A nanostructured germanium surface was prepared by irradiating single-crystalline Ge with femtosecond laser pulses under an ambient condition. The processed samples were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction, and Raman spectroscopy. The results have demonstrated that the processed area contains small, nanosized particles attached to microstructures. Photoluminescence in the visible region as well as asymmetric broadening of the Raman spectral feature and its downward peak shift were observed from the processed Ge surface. Our approach can be applied to pattern photoluminescent Ge nanostructures with a spatial resolution of what?

>> In order to achieve simultaneously the ultra-low NOx, the high power and the high efficiency in a hydrogen-fueled engine with SI and the external mixture, the effects of low temperature combustion, performance and exhaust are compared and analyzed by the application of the lean boosting. As the results, the decrease rate of the high temperature in the hydrogen is less decreased than the other fuels by high constant-volume specific heat. However, when the conditions of 1.7bar and Φ=0.33 are reached by the lean boosting, the maximum gas temperature of hydrogen is decreased under the temperature of NOx formation and it is possible to stabilize combustion below 2% of COVimep. Also, at that condition, it is feasible to achieve simultaneously NOx-free and the power of gasoline level. Therefore, it is found that the lean boosting is useful in the hydrogen-fueled engine.