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Factors influencing the photodegradation of Nnitrosodimethylamine in drinking water

Frontiers of environmental Science & engineering 2009年第1期3卷 91-97页

作者： Bingbing XU Zhonglin CHEN Fei QI Jimin SHEN Fengchang WU State Key Laboratory of Urban Water Resource and Environment Harbin Institute of TechnologyHarbin 150090China State Environmental Protection Key Laboratory for Lake Pollution Control Chinese Research Academy of Environmental SciencesBeijing 100012China College of Environmental Science and Engineering Beijing Forestry UniversityBeijing 100083China

In order to provide basic data for practical application,photodegradation experiment of Nnitrosodimethylamine(NDMA)in aqueous solution was carried out with a low-pressure Hg *** of the initial concentration of NDMA,solution pH,dissolved oxygen,and the presence of humic acid on NDMA photodegradation were *** at various initial concentrations selected in this study was almost completely photodegraded by UV irradiation within 20 min,except that at 1.07 mmol/L,NDMA could be photodegraded almost completely in the acidic and neutral solutions,while the removal efficiency decreased remarkably in the alkaline *** oxygen enhanced the NDMA photodegradation,and the presence of humic acid inhibited the degradation of *** on the initial concentration of NDMA,NDMA photodegradation by UV obeyed the pseudo-first-order ***,nitrite,and nitrate were detected as the photodegradation products of NDMA.^(1)O_(2) was found to be the reactive oxygen species present in the NDMA photodegradation process by UV,based on the inhibiting experiments using tert-butanol and sodium azide.

关键词： N-nitrosodimethylamine(NDMA) ultraviolet irradiation degradation kinetic dimethylamine photodegradation product

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Synthesis and application of zircoaluminate coupling agent as surface modifier of nano-sized titanium dioxide

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Huanan Ligong Daxue Xuebao/Journal of South China University of technology (Natural Science) 2009年第6期37卷 7-12页

作者： Li, Bin Li, You-Ming Yang, Wen-Liang National Engineering Research Center of Papermaking and Pollution Control South China University of Technology Guangzhou 510640 China

Zircoaluminate coupling agent with carboxy groups was synthesized, with polyaluminium chloride, zirconium oxychloride and adipic acid, etc., as the materials. The product and the nano-sized TiO2 before and after the surface modification were then characterized by means of FT-IR, TG-DTG, XRD, TEM and by measuring the size distribution. It is found that one carboxy group in adipic acid forms a complex bridge between the aluminum and the zirconium centers, while the other remains unchanged as the functional group of the coupling agent;and that the proportion of inorganic parts in the coupling agent is up to 71%. Moreover, as for the nano-sized TiO2 surface-modified with the coupling agent, there exists a chemical adsorption of the coupling agent on TiO2 surface, which has no effect on the crystalline form of nano-sized TiO2, and, the dispersion of the modified nano-sized TiO2 in water improves remarkably.

关键词： Surface treatment

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Effect of an integrated mangrove-aquaculture system on aquacultural health

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Frontiers in Biology 2009年第4期4卷 579-584页

作者： Yisheng PENG Xulin LI Kalan WU Yougui PENG Guizhu CHEN School of Environmental Science and Engineering Sun Yat-Sen University/Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation TechnologyGuangzhou 510275China Research Center of Wetland Science Sun Yat-Sen UniversityGuangzhou 510275China College of Forestry South China Agricultural UniversityGuangzhou 510642China

Mangroves are unique intertidal halophyte formations growing in sheltered tropical and subtropical coastal *** to the increasing population and economic development,mangroves have faced degrada-tion and loss,which has been mainly caused by land conversion into aquaculture ponds in *** the past several decades,the rapid growth of aquaculture has induced water *** mangroves for effluent treatment from coastal aquaculture ponds could be a suitable approach for wastewater treatment and healthy aquaculture *** Integrated Mangrove-Aquaculture System(IMAS)was established to test whether the idea of a mangrove in situ treatment for aquaculture wastewater is *** monocultures of three mangroves,Sonneratia caseolaris,Kandelia obo-vata,and Aegiceras corniculatum were established with area proportions of 45%,30%,or 15%,*** control pond without mangroves was also set *** results indicated that the mangroves had different toler-abilities to long-term *** aquaculture ponds had different fishery yields,considering the mangrove species and area *** water quality of most of the experimental ponds was better than the control pond,except for the planted *** is concluded that mangroves can reduce the concentration of dissolved inorganic nitrogen and phosphate,buffer the pH value and increase the concertration of dissolved oxygen in aqua-culture water bodies *** is suggested to use 15%of the Aegiceras corniculatum area to conduct in situ purification of aquaculture wastewater and to enhance aquaculture production.

关键词： water quality water treatment sustainable use mangroves aquaculture

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Analysis of thermal stress response in asphalt overlay

Analysis of thermal stress response in asphalt overlay

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9th International Conference of Chinese Transportation Professionals, ICCTP 2009: Critical Issues in Transportation System Planning, Development, and Management

作者： Wensheng, Xu Wei, Tian Hui, Luo Wuhan Huazhong Keda Civil Engineering Inspection Center Hubei Key Laboratory of Control Structure School of Civil Engineering and Mechanics 430074 Wuhan Hubei China Wuhan Harbour Engineering Design and Research Institute Key Laboratory of Bridge and Tunnel Technology of the Ministry of Communications 430074 Wuhan Hubei China School of Civil Engineering and Mechanics Huazhong University of Science and Technology 430074 Wuhan Hubei China

ISBN: (纸本)9780784410646

The thermal stress response in asphalt overlay under different cooling conditions was analyzed considering thermal-viscoelasticity of asphalt mixture. The influence of cooling speed, initial temperature, cooling range, pavement thickness and base modulus on temperature stress were represented. The results indicate that, the cumulated thermal stress in asphalt overlay is small at high temperature;initial temperature and cooling speed distinctly affect thermal stress in asphalt overlay;reflective cracks occur in thinner asphalt overlay more easily, while top-down cracks happen in thicker asphalt overlay more easily;and too large base modulus is unsuitable to controlling thermal crack in asphalt overlay. © 2009 ASCE.

关键词： Thermal stress

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Matrix-bound phosphine in Ny-Alesund Area of Arctic

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High technology Letters 2009年第3期15卷 331-336页

作者：封颖 Wang Qiang Yao Ziwei Geng Jinju Institute of Science and Technology Information of China Beijing 100038P. R. China College of Environmental Science and Engineering Peking University Beijing 100871 P. R. China National Marine Environmental Monitoring Center Dalian 116023 P. R. China State Key Laboratory of Pollution Control and Resource Reuse School of Environment Nanjing University Nanjing 210093 P. R. China

Phosphine, a ubiquitous trace gas in the atmosphere, acts as a carrier of gasous phosphorus in the biogeochemical cycle. The research of phosphine will show new light on the mechanisms of how the phos- phorus supplement influence the biogeochemical cycle and global wanning. In this paper, we detect the phosphine in Arctic Pole area for the first time. The result shows that matrix-bound phosphine（MBP） ex- ists in all the samplings. Phosphine distributions varied with different environmental origins. Average phosphine concentrations in tundra soil, lake sediments, sea sediments, seabird-droppings and deer guanos were 14.17ng/kg dry, 35.44 kg dry, 67.20 kg dry, 32.9 ng/kg dry, and 25.52 ng/kg dry re- spectively. Correlation analysis shows that there is an obviously positive correlation between Porg and MBP. It could be concluded that anaerobic decomposition of Porg and the mechano-chemistry action of the rock probably are the possible reasons explaining the mechanism of MBP production in Arctic Pole area.

关键词： matrix-bound phosphine （MBP） Arctic Pole area distribution Porg rock

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Routing protocol for wireless sensor networks in home automation 8th

Routing protocol for wireless sensor networks in home automa...

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8th IFAC Conference on Fieldbuses and Networks in Industrial and Embedded Systems, FeT 2009

作者： Li, Xiao Hui Xu, Hong Qin Hong, Seung Ho Wang, Zhi Piao, Xiang Fan Engineering Research Center of Metallurgical Automation and Measurement Technology Ministry of Education Wuhan University of Science and Technology Wuhan Hubei430081 China State Key Laboratory of Industrial Control Technology Zhejiang University Hangzhou310027 China Department of Electronics Information and System Engineering Hanyang University 425-791 Korea Republic of Department of Electronic Information Engineering College of Science and Engineering Yanbian University Yanji133002 China

ISBN: (纸本)9781617825583

Home automation systems based on wireless sensor/actuator networks are characterized by diversity of node power sources, limited computational power, and mobility. We propose a routing protocol that fully uses the location of static nodes to limit the search for a route to a small zone based on the analysis of characteristics and requirements. The calculation of two different kinds of zone and the route discovery procedure are described in this paper. According to the environment of home automation, we compared the performance of our routing protocols with the ad-hoc on-demand distance-vector protocol using simulation and gave suggestions for zone selection. Simulation results showed that our routing protocol dramatically reduced the routing overhead and increased the reliability.

关键词： Routing protocols

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Spatial Distribution of Land Cover and Vegetation Activity along Topographic Gradient in an Arid River Valley, SW China

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Journal of Mountain Science 2009年第3期6卷 274-285页

作者： LIU Wen XU Xianli LUO Jiancheng SHEN Zhanfeng ZHONG Qiuhai Department of Automatic Control School of Automation Beijing Institute of Technology Beijing 100081 China State Key Laboratory of Urban and Regional Ecology Research Center for Eco-Environmental Sciences Chinese Academy of Sciences Beijing 100085 China Institute of Remote Sensing Applications Chinese Academy of Sciences Beijing 100101 China Centre for Hydrology Micrometeorology and Climate Change Department of Civil and Environmental Engineering University College Cork Cork Ireland

Anthropogenic activities have become more and more important in characterizing the landscape, but their impacts are still restricted by natural environments. This paper discusses the interactions of anthropogenic activity, vegetation activity and topography through describing the spatial distribution of land cover and vegetation activity (represented by Normalized Difference Vegetation Index, NDVI) along topographic gradient in a mountainous area of southwestern China. Our results indicate that the existing landscape pattern is controlled by anthropogenic activities as well as topographic factors. Intensive anthropogenic activities mainly occur in areas with relatively low elevation, gentle and concave slopes, as these areas are easy and convenient to attain for human. Because of the destruction by human, some land cover types (mainly grassland and shrub) are only found in relatively harsher environments. This study also finds that topographic wetness index (W) used in other places only reflects runoff generation capacity, but not indicate the real spatial pattern of soil water content in this area. The relationships between NDVI and W, and NDVI and length slope factor (LSF) show that runoff and erosion have complex effects on vegetation activity. Greater values of W and LSF will lead to stronger capacity to produce runoff and transport sediment, and thereby increase soil water content and soil deposition, whereas beyond a certain threshold runoff and erosion are so strong that they would destruct vegetation growth. This study provides information needed to successfully restore native vegetation, improve land management, and promote sustainable development in mountainous areas, especially for developing regions.

关键词： Vertical distribution of land cover Anthropogenic activity Vegetation activity environmental variability China

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Characterization and flocculation treatment of organic substances present in landfill leachate

Characterization and flocculation treatment of organic subst...

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The 3rd International Conference on Bioinformatics and Biomedical engineering(iCBBE 2009)(第三届生物信息与生物医学工程国际会议)

作者： Yimin Sang Cunzhen Liang Jiaqing Chen Fasheng Li Qingbao Gu Department of Environmental Engineering Beijing Institute of Petrochemical Technology Beijing China Department of Soil Pollution Control Chinese Research Academy of Environmental Sciences Beijing Chin

Organic pollutants present in landfill leachate are characterized and treated with a novel inorganic polymer flocculants, poly-ferric(Ⅲ)-magnesium(Ⅱ)-aluminum(Ⅲ)-sulfate (PFMAS). First, the removals of COD, BOD5 and color are determined with optimum conditions by jar-test. Then, organic contaminants in the leachate before and after treatment are identified by gas chromatography coupled with mass spectrometry (GC-MS). The results indicate that the removals of color, COD, and BOD5 by coagulation with PFAMS can reach 89％, 68％, and 58％, respectively, which greatly reduces the extent of pollution and improves its appearance. About 85 kinds of organic species are identified in the leachate and some of them belong to the Black List of environmental preferred controlled pollutants considered by the USA and China environmental Protection Agengcy. Particularly, the typical pollutants are quantitatively analyzed. The alkyl, alkene, ester, ketone, aldehyde, acyclic acid, acyclic alcohol and acyclic amine species are removed greatly (about 60-100％), and some are removed completely, while species with a benzene ring, such as aromatic acids, aromatic alcohols, aromatic amine aromatic hydrocarbons, hydroxybenzenes, and pyridines, are partially removed (about 25-70％).

关键词： Characterization GC-MS Inorganic polymer flocculants Landfill leachate Organic substance Treatment

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Accurate tracking control of a linear fast tool servo unit for noncircular cutting

Accurate tracking control of a linear fast tool servo unit f...

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IEEE International Conference on Mechatronics and Automation

作者： Xuefeng Chang Youping Chen Wu Ai Zude Zhou National Numerical Control System Engineering Research Center Huazhong University of Science and Technology Wuhan Hubei China

In this paper, an accurate position tracking control scheme is proposed for a moving-coil-type linear DC motor driven fast tool servo unit for noncircular cutting application. A sliding mode tracking controller is designed to ensure the system has a fast tracking characteristic to the position command. Moreover a disturbance observer is used to estimate and compensate exogenous disturbance to improve robustness and stability of the fast tool servo unit. Because the reference input is approximately periodic in noncircular cutting process. Therefore, the periodic error can he further reduced by augmenting an iterative learning controller to the existing sliding mode controller for repetitive position tracking. The experimental results of noncircular cutting adopting the proposed control method, including tracking performance and robustness of the system, are much improved.

关键词： Servomechanisms Sliding mode control control systems Error correction Robust control Three-term control DC motors Robust stability Machining Fuzzy control

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A novel seam measuring method of complex tight butt joint for laser welding

A novel seam measuring method of complex tight butt joint fo...

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IEEE International Conference on Mechatronics and Automation

作者： Jiayong Wu Pingjiang Wang Xingdou Fu Biao Liu Jihong Chen National Numerical Control System Engineering Research Center Huazhong University of Science and Technology Wuhan Hubei China

Seam measuring of complex tight butt joint without misalignment for laser welding is a challenging problem. The allowable seam gap width and misalignment in laser welding process are less than 0.1 mm for thin sheet around 2 mm thickness. Current measuring methods or sensors can not stably and accurately extract 3D seam position and seam gap width, due to narrow seam gap and too little misalignment of the butt joint. Furthermore, almost all sensors can not provide seam surface normal vector directly along with seam position and seam gap width. A novel seam measuring method, integrating the 2D machine vision and 3D structured light vision techniques, is proposed. By projecting a unique pattern of three structured light stripes onto the seam surface, 3D seam position, seam gap width and seam surface normal vector can be accurately acquired from a single image, using the 2D/3D vision information fusion approach. Experimental results demonstrate that the proposed seam measuring method is capable of extracting the integrated seam features of tight butt joint without misalignment stably and accurately.

关键词： Welding Current measurement Laser fusion Position measurement Focusing Surface fitting Computer vision Laser beams Surface emitting lasers Machine vision

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