Health effects of arsenic；fluorine；and selenium from indoor burning of Chinese coal

IEECAS SKLLQG

The air pollution caused by the burning of fireworks during the lantern festival in Beijing

IEECAS SKLLQG

Measurement of the inelastic branch of the O-14(alpha, p)F-17 reaction: Implications for explosive burning in novae and x-ray bursters

A measurement of the inelastic component of the key astrophysical resonance in the 14O(α,p)17F reaction for burning and breakout from hot carbon-nitrogen-oxygen (CNO) cycles is reported. The inelastic component is found to be comparable to the ground-state branch and will enhance the 14O(α,p)17F reaction rate. The current results for the reaction rate confirm that the 14O(α,p)17F reaction is unlikely to contribute substantially to burning and breakout from the CNO cycles under novae conditions. The reaction can, however, contribute strongly to the breakout from the hot CNO cycles under the more extreme conditions found in x-ray bursters.

Measurement of the inelastic branch of the stellar O-14(alpha,p)F-17 reaction occurring in the explosive burning in Novae and X-ray busters

The inelastic component of the key astrophysical resonance (1(-), E-x=6.15 MeV) in the O-14(alpha,p)F-17 reaction has been studied by using the resonant scattering of F-17+p. The experiment was done at REX-ISOLDE CERN with the Miniball setup. The thick target method in inverse kinematics was utilized in the present experiment where a 44.2 MeV F-17 beam bombarded a similar to 40 mu m thick (CH2)(n) target. The inelastic scattering protons in coincidence with the de-excited 495 keV gamma rays have been clearly seen and they are from the inelastic branch to the first excited state in F-17 following decay of the 1(-) resonance in Ne-18. Some preliminary results are reported.

vertical growth of thalassia testudinum seasonal and interannual variability

The vertical growth of shoots of the seagrass Thalassia testudinum Banks ex Konig in four meadows, along a range of exposure to waves, in the Mexican Caribbean was examined to elucidate its magnitude and its relationship to sediment dynamics. Average internodal length varied between 0.17 and 12.75 mm, and was greatest in the meadow which experienced the greatest burial by sand waves moved by Hurricane Gilbert (September 1988). Internodal length showed annual cycles, confirmed by the flower scars always preceding or coinciding with the annual minimum internodal length. These annual cycles on the shoot allowed estimation of annual leaf production, which varied, on average, between 14.2 and 19.3 leaves per shoot year-1. High vertical shoot growth was associated with long internodes and high leaf production rate, which increased with increasing vertical shoot growth to a maximum of approximately 25 leaves per shoot year-1, with vertical growth of about 30 mm year-1 or more. Average internodal length showed substantial interannual differences from perturbations derived from the passage of Hurricane Gilbert. The growth response of the plants surviving moderate burial and erosion after the hurricane involved enhanced vertical growth and increased leaf production, and reduced vertical growth, respectively, after 1988. The variability in shoot vertical growth of T testudinum can be separated into seasonal changes in plant growth, and long-term variability associated with episodic perturbations involving sediment redistribution by hurricanes.

Coal-burning roasted corn and chili as the cause of dental fluorosis for children in southwestern China

To find the pathologic cause of the children's dental fluorosis in southwestern China, diet structure before the age of 6 and prevalence rate of dental fluorosis (DF) of 405 children were investigated, and the fluorine and arsenic content of several materials were determined. The prevalence rate of DF of children living on roasted corn before the age of 6 is 100% with nearly 95% having the mild to severe DF; while that of children living on non-roasted corn or rice is less than 5% with all having very mild DF. The average fluorine and arsenic concentration are 20.26 mg/kg and 0.249 mg/kg in roasted corn, which are about 16 times and 35 times more than in non-roasted corn, respectively. The average fluorine concentration is 78 mg/kg in coal, 1116 mg/kg in binder clay and 313 mg/kg in briquette (coal mixed with clay). The average arsenic concentration of coal is 5.83 mg/kg, the binder clay is 20.94 mg/kg, with 8.52 mg/kg in the briquette. Living on roasted corn and chili is the main pathologic cause of endemic fluorosis in southwestern China. The main source of fluorine and arsenic pollution of roasted corn and chill is the briquette of coal and binder clay. (C) 2010 Elsevier B.V. All rights reserved.

Vertical structure p-type permeable metal-base organic transistors based on N,N '-diphentyl-N,N '-bis(1-naphthylphenyl)-1,1 '-biphenyl-4,4 '-diamine

In this article, vertical structure p-type permeable-base organic transistors were proposed and demonstrated. A hole-type organic semiconductor N,N-'-diphentyl-N,N-'-bis(1-naphthylphenyl)-1,1(')-biphenyl-4,4(')-diamine was used as emitter and collector. In the permeable-base transistors, the metal base was formed by firstly coevaporating Al and Ca in vacuum and then annealing at 120 degrees C for 5 min in air, followed by a thin Al deposition. These devices show a common-base current gain of near 1.0 and a common-emitter current gain of similar to 270.

Vertical structure permeable-base hybrid transistors based on multilayered metal base for stable electrical characteristics

In this work we present a permeable base transistor consisting of a 60 nm thick N,N'diphenyl-N,N'-bis(1-naphthylphenyl)-1,1'-biphenyl-4,4'-diamine layer or a 40 nm thick 2,6-diphenyl-indenofluorene layer as the emitter, a CalAl/Ca multilayer as the metal base, and p-Si as collector. In the base, the Ca layers are 5 nm thick and the Al layer was varied between 10 and 40 nm. the best results obtained with a 20 nm thick layer. The devices present common-base current gain with both organic layer and silicon acting as emitter, but there is only observable common-emitter current gain when the organic semiconductor acts as emitter. The obtained common-emitter current gain, similar to 2, is independent on collector-emitter voltage, base current and organic emitter in a reasonable wide interval. Air exposure or annealing of the base is necessary to achieve these characteristics, indicating that an oxide layer is beneficial to proper device operation.

Colloidal crystal heterostructures by a two-step vertical deposition method

A two-step template-induced vertical deposition technique was introduced to fabricate the colloidal crystal heterostructures due to wettability differences and spatial confinement of the templates structured with microchannels. The heterostructures exhibited a bi-frequency Bragg diffraction whose position was determined by the microsphere diameter of the opals. It was demonstrated that the channel width had an influence on the optical properties of the colloidal crystal heterostructures. The strategy proposed is suited for fabrication of different micron-sized opal architectures with complex form and designed optical functionality.