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Due to the failure of traditional oscillation mechanism based on an acoustic wave feedback loop and the supersonic spillage at the duct entrance, the unstart flow pattern of hypersonic inlets is quite different from that of traditional supersonic inlets. What's more, the hypersonic inlet unstart is more harmful, more closely coupled with the combustor, and has more demand for real-time control. Therefore, it should be drawn more attention in the development of hypersonic technology. In this paper, the main progress of the hypersonic inlet unstart is reviewed from its characteristics, classification, detection and control methods. The remaining problems are also analyzed and some issues for future study are suggested. [ABSTRACT FROM AUTHOR]

In order to operate efficiently in various operating conditions, a turbine-based combined cycle engine (TBCC) variable nozzle is proposed to adjust the area of the nozzle throat and the exit simultaneously. The performances of the nozzle at static condition and at different freestream Mach numbers are analyzed. Results show that the design has a preferable static performance and the thrust ratios are 0. 90, 0. 97 and 0. 98 in typical states. After the introduction of the external flow, the freestream can suppress the overexpansion of the exhaust flow effectively at the low Mach number condition (Ma = 0. 8), so the thrust coefficient is enhanced by 6.7%. In the high Mach number conditions (Ma = 2. 8,4. 0), though the flow pattern of the nozzle downstream is apparently affected by the external flow, the pressure distribution of the central body and the internal flow path is hardly affected. Therefore, there is no change in the thrust ratios which stay at 0. 97 and 0. 98, respectively. [ABSTRACT FROM AUTHOR]

Laccases are enzymes belonging to the group of multi-copper oxidases. These enzymes are widely distributed in insects, plants, fungi and bacteria. In general, laccases can oxidize an exceptionally high number of substrates, so they have broad applications in textile, pulp, food and the degradation of lignin. However, low yield, low activity and thermo-instability of laccase in nature limit the application of laccase. High efficient heterologous expression of the protein is an effective way for solving this problem. Here, we summarize the research advances of heterologous expression of eukaryote-origin laccases. We focus on the overexpression of eukaryote-origin laccases using different expression system and the method for improving the production yield and enzyme activity in yeast cells. Information provided in this review would be helpful for researchers in the field.