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Sequential injection spectrophotometric determination of nanomolar nitrite in seawater by on-line preconcentration with HLB cartridge

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Acta Oceanologica Sinica 2010年第1期29卷 100-107页

作者： ZHANG Min YUAN Dongxing HUANG Yongming CHEN Guohe ZHANG Zhen state key laboratory of Marine Environmental Science Enviromnental Science Research Center Xiamen University Xiamen 361005 China College of Life Science Shaoxing University Shaoxing 312000 China

The unstable state of nitrite results in its very low concentration in seawater, which is below the limit of detection （LOD） of conventional techniques of analysis. Some sensitivity-enhanced methods have been proposed for the determination of nitrite at nanomolar level to illustrate the role of nitrite in the marine nitrogen cycle. However, most of previous reports are not widely accepted, because of their complexity and cost equipment or intensive labor requirement. In this study, a simple automatic system for the determination of nanomolar level nitrite using on-line preconcentration with spectrophotometric detection was described..An Oasis HLB cartridge was adopted to quantitatively enrich the pink-colored azo compound, formed from nitrite via Griess reaction. The cartridge was rinsed with water and ethanol （volume fraction is 55%, the same below）, in turn, then eluted by an eluent containing 50% ethanol and 0.25 M（mol/dm^3） H2SO4, and determined at 543 nm with a 2 cm path-length flow cell. Under the optimized experimental conditions, the calibration curve showed a good linearity in the range of 1.4 85.7 aM, and the LOD （3a） was estimated to be 0.5 nM. The relative standard deviations of 7 measurements were 4.0% and 1.0% for the samples spiked at 7.1 and 28.6 nM, respectively. The recoveries for the different natural water samples were between 92.2%-108.4%. Each HLB cartridge could be reused for at least 50 times. As compared with other SPE methods, the advantages of this method included the free of interference from salinity variation and less sample consuming. The results of the application of the proposed method to natural water showed good agreement with liquid waveguide capillary cell detection method.

关键词： nitrite seawater on-line preconcentration sequential injection solid phase extraction

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DCMB that Combines Divide-and-Conquer（DC）and Mixed-Basis Set（MB）Methods for Accurate Geometry Optimizations,Total Energies,and Vibrational Frequencies of Large Molecules

DCMB that Combines Divide-and-Conquer（DC）and Mixed-Basis S...

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中国化学会第28届学术年会

作者： Anan Wu1,Xin Xu1,2 1 state key laboratory of physical chemistry of solid surfaces,Fujian Provincial key laboratory of Theoretical and Computational chemistry,College of chemistry and Chemical Engineering,xiamen university,xiamen 361005,china 2 MOE laboratory for Computational physical Science,Department of chemistry,Fudan university,Shanghai,200433,china

We present a method,named DCMB,for the calculations of large *** is a combination of a parallel divide-and-conquer（DC）1 method and a mixed-basis（MB）2 set *** this approach,atomic forces,total energy and vibrational frequencies are obtained from a series of MB calculations,which are derived from the target system utilizing the DC *** the fragmentation based methods3-5,all DCMB calculations are performed over the whole target system and no artificial caps are introduced so that it is particularly useful for charged and/or delocalized *** comparing the DCMB results with those from the conventional method,we demonstrate that DCMB is capable of providing accurate prediction of molecular geometries,total energies,and vibrational frequencies of molecules of general *** also demonstrate that the high efficiency of the parallel DCMB code holds the promise for a routine geometry optimization of large complex systems.

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Synthesis and Characteration of a ZnO Chrysanthemum-like Nanostructure Assembled with Arrayed Polycrystal Nanowires of 5nm

Synthesis and Characteration of a ZnO Chrysanthemum-like Nan...

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International Symposium on physical chemistry of Surface Nanostructures and Related Nanomaterials

作者： Zhi-Jie Ma. Su-Yuan Xie Rong-Bin Huang Lan-Sun Zhengstate key laboratory for physical chemistry of solid surfaces Department of chemistry xiamen university xiamen361005 china

＜正＞ We have synthesized a unique ZnO chrysanthemum-like nanostructure assembled witharrayed polycrystal nanowires with the diameter about 5nm in large scale from a simple wetsolution method at room temperature.

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A physical model study of effect of fracture aperture on seismic wave

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Science china Earth Sciences 2008年第S2期51卷 233-240页

作者： WEI JianXin & DI BangRang CNPC key physical Exploration laboratory,china university of Petroleum,Beijing 102248,china 1. CNPC key physical Exploration laboratory China University of Petroleum Beijing 102248 China

Based on Hudson’s theoretical hypothesis of equivalent fracture model,inserting aligned round chips in solid model can simulate fractured media. The effect of fractures on the propagation of P and S waves can be observed by changing the fracture thickness. The base model is made of epoxy resin,and the material of fractures is a kind of low-velocity mixture containing silicon rubber. With constant diameter and number of fractures in each model,one group of models can be formed through changing the thickness of fracture. These models have the same fracture density. By using the ultrasonic pulse transmission method,the experiment records time and waveform of P and S waves in the direction parallel and perpendicular to the fracture orientation. The result shows that,with the same fracture density,changing fracture aperture will affect both velocity and amplitude of P and S waves,and the effect on P-wave amplitude is much greater than that on the velocity. Moreover,the variation in velocity of S wave is more obvious in the slow shear wave (S2),while the variation in amplitude is more obvious in the fast shear wave (S1). These properties of wave propagation are useful for seismic data processing and interpretation.

关键词： fracture aperture Hudson’s fracture theory fractured model P-and S-wave velocity amplitude

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SURFACE　SPECIES　OVER　Zro2　SUPPORTED　Ru－Fe　BIMETALLIC　CATALYSTS　IN　CO　HYDROGENATION

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Chinese Journal of Catalysis 1995年第5期 341-342页

作者： Xu, Hui-zhen Guo, Zhong-ru (Department of Chemical Engrineering, Zhejiang university Of Technology, Hangzhou 310014)Wang, Hai-you and Lin, Zhong-yu(Stale key laboratory for physical chemistry of the solid Surface,xiamen university, Xianten 361005)

ＳＵＲＦＡＣＥ　ＳＰＥＣＩＥＳ　ＯＶＥＲ　Ｚｒｏ２ＳＵＰＰＯＲＴＥＤ　Ｒｕ－Ｆｅ　ＢＩＭＥＴＡＬＬＩＣ　ＣＡＴＡＬＹＳＴＳ　ＩＮ　ＣＯ　ＨＹＤＲＯＧＥＮＡＴＩＯＮＳＵＲＦＡＣＥＳＰＥＣＩＥＳＯＶＥＲＺｒｏ２ＳＵＰＰＯ... 详细信息

ＳＵＲＦＡＣＥ　ＳＰＥＣＩＥＳ　ＯＶＥＲ　Ｚｒｏ２ＳＵＰＰＯＲＴＥＤ　Ｒｕ－Ｆｅ　ＢＩＭＥＴＡＬＬＩＣ　ＣＡＴＡＬＹＳＴＳ　ＩＮ　ＣＯ　ＨＹＤＲＯＧＥＮＡＴＩＯＮＳＵＲＦＡＣＥＳＰＥＣＩＥＳＯＶＥＲＺｒｏ２ＳＵＰＰＯＲＴＥＤＲｕ－ＦｅＢＩＭＥＴＡ...

关键词： zirconia ruthenium iron bimetallic catalyst surface species carbon monoxide hydrogenation

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OXIDATIVE DEHYDROGENATION OF ETHANE ON LANTHANUM OXIDE CATALYSTS

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Journal of Energy chemistry 1994年第3期 286-294页

作者： CAI Jun-Xiu HUANG Ai-MinZHOU Xiao-Ping WAN Hui-LinDepartment of chemistry, xiamen university xiamen, Fujtan 361005

The oxidative dehydrogenation of ethane has been studied with vari-ous lanthanum oxide *** kind of catalysts is active and selective inoxidative dehydrogenation of ethane even at temperature of 673’K. The effectsof s... 详细信息

关键词： Zr OXIDATIVE DEHYDROGENATION OF ETHANE ON LANTHANUM OXIDE CATALYSTS

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A Time Dependent Density Functional Theory Study of α-84 and β-84/155 Phycocyanobilin Chromophore in C-Phycocyanin

A Time Dependent Density Functional Theory Study of α-84 an...

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中国化学会第九届全国量子化学学术会议

作者： Jian Wan, Yanliang Ren, Lin Chen, Lihua Zhang, Xin Xu key laboratory of Pesticide & Chemical Biology (CCNU), Ministry of Education College of chemistry, Central china Normal university, Wuhan 430079 state key laboratory for physical chemistry of solid surfaces Department of chemistry, Center for Theoretical chemistry, xiamen university, xiamen 361005

＜正＞The optical characteristics of absorption and circular dichroism （CD） spectroscopy of α- and β-subunit of C-phycocyanin （C-PC） were investigated by using time dependent density functional theory （TDDFT） combined with the polarizable continuum model （PCM）. When the protonation of α- and β-phycocyanobilin （PCB） and their interaction with the protein moiety in C-PC have been taken into account, satisfactory assignment of the absorption and CD spectra of α- and β-PCB can be

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Design and Synthesis of Spin-Crossover Compounds

Design and Synthesis of Spin-Crossover Compounds

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中国化学会第六届全国结构化学学术会议

作者： Jun Tao~*,Feng Shao,Xue-Ru Wu,Rong-Bin Huang,Lan-Sun Zheng state key laboratory of physical chemistry of solid surfaces and Department of chemistry, College of chemistry and Chemical Engineering,xiamen university,xiamen,361005

＜正＞Spin crossover（SCO） compounds can display switchable chemical and physical properties,hence they are of potential applications in molecular scale switches,memory devices and medicinal diagnostics. Recently,an ...

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The Electrochemical Behavior of Ascorbic Acid in the DMPC Biomimetic Membrane

The Electrochemical Behavior of Ascorbic Acid in the DMPC Bi...

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The Eleventh International and the First Sino-Japan Bilateral Symposium on Electroanalytical chemistry

作者： Li TIAN Jin QIU Dong-Mei ZENG Kai YANG Sheng-Pei CHEN Shi-Gang SUN~* state key laboratory of physical chemistry of solid surfaces,School of chemistry and Chemical Engineering,Department of chemistry,xiamen university,xiamen 361005,china

Because of its importance in biochemical and biomedical process,L-ascorbic acid(AA)and its electrochemical oxidation have attracted considerable interests in electrocatalysis and electrochemical sensor *** this study,the electrochemical behavior and FTIR properties of Ascorbic Acid was studied in a mimetic biomembrane which is made of a DMPC cast lipid film deposited onto an Au electrode.

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The Electrochemical Studies on Carbon Nanotube Array Electrodes

The Electrochemical Studies on Carbon Nanotube Array Electro...

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International Symposium on physical chemistry of Surface Nanostructures and Related Nanomaterials

作者： Quan-Yong Gao Jing Zhang Yong Yangstate key Lab for physical chemistry of solid surfaces Department of chemistry xiamenuniversity xiamen361005 china

＜正＞ The studies on nano-structured electrodes have attacted more and more interests in the lastdecades because it shows many potential aplications in electrochemical capacitors,electrochemical sensors and power sources. Arrayed nanowires or nanotubes can be preparedas an array electrodes which can be used as a good model system to study the electrochemicalbehavior of nano-structured materials such as the intercalation behavior of Li-ions in carbon

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