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Residence time distribution of wood chips in a semi-industrial multiple hearth furnace using RFID tracers Author links open overlay panel

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Particuology 2024年第8期91卷 268-279页

作者： Elie Lacombe Muriel marchand capucine Dupont Denis maréchal Thierry Melkior Univ Grenoble Alpes CEALITENDTCHLaboratoire Réacteurs et ProcédésF-38000GrenobleFrance IHE Delft Department of Water Supply Sanitation and Environmental EngineeringDelftthe Netherlands John cockerill SeraingBelgium

In continuous biomass torrefaction plants,the products'yields,composition and homogeneity highly depend on the residence time of particles.A characterization of particle residence time distribution(RTD)was therefore carried out in an industrial-scale multiple hearth furnace on poplar wood chips using radio frequency identification *** effects of operating conditions,namely,mass flow rate of biomass,shaft speed of the rabbling system and interdental length on the RTD were *** increase of shaft speed and mass flow rate reduces particles’mean residence *** the length between two successive teeth also increases the bed *** biomass accumulation(also called“bulldozing”)was observed during several *** phenomenon is favored by a high mass flow rate of resources,a small interdental length between the teeth and a low shaft *** measurements were compared to the axial dispersion *** all tests,the Peclet number is ranging between 20 and 62,indicating that the multiple hearth furnace cannot be modelled as an ideal plug flow reactor.

关键词： Biomass Multiple hearth furnace Residence time distribution RFID

calibration of the DEM sliding friction and rolling friction parameters of a cohesionless bulk material

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Particuology 2024年第9期92卷 126-139页

作者： Jonatan marín Pérez Tugrul comlekci Yevgen Gorash Donald MacKenzie University of Strathclyde 75 Montrose StreetG11XJGlasgowUnited Kingdom

The discrete element method(DEM)has become a valuable tool for understanding the mechanical behaviour of granular assemblies,however,the accuracy of the DEM simulations depends on several interaction parameters such as the sliding friction and rolling friction ***,these parameters are estimated using bulk calibration approach(BcA)where the draw down test has been suggested as an effective way to approach these *** test provides up to four bulk criteria,the angle of repose,shear angle,mass flow rate and the mass loss which are used to narrow down the possible ***,there is still more research needed around it to fully understand how this methodology *** experimental and numerical study was carried out using the draw down test to assess the influence of different mass flow rates and particle shapes on DEM parameters for a cohesionless bulk *** is concluded that use of multi-sphere particles and three aperture sizes in the draw down test to calibrate the sliding and rolling friction parameters of a cohesionless bulk material can converge to a small feasible region in which a single combination of the friction coefficients can be *** calibrated sliding and rolling friction coefficients were validated using multi-sphere particles,where the maximum deviation was 5.9%from the experimental values.

关键词： Discrete element method calibration Draw down Sliding friction Rolling friction Particle shape

Dynamic Response Impact of Vehicle Braking on Simply Supported Beam Bridges with corrugated Steel Webs Based on Vehicle-Bridge coupled Vibration Analysis

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computer Modeling in Engineering & Sciences 2024年第6期139卷 3467-3493页

作者： Yan Wang Siwen Li na Wei School of civil Engineering Zhengzhou UniversityZhengzhou450001China

A novel approach for analyzing coupled vibrations between vehicles and bridges is presented,taking into account spatiotemporal effects and mechanical phenomena resulting fromvehicle *** modeling and solution of bridge vibrations induced by vehicle deceleration are realized using this *** method’s validity and reliability are substantiated through numerical examples.A simply supported beam bridge with a corrugated steel web is taken as an example and the effects of parameters such as the initial vehicle speed,braking acceleration,braking location,and road surface roughness on the mid-span displacement and impact factor of the bridge are *** results show that vehicle braking significantly amplifies mid-span displacement and impact factor responses in comparison to uniform vehicular motion across the ***,the influence of wheelto-bridge friction forces is of particular significance and cannot be *** the vehicle initiates braking near the middle of the span,both the mid-span displacement and impact factor of the bridge exhibit substantial increases,further escalating with higher braking *** favorable road surface conditions,the midspan displacement and the impact factor during vehicle braking may exceed the design values stipulated by *** is important to note that road surface roughness exerts a more pronounced effect on the impact factor of the bridge in comparison to the effects of vehicle braking.

关键词： corrugated steel web girder bridges simply supported beam bridges vehicle-bridge coupled vibration braking impact factor

A New Encrypted Traffic Identification Model Based on VAE-LSTM-DRN

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computers, Materials & continua 2024年第1期78卷 569-588页

作者： Haizhen Wang Jinying Yan na Jia college of computer and control Engineering Qiqihar UniversityQiqihar161006China Heilongjiang Key Laboratory of Big Data Network Security Detection and Analysis Qiqihar UniversityQiqiharChina

Encrypted traffic identification pertains to the precise acquisition and categorization of data from traffic datasets containing imbalanced and obscured *** extraction of encrypted traffic attributes and their subsequent identification presents a formidable *** existing models have predominantly relied on direct extraction of encrypted traffic data from imbalanced datasets,with the dataset’s imbalance significantly affecting the model’s *** the present study,a new model,referred to as UD-VLD(Unbalanced Dataset-VAE-LSTM-DRN),was proposed to address above *** proposed model is an encrypted traffic identification model for handling unbalanced *** encoder of the variational autoencoder(VAE)is combined with the decoder and Long-short term Memory(LSTM)in UD-VLD model to realize the data enhancement processing of the original unbalanced *** enhanced data is processed by transforming the deep residual network(DRN)to address neural network gradient-related ***,the data is classified and *** UD-VLD model integrates the related techniques of deep learning into the encrypted traffic recognition technique,thereby solving the processing problem for unbalanced *** UD-VLD model was tested using the publicly available Tor dataset and VPN *** UD-VLD model is evaluated against other comparative models in terms of accuracy,loss rate,precision,recall,F1-score,total time,and ROc *** results reveal that the UD-VLD model exhibits better performance in both binary and multi classification,being higher than other encrypted traffic recognition models that exist for unbalanced ***,the evaluation performance indicates that the UD-VLD model effectivelymitigates the impact of unbalanced data on traffic *** can serve as a novel solution for encrypted traffic identification.

关键词： Data enhancement LSTM deep residual network VAE

Grasslands Response to Livestock Grazing Intensity in the Austral Pampas(Argentina):Testing the Intermediate Disturbance Hypothesis

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Phyton-International Journal of Experimental Botany 2024年第8期93卷 2037-2050页

作者： Ana Elena de Villalobos maría Andrea Long Grupo de Investigación en Ecosistemas de Pastizal(GIEP) CERZOSCONICETBahía Blanca8000Argentina Departamento de Biología Bioquímica y FarmaciaUniversidad Nacional del SurBahía Blanca8000Argentina

Livestock grazing has a significant impact on natural grasslands,with approximately one-third of the world’s land area dedicated to this *** 20%of global grasslands are highly degraded due to overgrazing,affecting their productivity and conservation *** practices are required to ensure sustainable livestock production that supports *** Intermediate Disturbance Hypothesis(IDH)suggests that environments with moderate levels of disturbance exhibit a higher species *** grazing can reduce the dominance of certain species,thereby enhancing plant ***,concerns arise regarding the increase of exotic and unpalatable species under moderate grazing levels,complicating grassland conservation *** impact of livestock grazing on the functional structure of grasslands depends on factors such as grazing intensity,livestock species,and environmental *** in grazing intensity may increase specific and functional diversity under moderate grazing,potentially masking the presence of invasive exotic *** the Austral Pampas(Pampean phytogeographic province,Buenos Aires,Argentina),grasslands face various pressures from domestic livestock grazing that endanger their integrity if not properly ***,our study aims to investigate potential differences in species richness and diversity,functional diversity,exotic plant abundance,and the number and distribution of plant functional groups across varying grazing *** IDH is utilized as a tool to regulate livestock pressure for grassland *** and functional diversity indices were used to assess the impact of grazing on grassland *** grazing increased species and functional diversity,while intensively grazed or ungrazed areas showed reduced *** presence influenced the balance between native and exotic plants,with ungrazed areas having higher native plant abundance and grazed areas exhibiti

关键词： natural grasslands grazing effects disturbance specific and functional diversity

Survey on Fake Information Generation,Dissemination and Detection

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chinese Journal of Electronics 2024年第3期33卷 573-583页

作者： Wanqiu cUI Dawei WANG na HAN School of national Security People's Public Security University of China Big Data center of The Ministry of Public Security

The current booming development of the Internet has put the public in an era of information overload,in which false information is mixed and spread *** phenomenon has seriously disturbed the social network ***,a substantial amount of research is beginning to be devoted to the effective management of fake *** analyze the abnormal characteristics of fake information from its mechanism of generation and *** view of different exceptional features,we systematically sort out and evaluate the existing studies on false content *** commonly used public datasets,metrics,and performance are categorized and compared,hoping to provide a basis and guidance for related *** study found that the current active social platforms show different *** future direction should point to mining platform features of multi-domain sources,multi-data forms,and multi-language heterogeneity to provide more valuable clues for fake information.

关键词： Fake information Abnormal characteristics Detection methods Public datasets

The Influence of Different Solar System Planetary Ephemerides on Pulsar Timing

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Research in Astronomy and Astrophysics 2024年第8期24卷 85-99页

作者： Jian-Peng Dai Wei Han na Wang School of Physical Science and Technology Xinjiang UniversityUrumqi 830046China Xinjiang Astronomical Observatory Chinese Academy of SciencesUrumqi 830011China University of chinese Academy of Sciences Beijing 100049China Xinjiang Key Laboratory of Radio Astrophysics Urumqi 830011China

Pulsar timing offers a comprehensive avenue for exploring diverse topics in physics and *** solar system planetary ephemeris is crucial for pulsar timing as it provides the positions and velocities of solar system planets including the ***,it is inevitable that inherent inconsistencies exist in these *** between various ephemerides can significantly impact pulsar timing and parameter ***,pulsar timing highly depends on the JPL DE ephemeris,for instance,the Pulsar Timing Array data analysis predominantly utilizes *** this study,we examine inconsistencies across various ephemeris series,including JPL DE,EPM,and ***,discrepancies emerge particularly between the current ephemeris DE436 and the earliest released ephemeris DE200,as well as the most recent ephemerides,e.g.,DE440,INPOP21A,and *** detailed analysis of the effects of ephemeris on geometric correction procedures for the conversion of measured topocentric times of arrival is presented in this *** researches reveal that variations in the Roemer delays across different ephemerides lead to distinct *** timing residuals and the fact that these discrepancies can be readily incorporated into the subsequent pulsar parameters,leading to inconsistent fitting estimates,suggest that the influence of errors in the ephemeris on the timing process might currently be underappreciated.

关键词： (stars)pulsars general-Planetary Systems-time-ephemerides

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

Spatiotemporal characteristics of cultivated land use eco-efficiency and its influencing factors in china from 2000 to 2020

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Journal of Arid Land 2024年第3期16卷 396-414页

作者： LI Shaoting MU na REN Yanjun Thomas GLAUBEN college of Economics and Management Northwest A&F UniversityYangling 712100China Sino-German center for Agricultural and Food Economics Northwest A&F UniversityYangling 712100China Leibniz Institute of Agricultural Development in Transition Economies(IAMO) Halle 06120Germany

Improving cultivated land use eco-efficiency(cLUE)can effectively promote agricultural sustainability,particularly in developing countries where cLUE is generally *** study used provincial-level data from china to evaluate the spatiotemporal evolution of cLUE from 2000 to 2020 and identified the influencing factors of cLUE by using a panel Tobit *** addition,given the undesirable outputs of agricultural production,we incorporated carbon emissions and nonpoint source pollution into the global benchmark-undesirable output-super efficiency-slacks-based measure(GB-US-SBM)model,which combines global benchmark technology,undesirable output,super efficiency,and slacks-based *** results indicated that there was an upward trend in cLUE in china from 2000 to 2020,with an increase rate of 2.62%.The temporal evolution of cLUE in china could be classified into three distinct stages:a period of fluctuating decrease(2000-2007),a phase of gradual increase(2008-2014),and a period of rapid growth(2015-2020).The major grain-producing areas(MPAs)had a lower cLUE than their counterparts,namely,non-major grain-production areas(non-MPAs).The spatial agglomeration effect followed a northeast-southwest strip distribution;and the movement path of barycentre revealed a"P"shape,with Luoyang city,Henan Province,as the *** terms of influencing factors of cLUE,investment in science and technology played the most vital role in improving cLUE,while irrigation index had the most negative *** should be noted that these two influencing factors had different impacts on MPAs and ***,relevant departments should formulate policies to enhance the level of science and technology,improve irrigation condition,and promote sustainable utilization of cultivated land.

关键词： cultivated land use eco-efficiency(cLUE) slacks-based measure(SBM)model barycentre model standard deviation ellipse(SDE) panel Tobit model carbon emissions nonpoint source pollution