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The electron-transfer kinetics for each of three copper(Il/I) tripodal ligand complexes reacting with multiple reducing and oxidizing counter reagents have been examined in aqueous solution at 25 °C, µ = 0.10 M. For all of the ligands studied, an amine nitrogen serves as the bridgehead atom. Two of the ligands (PMMEA and PEMEA) contain two thioether sulfurs and one pyridyl nitrogen as donor atoms on the appended legs while the third ligand (BPEMEA) has two pyridyl nitrogens and one thioether sulfur. Very limited kinetic studies were also conducted on two additional closely related tripodal ligand complexes. The results are compared to our previous kinetic study on a Cu(ll/I) system involving a tripodal ligand (TMMEA) with thioether sulfur donor atoms on all three legs. In all systems, the Cu(ll/I) electron self-exchange rate constants (k[sub 11]) are surprisingly small, ranging approximately 0.0350 M[sup -1] s[sup -1]. The results are consistent with earlier studies reported by Yandell involving the reduction of Cu(ll) complexes with four similar tripodal ligand systems, and it is concluded that the dominant reaction pathway involves a metastable Cu[sup II]L intermediate species (designated as pathway B). Since crystal structures suggest that the ligand reorganization accompanying electron transfer is relatively small compared to our earlier studies on macrocyclic ligand complexes of Cu(ll/I), it is unclear why the k[sup 11] values for the tripodal ligand systems are of such small magnitude. [ABSTRACT FROM AUTHOR]

Examines the electron-transfer kinetics for five closely related copper (Cu)(II/I) complexes formed with possible diastereomers. Crystal structures of the Cu(II) complexes; Details of the Cu(II/I) cross- reaction kinetics; Efficacy of entatic state concept on Cu(II/I) systems.

Investigates the kinetics of copper(II) reacting with cyclohexanediyl derivatives of cyclic tetrathiaether. Macrocylic ligand constraints; Metal-ion exchange; Proposed stepwise mechanism; Intermediate interconversions; Consideration of intermediate buildup for the polythiaethers; Assignment of rate-determining step.

A thermal stress range analysis of tungsten-rhenium thin film thermocouples based on ceramic substrates is presented to analyze the falling off and breakage problems caused by the mismatch of the thermal stresses in thin film thermocouples (TFTCs) and substrate, and nano-indentation experiments are done to measure and calculate the film stress to compare with the simulation results. Optimal design and fabrication of tungsten-rhenium TFTCs based on ceramic substrates is reported. Static high temperature tests are carried out, which show the optimization design can effectively reduce the damage caused by the thermal stress mismatch. [ABSTRACT FROM AUTHOR]

To explore the performance of the ground source thermal energy management system under the cold and heat sources, based on the cold and heat auxiliary technology, a ground source thermal energy composite management system is constructed and simulated. The constructed ground source heat pump-refrigeration unit-hybrid heating management system of urban heating networks, as well as the simple system, are analyzed and investigated in terms of power consumption and underground temperature control. The research results show that the constructed ground source heat pump-refrigeration unit-hybrid heating management system of the urban heating network has lower power and energy consumption than a simple system during the same period, which meets the economic requirements and guarantees the system with relatively low energy consumption. For underground temperature control, the constructed system is more stable than a simple system without excessive temperature fluctuations. The operation control strategy of the constructed system is mainly for chiller units, heat pump units, cooling towers, source side, and side circulation water pump modules. In summary, the constructed ground source heat pump-refrigeration unit-hybrid heating management system of an urban heating network based on the ground source heat pump meets the requirements for energy consumption and temperature control and can operate the control strategy normally. The results are significant for subsequent researches on the ground source thermal energy management system based on cold and heat auxiliary technology. [ABSTRACT FROM AUTHOR]

A tungsten-rhenium thin film thermocouple is designed and fabricated, depending on the principle of thermal-electric effect caused by the high temperature. The characteristics of thin film thermocouples in different temperatures are investigated via numerical analysis and analog simulation. The working mechanism and thermo-electric features of the thermocouples are analyzed depending on the simulation results. Then the thin film thermocouples are fabricated and calibrated. The calibration results show that the thin film thermocouples based on the tungsten-rhenium material achieve ideal static characteristics and work well in the practical applications. [ABSTRACT FROM AUTHOR]