检索结果-南通市图书馆

Modeling and simulation for a new virtual-clock-based collision resolution algorithm

在线全文

学校读者我要写书评

暂无评论

High Technology Letters 2006年第2期12卷 124-128页

作者：尹汝泼 Cai yunze he xing Zhang weidong Xu xiaoming Department of Automation Shanghai Jiaotong University Shanghai 200030 P.R. China

Virtual time Ethemet is a multiple access protocol proposed to provide FCFS transmission service over the predominant Ethemet bus. It incorporates a novel message-rescheduling algorithm based on the virtual clock mechanism. By manipulating virtual clocks back up over a common virtual time axis and performing timely collision resolution, the algorithm guarantees the system＇s queuing strictness. The protocol is particularly modeled as a finite state machine and implemented using OPNET tools. Simulation studies prove its correctness and effectiveness.

关键词： collision resolution virtual clock Ethernet OPNET

Hierarchical CuCo_2O_4@nickel-cobalt hydroxides core/shell nanoarchitectures for high-performance hybrid supercapacitors

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Science Bulletin 2017年第16期62卷 1122-1131页

作者： Chenggang Wang Kai Guo weidong he Xiaolong Deng Peiyu Hou Fuwei Zhuge Xijin Xu Tianyou Zhai School of Physics and Technology University of Jinan State Key Laboratory of Material Processing and Die & Mould Technology School of Materials Science and EngineeringHuazhong University of Science and Technology(HUST)

Ni0.5Co0.5（OH）2 nanosheets coated CuCo2O4 nanoneedles arrays were successfully designed and synthe- sized on carbon fabric. The core/shell nanoarchitectures directly served as the binder-free electrode with a superior capacity of 295.6 mAh g-1 at 1 Ag-1, which still maintained 220 mAh g-1 even at the high current density of 40 A g-l, manifesting their enormous potential in hybrid supercapacitor devices. The asassembled CuCo2O4@Ni0.5Co0.5（OH）2]]AC hybrid supercapacitor device exhibited favorable properties with the specific capacitance as high as 90 F g 1 at 1 A g-1 and the high energy density of 32 Wh kg 1 at the power density of 800 Wkg-1. Furthermore, the as-assembled device also delivered excellent cycling performance （retaining 91.9% of the initial capacitance after 12,000 cycles at 8 A g 1） and robust mechanical stability and flexibility, implying the huge potential of present hierarchical electrodes in energy storage devices.

关键词： Spinel CuCo2O4 Nickel-cobalt hydroxides Hybrid supercapacitors Hydrothermal method Electrodeposition

Electrolyte Engineering for High-Voltage Lithium Metal Batteries

在线全文

学校读者我要写书评

暂无评论

Research 2022年第4期2022卷 781-832页

作者： Liweidong Shijie Zhong Botao Yuan Yuanpeng Ji Jipeng Liu Yuanpeng Liu Chunhui Yang Jiecai Han weidong he MIIT Key Laboratory of Critical Materials Technology for New Energy Conversion and Storage School of Chemistry and Chemical EngineeringHarbin Institute of TechnologyHarbin 150080China National Key Laboratory of Science and Technology on Advanced Composites in Special Environments and Center for Composite Materials and Structures Harbin Institute of TechnologyHarbin 150080China State Key Laboratory of Urban Water Resource and Environment Harbin Institute of TechnologyHarbin 150080China Chongqing Research Institute Harbin Institute of TechnologyChongqing 401151China School of Mechanical Engineering Chengdu UniversityChengdu610106China

High-voltage lithium metal batteries(HVLMBs)have been arguably regarded as the most prospective solution to ultrahigh-density energy storage devices beyond the reach of current ***,the only component inside the HVLMBs in contact with both aggressive cathode and Li anode,is expected to maintain stable electrode/electrolyte interfaces(EEIs)and facilitate reversible Li+***,traditional electrolytes with narrow electrochemical windows fail to compromise the catalysis of high-voltage cathodes and infamous reactivity of the Li metal anode,which serves as a major contributor to detrimental electrochemical performance fading and thus impedes their practical *** stable electrolytes is vital for the further development of ***,optimization principles,design strategies,and future perspectives for the electrolytes of the HVLMBs have not been summarized in *** review first gives a systematical overview of recent progress in the improvement of traditional electrolytes and the design of novel electrolytes for the *** strategies of conventional electrolyte modification,including high concentration electrolytes and CEI and SEI formation with additives,are *** electrolytes including fluorinated,ionic-liquid,sulfone,nitrile,and solid-state electrolytes are also *** addition,theoretical studies and advanced characterization methods based on the electrolytes of the HVLMBs are probed to study the internal mechanism for ultrahigh stability at an extreme *** also foresees future research directions and perspectives for further development of electrolytes in the HVLMBs.

关键词： electrolyte maintain summarized

Modification strategies for non-aqueous, highly proton-conductive benzimidazole-based high-temperature proton exchange membranes

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2024年第4期35卷 43-51页

作者： Yunfa Dong Shijie Zhong Yuhui he Zhezhi Liu Shengyu Zhou Qun Li Yashuai Pang Haodong Xie Yuanpeng Ji Yuanpeng Liu Jiecai Han weidong he National Key Laboratory of Science and Technology on Advanced Composites in Special Environments and Center for Composite Materials and StructuresHarbin Institute of TechnologyHarbin 150080China School of Petroleum Engineering Chongqing University of Science and TechnologyChongqing 401331China School of Physics University of Electronic Science and Technology of ChinaChengdu 610054China MIIT Key Laboratory of Critical Materials Technology for New Energy Conversion and Storage School of Chemistry and Chemical EngineeringHarbin Institute of TechnologyHarbin 150001China Chongqing Research Institute Harbin Institute of TechnologyChongqing 401151China School of Mechanical Engineering Chengdu UniversityChengdu 610106China

High-temperature proton exchange membranes(HT-PEMs) possess excellent thermal and outstanding electrochemical stability, providing an avenue to realize high-temperature proton exchange membranes fuel cells(HT-PEMFCs) with both superior power density and long-term durability. Unfortunately, polybenzimidazole(PBI), a typical material for conventional HT-PEMs, fails to compromise the high nonaqueous proton conductivity and high mechanical properties, thus hindering their practical *** efficient nonaqueous proton conduction is crucial for HT-PEMFC, and many insightful research works have been done in this area. However, there still lacks a report that integrates the host-guest interactions of phosphoric acid doping and the structural stability of polymers to systematically illustrate modification strategies. here, we summarize recent advancements in enhancing the nonaqueous proton conduction of HT-PEMs. Various polymer structure modification strategies, including main chain and side group modification, cross-linking, blocking, and branching, are reviewed. Composite approaches of polymer, including compounding with organic porous polymers, filling the inorganic components and modifying with ionic liquids, etc., are also covered in this work. These strategies endow the HT-PEMs with more free volume, nanophase-separated structure, and multi-stage proton transfer channels, which can facilitate the proton transportation and improve their performance. Finally, current challenges and future directions for further enhancements are also outlined.

关键词： Benzimidazole Nonaqueous proton conduction Free volume Nanophase-separated structure Structure modification

MoP QDs@graphene as highly efficient electrocatalyst for polysulfide conversion in Li-S batteries

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2021年第31期90卷 37-44页

作者： Bo Yu Fei Ma Dongjiang Chen Katam Srinivas Xiaojuan Zhang Xinqiang Wang Bin Wang Wanli Zhang Zegao Wang weidong he Yuanfu Chen School of Electronic Science and Engineering and State Key Laboratory of Electronic Thin Films and Integrated DevicesUniversity of Electronic Science and Technology of ChinaChengdu 610054PR China School of Physics University of Electronic Science and Technology of ChinaChengdu 611731PR China School of Science and Institute of Oxygen SupplyTibet UniversityLhasa 850000PR China College of Materials Science and Engineering Sichuan UniversityChengdu 610065PR China

The shuttle effect of lithium polysulfides(LiPSs)and sluggish redox conversion significantly hinder practical implementation of lithium-sulfur batteries(LSBs).To overcome these issues,herein,we present MoP quantum dots anchored N,P-doped graphene(MPQ@G)as a multifunctional LSB *** N,P-doped graphene layers serve as a conductive skeleton to support the MoP QDs which can accelerate the electron transfer,physically hinder the polysulfide migration and thus enhance the electrochemical *** importantly,as a polar and conductive catalyst,MoP QDs provide catalytically active sites for the conversion of *** a result,the LSBs with MPQ@G/S cathodes deliver an elevated initial capacity of 1220.2 mAh g~(-1)at 0.2 C and remain 98.9%after rate cycles,signifying its exceptional cycling ***,it displays a large capacity of 681.2 mAh g~(-1)even at a high rate of 1 *** Li-S pouch cell also presents high specific capacities and preeminent cycling stabilities,confirming its great potential for high-rate *** functional theory calculations demonstrate the improved absorptivity and redox conversion reversibility of *** work provides an efficient strategy to improve composite with highly adsorptive and catalytic properties for high-performance Li-S batteries.

关键词： MoP quantum dots Graphene Electrocatalyst Shuttle effect Li-S batteries

A Single-Layer Piezoelectric Composite Separator for Durable Operation of Li Metal Anode at High Rates

在线全文

学校读者我要写书评

暂无评论

Energy & Environmental Materials 2024年第1期7卷 265-274页

作者： Yuanpeng Ji Botao Yuan Jiawei Zhang Zhezhi Liu Shijie Zhong Jipeng Liu Yuanpeng Liu Mengqiu Yang Changguo Wang Chunhui Yang Jiecai Han weidong he National Key Laboratory of Science and Technology on Advanced Composites in Special Environments and Center for Composite Materials and StructuresHarbin Institute of TechnologyHarbin 150080China MIIT Key Laboratory of Critical Materials Technology for New Energy Conversion and Storage School of Chemistry and Chemical EngineeringHarbin Institute of TechnologyHarbin 150080China School of Petroleum Engineering Chongqing University of Science and TechnologyChongqing 401331China State Key Laboratory of Urban Water Resource and Environment Harbin Institute of TechnologyHarbin 150080China Chongqing Research Institute Harbin Institute of TechnologyChongqing 401151China School of Mechanical Engineering Chengdu UniversityChengdu 610106China

Piezoelectric ceramic and polymeric separators have been proposed to effectively regulate Li deposition and suppress dendrite growth,but such separators still fail to satisfactorily support durable operation of lithium metal batteries owing to the fragile ceramic layer or low-piezoelectricity polymer as ***,by combining PVDF-HFP and ferroelectric BaTiO_(3),we develop a homogeneous,single-layer composite separator with strong piezoelectric effects to inhibit dendrite growth while maintaining high mechanical *** squeezed by local protrusion,the polarized PVDF-HFP/BaTiO_(3)composite separator generates a local voltage to suppress the local-intensified electric field and further deconcentrate regional lithium-ion flux to retard lithium deposition on the protrusion,hence enabling a smoother and more compact lithium deposition morphology than the unpoled composite separator and the pure PVDF-HFP separator,especially at high ***,the homogeneous incorporation of BaTiO_(3)highly improves the piezoelectric performances of the separator with residual polarization of 0.086 pC cm^(-2)after polarization treatment,four times that of the pure PVDF-HFP separator,and simultaneously increases the transference number of lithium-ion from 0.45 to *** from the prominent piezoelectric mechanism,the polarized PVDF-HFP/BaTiO_(3)composite separator enables stable cyclic performances of Li||LiFePO_(4)cells for 400 cycles at 2 C(1 C=170 mA g^(-1))with a capacity retention above 99%,and for 600 cycles at 5 C with a capacity retention over 85%.

关键词： composite separator Li metal anodes piezoelectric materials PVDF-HFP uniform Li deposition

Optimization of Numerical Control Program and Machining Simulation Based on VERICUT

在线全文

学校读者我要写书评

暂无评论

Journal of Shanghai Jiaotong university(Science) 2019年第6期24卷 763-768页

作者： ZHOU Feng ZHANG Zixu WU Chang TIAN Xin LIU Haotian he weidong School of Mechanical Engineering Dalian Jiaotong UniversityDalian 116028LiaoningChina

In the machining process of large-scale complex curved surface,workers will encounter problems such as empty stroke of tool,collision interference,and overcut or undercut of the *** paper presents a method for generating the optimized tool path,compiling and checking the numerical control(NC)*** the bogie frame as an example,the tool paths of all machining surface are optimized by the dynamic programming algorithm,Creo software is utilized to compile the optimized computerized numerical control(CNC)machining program,and VERICUT software is employed to simulate the machining process,optimize the amount of cutting and inspect the machining *** method saves the machining time,guarantees the correctness of NC program,and the overall machining efficiency is *** method lays a good theoretical and practical foundation for integration of the similar platform.

关键词： numerical control program bogie frame dynamic programming algorithm machining simulation VERICUT

Printable Aligned Single-Walled Carbon Nanotube Film with Outstanding Thermal Conductivity and Electromagnetic Interference Shielding Performance

在线全文

学校读者我要写书评

暂无评论

Nano-Micro Letters 2022年第11期14卷 143-156页

作者： Zhihui Zeng Gang Wang Brendan F.Wolan Na Wu Changxian Wang Shanyu Zhao Shengying Yue Bin Li weidong he Jiurong Liu Joseph W.Lyding Key Laboratory for Liquid-Solid Structural Evolution and Processing of Materials Ministry of EducationSchool of Materials Science and EngineeringShandong UniversityShandongJinan 250061People’s Republic of China Department of Electrical and Computer Engineering Beckman Institute for Advanced Science and TechnologyUniversity of Illinois at Urbana-ChampaignUrbanaIL 61801USA Department of Chemistry Swiss Federal Institute of Technology in Zurich(ETH Zürich)8092 ZurichSwitzerland School of Materials Science and Engineering Nanyang Technological University50 Nanyang AvenueSingapore 639798Singapore Empa Swiss Federal Laboratories for Materials Science and TechnologyÜberland Strasse 1298600 DübendorfSwitzerland Institute for Advanced Technology Shandong UniversityJinan 250061People’s Republic of China

Ultrathin,lightweight,and flexible aligned single-walled carbon nanotube(SWCNT)films are fabricated by a facile,environmentally friendly,and scalable printing *** aligned pattern and outstanding intrinsic properties render“metal-like”thermal conductivity of the SWCNT films,as well as excellent mechanical strength,flexibility,and ***,the aligned cellular microstructure promotes the electromagnetic interference(EMI)shielding ability of the SWCNTs,leading to excellent shielding effectiveness(SE)of~39 to 90 dB despite a density of only~0.6 g cm^(−3) at thicknesses of merely 1.5-24μm,*** ultrahigh thickness-specific SE of 25693 dB mm^(−1) and an unprecedented normalized specific SE of 428222 dB cm^(2)g^(−1) are accomplished by the freestanding SWCNT films,significantly surpassing previously reported shielding *** addition to an EMI SE greater than 54 dB in an ultra-broadband frequency range of around 400 GHz,the films demonstrate excellent EMI shielding stability and reliability when subjected to mechanical deformation,chemical(acid/alkali/organic solvent)corrosion,and high-/low-temperature *** novel printed SWCNT films offer significant potential for practical applications in the aerospace,defense,precision components,and smart wearable electronics industries.

关键词： Aligned film Single-walled carbon nanotube Lightweight Flexible Thermal conductivity Electromagnetic interference shielding

Mass transfer in ion-conducting crystals for fuel cell and Li ion battery applications

在线全文

学校读者我要写书评

暂无评论

Mass transfer in ion-conducting crystals for fuel cell and L...