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Which Neighborhoods Have Easier Access to Online Home Delivery Services?A Spatiotemporal Accessibility Analysis in Nanjing,China

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Chinese Geographical Science 2024年第4期34卷 722-738页

作者： KONG yu ZHEN Feng ZHANG Shanqi shen lizhen School of Architecture and Urban Planning Nanjing UniversityNanjing 210093China Provincial Engineering Research Center of Smart City Planning and Digital Governance Nanjing 210093China

The rise in online home delivery services(OHDS)has had a significant impact on how urban services are supplied and used in recent *** on the spatial accessibility of OHDS are emerging,but few is known about the temporal dimension of OHDS accessibility as well as the geographic and socioeconomic differences in the spatiotemporal accessibility of *** study measures the spatiotemporal accessibility of four types of OHDS,namely leisure,fresh and convenient,medical,and catering *** geographic and socioeconomic disparities in the spatiotemporal accessibility of these four types of OHDS are then identified using spatial statistical methods and the Kruskal-Wallis test(K-W test).The case study in Nanjing,China,suggests that:1)spatiotemporal accessibility better reflects the temporal variation of OHDS accessibility and avoids overestimation of OHDS accessibility when only considering its spatial dimension.2)The spatiotemporal accessibility of OHDS varies geographically and *** located in the main city or neighborhoods with higher housing prices,higher population density,and higher point of interest(POI)mix have better OHDS spatiotemporal *** study contributes to the understanding of OHDS accessibility from a spatiotemporal perspective,and the empirical insights can assist policymakers in creating intervention plans that take into account variations in OHDS spatiotemporal accessibility.

关键词： online home delivery services(OHDS) spatiotemporal accessibility neighborhoods accessibility differences Nanjing City China

Molecular mechanism of flowering time regulation in Brassica rapa:similarities and differences with Arabidopsis

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Horticultural Plant Journal 2024年第3期10卷 615-628页

作者： Na li Rui yang Shuxing shen Jianjun Zhao State Key laboratory of North China Crop Improvement and Regulation Key Laboratory of Vegetable Germplasm Innovation and Utilization of HebeiCollaborative Innovation Center of Vegetable Industry in HebeiCollege of HorticultureHebei Agricultural UniversityBaodingHebei 071000China

Properly regulated flowering time is pivotal for successful plant *** floral transition from vegetative growth to reproductive growth is regulated by a complex gene regulatory network that integrates environmental signals and internal conditions to ensure that flowering takes place under favorable *** rapa is a diploid Cruciferae species that includes several varieties that are cultivated as vegetable or oil *** time is one of the most important agricultural traits of *** crops because of its influence on yield and *** transition to flowering in *** is regulated by several environmental and developmental cues,which are perceived by several signaling pathways,including the vernalization pathway,the autonomous pathway,the circadian clock,the thermosensory pathway,and gibberellin(GA)*** signals are integrated to control the expression of floral integrators BrFTs and BrSOC1s to regulate *** this review,we summarized current research advances on the molecular mechanisms that govern flowering time regulation in *** and compare this to what is known in Arabidopsis.

关键词： Flowering time Brassica rapa Vernalization Photoperiod

Power equipment vibration visualization using intelligent sensing method based on event-sensing principle

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Global Energy Interconnection 2024年第2期7卷 228-240页

作者： Mingzhe Zhao Xiaojun shen lei Su Zihang Dong Tongji University No.1239 Siping RoadYangpu DistrictShanghai 200092P.R.China State Grid Shanghai Municipal Electric Power Company Electric Power Science Research Institute Shanghai 200437P.R.China Department of Electrical and Electronic Engineering Imperial College LondonLondonSW72AZU.K.

Vibration measurements can be used to evaluate the operation status of power equipment and are widely applied in equipment quality inspection and fault ***-sensing technology can sense the change in surface light intensity caused by object vibration and provide a visual description of vibration *** on the analysis of the principle underlying the transformation of vibration behavior into event flow data by an event sensor,this paper proposes an algorithm to reconstruct event flow data into a relationship correlating vibration displacement and time to extract the amplitude-frequency characteristics of the vibration signal.A vibration measurement test platform is constructed,and feasibility and effectiveness tests are performed for the vibration motor and other power *** results show that event-sensing technology can effectively perceive the surface vibration behavior of power and provide a wide dynamic ***,the vibration measurement and visualization algorithm for power equipment constructed using this technology offers high measurement accuracy and *** results of this study provide a new noncontact and visual method for locating vibrations and performing amplitude-frequency analysis on power equipment.

关键词： Power equipment Event sensing Non contact measurement Graphic display Feasibility

An mmWave Dual-Band Integrated Substrate Gap Waveguide Single Cavity Filter with Frequency Selectivity

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China Communications 2024年第1期21卷 188-199页

作者： Qiuhua lin Dongya shen lihui Wang Zhiyong luo School of Electronics and Communication Engineering Sun Yat-sen UniversityShenzhen 518107China School of Information Science and Engineering Yunnan UniversityKunming 650091China Pengcheng laboratory Shenzhen 518107China shenzhen Key laboratory of Navigation and Communication Integration Shenzhen 518107China

A novel dual-band ISGW cavity filter with enhanced frequency selectivity is proposed in this paper by utilizing a multi-mode coupling *** cavity is designed to control the number of modes,and then the ports are determined by analyzing the coupling relationship between these selected *** synthesizing the coupling matrix of the filter,a nonresonating node(NRN)structure is introduced to flexibly tune the frequency of modes,which gets a dualband and quad-band filtering response from a tri-band filter no the ***,a frequency selective surface(FSS)has been newly designed as the upper surface of the cavity,which significantly improves the bad out-of-band suppression and frequency selectivity that often exists in most traditional cavity filter designs and *** results show that its two center frequencies are f01=27.50 GHz and f02=32.92GHz,*** with the dual-band filter that there is no the FSS metasurface,the out-of-band suppression level is improved from measured 5 dB to18 dB,and its finite transmission zero(FTZ)numbers is increased from measured 1 to 4 between the two designed *** with the tri-band and quadband filter,its passband bandwidth is expanded from measured 1.17%,1.14%,and 1.13% or 1.31%,1.50%,0.56%,and 0.57% to 1.71% and 1.87%.In addition,the filter has compact,small,and lightweight characteristics.

关键词： coupling topology frequency selectivity non-resonating node(NRN) out-of-band suppression single ISGW cavity filter

A Certified Cubic B-Spline Interpolation Method with Tangential Direction Constraints

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Journal of Systems Science & Complexity 2024年第3期37卷 1271-1294页

作者： HE Shitao shen liyong WU Qin yUAN Chunming School of Mathematical Sciences University of Chinese Academy of SciencesBeijing 100049China KlMM Academy of Mathematics and Systems ScienceChinese Academy of SciencesBeijing 100190China

Curve interpolation with B-spline is widely used in various areas. This problem is classic and recently raised in application scenario with new requirements such as path planning following the tangential vector field under certified error in CNC machining. This paper proposes an algorithm framework to solve Hausdorff distance certified cubic B-spline interpolation problem with or without tangential direction constraints. The algorithm has two stages: The first stage is to find the initial cubic B-spine fitting curve which satisfies the Hausdorff distance constraint;the second stage is to set up and solve the optimization models with certain constraints. Especially, the sufficient conditions of the global Hausdorff distance control for any error bound are discussed, which can be expressed as a series of linear and quadratic constraints. A simple numerical algorithm to compute the Hausdorff distance between a polyline and its B-spline interpolation curve is proposed to reduce our *** results are presented to show the advantages of the proposed algorithms.

关键词： Cubic B-spline Hausdorff distance interpolation tangential direction

yangtze River Delta Aerosol liquid water in PM_(2.5)and its roles in secondary aerosol formation at a regional site of yangtze River Delta

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Journal of Environmental Sciences 2024年第4期138卷 684-696页

作者： Ruifang Shi Fei Zhang yemin shen Jiasi shen Bingye Xu Binyu Kuang Zhengning Xu lingling Jin Qian Tang Xudong Tian Zhibin Wang College of Environmental and Resource Sciences Zhejiang Provincial Key Laboratory of Organic Pollution Process and ControlZhejiang UniversityHangzhou 310058China ZJU-Hangzhou Global Scientific and Technological Innovation Center Zhejiang UniversityHangzhou 311215China Zhejiang Ecological and Environmental Monitoring Center Hangzhou 310012China

Aerosol liquid water content(AlWC)plays an important role in secondary aerosol *** this study,a whole year field campaign was conducted at Shanxi in north Zhejiang Province during *** estimated by ISORROPIA-Ⅱ was then investigated to explore its characteristics and relationship with secondary *** exhibited a highest value in spring(66.38μg/m^(3)),followed by winter(45.08μg/m^(3)),summer(41.64μg/m^(3)),and autumn(35.01μg/m^(3)),*** was supposed that the secondary inorganic aerosols(SIA)were facilitated under higher AlWC conditions(RH>80%),while the secondary organic species tended to form under lower AlWC *** RH(>80%)promoted the NO_(3)^(-)formation via gas-particle partitioning,while SO_(4)^(2-)was generated at a relative lower RH(>50%).The AlWC was more sensitive to NO_(3)^(-)(R=0.94)than SO_(4)^(2-)(R=0.90).Thus,the self-amplifying processes between the AlWC and SIA enhanced the particle mass *** sensitivity of AlWC and OX(NO_(2)+O_(3))to secondary organic carbon(SOC)varied in different seasons at Shanxi,more sensitive to aqueous-phase reactions(daytime R=0.84;nighttime R=0.54)than photochemical oxidation(daytime R=0.23;nighttime R=0.41)in wintertime with a high level of OX(daytime:130-140μg/m^(3);nighttime:100-140μg/m^(3)).The self-amplifying process of AlWC and SIA and the aqueous-phase formation of SOC will enhance aerosol formation,contributing to air pollution and reduction of visibility.

关键词： Aerosol liquid water content Nitrate Sulfate Secondary organic compounds Aqueous-phase reaction

Feedback of Efficient Shock Acceleration on Magnetic-field Structure Inside young Type Ia Supernova Remnants

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Research in Astronomy and Astrophysics 2024年第6期24卷 234-244页

作者： Jun-yu shen Bi-Wen Bao li Zhang Department of Astronomy Key Laboratory of Astroparticle Physics of Yunnan ProvinceYunnan UniversityKunming 650091China Key laboratory of Statistical Modeling and Data Analysis of yunnan Province Yunnan UniversityKunming 650091China

Using an effective adiabatic index γ_(eff) to mimic the feedback of efficient shock acceleration,we simulate the temporal evolution of a young type Ia supernova remnant (SNR) with two different background magnetic field(BMF) topologies:a uniform and a turbulent *** density distribution and magnetic-field characteristics of our benchmark SNR are studied with two-dimensional cylindrical magnetohydrodynamic *** γ_(eff)is considered,we find that:(1) the two-shock structure shrinks and the downstream magnetic-field orientation is dominated by the Rayleigh–Taylor instability structures;(2) there exists more quasi-radial magnetic fields inside the shocked region;and (3) inside the intershock region,both the quasi-radial magnetic energy density and the total magnetic energy density are enhanced:in the radial direction,with γ_(eff)=1.1,they are amplified about 10–26 times more than those with γ_(eff)=5/*** in the angular direction,the total magnetic energy densities could be amplified about 350 times more than those with γ_(eff)=5/3,and there are more grid cells within the intershock region where the magnetic energy density is amplified by a factor greater than 100.

关键词： methods:numerical ISM:magnetic fields ISM:supernova remnants magnetohydrodynamics(MHD)

Utility and Application of a Versatile Analytical Method for MMF Calculation in AC Machines

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CES Transactions on Electrical Machines and Systems 2024年第1期8卷 22-31页

作者： Ze-Zheng Wu Robert Nilssen Jian-Xin shen IEEE the College of Electrical Engineering Zhejiang UniversityHangzhou 310027China the Department of Electric Energy Norwegian University of Science and TechnologyTrondheimNorwayand also affiliated with the College of Electrical EngineeringZhejiang UniversityHangzhou 310027China

A versatile analytical method(VAM) for calculating the harmonic components of the magnetomotive force(MMF) generated by diverse armature windings in AC machines has been proposed, and the versatility of this method has been established in early literature. However, its practical applications and significance in advancing the analysis of AC machines need further elaboration. This paper aims to complement VAM by augmenting its theory, offering additional insights into its conclusions, as well as demonstrating its utility in assessing armature windings and its application of calculating torque for permanent magnet synchronous machines(PMSM). This work contributes to advancing the analysis of AC machines and underscores the potential for improved design and performance optimization.

关键词： AC machine Analytical method Harmonic analysis MMF Magnetic field Torque calculation

Data-Driven learning Control Algorithms for Unachievable Tracking Problems

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IEEE/CAA Journal of Automatica Sinica 2024年第1期11卷 205-218页

作者： Zeyi Zhang Hao Jiang Dong shen Samer S.Saab the School of Mathematics Renmin University of ChinaBeijing 100872China IEEE the School of Engineering Lebanese American UniversityByblos 2038Lebanon

For unachievable tracking problems, where the system output cannot precisely track a given reference, achieving the best possible approximation for the reference trajectory becomes the objective. This study aims to investigate solutions using the Ptype learning control scheme. Initially, we demonstrate the necessity of gradient information for achieving the best ***, we propose an input-output-driven learning gain design to handle the imprecise gradients of a class of uncertain systems. However, it is discovered that the desired performance may not be attainable when faced with incomplete *** address this issue, an extended iterative learning control scheme is introduced. In this scheme, the tracking errors are modified through output data sampling, which incorporates lowmemory footprints and offers flexibility in learning gain *** input sequence is shown to converge towards the desired input, resulting in an output that is closest to the given reference in the least square sense. Numerical simulations are provided to validate the theoretical findings.

关键词： Data-driven algorithms incomplete information iterative learning control gradient information unachievable problems