固态聚苯胺电致变色器件的制备和性能

采用CeO2-TiO2复合物薄膜作为聚苯胺电致变色器件的对电极,选用聚合物固态电解质(PE:PMMA-PC-EC-L iC lO4),构筑了新型双层结构(Dual-type)聚苯胺(PANI)固态电致变色(EC)器件.用电化学现场紫外-可见光谱法表征了该EC器件(ITO|PANI||PE||CeO2-TiO2|ITO)的电致变色性能,并与单层结构(S ingle-type)EC器件(ITO|PANI||PE||ITO)进行了比较.研究结果表明,双层结构EC器件比单层结构EC器件的电致变色性能好,如响应速度快,循环寿命长.同时,考察了电解质组分对聚苯胺电致变色稳定性的影响.EC器件(ITO|PANI||PE||CeO2-TiO2|ITO)的颜色呈现由透明的黄色(-1.5 V,PANIvs.CeO2-TiO2)到蓝色(1.0 V)的可逆变化,在700 nm处的透射率由42.19%变到13.35%,经过150个循环,其透射率差仍保持不变,着色效率为152.1 cm2/C

Impact of Different Land Use Modes on Nutrients of Sediments from Mangrove Wetlands of China

以广西、广东、海南等地代表性红树林湿地为对象,研究红树林湿地利用方式的改变对沉积物有机碳、总硫、总氮和总磷等营养元素的含量变化和影响,结果表明:1)广东和海南红树林区总氮和总磷变化相似,均为:沉积物>农田>鱼塘>光滩,广西大冠沙稍有不同,光滩的氮磷含量最低;有机碳和总硫含量各地稍有差异,但是红树林沉积物中的有机碳,总硫含量普遍高于当地光滩、鱼塘和农田土壤,并且以光滩的土壤营养元素含量最低。2)根据广东、广西、海南主要红树林区推算全国红树林区土地利用方式的改变后土壤有机碳、总硫、总氮、总磷的损失量分别为3.05x1012 g、2.68x1011 g、2.94x1012 g和0.377x1011 g。说明土地利用与土地覆被的变化加剧了土壤有机碳、硫、氮磷的流失,导致原红树林区土壤逐渐贫瘠。This study aims at evaluating impacts of mangrove wetland-use on the levels of organic carbon,total surfer,total nitrogen and total phosphorus in sediments from major mangrove wetland ecosystems in Guangxi Autonomous Region,Guangdong and Hainan Island,China.Our results show that: 1) both Guangdong and Hainan displayed the same pattern for total nitrogen and total phosphorus,decreasing in the order of sediment> farmland> pond> mudflat;within a slightly different order,the lowest levels for total nitrogen and total phosphorus were also observed in the mudflat of Guangxi Daguansha mangrove wetland.As to the concentrations of organic carbon and total surfer,although a slight difference was detected,all the three districts exhibited greater values in mangrove sediments,with the levels of mudflat being the lowest;2) based on loss amounts from Guangdong,Guangxi and Hainan,we further calculated the nationwide loss amounts of organic carbon,total sulfur,nitrogen and phosphorus(3.05×1012 g,2.68×1011 g,2.94×1012 g and 0.377×1011 g,respectively) and it can be concluded that changes in land use mode escalated the loss of organic carbon,surfer,nitrogen and phosphorus in soils,thus leading to gradual soil erosion in mangrove wetlands.国家自然科学基金项目(41176090;40676064);海洋公益性行业科研专项经费项目(200805063-3);东华理工大学核资源与环境教育部重点实验室(101102)联合资

Preparation and Performance of Solid-state Electrochromic Devices Based on Polyaniline

In this paper, by polymeric electrolyte (PMMA-PC-EC-LiClO4), we introduced CeO2-TiO2 Composite as the complementary electrode of a new solid-state dual-type polyaniline electrochromic device(ECD). The electrochromic performance of the dual-type ECD was characterized using lit situ UV-Vis spectroscopy. Compared to single-type ECD (ITO | PANI | | PE | | ITO), the dual-type ECD showed better electrochromic performance such as less response time, longer cyclic lifetime. Also, the composition of the electrolyte was found to influence the cyclic stability of PANI. The optimized dual-type ECD exhibited reversible electrochromic behavior from yellow at bleached state (-1.5 V) to blue at colored state (1.0 V PANI vs. CeO2-TiO2) with good cyclic stability. The transmittance of the ECD at 700 nm changed from 42.19% to 13.35% with a coloration efficiency of 152.1 cm(2)/C