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Link reliability based hybrid routing for tactical mobile ad hoc network

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Journal of Systems Engineering and Electronics 2008年第2期19卷 259-267页

作者： Xie Xiaochuan Wei gang Wu Keping Wang gang Jia Shilou School of Electronic & Information Engineering South China Univ. of Technology Guangzhou 510640 P. R. China Guangzhou Haige Communications Group Incorporated Company Guangzhou 510656 P. R. China Communication Research Center Harbin Inst. of Technology Harbin 150001 P. R. China

Tactical mobile ad hoc network （MANET） is a collection of mobile nodes forming a temporary network, without the aid of pre-established network infrastructure. The routing protocol has a crucial impact on the network performance in battlefields. Link reliability based hybrid routing （LRHR） is proposed, which is a novel hybrid routing protocol, for tactical MANET. Contrary to the traditional single path routing strategy, multiple paths are established between a pair of source-destination nodes. In the hybrid routing strategy, the rate of topological change provides a natural mechanism for switching dynamically between table-driven and on-demand routing. The simulation results indicate that the performances of the protocol in packet delivery ratio, routing overhead, and average end-to-end delay are better than the conventional routing protocol.

关键词： tactical mobile ad hoc networks hybrid routing link reliability edge weight.

Construction of Ni single-atom coordinated with doped N and S elements for mild hydrogenation of methyl acrylate to methyl propionate

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Nano Research 2025年第1期18卷 217-224页

作者： Taolue Sun Chen Jian gang Wang Hui Zhao Guoliang Zhang Zengxi Li Chunshan Li State Key Laboratory of Mesoscience and Engineering CAS Key Laboratory of Green Process and EngineeringBeijing Key Laboratory of Ionic Liquids Clean ProcessInstitute of Process EngineeringChinese Academy of SciencesBeijing 100190China School of Chemical Engineering University of Chinese Academy of SciencesBeijing 100049China Huizhou Institute of Green Energy and Advanced Materials Huizhou 516081China Advanced Energy Science and Technology Guangdong Laboratory Huizhou 516081China

Although the nickel-based catalyst is able toexhibit comparative catalytic activity to noble metal formethyl acrylate hydrogenation,it requires strict reactioncondition,which can be improved by regulation ofcoordination *** this study,we constructed akind of Ni single-atom coordinated with N and S(Ni-NSC)through the pyrolysis of organic Ni-based precursors at600℃.The existence and fine structure of Ni single-atom were confirmed by the spherical electron microscopicobservation in combination with the X-ray absorption spectroscopy(XAS)*** addition,the catalytichydrogenation assessment suggested that the as-prepared Ni-NSC catalyst exhibited higher activity and stability than theNi/NSC supported catalyst prepared by incipient wetness impregnation *** remarkable catalytic activity was dueto the high dispersion and density of Ni single-atom and weak adsorption energy of intermediates on these Ni sites.

关键词： methyl acrylate mild hydrogenation Ni single-atom coordination environment adsorption energy

Electro-optical properties cholesteric liquid of polymer stabilized crystal film＊

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Chinese Physics B 2011年第2期20卷 295-301页

作者： Ma Ji Zheng Zhi-gang Liu Yong-gang Xuan Li State Key Laboratory of Applied Optics Changchun Institute of Optics Fine Mechanics and Physics Chinese Academy of Sciences Changchun 130033 China Department of Physics School of Science East China University of Science and Technology Shanghai 200237 China

Liquid crystals （LCs） and polymers are extensively used in various electro-optical applications. In this paper, normal mode polymer stabilized cholesteric LC film is prepared and studied. The effects of chiral dopant and monomer concentrations on the electro-optical properties, such as contrast ratio, driving voltage, hysteresis width and response time, are investigated. The reasons of electro-optical properties influenced by the concentrations of the materials are discussed. Through the proper material recipe, the electro-optical properties of polymer stabilized cholesteric LC film can be optimized.

关键词： liquid crystal polymer electro-optical property cholesteric liquid crystal

INVERSE MEDIUM SCATTERING PROBLEMS IN NEAR-FIELD OPTICS

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Journal of Computational Mathematics 2007年第3期25卷 252-265页

作者： gang Bao Peijun Li Department of Mathematics Michigan State UniversityEast LansingMI 48824USA Department of Mathematics University of MichiganAnn ArborMI 48109USA

A regularized recursive linearization method is developed for a two-dimensional in-verse medium scattering problem that arises in near-field optics, which reconstructs the scatterer of an inhomogeneous medium deposited on a homogeneous substrate from data accessible through photon scanning tunneling microscopy experiments. In addition to the ill-posedness of the inverse scattering problems, two difficulties arise from the layered back-ground medium and limited aperture data. Based on multiple frequency scattering data, the method starts from the Born approximation corresponding to the weak scattering at a low frequency, each update is obtained via recursive linearization with respect to the wavenumber by solving one forward problem and one adjoint problem of the Helmholtz equation. Numerical experiments are included to illustrate the feasibility of the proposed method.

关键词： Inverse medium scattering Helmholtz equation Near-field optics Recursivelinearization.

BRITTON CHANCE AND THE THERANOSTIC BEACON DEVELOPMENT AT PENN

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Journal of Innovative Optical Health Sciences 2011年第4期4卷 483-485页

作者： gang ZHENG Department of Medical Biophysics University of Toronto Canada

In the summer of 2000,while I was vacationing in China and getting ready to start my career in industry,I got a call from Jerry Glickson to check if I would be interested in joining the Penn Molecular Imaging *** was very persuasive and he drew an interesting outline of the work,including the opportunity to work with one of the greatest scientific minds in the *** could I say no to work with Britton Chance,aka"BC"?

关键词： Optical imaging photodynamic therapy chlorophyll cancer

Load Bearing Capacity and Safety Analysis for Strain-hardening Austenitic Stainless Steel Pressure Vessels

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Chinese Journal of Mechanical Engineering 2011年第2期24卷 179-186页

作者： CHEN gang DENG Yangchun China Special Equipment Safety Supervision Administration General Administration of Quality Supervision and Inspection and Quarantine of the People＇s Republic of China Beijing 100088 China Hubei Provincial Special Equipment Safety Inspection and Research Institute Wuhan 430077 China

By increasing the yield strengths of austenitic stainless steels for pressure vessels with strain hardening techniques,the elastic load bearing capacity of austenitic stainless steel pressure vessels can be significantly *** kinds of strain hardening methods are often used for austenitic stainless steel pressure vessels：Avesta model for ambient temperature applications and Ardeform model for cryogenic temperature *** methods are obtained from conventional design rules based on the linear elastic theory,and only consider the hardening effect from *** this limits the applications of strain hardening techniques for austenitic stainless steel pressure vessels because of safety *** paper investigates the effect of strain hardening on the load bearing capacity of austenitic stainless steel pressure vessels under large deformation,based on the elastic-plastic ***,to understand the effect of strain hardening on material behavior,the plastic instability loads of a round tensile bar specimen are derived under two different loading paths and validated by ***,to investigate the effect of strain hardening on pressure vessels strength, the plastic instability pressure under strain hardening is derived and further validated by finite element ***,the safety margin of pressure vessels after strain hardening is analyzed by comparing the safety factor values calculated from bursting tests,finite element analyses,and *** researching results show that the load bearing capacity of pressure vessels at ambient temperature is independent of the loading history when the effects of both material strain hardening and structural deformation are *** element simulations and bursting tests results show that the minimum safety factor of austenitic stainless steel pressure vessels with 5% strain hardening is close to the recommended value for common pressure vessels specified in th

关键词： pressure vessel austenitic stainless steel strain hardening load bearing capacity safety margin

Entrance Effect on Load Capacity of Orifice Compensated Aerostatic Bearing with Feeding Pocket

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Chinese Journal of Mechanical Engineering 2010年第4期23卷 451-459页

作者： LONG Wei BAO gang School of Mechatronics Engineering Harbin Institute of Technology Harbin 150001 China

The current research of the aerostatic thrust bearing mainly focuses on the porous material bearing and inherent compensated air bearing, which aims at obtaining small physical dimension and large load capacity. Although porous material bearing appears larger load capacity, materials anisotropy itself and void content distortion caused in heat-treating, and machining processes add greater complexity to internal flow transfer process. Inherent compensated air bearing has the advantages of simple structure and good stability, but its load capacity and static stiffness is not worth somewhat. In this paper, based on hydrostatic lubrication theory, finite volume method is presented for taking entrance effects into account in computing pressure distribution, load capacity and mass flow rates of circular aerostatic thrust bearings. Technical analysis, numerical simulations and laboratory demonstration tests of influence of pocket diameter and pocket depth on loading capacity of aerostatic thrust bearing are carried out on simple orifice compensated air bearings with feeding pockets. The static parameters, such as air consumption and pressure distributions, are measured as a function of supply pressure and air gap height for several different orifices and pockets size. Entrance effects are described in term of typical throttling types, and the effect of pocket diameter and pocket depth on load capacity is systematically described respectively. The proposed research results uncover the causation of throttling action of the orifice compensated air bearing with feed pocket and further develop and improve the design theory of air bearing.

关键词： aerostatic thrust bearing feeding pocket entrance effects

Sliding mode control of reaction flywheel-based brushless DC motor with buck converter

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Chinese Journal of Aeronautics 2013年第4期26卷 967-975页

作者： Liu gang Zhang Cong School of Instrumentation Science and Opto-electronics Engineering Beihang University

Reaction flywheel is a significant actuator for satellites＇ attitude control. To improve output torque and rotational speed accuracy for reaction flywheel, this paper reviews the modeling and control approaches of DC-DC converters and presents an application of the variable structure system theory with associated sliding regimes. Firstly, the topology of reaction flywheel is constructed. The small signal linearization process for a buck converter is illustrated. Then, based on the state averaging models and reaching qualification expressed by the Lee derivative, the general results of the sliding mode control （SMC） are analyzed. The analytical equivalent control laws for reaction flywheel are deduced detailedly by selecting various sliding surfaces at electromotion, energy consumption braking, reverse connection braking stages. Finally, numerical and experimental examples are presented for illustrative purposes. The results demonstrate that favorable agreement is established between the simulations and experiments. The proposed control strategy achieves preferable rotational speed regulation, strong rejection of modest disturbances, and high-precision output torque and rotational speed tracking abilities.

关键词： DC-DC converter Flywheels State averaging model Sliding mode control Sliding surface Topology

Stability Analysis of Systems With Time-varying Delay via a Novel Lyapunov Functional

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IEEE/CAA Journal of Automatica Sinica 2019年第4期6卷 1068-1073页

作者： Yun Chen gang Chen the School of Electrical and Information Engineering Hunan University of TechnologyZhuzhou 412007 the Key Laboratory for Electric Drive Control and Intelligent Equipment of Hunan Province Zhuzhou 412007China

This paper investigates the stability problem for time-varying delay *** obtain a larger delay bound,this paper uses the second-order canonical Bessel-Legendre(BL)***,using four couples of integral terms in the augmented Lyapunov-Krasovskii function(LKF)to enhance the relationship between integral functionals and other ***,unlike the construction of the traditional LKF,a novel augmented LKF is constructed with two new delayproduct-type terms,which adds more state information and leads to less conservative ***,two numerical examples are provided to demonstrate the effectiveness and the significant improvement of the proposed stability criteria.

关键词： Integral inequality Lyapunov theorem stability time-delay systems