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The electric resistivity, Seebeck coefficients and power factors of Y1-xEuxBaCo4O7+δ(x = 0.0, 0.05, 0.1, 0.2) ceramics were investigated from 400K to 1000K. The results show that the presence of Eu decreases electrical resistivity, and has little effect on Seebeck coefficients of the samples. The activation energy of conductivity is calculated by the Arrhenius plots in the semiconductive region. According to power factors, the optimum Eu substitution amount is x = 0.1, which results in a higher power factor of 67.5 μWm-1K-2at 1000K, 30% higher than unmodified sample YBaCo4O7+δ.

The experimental system was established in order to study the dynamic and economic performance of vehicle engine fuelled with LPG. Based on the experimental system, the variable experimental study including engine power, torque and consumption rate were carried out. The l results showed that with the rise of the engine rotational speed, power and torque of the engine fueled with LPG increased first and then decreased, but all of them were lower than that of the 93#gasoline. The consumption rate of the LPG was better than the 93#gasoline for the engine case at 2000r/min and 4000r/min on the energy consumption rate.

Co2-xCuxOy (x=0.0, 0.2, 0.4) Samples were prepared by solid-state reaction method and the effect of Cu substitution on the thermoelectric properties was investigated. The presence of Cu element improved the grain size and electrical conductivity, but Seebeck coefficients were reduced by Cu substitution. It was found Cu substitution is an effective way to improve the thermoelectric performance system at high temperature.

The paper introduces the working principle of the sequential turbo-charging (STC) system of multi-turbocharger. To improve low-load performance and operating economy of the 234V12 diesel engine, a STC system of multi-turbocharger for the diesel engine was designed. Theoretical calculation and experimental research was done on this improved marine diesel engine. Then, a 3-phase STC system is presented by analyzing and comparing the test result and the switching boundary of this system is confirmed. The test results show that the low-load performance is improved obviously by use of multi-turbocharger STC system.