Electron-Irradiation-Induced Degradation of Transfer Characteristics in Super-Junction VDMOSFET

High electric-field stress is an effective solution to the recovery of irradiated devices. In this paper, the dependence of the recovery level on the magnitude of gate voltage and duration is investigated. Compared with the scheme of high gate-bias voltage with a short stress time, the transfer characteristics are significantly recovered by applying a low electric field with a long duration. When the electric field and stress time are up to a certain value, the threshold voltage almost approaches the limitation, which is less than that before irradiation. Meanwhile, the effect of temperature on the recovery of the irradiated devices is also demonstrated. The result indicates that a high temperature of 175 °C used for the irradiated devices’ annealing does not play a role in promoting the recovery of transfer characteristics. In addition, to obtain a deep-level understanding of threshold degradation, the first-principles calculations of three Si/SiO2 interfaces are performed. It is found that new electronic states can be clearly observed in the conduction bans and valence bands after the Si-H/-OH bonds are broken by electron irradiation. However, their distribution depends on the selection of the passivation scheme. Ultimately, it can be observed that the threshold voltage linearly decreases with the increase in interface charge density. These results can provide helpful guidance in the deep interpretation of threshold degradation and the recovery of the irradiated super-junction devices.Bio-ElectronicsInteractive IntelligenceElectronic Components, Technology and Material

Site Occupancies, VUV-UV-vis Photoluminescence, and X-ray Radioluminescence of Eu²⁺-Doped RbBaPO₄

RbBaPO4:Eu2+ phosphors have been prepared by a high-temperature solid-state reaction method, and the structure was determined by Rietveld refinement based on powder X-ray diffraction (P-XRD) data. Their VUV-UV-vis photoluminescence properties are systematically investigated with three objectives: (1) based on low-temperature spectra, we clarify the site occupancies of Eu2+, and demonstrate that the doublet emission bands at ∼406 and ∼431 nm originate from Eu2+ in Ba2+ [Eu2+(I)] and Rb+ [Eu2+(II)] sites, respectively; (2) an electron-vibrational interaction (EVI) analysis is conducted to estimate the Huang-Rhys factors, the zero-phonon lines (ZPLs) and the Stokes shifts of Eu2+ in Rb+ and Ba2+ sites; (3) the studies on luminescence decay of Eu2+(I) reveal that dipole-dipole interaction is mainly responsible for the energy transfer from Eu2+(I) to Eu2+(II), and the energy migration between Eu2+(I) is weak. Finally, the X-ray excited luminescence (XEL) spectrum indicates that the light yield of the sample RbBa0.995Eu0.005PO4 is ∼17700 ph/MeV, showing its potential application in X-ray detecting. Accepted Author ManuscriptRST/Luminescence Material

Enhanced mismatch negativity in adolescents with posttraumatic stress disorder (PTSD)

The mismatch negativity (MMN) is observed following rare or unique sensory events, and reflects pre-attentional sensory processing of unexpected stimuli. The MMN is altered in several mental illnesses, including post-traumatic stress disorder (PTSD), but did not yield consistent results. We measured MMN in 27 survivors of the Wenchuan earthquake, including 13 who were diagnosed with PTSD, to determine if pre-attentive processing in the auditory cortex was altered by this disease. The amplitude of MMN was significantly greater in the PTSD group compared to the control group. In contrast, no significant group difference was found in the N1 potential, an event-related potential that reflects cortical transmission of sensory information. These results demonstrated an increased sensitivity to deviant stimuli in PTSD that may reflect a chronic state of hyperarousal and hypervigilance in trauma victims. (C) 2010 Published by Elsevier B.V

Seasonal variations and spatial distributions of perfluoroalkyl substances in the rivers Elbe and lower Weser and the North Sea

The spatial distributions and seasonal variations of perfluoroalkyl substances (PFASs) in surface waters were investigated for the German rivers Elbe and lower Weser, and the North Sea. Sigma PFAS concentrations ranged from 4.1 to 250 ng L-1 in the River Elbe, from 3.8 to 16 ng L-1 in the lower Weser, and from 0.13 to 10 ng L-1 in the North Sea. The most abundant compound was perfluorobutanesulfonate (PFBS) with a proportion of 24% in river water and 31% in seawater samples. The concentrations of perfluorohexanoic acid (PFHxA) and perfluorooctanoic acid (PFOA) in Elbe River water showed significant seasonal variation in 2011. The seasonal variations might be related to the variations of water discharge. The highest concentrations of PFOA and PFHxA were detected in August. Pearson correlations showed that perfluorobutanoic acid (PFBA) and PFBS had different sources from other PFASs, and the current manufacturing and use of C-4-based products could explain the distinction. The estimated fluxes of individual substances and Sigma PFASs in the River Elbe showed no significant seasonal variation. The annual fluxes of PFASs to the North Sea were estimated to be 335 +/- 100 kg year(-1) from the River Elbe and 102 +/- 22 kg year(-1) from the River Weser. (C) 2014 Elsevier Ltd. All rights reserved.The spatial distributions and seasonal variations of perfluoroalkyl substances (PFASs) in surface waters were investigated for the German rivers Elbe and lower Weser, and the North Sea. Sigma PFAS concentrations ranged from 4.1 to 250 ng L-1 in the River Elbe, from 3.8 to 16 ng L-1 in the lower Weser, and from 0.13 to 10 ng L-1 in the North Sea. The most abundant compound was perfluorobutanesulfonate (PFBS) with a proportion of 24% in river water and 31% in seawater samples. The concentrations of perfluorohexanoic acid (PFHxA) and perfluorooctanoic acid (PFOA) in Elbe River water showed significant seasonal variation in 2011. The seasonal variations might be related to the variations of water discharge. The highest concentrations of PFOA and PFHxA were detected in August. Pearson correlations showed that perfluorobutanoic acid (PFBA) and PFBS had different sources from other PFASs, and the current manufacturing and use of C-4-based products could explain the distinction. The estimated fluxes of individual substances and Sigma PFASs in the River Elbe showed no significant seasonal variation. The annual fluxes of PFASs to the North Sea were estimated to be 335 +/- 100 kg year(-1) from the River Elbe and 102 +/- 22 kg year(-1) from the River Weser. (C) 2014 Elsevier Ltd. All rights reserved

Spatial distribution of perfluoroalkyl acids in surface sediments of the German Bight, North Sea

Perfluoroalkyl adds (PFAAs) have been determined in the environment globally. However, studies on the occurrence of PFAAs in marine sediment remain limited. In this study, 16 PFAAs are investigated in surface sediments from the German Bight, which provided a good overview of the spatial distribution. The concentrations of Sigma PFAAs ranged from 0.056 to 7.4 ng/g dry weight. The highest concentration was found at the estuary of the River Ems, which might be the result of local discharge source. Perfluorooctane sulfonic acid (PFOS) was the dominant compound, and the enrichment of PFOS in sediment might be strongly related to the compound structure itself. The geographical condition of the German Bight influenced the movement of water and sediment, resulting in complex distribution. Following normalization according to total organic carbon (TOC) content, PFAA distributions showed a different picture. Significant linear relationships were found between total PFAA concentrations and TOC (R-2 = 0.50, p < 0.01). Compared with a previous study conducted in the same area, a declining trend was presented for the concentrations of PFOS and perfluorooctanoic acid (PFOA). Compound structure, geographical condition, and organic carbon in the sediment influence the distribution of PFAAs in the German Bight. Environmental risk assessment indicated that the risk from PFOA is negligible, whereas PFOS in marine sediment may present a risk for benthic organisms in the German Bight. (C) 2014 Elsevier B.V. All rights reserved.Perfluoroalkyl adds (PFAAs) have been determined in the environment globally. However, studies on the occurrence of PFAAs in marine sediment remain limited. In this study, 16 PFAAs are investigated in surface sediments from the German Bight, which provided a good overview of the spatial distribution. The concentrations of Sigma PFAAs ranged from 0.056 to 7.4 ng/g dry weight. The highest concentration was found at the estuary of the River Ems, which might be the result of local discharge source. Perfluorooctane sulfonic acid (PFOS) was the dominant compound, and the enrichment of PFOS in sediment might be strongly related to the compound structure itself. The geographical condition of the German Bight influenced the movement of water and sediment, resulting in complex distribution. Following normalization according to total organic carbon (TOC) content, PFAA distributions showed a different picture. Significant linear relationships were found between total PFAA concentrations and TOC (R-2 = 0.50, p < 0.01). Compared with a previous study conducted in the same area, a declining trend was presented for the concentrations of PFOS and perfluorooctanoic acid (PFOA). Compound structure, geographical condition, and organic carbon in the sediment influence the distribution of PFAAs in the German Bight. Environmental risk assessment indicated that the risk from PFOA is negligible, whereas PFOS in marine sediment may present a risk for benthic organisms in the German Bight. (C) 2014 Elsevier B.V. All rights reserved

Occurrence and dry deposition of organophosphate esters in atmospheric particles over the northern South China Sea

Nine organophosphate esters (OPEs) in airborne particles were measured during a cruise campaign over the northern South China Sea (SCS) from September to October 2013. The concentration of the total OPEs (Sigma OPEs) was 47.1-160.9 pg m(-3), which are lower than previous measurements in marine atmosphere environments. Higher OPE concentrations were observed in terrestrially influenced samples, suggesting that OPE concentrations were significantly influenced by air mass transport. Chlorinated OPEs were the dominant OPEs, accounting for 65.8-83.7% of the Sigma OPEs. Tris-(2-chloroethyl) phosphate (TCEP) was the predominant OPE compound in the samples (45.0 12.1%), followed by tris-(1-chloro-2-propyl) phosphates (TCPPs) (28.8 +/- 8.9%). Dry particle-bound deposition fluxes ranged from 8.2 to 27.8 ng m(-2) d(-1) for the Sigma OPEs. Moreover, the dry deposition input of the Sigma OPEs was estimated to be 4.98 ton y(-1) in 2013 in a vast area of northern SCS. About half of the input was found to relate to air masses originating from China. (C) 2015 Elsevier Ltd. All rights reserved.Nine organophosphate esters (OPEs) in airborne particles were measured during a cruise campaign over the northern South China Sea (SCS) from September to October 2013. The concentration of the total OPEs (Sigma OPEs) was 47.1-160.9 pg m(-3), which are lower than previous measurements in marine atmosphere environments. Higher OPE concentrations were observed in terrestrially influenced samples, suggesting that OPE concentrations were significantly influenced by air mass transport. Chlorinated OPEs were the dominant OPEs, accounting for 65.8-83.7% of the Sigma OPEs. Tris-(2-chloroethyl) phosphate (TCEP) was the predominant OPE compound in the samples (45.0 12.1%), followed by tris-(1-chloro-2-propyl) phosphates (TCPPs) (28.8 +/- 8.9%). Dry particle-bound deposition fluxes ranged from 8.2 to 27.8 ng m(-2) d(-1) for the Sigma OPEs. Moreover, the dry deposition input of the Sigma OPEs was estimated to be 4.98 ton y(-1) in 2013 in a vast area of northern SCS. About half of the input was found to relate to air masses originating from China. (C) 2015 Elsevier Ltd. All rights reserved

Selected current-use pesticides (CUPs) in coastal and offshore sediments of Bohai and Yellow seas

China is one of the largest producers, consumers, and traders for pesticides in the world. Currently, there are more than 600 pesticide-active substances registered in China, whereas few studies were conducted to improve our understanding of the occurrence and environmental impact of current-use pesticides (CUPs) in China's environment. In this work, 72 surface sediment samples were taken from the coastal and offshore of Bohai and Yellow seas and were analyzed for six CUPs (trifluralin, dacthal, quintozene, endosulfan, chlorpyrifos, and dicofol) and two metabolites (pentachloroanisole and endosulfan sulfate). Sediment samples were categorized as estuarine or near-shore sediments (Laizhou Bay, Taozi Bay, Sishili Bay, and Jiaozhou Bay) and offshore sediments. Trifluralin, alpha-endosulfan, endosulfan sulfate, chlorpyrifos, dicofol, and pentachloroanisole were detected in more than 60 % of the samples. Dicofol was the predominant compound with concentrations mostly higher than 100 pg/g dry weight (dw) with the highest concentration of 18,000 pg/g dw. Concentrations of other compounds were mainly below 100 pg/g dw. CUP levels were much lower than the sediment screening benchmark calculated. The highest levels of alpha-endosulfan, endosulfan sulfate, trifluralin, and chlorpyrifos existed at Laizhou Bay, whereas pentachloroanisole and dicofol had highest mean concentrations at Jiaozhou Bay. Generally, no correlation between pesticide concentrations and total organic carbon was observed either for offshore samples or for near-shore samples.China is one of the largest producers, consumers, and traders for pesticides in the world. Currently, there are more than 600 pesticide-active substances registered in China, whereas few studies were conducted to improve our understanding of the occurrence and environmental impact of current-use pesticides (CUPs) in China's environment. In this work, 72 surface sediment samples were taken from the coastal and offshore of Bohai and Yellow seas and were analyzed for six CUPs (trifluralin, dacthal, quintozene, endosulfan, chlorpyrifos, and dicofol) and two metabolites (pentachloroanisole and endosulfan sulfate). Sediment samples were categorized as estuarine or near-shore sediments (Laizhou Bay, Taozi Bay, Sishili Bay, and Jiaozhou Bay) and offshore sediments. Trifluralin, alpha-endosulfan, endosulfan sulfate, chlorpyrifos, dicofol, and pentachloroanisole were detected in more than 60 % of the samples. Dicofol was the predominant compound with concentrations mostly higher than 100 pg/g dry weight (dw) with the highest concentration of 18,000 pg/g dw. Concentrations of other compounds were mainly below 100 pg/g dw. CUP levels were much lower than the sediment screening benchmark calculated. The highest levels of alpha-endosulfan, endosulfan sulfate, trifluralin, and chlorpyrifos existed at Laizhou Bay, whereas pentachloroanisole and dicofol had highest mean concentrations at Jiaozhou Bay. Generally, no correlation between pesticide concentrations and total organic carbon was observed either for offshore samples or for near-shore samples

Influence of monsoon system on alpha-HCH fate in Asia: A model study from 1948 to 2008

The Chinese Gridded Pesticide Emission and Residue Model was applied to simulate long-term environmental fate of -hexachlorocyclohexane (HCH) in Asia spanning 1948 to 2008. The simulation identifies the southern Tibetan Plateau and the margin of the Asian monsoon regime from the northeast area of the Tibetan Plateau to the Northeast China as sink areas. This spatial pattern of sink distribution is closely related to the summer monsoon activities in Asia. Wet deposition associated with the summer monsoon (June to August) is responsible for at least half of the -HCH mass entering into the sink areas. After deposition, relatively low temperature and high soil organic matter in the sink areas are favorable for -HCH detention. Chinese and Indian sources are the major contributors to -HCH contamination over the monsoon margin and the Tibetan Plateau, driven by the East Asian summer monsoon and South Asian summer monsoon, respectively

Selected current-use and historic-use pesticides in air and seawater of the Bohai and Yellow Seas, China

Consumption of pesticides in China has increased rapidly in recent years; however, occurrence and fate of current-use pesticides (CUPs) in China coastal waters are poorly understood. Globally banned pesticides, so-called historic-use pesticides (HUPs), are still commonly observed in the environment. In this work, air and surface seawater samples taken from the Bohai and Yellow Seas in May 2012 were analyzed for CUPs including trifluralin, quintozene, chlorothalonil, dicofol, chlorpyrifos, and dacthal, as well as HUPs (hexachlorobenzene (HCB), hexachlorocyclohexanes (HCHs), and endosulfan). CUP profile in both air and seawater samples generally reflected their consumption patterns in China. HUPs in the air and seawater samples were in comparable levels as those of CUPs with high concentrations. alpha-Endosulfan, dicofol, and chlorothalonil showed strong net deposition likely resulting from their intensive use in recent years, while CUPs with low consumption amount (quintozene and dacthal) were close to equilibrium at most samplings sites. Another CUP with high usage amout (i.e., chlorpyrifos) underwent volatilization possibly due to its longer half-life in seawater than that in air. alpha-HCH and gamma-HCH were close to equilibrium in the Bohai Sea, but mainly underwent net deposition in the Yellow Sea. The net deposition of alpha-HCH could be attributed to polluted air pulses from the East China identified by air mass back trajectories. beta-HCH showed net volatilization in the Bohai Sea, which was driven by its relative enrichment in seawater. HCB either slightly favored net volatilization or was close to equilibrium in the Bohai and Yellow Seas.Consumption of pesticides in China has increased rapidly in recent years; however, occurrence and fate of current-use pesticides (CUPs) in China coastal waters are poorly understood. Globally banned pesticides, so-called historic-use pesticides (HUPs), are still commonly observed in the environment. In this work, air and surface seawater samples taken from the Bohai and Yellow Seas in May 2012 were analyzed for CUPs including trifluralin, quintozene, chlorothalonil, dicofol, chlorpyrifos, and dacthal, as well as HUPs (hexachlorobenzene (HCB), hexachlorocyclohexanes (HCHs), and endosulfan). CUP profile in both air and seawater samples generally reflected their consumption patterns in China. HUPs in the air and seawater samples were in comparable levels as those of CUPs with high concentrations. alpha-Endosulfan, dicofol, and chlorothalonil showed strong net deposition likely resulting from their intensive use in recent years, while CUPs with low consumption amount (quintozene and dacthal) were close to equilibrium at most samplings sites. Another CUP with high usage amout (i.e., chlorpyrifos) underwent volatilization possibly due to its longer half-life in seawater than that in air. alpha-HCH and gamma-HCH were close to equilibrium in the Bohai Sea, but mainly underwent net deposition in the Yellow Sea. The net deposition of alpha-HCH could be attributed to polluted air pulses from the East China identified by air mass back trajectories. beta-HCH showed net volatilization in the Bohai Sea, which was driven by its relative enrichment in seawater. HCB either slightly favored net volatilization or was close to equilibrium in the Bohai and Yellow Seas

Atmospheric polycyclic aromatic hydrocarbons in rural and urban areas of northern China

Air pollution in rural China has often been ignored, especially for the less developed west China. Atmospheric polycyclic aromatic hydrocarbons (PAHs) were measured monthly at 11 rural sites (5 rural villages and 6 rural fields) together with 7 urban stations in northern China between April 2010 and March 2011. PAH concentrations at rural village sites were similar to those in urban areas and significantly higher than those in rural fields, indicating severe contamination in rural villages. PAH concentrations in the west were similar to those in the more developed North China Plain, and higher than those along the coast. Such a geographical distribution is mainly caused by the differences in residential energy consumption and meteorological conditions, which can explain approximately 48% of the total variation in PAH concentrations. With heavy dependence on biofuel combustion for heating, seasonality in rural areas is more profound than that in urban areas. (C) 2014 Elsevier Ltd. All rights reserved.Air pollution in rural China has often been ignored, especially for the less developed west China. Atmospheric polycyclic aromatic hydrocarbons (PAHs) were measured monthly at 11 rural sites (5 rural villages and 6 rural fields) together with 7 urban stations in northern China between April 2010 and March 2011. PAH concentrations at rural village sites were similar to those in urban areas and significantly higher than those in rural fields, indicating severe contamination in rural villages. PAH concentrations in the west were similar to those in the more developed North China Plain, and higher than those along the coast. Such a geographical distribution is mainly caused by the differences in residential energy consumption and meteorological conditions, which can explain approximately 48% of the total variation in PAH concentrations. With heavy dependence on biofuel combustion for heating, seasonality in rural areas is more profound than that in urban areas. (C) 2014 Elsevier Ltd. All rights reserved