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An application of interacting shear flows theory: exact solution for unsteady oblique stagnation point flow

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Acta Mechanica Sinica 2006年第5期22卷 397-402页

作者： Guibo Li Minguo dai Z. gao College of Physical and Environmental Oceanography Ocean University of China Qingdao 266003 China LHD Institute of Mechanics Chinese Academy of Sciences Beijing 100080 China

An analytical solution of the governing equations of the interacting shear flows for unsteady oblique stagnation point flow is obtained. It has the same form as that of the exact solution obtained from the complete NS... 详细信息

关键词： Navier-Stokes equations Interacting shear flows Unsteady oblique stagnation point flow Exact solution

Responses of a resident group to an outsider in the blue-breasted quail: A paradigm for studying social resettlement of dispersers

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Current Zoology 2023年第3期69卷 236-243页

作者： Shumei zi Lifang gao Xiaoxue Chen Qian wang fangyuan Liu Jianchuan Li Bo Du College of Ecology Lanzhou UniversityTianshui Sourth Road 222#Lanzhou City 730000GansuChina School of Life Sciences Lanzhou UniversityTianshui Sourth Road 222#Lanzhou City 730000GansuChina Cuiying Honors College Lanzhou UniversityTianshui Sourth Road 222#Lanzhou City 730000GansuChina Tibet Museum of Natural Science Zangda East Road 9#Lhasa City 850000Tibet Autonomous RegionChina

Dispersal is an individual life-history trait that can influence the ecological and evolutionary dynamics of both the source and recipient *** studies of animal dispersal have paid little attention to how the responses of residents in a recipient population affect the social resettlement of dispersers into a new *** addressed this question in the blue-breasted quail Synoicus chinensis by designing an outsider introduction experiment to simulate a scenario of interaction between residents and *** the experiment,we introduced an unfamiliar quail into a group of 3 differently ranked residents and then examined their behavioral responses to the arrival of the *** found that all residents made negative responses by pecking at the outsider to maintain their pecking order,in which high-ranked residents displayed significantly greater intensity than those of lower *** result highlighted that adverse behavioral responses of residents would prevent outsiders from obtaining hierarchical dominance in the recipient ***,the residents’sex ratio,their relative ages to the outsiders,and whether outsiders counter-pecked at the residents all influenced the probability of outsiders prevailing against the *** outsiders that displayed counter-peck courage were more likely to gain higher dominance and hence resettle into the recipient group *** findings suggest that resident groups may impose a selection among dispersers via adverse behavioral ***,social factors that can influence the resettlement step of dispersers in a new habitat should be accounted for in future studies of animal dispersal.

关键词： dispersal pecking order recipient population resident group Synoicus chinensis

In Situ Synthesis of Heat Resistant Gradient Composite on Steel Surface

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Journal of Iron and Steel Research International 2009年第2期16卷 89-94页

作者： CUI Xiang-hong wang Feng wang Shu-qi YANG zi-run gao Ming-juan WEI Min-xian School of Materials Science and Engineering Jiangsu University Zhenjiang 212013 Jiangsu China

A heat resistant gradient composite was synthesized in situ on steel with the self-propagating high temperature synthesis （SHS） reaction of 3Ni-Al-Ti-C system during casting. The phases, microstructure, and composition of the composite were analyzed by using an X-ray diffractometer （XRD）, and a scanning electron microscope （SEM） coupled with an energy-dispersive X-ray spectroscope （EDS）. The formation mechanism of the composite is also discussed. TiC/Ni3 Al/steel gradient composite is achieved by forming the gradient distributions of Fe, Ni, and Al, accompanied with the gradient variation of the microstructure from TiC/Nia A1, to TiC/Ni3 Al/steel, and to steel. The composite is in situ synthesized through whole reaction of 3Ni-Al-Ti-C system in liquid steel and densification procedure, and the liquid steel infiltrates into pores in the SHS product and forces liquid Ni3Al to form self-compaction further.

关键词： steel heat resistant composite synthesis microstructure

PtNiCu nanowires with advantageous lattice-plane boundary for enhanced ethanol electrooxidation

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Nano Research 2022年第4期15卷 2877-2886页

作者： Shuna Li Yao wang Yunrui Li Xu fang Yujie Liu Mingxuan Li Zhen wang Yufeng gao Haixiao Sun Fei gao Xin Zhang Xiaoping dai State Key Laboratory of Heavy Oil Processing College of Chemical Engineering and EnvironmentChina University of PetroleumBeijing 102249China Department of Chemistry Tsinghua UniversityBeijing 100084China Jiangsu Key Laboratory of Vehicle Emissions Control School of the EnvironmentCenter of Modern AnalysisKey Laboratory of Mesoscopic Chemistry of Ministry of Education of ChinaSchool of Chemistry and Chemical EngineeringNanjing UniversityNanjing 210093China

It is generally accepted that the interface effect and surface electronic structure of catalysts have vital impact on catalytic *** and tailoring the atomic arrangement of interface structure are of great importance for ***,we proposed a simple method to synthesize etching-PtNiCu nanowires(e-PtNiCu NWs)enclosed by both(110)and(100)facets evolving from PtNiCu nanowires(PtNiCu NWs)mainly with(111)facets by selectively etching *** acetic acid etching treatment,the e-PtNiCu NWs possess high total proportions(88.3%)of(110)and(100)facets,whereas the(111)facet is dominant in PtNiCu NWs(64%)by qualitatively and quantitatively *** the structure characterizations and performance tests of ethanol electrooxidation reaction(EOR),we find that the e-PtNiCu NWs display remarkably performance for EOR,which is nearly 4.5 times and 1.5 times enhancement compared with the state-of-the-art Pt/C catalyst,as well as 2.2 and 1.4 times of PtNiCu NWs,in specific activity and mass activity,*** improved performance of e-PtNiCu NWs is attributed to synergistic catalytic effect between(110)and(100)facets that not only significantly decreases the onset potentials of adsorbed CO(CO_(ads))but also favors the oxidation of CO_(ads)on the surface of ***,thermodynamics and kinetic studies indicate that the synergistic effect of both(110)and(100)facets in e-PtNiCu NWs can decrease the activation energy barrier and facilitate the charge transfer during the *** work provides a promising approach to construct catalysts with tunable surface electronic structure towards efficient electrocatalysis.

关键词： chemical etching crystal-facet engineering synergistic effect ethanol electrooxidation CO resistibility

Hypergraph Computation

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Engineering 2024年第9期40卷 188-201页

作者： Yue gao Shuyi Ji Xiangmin Han Qionghai dai School of Software Tsinghua UniversityBeijing 100084China

Practical real-world scenarios such as the Internet,social networks,and biological networks present the challenges of data scarcity and complex correlations,which limit the applications of artificial *** graph structure is a typical tool used to formulate such correlations,it is incapable of modeling highorder correlations among different objects in systems;thus,the graph structure cannot fully convey the intricate correlations among *** with the aforementioned two challenges,hypergraph computation models high-order correlations among data,knowledge,and rules through hyperedges and leverages these high-order correlations to enhance the ***,hypergraph computation achieves collaborative computation using data and high-order correlations,thereby offering greater modeling *** particular,we introduce three types of hypergraph computation methods:①hypergraph structure modeling,②hypergraph semantic computing,and③efficient hypergraph *** then specify how to adopt hypergraph computation in practice by focusing on specific tasks such as three-dimensional(3D)object recognition,revealing that hypergraph computation can reduce the data requirement by 80%while achieving comparable performance or improve the performance by 52%given the same data,compared with a traditional data-based method.A comprehensive overview of the applications of hypergraph computation in diverse domains,such as intelligent medicine and computer vision,is also ***,we introduce an open-source deep learning library,DeepHypergraph(DHG),which can serve as a tool for the practical usage of hypergraph computation.

关键词： High-order correlation Hypergraph structure modeling Hypergraph semantic computing Efficient hypergraph computing Hypergraph computation framework

Comparative Studies on Hydrophilic and Hydrophobic Segments Grafted Poly(vinyl chloride)

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Chinese Journal of Polymer Science 2018年第5期36卷 604-611页

作者： Yan Zhang zi-Peng Yuan Yu Qin Ji dai Tao Zhang Department of Biomedical Engineering College of Engineering and Applied Sciences Nanjing University

Poly（vinyl chloride）（PVC） is one of the mostly produced plastics in the world and is widely used in single-use medical devices. However, the additives that are often necessary for PVC arouse concerns of its safety, thus quests the modifications of PVC itself. In this study, poly（ethylene glycol）（PEG） and polydimethylsiloxane（PDMS） segments were grafted onto PVC backbone in similar ways, and the chemical structures of the modified PVCs were characterized by Fourier transform infrared spectra, X-ray photoelectron spectra, thermogravimetric analysis and differential scanning calorimetry. Moreover, the water contact angle, protein adsorption, platelet adhesion, cell attachment and proliferation on different material surfaces were studied and compared. It was found that both PEG and PDMS grafting yielded improvement on biocompatibility compared with bare PVC, while hydrophobic PDMS grafted PVC showed more effective on cell attachment and proliferation than that of hydrophilic PEG grafted PVC.

关键词： Poly(vinyl chloride) Poly(ethylene glycol) Polydimethylsiloxane Grafting Biomedical properties

Construction of Influenza Early Warning Model Based on Combinatorial Judgment Classifier:A Case Study of Seasonal Influenza in Hong Kong

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Current Medical Science 2022年第1期42卷 226-236页

作者： zi-xiao wang James NTAMBARA Yan LU Wei dai Rui-jun MENG Dan-min QIAN Department of Medical Informatics School of MedicineNantong UniversityNantong 226001China Department of Computer Science College of Engineering and Computing SciencesNew York Institute of TechnologyNew York 10023USA Department of Computer Science College of Overseas EducationNanjing University of Posts and TelecommunicationsNanjing 210023China Department of Epidemiology School of Public HealthNantong UniversityNantong 226019China Artificial Intelligence Laboratory Center De Montfort University of LeicesterLeicester LE1 9BHUnited Kingdom

Objective:The annual influenza epidemic is a heavy burden on the health care system,and has increasingly become a major public health problem in some areas,such as Hong Kong(China).Therefore,based on a variety of machine learning methods,and considering the seasonal influenza in Hong Kong,the study aims to establish a Combinatorial Judgment Classifier(CJC)model to classify the epidemic trend and improve the accuracy of influenza epidemic early warning.

关键词： influenza prediction data-driven Support Vector Machine Discriminant Analysis Ensemble Classifier

Periodically modulated interaction effect on transport of Bose–Einstein condensates in lattice with local defects

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Chinese Physics B 2019年第1期28卷 245-250页

作者： Kun-Qiang Zhu zi-fa Yu Ji-Ming gao Ai-Xia Zhang Hong-Ping Xu Ju-Kui Xue College of Physics and Electronics Engineering Northwest Normal UniversityLanzhou 730070China

We theoretically investigate the periodically modulated interaction effect on the propagation properties of a traveling plane wave in a Bose–Einstein condensate(BEC) trapped in a deep annular lattice with local defects both analytically and numerically. By using the two-mode ansatz and the tight-binding approximation, a critical condition for the system preserving the superfluidity is obtained analytically and confirmed numerically. We find that the coupled effects of periodic modulated atomic interactions, the quasi-momentum of the plane wave, and the defect can control the superfluidity of the system. Particularly, when we consider the periodic modulation in the system with single defect, the critical condition for the system entering the superfluid regime depends on both the defect and the momentum of the plane wave. This is different from the case for the system without the periodic modulation, where the critical condition is only determined by the defect. The modulation and quasi-momentum of the plane wave can enhance the system entering the superfluid regime. Interestingly, when the modulated amplitude/frequency, the defect strength, and the quasi-momentum of the plane wave satisfy a certain condition, the system will always be in the superfluid region. This engineering provides a possible means for studying the periodic modulation effect on propagation properties and the corresponding dynamics of BECs in disordered optical lattices.

关键词： Bose–Einstein condensate periodic modulation superfluidity lattice with defects

High-performance silicon−graphene hybrid plasmonic waveguide photodetectors beyond 1.55μm

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Light(Science & Applications) 2020年第1期9卷 1731-1741页

作者： Jingshu Guo Jiang Li Chaoyue Liu Yanlong yin Wenhui wang Zhenhua Ni Zhilei Fu Hui Yu Yang Xu Yaocheng Shi Yungui Ma Shiming gao Limin Tong Daoxin dai State Key Laboratory for Modern Optical Instrumentation Zhejiang Provincial Key Laboratory for Sensing TechnologiesCollege of Optical Science and EngineeringInternational Research Center for Advanced PhotonicsZhejiang UniversityZijingang Campus310058 HangzhouChina Ningbo Research Institute Zhejiang University315100 NingboChina Department of Physics and Key Laboratory of MEMS of the Ministry of Education Southeast University211189 NanjingChina College of Information Science and Electronic Engineering Zhejiang University310027 HangzhouZhejiangChina

Graphene has attracted much attention for the realization of high-speed photodetection for silicon photonics over a wide wavelength ***,the reported fast graphene photodetectors mainly operate in the 1.55μm wavelength *** this work,we propose and realize high-performance waveguide photodetectors based on bolometric/photoconductive effects by introducing an ultrathin wide silicon−graphene hybrid plasmonic waveguide,which enables efficient light absorption in graphene at 1.55μm and *** operating at 2μm,the present photodetector has a responsivity of ~70 mA/W and a setup-limited 3 dB bandwidth of >20 *** operating at 1.55μm,the present photodetector also works very well with a broad 3 dB bandwidth of >40 GHz(setup-limited)and a high responsivity of ~0.4 A/W even with a low bias voltage of−0.3 *** work paves the way for achieving highresponsivity and high-speed silicon-graphene waveguide photodetection in the near/mid-infrared ranges,which has applications in optical communications,nonlinear photonics,and on-chip sensing.

关键词： waveguide beyond performance