检索结果-南通市图书馆

A Hybrid Approach to Maximize the Lifetime of Directional Sensor Networks with Smoothly Varying Sensing Ranges

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Electronics 2017年第4期26卷 703-709页

作者： LIU Shufen GAO Sihua BAO Tie zhang yikun College of Computer Science and Technology Jilin University

The difficulty of maximizing the lifetime in directional sensor networks has gained increasing attention recently. Most of the existing studies are focused on directional sensors with single or several predefined sensing ranges. In the present study, directional sensors can change sensing ranges smoothly. We address the problem of maximizing the lifetime in directional sensor networks with such smoothly varying sensing ranges,and propose a hybrid approach that combines a column generation method with an immune genetic algorithm. We search for attractive columns with the genetic algorithm, and optimize them by designing dynamic vaccines. Computational results demonstrate the performance of the proposed approach. Meanwhile,the advantage of the mentioned sensors in terms of solution quality is also revealed.

关键词： Directional sensor networks Column generation Immune genetic algorithm

Achievement of giant cryogenic refrigerant capacity in quinary rare-earths based high-entropy amorphous alloy

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2022年第7期102卷 66-71页

作者： yikun zhang Jian Zhu Shuo Li Jiang Wang Zhongming Ren State Key Laboratory of Advanced Special Steels&Shanghai Key Laboratory of Advanced Ferrometallurgy&School of Materials Science and Engineering Shanghai UniversityShanghai 200444China

Magnetic refrigeration(MR)by utilizing the magnetocaloric(MC)effect is recognized as one of the most potential promising solid state environmentally friendly and high efficiency alternative method to the well-used state-of-the-art gas compression cooling *** this work,a systematic investigation of quinary equi-atomic rare-earths(RE)based Er_(20) Ho_(20) Gd_(20) Ni_(20) Co_(20) high-entropy(HE)amorphous alloy in terms of the microstructure,magnetic and magnetocaloric(MC)properties have been *** Er_(20) Ho_(20) Gd_(20) Ni_(20) Co_(20) exhibits promising glass forming ability with an undercooled liquid region of 72 *** cryogenic MC performances can be found in wide temperature from∼25 and∼75 K,close to H_(2) and N_(2) liquefaction,*** from the largest magnetic entropy change(-S M)reaches 17.84 J/(kg K)with 0-7 T magnetic field change,corresponding refrigerant capacity(RC)attains a giant value of 1030 J/*** promising cryogenic MC performances together with the unique HE amorphous characterizations make the quinary Er_(20) Ho_(20) Gd_(20) Ni_(20) Co_(20) HE amorphous alloy attractive for cryogenic MR applications.

关键词： HE-amorphous ribbons Magnetocaloric performances Rare earths Magnetic properties Giant refrigerant capacity

Multi-Objective Redundancy Optimization of Continuous-Point Robot Milling Path in Shipbuilding

在线全文

学校读者我要写书评

暂无评论

Computer Modeling in Engineering & Sciences 2023年第2期134卷 1283-1303页

作者： Jianjun Yao Chen Qian yikun zhang Geyang Yu College of Mechanical and Electrical Engineering Harbin Engineering UniversityHarbin150001China

The 6-DOF manipulator provides a new option for traditional shipbuilding for its advantages of vast working space,low power consumption,and excellent ***,the rotation of the end effector along the tool axis is functionally redundant when using a robotic arm for five-axis *** the process of ship construction,the performance of the parts’protective coating needs to bemachined tomeet the Performance Standard of Protective Coatings(PSPC).The arbitrary redundancy configuration in path planning will result in drastic fluctuations in the robot joint angle,greatly reducing machining quality and *** have been some studies on singleobjective optimization of redundant variables,However,the quality and efficiency of milling are not affected by a single factor,it is usually influenced by several factors,such as the manipulator stiffness,the joint motion smoothness,and the energy *** solve this problem,this paper proposed a new path optimization method for the industrial robot when it is used for five-axis *** path smoothness performance index and the energy consumption index are established based on the joint acceleration and the joint velocity,*** path planning issue is formulated as a constrained multi-objective optimization problem by taking into account the constraints of joint limits and singularity ***,the path is split into multiple segments for optimization to avoid the slow convergence rate caused by the high *** algorithm combining the non-dominated sorting genetic algorithm(NSGA-II)and the differential evolution(DE)algorithm is employed to solve the above optimization *** simulations validate the effectiveness of the algorithm,showing the improvement of smoothness and the reduction of energy consumption.

关键词： Shipbuilding robot milling functional redundancy path optimization multi-objective

Exploration of the rare-earth cobalt nickel-based magnetocaloric materials for hydrogen liquefaction

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

Journal of Materials Science & Technology 2023年第28期159卷 163-169页

作者： yikun zhang Jiayu Ying Xinqiang Gao Zhaojun Mo Jun Shen Lingwei Li School of Electronics and Information&Key Laboratory of Novel Materials for Sensor of Zhejiang Province Hangzhou Dianzi UniversityHangzhou 310012China Ganjiang Innovation Academy Chinese Academy of SciencesGanzhou 341119China

Magnetic refrigeration based on the magnetocaloric effect(MCE)of magnetic solids has been considered as an emerging technology for hydrogen ***,the lack of high-performance materials has slowed the development of any practical ***,we present a family of rare-earth cobalt nickel-based magnetocaloric materials,namely Dy_(1-x)Ho_(x)CoNi and Ho_(1-x)Er_(x)CoNi compounds,and system-atically investigated their structural and magnetic properties as well as the MCE and magnetocaloric *** of these compounds crystallize in the C15-type Laves-phase structure and undergo typi-cal second-order magnetic phase transition(MPT).The change in magnetism and the MPT temperature for the Dy_(1-x)Ho_(x)CoNi and Ho_(1-x)Er_(x)CoNi compounds originate from the exchange interactions between nearest-neighbor RE 3+ion *** hysteresis magnetocaloric effect was achieved,and the MPT tem-perature of these compounds could be tuned from the liquefaction temperature of nitrogen(∼77 K)to hydrogen(∼20 K)by adjusting the ratio of rare-earth *** study’s findings indicate that theDy_(1-x)Ho_(x)CoNi and Ho_(1-x)Er_(x)CoNi compounds are of potential for practical magnetic refrigeration applica-tions in the field of hydrogen liquefaction.

关键词： Magnetocaloric effect Hydrogen liquefaction Rare earth Magnetocaloric performance Magnetic refrigeration

Operando investigation of particle re-entrainment mechanism in electrostatic capture process on the lab-on-a-chip

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

Journal of Environmental Sciences 2024年第2期136卷 337-347页

作者： Yong Zhu yikun zhang Xiaoyong Yang Shanlong Tao Mingxia Chen Wenfeng Shangguan Research Center for Combustion and Environmental Technology School of Mechanical EngineeringShanghai Jiao Tong UniversityShanghai 200240China

Inhalable particle is a harmful air pollutant that causes a significant threat to people's health and ecological environments,which should be removed to purify air,but there exists limited removal efficiency due to particle ***,Operando observation system based on microscopic visualization method is developed to make in situ test of particle migration,deposition and re-entrainment characteristics on a lab-on-a-chip to achieve the investigation in micro-level *** deposition evolution of charged particles is recorded in electric field region intuitively,which confirms the fracture of particle chain occurs during the growth process of deposited *** captures the instantaneous process that a larger particle with micron size due to the coagulation of submicron particles fractures from main body of the particle chain for the first *** analysis of migration behavior of a single submicron particle near electrode surface demonstrates the direct influence of drag force on the fracture of particle *** work is the first-time visualization of dynamic process and mechanism elucidation of particle re-entrainment at the micron level,and the findings will provide the theory support for the particle re-entrainment mechanism and bring inspires of enhancing capture efficiency of inhalable particle.

关键词： Inhalable particle Re-entrainment mechanism Operando observation Lab-on-a-chip Capture efficiency

RE-NiO_(x)(RE=Ce,Y,La)composite oxides coupled plasma catalysis for benzene oxidation and by-product ozone removal

在线全文

学校读者我要写书评

暂无评论

Journal of Rare Earths 2023年第6期41卷 789-800,I0001页

作者： yikun zhang Zhidong Wei Yong Zhu Shanlong Tao Mingxia Chen Zhixiang zhang Zhi Jiang Wenfeng Shangguan Research Center for Combustion and Environment Technology School of Mechanical EngineeringShanghai Jiao Tong UniversityShanghai 200240China

Plasma-coupled catalysis is a promising volatile organic co mpounds(VOCs) removal technology because of its interactional principles of plasma decomposition and catalytic ***,the problem of harmful by-products is still in trouble.A series of rare earth doped RE-NiO_(x)(RE=Ce,Y,La) composite oxides were synthesized by metal organic frameworks(MOFs)-derived method for coupled plasma oxidation of benzene and by-product ozone *** with plasma alone,the 1%La-NiO_(x)catalyst shows the best enhancement of 50% for benzene conversion with complete removal of a maximum of 800 ppm *** energy consumption for 90% benzene removal efficiency(η90%) is also reduced from 3600 to 1200 J/*** re sults of RE-NiO_(x) catalysts indicate that the doping of La causes interaction and synergistic effect between La and Ni,and the surface oxygen and lattice oxygen with defects play crucial roles in benzene oxidation and ozone decomposition,*** addition,the decomposition mechanism of benzene and ozone under plasma is *** is responsible for the indiscriminate bond breaking in benzene and oxygen to form a variety of organic intermediates and ozone,while the La-NiO_(x) catalyst selectively oxidizes the intermediates to CO_(x)/H2O and decomposes the ozone into oxygen.

关键词： Plasma catalysis Benzene removal By-product ozone control Rare earths doping La-NiO_(x)composite oxide

Table-like shape magnetocaloric effect and large refrigerant capacity in dual-phase HoNi/HoNi2 composite

在线全文

学校读者我要写书评

暂无评论

Chinese Physics B 2020年第10期29卷 484-487页

作者： Dan Guo yikun zhang Yaming Wang Jiang Wang Zhongming Ren State Key Laboratory of Advanced Special Steels&Shanghai Key Laboratory of Advanced Ferrometallurgy&School of Materials Science and Engineering Shanghai UniversityShanghai 200444China

Nowadays,magnetic cooling(MC) technology by using the magnetocaloric effect(MCE) has attracted extensive research interest for its promising practical applications.A constant large/giant MCE covers wide refrigeration temperatures(denote as table-like shape) is beneficial for obtaining high efficiency performance for *** this paper,the HoNi/HoNi2 composite was successfully synthesized by arc-melting method and proved to be composed of HoNi and HoNi2 crystalline phases with weight ratios of 52.4 wt.% and 47.6 wt.%,*** maximum magnetic entropy change(-ΔSMmax)is 18.23 J/(kg·K),and the refrigerant capacity values RC1,RC2,and RC3 are 867.9 J/kg,676.4 J/kg,and 467.8 J/kg with ΔH=0-70 kOe,*** table-like shape MCE and large refrigerant capacity values make the composite attractive for cryogenic MC using the Ericsson cycle.

关键词： HoNi-HoNi2 composite magnetic refrigeration table-like magnetocaloric effect

Magnetic properties and promising cryogenic magneto-caloric performances of Gd_(20)Ho_(20)Tm_(20)Cu_(20)Ni_(20) amorphous ribbons

在线全文

学校读者我要写书评

暂无评论

Chinese Physics B 2021年第1期30卷 493-496页

作者： yikun zhang Bingbing Wu Dan Gu Jiang Wang Zhongming Ren State Key Laboratory of Advanced Special Steels Shanghai UniversityShanghai 200072China Shanghai Key Laboratory of Advanced Ferrometallurgy Shanghai UniversityShanghai 200072China School of Materials Science and Engineering Shanghai UniversityShanghai 200072China

The magnetic cooling utilizing magneto-caloric effect is recognized as promising energy efficiency and environmentally friendly *** we report a systematical study on the microstructures,magnetic properties and cryogenic magneto-caloric performances of the Gd_(20)Ho_(20)Tm_(20)Cu_(20)Ni_(20) amorphous *** is found that the ribbons reveal a second-order phase transition and are accompanied by a table-shaped magneto-caloric *** calculated magneticentropy-change maximum |ΔSM|,temperature averaged entropy change(i.e.,TEC(10)),and refrigerant capacity reach 13.9 J/kg·K,13.84 J/kg-K and 740 J/kg with magnetic field change of 0-7 T,respectively,indicating that the present Gd_(20)Ho_(20)Tm_(20)Cu_(20)Ni_(20) amorphous ribbons are good candidates for magnetic cooling.

关键词： microstructure magneto-caloric effect(MCE) amorphous ribbons magnetic properties

Real-Time Visual Tracking with Compact Shape and Color Feature

在线全文

学校读者我要写书评

暂无评论

Computers, Materials & Continua 2018年第6期55卷 509-521页

作者： Zhenguo Gao Shixiong Xia yikun zhang Rui Yao Jiaqi Zhao Qiang Niu Haifeng Jiang School of Computer Science and Technology China University of Mining and TechnologyXuzhou221116China School of Computer Science The University of AdelaideAdelaideSA 5005Australia

The colour feature is often used in the object *** tracking methods extract the colour features of the object and the background,and distinguish them by a ***,these existing methods simply use the colour information of the target pixels and do not consider the shape feature of the target,so that the description capability of the feature is ***,incorporating shape information often leads to large feature dimension,which is not conducive to real-time object ***,the emergence of visual tracking methods based on deep learning has also greatly increased the demand for computing resources of the *** this paper,we propose a real-time visual tracking method with compact shape and colour feature,which forms low dimensional compact shape and colour feature by fusing the shape and colour characteristics of the candidate object region,and reduces the dimensionality of the combined feature through the Hash *** structural classification function is trained and updated online with dynamic data flow for adapting to the new ***,the classification and prediction of the object are carried out with structured classification *** experimental results demonstrate that the proposed tracker performs superiorly against several state-of-the-art algorithms on the challenging benchmark dataset OTB-100 and OTB-13.

关键词： Visual tracking compact feature colour feature structural learning