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The research of cooperative routing algorithm in mobile Ad hoc networks

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The Journal of China Universities of Posts and Telecommunications 2006年第3期13卷 5-10页

作者： CHEN Chao zheng Bao-yu ZHAO xian-jing Institute of Signal and Information Processing Nanjing University of Posts and Telecommunications Nanjing 210003 China

Cooperative routing technology can efficiently improve the performance of the network by initiatively selecting cooperative nodes to forward the data. In this article, cooperative routing algorithms are proposed and implemented based on three different criteria： optimal channel state, maximal remaining energy, and the shortest path. The simulation based on network simulation （NS） compares the performance of the proposed algorithms with non-cooperative destination-sequenced distancevector （DSDV） protocol. The results reveal that cooperative algorithms outperform DSDV routing protocol with distinctive gains at the cost of sacrificing acceptable normalized network load.

关键词： cooperative routing crosslayer DSDV routing protocol Ad hoc networks

Molecular dynamics for the charging behavior of nanostructured electric double layer capacitors containing room temperature ionic liquids

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Nano Research 2015年第3期8卷 931-940页

作者： xian Kong Diannan Lu zheng Liu Jianzhong Wu Department of Chemical and Environmental Engineering University of California Riverside CA 9252 I USA Department of Chemical Engineering Tsinghua University Beijing 100084 China

The charging kinetics of electric double layers （EDLs） is closely related to the performance of a wide variety of nanostructured devices including supercapacitors, electro-actuators, and electrolyte-gated transistors. While room temperature ionic liquids （RTIL） are often used as the charge carrier in these new applications, the theoretical analyses are mostly based on conventional electrokinetic theories suitable for macroscopic electrochemical phenomena in aqueous solutions. In this work, we study the charging behavior of RTIL-EDLs using a coarse-grained molecular model and constant-potential molecular dynamics （MD） simulations. In stark contrast to the predictions of conventional theories, the MD results show oscillatory variations of ionic distributions and electrochemical properties in response to the separation between electrodes. The rate of EDL charging exhibits non-monotonic behavior revealing strong electrostatic correlations in RTIL under confinement.

关键词： electric double layer room temperature ionicliquids nanostructured capacitor charging dynamics

Dynamic Event-Triggered Scheduling and Platooning Control Co-Design for Automated Vehicles Over Vehicular Ad-Hoc Networks

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IEEE/CAA Journal of Automatica Sinica 2022年第1期9卷 31-46页

作者： Xiaohua Ge Shunyuan Xiao Qing-long Han xian-Ming Zhang Derui Ding Computing and Engineering Technologies Swinburne University of TechnologyMelbourneVIC 3122Australia

This paper deals with the co-design problem of event-triggered communication scheduling and platooning control over vehicular ad-hoc networks(VANETs)subject to finite communication ***,a unified model is presented to describe the coordinated platoon behavior of leader-follower vehicles in the simultaneous presence of unknown external disturbances and an unknown leader control *** such a platoon model,the central aim is to achieve robust platoon formation tracking with desired inter-vehicle spacing and same velocities and accelerations guided by the leader,while attaining improved communication *** this aim,a novel bandwidth-aware dynamic event-triggered scheduling mechanism is *** salient feature of the scheduling mechanism is that the threshold parameter in the triggering law is dynamically adjusted over time based on both vehicular state variations and bandwidth ***,a sufficient condition for platoon control system stability and performance analysis as well as a co-design criterion of the admissible event-triggered platooning control law and the desired scheduling mechanism are ***,simulation results are provided to substantiate the effectiveness and merits of the proposed co-design approach for guaranteeing a trade-off between robust platooning control performance and communication efficiency.

关键词： Automated vehicles dynamic event-triggered communication information flow topology platooning control vehicular ad-hoc networks(VANETs)

Weighted cooperative routing for wireless mobile Ad-hoc network

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The Journal of China Universities of Posts and Telecommunications 2007年第1期14卷 16-21页

作者： ZHAO xian-jing zheng Bao-yu CHEN Chao Institute of Signal and Information Processing Nanjing University of Posts and Telecommunications Nanjing 210003 China

A novel weighted cooperative routing algorithm （WCRA） is proposed in this article, which was on the basis of a weighted metric with maximal remaining energy （MRE） of the relays and the maximal received SNR （MRS） of the nodes. Moreover, a cooperative routing protocol was implemented on the basis of WCRA. Then simulation is done on network simulation （NS-2） platform to compare the performances of MRS, MRE and WCRA with that of noncooperative destination-sequenced destination-sequenced distance-vector （DSDV） protocol. The simulative results show that WCRA obtains a performance tradeoff between MRE and MRS in terms of delivery ratio and network lifetime, which can effectively improve the network lifetime at an acceptable loss of delivery ratio.

关键词： weighted cooperative routing Ad-hoc networks,quality of service DSDV routing protocol

Synthesis and ion exchange properties for Cs^+ of ammonium-type mordenite

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Rare Metals 2015年第10期34卷 752-756页

作者： Dian-Quan Dong Jian-Guo zheng xian-Lian Han College of Chemical Engineering School of Qingdao University of Science and Technology

Cesium content in the seawater is 3.0 9 10-4 mg·L-1, and ammonium-type mordenite was used to exchange cesium from cesium source. K-type mordenite was obtained by hydrothermal synthesis method. After ammonium-modified, ion exchange properties such as saturated ion exchange capacities and selectivity coefficients for alkali metal ions were determined. At the same time, ion exchange isothermal curves of ammonium-type mordenite for Cs+ and NH4+ were determined at 25°*** electrolyte solution theory was used to work out activity coefficients of the system, and the Kielland diagram of the ion exchange system was obtained. The calculated equilibrium constant(Ka) and ion free enthalpy(DG0) of mordenite for Cs+ and NH4+ are 1.455 and -930.3J·mol-1, respectively, indicating that ion exchange process of ammonium-type mordenite for cesium is a spontaneous process.

关键词： Ion exchange Thermodynamics Mordenite Cesium

Italicized carbon nanotube facilitating water transport:a molecular dynamics simulation

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Science Bulletin 2015年第18期60卷 1580-1586页

作者： Jipeng Li xian Kong Diannan Lu zheng Liu State Key Laboratory for Chemical Engineering Department of Chemical Engineering Tsinghua University

While the preferential movement of water inside carbon nanotube is appealing for water purification,our understanding of the water transport mechanism through carbon nanotube(CNT)-based membrane is far from adequate. Here we conducted molecular dynamics simulations to study how the alignment of the CNTs in the membrane affects the water transport through the CNT membrane. It was shown that compared to the conventional CNT membrane where the alignment of CNTs was vertical to membrane surface, the ‘‘italicized CNT membrane'' in which the contact angel between membrane surface and the CNT alignment is not 90° offered a higher transmembrane flux of water. The expanded exposure of more carbon atoms to water molecules reduced the energy barrier near the entrance of this italicized CNT membrane, compared to the vertical one. For water flows through the italicized CNT membrane, the Lennard-Jones interaction between water and nanotube as function of central path of the CNT changes from ‘‘U'' to ‘‘V'' pattern, which significantly lowers energy barrier for filling water into the CNT,favoring the water transport inside carbon nanotube. Above simulation indicates new opportunities for applying CNT in water purification or related fields in which water transport matters.

关键词： Carbon nanotube Water desalination Molecular dynamics simulation

Highly Improved Creep Resistance in Polypropylene Through Thermally Reduced Graphene Oxide and Its Creep Lifetime Prediction

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Chinese Journal of Polymer Science 2024年第2期42卷 256-266,I0010页

作者： Can-Can Zhang Jun-long Yang Ya-Jiang Huang Guang-xian Li College of Polymer Science and Engineering State Key Laboratory of Polymer Materials Engineering of ChinaSichuan UniversityChengdu610065China

Polypropylene(PP) exhibits suboptimal creep resistance due to the presence of methyl groups on its main chain, leading to irregular chain segment distribution, diminished inter-chain interaction, and crystallinity. This structural feature causes chain slippage in PP under stress,significantly constraining its service lifetime. In this study, thermally reduced graphene oxide(TrGO) nanosheets were incorporated into the PP matrix, yielding a nanocomposite with exceptional creep resistance performance. Results demonstrated that at a stress of 25 MPa, a 2.0 wt% TrGO content could enhance the creep failure lifetime of PP by 21.5 times compared to neat PP. Rheology, transmission electron microscopy(TEM),and scanning electron microscopy(SEM) characterization techniques were employed to analyze the mechanism of TrGO's influence on PP's creep behavior. It was observed that when TrGO content exceeded 1.0 wt%, an effective particle network structure formed within the PP matrix. This homogeneously dispersed TrGO-formed particle network structure restricted the migration and rearrangement of PP molecular chains, enabling prolonged stress resistance without structural failure. By combining the time-strain superposition method with the critical failure strain as a criterion, generalized creep compliance curves for PP and its composites were established, facilitating the prediction of material creep failure lifetimes, with a strong agreement between experimental and predicted lifetime values. This research proposes a novel strategy aimed at developing polypropylene materials and products with enhanced long-term stability and durability, thus extending service life, reducing failure risk, and broadening their potential across various application domains.

关键词： Thermally reduced graphene oxide Polypropylene Creep failure and lifetime prediction

Scattering of Oblique Water Waves by Two Unequal Surface-Piercing Vertical Thin Plates with Stepped Bottom Topography

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China Ocean Engineering 2018年第5期32卷 524-535页

作者： WANG Li-xian DENG zheng-zhi WANG Chen WANG Peng Key Laboratory of High Performance Ship Technology (Wuhan University of Technology) Ministry of Education Departments of Naval Architecture Ocean and Structural EngineeringSchool of TransportationWuhan University of Technology Institute of Port Coastal and Offshore EngineeringOcean CollegeZhejiang University

Based on linear water-wave theory, this study investigated the scattering of oblique incident water waves by two unequal surface-piercing thin vertical rigid plates with stepped bottom topography. By using the matched eigenfunction expansion method and a least square approach, the analytical solutions are sought for the established boundary value problem. The effects of the incidence angle, location of step, depth ratio of deep to shallow waters,and column width between two plates, on the reflection coefficients, the horizontal wave forces acting on the two plates, and the mean surface elevation between the two plates, are numerically examined under a variety of wave conditions. The results show that the existence of the stepped bottom between two plates considerably impacts the hydrodynamic performances of the present system. It is found that the effect of stepped bottom on the reflection coefficient of the present two-plate structure is evident only with waves of the low dimensionless ***, the influence of the step location on the hydrodynamic performance of the present two-plate structure is slight if the step is placed in between the two plates.

关键词： stepped bottom topography two unequal thin vertical rigid plates oblique water waves reflection coefficient wave force

The HD-Zip transcription factor GhHB12 represses plant height by regulating the auxin signaling in cotton

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Journal of Integrative Agriculture 2023年第7期22卷 2015-2024页

作者： LIU Yan WANG Wei-ping ZHANG Lin ZHU long-fu ZHANG xian-long HE Xin College of Agronomy Hunan Agricultural UniversityChangsha 410128P.R.China National Key Laboratory of Crop Genetic Improvement Huazhong Agricultural UniversityWuhan 430070P.R.China

Upland cotton(Gossypium hirsutum L.)is the most important natural textile fiber crop *** height(PH)is a significant component of plant architecture,strongly influencing crop cultivation patterns,overall yield,and economic ***,cotton genes regulating plant height have not been fully ***,an HD-Zip gene(GhHB12)was isolated and characterized in cotton,which regulates the abiotic and biotic stress responses and the growth and development *** this study,we showed that GhHB12 was induced by ***,overexpression of GhHB12 induces the expression of HY5,ATH1,and HAT4,represses the spatial-temporal distribution,polar transport,and signaling of auxin,alters the expression of genes involved in cell wall expansion,and restrains the plant height in *** results suggest a role of GhHB12 in regulating cotton plant height,which could be achieved by affecting the auxin signaling and cell wall expansion.

关键词： cotton GhHB12 plant height auxin cell wall HD-Zip