Search

Your search keyword '"Wang, Shumei"' showing total 1,314 results
Start Over Author "Wang, Shumei"
1,314 results on '"Wang, Shumei"'

10. Rapid ascent trajectory optimization of rocket-based combined cycle hypersonic vehicle

Author

YAN Xunliang, WANG Shumei, WANG Peichen, and LIU Haili

Subjects
rocket-based combined cycle, hypersonic vehicle, ascent trajectory optimization, sequential convex optimization, second-order lag of control system, Motor vehicles. Aeronautics. Astronautics, TL1-4050
Abstract

The ascent trajectory design of a rocket-based combined cycle (RBCC) hypersonic vehicle has many typical characteristics, including the complex working mode of the RBCC power system, strong coupling between thrust and flight state, strong nonlinear model and many complex constraints etc. This paper proposes a rapid trajectory optimization method based on sequential convex optimization to optimize the complex ascent trajectory with the RBCC power system. Firstly, a mathematical model for optimizing the ascent trajectory of the RBCC hypersonic vehicle is established to describe the angle of attack control system with and without the second-order lag. Then, the optimization model is made convex and discretized based on the convex optimization theory, and a trajectory optimization strategy is improved. Finally, taking the maximum terminal mechanical energy as optimization objective, the ascent trajectory optimization is simulated in cases with and without the second-order lag in the angle of attack control system. The simulation results show that the proposed mathematical model and the ascent trajectory optimization method are rapid and reliable and that the optimization results meet the characteristics of the RBCC power system and provide reference for the application of a RBCC power system and the design of an angle of attack control system.

Published
2023
Full Text
View/download PDF

21. Fair Re-Ranking Recommendation Based on Debiased Multi-graph Representations

Author

Han, Fangyu, Wang, Shumei, Zhao, Jiayu, Wu, Renhui, Rui, Xiaobin, Wang, Zhixiao, Goos, Gerhard, Founding Editor, Hartmanis, Juris, Founding Editor, Bertino, Elisa, Editorial Board Member, Gao, Wen, Editorial Board Member, Steffen, Bernhard, Editorial Board Member, Yung, Moti, Editorial Board Member, Yang, Xiaochun, editor, Suhartanto, Heru, editor, Wang, Guoren, editor, Wang, Bin, editor, Jiang, Jing, editor, Li, Bing, editor, Zhu, Huaijie, editor, and Cui, Ningning, editor

Published
2023
Full Text
View/download PDF

37. Secretion and delivery of virulence proteins from Phytophthora infestans to its host

Author

Wang, Shumei and Birch, Paul

Subjects
580
Abstract

Potato blight, a ravaging disease caused by the oomycete Phytophthora infestans, is a major threat to global food security. P. infestans secretes effector proteins that are delivered inside (cytoplasmic effector) or outside (apoplastic effector) plant cells to neutralise host immunity. One of the most well characterised classes of cytoplasmic effectors are the RXLR (Arg-any amino acid-Leu-Arg) class. RXLR is a highly conserved motif in genes encoding secreted proteins across many oomycete genomes, and is required for effector translocation from pathogen into host cells. However, little is known about how and where effectors are delivered during infection and the role of the RXLR motif in the translocation process. In the first part of this study, a set of RXLR cytoplasmic effectors were characterised in terms of host subcellular localisation and their effect on pathogen colonisation. Subsequently, two host nuclear-localised cytoplasmic effectors, Pi04314 and Pi22926, were selected and mutants created in which the RXLR motif was disabled. The wild-type and mutant forms were expressed in P. infestans. Both RXLR wildtype and RXAA mutant effector fusions were secreted from haustoria, finger-like structures that form intimate interactions with host cells. Importantly, only wildtype effectors accumulated inside the host cell nuclei, their site of activity. Strikingly, my data demonstrate that the RXLR motif determines an alternative secretion pathway from P. infestans, with secretion of RXAA-mRFP mutant effector fusions, like apoplastic effectors, cell wall degrading enzymes and PAMP-like proteins, was inhibited in vitro and in planta by Brefeldin A (BFA), which is a conventional ER-to-Golgi-mediated secretion inhibitor. Wildtype cytoplasmic effectors follow an (BFA) insensitive secretion route for delivery into plant cells. I hypothesised that extracellular vesicles (EVs) may be the mechanism of RXLR effector translocation from pathogen into host cells. EVs are secreted by diverse organisms to facilitate intercellular and extracellular communication, promote infection and evade host immune responses. I used ultracentrifugation, followed by transmission electron microscopy to identify EVs from P. infestans culture in vitro. Immunoblotting showed that secreted EVs mediate secretion of RXLR effectors but not apoplastic effectors. This work is a major breakthrough in the understanding of plant-pathogen interactions, providing more details about the protein weapons of P. infestans, and could be exploited to develop chemicals to disrupt the specific secretory processes and inhibit pathogen infection.

Published
2019

Catalog

Books, media, physical & digital resources
See catalog results