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Joint position optimization,user association,and resource allocation for load balancing in UAV-assisted wireless networks

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Digital Communications and Networks 2024年第1期10卷 25-37页

作者： Daosen Zhai Huan Li xiao Tang Ruonan Zhang Haotong cao School of Electronics and Information Northwestern Polytechnical UniversityXian710072China State Key Laboratory of Integrated Services Networks Xidian UniversityXian710071China Department of Computing Hong Kong Polytechnic UniversityHong Kong SARChina

Unbalanced traffic distribution in cellular networks results in congestion and degrades spectrum *** tackle this problem,we propose an Unmanned Aerial Vehicle(UAV)-assisted wireless network in which the UAV acts as an aerial relay to divert some traffic from the overloaded cell to its adjacent underloaded *** fully exploit its potential,we jointly optimize the UAV position,user association,spectrum allocation,and power allocation to maximize the sum-log-rate of all users in two adjacent *** tackle the complicated joint optimization problem,we first design a genetic-based algorithm to optimize the UAV ***,we simplify the problem by theoretical analysis and devise a low-complexity algorithm according to the branch-and-bound method,so as to obtain the optimal user association and spectrum allocation *** further propose an iterative power allocation algorithm based on the sequential convex approximation *** simulation results indicate that the proposed UAV-assisted wireless network is superior to the terrestrial network in both utility and throughput,and the proposed algorithms can substantially improve the network performance in comparison with the other schemes.

关键词： Load balance Unmanned aerial vehicle Userassociation Resource management

Adsorption limitation investigation on olefins for Cu–BTC

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Friction 2024年第4期12卷 606-617页

作者： xiao YANG Yunbo WANG Weihua cao Ruizheng JIANG Guoxin XIE Yuying cao xiaowen QI School of Mechanical Engineering Yanshan UniversityQinhuangdao 066004China Key Laboratory of Self-Lubricating Spherical Plain Bearing Technology of Hebei Province Yanshan UniversityQinhuangdao 066004China State Key Laboratory of Tribology in Advanced Equipment Department of Mechanical EngineeringTsinghua UniversityBeijing 100084China Aviation Key Laboratory of Science and Technology on Generic Technology of Self-Lubricating Spherical Plain Bearing Yanshan UniversityQinhuangdao 066004China

To utilize Cu-benzene-1,3,5-tricarboxylate(Cu-BTC)adsorbed lubricant oils in the self-lubricating field,the adsorption properties of Cu-BTC on different 1-olefins must be *** this work,1-hexene,1-octene,1-nonene,1-decene,1-undecene,and 1-dodecene were studied by the Monte Carlo method and *** adsorption limit of Cu-BTC for n-olefins was determined as 1-undecene by the adsorption *** suggested a limit for even straight-chain molecules to the adsorption of *** maximum ratio of the olefin length of the largest pore diameter(L/D)of Cu-BTC was approximately ***,theoretical calculations(radial distribution function(RDF))and experiments(infrared(IR)spectra)confirmed the interaction of n-olefin adsorbates and the Cu-BTC framework occurred between the-CH=of olefins and the Cu and O atoms of the Cu-BTC *** work adds to the understanding and investigation of the adsorption of liquid lubricants using Cu-BTC as a metal-organic framework(MOF).

关键词： metal-organic framework(MOF) Cu-benzene-1,3,5-tricarboxylate(Cu-BTC) Monte Carlo method adsorption properties 1-olefins

Metabolomic Analysis in Saliva and Different Brain Regions of Older Mice with Postoperative Delirium Behaviors

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Biomedical and Environmental Sciences 2024年第2期37卷 133-145页

作者： LIU xiao cao Ying LIN xiao Wan GAO Dan Yang MIAO Hui Hui LI Tian Zuo Department of Anesthesiology Beijing Shijitan HospitalCapital Medical UniversityBeijing 100038China

Objective Postoperative delirium(POD)has become a critical challenge with severe consequences and increased incidences as the global population ***,the underlying mechanism is yet *** study aimed to explore the changes in metabolites in three specific brain regions and saliva of older mice with postoperative delirium behavior and to identify potential non-invasive *** Eighteen-month-old male C57/BL6 mice were randomly assigned to the anesthesia/surgery or control *** tests were conducted 24 h before surgery and 6,9,and 24 h after *** C3(C3)and S100 calcium-binding protein B protein(S100beta)levels were measured in the hippocampus,and a metabolomics analysis was performed on saliva,hippocampus,cortex,and amygdala *** In total,43,33,38,and 14 differential metabolites were detected in the saliva,hippocampus,cortex,and amygdala,respectively.“Pyruvate”“alpha-linolenic acid”and“2-oleoyl-1-palmitoy-snglycero-3-phosphocholine”are enriched in one common pathway and may be potential non-invasive biomarkers for *** changes were observed in the three brain regions,with the upregulation of 1-methylhistidine and downregulation of *** Dysfunctions in energy metabolism,oxidative stress,and neurotransmitter dysregulation are implicated in the development of *** identification of changes in the level of salivary metabolite biomarkers could aid in the development of noninvasive diagnostic methods for POD.

关键词： Metabolomic Postoperative delirium(POD) Mechanism Biological marker

Fast spreading of surface ozone in both temporal and spatial scale in Pearl River Delta

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Journal of Environmental Sciences 2024年第3期137卷 540-552页

作者： Tianhui cao Haichao Wang Lei Li xiao Lu Yiming Liu Shaojia Fan School of Atmospheric Sciences Sun Yat-sen University and Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai)Zhuhai 519082China Guangdong Provincial Observation and Research Station for Climate Environment and Air Quality Change in the Pearl River Estuary Key Laboratory of Tropical Atmosphere-Ocean SystemMinistry of EducationZhuhai 519082China

Surface ozone(O_(3))is a major air pollutant and draw increasing attention in the Pearl River Delta(PRD),***,we characterize the spatial-temporal variability of ozone based on a dataset obtained from 57 national monitoring sites during *** results show that:(1)the seasonal difference of ozone distribution in the inland and coastal areas was significant,which was largely affected by the wind pattern reversals related to the East Asian monsoon,and local ozone production and destruction;(2)the daily maximum 8hr average(MDA8 O_(3))showed an overall upward trend by 1.11 ppbv/*** the trends in the nine cities varied differently by ranging from-0.12 to 2.51 ppbv/*** hot spots of ozone were spreading to southwestern areas from the central areas since *** ozone is becoming a year-round air pollution problem with the pollution season extending to winter and spring in PRD region.(3)at the central and southwestern PRD cities,the percentage of exceedance days from the continuous type(defined as≥3 days)was ***,the ozone concentration of continuous type was much higher than that of scattered exceedance type(<3 days).In addition,although the occurrence of continuous type starts to decline since2017,the total number of exceedance days during the continuous type is *** results indicate that it is more difficult to eliminate the continuous exceedance than the scatter pollution days and highlight the great challenge in mitigation of O_(3)pollution in these cities.

关键词： Surface ozone pollution Ozone trend Spatial and temporal variability Pearl River Delta Pollution mitigation

Detection Algorithm of Laboratory Personnel Irregularities Based on Improved YOLOv7

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Computers, Materials & Continua 2024年第2期78卷 2741-2765页

作者： Yongliang Yang Linghua Xu Maolin Luo xiao Wang Min cao School of Electrical Engineering Guizhou UniversityGuiyang550025China

Due to the complex environment of the university laboratory,personnel flow intensive,personnel irregular behavior is easy to cause security *** using mainstream detection algorithms suffers from low detection accuracy and slow ***,the current management of personnel behavior mainly relies on institutional constraints,education and training,on-site supervision,etc.,which is time-consuming and *** the above situation,this paper proposes an improved You Only Look Once version 7(YOLOv7)to achieve the purpose of quickly detecting irregular behaviors of laboratory personnel while ensuring high detection ***,to better capture the shape features of the target,deformable convolutional networks(DCN)is used in the backbone part of the model to replace the traditional convolution to improve the detection accuracy and ***,to enhance the extraction of important features and suppress useless features,this paper proposes a new convolutional block attention module_efficient channel attention(CBAM_E)for embedding the neck network to improve the model’s ability to extract features from complex ***,to reduce the influence of angle factor and bounding box regression accuracy,this paper proposes a newα-SCYLLA intersection over union(α-SIoU)instead of the complete intersection over union(CIoU),which improves the regression accuracy while increasing the convergence *** experiments on public and homemade datasets show that the improved algorithm outperforms the original algorithm in all evaluation indexes,with an increase of 2.92%in the precision rate,4.14%in the recall rate,0.0356 in the weighted harmonic mean,3.60%in the mAP@0.5 value,and a reduction in the number of parameters and *** with the mainstream algorithm,the improved algorithm has higher detection accuracy,faster convergence speed,and better actual recognition effect,indicating the effectiveness of the improved algorithm in this p

关键词： University laboratory personnel behavior YOLOv7 deformable convolutional networks attention module intersection over union

Challenges in Li-ion battery high-voltage technology and recent advances in high-voltage electrolytes

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Journal of Energy Chemistry 2024年第4期91卷 73-98页

作者： Jianguo Liu Baohui Li Jinghang cao xiao Xing Gan Cui Shandong Key Laboratory of Oil&Gas Storage and Transportation Safety College of Pipeline and Civil EngineeringChina University of Petroleum(East China)Qingdao 266580ShandongChina

The electrolyte directly contacts the essential parts of a lithium-ion battery,and as a result,the electrochemical properties of the electrolyte have a significant impact on the voltage platform,charge discharge capacity,energy density,service life,and rate discharge *** raising the voltage at the charge/discharge plateau,the energy density of the battery is ***,this causes transition metal dissolution,irreversible phase changes of the cathode active material,and parasitic electrolyte oxidation *** article presents an overview of these concerns to provide a clear explanation of the issues involved in the development of electrolytes for high-voltage lithium-ion ***,solidstate electrolytes enable various applications and will likely have an impact on the development of batteries with high energy *** is necessary to improve the high-voltage performance of electrolytes by creating solvents with high thermal stabilities and high voltage resistance and additives with superior film forming performance,multifunctional capabilities,and stable lithium *** offer suggestions for the future development of high-energy lithium-ion batteries,we conclude by offering our own opinions and insights on the current development of lithium-ion batteries.

关键词： Lithium-ion battery High voltage Electrolyte additive Solid electrolyte

Gates joint locally connected network for accurate and robust reconstruction in optical molecular tomography

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Journal of Innovative Optical Health Sciences 2024年第3期17卷 11-22页

作者： Minghua Zhao Yahui xiao Jiaqi Zhang Xin cao Lin Wang School of Computer Science and Engineering Xi’an University of TechnologyXi’anChina School of Information Science and Technology Northwest UniversityXi’an 710127China

Optical molecular tomography(OMT)is a potential pre-clinical molecular imaging technique with applications in a variety of biomedical areas,which can provide non-invasive quantitative three-dimensional(3D)information regarding tumor distribution in living *** construction of optical transmission models and the application of reconstruction algorithms in traditional model-based reconstruction processes have affected the reconstruction results,resulting in problems such as low accuracy,poor robustness,and long-time ***,a gates joint locally connected network(GLCN)method is proposed by establishing the mapping relationship between the inside source distribution and the photon density on surface directly,thus avoiding the extra time consumption caused by iteration and the reconstruction errors caused by model ***,gates module was composed of the concatenation and multiplication operators of three different *** was embedded into the network aiming at remembering input surface photon density over a period and allowing the network to capture neurons connected to the true source selectively by controlling three different *** evaluate the performance of the proposed method,numerical simulations were conducted,whose results demonstrated good performance in terms of reconstruction positioning accuracy and robustness.

关键词： Optical molecular tomography gates module positioning accuracy robustness

Atomic layer deposition in advanced display technologies:from photoluminescence to encapsulation

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International Journal of Extreme Manufacturing 2024年第2期6卷 65-82页

作者： Rong Chen Kun cao Yanwei Wen Fan Yang Jian Wang xiao Liu Bin Shan State Key Laboratory of Intelligent Manufacturing Equipment and Technology School of Mechanical Science and EngineeringHuazhong University of Science and TechnologyWuhan 430074HubeiPeople’s Republic of China State Key Laboratory of Materials Processing and Die&Mould Technology School of Materials Science and EngineeringHuazhong University of Science and TechnologyWuhan 430074HubeiPeople’s Republic of China

Driven by the growing demand for next-generation displays,the development of advanced luminescent materials with exceptional photoelectric properties is rapidly accelerating,with such materials including quantum dots and phosphors,***,the primary challenge preventing the practical application of these luminescent materials lies in meeting the required durability *** layer deposition(ALD)has,therefore,been employed to stabilize luminescent materials,and as a result,flexible display devices have been fabricated through material modification,surface and interface engineering,encapsulation,cross-scale manufacturing,and *** addition,the appropriate equipment has been developed for both spatial ALD and fluidized ALD to satisfy the low-cost,high-efficiency,and high-reliability manufacturing *** strategic approach establishes the groundwork for the development of ultra-stable luminescent materials,highly efficient light-emitting diodes(LEDs),and thin-film ***,this significantly enhances their potential applicability in LED illumination and backlighted displays,marking a notable advancement in the display industry.

关键词： atomic layer deposition display luminescent encapsulation

Factors Influencing the Spatial Variability of Air Temperature Urban Heat Island Intensity in Chinese Cities

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Advances in Atmospheric Sciences 2024年第5期41卷 817-829页

作者： Heng LYU Wei WANG Keer ZHANG Chang cao Wei xiao Xuhui LEE Key Laboratory of Meteorological Disaster Ministry of Education(KLME)/Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters(CIC-FEMD)/Key Laboratory of Ecosystem Carbon Source and SinkChina Meteorological Administration(ECSS-CMA)/Jiangsu Key Laboratory of Agricultural MeteorologyNanjing University of Information Science&TechnologyNanjing 210044China Key Laboratory of Urban Meteorology China Meteorological AdministrationBeijing 100089China School of the Environment Yale UniversityNew HavenCT 06511USA

Few studies have investigated the spatial patterns of the air temperature urban heat island(AUHI)and its controlling *** this study,the data generated by an urban climate model were used to investigate the spatial variations of the AUHI across China and the underlying climate and ecological drivers.A total of 355 urban clusters were *** performed an attribution analysis of the AUHI to elucidate the mechanisms underlying its *** results show that the midday AUHI is negatively correlated with climate wetness(humid:0.34 K;semi-humid:0.50 K;semi-arid:0.73 K).The annual mean midnight AUHI does not show discernible spatial patterns,but is generally stronger than the midday *** urban–rural difference in convection efficiency is the largest contributor to the midday AUHI in the humid(0.32±0.09 K)and the semi-arid(0.36±0.11 K)climate *** release of anthropogenic heat from urban land is the dominant contributor to the midnight AUHI in all three climate *** rural vegetation density is the most important driver of the daytime and nighttime AUHI spatial variations.A spatial covariance analysis revealed that this vegetation influence is manifested mainly through its regulation of heat storage in rural land.

关键词： air temperature urban heat island spatial variations biophysical drivers Chinese cities climate model