Harbin Engineering University

About: Harbin Engineering University is a education organization based out in Harbin, Heilongjiang, China. It is known for research contribution in the topics: Control theory & Computer science. The organization has 31149 authors who have published 27940 publications receiving 276787 citations. The organization is also known as: HEU.

One-Step Synthesis and Gas-Sensing Characteristics of Uniformly Loaded Pt@SnO2 Nanorods

Abstract: Highly sensitive gas sensors are realized from uniformly loaded Pt@SnO2 nanorods, which are synthesized via one-step hydrothermal routes. At 300 °C, the sensitivity of the sensors upon exposure to 200 ppm ethanol is up to 39.5. Such a high gas sensing can be attributed to both the chemical and the electrical contribution of Pt. Interestingly, at 200 °C, the response of the sensors is characterized by opposite variations of resistances, which probably arise from temperature-dependent forms of surface oxygen ions. The present results demonstrate an available direction for realizing high-performance gas sensors.

Ice breaking by a collapsing bubble

Abstract: This work focuses on using the power of a collapsing bubble in ice breaking. We experimentally validated the possibility and investigated the mechanism of ice breaking with a single collapsing bubble, where the bubble was generated by underwater electric discharge and collapsed at various distances under ice plates with different thicknesses. Characteristics of the ice fracturing, bubble jets and shock waves emitted during the collapse of the bubble were captured. The pattern of the ice fracturing is related to the ice thickness and the bubble–ice distance. Fractures develop from the top of the ice plate, i.e. the ice–air interface, and this is attributed to the tension caused by the reflection of the shock waves at the interface. Such fracturing is lessened when the thickness of the ice plate or the bubble–ice distance increases. Fractures may also form from the bottom of the ice plate upon the shock wave incidence when the bubble–ice distance is sufficiently small. The ice plate motion and its effect on the bubble behaviour were analysed. The ice plate motion results in higher jet speed and greater elongation of the bubble shape along the vertical direction. It also causes the bubble initiated close to the ice plate to split and emit multiple shock waves at the end of the collapse. The findings suggest that collapsing bubbles can be used as a brand new way of ice breaking.