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Surface Modifications Of Carbon Materials Used As Anode Of Lithium Ion Battery Ⅱ. The Carbon Material With Core Shell Structure And Its Positive Effect On Cell Performance Of Graphite Anode, Shuhua Ma, Hanju Guo, Ji Li, Hongze Liang, Xiabin Jing, Fosong Wang

Journal of Electrochemistry

The carbon powders and film electrode with core shell structure were prepared by carbonization in gas state with using refined coal as shell material and Artificial Graphite and Mesocarbon Microbeads (2 800 ℃) graphite as core material. Galvanostatic charge/discharge measurement showed that both steady charge/discharge capacity and first charge/discharge efficiency were improved. Cyclic voltammetry indicated that the peak at about 0.7 V vs. Li⁺/Li characteristic of decomposition of electrolyte got weakened, and a more compact film was formed. X-ray diffraction measurement suggested the existence of amorphous carbon shell on the carbon powders and carbon film.

Status Of Electroplated And Electroless Plated Thin Film Media For Magnetic Recording, Maozhong An, Zhelong Yang, Jingshuang Zhang, Zhenmi Tu

Journal of Electrochemistry

The current study situation for the magnetic recording media films produced by electroplating and electroless plating at aboard was summarized. The bath composition and operating conditions, the properties of the films were introduced. The problem to be solved for extending application of the films was suggested and thd further development was expected.

A Study On The Electrodeposition Of Palladium And It's Nucleation, Fangzu Yang, Shukai Xu, Shibing Yao, Bingyi Chen, Xueqing Zheng, Xiaohui Zhong, Shaomin Zhou

Journal of Electrochemistry

The electrodeposition and nucleation of palladium are studied in the system of potassium citrate and ammonium oxalate. The results show that, with the additives of XP-4 and XP-7 prepared in our laboratory, a full bright palladium electrodeposits will be obtained in the wide ranges of the cathode current densities 0.5～3.5 A/dm² and temperature 40～60 ℃; the qualities of the thick deposits will be effectively improved by means of pulse current plating. Cyclic voltammograms results show that the division of peaks between anodic and cathodic on the electrode process of palladium will be up to 1.05 V, which shows the …

The Adsorption-Desorption Behaviors Of Β Phenylaminopropiophenone On Iron In Sulphuric Acid Solution, Xianzhang Bu, Dihua Wang, Jinyun Zou, Fuxing Gan

Journal of Electrochemistry

The adsorption-desorption behaviors of β-phenylaminopropiophenone (PAP) on iron in 0.5 mol·L^-1 H₂SO₄ solution with or without halide ions (Cl^-, I^-) were investigated by potentiostatic polarization measurement. The results show that the adsorption of PAP on iron surface follows Flory-Huggins isotherm, the adsorption free energy parameter (f) is positive in H₂SO₄ solution; In the presence of 0.1 mol·L^-1 Cl^-1, when C_PAP ≤ 2×10^-5 mol·L^-1, f＞0. A desorption phenomenon was observed at more positive potential region in anodic polarization curves. Furthermore, the anodic desorption …

Studies On An Iron Heteropolyacid Redox Flow Battery, Peiju Sun, Wansheng You, Zhorgyin Tan

Journal of Electrochemistry

This paper reports a new Fe-HP redox flow cell. The positive and negative electrodes active materials are phosphomolybdic acid and acidified ferrous sulphate solutions respectively. Two activated porous carbon felt electrodes where the electrochemical reactions take place, are separated by a selective cation exchange membrane. The both couples have a suitable electrochemical reversibility on carbon and graphite electrodes. The active materials of the cell have very high stability. Moreover the cell has no life cycle limiting.

Problems Of The Study Of Anodic Films On Pb In Sulfuric Acid Solution (Ⅲ), Houtian Liu, Qunzhou Wang, Weifang Zhou, Wenbin Cai

Journal of Electrochemistry

The interstitial liquid among the particles in anodic Pb(Ⅱ) films could be the major passage for ion transportation. This is discussed with the mechanism of the cathodic reduction of anodic PbSO₄ film and the effect of Sb on the growth of anodic Pb(Ⅱ) oxides film.

Electrochemical Behaviors Of Isoalloxazine Confined In Montomorillonite Olay Modified Electrode, Zhibin Wu, Yuan Lin, Daodao Zhang, Haoqin Wu

Journal of Electrochemistry

A cyclic voltametric investigation of stability and redox properties of isoalloxazne on cetytrimethyammonium bromide (CTAB) modified montomorillonite clay platinium electrode in aqueous solution has been performed. pH dependent film concentrations and apparent diffusion coefficents were measured. The mechanism of the charge transport process with in the clay film were discussed.

Study On The Electrochemical Behavior Of Glycyrrhizic Acid, Chunming Wang, Yanrong Zhang, Hulin Li

Journal of Electrochemistry

The electrochemical response characteristics of glycyrrhizic acid (GA) on the mercury electrode are described. In Britton Robinson buffer, the cyclic voltammograms exhibit two reduction peaks at a potential range of -0.80～-1.60 V. The peak potentials and currents change significantly when solution pH changes. By means of ultraviolet abosrption method, it is proved that the reduction position of GA molecular is ketenes radical. The peak potentials move positively with increasing pH demonstrate that the primary electrode reaction is accompanied by a coupled chemical reaction.The electrode reaction process is a typical example of ECE mechanism. Some effects of various parameters on adsorptive …

Studies On The Cathodic Current Efficiency In The Electrodeposition Ni-Psz Gradient Coating, Jun Li, Dianlong Wang, Li Chen, Xinguo Hu

Journal of Electrochemistry

The cathodic current efficiency and the electrochemical behavior in electrodeposition Ni-PSZ gradient coating were investigated by various electrochemical techniques and scanning electron microscope. The results showed that the Ni-PSZ composite coatings can accelerate evolution of hydrogen with the increase of PSZ content. The overpotential of nickel reduction will be increased and that of hydrogen reaction will be reduced in the presence of PSZ particles in electrolyte. The effect of PSZ particles on nickel electrodeposition was preferentially to catalyze the formation of H ads . These all contributed to the lower current efficiency.

Study On Properties Of Magnesium Alloy Electrode With Anodized Film, Yi Chi, Ping Yang, Xiufeng Lin

Journal of Electrochemistry

The corrosion resistance of Mg alloy electrode with anodized film in atmosphere is bigger than that of the Mg alloy electrode with chromate film. The corrosion resisance and voltage delay of such electrode with anodized film in NaCl solution changed with anodizing comdition. The effects of composition, morphology and thickness of the anodized film on the peoperty of Mg alloy electrode are discussed.

Co-Wc Composite Elecrode, Zeshan Zhu, Xiufeng Xiao, Rongfang Liu, Jingying Shi

Journal of Electrochemistry

Electrodepositing Co-WC composite coatings from cobalt electro bath including WC particles was studied. WC particles accelerate the cathode reaction of composie electrodeposition. In alkaline solution the electrocatalytic properties of evoluting hydrogen were investigated. The results show that the properties of electrode remain superior and stable in a long term interval electrolyzing experiment.

Vapor–Liquid Coexistence Of Quasi-Two-Dimensional Stockmayer Fluids, G.T. Gao, Xiao Cheng Zeng, Wenchuan Wang

Xiao Cheng Zeng Publications

A quasi-two-dimensional (2D) Stockmayer model is developed in which the center of mass of the molecule is confined on a plane while the dipole of the molecule can rotate freely in three dimensional space. This model entails essential characteristics of systems such as dipolar molecules physisorbed on a solid surface, or a Langmuir monolayer consisting of short-chain molecules with a dipolar tail. The Gibbs ensemble Monte Carlo technique is employed to determine the vapor– liquid equilibria of the model fluids. An Ewald sum for this quasi-2D model is formulated to account for the long-range dipolar interactions. Three systems with different …

The Hydroperoxyl Radical Dimer: Triplet Ring Or Singlet String?, Justin T. Fermann, Brian C. Huffman, Gregory S. Tschumper, Henry F. Schaefer

Chemistry Faculty Research & Creative Works

In order to determine the lowest energy isomer of the hydroperoxyl radical dimer, H2O4, ab initio quantum mechanical methods were employed to predict the geometrical structures, relative energies, harmonic vibrational frequencies, and associated IR intensities of both open chain and cyclic isomers. Two minima were located on the open chain potential energy surface, one of C2 symmetry and one of C1 symmetry. The relative energies of the different H₂O₄ structures vary strongly with level of theory. The most reliable treatment used in the present study predicted that the global minimum is the closed-shell C1 chain isomer which …

Partitioning Of The Reactive Nitrogen Reservoir In The Lower Sratosphere Of The Southern Hemisphere: Observations And Modeling, R. S. Gao, D. W. Fahey, R. J. Salawitch, S. A. Lloyd, D. E. Anderson, R. Demajistre, C. T. Mcelroy, E. L. Woodbridge, R. C. Wamsley, S. G. Donnelly, L. A. Del Negro, M. H. Proffitt, R. M. Stimpfle, D. W. Kohn, S. R. Kawa, L. R. Lait, M. Loewenstein, J. R. Podolske, E. R. Keim, J. E. Dye, J. C. Wilson, K. R. Chan

Chemistry Faculty Publications

Measurements of nitric oxide (NO), nitrogen dioxide (NO2), and total reactive nitrogen (NOy = NO + NO2 + NO3 + HNO3 + ClONO2 + 2N2O5 + ...) were made during austral fall, winter, and spring 1994 as part of the NASA Airborne Southern Hemisphere Ozone Experiment/Measurements for Assessing the Effects of Stratospheric Aircraft mission. Comparisons between measured NO2 values and those calculated using a steady state (SS) approximation are presented for flights at mid and high latitudes. The SS results agree with the measurements to within 8%, suggesting that the kinetic rate coefficients and calculated NO2 photolysis rate used in …

Reactions Of Hydroxylamine With Metal Porphyrins, In Kyu Choi, Yanming Liu, Zhongcheng Wei, Michael D. Ryan

Chemistry Faculty Research and Publications

The reaction of hydroxylamine with a series of metal porphyrins was examined in methanol/chloroform media. The reductive nitrosylation reaction was observed for the manganese and iron porphyrins, leading to a nitrosyl complex that precipitated out of the solution in good isolatable yield (80−90%). This reaction could be used synthetically for the generation of iron and manganese porphyrin nitrosyl complexes and was particularly useful for making isotopically labeled nitrosyl complexes. On the other hand, Co^II(TPP) and Cr(TPP)(Cl) did not react with hydroxylamine under anaerobic conditions. With trace amounts of oxygen, the reaction of Co^II(TPP) with hydroxylamine led …

Quantitation Of Ethidium-Stained Closed Circular Dna In Agarose Gels, Michael F. Shubsda, Jerry Goodisman, James C. Dabrowiak

Chemistry - All Scholarship

The fluorescence of ethidium bromide (EB) bound to equimolar amounts of supercoiled form I and unstrained linear form III pBR322, SV40 and PM2 DNA in agarose gels has been measured by scanning a photographic negative of the gel with a microdensitometer. For SV40 and PM2 DNA, commonly used staining conditions cause both forms, i.e. linear and supercoiled, to fluoresce to the same extent. This obviates the need to use a correction factor for the fluorescence of form I DNA when measuring the amount of this form relative to the amounts of unstrained forms in agarose gels. In the case of …

Monte Carlo Simulation Of The Solid To Superliquid Phase Transition Of Langmuir Monolayers. Ii. Characteristics Of Phase Transition, M.D. Gibson, D.R. Swanson, Craig J. Eckhardt, Xiao Cheng Zeng

Craig J. Eckhardt Publications

The restricted-to-free rotator phase transition of fatty acid monolayers has been modeled using a potential which represents the amphiphiles as planar cross sections of fourfold symmetry. Using much larger system sizes than paper I [D. R. Swanson, R. J. Hardy, and C. J. Eckhardt, J. Chem. Phys. 99, 8194 (1993)], Monte Carlo simulations of the isobaric–isothermal ensemble of model systems with varied number of objects were undertaken to study the effect of system size on the characteristics and order of the phase transition. A peak in the specific heat vs temperature curve was observed near the transition. For each system …

Conformations And Relative Stabilities Of The Cis And Trans Isomers In A Series Of Isolated N-Phenylamides, V. P. Manea, K. J. Wilson, John R. Cable

Chemistry Faculty Publications

The gas-phase conformations of a series of isolated N-phenylamides have been determined from vibrationally resolved electronic spectra obtained by resonant two-photon ionization in a supersonic jet expansion. Both the cis and trans isomers of formanilide were identified, with the cis isomer in 6.5% abundance. The spectral features displayed by this isomer are consistent with a nonplanar geometry which undergoes a large change in the phenyl torsional angle following electronic excitation. The more abundant trans isomer of formanilide adopts a planar structure and is stabilized by 2.5 kcal/mol with respect to the cis isomer. In the excited electronic state the relative …

Oxidized Sterols In Patients With Diabetic Heart Disease And Microwave-Mediated Stereoselective Synthesis Of 3-Keto Cholesterol And Cholesterol Epoxide, Cholesteryl Ester Epoxides, Meenakashi N. Kothavale

Theses

Oxidized low density lipoproteins (ox-LDL) may play important role in mediating hypercholesterolemic endothelial dysfunction. The uptake of modified LDL by macrophages to form foam cells has been implicated in the enhancement of atherosclerosis. Recent reports have suggested that when LDL undergoes oxidation in vitro , it is accompanied by a substantial loss of free and esterified cholesterol leading to the formation of oxidation products of cholesterol ( oxysterols). These compounds are present in human atherosclerotic plaques and in human foam cells.

In this regard we have recently studied the plasma sterol composition in diabetic heart patients We have found cholesterol …

Catalytic Control Of Nitric Oxide With Gaseous Or Solid Reducing Materials, Xiaoyong Tang

Theses

Air pollution from mobile sources is an increasingly serious problem throughout most of the industrialized would. Diesel powered vehicles, because of their higher thermal efficiency, tend to emit less carbon monoxide and unburned hydrocarbons than gasoline vehicles, but emit significant quantities of NO_x. Therefore, it is essential to develop improved emission control equipment in diesel engines. A fixed bed catalytic reactor was used to study the decomposition of NO and the reduction of NO to N₂ by different reductants that can be found in diesel exhaust, such as hydrocarbons, CO and elemental carbon over different catalysts. The …

Chiral Separation Of Monoterpenes Using Mixtures Of Sulfated Β-Cyclodextrins And Α-Cyclodextrin As Chiral Additives In The Reversed-Polarity Capillary Electrophoresis Mode, Kyung Hyun Gahm, Lisa W. Chang, Daniel W. Armstrong

Chemistry Faculty Research & Creative Works

The use of mixtures of sulfated β-cyclodextrins and native α-cyclodextrin as chiral additives in capillary electrophoresis was evaluated for the chiral resolution of neutral, cyclic and bicyclic monoterpenes, including α-pinene, (β-pinene, camphene and limonene. Binding properties of sulfated β-cyclodextrins towards these monoterpenes were studied. It was found that there was no enantioresolution of these terpenoids over the concentration range studied. However, the addition of α-cyclodextrin to the running electrolyte in addition to 6.5 mM sulfated β-cyclodextrins, imparted differences in the mobilities of the terpenoid enantiomers and resulted in remarkable enantiomeric separations of α-pinene (R(s)=25), β-pinene (R(s)=12), camphene (R(s)=12) and limonene …

Nucleotide Or Nucleoside Photoaffinity Compound Modified Antibodies, Methods For Their Manufacture And Use Thereof As Diagnostics And Therapeutics, Boyd E. Haley, Heinz Köhler, Krishnan Rajagopalan, Gabriela Pavlinkova

Chemistry Faculty Patents

Sites on antibodies having affinity for photoaffinity compounds, in particular purine or azidopurine containing compounds are taught. These sites provide for the site-specific attachment of nucleotide photoaffinity compounds to antibodies, e.g., ATP- or GTP-analog photoaffinity compounds by photochemical reaction. These nucleotide photoaffinity compounds may additionally be attached to molecules having a desired therapeutic or diagnostic activity, and the resultant conjugates used as diagnostics or therapeutics.

Enhancing The Performance Of Membrane Introduction Mass Spectrometry By Organic Carrier And Liquid Chromatographic Separation, Shi Ouyang, Yong Hong Chen, Yan Xu

Chemistry Faculty Publications

A method of membrane introduction mass spectrometry with liquid chromatographic separation (LC/MIMS) for the analysis of volatile organic compounds (VOCs) in water has been developed. The method not only inherited all the advantages of membrane introduction mass spectrometry by flow-injection analysis (FIA/MIMS), but also expanded the application of MIMS to the determination of compounds with identical quantitation ions. Because the quantitation by LC/MIMS is based on two-dimensional identification (retention time (tr) and mass-to-charge ratio ()), it provides a tangible approach to the analysis of VOCs in complex aqueous samples. In this work, a C18 column and a mobile phase (methanol/water) …

Synthetic Strategies For The Construction Of Enantiomeric Azanoradamantanes, Daniel Becker, Roger Nosal, Daniel L. Zabrowski, Daniel Flynn

Chemistry: Faculty Publications and Other Works

The amino azanoradamantane hexahydro-2,5b-methano-IH-3aS,3aa,6aa-cyclopenta-[clpyrrole-4a-amine 1and the corresponding enantiomer ent-1 have been prepared along with benzamide derivatives SC-52491and SC-52490, respectively, which are of pharmaceutical interest. The key meso-azabicyclo[3.3.0] intermediate 3 was prepared via three separate routes: a [3+2] cycloaddition route, a radical cyclization/ionic cyclization route, and a reductive Pauson-Khand route.

Identification Of The Adp-L-Glycero-D-Manno-Heptose-6-Epimerase (Rfad) And Heptosyltransferase Ii (Rfaf) Biosynthesis Genes From Nontypeable Haemophilus Influenzae 2019, W A. Nichols, B W. Gibson, William Melaugh, N G. Lee, M Sunshine, M A. Apicella

Chemistry Faculty Publications

Haemophilus influenzae is an important human pathogen. The lipooligosaccharide (LOS) of H. influenzae has been implicated as a virulence determinant. To better understand the assembly of LOS in nontypeable H. influenzae (NtHi), we have cloned and characterized the rfaD and rfaF genes of NtHi 2019, which encode the ADP-L-glycero-D-manno-heptose-6-epimerase and heptosyltransferase II enzymes, respectively. This cloning was accomplished by the complementation of Salmonella typhimurium lipopolysaccharide (LPS) biosynthesis gene mutants. These deep rough mutants are novobiocin susceptible until complemented with the appropriate gene. In this manner, we are able to use novobiocin resistance to select for specific NtHi LOS inner core …

Characterization Of A Transposon Tn916-Generated Mutant Of Haemophilus Ducreyi 35000 Defective In Lipooligosaccharide Biosynthesis, B W. Gibson, A A. Campagnari, William Melaugh, M A. Apicella, S Grass, Jing Wang, Katherine L. Palmer, R S. Munson

Chemistry Faculty Publications

To define the role of the surface lipooligosaccharide (LOS) of Haemophilus ducreyi in the pathogenesis of chancroid, Tn916 mutants of H. ducreyi 35000 defective in expression of the murine monoclonal antibody (MAb) 3F11 epitope on H. ducreyi LOS were identified by immunologic screening. One mutant, designated 1381, has an LOS which lacks the MAb 3F11 epitope and migrates with an increased mobility on sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The gene disrupted by the Tn916 element in strain 1381 was identified by cloning the sequences flanking the Tn916 element. The sequences were then used to probe a lambda DASHII genomic library. …

An Approach To A Generalized Synthesis For 2-Halo-1,1-Diarylalkenes, Cheryll R. Roberts

Theses, Dissertations and Capstones

This study was concerned with the development of a generalized synthesis of halogenated 1,1-diarylalkenes. The alkylation of 1,1-diphenylethylene was carried out by the addition of organolithium compounds (C Li, PhLi, t-BuLi, n-BuLi). N-bromo-succinimide (NBS) was used for bromination. The reaction forming triphenylbromo-ethylene gave the largest percent yield (93.6%). The reaction forming 2-bromo-3,3- dimethyl-l,l-dipheny1-1-butene resulted in a 38.1% yield. Each product structure was confirmed by proton and carbon-13 nuclear magnetic resonance, and infrared spectroscopy.

Determination Of Selected Hydrocarbon Concentrations In Reformate Using Near Infrared Spectroscopy, Roy Roger Bledsoe Jr.

Theses, Dissertations and Capstones

Near infrared spectroscopy was used as a quantitative technique employing multiple linear regression and partial least squares regression for determining the concentration of hydrocarbon groups and individual hydrocarbons present in reformate, a refinery process stream. Models were generated for total aromatics, benzene, toluene, total xylenes and individual xylene isomers, ethylbenzene, total paraffins, n-hexane, n-heptane, total isoparaffins, isopentane, 2-methylhexane, total naphthenes, methylcyclopentane, and total olefins. Some models are being used with an on-line instrument to constantly monitor a reformate stream as it leaves the reforming unit, with a standard error of performance of 0.118 volume percent for the prediction …

Directed Panspermia. 3. Strategies And Motivations For Seeding Star-Forming Clouds, Michael Noah Mautner

Chemistry Publications

Microbial swarms aimed at star-forming regions of interstellar clouds can seed stellar associations of 10 - 100 young planetary systems. Swarms of millimeter size, milligram packets can be launched by 35 cm solar sails at 5E-4 c, to penetrate interstellar clouds. Selective capture in high-density planetary accretion zones of densities > 1E-17 kg m-3 is achieved by viscous drag. Strategies are evaluated to seed dense cloud cores, or individual protostellar condensations, accretion disks or young planets therein. Targeting the Ophiuchus cloud is described as a model system. The biological content, dispersed in 30 μm, 1E-10 kg capsules of 1E6 freeze-dried microorganisms …

Kinetics Of Cleavage Of Intra- And Extracellular Simian Virus 40 Dna With The Enediyne Anticancer Drug C- 1027, Jerry Goodisman, James C. Dabrowiak, Christopher A. Kirk, Terry A. Beerman, Loretta S. Gawron

Chemistry - All Scholarship

A kinetic analysis of cleavage of simian virus DNA (SV40 DNA) inside and outside green monkey BSC-I cells by the enediyne-protein antibiotic C-1027 and its free chromophore is described. Information on rate constants was obtained by fitting populations of forms I (closed circular DNA), II (nicked circular DNA) and III (linear DNA) of SV4f.J DNA as a function of drug concentration to a kinetic model which includes: cutting of form I to give form II with rate constant k1. cutting of form I to give form III with rate constant k4, and cutting of form II to give form III …