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2007

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Articles 301 - 330 of 658

Full-Text Articles in Chemistry

The Molecular Basis Of High-Altitude Adaptation In Deer Mice, Jay F. Storz, Stephen J. Sabatino, Federico G. Hoffmann, Eben J. Gering, Hideaki Moriyama, Nuno Ferrand, Bruno Monteiro, Michael W. Nachman Mar 2007

The Molecular Basis Of High-Altitude Adaptation In Deer Mice, Jay F. Storz, Stephen J. Sabatino, Federico G. Hoffmann, Eben J. Gering, Hideaki Moriyama, Nuno Ferrand, Bruno Monteiro, Michael W. Nachman

Hideaki Moriyama Publications

Elucidating genetic mechanisms of adaptation is a goal of central importance in evolutionary biology, yet few empirical studies have succeeded in documenting causal links between molecular variation and organismal fitness in natural populations. Here we report a population genetic analysis of a two-locus a-globin polymorphism that underlies physiological adaptation to high-altitude hypoxia in natural populations of deer mice, Peromyscus maniculatus. This system provides a rare opportunity to examine the molecular underpinnings of fitness-related variation in protein function that can be related to a well-defined selection pressure. We surveyed DNA sequence variation in the duplicated α -globin genes of P. maniculatus …

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Surface Properties Of Licoo2, Linio2 And Lini1-XCoXO2, Anthony W. Moses, Harry G. Garcia Flores, Jong-Gyu Kim, Marjorie Langell Mar 2007

Surface Properties Of Licoo2, Linio2 And Lini1-XCoXO2, Anthony W. Moses, Harry G. Garcia Flores, Jong-Gyu Kim, Marjorie Langell

Marjorie A. Langell Publications

The surface composition and chemical environment of LiCoO2, hexagonal LiNiO2, cubic LiNiO2, and the mixed transition metal oxide LiNi0.5Co0.5O2 have been determined by Auger electron and X-ray photoelectron spectroscopies. While the LiCoO2 surface properties can easily be extrapolated from bulk composition, the nickel-containing materials are less straightforward. Their surface concentration tends to be depleted in lithium relative to that of the bulk and shows an atypical chemical environment for the constituent elements. The Ni 2p XPS photoemission suggests a near “ NiO-like” selvedge through the XPS binding energies …

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The Crystal And Molecular Structure Of A Trifluoroacetylacetonate Complex Of Scandium, Sc(Ch3Cochcocf3)3, Dennis W. Bennett, Tasneem Siddiquee, Daniel T. Haworth, Sergey V. Lindeman Mar 2007

The Crystal And Molecular Structure Of A Trifluoroacetylacetonate Complex Of Scandium, Sc(Ch3Cochcocf3)3, Dennis W. Bennett, Tasneem Siddiquee, Daniel T. Haworth, Sergey V. Lindeman

Chemistry Faculty Research and Publications

The crystal and molecular structure of Sc(CH3COCHCOCF3)3 has been determined by X-ray diffraction. The compound crystallizes as pure mer-isomer in the orthorhombic space group Pbca with lattice parameters a=15.166(8) Å, b=13.560(7) Å, c=19.327(10) Å, α=β=γ=90°, V=3974(4) Å3, Z=8. The complex at 100 K is partially disordered in the crystal structure in an approximate 5:1 ratio with 83% fluorine population at C-11 and 17% at C-15. NMR data is compared to that previously reported.

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Effects Of Direct Current Bias Potentials On Lipid Membranes Forming On A Glassy Carbon Electrode, Yu-Hui Li, Hong-Wei Zhang, Gui-Lan Song, Zhan-Jun Zhang, Sheng-Min Cai Feb 2007

Effects Of Direct Current Bias Potentials On Lipid Membranes Forming On A Glassy Carbon Electrode, Yu-Hui Li, Hong-Wei Zhang, Gui-Lan Song, Zhan-Jun Zhang, Sheng-Min Cai

Journal of Electrochemistry

The effects of direct current(DC) bias voltage on the structure of lipid membranes forming on a glassy carbon electrode(GCE) was investigated by cyclic voltammetry(CV) and electrochemical impedance spectroscopy(EIS).The experiment showed that the lipid membranes can be formed with either positive or negative bias potential exerted.When bias voltage was exerted,bilayer lipid membranes tended to form due to the electrostatic interaction between the superficial positive charges on the polarized electrode and the negative charged part of PC.When the positive bias voltage overrun the range,the lacunas on s-BLMs would increase,and the BLMs would be broken.A proper equivalent circuit was nonlinearly fitted,based on the …

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Charge-Discharge Behaviors And Properties Of A Lab-Scale All-Vanadium Redox-Flow Single Cell, Ping Zhao, Hua-Min Zhang, Yue-Hua Wen, Bao-Lian Yi Feb 2007

Charge-Discharge Behaviors And Properties Of A Lab-Scale All-Vanadium Redox-Flow Single Cell, Ping Zhao, Hua-Min Zhang, Yue-Hua Wen, Bao-Lian Yi

Journal of Electrochemistry

An experimental setup with two external saturated calomel reference electrodes(SCE)and two flow cells was established for flow battery research application.By using this setup,the cell voltage,potentials and open circuit potentials of the positive and negative electrodes for a lab-scale flow battery single cell,could be determined simultaneously during charge-discharge(C-D) cycle test.Then,the ohmic internal resistance drop(iR drop),overpotentials at the negative and positive electrodes of the cell during C-D process,were calculated.The average iR drop accounts for about 74% of the total voltage losses during the C-D cycle at current density of 60 mA·cm-2,suggesting the voltage efficiency(VE) of vanadium redox-flow battery(VRB) single cell …

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Studies On The Ion Conductive Performance Of Composite Polymer Electrolyte Containing Nano-Scale Sio2, Lin Ye, Yu-Mei Zhao, Xiao-Wen Zhang, Zeng-Guo Feng, Ying Bai, Feng Wu Feb 2007

Studies On The Ion Conductive Performance Of Composite Polymer Electrolyte Containing Nano-Scale Sio2, Lin Ye, Yu-Mei Zhao, Xiao-Wen Zhang, Zeng-Guo Feng, Ying Bai, Feng Wu

Journal of Electrochemistry

Nano-silicon oxide was doped into a novel comblike polyether,poly(3-(methoxy(triethylenoxy))methyl-3'-methyloxetane) to prepare a series of composite polymer electrolyte.The ion conductivity measurement revealed that the composite polymer electrolyte added with 5% weight fraction of SiO2 has the highest ion conductivity of 7.8×10-5 S/cm at 30℃ and 4.5×10-4 S/cm at 80℃,which is increased 30%~60% as compared to the polymer electrolyte without adding any SiO2.DSC results implied that the nano-silicon oxide inserts into the macromolecule chains to increase the free volume and decrease the glass transition temperature to enhance the ion conductivity.In addition,it seems that the crystallization occurred due …

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Composite Electroplating And Characterizations Of Sn-Sba15 Anode For Lithium-Ion Batteries, Xiao-Yong Fan, Jin-Mei Xu, Quan-Chao Zhuang, Hong-Hong Jiang, Ling Huang, Yan-Xia Jiang, Quan-Feng Dong, Shi-Gang Sun Feb 2007

Composite Electroplating And Characterizations Of Sn-Sba15 Anode For Lithium-Ion Batteries, Xiao-Yong Fan, Jin-Mei Xu, Quan-Chao Zhuang, Hong-Hong Jiang, Ling Huang, Yan-Xia Jiang, Quan-Feng Dong, Shi-Gang Sun

Journal of Electrochemistry

Sn-SBA15 anode was prepared by composite electroplating. The first discharge and charge capacity was 1075mAh/g and 630mAh/g respectively. After fifty charge/discharge cycles, the charge and discharge capacity of Sn-SBA15 were retained above 400mAh/g. XRD patterns indicated that the Sn-SBA15 has tetragonal crystal type. SEM images showed that the Sn-SBA15 had a honeycombed surface. EIS results indicated that there was SEI film formed on the surface of Sn-SBA15 electrode.

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Electrochemical Oxidation Of The Phenol In The Chloride System, Yong Liu, Dan Liu, Shi-Lin Zhao, Jing-Jing Lai Feb 2007

Electrochemical Oxidation Of The Phenol In The Chloride System, Yong Liu, Dan Liu, Shi-Lin Zhao, Jing-Jing Lai

Journal of Electrochemistry

The Ru-Ir /Ti electrode as cathode to electrolysis the synthetic phenolic wastewater was studied. The effect of the initial chloride concentration on the electrolytic treatment result has been discussed. Experiment result shows that the electrochemical oxidation of phenol suits to one kinetics equation in given electrolytic time. If the initial chloride concentration in wastewater increases, the time of the electrochemical oxidation of phenol can be shorten, in other words the apparent rate constant is greater. The middle matters of electrochemical oxidation of phenol in the chloride system detected out by HPLC and GC-MS is mainly 1-chloro-phenol, 4-chloro-phenol, 2,4-dichloro-phenol, 2,6-dichloro-phenol, 2,4,6-trichloro-phenol, …

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Ac Impedance Study On The Bcx Cells, Hong-Hua Ge, Jun Wang, Jing Liu, Guo-Ding Zhou, Yi-Ping Wu, Gang Wu Feb 2007

Ac Impedance Study On The Bcx Cells, Hong-Hua Ge, Jun Wang, Jing Liu, Guo-Ding Zhou, Yi-Ping Wu, Gang Wu

Journal of Electrochemistry

The electrodes in both Li/SOCl2 cells and BCX cells were studied by ac impedance spectroscopy.The results indicate that the resistance of the electrode passive layer increased with the storage time,then became stabilized in both kinds of cells.But the electrode resistance decreased a lot after adding BrCl into the cells.The resistance of the Li electrode decreased about a half to that without BrCl,and the value of the glassy carbon electrode decreased from about 100 kΩ to 2 kΩ.The huge resistance of the glassy carbon electrode indicates that it is the control electrode of the cell.

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Electrochemical Performance Of 1-Ethyl-3-Methylimidazolium Trifluoroacetic To The Electrolyte Of Electrochemical Double Layer Capacitor, Guo-Hua Sun, Kai-Xi Li, Qiang Li, Hui Fan, Jian-Yu Gu Feb 2007

Electrochemical Performance Of 1-Ethyl-3-Methylimidazolium Trifluoroacetic To The Electrolyte Of Electrochemical Double Layer Capacitor, Guo-Hua Sun, Kai-Xi Li, Qiang Li, Hui Fan, Jian-Yu Gu

Journal of Electrochemistry

The electrochemical performance of an Electrochemical Double Layer Capacitor consisted of higher specific surface area activated carbon and ionic liquid \CF3COO was investigated by constant current charge/discharge and cyclic voltammegrams(CV) methods.The results indicated that the \CF3COO had High specific capacitance,excellent cyclic characteristics and high charge/discharge efficiency.Specific capacitance of the EDLC increased with electrochemical window increase at the range of steady electrochemical window.Energy density increased with current and voltage increase,power density deduced with current increase but increased with electrochemical window increase.These conclusions revealed that the \CF3COO was very suitable for the electrolyte of EDLC.

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Diamond-Like-Carbon Film Prepared On Stainless Steel Substrates By Liquid Phase Electrochemical Deposition, Jing-Yong Du, Gui-Feng Zhang, Guo-Qing Li, Xiao-Duo Hou Feb 2007

Diamond-Like-Carbon Film Prepared On Stainless Steel Substrates By Liquid Phase Electrochemical Deposition, Jing-Yong Du, Gui-Feng Zhang, Guo-Qing Li, Xiao-Duo Hou

Journal of Electrochemistry

Diamond-like carbon (DLC) films were deposited on stainless steel substrates at atmospheric pressure and low temperature (60 ℃) by electrolysis in a methanol solution with a pulseddirect current power supply. The morphology and microstructure of the resulting DLC films were analyzed using atomic force microscopy(AFM), scanning electron microscopy (SEM), Raman spectroscopy and Fourier transformation infrared spectrometry (FTIR). The experimental results show that the hydrogenated diamond-like carbon filmsare smooth and compact. Raman spectroscopy analysis confirmed the presence of a strongpeak at 1332.51 cm-1, which is assigned to crystalline diamond. The deposition rate can be enhanced to 0.5 μm/h by …

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Comparison Of The Electrochemical Reactivity Of Electrodes Modified By Carbon Nanotubes With Different Sizes, Guo-Feng Yang, Neng-Qin Jia, Zhi-Yong Wang Feb 2007

Comparison Of The Electrochemical Reactivity Of Electrodes Modified By Carbon Nanotubes With Different Sizes, Guo-Feng Yang, Neng-Qin Jia, Zhi-Yong Wang

Journal of Electrochemistry

The electrochemical activity of multi-walled carbon nanotubes(MWNTs) with different sizes,including four different MWNTs with the same length and different diameter,two different MWNTs with the same diameter and different length has been assessed and compared.The various MWNTs modified electrodes were prepared by immobilizing the suitable amount of MWNTs onto a glassy carbon electrode,and their voltammetric responses to ferricyanide,uric acid and dopamine were examined.The corresponding cyclic voltammetric data was showed that the electrochemical and electrocatalytic activities are depended on the nanotube length.The electrochemical reactivity of short MWNT(S-MWNT) is better than that of long MWNT(L-MWNT),which may be mainly attributed to the existence of …

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Mwnts Modified Gc Electrode For Hydrogen Peroxide Determination, Hong-Juan Wang, Chun-Mei Zhou, Hao Yu, Feng Peng, Jin-Kun Fang Feb 2007

Mwnts Modified Gc Electrode For Hydrogen Peroxide Determination, Hong-Juan Wang, Chun-Mei Zhou, Hao Yu, Feng Peng, Jin-Kun Fang

Journal of Electrochemistry

A MWNTs modified GC electrode was constructed successfully to be used to detect hydrogen peroxide.Two methods of maximum anodic current of cyclic voltommogram and chronoamperometry were adopted to measure the concentration of hydrogen peroxide.The results show that the MWCNTs can enlarge the effective surface area of GC electrode and can enormously enhance the electron transfer.The sensitivity and correlation coefficient for hydrogen peroxide detection are 2.84 μA/mmol·L-1,0.997 and 1.5 μA/mmol·L-1,0.971 for cyclic voltammetry and chronoamperometry,respectively.The procedure of the two methods to detect hydrogen peroxide is simple,and the results obtained are satisfied.

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Influence Of Electrolyte On The Preparation And Electrocatalytic Properties Of Pt/Gc Electrodes, Sheng-Pei Chen, Yan-Xin Chen, Tao Huang, Xiao-Wen Hou, Shi-Gang Sun Feb 2007

Influence Of Electrolyte On The Preparation And Electrocatalytic Properties Of Pt/Gc Electrodes, Sheng-Pei Chen, Yan-Xin Chen, Tao Huang, Xiao-Wen Hou, Shi-Gang Sun

Journal of Electrochemistry

Influence of electrolyte on the electrocatalytic properties of Pt/GC electrodes for formic acid oxidation were studied by using cyclic voltammetry, SEM and electrochemical in situ FTIR spectroscopy. It has demonstrated that the surfaces of Pt/GC electrodes prepared in H2SO4 (Pt/GC1) or in HClO4(Pt/GC2) are all composed of platinum particles, but which crystals are some differences in size and shape.Diameters of platinum particles on the surface Pt/GC1 are of 100~200 nm, and with spheral shape in the majority. The sizes of platinum particles on the Pt/GC2 electrode are larger in general,part of particles is of cube …

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Polarization Properties Of The Cu/Paa Composite Films, Li-Chun Zhang, Qing-Shan Li, Meng-Meng Zheng, Fu-Quan Wu Feb 2007

Polarization Properties Of The Cu/Paa Composite Films, Li-Chun Zhang, Qing-Shan Li, Meng-Meng Zheng, Fu-Quan Wu

Journal of Electrochemistry

Porous alumina templates with different apertures were fabricated by the pore widening and increase of the anodic oxidation voltage,and then Cu nanowires were synthesized in porous alumina templates by alternating electro-deposition method.The transmission spectrum and polarization spectrum of Cu/PAA composite films were measured.Experiment have indicated that both the pore widening and increase the anodic oxidation voltage can make the transmittance drop,but the pore widening cannot enhance the polarization performance of the micropolarizer.The extinction ratio can be improved with increase of the template oxidation voltage or the Cu nanowires' diameter.

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Preparation And Lithium Storage Performance Of Nano-Structural Sno2/Carbon Nanotubes Composite Electrodes, Hong-Bing Wei, Ling Huang, Xiao-Bin Wu, Fu-Sheng Ke, Jin-Shu Cai, Xiao-Yong Fan, Fang-Zu Yang, Shi-Gang Sun Feb 2007

Preparation And Lithium Storage Performance Of Nano-Structural Sno2/Carbon Nanotubes Composite Electrodes, Hong-Bing Wei, Ling Huang, Xiao-Bin Wu, Fu-Sheng Ke, Jin-Shu Cai, Xiao-Yong Fan, Fang-Zu Yang, Shi-Gang Sun

Journal of Electrochemistry

The Nano-structural SnO2/Carbon Nanotubes Composites were prepared in a solution of SnCl2,ethylene glycol(EG),purified MWCNTs and sodium dodecyl sulfate(SDS) at 160 ℃.The phase structure and surface morphology of the composites were measured by XRD HRTEM and SEM.The results indicate that there are high dispersions and high loadings of SnO2 nanoparticles on MWCNTs.Electrochemical lithium storage performance was studied preliminarily on the obtained samples.MWCNTs modified with SnO2 nanoparicles were shown to have a higher electrochemical reversible capacity than that of MWCNTs during the charge and discharge process.MWCNTs can accommodate the larger structure strain of the active materials …

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Study On The Electrochemical Machining Of Titanium Alloys Tc4 With The Method Of Uniform Design, Mei-Li Zhang, Di Zhu, Zheng-Yang Xu Feb 2007

Study On The Electrochemical Machining Of Titanium Alloys Tc4 With The Method Of Uniform Design, Mei-Li Zhang, Di Zhu, Zheng-Yang Xu

Journal of Electrochemistry

For the electrochemical machining of titanium alloys,a passivating film tends to form on the machining surface,which holdbacks the process of machining;and some corrosive pittings can appear on the non-machining surface,which leading to the poor surface quality.So how to improve the machining surface quality,this is a hot problem in aerospace industries.An experiment plan has been made with the method of uniform design and the variance analysis has been carried out using the result data of the previous experiments.The experimental results show that an excellent machining surface with Ra 0.38 μm would be obtained in the electrolyte of 10% NaCl solution,4% Na …

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Electrochemical Characteristics Of La0.7-XCeXMg0.3Ni2.4Co0.6(X=0～0.4) Hydrogen Storage Alloys, Ling-Ling Xiao, Yi-Jing Wang, Yi Liu, Jian-Sheng Cao, Da-Wei Song, Li-Fang Jiao, Hua-Tang Yuan Feb 2007

Electrochemical Characteristics Of La0.7-XCeXMg0.3Ni2.4Co0.6(X=0～0.4) Hydrogen Storage Alloys, Ling-Ling Xiao, Yi-Jing Wang, Yi Liu, Jian-Sheng Cao, Da-Wei Song, Li-Fang Jiao, Hua-Tang Yuan

Journal of Electrochemistry

The effect of partial substitution of Ce for La on the structure and the electrochemical properties of the La0.7-xCexMg0.3Ni2.4Co0.6(x=0～0.4)hydrogen storage alloys have been investigated systematically.The result of X-ray powder diffraction(XRD) show that the alloys are all consisted of the LaNi3 phase and the LaNi5 phase.The maximum discharge capacity is decreased gradually with increase of the Ce contents,but the cycling life is improved obviously.

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Fabrication And Performance Of Ni-Scsz Cermet Anode Modified By Coating With Gd0.2Ce0.8O2 For A Sofc, Ren-Zhu Liu, Bo Huang, Xiao-Feng Ye, Shao-Rong Wang, Jia-Di Cao, Huai-Wen Nie, Ting-Lian Wen Feb 2007

Fabrication And Performance Of Ni-Scsz Cermet Anode Modified By Coating With Gd0.2Ce0.8O2 For A Sofc, Ren-Zhu Liu, Bo Huang, Xiao-Feng Ye, Shao-Rong Wang, Jia-Di Cao, Huai-Wen Nie, Ting-Lian Wen

Journal of Electrochemistry

A Ni-scandia-stabilized zirconia(Ni-ScSZ) cermet anode modified by coating with nano-sized gadolinium-doped ceria(GDC,Gd0.2Ce0.8O2) was prepared using a simple combustion process for the solid oxide fuel cell(SOFC) running on methane fuel. X-ray diffraction(XRD) and scanning electron microscopy(SEM) indicated that the surface of Ni-ScSZ was coated by nano-sized GDC particles(<100nm). Single cell testing showed that the 2.0%(by mass) GDC-coated Ni-ScSZ anode had better performance. The highest power densities of the cell with this anode were 825 and 848mW/cm2 at 850℃ in humidified hydrogen and methane, respectively, whereas the corresponding values were 584 and 586mW/cm2 for the cell with Ni-ScSZ anode.Electrochemical impedance spectra(EIS) illustrated that the cell with Ni-ScSZ anode exhibited far greater impedances than the cell with 2.0%(by mass) GDC-coated Ni-ScSZ anode.Then the …

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Trisodium Dicalcium Bismuth Hexaoxide, Irina V. Puzdrjakova, Rene B. Macquart, Mark D. Smith, Hans-Conrad Zur Loye Feb 2007

Trisodium Dicalcium Bismuth Hexaoxide, Irina V. Puzdrjakova, Rene B. Macquart, Mark D. Smith, Hans-Conrad Zur Loye

Faculty Publications

Single crystals of the title compound, Na3Ca2BiO6, were grown from a high-temperature reactive flux solution of Na2CO3. Na3Ca2BiO6 crystallizes as an ordered rock-salt structure (space group Fddd), in which the octahedral holes in the oxide array are filled by an ordered 3:2:1 arrangement of Na+, Ca2+ and Bi5+ cations. All atoms except for one O atom lie on special positions; site symmetries are as follows: Bi 222, Ca 2, Na 222 and 2, O 2.

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Effect Of 2,2'-Dipyridyldipyridyl And K4Fe(Cn)6 On Electroless Copper Plating Using Glyoxylic Acid As Reducing Agent, Dan-Dan Shen, Fang-Zu Yang, Hui-Huang Wu Feb 2007

Effect Of 2,2'-Dipyridyldipyridyl And K4Fe(Cn)6 On Electroless Copper Plating Using Glyoxylic Acid As Reducing Agent, Dan-Dan Shen, Fang-Zu Yang, Hui-Huang Wu

Journal of Electrochemistry

The electroless copper plating was studied in a bath consisting of glyoxylic acid as reducing agent,Na2EDTA as complexing agent,both 2,2'-dipyridyl and K4Fe(CN)6 as additives,focused on the influence of the additives on the deposition rate,as well as on the composition,structures and surface morphology of the deposits.It was found that adding an optimum amount of 2,2'-dipyridyl and K4Fe(CN)6 to the bath will not only improve the stability of the bath,but also increase the deposition rate by 100 %.The simultaneous addition of both additives causes the deposits to bright appearance and the change in morphology.The …

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The Influence Of Electrolytic Conditions On Synthesis Of Feo42-, Yan Zhou, Wei-Hua Yang, Dong-Qin Bi, Ting-Ting Huang, Zhen Sun, Quan-Feng Guo Feb 2007

The Influence Of Electrolytic Conditions On Synthesis Of Feo42-, Yan Zhou, Wei-Hua Yang, Dong-Qin Bi, Ting-Ting Huang, Zhen Sun, Quan-Feng Guo

Journal of Electrochemistry

The FeO42-was synthesized using iron lattice as anode and the solid K2FeO4 was also prepared.Influence of electrolytic conditions,such as stir,ultrasonic,temperature and current density on the current efficiency were studied.The results showed that preferable ferrate(VI) current yield was obtained in a current density of 10 mA·cm-2,temperature 30 ℃ and 14 mol/L NaOH as electrolyte under at stirring effect.

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Variable Frequence Switching Power Supply Used To Aluminum Foil Corrosion, Xiang-Dong Zhuo, Lan Sun, Guo-Qing Qian, Chang-Jian Lin Feb 2007

Variable Frequence Switching Power Supply Used To Aluminum Foil Corrosion, Xiang-Dong Zhuo, Lan Sun, Guo-Qing Qian, Chang-Jian Lin

Journal of Electrochemistry

A new variable frequence and multi-wave power supply used to aluminum foil corrosion is introduced. The switching supply power supply controlled by the microcontroller and Variable Frequence in low band and multi-wave, big power supply controlled by the electronic switch bridge for changing phase were designed. This power supply does not need bulky and cumbersome transformer, and the frequency at lower limit is not limited, even lower than 1Hz.

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Study On The Electrochemical Enhanced Self-Assembled Cobalt-Porphyrin Monolayer, Bei Zhang, Rong Wang, Guo-Yang Zhu, Xiaowei Cao, Xia-Qin Wu, Zong-Rang Zhang, Takeo Ohsaka Feb 2007

Study On The Electrochemical Enhanced Self-Assembled Cobalt-Porphyrin Monolayer, Bei Zhang, Rong Wang, Guo-Yang Zhu, Xiaowei Cao, Xia-Qin Wu, Zong-Rang Zhang, Takeo Ohsaka

Journal of Electrochemistry

According to the different coordination ability between Cobalt(II) porphyrin and Cobalt(Ⅲ) porphyrin,an electrochemical modulated self-assembling process was developed to prepare the CoTMPP/MP/Au(E) modified electrode. The O2 reduction catalytic activity and the Raman spectrum of the CoTMPP/MP/Au(E) modified electrode were found to be similar to those of the CoTMPP/MP/Au(I) modified electrode obtained by the immersion method, which was suggested that both modified electrodes have the similar well oriented structure and electrochemical behavior. Compared with CoTMPP/Au modified electrode, the modified electrodes with mercaptopyridine ligand were showed better electrocatalytic activity and stability.

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Investigations On Edlcs Using Pmma-Based Gel Polymer Electrolytes, Xiang-Li Meng, Jin-Ling Yin, Juan Ren, Bao-Hong Zhang Feb 2007

Investigations On Edlcs Using Pmma-Based Gel Polymer Electrolytes, Xiang-Li Meng, Jin-Ling Yin, Juan Ren, Bao-Hong Zhang

Journal of Electrochemistry

Polymethyl methacrylate(PMMA) based gel polymer electrolytes electrochemical double layer capacitors(GPE-EDLCs) were fabricated by an in situ polymerisatonal method with actived carbon electrodes,using propylene carbonate(PC) and ethylene carbonate(EC) as plasticizer,lithion perchlorate as surporting electrolytes.The ion conductivity values of GPEs were evaluated by AC impedance.The properties of PMMA-based GPEs capacitors were researched by impedance spectrum,cyclic voltammetry,galvanostatic charge-discharge.It showed that the ion conductivities of the PMMA-based gel polymer electrolytes reached to 3.7 mS·cm-1 at ambient tempreture.The working voltage of the capacitors reached to 3.0 V.The specific capacitance of the capacitor was obtained as high as 41.6 F·g-1(I=1 mA·cm-2).The …

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Quantized Magnetoresistance In Atomic-Size Contacts, Andrei Sokolov, Chunjuan Zhang, Evgeny Y. Tsymbal, Jody G. Redepenning, Bernard Doudin Feb 2007

Quantized Magnetoresistance In Atomic-Size Contacts, Andrei Sokolov, Chunjuan Zhang, Evgeny Y. Tsymbal, Jody G. Redepenning, Bernard Doudin

Jody Redepenning Publications

When the dimensions of a metallic conductor are reduced so that they become comparable to the de Broglie wavelengths of the conduction electrons, the absence of scattering results in ballistic electron transport and the conductance becomes quantized. In ferromagnetic metals, the spin angular momentum of the electrons results in spin-dependent conductance quantization and various unusual magnetoresistive phenomena. Theorists have predicted a related phenomenon known as ballistic anisotropic magnetoresistance (BAMR). Here we report the first experimental evidence for BAMR by observing a stepwise variation in the ballistic conductance of cobalt nanocontacts as the direction of an applied magnetic field is varied. …

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A Coarse Grain Model For Dna, Thomas A. Knotts Iv, Nitin Rathore, David C. Schwartz, Juan J. De Pablo Feb 2007

A Coarse Grain Model For Dna, Thomas A. Knotts Iv, Nitin Rathore, David C. Schwartz, Juan J. De Pablo

Faculty Publications

Understanding the behavior of DNA at the molecular level is of considerable fundamental and engineering importance. While adequate representations of DNA exist at the atomic and continuum level, there is a relative lack of models capable of describing the behavior of DNA at mesoscopic length scales. We present a mesoscale model of DNA that reduces the complexity of a nucleotide to three interactions sites, one each for the phosphate, sugar, and base, thereby rendering the investigation of DNA up to a few microns in length computationally tractable. The charges on these sites are considered explicitly. The model is parametrized using …

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Role Of Carbonate In The Cytotoxicity Of Carboplatin, Anthony J. Di Pasqua, Jerry Goodisman, Deborah J. Kerwood, Bonnie B. Toms, Ronald L. Dubowy Feb 2007

Role Of Carbonate In The Cytotoxicity Of Carboplatin, Anthony J. Di Pasqua, Jerry Goodisman, Deborah J. Kerwood, Bonnie B. Toms, Ronald L. Dubowy

Chemistry - All Scholarship

Carboplatin, [Pt(NH3)2(CBDCA-O,O')], 1, where CBDCA is cyclobutane-1,1-dicarboxylate, is used against ovarian, lung, and other types of cancer. We recently showed (Di Pasqua et al. (2006) Chem. Res. Toxicol. 19, 139-149) that carboplatin reacts with carbonate under conditions that simulate therapy to produce carbonato carboplatin, cis-[Pt(NH3)2(O-CBDCA)(CO3)]2-, 2. We use 13C and 1H NMR and UV-visible absorption spectroscopy to show that solutions containing carboplatin that have been aged in carbonate buffer under various conditions contain 1, 2, and other compounds. We then show that aging carboplatin in carbonate produces compounds that are more toxic to human neuroblastoma (SK-N-SH), proximal renal tubule (HK-2) …

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A Bridge To Coordination Isomer Selection In Lanthanide(Iii) Dota-Tetraamide Complexes, Jeff Vipond, Mark Woods, Piyu Zhao, Gyula Tircsó, Jimin Ren, Simon G. Bott, Doug Ogrin, Garry Kiefer, Zoltan Kovacs, A. Dean Sherry Feb 2007

A Bridge To Coordination Isomer Selection In Lanthanide(Iii) Dota-Tetraamide Complexes, Jeff Vipond, Mark Woods, Piyu Zhao, Gyula Tircsó, Jimin Ren, Simon G. Bott, Doug Ogrin, Garry Kiefer, Zoltan Kovacs, A. Dean Sherry

Chemistry Faculty Publications and Presentations

Interest in macrocyclic lanthanide complexes such as DOTA is driven largely through interest in their use as contrast agents for MRI. The lanthanide tetraamide derivatives of DOTA have shown considerable promise as PARACEST agents, taking advantage of the slow water exchange kinetics of this class of complex. We postulated that water exchange in these tetraamide complexes could be slowed even further by introducing a group to sterically encumber the space above the water coordination site, thereby hindering the departure and approach of water molecules to the complex. The ligand 8O2-bridged-DOTAM was synthesized in a 34% yield from cyclen. …

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Poly[Diaqua(Μ4-3-Fluorophthalato-Κ4O:O:O':O'')Cadmium(Ii)], Diana Rishmawi, Katie Lewis, Mark D. Smith, Leroy Peterson Jr., Hans-Conrad Zur Loye Feb 2007

Poly[Diaqua(Μ4-3-Fluorophthalato-Κ4O:O:O':O'')Cadmium(Ii)], Diana Rishmawi, Katie Lewis, Mark D. Smith, Leroy Peterson Jr., Hans-Conrad Zur Loye

Faculty Publications

The crystal structure of the title compound, [Cd(C8H3FO4)(H2O)2]n, consists of polymeric sheets formed by the bridging of octahedrally coordinated CdII by carboxylate O atoms of the 3-fluorophthalate (3-fpt2-) ligand. The layers exhibit hydrogen bonding between each of two coordinated water molecules and two O atoms of the ligand. Adjacent sheets are connected through - interactions.

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