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Articles 30451 - 30480 of 34557

Full-Text Articles in Physical Sciences and Mathematics

Theory Of Cyclic Voltammetry At Microdisk Electrode For Reversible Systems, Qiankun Zhuang, Hongyuan Chen Aug 1995

Theory Of Cyclic Voltammetry At Microdisk Electrode For Reversible Systems, Qiankun Zhuang, Hongyuan Chen

Journal of Electrochemistry

By means of a new approach,the current equations of cyclic voltammetry whichdescribes two cases of quasi-steady-state and fast linear scan at microdisk electrode for reversiblesystem were presented and verified experimentally. It has been shown that the features of this currentessentially depend on the ration of,which is described in detail.ln extreme cases, the equationsare the same as those listed in literat ures for large plane and spherical electrodes.Using the quasi-steady-state equation,the causes and conditions for forming steady state,quasi-steady state andhysteresis current for linear sweep voltammetry are all explained and discussed.The width of the″hysteresis ring″is also calculated in this work.And the results …

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Coadsorption Of Para-Toluene Sulfamide And 1.4-Butynediol At Mercury Electrode, Shukun Huang, Naixian Xie, De Gao, Qiang Liu Aug 1995

Coadsorption Of Para-Toluene Sulfamide And 1.4-Butynediol At Mercury Electrode, Shukun Huang, Naixian Xie, De Gao, Qiang Liu

Journal of Electrochemistry

The coadsorption characteristics of para-toluene sulfamide and 1,4-butynediol atmercury electrode have been studied by means of electrocapillary curve,differential capacity curve,Stuart model and the SCFMO method(CNDO/2).The coadsorption is a physical adsorption occuringnaturally. Lateral and flat orientations in the two adsorbates close to their maximum adsorptionpotential were considered respectively.Unlike attractive interactions of their own,there was arepulsive interaction at their coadsorption layer.A preferred adsorption of 1,4-butynediol occurredWhen they were at the same volume concentration.

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Development Of High Active Aluminum Alloy Sacrificail Anode, Zhaobo Wei, Jianhua Wu, Guangzhang Chen, Songrao Jiang Aug 1995

Development Of High Active Aluminum Alloy Sacrificail Anode, Zhaobo Wei, Jianhua Wu, Guangzhang Chen, Songrao Jiang

Journal of Electrochemistry

A high active aluminum alloy sacrificial anode with the operating potential-1.40 v (SCE),and the the current capacity more than 2 175 A·h/kg and dissolution fair issuccessfully developed by adding zinc,indium,gallium,bismuth and heat treatment.The aluminumalloy sacrificial anode with super electrochemical properties can throughly replace the magnesium alloyanode when applied to seawater and freshening seawater,which is obviously advantageous to thetechnology and economy.

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Studies On The Structure Of Licoo_2 Synthesized With Tartaric Acid And The Behaviorof Its Rechargeable Lithium Battery, Fuping Zhang Aug 1995

Studies On The Structure Of Licoo_2 Synthesized With Tartaric Acid And The Behaviorof Its Rechargeable Lithium Battery, Fuping Zhang

Journal of Electrochemistry

The structure of LiCoO_2 synthesized with tartaric acid and the behavior of itsrechargeable Lithium battery have been studied by XRD, XPS, CV. CT. It has been shown thatLiCoO_2 has a space group R3m with hexagonal parameters a=0.281 0 nm,c=1.408 8 nm. Low-spin state Co￣(3+) configuration in LiCoO_2 has been suggested. Also,Li_2O, was identified onits surface.Furthermore, the capacity and the middle working voltage of its Lithium battery are about 120 mA·h·g￣(-1) and 3.8 V,respectively.The EMF of the cell changes with the Lithium composition of itscathode following E=4.318-0.450 X￣(2/3) in 0.451≤X≤0.934.

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Photoelectric Property For Zinc Phthalocyanine Of Doping C_(60) On Inp Electrode, Mengxiong Zhan, Rongqing Yu, Biaolian Zhen, Dadian Cheng, Lansun Zheng Aug 1995

Photoelectric Property For Zinc Phthalocyanine Of Doping C_(60) On Inp Electrode, Mengxiong Zhan, Rongqing Yu, Biaolian Zhen, Dadian Cheng, Lansun Zheng

Journal of Electrochemistry

The curves of spectral and photovoltaic responses to zinc phthalocyanine of dopingC_(60) were determinted.The photovoltaic property for zinc phthalocyanine of doping C_(60) wereinvestigated on the InP single crystal in the photoelectrochemical cell.The results have shown that:1)The photovoltaic effect and the in tensit ies of the spectral response and of the photovoltaic responsefor ZnPc of doping C_(60) were greater than those of ZnPc;2)had better redox couple in the cells.

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Studies On The Bright Zinc-Nickel Alloy Palting In Alkaline Baths, Jiale Cai, Shaomin Zhou Aug 1995

Studies On The Bright Zinc-Nickel Alloy Palting In Alkaline Baths, Jiale Cai, Shaomin Zhou

Journal of Electrochemistry

The electrochemical properties of the Zn-Ni plating baths and the structure andperformance of the obtained deposits were investigated.The results show that the nickel content of theobtained deposits is incereased with decreasing of Zn￣(2+)/Ni￣(2+) ratio in the baths and with increasing ofcathodic current density;The cathode current efficiency is increased with increasing of Zn [Ⅱ]content in the bath and with decreasing of cathodic current density.The ZN-11 additive used is thereaction product of heterocyclic compound and polyamines with epichlorohydrin,it has a higheradsorptivity on Hg-electrede at potential between -0.16～-1.68 V (vs. Hg/HgO,1 mol·L￣(-1)KOH). It is found that zinc and nickel are codeposited anomalously due …

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Dielectric Relaxation Of Heterogeneous Systems With Planar Structure──Influence Of The Number And The Electric Conductivity Of Constituent Phases On The Relaxation Pattern, Kongshuang Zhao Aug 1995

Dielectric Relaxation Of Heterogeneous Systems With Planar Structure──Influence Of The Number And The Electric Conductivity Of Constituent Phases On The Relaxation Pattern, Kongshuang Zhao

Journal of Electrochemistry

Heterogeneous systems exhibit a marked dielectric relaxation at frequenciesbetween 0.1kHz and 10 MHz.In order to understand the reason for dielectric relaxation and therelation between the dielectric relaxation and the number of interfaces in heterogeneous systems,as anexample of typical heterogeneous systems、film-solution systems are discussed both theoretically andexperimentally from dielectric point of view.In particular,the frequency profiles of the dielectricrelaxation are analyzed in Connection with structure of the sustems and concentration of theconstituent phases.The reason for the relaxation is represented throrgh phenomenologically based onthe M-W mechanism.The feature of dielectric relaxation of these systems leads to the followhgcharacteristics:(1)The number of dielectric relaxations is equal …

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Study On The Surface States Of Zinc Sulfide Thin Film Doped With Erbium And Their Effect On The Relaxation Luminance, Yujiang Wang, Zhaohong Liu, Zhenxiang Chen Aug 1995

Study On The Surface States Of Zinc Sulfide Thin Film Doped With Erbium And Their Effect On The Relaxation Luminance, Yujiang Wang, Zhaohong Liu, Zhenxiang Chen

Journal of Electrochemistry

X-ray photoelectron spectrum and characteristics of the capacity,versus thevoltage of the thin film devices are measured to study the surface states of the zinc sulfide thin film.The transient electroluminescence excited by pulses shows the relaxation luminance peaks during anon-exponential decay process of the characteristic transitions activated by Er￣(3+) in the ZnS directcurrent thin film electroluminescence (DCTFEL) devices.The surface structures of ZnS:Cu,Cl,Erfilm with the absorption of oxygen,and the effect of the surface states on the relaxation luminance ofthe devices are discussed.

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Assessing The Evolutionary Nature Of Multifragment Decay, E. Cornell, T. M. Hamilton, D. Fox, Y. Lou, R. T. De Souza, M. J. Huang, W. C. Hsi, C. Schwarz, C. Williams, D. R. Bowman, J. Dinius, C. K. Gelbke, T. Glasmacher, D. O. Handzy, M. A. Lisa, W. G. Lynch, Graham F. Peaslee, L. Phair, M. B. Tsang, G. Vanburen, R. J. Charity, L. G. Sobotka, W. A. Friedman Aug 1995

Assessing The Evolutionary Nature Of Multifragment Decay, E. Cornell, T. M. Hamilton, D. Fox, Y. Lou, R. T. De Souza, M. J. Huang, W. C. Hsi, C. Schwarz, C. Williams, D. R. Bowman, J. Dinius, C. K. Gelbke, T. Glasmacher, D. O. Handzy, M. A. Lisa, W. G. Lynch, Graham F. Peaslee, L. Phair, M. B. Tsang, G. Vanburen, R. J. Charity, L. G. Sobotka, W. A. Friedman

Faculty Publications

Multifragment decays of central collisions in 84Kr+197Au at E/A=35, 55, and 70 MeV are studied. The dependence of the extracted emission time on the velocity of the fragment pair is investigated. More energetic pairs manifest a stronger Coulomb interaction, indicating emission from a source of smaller spatial-temporal extent than less energetic pairs. This trend can be understood in the context of a statistical model that allows the source characteristics to evolve as the fragments are emitted.

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Ultrastructural Immunolocalization Of Histones (H2b, H3, H4), Transition Protein (Tp1) And Protamine In Rabbit Spermatids And Spermatozoa Nuclei. Relation To Condensation Of The Chromatin, J L. Courtens, Wilson Stephen Kistler, L Plöen Aug 1995

Ultrastructural Immunolocalization Of Histones (H2b, H3, H4), Transition Protein (Tp1) And Protamine In Rabbit Spermatids And Spermatozoa Nuclei. Relation To Condensation Of The Chromatin, J L. Courtens, Wilson Stephen Kistler, L Plöen

Faculty Publications

The histones H2B, H3 and H4, the transition protein TP1 and protamine were localised using ultrastructural immunocytochemistry in nuclei of rabbit spermatids and spermatozoa. Histones are present in round spermatid nuclei and are lost during the elongation of nuclei. TP1 and protamine appear simultaneously in all nuclei during this period. TP1 is located at the periphery of chromatin cords, while protamine seems to be located at random in the same cords. TP1 is lost in most elongated sprematids during step 13 of spermiogenesis, and the protamine stays in all sperm nuclei. TP1 remains persent in some old spermatids and ejaculated …

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56. Sir Geoffrey Allan, Otto Vogl, Shigeko Suzuki Aug 1995

56. Sir Geoffrey Allan, Otto Vogl, Shigeko Suzuki

Otto Vogl

No abstract provided.

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Space-Time Characteristics Of Fragment Emission In The E/A=30 Mev 129xe + Natcu Reaction, D. R. Bowman, N. Colonna, W. A. Friedman, L. Celano, M. D'Agostino, J. D. Dinius, A. Ferrero, C. K. Gelbke, T. Glasmacher, D. O. Handzy, D. Horn, W. C. Hsi, M. Huang, I. Iori, M. A. Lisa, W. G. Lynch, G. V. Margagliotti, P. M. Milazzo, C. P. Montoya, A. Moroni, Graham F. Peaslee, L. Phair, F. Petruzzelli, R. Scardaoni, C. Schwarz, M. B. Tsang, C. Williams Aug 1995

Space-Time Characteristics Of Fragment Emission In The E/A=30 Mev 129xe + Natcu Reaction, D. R. Bowman, N. Colonna, W. A. Friedman, L. Celano, M. D'Agostino, J. D. Dinius, A. Ferrero, C. K. Gelbke, T. Glasmacher, D. O. Handzy, D. Horn, W. C. Hsi, M. Huang, I. Iori, M. A. Lisa, W. G. Lynch, G. V. Margagliotti, P. M. Milazzo, C. P. Montoya, A. Moroni, Graham F. Peaslee, L. Phair, F. Petruzzelli, R. Scardaoni, C. Schwarz, M. B. Tsang, C. Williams

Faculty Publications

Intermediate-mass-fragment emission has been studied in central E/A=30 MeV Xe129+natCu reactions. The measured fragment multiplicities, reduced-velocity correlation functions, and emission velocities have been compared with schematic three-body trajectory calculations and with three statistical models with input based upon a dynamical BNV code. The statistical models which include expansion either explicitly or implicitly are able to generate a sufficient number of fragments. The three-body trajectory calculations indicate a mean emission time of ≊200 fm/c, consistent with sequential decay. Dynamical expanding-emitting source calculations predict a similar time scale for fragment emission and give satisfactory agreement with the experimental correlation functions if the …

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37th Rocky Mountain Conference On Analytical Chemistry Jul 1995

37th Rocky Mountain Conference On Analytical Chemistry

Rocky Mountain Conference on Magnetic Resonance

Final program, abstracts, and information about the 37th annual meeting of the Rocky Mountain Conference on Analytical Chemistry, co-sponsored by the Colorado Section of the American Chemical Society and the Rocky Mountain Section of the Society for Applied Spectroscopy. Held in Denver, Colorado, July 23-27, 1995.

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Reducibility And Thermal Scaling Of Charge Distributions In Multifragmentation, L. Phair, K. Tso, R. Ghetti, G. J. Wozniak, L. G. Moretto, R. T. De Souza, D. R. Bowman, N. Carlin, C. K. Gelbke, W. G. Gong, Y. D. Kim, M. A. Lisa, W. G. Lynch, Graham F. Peaslee, M. B. Tsang, F. Zhu Jul 1995

Reducibility And Thermal Scaling Of Charge Distributions In Multifragmentation, L. Phair, K. Tso, R. Ghetti, G. J. Wozniak, L. G. Moretto, R. T. De Souza, D. R. Bowman, N. Carlin, C. K. Gelbke, W. G. Gong, Y. D. Kim, M. A. Lisa, W. G. Lynch, Graham F. Peaslee, M. B. Tsang, F. Zhu

Faculty Publications

A strong thermal signature is found in the charge distributions associated with multifragmentation from the reaction 36Ar+197Au at E/A=110 MeV. The n-fold charge distributions are reducible to the onefold charge distributions through a simple scaling that is dictated by fold number and charge conservation.

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Synthesis And Characterization Of Novel Fluorine Containing Alkylsulfonyls And Sulfonates : Fluorinated Sulfonyl Methanes And Derivatives, Nelson R. Holcomb Jul 1995

Synthesis And Characterization Of Novel Fluorine Containing Alkylsulfonyls And Sulfonates : Fluorinated Sulfonyl Methanes And Derivatives, Nelson R. Holcomb

Dissertations and Theses

A series of salts of the strong fluorocarbon acid bis(trifluoromethylsulfonyl)methane were made: (CF3S02 ) 2CHK, (CF3S02 ) 2CHLi, [ (CF3S02 ) 2CH] 2Ca, [ (CF3S02 ) 2CH] 2Hg, (CF3S02 ) 2CHAg, [ (CF3S02 ) 2CH] 3La. Their reactivity and use as organic intermediates were investigated. The salts were made from their corresponding carbonates, oxides, or hydrides. The reaction times for the salts is generally short, however the purification process was laborious, involving recrystallization from organic solvents and drying under vacuum. The lithium salt is being evaluated as a solid state battery electrolyte. Derivatives of bis(trifluoromethylsulfonyl)methane were made by using the …

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57. Peter Plesch, Otto Vogl, Traudl Plesch Jul 1995

57. Peter Plesch, Otto Vogl, Traudl Plesch

Otto Vogl

No abstract provided.

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Angle-Resolved Photoelectron Spectroscopy Of C60, T. Liebsch, O. Plotzke, Franz Heiser, U. Hergenhahn, Oliver Hemmers, R. Wehlitz, J. Viefhaus, B. Langer, S. B. Whitfield, U. Becker Jul 1995

Angle-Resolved Photoelectron Spectroscopy Of C60, T. Liebsch, O. Plotzke, Franz Heiser, U. Hergenhahn, Oliver Hemmers, R. Wehlitz, J. Viefhaus, B. Langer, S. B. Whitfield, U. Becker

Environmental Studies Faculty Publications

Angle-resolved photoelectron spectra of gaseous C60 were recorded in the photon energy regions from 21 to 108 eV and from 295 to 320 eV. Partial cross sections σ and the angular distribution anisotropy parameter β vary significantly with photon energy, particularly in the near-threshold region of the valence and the core ionization regimes. Some of these effects may be attributed to scattering of the outgoing photoelectron by the atoms of the ionized C60 molecule. Our results indicate that the observed satellites of the C(1s) main line are most likely of shake-up character. Low-energy electrons emitted below the shake-off …

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Environments Of The Four Tryptophans In The Extracellular Domain Of Human Tissue Factor: Comparison Of Results From Absorption And Fluorescence Difference Spectra Of Tryptophan Replacement Mutants With The Crystal Structure Of The Wild-Type Protein, C. A. Hasselbacher, E. Rusinova, R. Rusinova, R. A. Kohanski, W. Lam, A. Guha, J. Du, T. C. Lin, I. Polikarpov, C. W. G. Boys, Y. Nemerson, W. H. Konigsberg, J. B. A. Ross Jul 1995

Environments Of The Four Tryptophans In The Extracellular Domain Of Human Tissue Factor: Comparison Of Results From Absorption And Fluorescence Difference Spectra Of Tryptophan Replacement Mutants With The Crystal Structure Of The Wild-Type Protein, C. A. Hasselbacher, E. Rusinova, R. Rusinova, R. A. Kohanski, W. Lam, A. Guha, J. Du, T. C. Lin, I. Polikarpov, C. W. G. Boys, Y. Nemerson, W. H. Konigsberg, J. B. A. Ross

Chemistry and Biochemistry Faculty Publications

The local environments of the four tryptophan residues of the extracellular domain of human tissue factor (sTF) were assessed from difference absorption and fluorescence spectra. The difference spectra were derived by subtracting spectra from single Trp-to-Phe or Trp-to-Tyr replacement mutants from the corresponding spectrum of the wild-type protein. Each of the mutants was capable of enhancing the proteolytic activity of factor Vila showing that the mutations did not introduce major structural changes, although the mutants were more susceptible to denaturation by guanidinium chloride. The difference spectra indicate that the Trp residues are buried to different extents within the protein matrix. …

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Effect Of Micelles And Mixed Micelles On Efficiency And Selectivity Of Antibiotic-Based Capillary Electrophoretic Enantioseparations, Kimber L. Rundlett, Daniel W. Armstrong Jul 1995

Effect Of Micelles And Mixed Micelles On Efficiency And Selectivity Of Antibiotic-Based Capillary Electrophoretic Enantioseparations, Kimber L. Rundlett, Daniel W. Armstrong

Chemistry Faculty Research & Creative Works

Vancomycin (an oligophenolic, glycopeptide, macrocyclic antibiotic) has been shown to be a superb chiral selector for anionic and neutral compounds. It was found that adding sodium dodecyl sulfate to the run buffer increased efficiency by over 1 order of magnitude, decreased analysis times, and reversed the elution order of the enantiomers. This allows for control of the retention order as well as the resolution of enantiomers in complex mixtures in a single run. A mechanism is proposed which explains all of the observed effects and is verified experimentally. Since vancomycin is present in both the micelle and in free solution, …

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Relative Stabilities Of Dna 3-Way, 4-Way And 5-Way Junctions (Multi-Helix Junction Loops) - Unpaired Nucleotides Can Be Stabilizing Or Destabilizing, Neocles B. Leontis, Julie L. Kardmas, Amy J. Ravin Jun 1995

Relative Stabilities Of Dna 3-Way, 4-Way And 5-Way Junctions (Multi-Helix Junction Loops) - Unpaired Nucleotides Can Be Stabilizing Or Destabilizing, Neocles B. Leontis, Julie L. Kardmas, Amy J. Ravin

Chemistry Faculty Publications

Competition binding and UV melting studies of a DNA model system consisting of three, four or five mutually complementary oligonucleotides demonstrate that unpaired bases at the branch point stabilize three- and five-way junction loops but destabilize four-way junctions. The inclusion of unpaired nucleotides permits the assembly of five-way DNA junction complexes (5WJ) having as few as seven basepairs per arm from five mutually complementary oligonucleotides. Previous work showed that 5WJ, having eight basepairs per arm but lacking unpaired bases, could not be assembled I[Wang,Y.L., Mueller,J.E., Kemper,B. and Seeman,N.C. (1991) Biochemistry, 30, 5667-5674]. Competition binding experiments demonstrate that four-way junctions (4WJ) …

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Acid-Base Chemical Mechanism Of Aspartase From Hafnia Alvei, Moon Young Yoon, Kim A. Thayer-Cook, Anthony J. Berdis, William E. Karsten, Klaus D. Schnackerz, Paul F. Cook Jun 1995

Acid-Base Chemical Mechanism Of Aspartase From Hafnia Alvei, Moon Young Yoon, Kim A. Thayer-Cook, Anthony J. Berdis, William E. Karsten, Klaus D. Schnackerz, Paul F. Cook

Chemistry Faculty Publications

An acid-base chemical mechanism is proposed for Hafnia alvei aspartase in which a proton is abstracted from C-3 of the monoanionic form of L-aspartate by an enzyme general base with a pK of 6.3-6.6 in the absence and presence of Mg2+. The resulting carbanion is presumably stabilized by delocalization of electrons into the β-carboxyl with the assistance of a protonated enzyme group in the vicinity of the β-carboxyl. Ammonia is then expelled with the assistance of a general acid group that traps an initially expelled NH3 as the final NH+4 product. In agreement with the function of the general acid …

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Synthesis And Characterization Of A Porphyrin Dyad, Dale A. Braden Jun 1995

Synthesis And Characterization Of A Porphyrin Dyad, Dale A. Braden

Dissertations and Theses

The sun is a bountiful source of energy for our planet. .With the advent of photovoltaic cells, man has begun harnessing the sun's radiant energy, turning it into a form more directly useful: electricity. Commercially available solar cells currently operate at about 13% efficiency, sufficiently high to make them a viable source of electrical energy. It is of great interest, however, to improve their conversion efficiency, and to lower the cost of production so as to make them more economical, and thereby reduce our dependence upon traditional "dirty" sources of energy such as coal and oil. It has been found …

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58. Koichi Hatada, Otto Vogl, Michiko Hatada Jun 1995

58. Koichi Hatada, Otto Vogl, Michiko Hatada

Otto Vogl

No abstract provided.

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Vibrational-State-Dependent Decay Of The Co C(1s) Excitation, N. Saito, Franz Heiser, Oliver Hemmers, A. Hempelmann, K. Wieliczek, J. Viefhaus, U. Becker Jun 1995

Vibrational-State-Dependent Decay Of The Co C(1s) Excitation, N. Saito, Franz Heiser, Oliver Hemmers, A. Hempelmann, K. Wieliczek, J. Viefhaus, U. Becker

Environmental Studies Faculty Publications

Molecular ionization and ionic fragmentation of core excited CO valence and Rydberg states are studied by partial-ion-yield spectroscopy at vibrational resolution. The vibrational intensities of the Rydberg excitations differ significantly depending on the ionization and/or fragmentation channel. The observed intensity variations are explained by nondissociative excited final ionic states of the subsequent molecular Auger decay. The vibrational levels of these final states become selectively depopulated due to interaction with dissociative decay channels leading to ionic fragmentation.

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Space-Time Ambiguity Of Two- And Three-Fragment Reduced Velocity Correlation Functions, T. Glasmacher, L. Phair, D. R. Bowman, C. K. Gelbke, W. G. Gong, Y. D. Kim, M. A. Lisa, W. G. Lynch, Graham F. Peaslee, R. T. De Souza, M. B. Tsang, F. Zhu Jun 1995

Space-Time Ambiguity Of Two- And Three-Fragment Reduced Velocity Correlation Functions, T. Glasmacher, L. Phair, D. R. Bowman, C. K. Gelbke, W. G. Gong, Y. D. Kim, M. A. Lisa, W. G. Lynch, Graham F. Peaslee, R. T. De Souza, M. B. Tsang, F. Zhu

Faculty Publications

Reduced-velocity correlation functions between two and three intermediate mass fragments are compared for central Ar36+197Ar collisions at E/A=50 MeV. Previously published N-body Coulomb-trajectory calculations, capable of reproducing the measured two-fragment reduced velocity-correlation function, describe the measured three-fragment correlation function equally well. Moreover, ambiguities between source size and lifetime observed in the analysis of two-fragment correlations remain unresolved in the three-fragment correlation function.

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Fluorescence Studies Of Cyclodextrin Polymers: A Study Of The Binding Of Various Fluorescence Probes To Cyclodextrin Polymers, Karen Ann Colwell Jun 1995

Fluorescence Studies Of Cyclodextrin Polymers: A Study Of The Binding Of Various Fluorescence Probes To Cyclodextrin Polymers, Karen Ann Colwell

Honors Theses

Cyclodextrins (CDs) are cyclical oligosaccarides which exist as 6, 7, or 8 glucopyranose units joined by α-1,4 linkages, referred to as α, β, and γ CDs, respectively. Their structure resembles that of a truncated cone in which the interior cavity is hydrophobic while the exterior remains hydrophilic. This allows CDs to form inclusion complexes with nonpolar molecules in an aqueous environment. Polymerization of CDs (CDPs) has been carried out using epichlorohydrin which connects the CD cavities by an average of 12-15 repeating glyceryl linker units. The binding of various fluorescence probes to CD monomers has been studied. In particular, pyrene …

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Influence Of Salt Bridge Formation On Helix Stability, Angelo Carmine Nicoletta Jun 1995

Influence Of Salt Bridge Formation On Helix Stability, Angelo Carmine Nicoletta

Honors Theses

One of the most common structural elements in proteins is the a-helix. The main goal of this study was to see If the helical properties of short peptide chains could be increased by the formation of salt bridges between side chains. It has been shown that i,i+4 peptides posses helic; I characier. The research that has been done was to make a hybrid peptide chain, that had partial i,i+4 and partial i,i+3 salt bridge formation. The hybrid peptide was a i+4, i+3, i+4 peptide chain. The overall purpose of making this type of hybrid peptide was to make the approximate …

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Applications Of A Diode-Laser-Based Detector To On-Line Determinations Involving Methylene Blue, Michelle Ann Spaziani Jun 1995

Applications Of A Diode-Laser-Based Detector To On-Line Determinations Involving Methylene Blue, Michelle Ann Spaziani

Honors Theses

The application of an inexpensive diode-laser-based detector for flow injection analysis (FIA), and the on-line determination of sulfide using the "Methylene Blue (MB) Method" is presented. The detector is designed for simultaneous measurements of transmittance and fluorescence. A 670-nm diode laser is the excitation source; photodiodes serve as detector elements. The flow cell is constructed of a piece of square-cross-section quartz capillary tubing. The MB Method employs N, N-dimethyl-p-phenylenediamine (DMPD), iron III, and sodium sulfide reacting to form MB; a triple-line flow-injection manifold is used. Performed previously using conventional UV-Vis instrumentation, optimized conditions included one reagent dissolved in 9 M …

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Studies Toward A Chiral, Charge Separated, Water Soluble Cyclophane, Danuta Trzebinska-Yager Jun 1995

Studies Toward A Chiral, Charge Separated, Water Soluble Cyclophane, Danuta Trzebinska-Yager

Honors Theses

It has been suggested that the key issue in the structure-function correlation in enzyme catalysis is electrostatic stabilization of the ionic transition states. In order to mimic receptors in biological systems we designed a novel hydrophilic macrocycle, 10, with an electrostatic dipole across its hydrophobic cavity. The dipole moment would be established between a positively charged Fe(II)-terpyridyl complex on one end of the macrocycle and the two carboxylate substituents at the opposite end of the receptor. An experimental strategy based on a convergent synthesis is presented.

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Studies On Low Temperature Performance Of Rechargeable Mh-Ni Batteries, Wenkuan Zhang, Jingxian Shi, Yu Wan Lou, Qiusheng Duan May 1995

Studies On Low Temperature Performance Of Rechargeable Mh-Ni Batteries, Wenkuan Zhang, Jingxian Shi, Yu Wan Lou, Qiusheng Duan

Journal of Electrochemistry

The Dependence of low temperature performance on the alloy composition andelectrolyte component for rechargeable MH-Ni batteries is studied, the suitable composition of alloyand electrofyte are founds.

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