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Wu G.,South China Normal University | Zhai W.,South China Normal University | Sun F.,South China Normal University | Sun F.,Guangdong Higher Education Institutes | And 3 more authors.
Materials Research Bulletin | Year: 2012

Morphology-controlled Cu 2O microcrystalline particle films had been successfully electrodeposited on tin-doped indium oxide glass substrates in CuSO 4 solutions containing different amounts of polyethylene glycol (PEG) additives. With an increase of PEG, microcrystals gradually changed from irregular shapes to cubes, octahedrons, and spherical shapes. Sizes increasingly became smaller with an increase of PEG under the same deposition time. These films had been first used as recyclable photocatalysts and showed excellent and photocatalytic activities in photodegradation of methylene blue (MB) under sunlight. Activities were regularly varied relative to the morphologies of films controlled by the amount of PEG and could be further enhanced by adding a little amount of hydrogen peroxide in the MB solution. The method for controllable preparation of Cu 2O microcrystals with photocatalytic activities was simple and inexpensive. The as-prepared particle films could also be used in photodegradation of many other pollutants under sunlight. © 2012 Elsevier Ltd. All rights reserved. Source

Wang Q.,Jinan University | Wang Q.,Guangdong Higher Education Institutes | Feng X.,Chinese Academy of science | Yang Y.,Jinan University | And 2 more authors.
Environmental Toxicology and Chemistry | Year: 2011

Total mercury (THg) and methylmercury (MeHg) concentrations in four size fractions of plankton from three sampling stations in the Hg-contaminated and eutrophic Baihua Reservoir, Guizhou, China, were investigated for biomagnification and trophic transfer of Hg at different sites with various proximity to the major point sources of nutrients and metals. Total Hg concentrations in plankton of the various size fractions varied from 49 to 5,504ngg -1 and MeHg concentrations ranged from 3 to 101ngg -1. The percentage of Hg as MeHg varied from 0.16 to 70%. Total Hg and MeHg concentrations in plankton samples differed among the three sampling stations with different proximities from the major point sources. The plankton from the site closest to the dam contained the highest concentrations of MeHg. The successive increase of the ratios of MeHg to Hg from seston to macroplankton at all sites indicated that biomagnification is occurring along the plankton food web. However, biomagnification factors (BMF) for MeHg were low (1.5-2.0) between trophic levels. Concentrations of THg in seston decreased with an increase of chlorophyll concentrations, suggesting a significant dilution effect by the algae bloom for Hg. Eutrophication dilution may be a reason for lower MeHg accumulation by the four size classes of plankton in this Hg-contaminated reservoir. © 2011 SETAC. Source

Zhu S.Q.,Jinan University | Zhu S.Q.,Guangdong Higher Education Institutes | Wang S.E.,Jinan University | Chen Z.Q.,Jinan University | And 3 more authors.
Laser Physics | Year: 2012

This paper reported a passively Q-switched 532 nm green laser of LD pumped V cavity structure by using Nd:YAG/Cr 4+:YAG composite crystal and the type II phase matching KTP crystal. Under 19.4 W pump power, the average power of the laser pulse up to 1.83 W, with the pulse width of 93.2 ns and repetition frequency of 9.1 kHz. © Pleiades Publishing, Ltd., 2012. Source

Liao Y.H.,Guangdong Higher Education Institutes | Rao M.M.,Guangdong Higher Education Institutes | Li W.S.,Guangdong Higher Education Institutes | Yang L.T.,Guangdong Higher Education Institutes | And 3 more authors.
Journal of Membrane Science | Year: 2010

A new gel polymer electrolyte (GPE), fumed silica-doped poly(butyl methacrylate-styrene) (P(BMA-St))-based gel polymer electrolyte, was developed for lithium ion battery. The copolymer P(BMA-St) was synthesized by emulsion polymerization, the copolymer membranes doped with and without fumed silica were prepared through phase inversion, and the GPEs were obtained by immersing the membranes in 1 M LiPF6 solution. The structure and performances of the copolymer, the membranes and the GPEs were characterized by Fourier transform infrared spectroscopy (FTIR), gel permeation chromatography (GPC), scanning electron spectroscopy (SEM), thermogravimetric analysis (TGA), linear sweep voltammetry (LSV), chronoamperometry (CA), and electrochemical impedance spectroscopy (EIS). The copolymer P(BMA-St) is formed through the breaking of the double bond C{double bond, long}C in the monomers, butyl methacrylate and styrene. By doping 10 wt.% fumed silica in P(BMA-St) membrane, the properties of the membrane and the corresponding GPE were improved. The membrane doped with fumed silica is stable up to 355 °C and its pore size becomes more uniform and smaller; oxidative decomposition potential of the GPE doped with fumed silica is raised to 5.2 V (vs. Li/Li+) and its ionic conductivity is as high as 2.15 × 10-3 S cm-1 at ambient temperature. © 2010 Elsevier B.V. All rights reserved. Source

Yu J.,University of Sichuan | Yu J.,Guangdong Higher Education Institutes | Ho W.-T.,Commission on Environmental Consultation | Lu H.-M.,Guangdong Higher Education Institutes | Yang Y.-F.,Guangdong Higher Education Institutes
Environmental Monitoring and Assessment | Year: 2011

In order to understand the water quality and the genotoxicity of various surfaces in the Guangzhou section of the Pearl River during January to December of 2008, we investigated and studied the current water situation of the surface microlayer (SML) and the subsurface water (SSW) in Guanzhou section (Zhongda Dock and Yuzhu Dock) of the Pearl River by chemical analysis and biological monitoring method (Vicia faba micronucleus test). The results showed that during these months concentrations of the indexes of the two docks water such as total nitrogen (TN), total phosphorus (TP), chemical oxygen demand (COD) exceeded the national III level of surface water quality, and the indexes of SML were much higher than the ones of SSW (P< 0.05), and the exceeding rate of TN, TP of SML was 100%. According to the eutrophic evaluation standard, the water bodies of SML and SSW in the two docks were in a eutrophication during these months. The eutrophication and pollution of SML was more serious, and the highest index of eutrophication (E value) was up to 81.9, which also had obvious difference with COD and TP (P< 0.05). The water of SML in the two docks enriched to N, P, and chlorophyll a (Chl. a) seriously, and the enrichment factor of SML in Zhongda Dock to N, P, and Chl. a was 0.71 ∼ 2.78, 0.98 ∼ 1.18, and 0.49 ∼ 13.99, respectively, and the one in the Yuzhu Dock was 1.09 ∼ 1.52, 1 ∼ 1.14, and 0.72 ∼ 4.07, respectively. Through inspecting the water genotoxicity of various layers by V. faba micronucleus test, we could know that the average annual MCN‰ of SML and SSW in the two docks was 6.09‰, 5.53‰, 5.57‰, and 5.249‰, respectively. In general, the above value of SML was a little higher than the one of SSW, but there was not a remarkable difference (P> 0.05). This research shows that the water quality in a medium to heavy eutrophication in the Guangzhou section of Pearl River belongs to national III ∼ IV level, and SML has the capability of enrichment to the pollutants such as N and P and induces the increase of micronucleus rate of V. faba tip cell. The study also indicates that there may be genotoxicity matters such as N, P in water body. © 2010 Springer Science+Business Media B.V. Source

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