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Secondary aerosol formation and oxidation capacity in photooxidation in the presence of Al_2O_3 seed particles and SO_2

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Science China chemistry 2015年第9期58卷 1426-1434页

作者： Biwu Chu Tengyu Liu Xiao Zhang Yongchun Liu Qingxin Ma Jinzhu Ma Hong He Xinming Wang Junhua Li Jiming Hao State key Joint laboratory of Environment Simulation and Pollution Control Research Center for Eco-Environmental Sciences Chinese Academy of Sciences State key laboratory of Organic Geochemistry Guangzhou Institute of Geochemistry Chinese Academy of Sciences School of Environment Tsinghua University Nanjing University of Information Science & Technology

To investigate the sensitivity of secondary aerosol formation and oxidation capacity to NOx in homogeneous and heterogeneous reactions, a series of irradiated toluene/NOx/air and ?-pinene/NOx/air experiments were conducted in smog chambers in the absence or presence of Al2O3 seed particles. Various concentrations of NOx and volatile organic compounds(VOCs) were designed to simulate secondary aerosol formation under different scenarios for NOx. Under "VOC-limited" conditions, the increasing NOx concentration suppressed secondary aerosol formation, while the increasing toluene concentration not only contributed to the increase in secondary aerosol formation, but also led to the elevated oxidation degree for the organic aerosol. Sulfate formation was suppressed with the increasing NOx due to a decreased oxidation capacity of the photooxidation system. Secondary organic aerosol(SOA) formation also decreased with the presence of high concentration of NOx, because organo-peroxy radicals(RO2) react with NOx instead of with peroxy radicals(RO2 or HO2), resulting in the formation of volatile organic products. The increasing concentration of NOx enhanced the formation of sulfate, nitrate and SOA under "NOx-limited" conditions, in which the heterogeneous reactions played an important role. In the presence of Al2O3 seed particles, a synergetic promoting effect of mineral dust and NOx on secondary aerosol formation in heterogeneous reactions was observed in the photooxidation. This synergetic effect strengthened the positive relationship between NOx and secondary aerosol formation under "NOx-limited" conditions but weakened or even overturned the negative relationship between NOx and secondary aerosol formation under "VOC-limited" conditions. Sensitivity of secondary aerosol formation to NOx seemed different in homogeneous and heterogeneous reactions, and should be both taken into account in the sensitivity study. The sensitivity of secondary aerosol formation to NOx was further

关键词： secondary aerosol oxidation capacity synergetic promoting effect Al2O3 seed particles sensitivity

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Progress in the Supramolecular Architecture-directed Synthesis of Perfect Ladder Polysiloxanes

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复旦学报（自然科学版） 2007年第5期46卷 642-,646页

作者： C C Han Center for Molecular Science State Key Lab of Polymer Physics & Chemistry Institute of Chemistry Chinese Academy of Sciences

1 Introduction Ladder polysiloxanes (LPSs) including organo-bridged ladder polyorganosiloxanes (R-OLPSs, R is side group) and ladder polyorganosilsesquioxanes (R-LPSQs) have intrigued polymer chemists for about 50 years due to their excellent resistance to all kinds of degradations. However, their synthesis has been a great challenge to polymer chemists. Here, we describe a new approach based on supramolecular concerted interactions as follows.2 Results2.1 Synthesis of Perfect R-OLPSsA series of real ...

关键词： supramolecular architecture organo-bridged ladder polyorganosiloxanes (R-OLPSs) ladder polyorganosilsesquioxanes (R-LPSQs)

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Mechanical Properties of Silica Aerogels Prepared from a Mixture of TEOS and organo-alkoxysilanes of Type R_1SiX_3

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Journal of Wuhan University of Technology(Materials Science) 2014年第1期29卷 201-207页

作者：杨海龙孔祥明 ZHANG Yanrong WU Chunchao CAO Enxiang Department of Civil Engineering Key Laboratory of Civil Engineering Safety and Durability of China Education Ministry Tsinghua University

Silica aerogels were prepared from a mixture of tetraethylorthosilicate and organo- alkoxysilanes. The effects of organo-alkoxysilanes on the mechanical properties of the silica aerogels were studied. The flexibility of silica aerogels was significantly improved by incorporation of organo-alkoxysilanes. When MTES and TEOS were combined as precursors of silica areogels, with the increased amount of MTES, the apparent elastic modulus and apparent compressive strength monotonously rose. At the same organo- alkoxysilanes to TEOS ratio, the size of alkyl groups of the organo-alkoxysilanes had little effect on the mechanical properties. In series of MTES and TEOS, the lowest elastic modulus of silica skeleton and the highest compressive strength of silica skeleton were observed at MTES to TEOS ratio of around 50：50. At a certain organo-alkoxysilanes to TEOS ratio, the elastic modulus of silica skeleton increased and the compressive strength of silica skeleton decreased with the size increase of the alkvl grouns.

关键词： silica aerogels mechanical properties organo-alkoxysilanes silica skeleton flexibility sol-gel

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Synthesis and Characterization of PE-g-MA/MgAl-LDH Exfoliation Nanocomposite via Solution Intercalation

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Chinese Journal of chemistry 2003年第8期21卷 998-1000页

作者：陈伟瞿保钧 State key laboratory of Fire Science and Department of Polymer Science and Engineering University of Science and Technology of China Hefei

An organo modified MgAl layered double hydroxide (OMgAl LDH) was successfully exfoliated in the xylene solution of polyethylene grafted maleic anhydride (PE g MA) under refluxing condition. A PE g MA/MgAl LDH exfoliation nano composite was formed after the precipitation of PE g MA from the dispersion system. The structure and thermal property of the PE g MA/MgAl LDH exfoliation nanocomposite were characterized by X ray diffraction (XRD), transmission electron microscopy (TEM), and thermogravimetry analysis (TGA). The disappearance of d 001 XRD peak of OMgAl LDH at 2 θ =3 2° suggests that the MgAl hydroxide sheets are exfoliated in the nanocomposite. The TEM image shows that the MgAl hydroxide sheets of less than 70 nm in length or width are exfoliated and dispersed disorderly in PE g MA matrix. TGA profiles indicate that the PE g MA/MgAl LDH nanocomposite with 5 wt% OMgAl LDH loading shows a faster charring process in temperature range from 210 to 390 ℃ and a greater thermal stability beyond 390 ℃ than PE g MA does. The decomposition temperature of the nanocomposite is 25 ℃ higher than that of PE g MA as measured at 50% weight loss. The PE g MA/MgAl LDH nanocomposite is promising for application of flame retardant polymeric materials.

关键词： polymer/layered double hydroxide nanocomposites exfoliation thermal stability

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Fractionation of residual Al in natural water treatment from reservoir with poly-aluminum-silicate-chloride (PASiC): Effect of OH/Al, Si/Al molar ratios and initial pH

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Journal of Environmental Sciences 2012年第11期24卷 1908-1916页

作者： Zhonglian Yang Baoyu Gao Yan Wang Yaqin Zhao Qinyan Yue Shandong key laboratory of Water Pollution Control and Resource Reuse School of Environmental Science and EngineeringShandong UniversityJi'nan 250100China

An aluminum fractionation study was conducted for a surface reservoir water treatment to understand the performance of poly- aluminum-silicate-chloride （PASiC） in terms of the residual A1 fractions as a function of initial pH. The coagulation performance expressed as turbidity and organic matter removal was established as supporting data. Some extra data were evaluated in terms of the residual A1 ratio of the composite PASiC coagulant. The main residual A1 sources were the A1 fractions derived from the use of PASiC. The turbidity and organic matter removal ability was optimal at initial pH 6.00-7.00, while the concentrations of various residual A1 species and the residual A1 ratio of PASiC were minimal at an initial pH range of 7.00-8.00. Under the conditions of OH/AI molar ratio = 2.00 and Si/A1 molar ratio = 0.05, PASiC had superior coagulation performance and comparatively low residual A1 concentrations. The A1 fraction in the composite PASiC coagulant seldom remained under such conditions. Experimental data also indicated that the suspended （filterable） AI fraction was the dominant species, and organic-bound or organo-A1 complex A1 was considered to be the major species of dissolved A1 in water treated by PASiC coagulation. Additionally, the dissolved inorganic monomeric A1 species dominated the dissolved monomeric A1 fraction.

关键词： coagulation performance OH/A1 and Si/AI molar ratio poly-aluminum-silicate-chloride (PAniC) resi0ual AI speclataon residual A1 ratio

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Synthesis,Crystal Structure and Thermal Stability of Homopolytungstate Supporting Nickel(Ⅱ) Coordination Fragments

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Chemical Research in Chinese Universities 2007年第4期23卷 391-394页

作者： LIU Kun MENG Fan-xiaI MA Feng-xia CHEN Ya-guang key laboratory of Polyoxometalates Science of Ministry of Education College of Chemistry Northeast Normal University Changchun 130024 P. R. China Basic Science Department Jilin Agricultural Science and Technology College Jilin 132101 P. R. China

The orsano-inorganic hybrid compound [ Ni（phen）3] [ （H2W12O40） { Ni（phen）2H2O} { Ni（trien） } ]·2H2O was synthesized from Na2 WO4·2H2O, NiSO4·6H2O, CH3COOK, triethylenetetramine and 1,10-phenanthroline in water by the hydrothermal reaction, and characterized by IR, X-ray single crystal diffraction, and TG-DTA analysis. This compound crystallized in the monoclinic system, space group P2 （1）/n, with lattice constants： a =1.80998 （6） nm, b =2.36504（8） nm, c =2.29199（7） nm,β= 110.2220（10）°, V=9.2065（5） nm, Z=4. Final R indices R1=0.0532. ωR2=0.1295. The compound is decomposed at 593℃.

关键词： Isopolytungstate Nickel complex Crystal structure organo-inorganic hybrid Supramolecular architecture Thermal stability

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Exposure-response of Cr(Ⅲ)-organic complexes to Saccharomyces cerevisiae

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Frontiers of Environmental Science & Engineering 2010年第2期4卷 196-202页

作者： Nivedita CHATTERJEE Zejiao LUO key laboratory of Biogeology and Environmental Geology Ministry of Education(BGEG)School of Environmental StudiesChina University of GeosciencesWuhan 430074China

Hexavalent chromium[Cr(VI)]bioreduction produces soluble Cr(Ⅲ)-organic *** Cr(Ⅲ)-organic complexes are relatively stable once they are formed,and no data about their toxicity were ***,this study aims to investigate the bioavailability and toxicity of the soluble Cr(Ⅲ)-organic *** cerevisiae L^(-1)wild type yeast strain was chosen as the model organism and Cr(Ⅲ)-citrate was selected as the representative compound of the Cr(Ⅲ)-organic *** short-term chronic aquatic toxicity tests of the Cr(Ⅲ)-citrate was explored by measuring growth inhibition,direct viable cell count,dry biomass,biosorption,and the amount of CO_(2)***(Ⅲ)-citrate exerted a toxicity of 51 mg/L with an EC_(50),which was calculated from the percent growth *** toxicity data would be helpful to define the toxic potential of the organo-chromium-Ⅲcompounds in the environment.

关键词： Cr(Ⅲ)-organic complexes Saccharomyces cerevisiae toxicity EC_(50) bioavailability

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Soil concentrations and soil-air exchange of organochlorine pesticides along the Aba profile, east of the Tibetan Plateau, western China

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Frontiers of Earth Science 2013年第4期7卷 395-405页

作者： Hongxia LIU Shihua QI Dan YANG Ying HU Feng LI Jia LIU Xinli XING State key laboratory of Biogeology and Environmental Geology School of Environmental Studies China University of Geosciences Wuhan 430074 China Hubei key laboratory of Mine Environmental Pollution Control & Remediation School of Environmental Science and Engineering Hubei Polytechnic University Huangshi 435003 China Faculty of Engineering China University of Geosciences Wuhan 430074 China

Mianzhu--Aba profile, east of the Tibetan Plateau, was selected to study the occurrence of organo- chlorine pesticides （OCPs） along an altitudinal gradient. Dichlorodiphenyltrichloroethanes （DDTs）, hexachlorocy- clohexanes （HCHs） and Aldrin, Dieldrin and Endrin （Drins） in surface soils were detected in winter （March） and summer （July）. Soil concentrations （ng.g-1, dw） in winter and summer ranged as follws： DDTs, 0.37-179.16 and 0.32-42.57; HCHs, 0.14-10.76 and 0.55-32.71; Drins, N.D-3.99 and 0.02-6.93, respectively. Main soil OCPs were p,p＇-DDT, p,p＇-DDE, fl-HCH and Drins, among which Drins were rarely reported in current literature of the Tibetan Plateau. Higher OCP concentra- tions in the profile were attributed close to the agricultural fields of the Sichuan Basin, current lindane and non- dicofol DDTs inputs, and also long-range atmospheric transport from abroad. Soil OCP concentrations underwent obvious seasonal variation, with higher DDTs in winter and higher HCHs and Drins in summer. It may be caused by climatic conditions, summer monsoon type, and physico-chemical properties of such contaminants. Though ＂rest＂ phenomenon occurred in some sampling sites, HCHs and Drins showed an increasing trend with increasing altitude, while DDTs showed an evident decrease with increasing altitude. The altitudinal distribu- tions of OCPs were all consistent with previous findings in other mountainous regions. A primary fugacity analysis on OCPs soil-air exchange indicated that the profile may be secondary sources for HCHs and Endrin. As with Aldrin,Dieldrin, and DDTs, the profile may be both secondary sources and sinks.

关键词： organochlorine pesticides (OCPs) seasonal variation altitudinal pattern soil-air exchange Mian-zhu--Aba profile east of the Tibetan Plateau

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Metal and organo-catalysed asymmetric hydroaminomethylation of styrenes

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催化学报 2015年第1期36卷 106-112页

作者： Barbara Villa-Marcos Jianliang Xiao Department of chemistry University of Liverpool

A new protocol that enables asymmetric hydroaminomethylation of styrenes to afford chiral amines has been developed. Catalysed by an Rh-phosphine species and a chiral phosphoric acid, styrenes are converted into β-chiral amines with good enantioselectivities under syngas in the presence of an amine and Hantzsch ester. The reaction involves two key steps, hydroformylation and reductive amination, with the former catalysed by the Rh species whilst the latter by the phosphoric acid.

关键词：苯乙烯不对称有机催化金属对映选择性加氢甲酰化手性胺酸催化

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Evaluation of Layered Inorganic Nano-powder Modified Bitumen

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武汉理工大学学报 2010年第17期32卷 51-54页

作者： HAN J WU S P CHEN M Y YU M key laboratory of Silicate Materials Science and Engineering Wuhan University of TechnologyWuhan 430070China

Thermal oxidative and aging as an inevitable process in the practical application of road asphalt has great effect on the properties of asphalt. In this paper,the influences of short-term thermal oxidative ageing and ultraviolet radiation(UV) aging on the dynamic viscosity,penetration,softening point and rheological properties of two kinds of layered inorganic nano-powder including organo-modified montmorillonite (OMMT) and nanometer brucite (Mg(OH)2) modified asphalts were studied respectively. The rheological properties of these binders have been determined using a dynamic shear rheometer (DSR) through temperatures sweep *** rheological and physical analysis showed the two major influences of ageing on the properties for two kinds of layered inorganic nano-powder modified bitumens. On one hand,ageing decreased the viscous behaviors of modified binders,on the other hand,ageing improved the elastic behaviors of modified binders. The performances of binders after aging depended on the combined effect between the modifier and the bitumen. Both the two modifiers resisted the aging of bitumens and the effect of OMMT was better.

关键词： ageing evaluation layered inorganic nano-powder modified bitumen

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