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A Fast and Room-temperature Self-healing Thermal Conductive Polymer Composite

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Chinese Journal of Polymer Science 2021年第10期39卷 1328-1336,I0008页

作者： De-Wei Yue hong-Qin Wang Han-Qing Tao peng Zheng cheng-Hui Li Jing-Lin Zuo State Key Laboratory of Coordination Chemistry School of Chemistry and Chemical EngineeringNational Laboratory of MicrostructuresCollaborative Innovation Center of Advanced MicrostructuresNanjing UniversityNanjing 210023China

Thermal conducting materials may be damaged during long-term use,resulting in the increase of thermal resistance and therefore inefficient heat *** introduction of self-healing ability may solve this problem,but the realization of fast and room-temperature self-healing in thermal conducting composites is quite ***,we choose a flexible poly(dimethylsiloxane)polymer material(PDMS-COOH)as the matrix and graphene nanosheets as the thermal conductive filler to prepare a new kind of thermal conductive polymer composite(PDMS-COOH-CG)that can quickly self-heal at room *** thermal conductivity of PDMS-COOH-CG10 with 10%of graphene content is 0.48 W·m^(-1)·K^(-1),which is 16 times that of PDMS-COOH(0.03 W·m^(-1)·K^(-1)).At room temperature,self-healing efficiency of PDMS-COOH-CG10 based on tensile strength can be 53.8%for 30 s and 84.6%for 24 *** infrared thermal imaging dipicted that after 2 min of self-healing at room temperature,the thermal conduction temperature near the damage was basically restored to the level of the pristine sample.

关键词： Self-healing Thermal conductive Infrared thermal imaging

Role of the dressed and bound states on below-threshold harmonic generation of He atom

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Chinese Physics B 2019年第10期28卷 192-197页

作者： Jian-Wei Zhou Zhi-hong Jiao peng-cheng Li Xiao-Xin Zhou Key Laboratory of Atomic and Molecular Physics and Functional Materials of Gansu Province College of Physics and Electronic EngineeringNorthwest Normal University

High-order harmonic generation below ionization threshold of He atom in the laser field is investigated by solving the three-dimensional time-dependent Schrodinger equation. An angular momentum-dependent model potential of He atom was used for getting the accurate energy levels of singlet states. The satellite-peak structures of the below-threshold harmonic generation(BTHG) of He are observed. We analyze the emission properties of the BTHG by employing a synchrosqueezing transform technique. We find that the satellite-peak structures have two types related to two kinds of transitions. One is the transition of the dressed states of the excited states, the other is the transition between the excited states and the ground state in the field-free case. Furthermore, our results show that the maximum Stark shift of the 2 p state is about 0.9 Up(penderomotive energy), and that of the 4 p state is about 1.0 Up. It indicates that the energy difference between some satellite-and main-peaks of the BTHG can be used to measure the maximum Stark shift of the excited states of He atom in the laser field.

关键词： harmonic generation below threshould ionization dress state Stark shift

Spiral Vector Modeling of Brushless Doubly-fed Induction Machines with Short-circuited Rotor Windings

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Chinese Journal of Electrical Engineering 2021年第3期7卷 29-41页

作者： peng Han Ming cheng Zhiwei Zhang peng peng Ansys Inc.San JoseCA 95134USA School of Electrical Engineering Southeast UniversityNanjing 210096China Department of ECE The Ohio State UniversityColumbusOH 43210USA Milwaukee Electric Tool Corporation MilwaukeeWI 53005USA

A unified spiral vector model is presented that can be used to assist the finite element method-based performance analysis of brushless doubly-fed induction machines with various short-circuited rotor ***,magnet-free brushless doubly-fed induction machines working in doubly-fed or singly-fed synchronous mode are investigated.A dynamic model in spiral vector notation is developed,based on which the torque-angle and power-angle characteristics are *** is shown that the investigated brushless machines are equivalent to a traditional non-salient-pole synchronous machine with *** introducing a conversion factor,they can also be analyzed with methods similar to the conventional phasor theory.A comparison is made between the brushless doubly-fed induction machine and non-salient-pole wound-field synchronous machine with brushes,revealing that the performance of the brushless machine degrades faster when the laminated core is saturated.A scaled-down prototype is tested to validate the effectiveness of the theoretical analysis.

关键词： AC machine brushless machine modeling performance evaluation synchronous machine

Using Multi-agent System for Residential Expansion Models——A Case Study of hongshan District,Wuhan City

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Chinese Geographical Science 2007年第3期17卷 210-215页

作者： peng Chong cheng Jianquan Department of Urban and Resources Sciences Nanjing UniversityNanjing210093China Department of Environmental&Geographical Sciences Manchester Metropolitan UniversityM15GDUK

Residential expansion is gaining more and more attention from government authorities and urban ***,most of the current urban models focus heavily on presenting economic,political and ecological objectives of urban development,while seldom taking the effects of human behavior into ***-agent systems for land use/cover change(MAS/LUCC),which mainly concern the behavioral effects of stakeholders on the processes of land use/cover change,are promising to fill the *** article,based on the concepts of MAS/LUCC model,con-structs a multi-agent system for residential expansion model(MAS/RE)through the analysis of the behavior of gov-ernment authorities and *** model takes complex human actions into account,namely urban master plan-ning,planning review and approval,policies of traffic,economy and environment,location and allocation choices of the households and their *** hongshan District of Wuhan City,Hubei Province as an illustration,the model is implemented on Arc/info platform to simulate residential expansion between 1996 and *** study result shows that the model is suitable for understanding the process of residential expansion with the effects of human actions,and is especially effective for its capacity in presenting spatio-temporal and behavioral ***,the model can be a reference for policy-making for government authorities and urban planners.

关键词： residential expansion MAS/RE model GIS location choice

Ion-beam-assisted characterization of quinoline-insoluble particles in nuclear graphite

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Nuclear Science and Techniques 2020年第10期31卷 23-32页

作者： Qing Huang Xin-Qing Han peng Liu Jian-Jian Li Guan-hong Lei cheng Li Shanghai Institute of Applied Physics Chinese Academy of SciencesShanghai 201800China School of Physics State Key Laboratory of Crystal MaterialsKey Laboratory of Particle Physics and Particle Irradiation(MOE)Shandong UniversityJinan 250100China

The irradiation behavior of graphite is essential for its applications in the nuclear ***,the behavioral differences of graphite remain obscure because of the very limited comprehension of its microstructural *** typical structure,the quinoline-insoluble(QI)particle,was investigated using IG-110 and NBG-18 *** irradiation,the QI particles on the polished surface were proven to become hillocks,which were easily identifiable via scanning electron microscopy(SEM).Thus,a method that combined ion irradiation and SEM characterization was proposed to study the distribution and concentration of QI particles in *** irradiation,the QI particles were found to evolve into densified spheres,which were weakly bonded with the surrounding graphite structures,thereby indicating that the densification of QI particles did not evidently contribute to graphite dimensional shrinkage.A much higher concentration of QI particles in NBG-18 than IG-110,which was suggested to be responsible for the smaller maximum dimensional shrinkage of former over the latter during irradiation,was characterized.

关键词： Heavy ion irradiation Nuclear graphite Quinoline insoluble Microstructure

Frame-level traffic splitting for link aggregation in data center networks

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The Journal of China Universities of Posts and Telecommunications 2013年第2期20卷 66-72页

作者： ZHANG peng WANG hong-bo cheng Shi-duan LI Yang-yang DONG Jian-kang State Key Laboratory of Networking and Switching Technology Beijing University of Posts and Telecommunications

Ethernet link aggregation, which provides an easy and cost-effective way to increase both bandwidth and link availability between a pair of devices, is well suited for data center networks. However, all the traffic splitting algorithms used in existing Ethernet link aggregation are flow-level which do not work well owing to the traffic characteristics of data centers. Though frame-level traffic splitting can achieve optimal load balance and the maximum benefits from aggregated capacity, it is generally deprecated in most cases because of frame disordering which can disrupt the operation of many Internet protocols, most notably transmission control protocol （TCP）. To address this issue, we first investigate the causes of frame disordering in link aggregation and find that all of them either are no longer true or can be prevented in data centers. Then we present a byte-counter frame-level traffic splitting algorithm which achieves optimal performance while causes no frame disordering. The only requirement is that frames in a flow are the same size which can be easily met in data centers. Simulation results show that the proposed frame-level traffic splitting method could achieve higher throughput and optimal load balance. The average completion time of different sized flows is reduced by 24% on average and by up to 46%.

关键词： data center networks Ethernet link aggregation frame-level traffic splitting

Sealing Effect of KAl(SO_(4))_(2)Solution on the Corrosion Resistance of Anodized Aluminum Alloy

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Journal of Wuhan University of Technology(Materials Science) 2022年第1期37卷 104-109页

作者： cheng Jie DONG peng School of Electrical Engineering Nanjing Vocational University of Industry TechnologyNanjing 210023China Crystal Physics Research Center Nanjing University of Posts and TelecommunicationsNanjing 210023China College of Electronic and Optical Engineering&College of Microelectronics Nanjing University of Posts and TelecommunicationsNanjing 210023China

The 2024 anodized aluminum alloy film was sealed by KAl(SO_(4))_(2)solution and the effect of sealing on corrosion resistance was investigated by means of potentiodynamic polarization curves,electrochemical impedance spectroscopy,and X-ray photoelectron *** experimental results show that the optimal parameters for KAl(SO_(4))_(2)sealing are 35℃,with the pH value of 8,the concentration of 8 g/L,and the sealing time of 3 *** corrosion resistance of the KAl(SO_(4))_(2)sealed sample can be significantly improved than that of unsealed one,and is obviously superior to that of the conventional hydrothermal sealed ***,X-ray photoelectron spectroscopy demonstrates that more Al(OH)_(3)will be formed in the process of KAl(SO_(4))_(2)sealing,which will shrink the diameter of the microporous and therefore results in the excellent corrosion resistance.

关键词： aluminum alloy anodic oxidation KAl(SO_(4))_(2)solution sealing corrosion resistance

DATCP:deadline-aware TCP for the commoditized data centers

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The Journal of China Universities of Posts and Telecommunications 2012年第6期19卷 52-62页

作者： ZHANG peng WANG hong-bo LI Yang-yang DONG Jian-kang cheng Shi-duan State Key Laboratory of Networking and Switching Technology Beijing University of Posts and Telecommunications

Many flows in data centers have deadlines and missing deadlines would hurt application performance such as affecting response quality in Web applications or delaying computing jobs in MapReduce-like systems. However, transmission control protocol （TCP） which is widely used in data centers now cannot provide deadline-aware transmission service. Service differentiation only distinguishes flows with different priority but is unable to guarantee completion time. In this paper, we propose a new protocol named deadline-aware TCP （DATCP） to provide deadline-aware transmission service for the commoditized data centers, which can be used as a flexible method for flow scheduling. DATCP combines flow urgency and importance to calculate precedence. Flow urgency is dynamically adjusted according to the gap between desired rate and actual throughput. Setting importance can avoid starving the important but no-urgent flows. Furthermore, a flow quenching method is presented which allows as many high precedence flows as possible to meet deadlines under heavy network load. By extensive simulations, the performance of DATCP was evaluated. Simulation results show that DATCP can make flows meet deadlines effectively.

关键词： data center networks (DCN) deadline-aware transmission service TCP flow scheduling

Thermal hydraulic characteristics of helical coil once-through steam generator under ocean conditions

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Nuclear Science and Techniques 2022年第10期33卷 139-150页

作者： Tian-Ze Bai Chang-hong peng School of Nuclear Science and Technology University of Science and Technology of ChinaNo.96Jinzhai RoadBaohe DistrictHefei 230026China

Owing to its advantages of high heat transfer efficiency and compactness, the helical coil once-through steam generator(HCOTSG) can be used in floating nuclear power plants and has been widely used in the design of small modular reactors. The helical tubular geometric structure of the HCOTSG allows heat transfer and local flow changes to occur under complex ocean conditions. In this study, theoretical models of ocean conditions are added to the RELAP5/MOD3.3 code and verified. Using the modified RELAP5 code, the thermal–hydraulic characteristics of the HCOTSG under ocean conditions are simulated. The results show that under rolling conditions, the flow oscillation amplitudes of the single liquid-phase, twophase flow, and single gas-phase regions are different. A circular change in the horizontal position of the helical tube causes the fluctuation of the parameters to change periodically. A phase difference of approximately 3.9 s at a flow rate of 23 kg/s is observed in the flow fluctuation along the axial direction. The driving force, period, and amplitude of rolling significantly affect the flow fluctuation in the HCOTSG. In natural circulation, the flow in the HCOTSG is complex, and the primary-side flow fluctuation can reduce the trough of the flow oscillation at the helical tube by approximately 24.3%.

关键词： RELAP5 HCOTSG Ocean conditions Thermal–hydraulic analysis Flow oscillation