检索结果-南通市图书馆

Complex Dynamical Behaviors in a Dual Channel Supply Chain Model with Retailer's Service Input

Journal of Systems Science & Complexity 2023年第3期36卷 1144-1168页

作者： ZHANG Yapeng ZHOU Wei School of Mathematics and Physics Lanzhou Jiaotong UniversityLanzhou 730070China School of Traffic and Transportation Lanzhou Jiaotong UniversityLanzhou 730070China Key Laboratory of Railway Industry of Plateau Railway Transportation Intelligent Management and Control Lanzhou 730070China

Based on bounded rationality,this paper established a price game model of dual channel supply chain composed of manufacturers and retailers.According to the eigenvalue of Jacobi matrix and Jury criterion,the stability of the equilibrium point is analyzed,and then the dynamic evolution process under the parameters of price adjustment speed and retailer's service input is studied through stability region,bifurcation diagram,maximum Lyapunov exponent diagram and attraction basin.The results show that the system enters chaos through flip and Neimark-Sacker bifurcation,and increase of price adjustment speed and service input value will make the system produce more dynamic behavior.In addition,it can be found that the impact of service input value on itself is much greater than that on manufacturers.Secondly,when adjustment speed is selected as bifurcation parameter,the change curve of sales price is inconsistent,in which the change of retailers mainly remains in periodic state,while manufacturers will gradually enter chaos.Finally,studies the evolution of attraction basin in which three kinds of attractors coexist.In particular,coexistence of boundary attractors and internal attractors increases the complexity of system.Therefore,enterprises need to carefully adjust parameters of the game model to control the stability of system and maintain the long-term stability of market competition.

关键词： Bifurcation analysis boundary equilibrium coexistence of attractors flip bifurcation global bifurcation

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Deep Reinforcement Learning-Based Resource Allocation for UAV-Enabled Federated Edge Learning

引用

Journal of Communications and Information Networks 2023年第1期8卷 1-12页

作者： Tianze Liu Tiankui zhang Jonathan Loo yapeng Wang School of Information and Communication Engineering Beijing University of Posts and TelecommunicationsBeijing 100876China School of Computing and Engineering University of West LondonLondon W55RFUK Faculty of Applied Sciences Macao Polytechnic UniversityMacao 999078China

The resource allocation of the federated learning(FL)for unmanned aerial vehicle(UAV)swarm systems are investigated.The UAV swarms based on FL realize the artificial intelligence(AI)applications by means of distributed training on the basis of ensuring the security of private data.However,the direct application of the FL in UAV swarms will incur high overhead.Therefore,in this article,we consider the resource allocation problem in FL for UAV swarms.To avoid the high communication overhead between UAVs and the central server,we proposed an FL framework for UAV swarms based on mobile edge computing(MEC)in which model aggregation is migrated to edge servers.In the proposed framework,the total cost of the FL is defined as the weighted sum of the total delay of UAV swarms to complete the FL and system energy consumption.In order to minimize the total cost of FL,we propose a resource allocation algorithm for joint optimization of computing resources and multi-UAV association based on deep reinforcement learning(DRL).The simulation result shows that:(1)compared with the benchmark algorithm,the proposed algorithm can effectively reduce the total cost of FL;(2)the proposed algorithm can realize the trade-off between task completion delay and system energy consumption through weight changes.

关键词： DRL FL MEC UAV

来源：

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

Enhanced Harris Hawks Optimization Integrated with Coot Bird Optimization for Solving Continuous Numerical Optimization Problems

引用

Computer Modeling in Engineering & Sciences 2023年第11期137卷 1635-1675页

作者： Hao Cui Yanling Guo Yaning Xiao Yangwei Wang Jian Li yapeng zhang Haoyu zhang College of Mechanical and Electrical Engineering Northeast Forestry UniversityHarbin150040China

Harris Hawks Optimization(HHO)is a novel meta-heuristic algorithm that imitates the predation characteristics of Harris Hawk and combines Lévy flight to solve complex multidimensional problems.Nevertheless,the basic HHO algorithm still has certain limitations,including the tendency to fall into the local optima and poor convergence accuracy.Coot Bird Optimization(CBO)is another new swarm-based optimization algorithm.CBO originates from the regular and irregular motion of a bird called Coot on the water’s surface.Although the framework of CBO is slightly complicated,it has outstanding exploration potential and excellent capability to avoid falling into local optimal solutions.This paper proposes a novel enhanced hybrid algorithm based on the basic HHO and CBO named Enhanced Harris Hawks Optimization Integrated with Coot Bird Optimization(EHHOCBO).EHHOCBO can provide higher-quality solutions for numerical optimization problems.It first embeds the leadership mechanism of CBO into the population initialization process of HHO.This way can take full advantage of the valuable solution information to provide a good foundation for the global search of the hybrid algorithm.Secondly,the Ensemble Mutation Strategy(EMS)is introduced to generate the mutant candidate positions for consideration,further improving the hybrid algorithm’s exploration trend and population diversity.To further reduce the likelihood of falling into the local optima and speed up the convergence,Refracted Opposition-Based Learning(ROBL)is adopted to update the current optimal solution in the swarm.Using 23 classical benchmark functions and the IEEE CEC2017 test suite,the performance of the proposed EHHOCBO is comprehensively evaluated and compared with eight other basic meta-heuristic algorithms and six improved variants.Experimental results show that EHHOCBO can achieve better solution accuracy,faster convergence speed,and a more robust ability to jump out of local optima than other advanced optimizers in most test cases.Finally,EHHOCBOis applied to ad

关键词： Harris hawks optimization coot bird optimization hybrid ensemblemutation strategy refracted opposition-based learning

来源：

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

城乡居民养老保险能提升政治参与吗?——基于政策反馈理论的实证研究

引用

广东社会科学 2024年第1期 179-196页

作者：张雨朱亚鹏中山大学政治与公共事务管理学院中山大学中国公共管理研究中心、政治与公共事务管理学院广州510275

中国已进入社会政策快速发展和完善的时代,然而学界对社会政策的发展和调整所带来的政治影响和后果关注较少。本研究运用政策反馈理论,以中国城乡居民养老保险政策为例,利用微观调查数据CSS2017分析了中国社会政策对大众政治的影响及其... 详细信息

中国已进入社会政策快速发展和完善的时代,然而学界对社会政策的发展和调整所带来的政治影响和后果关注较少。本研究运用政策反馈理论,以中国城乡居民养老保险政策为例,利用微观调查数据CSS2017分析了中国社会政策对大众政治的影响及其作用机制。研究发现:(1)城乡居民养老保险制度的发展提升了高制度化和低制度化政治参与,最终显著促进了公众的整体政治参与;(2)进一步分析发现,城乡居民养老保险金对高、低制度化政治参与的影响主要通过解释效应实现,资源效应不显著。即养老保险金的发放未对参保者的政治参与产生显著的影响,但是城乡居民养老保险能够通过增强居民的社会地位认知和对中央政府的信任等方式塑造参保者的认知和态度,进而促使高、低制度化政治参与水平增加。(3)城乡居民养老保险对非制度化政治参与无明显影响,资源效应和解释效应均不显著。本文的结果证实了基本养老保险制度在提升公民的政治参与水平方面发挥了积极作用,支撑了发展社会养老保险制度的合法性;同时也发现城乡居民养老保险所提供的资源及其产生的政治影响仍存在进一步发展的空间。

关键词：养老保险政治参与政策反馈理论资源效应解释效应

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

The First Global Map of Atmospheric Ammonia(NH_(3)) as Observed by the HIRAS/FY-3D Satellite

引用

Advances in Atmospheric Sciences 2024年第3期41卷 379-390页

作者： Minqiang ZHOU Zhili DENG Charles ROBERT Xingying zhang Lu zhang yapeng WANG Chengli QI Pucai WANG Martine De MAZIÈRE Institute of Atmospheric Physics Chinese Academy of SciencesBeijing 100029China Royal Belgian Institute for Space Aeronomy(BIRA-IASB) Brussels 1180Belgium National Satellite Meteorology Center China Meteorological AdministrationBeijing 100081China Department of Science&Technology and Climate Change China Meteorological AdministrationBeijing 100081China University of Chinese Academy of Sciences Beijing 100049China

Atmospheric ammonia(NH_(3)) is a chemically active trace gas that plays an important role in the atmospheric environment and climate change. Satellite remote sensing is a powerful technique to monitor NH_(3) concentration based on the absorption lines of NH_(3) in the thermal infrared region. In this study, we establish a retrieval algorithm to derive the NH_(3)column from the Hyperspectral Infrared Atmospheric Sounder(HIRAS) onboard the Chinese Feng Yun(FY)-3D satellite and present the first atmospheric NH_(3) column global map observed by the HIRAS instrument. The HIRAS observations can well capture NH_(3) hotspots around the world, e.g., India, West Africa, and East China, where large NH_(3) emissions exist. The HIRAS NH_(3) columns are also compared to the space-based Infrared Atmospheric Sounding Interferometer(IASI)measurements, and we find that the two instruments observe a consistent NH_(3) global distribution, with correlation coefficient(R) values of 0.28–0.73. Finally, some remaining issues about the HIRAS NH_(3) retrieval are discussed.

关键词： ammonia HIRAS/FY-3D satellite thermal-infrared observation remote sensing optimal estimation method

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Nitrogen doped porous carbon-based bifunctional oxygen electrocatalyst with controllable phosphorus content for zinc-air battery

引用

Nano Research 2023年第4期16卷 5887-5893页

作者： Shichang Cai Zihan Meng Gaojie Li Yu An yapeng Cheng Erjun Kan Bo Ouyang Haining zhang Haolin Tang School of Material Science and Engineering Henan University of TechnologyZhengzhou 450001China Foshan Xianhu Laboratory of the Advanced Energy Science and Technology Guangdong LaboratoryXianhu Hydrogen ValleyFoshan 528200China State Key Laboratory of Advanced Technology for Materials Synthesis and Processing Wuhan University of TechnologyWuhan 430070China Department of Applied Physics and Institution of Energy and Microstructure Nanjing University of Science and TechnologyNanjing 210094China

The controllable construction of non-noble metal based bifunctional catalysts with high activities towards oxygen reduction reaction(ORR)and oxygen evolution reaction(OER)is of great significance,but remains a challenge.Herein,we reported an effective method to synthesize cobalt-nitrogen doped mesoporous carbon-based bifunctional oxygen electrocatalyst with controllable phosphorus content(Co-N-P_(X)-MC,X=0.5,1.0,1.5,2.0).The mesoporous carbon substrate endowed the asprepared samples with more exposed active surface(236.50 m^(2)·g^(−1))and the most appropriate doping ratio of phosphorus had been investigated to be 1.5(Co-N-P1.5-MC).For ORR,Co-N-P1.5-MC exhibited excellent catalytic activity with more positive onset potential(1.01 V)and half-wave potential(0.84 V)than the other samples.For OER,Co-N-P1.5-MC also showed a low overpotential of 415 mV.Combining experimental results and density-functional theory(DFT)calculations,the outstanding bifunctional catalytic performance of Co-N-P1.5-MC was due to the synergistic cooperation between the P and N dopants,which could reduce the reaction barriers and was favorable for ORR and OER.Moreover,the Zn-air battery using Co-N-P1.5-MC as the cathode showed remarkable battery performance with high stability(could operate stably for over 160 h at 10 mA·cm^(−2))and maximum power density(119 mW·cm^(−2)),demonstrating its potential for practical applications.This work could provide significant enlightenment towards the design and construction of bifunctional oxygen electrocatalyst for next-generation electrochemical devices.

关键词： cobalt-nitrogen doped porous carbon phosphorus doping bifunctional electrocatalyst oxygen reduction reaction(ORR)and oxygen evolution reaction(OER) Zn-air battery

来源：

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

制造业转型的政策向度:基于国家治理的思考

引用

东南学术 2021年第6期 167-175页

作者：张亚鹏中国电子信息产业发展研究院

推动制造业发展是当前世界大国的基本经济议题。制造业不仅是实体经济的主体,也是现代产业体系的重要支撑,同时是推动构建新发展格局的“主战场”。制造业转型所涉及的产业结构、空间布局与发展模式等内容是理解与认识中国制造业的三个... 详细信息

推动制造业发展是当前世界大国的基本经济议题。制造业不仅是实体经济的主体,也是现代产业体系的重要支撑,同时是推动构建新发展格局的“主战场”。制造业转型所涉及的产业结构、空间布局与发展模式等内容是理解与认识中国制造业的三个重要方面。从国家治理角度看,中国制造业转型存在要素配置不合理、转型空间不均衡、转型模式待优化等结构性问题。针对当前中国制造业转型存在的问题,建议制定与实施差异化的政策类型与实践路径。

关键词：制造业转型政策嵌入国家治理政策设置

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Synthesis, Characterization, and Reactivity of Metalla- Chalcogenirenium Compounds

引用

Chinese Journal of Chemistry 2021年第6期39卷 1558-1564页

作者： Ming Luo yapeng Cai Xinlei Lin Lipeng Long Hong zhang Haiping Xia Shenzhen Grubbs Institute and Guangdong Provincial Key Laboratory of Catalysis Department of ChemistrySouthern University of Science and TechnologyShenzhenGuangdong 518055China College of Chemistry and Chemical Engineering Xiomen UniversityXiamenFujian 361005China

Chalcogenirenium cations,featuring an unsaturated three-membered organic ring,are limited but known to be synthesizable from alkynes with bulky electron-donating groups.Metalla-chalcogenirenium compounds have been synthesized as stable compounds through the reactions of a cyclic metal-carbyne complex-metallapentalyne with PhSCI,PhSeCI or PhTeCI.As a result of the high strain in the three-membered metallacycles,the metalla-chalcogenirenium cations react readily with the base or chloride ions.These reactions furnish a series of unprecedented chalcogenirenium cations with intact M=C bonds.The intrinsic stabilization effect of aromaticity is further elucidated by density functional calculations.

关键词： Metalla-chalcogenirenium Density functional calculations Metallacycles P-block cations Aromaticity

来源：

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

A high-accuracy DCO with hybrid architecture

引用

Journal of Semiconductors 2017年第7期38卷 111-116页

作者： yapeng Sun Huidong Zhao Shushan Qiao Yong Hei Fuhai zhang Collage of Electronic Information and Optical Engineering Nankai University Institute of Microelectronics Chinese Academy of Sciences

In this paper, a novel hybrid digital-controlled oscillator（DCO） is proposed, which is used to improve the accuracy of the all-digital clock generator without reference source. The DCO with hybrid architecture consists of two parts： DCO_high and DCO_low. The DCO_high decides the coarse output frequency of DCO, and adopts the cascade structure to decrease the area. The DCO_low adopts the chain structure with three-state buffer, and decides the fine output frequency of DCO. Compared with traditional cascade DCO, the proposed hybrid DCO features higher precision with less inherent delay. Therefore the clock generator can tolerate process, voltage and temperature（PVT） variation and meet the needs of different conditions. The DCO is designed in SMIC 180 nm CMOS process with 0.021 mm^2 chip area. The output frequency is adjusted from 15–120 MHz. The frequency error is less than 0.83% at 25 MHz with 1.6–1.8 V supply voltage and 0–80℃ temperature variations in TT, FF,SS corners.

关键词： high accuracy DCO all-digital PVT variations

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Enhanced tribological properties of aligned graphene-epoxy composites

引用

Friction 2022年第6期10卷 854-865页

作者： Yuefeng DU Zhenyu zhang Dong WANG Lezhen zhang Junfeng CUI yapeng CHEN Mingliang WU Ruiyang KANG Yunxiang LU Jinhong YU Nan JIANG Key Laboratory for Precision and Non-Traditional Machining Technology of Ministry of Education Dalian University of TechnologyDalian 116024China Beijing Spacecrafts Manufacturing Factory Co. Ltd.China Academy of Space TechnologyBeijing 100094China Weichai Power Co. Ltd.Weifang 261061China Key Laboratory of Marine Materials and Related Technologies Zhejiang Key Laboratory of Marine Materials and Protective TechnologiesNingbo Institute of Materials Technology and Engineering(NIMTE)Chinese Academy of SciencesNingbo 315201China

The random distribution of graphene in epoxy matrix hinders the further applications of grapheneepoxy composites in the field of tribology.Hence,in order to fully utilize the anisotropic properties of graphene,highly aligned graphene-epoxy composites(AGEC)with horizontally oriented structure have been fabricated via an improved vacuum filtration freeze-drying method.The frictional tests results indicated that the wear rate of AGEC slowly increased from 5.19x10^(-6)mm^(3)/(N-m)to 2.87x10^(-5)mm^(3)/(N-m)with the increasing of the normal load from 2 to 10 N,whereas the friction coefficient(COF)remained a constant of 0.109.Compared to the neat epoxy and random graphene-epoxy composites(RGEC),the COF of AGEC was reduced by 87.5%and 71.2%,and the reduction of wear rate was 86.6%and 85.4%at most,respectively.Scanning electron microscope(SEM)observations illustrated that a compact graphene self-lubricant film was formed on the worn surface of AGEC,which enables AGEC to possess excellent tribological performance.Finally,in light of the excellent tribological properties of AGEC,this study highlights a pathway to expand the tribological applications of graphene-epoxy composites.

关键词： graphene aligned epoxy composite tribological performance

来源：

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

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：