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Energy consumption mechanism simulation and experimental study of reciprocating vibration for Chinese wolfberry picking

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International Journal of Agricultural and Biological Engineering 2024年第4期17卷 146-155页

作者： song Mei Dunbing Tang Zhigang Shi Zhiyu song Cheng Shen College of Mechanical and Electrical Engineering Nanjing University of Aeronautics and AstronauticsNanjing 210016China Nanjing Institute of Agricultural Mechanization Ministry of Agriculture and Rural AffairsNanjing 210014China Institute of Chinese Wolfberry Science Ningxia Academy of Agriculture and Forestry SciencesYinchuan 750002China

In order to find out the matching principle of excitation force and energy consumption of reciprocating vibrating Chinese wolfberry picking device,the energy consumption mechanism of reciprocating vibrating Chinese wolfberry picking device is *** to the structural characteristics and operating principle of the picking device,the no-load and load movement and force characteristics of the crank bearing and vibrating component are analyzed,and the theoretical model of energy consumption of the reciprocating vibration picking device is jointly constructed,and the simulation analysis is carried *** results show that the vibrating component and load mass have a significant influence on torque,the load air resistance phase has a significant effect on torque,and the load air resistance and friction coefficient have no significant influence on ***,by building an AC servo motor torque detection system and a torque sensing detection system,verification experiments are carried out,the maximum torque of the preset system is 1.3 N∙m,the rated power is 400 W,the motor frequency is 20 Hz,the amplitude is 15 mm,and the total mass of the vibrating component is 0.143 *** results show that,the no-load operation,the change trend of detected torque is consistent with simulation,the torque model is verified to be *** maximum torque of simulation and detection are 0.52 N∙m and 0.57 N∙m respectively,and the error between test and simulation is 9.6%.For load operation,the maximum torque of five groups of branch loads of 20 g,60 g,100 g,140 g,180 g and 220 g are detected to be 0.73 N∙m,0.74 N∙m,0.75 N∙m,0.82 N∙m and 0.83 N∙m,respectively,and the relationship model between load and torque is obtained by *** research results can provide a theoretical basis which can configure a suitable motor in the reciprocating vibration Chinese wolfberry picking device with a certain load limit.

关键词： Chinese wolfberry branches vibration component load torque power

Online Learning-Based Offloading Decision and Resource Allocation in Mobile Edge Computing-Enabled Satellite-Terrestrial Networks

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China Communications 2024年第3期21卷 230-246页

作者： Tong Minglei Li song Han Wanjiang Wang xiaoxiang School of Information and Communication Engineering Beijing University of Posts and TelecommunicationsBeijing 100876China key Laboratory of Universal Wireless Communications Ministry of EducationBeijing University of Posts and TelecommunicationsBeijing 100876China School of Information and Control Engineering China University of Mining and TechnologyXuzhou 221116China School of Computer Science(National Pilot Software Engineering School) Beijing University of Posts and TelecommunicationsBeijing 100876China

Mobile edge computing(MEC)-enabled satellite-terrestrial networks(STNs)can provide Internet of Things(IoT)devices with global computing ***,the network state information is uncertain or *** deal with this situation,we investigate online learning-based offloading decision and resource allocation in MEC-enabled STNs in this *** problem of minimizing the average sum task completion delay of all IoT devices over all time periods is *** decompose this optimization problem into a task offloading decision problem and a computing resource allocation problem.A joint optimization scheme of offloading decision and resource allocation is then proposed,which consists of a task offloading decision algorithm based on the devices cooperation aided upper confidence bound(UCB)algorithm and a computing resource allocation algorithm based on the Lagrange multiplier *** results validate that the proposed scheme performs better than other baseline schemes.

关键词： computing resource allocation mobile edge computing satellite-terrestrial networks task offloading decision

Privacy-Preserving Frank-Wolfe on Shuffle Model

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Acta Mathematicae Applicatae Sinica 2024年第4期40卷 887-907页

作者： Ling-jie ZHANG Shi-song WU Hai ZHANG School of Mathematics Northwest UniversityXi’an 710127China School of Mathematics and Information Science Baoji University of Arts and SciencesBaoji 721013China China Southern Power Grid Artificial Intelligence Technology Company Limited Guangzhou 510700China

In this paper,we design the differentially private variants of the classical Frank-Wolfe algorithm with shuffle model in the optimization of machine *** weak assumptions and the generalized linear loss(GLL)structure,we propose a noisy Frank-Wolfe with shuffle model algorithm(NoisyFWS)and a noisy variance-reduced Frank-Wolfe with the shuffle model algorithm(NoisyVRFWS)by adding calibrated laplace noise under shuffling scheme in thel_(p)(p∈[1,2])-case,and study their privacy as well as utility guarantees for the H?lder smoothness *** particular,the privacy guarantees are mainly achieved by using advanced composition and privacy amplification by *** utility bounds of the Noisy FWS and NoisyVRFWS are analyzed and obtained the optimal excess population risksO(n-(1+α/4α+log(d)√log(1/δ)/n∈and O(n-1+α/4α+log(d)√log1(+δ)/n^(2)∈with gradient complexity O(n(1+α)^(2)/4α^(2)forα∈[1/√3,1].It turns out that the risk rates under shuffling scheme are a nearly-dimension independent rate,which is consistent with the previous work in some *** addition,there is a vital tradeoff between(α,L)-Holder smoothness GLL and the gradient *** linear gradient complexity O(n)is showed by the parameterα=1.

关键词： differential privacy Frank-Wolfe algorithm privacy amplification shuffle model

Integrability and solutions of a nonsymmetric discrete korteweg-de Vries equation

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Communications in Theoretical Physics 2024年第2期76卷 45-50页

作者： Maebel Mesfun Da-jun Zhang song-lin Zhao Department of Mathematics Shanghai UniversityShanghai 200444China Newtouch Center for Mathematics of Shanghai University Shanghai 200444China Department of Applied Mathematics Zhejiang University of TechnologyHangzhou 310023China

In this paper,we present Lax pairs and solutions for a nonsymmetric lattice equation,which is a torqued version of the lattice potential korteweg-de Vries *** nonsymmetric equation is special in the sense that it contains only one spacing parameter but consists of two consistent cubes with other integrable lattice *** such a multidimensionally consistent property we are able to derive its two Lax pairs and also construct solutions using B?cklund transformations.

关键词： discrete korteweg-de Vries equation nonsymmetric multi-dimensional consistency Backlund transformation solution

Boundary Regularity of Isometries Between Infinitely Flat Complex Domains

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Acta Mathematica Sinica,English Series 2024年第6期40卷 1375-1387页

作者： Jin song LIU Fei TAO Hong Yu WANG Academy of Mathematics and Systems Science Chinese Academy of SciencesBeijing 100190P.R.China School of Mathematical Sciences University of Chinese Academy of SciencesBeijing 100049P.R.China Beijing International Center for Mathematical Research Peking UniversityBeijing 100871P.R.China School of Science Beijing University of Posts and TelecommunicationsBeijing 100876P.R.China key Laboratory of Mathematics and Information Networks(Beijing University of Posts and Telecommunications) Ministry of EducationBeijing 100876P.R.China

In this paper we prove that isometries with respect to the kobayashi metric between certain domains having boundary points at which the boundary is infinitely flat extend continuously to the *** strategy is to reestab... 详细信息

关键词： Boundary extension kobayashi metric isometries

Integrative regulatory mechanisms of stomatal movements under changing climate

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Journal of Integrative Plant Biology 2024年第3期66卷 368-393页

作者： Jingbo Zhang xuexue Chen Yajing song Zhizhong Gong State key Laboratory of Nutrient Use and Management College of Resources and Environmental SciencesNational Academy of Agriculture Green DevelopmentChina Agricultural UniversityBeijing 100193China State key Laboratory of Plant Cell and Chromosome Engineering Institute of Genetics and Developmental BiologyChinese Academy of SciencesBeijing 100101China State key Laboratory of Plant Environmental Resilience College of Biological SciencesChina Agricultural UniversityBeijing 100094China Institute of Life Science and Green Development School of Life SciencesHebei UniversityBaoding 071001China

Global climate change-caused drought stress,high temperatures and other extreme weather profoundly impact plant growth and development,restricting sustainable crop *** cope with various environmental stimuli,plants can optimize the opening and closing of stomata to balance CO_(2)uptake for photosynthesis and water loss from *** cells perceive and integrate various signals to adjust stomatal pores through turgor pressure *** mechanisms and signaling networks underlying the stomatal movements in response to environmental stresses have been extensively studied and *** review focuses on the molecular mechanisms of stomatal movements mediated by abscisic acid,light,CO_(2),reactive oxygen species,pathogens,temperature,and other *** discussed the significance of elucidating the integrative mechanisms that regulate stomatal movements in helping design smart crops with enhanced water use efficiency and resilience in a climate-changing world.

关键词： environmental stress guard cell plant regulatory mechanisms stomatal movements

Influence of Sub-Cloud Secondary Evaporation Effects on the Stable Isotopes in Precipitation of Urumqi Glacier No.1,Eastern Tianshan

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Journal of Earth Science 2024年第1期35卷 177-189页

作者： Mengyuan song Zhongqin Li Feiteng Wang xin Zhang State key Laboratory of Cryospheric Sciences Northwest Institute of Eco-Environment and ResourcesTianshan Glaciological StationChinese Academy of SciencesLanzhou 730000China College of Geography and Environmental Science Northwest Normal UniversityLanzhou 730000China College of Sciences Shihezi UniversityShihezi 832000China

In arid regions,the stable hydrogen and oxygen isotopic composition in raindrops is often modified by sub-cloud secondary evaporation when they descend from cloud base to ground through the unsaturated *** a result of kinetic fractionation,the slope and intercept of the δ^(2)H-δ^(18)O correlation equation *** variation of deuterium excess from cloud base to the ground is often used to quantitatively evaluate the influence of secondary evaporation effect on isotopes in *** on the event-based precipitation samples collected at Urumqi Glacier No.1,eastern Tianshan during four-year observation,the existence and impact of secondary evaporation effects were analyzed by the methods of isotope-evaporation *** high air temperature,small raindrop diameter and precipitation amount,and low relative humidity conditions,the remaining rate of raindrops is small and the change of deuterium excess is large relatively,and the slope and intercept of δ^(2)H-δ^(18)O correlation equation are much lower than those of Global Meteoric Water Line,which mean that the influence secondary evaporation on precipitation *** on the conditions of low air temperature,high relative humidity,heavy rainfall,and large raindrop diameter,the change of deuterium excess is small relatively and the remaining rate of raindrops is large,and the slope and intercept of δ^(2)H-δ^(18)O correlation equation increase,the secondary evaporation is *** isotope-evaporation model described a good linear correlation between changes of deuterium excess and evaporation proportion with the slope of 0.90‰/%,which indicated that an increase of 1%in evaporation may result in a decrease of deuterium excess about 0.90‰.

关键词： stable isotopes meteoric water line deuterium excess sub-cloud secondary evaporation effect precipitation glaciers

Centennial Analysis of Human Activity Intensity and Associated Historical Events in Heilongjiang River Sino-Russo Watershed

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Chinese Geographical Science 2024年第2期34卷 280-293页

作者： song Chaoxue LI xiaoling HE Hongshi Michael SUNDE School of Geographical Sciences Northeast Normal UniversityChangchun 130024China School of Natural Resources University of MissouriColumbia 65211USA

Human activities in a transborder watershed are complex under the influence of domestic policies,international relations,and global *** the forces driving human activity change is important for the development of transborder *** this study,we used global historical land cover data,the hemeroby index model,and synthesized major historical events to analyze how human activity intensity changed in the Heilongjiang River(Amur River in Russia)watershed(HLRW).The results showed that there was a strong spatial heterogeneity in the variation of human activity intensity in the HLRW over the past century(1900-2016).On the Chinese side,the human activity intensity change shifted from the plain areas for agricultural reclamation to the mountainous areas for timber *** the Russian side,human activity intensity changes mostly concentrated along the Trans-Siberian Railway and the Baikal-Amur *** variation of human activity intensity tended to respond to regional events while regionalized variation tends to reflect national policy change or broad international *** similarities and differences between China and Russia in policies and positions in international events resulted in synchronous and asynchronous changes in human activity ***,policy shifts were often confined by the natural features of the *** results reveal the historical origins and fundamental connotations of watershed development and contribute to formulating regional management policies that coordinate population,eco-nomic,social,and environmental activities.

关键词： human activity intensity changes hemeroby index centennial scale Heilongjiang River(Amur River in Russia)watershed China Russia

A theoretical model for impact protection of flexible polymer material

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Theoretical & Applied Mechanics Letters 2024年第3期14卷 217-226页

作者： Huifeng xi Hui Pan song Chen Heng xiao MOE key Lab of Disaster Forecast and Control in Engineering School of Machanics and Construction EngineeringJinan UniversityGuangzhou 510632China Doctor Workstation of xuwen County Guangdong Hydropower Energy Co. Ltd.Xuwen 524100China

The relationship between the protective performance of flexible polymer material and material parameters(elasticmodulus,viscosity coefficient)is explored,an impact collision motion equation between two bodies is establishedfrom the viscoelastic material constitutive,and the relationship between the kinematic response and the materialparameters is *** on the kelvin constitutive model,a theoretical model for impact between the pro-tective body and the protected body is established,then the dynamic response is *** feasibility of themodel was verified by drop hammer experiment,and the material parameters(elastic modulus,viscosity coeffi-cient)were obtained by *** model is discretized and the relationship between local impact response andmaterial parameters is *** discussion results on the relationship between the impact response and theprotective material performance indicate that adjusting the elastic modulus,viscosity coefficient,and thicknessof the protective material can effectively improve protective effect.

关键词： Flexible polymer material Viscoelastic material kelvin modelDynamic response Elastic modulus and viscosity coefficient