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Journal of the Op.r.tions research Society of china 2024年第2期12卷 446-460页

作者： wei gao wei-Fan Wang School of Information Science and Technology Yunnan Normal UniversityKunming 650500YunnanChina Dep.r.ment of Mathematics Zhejiang Normal UniversityJinhua 321004ZhejiangChina

The main contribution in this article is threefold:(1)we show the necessary and sufficient condition for graphs to be fractional(g,f)-covered which can be expressed in different forms,and extended to fractional(g,f,m)-covered graphs;(2)the concept of fractional-critical covered graph is put forward and its necessary and sufficient condition is given;(3)we present the degree condition for a graph to be fractional(g,f,n′,m)-critical covered,and show that degree bound is sharp when m is ***,the related result in fractional(a,b,n′,m)-critical covered setting is also verified.

关键词： Network Fractional factor Data transmission Fractional covered graph Fractional critical covered graph

A novel cascaded H-bridge photovoltaic inverter with flexible arc sup.r.ssion function

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Global Energy Interconnection 2024年第4期7卷 513-527页

作者： Junyi Tang wei gao College of Electrical Engineering and Automation Fuzhou UniversityFuzhou 350108P.R.China

This pap.r.presents a novel ap.r.ach that simultaneously enables photovoltaic(pV)inversion and flexible arc sup.r.ssion during single-phase grounding *** compensate for ground currents through an arc-elimination function,while outputting a pV direct current(DC)power *** method effectively reduces the residual grounding *** reduce the dependence of the arc-sup.r.ssion p.r.ormance on accurate compensation current-injection models,an adaptive fuzzy neural network imitating a sliding mode controller was *** online adaptive adjustment law for network p.r.meters was developed,based on the Lyapunov stability theorem,to improve the robustness of the inverter to fault and connection ***,a new arc-sup.r.ssion control exit strategy is proposed to allow a zerosequence voltage amplitude to quickly and smoothly track a target value by controlling the nonlinear decrease in current and reducing the regulation *** results showed that the proposed method can effectively achieve fast arc sup.r.ssion and reduce the fault impact current in single-phase grounding *** to other methods,the proposed method can generate a lower residual grounding current and maintain good arc-sup.r.ssion p.r.ormance under different transition resistances and fault locations.

关键词： photovoltaic inverter Flexible arc sup.r.ssion Adaptive control Fuzzy neural network Sliding mode control Exit strategy

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Effect of mesop.r. spatial distribution of HZSM-5 catalyst on zinc state and product distribution in 1-hexene aromatization

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Chinese Journal of Chemical Engineering 2024年第3期67卷 16-26页

作者： Chenhao wei Di gao Guohao Zhang Liang Zhao Jinsen gao Chunming Xu The State Key Lab of Heavy Oil processing China University of Petroleum(Beijing)Beijing 102249China SINOpEC research Institute of petroleum processing Co. Ltd.Beijing 100083China

1-hexene aromatization is a promising technology to convert excess olefin in fluid catalytic cracking(FCC)gasoline to high-value benzene(B),toluene(T),and ***,the increasing market demand of xylene has put forward higher requirements for new generation of *** increasing xylene yield in 1-hexene aromatization,the effect of mesop.r. structure and spatial distribution on product distribution and Zn loading was *** with different mesop.r. spatial distribution were prep.r.d by post-treatment of p.r.nt HZSM-5 zeolite,including NaOH treatment,tetra-propylammonium hydroxide(TpAOH)treatment,and *** was found the evenly distributed mesop.r. mainly prolongs the catalyst lifetime by enhancing diffusion prop.r.ies but reduces the aromatics selectivity,as a result of damage of microp.r.s close to the catalyst *** the selectivity of high-value xylene can be highly promoted when the mesop.r. is mainly distributed interior the ***,the state of loaded Zn was also affected by mesop.r.s spatial *** the optimized catalyst,the xylene selectivity was enhanced by 12.4%comp.r.d with conventional Zn-loaded p.r.nt HZSM-5 catalyst at conversion over 99%.It was attributed to the synergy effect of mesop.r.s spatial distribution and optimized acid *** work reveals the role of mesop.r.s in different spatial positions of 1-hexene aromatization catalysts in the reaction process and the influence on metal distribution,as well as their synergistic effect two on the improvement of xylene selectivity,which can improve our understanding of catalyst p.r. structure and be helpful for the rational design of high-efficient catalyst.

关键词： 1-Hexene aromatization Alkali treatment Xylene selectivity Mesop.r.s Zinc state

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Flow Field Simulation and p.r.meter Analysis of Hydraulic Unbalanced Bionic Self-recovery Actuator for rotary Equipment

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Journal of Bionic Engineering 2024年第1期21卷 325-343页

作者： wei Li Xin pan Dehong Ge Jinji gao Key Laboratory of Engine Health Monitoring-Control and Networking of Ministry of Education Beijing University of Chemical TechnologyBeijing 100029China Beijing Key Laboratory of High-End Mechanical Equipment Health Monitoring and Self-recovery Beijing University of Chemical TechnologyBeijing 100029China

The rotor is the most imp.r.ant component of rotating machinery,and the vibration produced by its mass unbalance has a serious influence on the secure and steady op.r.tion of the machine,so an effective online sup.r.ssion technology is urgently needed.A new hydraulic unbalanced bionic self-recovery system is introduced,imitating the way of manually repairing faulty *** accomplish the effect of actuator mass redistribution,the technology employs pressurized air to drive the quantitative transfer of liquid in the reservoir cavity at opposite *** can complete the online adjustment of the equipment's balancing state and sup.r.ss the unbalanced vibration of equipment in real time,which gives the equipment the ability to maintain an autonomous health state and improve equipment *** composition and working principle of the system are introduced in detail,and the key p.r.ormance p.r.meters,such as the minimum running speed and the balancing liquid transfer speed,are analyzed *** fluid-solid coupling model of the actuator was established,and the two-phase flow from inside the hydraulic unbalanced bionic self-recovery actuator was simulated under multiple working conditions and the p.r.ormance p.r.meters were quantitatively analyzed.A balancing simulation test bed was built,and its effectiveness was verified by p.r.ormance p.r.meter tests and unbalanced bionic self-recovery *** exp.r.mental results show that the mass distribution adjustment of the balancing disk can be achieved using different viscosity balancing liquid,and the response of liquid viscosity 10 cSt is faster than that of liquid viscosity 100 cSt in the process of balancing liquid transfer,and the time is reduced by more than 75%;the system can reduce the simulated rotor amplitude from 18.3μm to 10.6μm online in real time,which provides technical supp.r. for the subsequent development of a new generation of bionic intelligent equipment.

关键词： Engineering self-recovery-Bionics Simulation analysis Self-recovery regulation

Effect of oxide inclusions on MnS precipitates and tensile mechanical prop.r.y of high-strength low-alloy steel

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Journal of Iron and Steel research International 2024年第5期31卷 1210-1220页

作者： Xiao-yong gao Hong wei Li-feng Zhang School of Mechanical Engineering Yanshan UniversityQinhuangdao066004HebeiChina School of Materials Science and Engineering Yanshan UniversityQinhuangdao066004HebeiChina School of Mechanical and Materials Engineering North China University of TechnologyBeijing100144China

The key role of oxide inclusions on the microstructure and mechanical prop.r.y of a high-strength low-alloy steel was *** field emission scanning electron microscope equipped with energy-disp.r.ive spectrometry was used to characterize MnS *** inclusions play an imp.r.ant role in the shape control of MnS *** oxides fovored to decrease the size and the aspect ratio of MnS *** less oxide inclusions in the steel,ap.r.ximately over 16.7%MnS precipitates were with aspect ratio a>5 and p.r. MnS precipitates accounted for 75.9%in ***,with more oxide inclusions in the steel,only 7.4%MnS precipitates were with a>5 and p.r. MnS precipitates accounted for 60.1%in *** of MnS by oxide inclusions improved the strength and inhibited the *** oxide inclusions in the steel increased the yield strength and tensile strength of the steel in both longitudinal and transverse directions,and lowered the anisotropy of the mechanical prop.r.y.

关键词： High-strength low-alloy steel MnS Oxide inclusion Mechanical prop.r.y Anisotropy

Spatial distribution of supra-p.r.afrost groundwater in the Qinghai-Tibet Engineering Corridor using inversion models

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Advances in Climate Change research 2024年第1期15卷 31-41页

作者： Yu gao Ming-Tang CHAI wei MA Yu-Tao gao State Key Laboratory of Frozen Soils Engineering Northwest Institute of Eco-Environment and ResourcesChinese Academy of SciencesLanzhou 73000China School of Engineering Science University of Chinese Academy of SciencesBeijing 100049China School of Civil and Hydraulic Engineering Ningxia UniversityYinchuan 750021China

Supra-p.r.afrost groundwater(SpG)is a key factor that causes damage to highways and railways in the Qinghai-Tibet Engineering Corridor(QTEC).It is difficult to monitor SpG in the field due to their complex formation mechanisms and movement *** single-site field monitoring studies limit the spatial and temp.r.l precision of SpG spatial *** determine the moisture content of shallow soils and the SpG distribution along the QTEC,this work employed the temp.r.ture vegetation dryness index and remote sensing models for groundwater table distribution *** accuracies of the models were validated using mea-surements obtained from different sites in the *** the p.r.afrost zones of the QTEC,72%,22%and 6%of the SpG were located at depths of 0.5-1,1 m,***,79.4%of the area along the Qinghai-Tibet Highway(QTH)(Xidatan-Tanggula)section contained *** these sections with SpG,37.9%have an SpG table at depths of 0.5-0.8 *** study preliminarily explored the SpG distribution in the QTEC with a 30 m *** findings can help improve the spatial scale of SpG research,provide a basis for the analysis of the hydrothermal mechanisms,and serve as a guide in the assessment of op.r.tional risks and road structure designs.

关键词： Dryness index Landsat Soil moisture Groundwater level Qinghai-Tibet Engineering Corridor

Lift-Off Effect of Koch and Circular Differential pickup Eddy Current probes

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Chinese Journal of Mechanical Engineering 2024年第2期37卷 283-293页

作者： Guolong Chen Zheng Cao Shuaishuai Zhang Ji wei wei gao Wuyin Jin School of Mechanical and Electrical Engineering Lanzhou University of TechnologyLanzhou 730050China

A flexible or planar eddy current probe with a differential structure can sup.r.ss the lift-off noise during the inspection of ***,the extent of the lift-off effect on differential probes,including different coil structures,*** this study,two planar eddy current probes with differential pickup structures and the same size,Koch and circular probes,were used to comp.r. lift-off *** eddy current distributions of the probes p.r.urbed by 0°and 90°cracks were obtained by finite element *** analysis results show that the 90°crack can impede the eddy current induced by the Koch probe even further at relatively low lift-off *** peak-to-peak values of the signal output from the two probes were comp.r.d at different lift-off distances using finite element analysis and exp.r.mental *** addition,the effects of different frequencies on the lift-off were studied *** results show that the signal peak-to-peak value of the Koch probe for the inspection of cracks in 90°orientation is larger than that of the circular probe when the lift-off distance is smaller than 1.2 *** addition,the influence of the lift-off distance on the peak-to-peak signal value of the two probes was studied via *** indicates that the influence becomes more evident with an increase in excitation *** research discloses the lift-off effect of differential planar eddy current probes with different coil shapes and proves the detection merit of the Koch probe for 90°cracks at low lift-off distances.

关键词： Eddy current testing Differential pickup probe Fractal Koch curve Flexible eddy current probe

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On-surface synthesis and characterization of polyynic carbon chains

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National Science review 2024年第3期11卷 192-199页

作者： Wenze gao wei Zheng Luye Sun Faming Kang Zheng Zhou wei Xu Interdisciplinary Materials research Center School of Materials Science and Engineering Tongji University

Carbyne, an elusive sp-hybridized linear carbon allotrope, has fascinated chemists and physicists for decades. Due to its high chemical reactivity and extreme instability, carbyne was much less explored in contrast to the sp2-hybridized carbon allotropes such as graphene. Herein, we rep.r. the on-surface synthesis of polyynic carbon chains by demetallization of organometallic polyynes on the Au（111） surface;the longest one observed consists of ～60 alkyne units（120 carbon atoms）. The polyynic structure of carbon chains with alternating triple and single bonds was unambiguously revealed by bond-resolved atomic force microscopy. Moreover, an atomically precise polyyne, C14, was successfully produced via tip-induced dehalogenation and ring-opening of the decachloroanthracene molecule(C14Cl10) on a bilayer NaCl/Au（111） surface at 4.7 K, and a band gap of 5.8 eV was measured by scanning tunnelling spectroscopy,in a good agreement with the theoretical HOMO–LUMO gap（5.48 eV）.

关键词： polyyne scanning probe microscopy carbon allotrope on-surface synthesis organometallic polyyne

preface: The Special Issue on Dynamic and Networking Games

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Journal of the Op.r.tions research Society of china 2024年第1期12卷 1-3页

作者： Hong-wei gao Vladimir Mazalov School of Mathematics and Statistics Qingdao University266071QingdaoShandongChina Institute of Applied Mathematical research Karelian Research Centre of RAS185910PetrozavodskRussia

Numerous game theory-based techniques to characterize agent behavior haveemerged in response to the swift advancements in technology,communications,indus-trial organization,economic integration,and international *** is a huge varietyof mathematical techniques used in game *** application of dynamic and net-working game techniques is the main topic of this special *** strategicinteractions between many decision-makers with dynamic and varied connections isthe focus of research in the game theory discipline of dynamic and networking *** field of study examines how agents or people make choices in dynamic circum-stances and how those choices impact their overall outcomes and payoffs.

关键词： agent strategic advancement