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Multi-UAV Collaborative Edge Computing Algorithm for Joint Task Offloading and Channel Resource Allocation

Journal of Communications and Information Networks 2024年第2期9卷 137-150页

作者： yuting Wei Sheng Wu Zhe Ji Zhigang yu Chunxiao jiang Linling Kuang School of Information and Communication Engineering Beijing University of Posts and TelecommunicationsBeijing 100876China China Academy of Electronics and Information Technology Beijing 100041China Beijing National Research Center for Information Science and Technology Tsinghua Space CenterTsinghua UniversityBeijing 100084China

Unmanned aerial vehicle (UAV)-based edge computing is an emerging technology that provides fast task processing for a wider area. To address the issues of limited computation resource of a single UAV and finite communication resource in multi-UAV networks, this paper joints consideration of task offloading and wireless channel allocation on a collaborative multi-UAV computing network, where a high altitude platform station (HAPS)is adopted as the relay device for communication between UAV clusters consisting of UAV cluster heads (ch-UAVs) and mission UAVs (m-UAVs). We propose an algorithm, jointing task offloading and wireless channel allocation to maximize the average service success rate (ASSR)of a period time. In particular,the simulated annealing(SA)algorithm with random perturbations is used for optimal channel allocation,aiming to reduce interference and minimize transmission delay.A multi-agent deep deterministic policy gradient (MADDPG) is proposed to get the best task offloading strategy. Simulation results demonstrate the effectiveness of the SA algorithm in channel allocation. Meanwhile,when jointly considering computation and channel resources,the proposed scheme effectively enhances the ASSR in comparison to other benchmark algorithms.

关键词： UAV-based edge computing multi-UAV collaboration joint task offloading and wireless channel allocation simulated annealing(SA)algorithm multi-agent deep deterministic policy gradient(MADDPG)

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Typhoon-Induced Ocean Waves and Stokes Drift:A Case Study of Typhoon Mangkhut(2018)

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China Ocean Engineering 2024年第4期38卷 711-724页

作者： WU Zhi-yuan GAO Kai CHEN Jie ZHANG hao-jian DENG Bin jiang Chang-bo LIU Yi-zhuang Lyu Zhao YAN Ren School of Hydraulic and Environmental Engineering Changsha University of Science&TechnologyChangsha 410114China Key Laboratory of Water-Sediment Sciences and Water Disaster Prevention of Hunan Province Changsha 410114China State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering Hohai UniversityNanjing 210024China State Key Laboratory of Coastal and Offshore Engineering Dalian University of TechnologyDalian 116024China School of Civil Engineering Hunan University of TechnologyZhuzhou 412007China

Ocean waves and Stokes drift are generated by *** study investigated the characteristics of ocean waves and wave-induced Stokes drift and their effects during Typhoon Mangkhut using European Centre for MediumRange Weather Forecasts(ECMWF)ERA5 datasets and observational *** results revealed that the typhoon generated intense cyclones and huge typhoon waves with a maximum wind speed of 45 m/s,a minimum pressure of955 h Pa,and a maximum significant wave height of 12 *** Stokes drift caused by typhoon waves exceeded 0.6m/s,the Stokes depth scale exceeded 18 m,and the maximum Stokes transport reached 6 m^(2)/*** spatial distribution of 10-m wind speed,typhoon wave height,Stokes drift,Stokes depth,and Stokes transport during the typhoon was highly correlated with the typhoon *** distribution along the typhoon track showed significant zonal asymmetry,with greater intensity on the right side of the typhoon track than on the left *** findings provide important insights into the impact of typhoons on ocean waves and Stokes drift,thus improving our understanding of the interactions between typhoons and the ocean *** study also investigated the contribution of Stokes transport to the total net transport during typhoons using Ekman-Stokes Numbers as a comparative *** results indicated that the ratio of Stokes transport to the total net transport reached up to 50%within the typhoon radius,while it was approximately 30%outside the *** Stokes transport induced by typhoon waves led to divergence in the transport direction,which resulted in upwelling of the lower ocean as a compensation ***,Stokes transport played a crucial role in the vertical mixing of the ocean during *** findings suggested that Stokes transport should be paid more attention to,particularly in high latitude ocean regions,where strong winds can amplify its effects.

关键词： Stokes drift typhoon waves Ekman-Stokes transport vertical mixing Typhoon Mangkhut

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Effect of Al content on modification behavior of non-metallic inclusions in high-strength steel treated with rare earth

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Journal of Iron and Steel Research International 2024年第8期31卷 1886-1899页

作者： Zhan-peng Tie Xue-yuan jiang Hai-yan Tang ·Gen Li yu-hang Wang Jia-quan Zhang School of Metallurgical and Ecological Engineering University of Science and Technology BeijingBeijing 100083China Continuous Casting Business Section CISDI Engineering Co.Ltd.Chongqing 401122China Special Steel Institute Central Iron and Steel Research Institute Co.Ltd.Beijing 100081China

The influence of Al content(0.0053,0.0171,and 0.0578 wt.%)on the modification behavior of non-metallic inclusions in 20CrMoVTiB steel treated with rare earth elements was studied through high-temperature experiments and thermodynamic *** results showed that the modification products varied with the Al content in steel under 0.01 wt.%of Ce *** formation sequence of typical rare earth inclusions in steel with the increase in Al content was Ce_(2)O_(3)→CeAlO_(3)→CeAl_(11)O_(18),and the final stable products were highly Al content *** the Al content was 0.0053 wt.%,the stable phase in steel was Ce2O3;while the[Al]reached 0.0171 wt.%,the stable phase became CeA1O_(3).As the A1 content reached 0.0578 wt.%,CeAl_(11)O_(18) became the stable *** a result,increasing the Al content could inhibit the precipitation of Ce_(2)O_(3) inclusions in steel while promote the formation of CeAIO3 and CeAl_(11)O_(18) *** addition,both Ca treatment and Ce treatment could effectively refine the size of inclusions in steel by changing their ***,the feeding amount of Ca wire into molten steel should be appropriately reduced under the condition of adding Ce simultaneously,which is expected to be beneficial for an improved Ce treatment effect.

关键词： Rare earth Al content Steel Inclusion Thermodynamics Ca treatment

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Electrocatalytic NAD(P)H regeneration for biosynthesis

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Green Chemical Engineering 2024年第1期5卷 1-15页

作者： Yaoxuan Li Guanhua Liu Weixi Kong Suoqing Zhang yuemei Bao hao Zhao Lihui Wang Liya Zhou Yanjun jiang National-Local Joint Engineering Laboratory for Energy Conservation in Chemical Process Integration and Resources Utilization School of Chemical Engineering and TechnologyHebei University of TechnologyTianjin300401China North China Pharmaceutical Group Corp Shijiazhuang050015China Tianjin Food Research Institute Tianjin301609China

The highly efficient chemoselectivity,stereoselectivity,and regioselectivity render enzyme catalysis an ideal pathway for the synthesis of various chemicals in broad *** the cofactor of an enzyme is necessary but expensive,the conversed state of the cofactor is not beneficial for the positive direction of the *** regeneration using electrochemical methods has the advantages of simple operation,low cost,easy process monitoring,and easy product separation,and the electrical energy is green and ***,bioelectrocatalysis has great potential in synthesis by combining electrochemical cofactor regeneration with enzymatic *** this review,we detail the mechanism of cofactor regeneration and categorize the common electron mediators and enzymes used in cofactor *** reaction type and the recent progress are summarized in electrochemically coupled enzymatic *** main challenges of such electroenzymatic catalysis are pointed out and future developments in this field are foreseen.

关键词： Biosynthesis Cofactor regeneration Bioelectrocatalysis NAD(P)H Electron mediator

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Interface interaction between SiO_(2) and magnetite under high temperature:particle migration and inhibition mechanism

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Journal of Iron and Steel Research International 2024年第3期31卷 561-572页

作者： Yao-zu Wang Jian-liang Zhang Qiang Cheng Hui-qing jiang Zheng-jian Liu yu-bo Tan School of Intelligent Science and Technology University of Science and Technology BeijingBeijing 100083China School of Metallurgical and Ecological Engineering University of Science and Technology BeijingBeijing 100083China School of Advanced Engineering University of Science and Technology BeijingBeijing 100083China

Silicon is one of the main gangue components in iron ore,usually in the form of quartz and *** studies have shown that SiO_(2) has a two-sided effect on the consolidation of pellets during high-temperature oxidation roasting of ***,it is very difficult to capture the structural evolution and migration mechanisms during high-tem-perature roasting process by existing experimental ***,the influence of SiO_(2) on the consolidation behavior of magnetite was studied through a series of roasting experiments and molecular dynamic *** results show that the consolidation index and particle growth index decrease with the increase in SiO_(2) content in the *** 1573 K,the liquid phase promotes the recrystallization growth of hematite at high *** dynamic study shows that it is difficult for quartz SiO_(2) to form sintering neck with Fe_(2)O_(3).When the calcination temperature is higher than 1400 K,the Fe_(2)O_(3)-Fe_(2)SiO_(4) system produces a considerable sintering neck structure after *** atomic migration ability of Fe_(2)SiO_(4) is much higher than that of Fe_(2)O_(3).The higher atomic migration ability of Fe_(2)SiO_(4) is the main reason for the formation of the sintering neck.

关键词： Sintering neck Crystal growth Consolidation Molecular dynamics SiO_(2)

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Chemical modification of barite for improving the performance of weighting materials for water-based drilling fluids

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Petroleum Science 2024年第1期21卷 551-566页

作者： Li-Li Yang Ze-yu Liu Shi-bo Wang Xian-Bo He Guan-Cheng jiang Jie Zhang MOE Key Laboratory of Petroleum Engineering State Key Laboratory of Petroleum Resources and ProspectingChina University of Petroleum(Beijing)Changping DistrictBeijing102249China MOE Key CNPC Drilling Research Institute Changping DistrictBeijing102206China

With increasing drilling depth and large dosage of weighting materials,drilling fluids with high solid content are characterized by poor stability,high viscosity,large water loss,and thick mud cake,easier leading to reservoir damage and wellbore *** this paper,micronized barite(MB)was modified(mMB)by grafting with hydrophilic polymer onto the surface through the free radical polymerization to displace conventional API barite *** suspension stability of water-based drilling fluids(WBDFs)weighted with API barite:mMB=2:1 in 600 g was significantly enhanced compared with that with API barite/WBDFs,exhibiting the static sag factor within 0.54 and the whole stability index of *** viscosity and yield point reached the minimum,with a reduction of more than 40%compared with API barite only at the same *** multi-stage filling and dense accumulation of weighting materials and clays,filtration loss was decreased,mud cake quality was improved,and simultaneously it had great reservoir protection performance,and the permeability recovery rate reached 87%.In addition,it also effectively improved the lubricity of *** sticking coefficient of mud cake was reduced by 53.4%,and the friction coefficient was ***,mMB can serve as a versatile additive to control the density,rheology,filtration,and stability of WBDFs weighted with API barite,thus regulating comprehensive performance and achieving reservoir protection *** work opened up a new path for the productive drilling of extremely deep and intricate wells by providing an efficient method for managing the performance of high-density WBDFs.

关键词： Drilling fluids Weighting materials Filtration control Reservoir protection Stability property

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Enhancing thermoelectric performance of p-type SnTe through manipulating energy band structures and decreasing electronic thermal conductivity

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Rare Metals 2024年第7期43卷 3232-3241页

作者： Xin Qian hao-Ran Guo Jia-Xin Lyu Bang-Fu Ding Xing-yuan San Xiao Zhang jiang-Long Wang Shu-Fang Wang Hebei Key Lab of Optic-Electronic Information and Materials College of Physics Science and TechnologyHebei UniversityBaoding 071002China College of Electron and Information Engineering Hebei UniversityBaoding 071002China Research Institute for Frontier Science Beihang UniversityBeijing100191China

SnTe has received considerable attention as an environmentally friendly alternative to the representative thermoelectric material of ***,excessive hole carrier concentration in SnTe results in an extremely low Seebeck coefficient and high thermal conductivity,which makes it exhibit relatively inferior thermoelectric *** this work,the thermoelectric performance of p-type SnTe is enhanced through regulating its energy band structures and reducing its electronic thermal conductivity by combining Bi doping with CdSe ***,the carrier concentration of SnTe is successfully suppressed via Bi doping,which significantly decreases the electronic thermal ***,the convergence and flattening of the valence bands by alloying CdSe effectively improves the effective mass of SnTe while restraining its carrier ***,a maximum figure of merit(ZT) of~ 0.87 at 823 K and an average ZT of~ 0.51 at 300-823 K have been achieved in Sn_(0.96)Bi_(0.04)Te-5%*** results indicate that decreasing the electronic thermal conductivity is an effective means of improving the performance of thermoelectric materials with a high carrier concentration.

关键词： Thermoelectric materials SnTe Energy band structure Electronic thermal conductivity ZT value

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Color coded metadevices toward programmed terahertz switching

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Light(Science & Applications) 2024年第7期13卷 1383-1392页

作者： Weibao He Xiang’ai Cheng Siyang Hu Ziheng Ren Zhongyi yu Shun Wan yuze Hu Tian jiang College of Advanced Interdisciplinary Studies National University of Defense TechnologyChangshaChina. Nanhu Laser Laboratory National University of Defense TechnologyChangshaChina. Hunan Provincial Key Laboratory of High Energy Laser Technology National University of Defense TechnologyChangshaChina. Institute for Quantum Science and Technology College of ScienceNational University of Defense TechnologyChangshaChina

Terahertz modulators play a critical role in high-speed wireless communication,non-destructive imaging,and so on,which have attracted a large amount of research ***,all-optical terahertz modulation,an ultrafast dynamical control approach,remains to be limited in terms of encoding and *** we experimentally demonstrated an optical-programmed terahertz switching realized by combining optical metasurfaces with the terahertz metasurface,resulting in 2-bit dual-channel terahertz *** terahertz metasurface,made up of semiconductor islands and artificial microstructures,enables effective all-optical programming by providing multiple frequency channels with ultrafast modulation at the nanosecond ***,optical metasurfaces covered in terahertz metasurface alter the spatial light field distribution to obtain color *** to the time-domain coupled mode theory analysis,the energy dissipation modes in terahertz metasurface can be independently controlled by color excitation,which explains the principle of 2-bit encoding *** work establishes a platform for all-optical programmed terahertz metadevices and may further advance the application of composite metasurface in terahertz manipulation.

关键词： terahertz surface excitation

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Understanding the spatial interaction of ultrasounds based on three-dimensional dual-frequency ultrasonic field numerical simulation

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China Foundry 2024年第1期21卷 29-43页

作者： Zhao-yang Yin Qi-chi Le Yan-chao jiang Da-zhi Zhao Qi-yu Liao Qi Zou Key Lab of Electromagnetic Processing of Materials Ministry of EducationNortheastern UniversityShenyang 110819China School of Materials Science and Engineering Northeastern UniversityShenyang 110819China

A transient 3D model was established to investigate the effect of spatial interaction of ultrasounds on the dual-frequency ultrasonic field in magnesium alloy *** effects of insertion depth and tip shape of the ultrasonic rods,input pressures and their ratio on the acoustic field distribution were discussed in ***,the spacing,angle,and insertion depth of two ultrasonic rods significantly affect the interaction between distinct *** a result,various acoustic pressure distributions and cavitation regions are *** spherical rods mitigate the longitudinal and transversal attenuation of acoustic pressure and expand the cavitation volume by 53.7%and 31.7%,respectively,compared to the plate and conical *** the input pressure will enlarge the cavitation region but has no effect on the acoustic pressure distribution *** acoustic pressure ratio significantly affects the pressure distribution and the cavitation region,and the best cavitation effect is obtained at the ratio of 2:1(P15:P20).

关键词： dual-frequency ultrasonic numerical model acoustic pressure spatial interaction magnesium alloy

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Synthesis of spherical nano-ZSM-5 zeolite with intergranular mesoporous for alkylation of ethylbenzene with ethanol to produce m-diethylbenzene

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Chinese Journal of Chemical Engineering 2024年第3期67卷 298-309页

作者： Siyue Wang Jinhong Li Qingxin Xu Shengjie Song yu'ni jiang Lidong Chen Xin Shi Weiguo Cheng Faculty of Chemistry and Chemical Engineering Liaoning Normal UniversityDalian 110629China Beijing Key Laboratory of Ionic Liquids Clean Process Key Laboratory of Green Process and EngineeringInstitute of Process EngineeringChinese Academy of SciencesBeijing 100190China

Catalytic synthesis of m-diethylbenzene(m-DEB)through alkylation of ethylbenzene(EB)may be a promising alternative route in comparison with traditional rectification of mixed DEB,for which the top priority is to develop efficient and stable heterogeneous ***,the spherical nano-ZSM-5 zeolite with abundant intergranular mesoporous is synthesized by the seed-mediated growth method for alkylation of EB with ethanol to produce *** results show that the spherical nano-ZSM-5 zeolite exhibits better stability and higher alkylation activity at a lower temperature than those of commercial micropore *** then,the spherical nano-ZSM-5 is further modified by La_(2)O_(3) through acid treatment followed by immersion *** acid treatment causes nano-ZSM-5 to exhibit the increased pore size but decreased the acid sites,and subsequent La_(2)O_(3) loading reintroduces the weak acid *** a result,the HNO_(3)-La_(2)O_(3)-modified catalyst exhibits a slight increase in EB conversion and DEB yield in comparison with unmodified one,and meanwhile,it still maintains high m-DEB *** catalyst after acid treatment achieves higher catalytic stability besides maintaining the high alkylation activity of EB with *** present study on the spherical nano-HZSM-5 zeolite and its modification catalyst with excellent alkylation ability provides new insights into the production of mDEB.

关键词： Zeolite Modification Alkylation reaction m-diethylbenzene Catalyst Fixed-bed

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