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Nonlinear Sampled-Data Systems with a Generalized Hold Polynomial-Function for Fast Sampling Rates

Journal of Systems Science & Complexity 2019年第6期32卷 1572-1596页

作者： zeng cheng XIANG Shuwen HE Yi DING Qianqian College of Computer Science&Technology Guizhou UniversityGuiyang 550025China School of Science Guizhou Institute of TechnologyGuiyang 550003China School of Mathematics and Statistics Guizhou UniversityGuiyang 550025China College of Mathematics and Information Science Guiyang UniversityGuiyang 550005China

It is well-known that such non-conventional digital control schemes,such as generalized sampled-data hold functions,have clear advantages over the conventional single-rate digital control ***,they have theoretical negative aspects that deviation of the input can lead to intersample oscillations or intersample *** paper investigates the zero dynamics of sampleddata models,as the sampling period tends to zero,composed of a new generalized hold polynomial function,a nonlinear continuous-time plant and a sampler in *** a new design of generalized hold circuit,the authors give the approximate expression of the resulting sampled-data systems as power series with respect to a sampling period up to the some order term on the basis of the normal form representation for the nonlinear continuous-time systems,and remarkable improvements in the stability properties of discrete system zero dynamics may be achieved by using proper adj us *** particular interest are the stability conditions of sampling zero dynamics in the case of a new hold ***,an insightful interpretation of the obtained sampled-data models can be made in terms of minimal intersample ripple by design,where the ordinary multirate sampled systems have a poor intersample *** has shown that the intersample behavior arising from the multirate input polynomial function can be localised by appropriately selecting the design parameters based on the stability condition of the sampling zero *** results presen ted here generalize the well-known notion of sampling zero dynamics from the linear case to nonlinear systems.

关键词： Generalized hold polynomial function nonlinear sampled-data models stability Taylor approach zero dynamics

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Integration-centric approach to system readiness assessment based on evidential reasoning

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Journal of Systems Engineering and Electronics 2012年第6期23卷 881-890页

作者： Leilei Chang Mengjun Li Ben cheng Ping zeng School of Information System and Management National University of Defense Technology Changsha 410073 P. R. China

An integration-centric approach is proposed to handle inadequate information in the system readiness level （SRL） assessment using the evidential reasoning （ER） algorithm. Current SRL assessment approaches cannot be applied to handle inadequate information as the input. The ER-based approach is proposed to synthesize inadequate input information and an integration-centric perspective is applied to reduce the computational complexity. Two case studies are performed to validate the efficiency of the proposed approach. And these studies are also performed to study how the inadequate information will affect the assessment result. And the differences caused by the system＇s structure. The importance of the system＇s structure in the SRL assessment is demonstrated and the contributions made in this study are summarized as conclusions.

关键词： system readiness level (SRL) technology readinesslevel (TRL) integration readiness level (IRL) evidential reasoning(ER) integration-centric.

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Sawtooth-Like Graphene Nanoribbon

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Nano Research 2008年第1期1卷 40-45页

作者： Xiaojun Wu Xiao cheng zeng Department of Chemistry and Nebraska Center for Materials and Nanoscience University of Nebraska-LincolnLincolnNE 68588USA

Motivated by recent successful synthesize of segmented graphene nanoribbons(GNRs)with junctions,we explore electronic properties of a novel form of GNR with sawtooth-like structure using the density-functional theory *** is found that the unique edge structures of the sawtooth-like GNR induce richer band-gap features than the straight GNR counterpart with either armchair or zigzag *** effect of external electric fi eld on the electronic properties of the sawtooth-like GNR is also *** theoretical results may be useful for designing GNR-based fi eld-effect transistors.

关键词： Graphene nanoribbons sawtooth-like GNR straight GNR edge effect

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On Chaotification of Discrete Lagrange Systems

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Communications in Theoretical Physics 2006年第5期45卷 861-863页

作者： LI Guang-cheng YUE Bao-zeng Department of Mechanics Beijing Institute of Technology Beijing 100081 China

This paper is concerned with chaotification of discrete Lagrange systems in one dimension, via feedback control techniques. A chaotification theorem for discrete Lagrange systems is established. The controlled systems are proved to be chaotic in the sense of Devaney. In particular, the systems corresponding to the original systems and designed controllers are only required to satisfy, some mild assumptions.

关键词： discrete Lagrange systems chaotification anti-integrable limit

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Constructing Stable and Potentially High-Performance Hybrid Organic-Inorganic Perovskites with“Unstable”Cations

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Research 2020年第1期2020卷 228-237页

作者： Qing Yang Menghao Wu Xiao cheng zeng School of Physics Huazhong University of Science and TechnologyWuhanHubei 430074China Department of Chemistry University of NebraskaLincolnNE 68588USA

A new family of functional hybrid organic-inorganic perovskites(HOIPs)is theoretically designed based on the following chemical insights:when a proton is adhered to molecules like water or ethanol,the newly formed larger-sized cations(e.g.,H_(5)O_(2)^(+),C_(2)H_(5)OH_(2)^(+),and CH_(3)SH^(+))entail low electron affinities mimicking superalkalis;they are conjugated acids of weak bases that cannot survive in solution,while their chemistry behavior in the HOIP frameworks,however,may be markedly different due to greatly enhanced cohesive energies of the proton,which facilitate the formation of new ***-principles computations show that the putative formation reactions for these newly designed HOIPs typically release much more energy compared with the prevailing HOIP MAPbI3,suggesting the likelihood of facile solution-based fabrications,while the suppression of reverse formation suggests that the humidity stability may be markedly *** their formations,halide acids are unlikely to react with ethanol or methanethiol without the presence of metal halides,a condition further favoring their *** proposed structure of(H_(5)O_(2))PbI_(3)may also clarify the origin of the long-speculated existence of ***,density functional theory computations suggest that many of these HOIPs possess not only direct bandgaps with values within the optimal range for solar light absorbing but also more desirable optical absorption spectra than that of MAPbI3,where their ferroelectric polarizations also benefit *** stability and photovoltaic efficiency may be even further improved for the newly designed two-dimensional(2D)HOIPs and 2D/3D hybrid HOIP structures.

关键词： stability. stability bases

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Graphene-Like Bilayer Hexagonal Silicon Polymorph

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Nano Research 2010年第10期3卷 694-700页

作者： Jaeil Bai Hideki Tanaka Xiao cheng zeng Department of Chemistry and Nebraska Center for Materials and Nanoscience University of Nebraska-LincolnLincolnNebraska 68588USA Department of Chemistry Okayama UniversityOkayama 700-8530Japan

We present molecular dynamics simulation evidence for a freezing transition from liquid silicon to quasi-two-dimensional(quasi-2D)bilayer silicon in a slit *** new quasi-2D polymorph of silicon exhibits a bilayer hexagonal structure in which the covalent coordination number of every silicon atom is *** molecular dynamics simulations show that the stand-alone bilayer silicon(without the confinement)is still stable at 400 *** band-structure calculations suggest that the bilayer hexagonal silicon is a quasi-2D semimetal,similar to a graphene monolayer,but with an indirect zero band gap.

关键词： Bilayer hexagonal silicon slit pore semimetal two-dimensional polymorph

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The possibility of isolated target 3-D position estimation and optimal receiver position determination in SS-BSAR

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Science in China(Series F) 2008年第9期51卷 1372-1383页

作者： HU cheng LONG Teng zeng Tao Radar Research Lab Department of Electronic Engineering Beijing Institute of Technology Beijing 100081China

Starting from the generalized ambiguity function of bistatic SAR （BSAR）, it is shown that 3-D point target estimation can be carried out in space-surface bistatic SAR （SS-BSAR）. Appropriate analytical equations, based on maximum likelihood estimation （MLE）, are derived and confirmed via computer simulation. Furthermore, the performance of the estimate using the Crammer-Rao bound is analyzed for the case in question, thus further revealing the possibility and potential of target 3-D position estimation. Setting the determinant maximum of the information matrix as the criterion, the optimal receiver position and multi-receiver configuration are analytically determined in the SS-BSAR system. Simulation results also validate the correctness of the analytical calculation.

关键词： SS-BSAR position estimation MLE Crammer-Rao bound optimal receiver position

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Thermal transport in phosphorene and phosphorene-based materials:A review on numerical studies

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Chinese Physics B 2018年第3期27卷 60-71页

作者： Yang Hong Jingchao Zhang Xiao cheng zeng Department of Chemistry University of Nebraska-LincolnLincolnNE 68588USA Holland Computing Center University of Nebraska-LincolnLincolnNE 68588US

The recently discovered two-dimensional(2D)layered material phosphorene has attracted considerable interest as a promising p-type semiconducting *** this article,we review the recent advances in numerical studies of the ther-mal properties of monolayer phosphorene and phosphorene-based *** first briefly review the commonly used first-principles and molecular dynamics(MD)approaches to evaluate the thermal conductivity and interfacial thermal resistance of 2D *** of different steady-state and transient MD techniques have been elaborated on in ***,we discuss the anisotropic thermal transport of phosphorene in zigzag and armchair chiral ***-quently,the in-plane and cross-plane thermal transport in phosphorene-based heterostructures such as phosphorene/silicon and phosphorene/graphene is ***,the numerical research in the field of thermal transport in 2D phospho-rene is highlighted along with our perspective of potentials and opportunities of 2D phosphorenes in electronic applications such as photodetectors,field-effect transistors,lithium ion batteries,sodium ion batteries,and thermoelectric devices.

关键词： thermal conductivity interracial thermal resistance first-principles molecular dynamics

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Targeted and activatable nanosystem for fluorescent and optoacoustic imaging of immune-mediated inflammatory diseases and therapy via inhibiting NF-κB/NLRP3 pathways

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Bioactive Materials 2022年第4期7卷 79-92页

作者： Lihe Sun Juan Ouyang Zhuo zeng cheng zeng Yunqing Ma Fang zeng Shuizhu Wu Biomedical Division State Key Laboratory of Luminescent Materials and DevicesGuangdong Provincial Key Laboratory of Luminescence from Molecular AggregatesCollege of Materials Science and EngineeringSouth China University of TechnologyGuangzhou510640China

Immune-mediated inflammatory diseases(IMIDs)represent a diverse group of diseases and challenges remain for the current ***,we present an activatable and targeted nanosystem for detecting and imaging IMIDs foci and treating them through blocking NF-κB/NLRP3 pathways.A ROS-activatable prodrug BH-EGCG is synthesized by coupling a near-infrared chromophore with the NF-κB/NLRP3 inhibitor epigallocatechin-3-gallate(EGCG)through boronate bond which serves as both the fluorescence quencher and ROS-responsive ***-EGCG molecules readily form stable nanoparticles in aqueous medium,which are then coated with macrophage membrane to ensure the actively-targeting capability toward inflammation ***,an antioxidant precursor N-acetylcysteine is co-encapsulated into the coated nanoparticles to afford the nanosystem BH-EGCG&NAC@MM to further improve the anti-inflammatory *** from the inflammation-homing effect of the macrophage membrane,the nanosystem delivers payloads(diagnostic probe and therapeutic drugs)to inflammatory lesions more efficiently and releases a chromophore and two drugs upon being triggered by the overexpressed in-situ ROS,thus exhibiting better theranostic performance in the autoimmune hepatitis and hind paw edema mouse models,including more salient imaging signals and better therapeutic efficacy via inhibiting NF-κB pathway and suppressing NLRP3 inflammasome *** work may provide perceptions for designing other actively-targeting theranostic nanosystems for various inflammatory diseases.

关键词： Actively-targeting nanosystem Immune-mediated inflammatory disease Two-mode imaging NF-κB/NLRP3 pathways

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Gravitational wave radiation from a double white dwarf system inside our galaxy: a potential method for seeking strange dwarfs

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Research in Astronomy and Astrophysics 2009年第7期9卷 745-750页

作者： Zhan-Kui Lu Shi-Wei Wu Zhi-cheng zeng Department of Astronomy Nanjing University Nanjing 210008 China

Like the investigation of double white dwarf （DWD） systems, strange dwarf （SD） - white dwarf （WD） system evolution in Laser Interferometer Space Antenna （LISA）＇s absolute amplitude-frequency diagram is investigated. Since there is a strange quark core inside an SD, SDs＇ radii are significantly smaller than the value predicted by the standard WD model, which may strongly affect the gravitational wave （GW） signal in the mass-transferring phases of binary systems. We study how an SD-WD binary evolves across LISA＇s absolute amplitude-frequency diagram. In principle, we provide an executable way to detect SDs in the Galaxy＇s DWD systems by radically new windows offered by GW detectors.

关键词： accretion accretion disks - binaries close - dense matter - gravitational waves

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