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土壤阻力连续测试设备研制

农业工程学报 2009年第2期25卷 67-71页

作者：赵新罗锡文 l.g.wells 华南农业大学南方农业机械与装备关键技术省部共建教育部重点实验室广州510642 美国肯塔基大学生物与农业工程系列克星敦40546

为解决目前点采样方法获取的土壤压实信息少和信息获取速度慢的不足,该文研制了可快速连续测量土壤阻力(水平方向)以反映土壤压实程度的测试系统。系统包括机械部分、传感器和信息采集3部分。测试系统由拖拉机牵引,工作时连续测试速度1 ... 详细信息

为解决目前点采样方法获取的土壤压实信息少和信息获取速度慢的不足,该文研制了可快速连续测量土壤阻力(水平方向)以反映土壤压实程度的测试系统。系统包括机械部分、传感器和信息采集3部分。测试系统由拖拉机牵引,工作时连续测试速度1 m/s,土壤阻力信息采样频率为300 Hz,采样数据处理后与gPS定位数据对应存储。实验室试验表明,系统平均测试精度达93.4%。田间试验显示,测试系统性能可靠稳定,具有连续快速获取土壤压实程度信息并反映土壤压实程度空间分布的能力。定义的土壤阻力指数TRI可以反映土壤的压实程度。

关键词：八角环传感器变深耕作土壤阻力土壤压实

Optimal Control of Service Rates of Discrete-Time(s,Q)Queueing-Inventory Systems with Finite Buffer

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Journal of Systems Science and Systems Engineering 2024年第3期33卷 261-280页

作者： l.Iniya B.Sivakumar g.Arivarignan School of Mathematics Madurai Kamaraj UniversityMaduraiTamilnaduIndia Department of Statistics Manonmaniam Sundaranar UniversityTirunelveliTamilnaduIndia

This article,we develop an optimal policy to control the service rate of a discrete time queueing-inventory system with finite buffer.The customers arrive according to a Bernoulli process and the service time for the customers are geometric.Whenever the buffer size attains its maximum,any arriving new customers are considered to be lost.The customers are served one by one according to FCFS rule and each customers request random number of items.The inventory is replenished according to a(s,Q)inventory policy with geometric lead time.The main objectives of this article are to determine the service rates to be employed at each slot so that the long run expected cost rate is minimized for fixed inventory level and fixed buffer size and to minimize the expected waiting time for a fixed inventory level and fixed buffer size.The problems are modelled as Markov decision problem.We establish the existence of a stationary policy and employ linear programming method to find the optimal service rates.We provide some numerical examples to illustrate the behaviour of the model.

关键词： Queueing-inventory system discrete time batch demand-Markov decision process

Semi-analytical investigation of heat transfer in a porous convective radiative moving longitudinal fin exposed to magnetic field in the presence of a shape-dependent trihybrid nanofluid

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Applied Mathematics and Mechanics(English Edition) 2024年第1期45卷 197-216页

作者： C.g.PAVITHRA B.J.gIREESHA M.l.KEERTHI Department of Pg Studies and Research in Mathematics Kuvempu UniversityShankaraghatta 577451India Department of Mathematics and Statistics M.S.Ramaiah University of Applied SciencesBengaluru 560058India

The thermal examination of a non-integer-ordered mobile fin with a magnetism in the presence of a trihybrid nanofluid(Fe_3O_4-Au-Zn-blood) is carried out. Three types of nanoparticles, each having a different shape, are considered. These shapes include spherical(Fe_3O_4), cylindrical(Au), and platelet(Zn) configurations. The combination approach is utilized to evaluate the physical and thermal characteristics of the trihybrid and hybrid nanofluids, excluding the thermal conductivity and dynamic viscosity. These two properties are inferred by means of the interpolation method based on the volume fraction of nanoparticles. The governing equation is transformed into a dimensionless form, and the Adomian decomposition Sumudu transform method(ADSTM) is adopted to solve the conundrum of a moving fin immersed in a trihybrid nanofluid. The obtained results agree well with those numerical simulation results, indicating that this research is reliable. The influence of diverse factors on the thermal overview for varying noninteger values of γ is analyzed and presented in graphical representations. Furthermore, the fluctuations in the heat transfer concerning the pertinent parameters are studied. The results show that the heat flux in the presence of the combination of spherical, cylindrical, and platelet nanoparticles is higher than that in the presence of the combination of only spherical and cylindrical nanoparticles. The temperature at the fin tip increases by 0.705 759% when the value of the Peclet number increases by 400%, while decreases by 11.825 13% when the value of the Hartman number increases by 400%.

关键词： convection radiation moving longitudinal fin Adomian decomposition Sumudu transform method(ADSTM) trihybrid nanofluid magnetic field

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土壤阻力连续测试系统农田试验研究

农机化研究 2012年第8期34卷 111-115页

土壤阻力连续测试系统可连续获取农田压实的土壤阻力信息。为研究土壤阻力连续测试系统测试土壤阻力指数(TRI)的适用性,安排了小区对比、大田对比和工作速度影响3个试验,进行了土壤阻力指数TRI值与土壤圆锥指数CI值对比分析。试验结果表... 详细信息

土壤阻力连续测试系统可连续获取农田压实的土壤阻力信息。为研究土壤阻力连续测试系统测试土壤阻力指数(TRI)的适用性,安排了小区对比、大田对比和工作速度影响3个试验,进行了土壤阻力指数TRI值与土壤圆锥指数CI值对比分析。试验结果表明:在表征农田土壤压实程度上,TRI值与CI值具有一致性,即利用土壤阻力连续测量系统测取的TRI数据可以反应农田土壤的压实程度;土壤阻力连续测量系统采样连续、数据信息量大和采样效率高,适合于大面积农田土壤信息快速采集,有利于变耕深耕作技术的开展;在保证系统高效、安全和测试数据稳定的前提下,试验结果显示测试系统较理想的工作速度是1.0m/s。

关键词：土壤阻力测试信息采集土壤阻力指数土壤圆锥指数

Digital Social Connectedness as a lifeline for Older People: Use and Non-use of VinclesBCN During the Pandemic

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International Journal of Disaster Risk Science 2024年第2期15卷 251-264页

作者： Israel Rodríguez-giralt Daniel lópez-gómez Roser Beneito-Montagut CareNet IN3 Universitat Oberta de Catalunya School of Social Sciences Cardiff University

This article presents the results of a study that evaluated VinclesBCN during COVID-19. This digital-based public social service aims to prevent loneliness and isolation in +65-year-old adults living in Barcelona. Through service user(N = 12) and professional(N = 6) interviews and a questionnaire with service users(N = 255), we demonstrate the pivotal role of digital connectedness in transforming VinclesBCN into a lifeline during the pandemic. The analysis revealed the importance of sociability, social support, and, especially, entertainment in coping with pandemic fatigue and facilitating social connectivity and support among users. Users engaged in activities such as sharing images, songs, memes, and daily greetings to provide proximity, sociability, and care among users, whether they belonged to preexisting groups or were newly introduced to the platform. It also facilitated the identification of individuals who needed companionship, comfort, or more specialized support. The findings emphasize the significance of entertainment as a resilience-building strategy during times of uncertainty. Despite the positive impact, not all users equally used the platform. Non-use was strongly associated with being a woman, having a low educational level, having preexisting social relationships, less time of enrolment in the platform, as well as a high perception of loneliness, poor self-reported health, and low mood. The article underscores the need for further research into older adults' digital engagement during crises, its role in building resilience, and advocating for inclusive digital interventions that take into account diverse older adults' needs and experiences in crisis contexts.

关键词： Barcelona COVID-19 pandemic Digital social connectedness Entertainment Older adult resilience Public digital service

In vitro engineered models of neurodegenerative diseases

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BIOCEll 2024年第1期48卷 79-96页

作者： ZEHRA gÜl MORÇIMEN ŞEYMA TAŞDEMIR AYlIN ŞENDEMIR Bioengineering Department Graduate School of Natural and Applied SciencesEge UniversityIzmir35040Türkiye Bioengineering Department Faculty of Engineering and Natural ScienceCelal Bayar UniversityManisa45110Türkiye Bioengineering Department Ege UniversityIzmir35040Türkiye Department of Biomedical Technologies Graduate School of Natural and Applied SciencesEge UniversityIzmir35040Türkiye

Neurodegeneration is a catastrophic process that develops progressive damage leading to functional andstructural loss of the cells of the nervous system and is among the biggest unavoidable problems of our age.Animalmodels do not reflect the pathophysiology observed in humans due to distinct differences between the neuralpathways,gene expression patterns,neuronal plasticity,and other disease-related mechanisms in animals andhumans.Classical in vitro cell culture models are also not sufficient for pre-clinical drug testing in reflecting thecomplex pathophysiology of neurodegenerative diseases.Today,modern,engineered techniques are applied to developmulticellular,intricate in vitro models and to create the closest microenvironment simulating biological,biochemical,and mechanical characteristics of the in vivo degenerating tissue.In THIS review,the capabilities and shortcomings ofscaffold-based and scaffold-free techniques,organoids,and microfluidic models that best reflect neurodegeneration invitro in the biomimetic framework are discussed.

关键词： Neurodegenerative diseases In vitro models Scaffolds Organoids Microfluidic devices

New immune regulators of sciatic nerve regeneration?lessons from the neighborhood

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Neural Regeneration Research 2024年第4期19卷 705-706页

作者： Andrél.Bombeiro Rodrigo g.Q.Fernandes Julie C.Ribot Instituto de Medicina Molecular João lobo Antunes Faculdade de MedicinaUniversidade de LisboaLisbonPortugal

For decades,the immune system has been associated with host protection against infectious pathogens or tumors,while also contributing to autoimmunity.Notwithstanding,this paradigm is now changing,with recent studies highlighting novel roles for immune mediators in the maintenance of steady-state tissue homeostasis.In this perspective,we review some of the latest findings featuring immune modulators of the nervous system pathophysiology,with a special focus on interleukin(Il)-17.

关键词： homeostasis neighborhood finding

Exploring unconventional attributes of red blood cells and their potential applications in biomedicine

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Protein & Cell 2024年第5期15卷 315-330页

作者： Alkmini T.Anastasiadi Vasiliki-Zoi Arvaniti Krystalyn E.Hudson Anastasios g.Kriebardis Constantinos Stathopoulos Angelo D’Alessandro Steven l.Spitalnik Vassilis l.Tzounakas Department of Biochemistry School of MedicineUniversity of Patras26504 PatrasGreece Department of Pathology and Cell Biology Columbia University Irving Medical CenterNew York CityNY 10032USA laboratory of Reliability and Quality Control in laboratory Hematology(HemQcR) Department of Biomedical SciencesSchool of Health&Caring SciencesUniversity of West Attica(UniWA)12243 EgaleoGreece Department of Biochemistry and Molecular genetics University of Colorado Anschutz Medical Campus13001 AuroraCOUSA Present address:Institute for Fundamental Biomedical Research(IFBR) Biomedical Sciences Research Center“Alexander Fleming”Vari11527 AthensGreece

We need to talk about red blood cells.Eukaryotic cells are defined as cells containing distinct nuclei and other membranous organelles.However,red blood cells(RBCs)lack a nucleus and organelles—perhaps to limit the generation of reactive oxygen species(Zhang et al.,2011)—and are filled with hemoglobin(Hb).This oxygen carrier is limited to the cytosol by the cell membrane and cytoskeleton,which maintain cellular integrity and deformability as RBCs pass through narrow capillaries(gratzer,1994)to perform their primary function of gas exchange.

关键词： al. membranous maintain

Exact solutions for magnetohydrodynamic nanofluids flow and heat transfer over a permeable axisymmetric radially stretching/shrinking sheet

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Chinese Physics B 2024年第2期33卷 108-114页

作者： U.S.Mahabaleshwar g.P.Vanitha l.M.Pérez Emad H.Aly I.Pop Department of Studies in Mathematics Davangere UniversityShivagangothriDavangereIndia Departamento de F´ısica FACIUniversidad de Tarapac´aCasilla 7DAricaChile Department of Mathematics Faculty of EducationAin Shams UniversityRoxyCairoEgypt Department of Mathematics Babes-Bolyai University400084 Cluj-NapocaRomania

We report on the magnetohydrodynamic impact on the axisymmetric flow of Al_(2)O_(3)/Cu nanoparticles suspended in H_(2)O past a stretched/shrinked sheet.With the use of partial differential equations and the corresponding thermophysical characteristics of nanoparticles,the physical flow process is illustrated.The resultant nonlinear system of partial differential equations is converted into a system of ordinary differential equations using the suitable similarity transformations.The transformed differential equations are solved analytically.Impacts of the magnetic parameter,solid volume fraction and stretching/shrinking parameter on momentum and temperature distribution have been analyzed and interpreted graphically.The skin friction and Nusselt number were also evaluated.In addition,existence of dual solution was deduced for the shrinking sheet and unique solution for the stretching one.Further,Al_(2)O_(3)/H_(2)O nanofluid flow has better thermal conductivity on comparing with Cu/H_(2)O nanofluid.Furthermore,it was found that the first solutions of the stream are stable and physically realizable,whereas those of the second ones are unstable.

关键词： magnetohydrodynamic nanofluid stretching/shrinking sheet axisymmetric flow analytical solution suction/injection