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Journal of Thermal Science 2020年第4期29卷 893-905页

作者： XU Wenfeng sun peng YANG Guogang HUANG Longsheng FU Wenguang Marine Engineering College Dalian Maritime UniversityDalian 116026China College of Airworthiness Civil Aviation University of ChinaTianjin 300300China

Inlet total pressure distortion has great adverse effects on the aero-engine performance. The distorted flow passes through the compressor and becomes non-uniform in the downstream blade rows. Different from previous studies based on the assumption of circumferential uniformity, this study aims to improve circumferential non-uniform flow with the non-axisymmetric structure. Non-axisymmetric stator clearance was adopted to resolve the effects of non-uniform flow caused by inlet total pressure distortion in this paper. The 9 stators with tip clearance were installed in the distorted region and the flow field structure and performance under different operating conditions was studied. The study finds that the non-axisymmetric compressor with 9 tip clearance stators can ensure compressor efficiency while improving compressor stability margin. What’s more, the separation range and strength in the distorted region can be reduced significantly and the anti-distortion capability of compressor can be enhanced.

关键词： total pressure distortion non-axisymmetric stator clearance transonic compressor numerical simulation

Adaptive mixture observation models for multiple object tracking

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Science in China(Series F) 2009年第2期52卷 226-235页

作者： CUI peng sun LiFeng YANG ShiQiang Department of Computer Science Tsinghua University Beijing 10084 China

Multiple object tracking （MOT） poses many difficulties to conventional well-studied single object tracking （SOT） algorithms, such as severe expansion of configuration space, high complexity of motion conditions, and visual ambiguities among nearby targets, among which the visual ambiguity problem is the central challenge. In this paper, we address this problem by embedding adaptive mixture observation models （AMOM） into a mixture tracker which is implemented in Particle Filter framework. In AMOM, the extracted multiple features for appearance description are combined according to their discriminative power between ambiguity prone objects, where the discriminability of features are evaluated by online entropy-based feature selection techniques. The induction of AMOM can help to surmount the incapability of conventional mixture tracker in handling object occlusions, and meanwhile retain its merits of flexibility and high efficiency. The final experiments show significant improvement in MOT scenarios compared with other methods.

关键词： motion tracking mixture tracker particle filter online feature selection

Age, Growth and Maturation of Largehead Hairtail (Trichiurus japonicus) in the East China Sea

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Journal of Ocean University of China 2022年第5期21卷 1244-1250页

作者： CHENG Shuo sun peng LIU Yang CHEN Qi SHI Zhengtong sun Runlong College of Fisheries Ocean University of ChinaQingdao 266003China College of Marine Life Sciences Ocean University of ChinaQingdao 266003China

Largehead hairtail(Trichiurus japonicus)is a commercially important fish species in China Seas,characterized by wide distribution,seasonal migration,spawning all year *** long-term high fishing pressure,the biological traits of largehead hair-tail have changed,such as miniaturization,smaller size-at-age and earlier *** explore its current biological charac-ters,we analyzed age,growth and maturation of largehead hairtail in the East China Sea by analyzing the otolith microstructure and *** results showed that largehead hairtail is mainly composed of 1 year and 2 years old *** estimated von Ber-talanffy growth function(VBGF)showed significant differences between sexes,and asymptotic pre-anal length of male is longer than that of *** spawning seasons were observed in spring and autumn by monthly gonadosomatic index(GSI).Compared to historic survey data,the average pre-anal length at age decreased and size-at-maturation became smaller in the East China *** study updates life history parameters of largehead hairtail,and provides a reference for the present status of largehead hairtail,which can contribute to largehead haritail stock assessment and sustainable utilization in the China Seas.

关键词： Trichiurus japonicus East China Sea age growth maturation

Impact of Droughts on Winter Wheat Yield in Different Growth Stages during 2001–2016 in Eastern China

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International Journal of Disaster Risk Science 2018年第3期9卷 376-391页

作者： Huiqian Yu Qiang Zhang peng sun Changqing Song Key Laboratory of Environmental Change and Natural Disaster Ministry of Education Beijing Normal University Academy of Disaster Reduction and Emergency Management Ministry of Emergency Management and Ministry of Education Beijing Normal University Faculty of Geographical Science Beijing Normal University College of Territorial Resource and Tourism Anhui Normal University

Remote sensing can provide near real-time and dynamic monitoring of drought. The drought severity index(DSI), based on the normalized difference vegetation index(NDVI) and evapotranspiration/potential evapotranspiration(ET/PET), has been used for drought monitoring. This study examined the relationship between the DSI and winter wheat yield for prefecture-level cities in five provinces of eastern China during 2001–2016. We first analyzed the spatial and temporal distribution of droughts in the study area. Then the correlation coefficient between drought-affected area and detrended yield of winter wheat was quantified and the impact of droughts of different intensities on winter wheat yield during different growth stages was investigated. The results show that incipient drought during the wintering period has no significant impact on the yield of winter wheat, while moderate drought in the same period can reduce yield. Drought affects winter wheat yield significantly during the flowering and filling stages. Droughts of higher intensity have more significant negative effects on the yield of winter wheat. Monitoring of droughts and irrigation is critical during these periods to ensure normal yield of winter wheat. This study has important practical implications for the planning of irrigation and food security.

关键词： China Drought intensity Drought severity index Winter wheat crop yields

Cascade of Random Rotation and Scaling in a Shell Model Intermittent Turbulence

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Communications in Theoretical Physics 2006年第6X期46卷 1074-1080页

作者： sun peng CHEN Shi-Gang WANG Guang-Rui Graduate School of China Academy of Engineering Physics P.O. Box 2101 Beijing 100088 China Physics Department Anshan Normal College Anshan 1140057 China Institute of Applied Physics and Computational Mathematics P.O. Box 8009 (28) Beijing 100088 China

The time behaviors of intermittent turbulence in Gledzer-Ohkitani-Yamada model are investigated. Two kinds of orbits of each shell which is in the inertial range are discussed by portrait analysis in phase space. We find intermittent orbit parts wandering randomly and the directions of unstable quasi-periodic orbit parts of different shells form rotational, reversal and locked cascade of period three with shell number. We calculate the critical scaling of intermittent turbulence and the extended self-similarity of the two parts of orbit and point out that nonlinear scaling in inertial-range is decided by intermittent orbit parts.

关键词： intermittent orbit unstable quasi-periodic orbit critical scaling extended self-similarity (ESS)

Distribution Characteristics of Fat Greenling(Hexagrammos otakii) Inhabiting Artificial Reefs Around Qiansandao Island, Haizhou Bay, China

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Journal of Ocean University of China 2019年第5期18卷 1227-1234页

作者： WANG Xinmeng sun peng TANG Yanli LIANG Zhenlin College of Fisheries Ocean University of ChinaQingdao 266003China Marine College Shandong UniversityWeihai 264209China

Chinese government has provided vigorous financial supports to artificial reef(AR)projects to repair marine *** AR,an important AR project of Fishery Resource Restoration Program in Shandong Province,was built during 2002 to *** has enhanced the local fishery harvest and generated positive economic *** greenling(Hexagrammos otakii)is a major commercial reef fish in Qiansandao with high economic *** distribution characteristics need to be further *** this research,we studied the potential influence of environmental variables and distance from ARs on catch per unit effort(CPUE)and body length of fat *** results showed that the average body length of fat greenlings distributed within 10 m from ARs was longer than that of fat greenlings distributed more than 600 m away from *** length also increased with the increased salinity,while it declined as temperature *** probability of the presence of fat greenling increased when temperature was below 20℃,then it slightly *** decreased as the distance *** results elucidate the potential effects of environmental variables and distance from ARs on the distribution of fat greenling,which may also be helpful to the distribution research of other reef fish species.

关键词： Hexagrammos otakii spatial distribution distance environmental predictor artificial reef

Orthogonal modular biosynthesis of nanoscale conjugate vaccines for vaccination against infection

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Nano Research 2022年第2期15卷 1645-1653页

作者： Xin Li Chao Pan peng sun Zhehui peng Erling Feng Jun Wu Hengliang Wang Li Zhu State Key Laboratory of Pathogen and Biosecurity Beijing Institute of BiotechnologyBeijing 100071China

Conjugate vaccines represent one of the most effective means for controlling the occurrence of bacterial *** nanotechnology has been greatly applied in the field of vaccines,it is seldom used for conjugate vaccine research because it is very difficult to connect polysaccharides and *** this work,an orthogonal and modular biosynthesis method was used to produce nanoconjugate vaccines using the SpyTag/SpyCatcher *** SpyTag/SpyCatcher system is combined with protein glycosylation technology,bacterial O-polysaccharide obtained from Shigela flexneri 2a can be conjugated onto the surfaces of different virus-like particles(VLPs)in a biocompatible and controlled *** confirming the excellent lymph node targeting and humoral immune activation abilities,these nanoconjugate vaccines further induced efficient prophylactic effects against infection in a mouse *** results demonstrated that natural polysaccharide antigens can be easily connected to VLPs to prepare highly efficient nanoconjugate *** the best of the researchers1 knowledge,this is the first time VLP-based nanoconjugate vaccines are produced efficiently,and this strategy could be applied to develop various pathogenic nanoconjugate vaccines.

关键词： Shigela flexneri 2a O-polysaccharide virus-like particle SpyTag/SpyCatcher system nanoconjugate vaccines

Chiral edge state coupling theory of transport in quantum anomalous Hall insulators

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Science China(Physics,Mechanics & Astronomy) 2023年第8期66卷 101-107页

作者： Rui Chen Hai-peng sun Bin Zhou Dong-Hui Xu Department of Physics Hubei UniversityWuhan 430062China Institute for Theoretical Physics and Astrophysics University of WurzburgWurzburg 97074Germany Departmentof Physicsand Chongqing Key Laboratory for Strongly Coupled Physics Chongqing UniversityChongqing 40044China Center of Quantum Materials and Devices Chongqing UniversityChongqing 400044China

The quantum anomalous Hall effect is characterized by a quantized Hall resistance with a vanishing longitudinal *** experiments reported the quantization of the Hall resistance,which is always accompanied by a non-vanishing longitudinal resistance that is several k?.Meanwhile,the non-vanishing longitudinal resistance exhibits a universal exponential decay with the increase in magnetic *** propose that the coupling of chiral edge states,which has not been properly evaluated in the previous theories,can give rise to the non-vanishing longitudinal *** coupling between the chiral edges states along the opposite boundaries can be assisted by magnetic domains or defects inside the sample bulk,which has been already identified in recent *** theory provides a potential mechanism to understand the experimental result in both magnetic topological insulator and moirésuperlattice systems.

关键词： quantum anomalous Hall effect quantum transport chiral edge state coupling

Tadpole-shaped polymers based on UV-induced strain promoted azide-alkyne cycloaddition reaction

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Science China Chemistry 2016年第10期59卷 1277-1282页

作者： Jinghui Hu peng sun Xiubo Jiang Wen Zhu Ke Zhang Key Laboratory of Rubber-Plastics Ministry of Education Shandong Provincial Key Laboratory of Rubber-Plastics School of Polymer Science and EngineeringQingdao University of Science and TechnologyQingdao 266042China State Key Laboratory of Polymer Physics and Chemistry Institute of ChemistryChinese Academy of SciencesBeij'ing 100190China

In the present study, we synthesized well-defined tadpole-shaped polystyrene(PS) via the combination of atom transfer radical polymerization(ATRP) and UV-induced strain promoted azide-alkyne cycloaddtion(SPAAC) reaction. A di-bromo ATRP initiator(Br-ini-Br) containing cyclopropenone-masked dibenzocyclooctyne group was used to prepare the linear PS with a cyclopropenone-masked dibenzocyclooctyne in the middle of the chain and bromo groups at both ends(Br-PS-Br). Then we used the single electron transfer-nitroxide radical coupling(SET-NRC) reaction to transfer the bromo end groups to azide groups(N_3-PS-N_3). After UV irradiation, the dibenzocyclooctyne group was quantitatively released, and intramolecularly reacted with alternative azide end group to produce the tadpole-shaped PS based on SPAAC reaction.

关键词： atom transfer radical polymerization tadpole-shaped UV-induced strain promoted azide-alkyne cycloaddition reaction

Influence of Parasitic Parameters on Dynamic Threshold Voltage Hysteresis of Silicon Carbide MOSFETs

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CSEE Journal of Power and Energy Systems 2023年第6期9卷 2251-2262页

作者： Yumeng Cai Tong sun peng sun Zhibin Zhao Xuebao Li Hui Wang Zhong Chen Boyuan Cao the State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources North China Electric Power UniversityBeijing 102206China the Department of Electrical Engineering University of ArkansasFayettevilleAR 72701USA the Electric Power Research Institute State Grid Shanghai Electric Power CompanyShanghai 200437China

Threshold voltage (V_(TH)) hysteresis affects the dynamic characteristics of silicon carbide (SiC) MOSFETs, whichin turn affects reliability of a device. In this paper, a dynamichysteresis curve is proposed as an evaluation method of theinfluence of V_(TH) hysteresis on the switching characteristics ofSiC MOSFETs. This method can eliminate the impact of triggerlevel and obtain the dynamic V_(TH). Furthermore, the influence ofparasitic parameters on dynamic V_(TH) hysteresis is theoreticallyanalyzed. Double pulse tests under different parasitic parametersare performed on three SiC MOSFETs with different gatestructures to verify the analysis. Results show that gate resistance(R_(G)) and source inductance (L_(S)) have more significant effectson dynamic V_(TH) hysteresis compared with gate inductance anddrain inductance. V_(TH) hysteresis phenomenon weakens withincrease of R_(G) or L_(S), which is related to device *** results presented in this paper can provide guidance forthe design of circuit parasitic parameters of SiC MOSFETs toregulate V_(TH) hysteresis.

关键词： Dynamic hysteresis curve parasitic parameters silicon carbide(SiC)MOSFETs switching characteristics threshold voltage hysteresis