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2007

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Articles 2431 - 2460 of 6758

Full-Text Articles in Physical Sciences and Mathematics

A Survey Of Attacks On Reputation Systems, Kevin Hoffman, David Zage, Cristina Nita-Rotaru May 2007

A Survey Of Attacks On Reputation Systems, Kevin Hoffman, David Zage, Cristina Nita-Rotaru

Department of Computer Science Technical Reports

No abstract provided.

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Temporally Correlated Dirichlet Processes In Pollution Receptor Modeling, Matthew J. Heaton May 2007

Temporally Correlated Dirichlet Processes In Pollution Receptor Modeling, Matthew J. Heaton

Theses and Dissertations

Understanding the effect of human-induced pollution on the environment is an important precursor to promoting public health and environmental stability. One aspect of understanding pollution is understanding pollution sources. Various methods have been used and developed to understand pollution sources and the amount of pollution those sources emit. Multivariate receptor modeling seeks to estimate pollution source profiles and pollution emissions from concentrations of pollutants such as particulate matter (PM) in the air. Previous approaches to multivariate receptor modeling make the following two key assumptions: (1) PM measurements are independent and (2) source profiles are constant through time. Notwithstanding these assumptions, …

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Introduction (2007), Angela Hare May 2007

Introduction (2007), Angela Hare

ACMS Conference Proceedings 2007

Sixteenth Conference of the Association of Christians in the Mathematical Sciences

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Measurement Of D* ± Meson Production In E± P Scattering At Low Q2, S. Chekanov, M. Derrick, S. Magill, S. Miglioranzi, B. Musgrave, D. Nicholass, J. Repond, R. Yoshida, Margarita C. K. Mattingly, M. Jechow, N. Pavel, A. G. Yagües Molina, S. Antonelli, P. Antonioli, G. Bari, M. Basile, L. Bellagamba, M. Bindi, D. Boscherini, A. Bruni, G. Bruni, L. Cifarelli, F. Cindolo, A. Contin, M. Corradi, S. De Pasquale, G. Iacobucci, A. Margotti, R. Nania, A. Polini, L. Rinaldi May 2007

Measurement Of D* ± Meson Production In E± P Scattering At Low Q2, S. Chekanov, M. Derrick, S. Magill, S. Miglioranzi, B. Musgrave, D. Nicholass, J. Repond, R. Yoshida, Margarita C. K. Mattingly, M. Jechow, N. Pavel, A. G. Yagües Molina, S. Antonelli, P. Antonioli, G. Bari, M. Basile, L. Bellagamba, M. Bindi, D. Boscherini, A. Bruni, G. Bruni, L. Cifarelli, F. Cindolo, A. Contin, M. Corradi, S. De Pasquale, G. Iacobucci, A. Margotti, R. Nania, A. Polini, L. Rinaldi

Faculty Publications

The production of D* ± (2010) mesons in e± p scattering in the range of exchanged photon virtuality 0.05 < Q2 < 0.7 GeV2 has been measured with the ZEUS detector at HERA using an integrated luminosity of 82 pb-1. The decay channels D* + → D0 π+ with D0 → K- π+ and corresponding antiparticle decay were used to identify D* mesons and the ZEUS beampipe calorimeter was used to identify the scattered electron. Differential D* cross sections as functions of Q2, inelasticity, y, transverse momentum of the D* meson, pT (D*), and pseudorapidity of the D* meson, η (D*), have been measured in the kinematic region 0.02 < y < 0.85, 1.5 < pT (D*) < 9.0 GeV and | η (D*) | < 1.5. The measured differential cross sections are in agreement with two different NLO QCD calculations. The cross sections are also compared to previous ZEUS measurements in the photoproduction and DIS regimes. © 2007 Elsevier B.V. All rights reserved.

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Education In The Environment: A Hands-On Student Research And Outdoor Learning Experience: Final Project Report, Environmental Education Strategy For Nevada May 2007

Education In The Environment: A Hands-On Student Research And Outdoor Learning Experience: Final Project Report, Environmental Education Strategy For Nevada

Reports (PLI Education)

Education in the Environment: A Hands‐on Student Research and Outdoor Learning Experience is a Round 4 Southern Nevada Public Land Management Act (SNPLMA)‐funded project implemented by the University of Nevada, Las Vegas Public Lands Institute on behalf of and in cooperation with four Federal agencies in Southern Nevada. This project consisted of three components: (1) an Interagency Conservation Education and Interpretation Strategy; (2) Discover Mojave Forever Earth, an environmental laboratory and learning center; and (3) Southern Nevada Discover Mojave Outdoor World program.

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Collaborative Research: Late Quaternary History Of Reedy Glacier, Brenda Hall May 2007

Collaborative Research: Late Quaternary History Of Reedy Glacier, Brenda Hall

University of Maine Office of Research Administration: Grant Reports

The stability of the marine West Antarctic Ice Sheet (WAIS) remains an important, unresolved problem for predicting future sea level change. Recent studies indicate that the mass balance of the ice sheet today may be negative or positive. The apparent differences may stem in part from short-term fluctuations in flow. By comparison, geologic observations provide evidence of behavior over much longer time scales. Recent work involving glacial-geologic mapping, dating and ice-penetrating radar surveys suggests that deglaciation of both the Ross Sea Embayment and coastal Marie Byrd Land continued into the late Holocene, and leaves open the possibility of ongoing deglaciation …

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Schedule (2007), Association Of Christians In The Mathematical Sciences May 2007

Schedule (2007), Association Of Christians In The Mathematical Sciences

ACMS Conference Proceedings 2007

Sixteenth Conference of the Association of Christians in the Mathematical Sciences

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Table Of Contents (2007), Association Of Christians In The Mathematical Sciences May 2007

Table Of Contents (2007), Association Of Christians In The Mathematical Sciences

ACMS Conference Proceedings 2007

Sixteenth Conference of the Association of Christians in the Mathematical Sciences

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Corrigendum, Re: The Structure Of The Cos2 (100)-(1×1) Surface, Z. X. Yu, M. A. Van Hove, S. Y. Tong, David Wisbey, Yaroslav B. Losovyj, Ning Wu, M. Manno, L. Wang, C. Leighton, Wai-Ning Mei, Peter A. Dowben May 2007

Corrigendum, Re: The Structure Of The Cos2 (100)-(1×1) Surface, Z. X. Yu, M. A. Van Hove, S. Y. Tong, David Wisbey, Yaroslav B. Losovyj, Ning Wu, M. Manno, L. Wang, C. Leighton, Wai-Ning Mei, Peter A. Dowben

Peter Dowben Publications

Different surface terminations have been previously discussed in reference [12] of J. Phys.: Condens. Matter 19 156223 (i.e., Ying Jiu Jin and Jae Il Lee 2006 Phys. Rev. B 73 064405) and we inadvertently failed to properly cite this reference in the attribution of figure 3 of our paper.

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Albumin-Binding Paracest Agents, M. Meser Ali, Mark Woods, Eul Hyun Suh, Zoltan Kovacs, Gyula Tircsó, Piyu Zhao, Vikram D. Kodibagkar, A. Dean Sherry May 2007

Albumin-Binding Paracest Agents, M. Meser Ali, Mark Woods, Eul Hyun Suh, Zoltan Kovacs, Gyula Tircsó, Piyu Zhao, Vikram D. Kodibagkar, A. Dean Sherry

Chemistry Faculty Publications and Presentations

Lanthanide complexes (Eu3+, Gd3+ and Yb3+) of two different 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid tetraamide derivatives containing two (2) and four (3) O-benzyl-L-serine amide substituents were synthesized and their chemical exchange saturation transfer (CEST) and relaxometric properties were examined in the presence and absence of human serum albumin (HSA). Both Eu2 and Eu3 display a significant CEST effect from a single slowly exchanging Eu3+-bound water molecule, making these PARACEST complexes potentially useful as vascular MRI agents. Yb2 also showed a detectable CEST effect from both the Yb3+-bound water protons and the …

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Director Dynamics In Liquid-Crystal Physical Gels, Rafael Verduzco, Neal R. Scruggs, Samuel Sprunt, Peter Palffy-Muhoray, Julia A. Kornfield May 2007

Director Dynamics In Liquid-Crystal Physical Gels, Rafael Verduzco, Neal R. Scruggs, Samuel Sprunt, Peter Palffy-Muhoray, Julia A. Kornfield

Peter Palffy-Muhoray

Nematic liquid- crystal (LC) elastomers and gels have a rubbery polymer network coupled to the nematic director. While LC elastomers show a single, non- hydrodynamic relaxation mode, dynamic light- scattering studies of self- assembled liquid- crystal gels reveal orientational fluctuations that relax over a broad time scale. At short times, the relaxation dynamics exhibit hydrodynamic behavior. In contrast, the relaxation dynamics at long times are non-hydrodynamic, highly anisotropic, and increase in amplitude at small scattering angles. We argue that the slower dynamics arise from coupling between the director and the physically associated network, which prevents director orientational fluctuations from decaying …

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Collaborative Research: Chronology Of Ice Fluctuations In The South Shetland Islands Since The Last Glacial Maximum, Brenda L. Hall May 2007

Collaborative Research: Chronology Of Ice Fluctuations In The South Shetland Islands Since The Last Glacial Maximum, Brenda L. Hall

University of Maine Office of Research Administration: Grant Reports

This award supports a study of the timing of climate changes in the Southern Hemisphere with the goal of reconstructing former ice extent and fluctuations, as well as paleoclimate, along the key latitudinal transect from temperate Tierra del Fuego to the polar Antarctic Peninsula. Samples already in hand will allow the dating of ice fluctuations in the South Shetland Islands (SSI), a critical location where that transect crosses the Antarctic Convergence. Surprisingly little concrete evidence exists concerning former ice extent in the island chain. The results of this study will answer a number of basic questions regarding ice extent and …

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On The Parameterization Dependence Of The Energy Momentum Tensor And The Metric, N. E. J. Bjerrum-Bohr, John Donoghue, Barry R. Holstein May 2007

On The Parameterization Dependence Of The Energy Momentum Tensor And The Metric, N. E. J. Bjerrum-Bohr, John Donoghue, Barry R. Holstein

John Donoghue

We use results by Kirilin to show that in general relativity the nonleading terms in the energy-momentum tensor of a particle depends on the parameterization of the gravitational field. While the classical metric that is calculated from this source, used to define the leading long-distance corrections to the metric, also has a parameteriztion dependence, it can be removed by a coordinate change. Thus the classical observables are parameterization independent. The quantum effects that emerge within the same calculation of the metric also depend on the parameterization and a full quantum calculation requires the inclusion of further diagrams. However, within a …

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Laboratory Findings In Acute Cytauxzoon Felis Infection In Cougars (Puma Concolor Couguar) In Florida, John W. Harvey, Mike R. Dunbar, Terry M. Norton, Michael J. Yabsley May 2007

Laboratory Findings In Acute Cytauxzoon Felis Infection In Cougars (Puma Concolor Couguar) In Florida, John W. Harvey, Mike R. Dunbar, Terry M. Norton, Michael J. Yabsley

United States Department of Agriculture Wildlife Services: Staff Publications

Intraerythrocytic piroplasms, morphologically indistinguishable from Cytauxzoon felis, were identified in stained blood films from more than one third of free-ranging cougars (Puma concolor cougar) in southern Florida in a study that failed to demonstrate negative effects of piroplasm infection on measured hematologic parameters. However, a recent study with a nested 18s rRNA polymerase chain reaction (PCR) assay identified only 9% of the free-ranging cougars in southern Florida as infected with C. felis but found 83% of these animals were infected with an unnamed small Babesia sp. In this study, hematology and clinical chemistry parameters were determined during …

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Scml: A Structural Representation For Chinese Characters, Daniel G. Peebles May 2007

Scml: A Structural Representation For Chinese Characters, Daniel G. Peebles

Dartmouth College Undergraduate Theses

Chinese characters are used daily by well over a billion people. They constitute the main writing system of China and Taiwan, form a major part of written Japanese, and are also used in South Korea. Anything more than a cursory glance at these characters will reveal a high degree of structure to them, but computing systems do not currently have a means to operate on this structure. Existing character databases and dictionaries treat them as numerical code points, and associate with them additional `hand-computed' data, such as stroke count, stroke order, and other information to aid in specific searches. Searching …

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Parametrization Dependence Of The Energy-Momentum Tensor And The Metric, Nej Bjerrum-Bohr, Jf Donoghue, Br Holstein May 2007

Parametrization Dependence Of The Energy-Momentum Tensor And The Metric, Nej Bjerrum-Bohr, Jf Donoghue, Br Holstein

Barry R Holstein

We use results by Kirilin to comment that in general relativity the nonleading terms in the energy-momentum tensor of a particle depends on the parameterization of the gravitational field. The classical observables are parameterization independent after a change in coordinates. The quantum effects that emerge within the same calculation of the metric also depend on the parameterization and a full quantum calculation requires the inclusion of further diagrams. However, within a given parameterization the quantum effects calculated by us in a previous paper are well defined. Flaws of Kirilin’s proposed alternate metric definition are described and we explain why the …

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Electricity Generation From A Microbial Fuel Cell Employing Desulfovibrio Salexigens, Ping Ding, Hai-Bo Shao, Guang-Zhou Liu, Dong-Xia Duan, Ting Ma, Si-Jun Chen, Jian-Ming Wang, Jian-Qing Zhang May 2007

Electricity Generation From A Microbial Fuel Cell Employing Desulfovibrio Salexigens, Ping Ding, Hai-Bo Shao, Guang-Zhou Liu, Dong-Xia Duan, Ting Ma, Si-Jun Chen, Jian-Ming Wang, Jian-Qing Zhang

Journal of Electrochemistry

A microbial fuel cell of laboratory scale employing Desulfovibrio salexigens in lactate based seawater substrate was proposed.Electricity was continuously harvested after inoculation.During 20 days of fermentation/discharge,COD values of the substrate decreased by 61.7%,in which 9.81% was converted to electricity.

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Hydriding And Dehydriding Properties Of Mg/Mg_(1.8)La_(0.2)Ni Nanocomposites, Hong-Liang Sun, Yan-Yan Zhang, Hai-Chang Zhang, Hua-Bin Yang, Zuo-Xiang Zhou May 2007

Hydriding And Dehydriding Properties Of Mg/Mg_(1.8)La_(0.2)Ni Nanocomposites, Hong-Liang Sun, Yan-Yan Zhang, Hai-Chang Zhang, Hua-Bin Yang, Zuo-Xiang Zhou

Journal of Electrochemistry

Mg-x %Mg1.8La0.2Ni(x=10,20 and 30)nanocomposites have been synthesized by high-energy ball milling method.Results of the X-ray diffraction(XRD),transmission electron microscopy(TEM)and selected area electron diffraction(SAED)tests were showed that each composite had a nanocrystalline/amorphous structure,which was beneficial for the improvement of the hydriding and dehydriding properties of Mg.The hydrogen absorption temperature decreased and the hydrogen sorption kinetics were improved.Under the conditions of 423 K and the hydrogen pressure of 2.5MPa,each composite could reach the maximum hydriding capacity within 50 s.

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Electrochemical Performance Of Li_(1-X)M_Xfepo_4 Cathode Materials Synthesized By Polymer Pyrolysis Route, Ting Li, Jiang-Feng Qian, Yu-Liang Cao, Han-Xi Yang, Xin-Ping Ai May 2007

Electrochemical Performance Of Li_(1-X)M_Xfepo_4 Cathode Materials Synthesized By Polymer Pyrolysis Route, Ting Li, Jiang-Feng Qian, Yu-Liang Cao, Han-Xi Yang, Xin-Ping Ai

Journal of Electrochemistry

Olivine Li1-xMxFePO4(M=Cr3+、Mg2+、Mn2+、Ni2+)were synthesized by a polyacrylates-pyrolysis route.The structural and electrochemical properties of the as-synthesized cathode materials were investigated by powder X-ray diffraction(XRD),scanning electron microscopy(SEM),and electrochemical charge/discharge cycling.The results indicate that the metallic ions doped at low concentration do not affect the crystalline structure of the material,but considerably improve the rate capability and cycle performance of LiFePO4 at high rate.

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Template Synthesis And Electrochemical Studies Of Ag_(Core)Au_(Shell) Nanowires, Li Ling, Ya-Xian Yuan, Min-Min Xu, Jian-Lin Yao, Ren-Ao Gu May 2007

Template Synthesis And Electrochemical Studies Of Ag_(Core)Au_(Shell) Nanowires, Li Ling, Ya-Xian Yuan, Min-Min Xu, Jian-Lin Yao, Ren-Ao Gu

Journal of Electrochemistry

Agcore Aushell nanowires with different thicknesses were prepared by combining template synthesis and chemical reduction method,and characterized by SEM and cyclic voltammetry(CV).The CV results revealed that the AgcoreAushell nanowires with pinhole were transferred to pinhole free structure after several potential scans.By using thiophenol(TP)and p-aminothiophenol(PATP)as probe,the surface enhanced Raman scattering(SERS)effect was investigated on the core-shell nanowires.The results indicated that AgcoreAushell nanowires could be served as a potential SERS substrate,and the difference in the spectral feature of PATP adsorbed onto Au and Ag nanowires enable us to diagnose the pinhole effect of core-shell nanowires by SERS.

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Simulation Of A Packed-Bed Electrochemical Reactor With Cooled Cathode For Continuously Producing Glyoxylic Acid By Oxalic Acid, Qing-Biao Li, Xiao-Hui Hu, Xue-Yun Chen, Wei Li, Yu-Zhong Su, Jun Li May 2007

Simulation Of A Packed-Bed Electrochemical Reactor With Cooled Cathode For Continuously Producing Glyoxylic Acid By Oxalic Acid, Qing-Biao Li, Xiao-Hui Hu, Xue-Yun Chen, Wei Li, Yu-Zhong Su, Jun Li

Journal of Electrochemistry

Oxalic acid electrochemical reduction has been suggested as an important technology to produce glyoxylic acid;the packed-bed electrochemical reactor with cooled cathode(PERCC)has been proposed to solve the problem of lower space-time-yield that appeared in the parallel electrode reactor.Based on the mass balance equations,charge balance equations and kinetics equations of the system,a two-dimensional reactor model was established to describe the continuous operation process for producing glyoxylic acid from oxalic acid by PERCC.Using the orthogonal collocation method,the model equations could be numerically solved,and the glyoxylic concentration along the reactor length could be simulated.The modeling results indicated that the glyoxylic concentration increased quickly at …

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The Research Of Several Electrodes For Spe Water Electrolysis, Jian-Bo Meng, Ge Sang, Yan Xue, Wei Cao, Xiao-Qiu Ye May 2007

The Research Of Several Electrodes For Spe Water Electrolysis, Jian-Bo Meng, Ge Sang, Yan Xue, Wei Cao, Xiao-Qiu Ye

Journal of Electrochemistry

Performances of the IrRu/Nafion 117/PbAg,IrRu/Nafion 117/Ni,IrRu/Nafion 117/TiNi,Ag/Nafion 117/Ni and C/Nafion 117/PtRu for the SPE water electrolysis have been investigated.The order of the electrocatalysis activity for the anodic electrodes as mentioned above is IrRu>Ag>C,and that of cathodic electrode is Ni>PbAg>TiNi.While the stability of TiNi was much better than Ni,and that of PbAg is best.Moreover,the current efficiency was raised with the increase of current density.

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Electrochemical Reduction Of Coals And The Oxygenic Functional Simulacrums Of Coals, Juan Lin, Zhao Wei May 2007

Electrochemical Reduction Of Coals And The Oxygenic Functional Simulacrums Of Coals, Juan Lin, Zhao Wei

Journal of Electrochemistry

Electrochemical reduction of coals and the oxygenic functional simulacrums of coals has been studied.In this process,tetrabutylammonium was used as supporting electrolyte.The coal and the deoxidized coal were extracted by methanol.Qualitative analysis of the deoxidized products and the extractives was carried out on gas chromatograph-mass spectrometer.The deoxidized products of the oxygenic functional simulacrums of coals were analysed quantitatively with gas chromatograph spectrometer.The results show that the oxygenic functional groups on the coals surface decrease and the translation ratios of the oxygenic functional simulacrums of coals need further increase after electrochemical reduction,.The electrochemical tests show simultaneously the kinetics equations of every related …

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Study On The Electricity Capability Of Ru_((0.4-X))Ir_Xti_(0.6)/Ti Electrode, Ling-Li Wang, Qiao Peng May 2007

Study On The Electricity Capability Of Ru_((0.4-X))Ir_Xti_(0.6)/Ti Electrode, Ling-Li Wang, Qiao Peng

Journal of Electrochemistry

The metal oxide anode of Ru(0.4-x)IrxTi0.6 has been prepared by thermal decomposition.The results indicate that,when the percent of IrO2 is 10%,the electrode has low chlorine potential,high oxygen potential and excellent catalyze selectivity;strengthen life is long with IrO2 content increased from 1.0h to 97h.It shows that the electrode anti-oxide corrosion perform is improved and intensifying life is long with addition of IrO2.The film and reaction resistance are all fall with the addition of IrO2.The addition of IrO2 is in favor of thin crystal and makes the film more roughness.

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Study On The Characteristics Of Vb_(12) Modified Electrode By Electropolymerization, Hui-Ting Lian, Wen-Ji Wang May 2007

Study On The Characteristics Of Vb_(12) Modified Electrode By Electropolymerization, Hui-Ting Lian, Wen-Ji Wang

Journal of Electrochemistry

Preparation of the VB12 modified electrode and its electrochemical characteristics were studied.The results showed that the VB12 after electroactivated is able to electopolymerize on the GC by cyclic voltammetry(CV)in the DMSO solution.Differential pulse voltmmetry(DPV)showed that the VB12 catalyzed the oxidation of NO2-,SO32-and NH2NH2.The catalytic peak for NO2-on the modified electrode was observed at 0.76V(vs.SCE),but on the unmodified GC which at 1.0V.The catalytic currents increased linearly with the concentration of NO2-from 1.6×10-6 to 4.3×10-4 mol·L-1 with a correlation coefficient of 0.9987.The VB12 modified electrode showed excellent stability and high sensitivity to determined the NO2-in the rains and lake waters with a …

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Self Assemblying Kinetics Of Sodium Steareate At Castor Oil/Water Interface, Yong-Chun Zhu, Li-Na Tang, Hong-Guo Ji May 2007

Self Assemblying Kinetics Of Sodium Steareate At Castor Oil/Water Interface, Yong-Chun Zhu, Li-Na Tang, Hong-Guo Ji

Journal of Electrochemistry

The self assembly membrane(SAM)formation kinetics of sodium stearate at castor oil/water interface was studied by cyclic voltammetrry.At caster oil coated graphite-epoxy solid electrode surface,the SAM grows according to the Gaussian growth function with a rate constant of km=0.0006292(0.0000294)s-1,and maximum particle size at t0=3127s.The SAM of sodium stearate controls the growth and particle size of the deposited copper nano particles well,and forms a composite membrane of the SAM and copper nano particle.The growth mechanism of copper particle at oiled electrode or SAM modified oiled electrode is spherical growth,while it is the semi-spherical growth at bared graphite-epoxy solid phase electrode.Compared with castor …

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Study On Fenbufen Electrochemical Behavior By The Linear Scanning Polarographic Method, Tian-Yang Xie, Hong-Gui Tuo, Ma-Tai Ding May 2007

Study On Fenbufen Electrochemical Behavior By The Linear Scanning Polarographic Method, Tian-Yang Xie, Hong-Gui Tuo, Ma-Tai Ding

Journal of Electrochemistry

The electrochemical behavior of fenbufen had been studied by linear scanning polarographic method.In 0.2mol L-1 phosphate buffer solution(pH6.86),a sensitive reductive wave of fenbufen appeared at-1.38 V(vs.SCE).The linear relationship between the peak current and the fenbufen concentration in the range of 1.6～200.0 mg·L-1(r=0.9958,n=10)were observed,the detection limit of this method was 0.8 mg·L-1.RSD is 0.73%,found from the data of 6 independent determinations at the concentration level of 80.0 mg·L-1.recovery ratio is 97.7%～109.2%.This fenbufen's electrochemical characteristic property may be used to determining the contents of tablets.

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Determination Of Tetracyclines Based On The Flow-Through Electrochemical Detection Cell With Nickel Electrode, Dan-Mei Pan, Rong-Zong Hu, Dong-Ping Wei, Hao-Dong Ding May 2007

Determination Of Tetracyclines Based On The Flow-Through Electrochemical Detection Cell With Nickel Electrode, Dan-Mei Pan, Rong-Zong Hu, Dong-Ping Wei, Hao-Dong Ding

Journal of Electrochemistry

The electrochemical responses to tetracycline at the nickel electrode in alkaline solution were compared with that of gold and glassy carbon electrode by voltammetry.The electrocatalytic oxidation characteristics of tetracycline at nickel electrode were discussed.Subsequently a flow-through amperometric detection cell with nickel as the working electrode was designed to detect tetracycline,oxytetracycline,and doxycycline.Standard calibration graphs for the tetracyclines yielded linear ranges of 0.1~15 mg/L.Detection limits(S/N=3)of 35,45 and 43 μg/L were obtained for tetracycline,oxytetracycline and doxycycline,respectively.The system was applied for the determination of the three antibiotics in single-component drug formulations.

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Determination Of Ddopamine And Ascorbate On Gold Nanoparticle And 4,4-Bis (Methanethiol) Biphenyl (Mtp) Self-Assembled Monolayer Modified Gold Electrode, Hai-Yan Wang, Peng Liu, Ye Wang, Bao-Kang Jin May 2007

Determination Of Ddopamine And Ascorbate On Gold Nanoparticle And 4,4-Bis (Methanethiol) Biphenyl (Mtp) Self-Assembled Monolayer Modified Gold Electrode, Hai-Yan Wang, Peng Liu, Ye Wang, Bao-Kang Jin

Journal of Electrochemistry

A new approach to construct an ampermetric biosensor was described.The 4,4-bis(methanethiol)biphenyl(MTP)is adsorbed on to a bare gold electrode to make self-assembled monolayers(MTP/Au SAMs).Then electrodeposited 2mg/mL HAuCl4 at-200 mV,NG/MTP/Au electrode was prepared.When a differential pulse voltammetric(DPV)technique was used,the peak separation between DA and AA is 155 mV.Hence,the selective determination of dopamine(DA)and ascorbate(AA)in the binary mixture system can be performed.Under the chosen conditions,the peak currents are correspondent linearly to the concentrations of DA and AA in the range of 5.0×10-7~1×10-4 mol·L-1 and 3.5×10-6~1.0×10-3mol·L-1,respectively.The correlation coefficients were 0.998.The detection limit were 1.5×10-7 mol·L-1 and 1.2×10-6 mol·L-1for DA and AA.

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Catalysis Of Nano Tio_2 For Horseradish Peroxidase, Ya-Qi Zhu, Hai Wu, Hiu Liu, Jie Ma May 2007

Catalysis Of Nano Tio_2 For Horseradish Peroxidase, Ya-Qi Zhu, Hai Wu, Hiu Liu, Jie Ma

Journal of Electrochemistry

Horseradish peroxidase immobilized on the surface of titanium dioxide nanoparticles and nanotube modified glassy carbon electrode.The HRP direct electron transfer reaction was compared between TiO2 nanoparticles and nanotube GC electrode.The results demonstrated that the HRP on TiO2 nanotube /GC electrode could catalyze electron exchange reaction between electroactivity center of HRP and electrode.And the research of antibody labeled HRP provides a selected signal for antibody-antigen immunoassay.

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