cu, Ni, Pb, V, and Zn) and major (Al, Ca, Fe, and Mg) metals associated with inhalable particulate matters (PM10 aerosols) were characterized in urban, rural village, and rural field areas of seven cities (from inland in the west to the coast in the east: Wuwei, Yinchuan, Taiyuan, Beijing, Dezhou, Yantai, and Dalian) across northern China by taking one 72 h sample each site within a month for a whole year (April 2010 to March 2011). Ambient PM10 pollution in northern China is especially significant in the cold season (October–March) due to the combustion of coal for heating and dust storms in the winter and spring. Owing to variations in emission intensity and meteorological conditions, there is a trend of decrease in PM10 levels in cities from west to east. Both air PM10 and the associated metal loadings for urban and rural areas were comparable, showing that the current pattern of regional pollution in China differs from the decreasing urban–rural-background transect that is usual in other parts of the world. The average metal levels are Zn (276 ng m−3) ≫ Pb (93.7) ≫ Cu (54.9) ≫ Ni (9.37) 〉 V (8.34) ≫ Cd (2.84) 〉 Co (1.76). Judging from concentrations (mg kg−1), enrichment factors (EFs), a multivariate statistical analysis (principal component analysis, PCA), and a receptor model (absolute principal component scores-multiple linear regression analysis, APCS-MLR), the airborne trace metals (Zn, Pb, Cu, and Cd) in northern China were mainly anthropogenic, and mostly attributable to coal combustion and vehicle emissions with additional industrial sources. However, the Co was mostly of crustal origin, and the V and Ni were mainly from soil/dust in the western region and mostly from the petrochemical industry/oil combustion in the east. The accumulation of typical "urban metals" (Pb, Zn, Cd, and Cu) showed a trend of increase from west to east, indicating their higher anthropogenic contribution in eastern cities. The winter northwestern monsoon and westerly jet stream were the dominant forces in the long-range transport of airborne PM metals in northern China, with potentially global implications.