A Study on Photoacoustic Phase Spectra of Rare Earth Complexes with Oxine

Photoacoustic phase is the time delay that occurs from light to acoustic signal. the phase includes two components: one is the time delay that occurs during the process in which light absorbed by a sample converts into heat; the other is the time delay caused from heat to acoustic signal. a modified formula of PA phase is presented based on the R-G theory considering the phase caused by non-radiative relaxation processes. the phase is associated with absorption coefficient (β), thermal diffusion length of sample (μ_s), the longest lifetime of all excited states (r), and the ratio of rapid to slow heat component (R). When the photoacoustic signal is saturated the phase is associated with only T and R. the effect of different rare earth ions on the PA phase spectra of the ligand (oxine) in the rare earth complexes are reported and are well explained by using the phase formula of PA saturation.     

Comparison of the Kinetics of the Exchange Mechanism of the Thallium Ion with 18C6 and with Pentaglyme in Acetonitrile Solutions

Abstract

In acetonitrile solutions, the exchange reaction is bimolecular in the Tl⁺ + 18C6 system, while in the Tl⁺ + pentaglyme system the associative-dissociative and the bimolecular mechanisms coexist at room temperature and the bimolecular exchange reaction dominates at 263° K. For the bimolecular mechanism in the case of Tl⁺ + 18C6 and the associative-dissociative mechanism in the case of Tl⁺ + pentaglyme, the activation energies of the exchange reactions change with temperature. At 298° K, in the Tl⁺ + 18C6 system the activation energy for the bimolecular exchange reaction is ≈ 2 kcal.mol^?1 and exchange rate constant (k₁) is (4.1 ± 0.1) × 10⁷ s^?1mol^?1; in the Tl⁺ + pentaglyme system, the activation energy for the associative-dissociative exchange reaction is ≈ 5 kcal mol^?1 and the decomplexation rate constant (k_?2) is (2.2 ± 0.4) X 10⁵ s^?1. The activation energy for the bimolecular exchange in the Tl⁺ + pentaglyme system was determined to be 3.00 ± 0.05 kcal.mol_?1 and the exchange rate constant (3.0 ± 0.1) X 10⁸ s^?1 mol^?1.     

Application of HPLC-Thermospray Flame AAS: Interaction Between Heavy Metals and Duckweed Chlorophyll

Thermospray nebulizer interfaced HPLC-Flame AAS was used to study the effect of heavy metals (Al, Cd, Cu, Hg and Zn) on the chlorophylls of duckweed. Flame AAS was used as a metal specific detector of HPLC. Study indicated that heavy metals promote the degradation of chlorophylls. No evidence of direct replacement of central magnesium with heavy metals was found.     

The Synthesis,Vibrational Spectra,Electronic Spectra,and Thermal Analysis of Some Mixed Complexes with Planar Dithiooxamides

Planar Pd(LH)₂ complexes (LH₂ = H₂N C S C S N H₂, CH₃HNCSCSNHCH₃) form mixed polymeric complexes with Ni(II), Cu(II), Zn(II) and Cd(II) in alcalic media, where the planar Pd(LH)₂ complexes act as tetradentates with N-coordination. The electronic spectra and thermal behaviour are discussed, a thorough investigation of the i.r. spectra is presented and special attention has been given to the H/D, CH₃/CD₃ and ⁵⁸Ni/⁶²Ni, ⁶³Cu/⁶⁵Cu and ⁶⁴Zn/⁶⁸Zn isotopic shifts.     

Spectra Studies of Complexes Between Palladium (II), Nickel (II) and Amino Acids

The complexes of Ni (His) 2·H2O, Ni (Gly) 2·2H2O, Pd (His)Cl2·H2O and Pd(Gly) 2·2H2O were synthesized. And the IR, electronic absorption and photoacoustic spectra of these complexes were measured in solid state. The nature of the metal-carboxylate coordinate bond were deduced from the variation in the carboxyl stretching frequencies. And the d-d transition absorptions of these complexes were interpreted quantitatively with the 3d scaling radial theory. Therefore, the structural characterizations were also discussed with their spectral behaviors.     

High pressure stability of protein complexes studied by static and dynamic light scattering

The high pressure dissociation of hemocyanin prepared from the lobster Homarus americanus and casein micelles from cow milk were observed by in situ light scattering. The hemocyanin dodecamer dissociated via a hexamer into monomers in a two-step three-species reaction. The influence of ligands and the effector l-lactate on the dissociation behavior was investigated. While no effect by carbon monoxide after exchanging the ligand oxygen was observed, the addition of the effector l-lactate led to a decrease in the pressure stability. Due to a trimer intermediate which was found to be stabilized by l-lactate, the dissociation reaction in the presence of the effector was analyzed by a three-step four-species reaction. In the case of casein micelles, a two-step dissociation mechanism was found. The stabilizing interactions of casein micelles were identified and separated.     

Tracer Study on Catalytic Hydrogen Exchange Reactions over Nickel Catalyst

In heterogeneous catalysis it is important to know the reactivity of C-H bond in the hydrocarbon molecules. Experiments have been performed to obtain information about the exchange reaction of adsorbed hydrogen with methane and ethylene. In order to reduce the probability of forming products which contain more than one tritium atom, hydrogen labelled with H³ with low activity has been used.     

Teil II: Ergebnisse bei der Bestrahlung einzelner Nahrungsmittelgruppen (Zusammenfassender Bericht)

Nachdem im ersten Teil dieser Arbeit [170] einige Grundprobleme der Nahrungsmittelbestrahlung behandelt wurden, sollen nun die bei der Bestrahlung wichtiger Nahrungsmittelgruppen erzielten Ergebnisse dargelet und eine Einschätzung der Entwicklungstendenzen versucht werden.     

Aufbau und Erprobung von Flächenstrahlungsquellen als Sekimdärnormale zur Prüfung von Kontaminationsmeßgeraten für Betastrahler und zur Beglauhigung von Flächenstrahlungsquellen als Normale

Zur Prüfung von Kontaminationsmeβgeräten und zur Beglaubigung von Flächenstrahlungsquellen als Normale wurden im Deutscheti Amt für Meβwesen und Warenprüfung zwei Sälze von Flächenstrahlungsquellen mil den Betastrahlen ⁹⁰Sr/⁹⁰Y, ²⁰¹Tl und ⁶⁰Co angefertigt. Durch das dabei verwendete Herstellungsverfahren, bei dem je ein Tropfen rudioakliver Lösung in ein Feld eines vorgegebenen Rasters gebracht wurde, konnte eine sehr gleichmäβige Verteilung der akliven Substanz über die Quellenfläche erreicht und eine unmiltelbare Bestimmung der Flächenaktivitätswerte ermöglicht werden. Der besondere Aufbau der Flächenstrahlungsquellen geslatlet es, auf einfache Weise Meβfehler bei Kontaminationsme βgeräten, die durch das Material der Unterlage, auf dem sich die aktive Substanz befindet, und durch die Dicke der akliven Schicht hervorgerufen tcerden, zu erfassen oder zu eliminieren.     

Ion Exchange Separation of Eu3+ from Different Salt Solutions

Two samples of potassium zinc hexacyanoferrate were prepared using two different ratios of the initial materials. The distribution coefficient of Eu³⁺ on the two samples was determined. The effect of the cation concentration in the aqueous phase on the adsorption of Eu³⁺ was also studied. The mechanism of the exchange process was described on the light of the data obtained, and the equilibrium constant of the exchange reaction was also calculated.