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.

Bubble dynamics and its applications

Abstract: Bubbles have very important applications in many fields such as shipbuilding engineering, ocean engineering, mechanical engineering, environmental engineering, chemical engineering, medical science and so on. In this paper, the research status and the development of the bubble dynamics in terms of theory, numerical simulation and experimental technique are reviewed, which cover the underwater explosion bubble, airgun bubble, spark bubble, laser bubble, rising bubble, propeller cavitation bubble, water entry/exit cavitation bubble and bubble dynamics in other fields. Former researchers have done a lot of researches on bubble dynamics and gained fruitful achievements. However, due to the complexity of the bubble motion, many tough mechanical problems remain to be solved. Based on the research progress of bubble dynamics, this paper gives the future research direction of bubble dynamics, aiming to provide references for researches related to bubble dynamics.

Hollow structured and flower-like C@MnCo2O4 composite for high electrochemical performance in a supercapacitor

Abstract: Binary metal oxide MnCo2O4 nanosheets wrapped on a hollow activated carbon shell (C@MnCo2O4) were successfully synthesized through a facile hydrothermal method followed by a calcination process. The novel structure of a flower-like C@MnCo2O4 composite, which consists in a good conductive carbon shell and well interconnected nanosheets, can efficiently facilitate electrolyte penetration and offers an expedite transport path for ions and electrons. Notably, the large surface of the hybrid composite (347 m2 g−1) can provide a large amount of active sites, which evidently accommodates the strain during cycling. Benefiting from this elegant combination and the effectively mesoporous structure, the specific capacitance of the C@MnCo2O4 composite can be achieved as high as 728.4 F g−1, which is, to the best of our knowledge, the highest value so far reported for MnCo2O4 based electrode materials. In addition, the C@MnCo2O4 composite exhibits enhanced rate capability and an excellent cycling stability of 95.9% retention after 1000 cycles at a high current density of 8 A g−1. Therefore, the desirable integrated electrical performance allows it to be a promising electrode material for supercapacitor applications.

Three-Dimensional Path Following of an Underactuated AUV Based on Fuzzy Backstepping Sliding Mode Control

Abstract: This paper addresses the problem of three-dimensional (3D) path following control for underactuated autonomous underwater vehicles in the presence of parameter uncertainties and external disturbances. Firstly, 3D path following error model was established based on virtual guidance method. Then, an adaptive robust control system was proposed using backstepping and sliding mode control, and we adopt fuzzy logic theory to approximate unknown nonlinear function to solve the problems of nonlinearity, uncertainties and external disturbances in the path following. System stability was proved by Lyapunov stable theory. Finally, simulations were conducted and the results showed that the controller is of excellent adaptability and robustness in the presence of parameter uncertainties and external disturbances.

Preparation of Nano- Li2FeSiO4 as Cathode Material for Lithium-Ion Batteries

Abstract: A sol―gel method based on citric acid was employed to prepare Li 2 FeSiO 4 as a cathode material for lithium-ion batteries. The citric acid acts as both a chelating agent and a carbon source in the synthetic process. The obtained Li 2 FeSiO 4 has a monoclinic unit cell in space group P2 1 . The average size of Li 2 FeSiO 4 particles is approximately 80 nm. The maximum discharge capacity of 153.6 mAh g ―1 is observed in the third cycle, and 98.3% of the maximum discharge capacity is retained after 80 charge― discharge cycles.