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免耕制度下耕作土壤结构演化的数字图像分析

土壤学报 2002年第2期39卷 214-220页

作者：李德成 B.Velde j.f.delerue 张桃林中国科学院南京土壤研究所南京210008 Laboratoire de Géologie

利用数字图像方法 ,研究了室内模拟和自然田间免耕下的土壤结构演化状况。图像定性表明随免耕时间的推移土壤中团聚体由小变大 ,土体逐渐趋于紧实。图像定量分析结果表明随着免耕时间的推移 ,小团聚体和小孔隙减少而大团聚体和大孔隙增... 详细信息

利用数字图像方法 ,研究了室内模拟和自然田间免耕下的土壤结构演化状况。图像定性表明随免耕时间的推移土壤中团聚体由小变大 ,土体逐渐趋于紧实。图像定量分析结果表明随着免耕时间的推移 ,小团聚体和小孔隙减少而大团聚体和大孔隙增加。田间土样的结果表明了自然的阶段性降雨对土壤结构可能具有一定的调节作用 ,但从图像与团聚体粒径分布和孔隙孔径分布的变化来看。

关键词：免耕土壤结构团聚体粒径分布孔隙孔径分布数字图像结构演化耕作制度

利用土壤切片及数字图像研究低丘缓坡不同部位土壤的孔隙结构特征

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土壤通报 2002年第1期33卷 6-8页

作者：李德成 B.Velde j.f.delerue 张桃林中国科学院南京土壤研究所江苏南京210008 LaboratoireofGeologie

利用土壤切片及数字图像技术 ,初步研究了葡萄种植园低丘缓坡不同部位 (坡顶、坡中和坡底 )土壤的孔隙结构特征。结果表明 :孔隙面积随着深度的增加而减小 ,孔隙构成以直径小于 1mm的小孔隙为主 ,且随着深度增加小孔隙比重增加 ,不同部... 详细信息

利用土壤切片及数字图像技术 ,初步研究了葡萄种植园低丘缓坡不同部位 (坡顶、坡中和坡底 )土壤的孔隙结构特征。结果表明 :孔隙面积随着深度的增加而减小 ,孔隙构成以直径小于 1mm的小孔隙为主 ,且随着深度增加小孔隙比重增加 ,不同部位孔隙结构具有一定的差异。

关键词：孔隙结构缓坡部位土壤切片数字图像低丘缓坡葡萄园土壤

Thermo-kinetic characteristics on stabilizing hetero-phase interface of metal matrix composites by crystal plasticity finite element method

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journal of Materials Science & Technology 2024年第2期169卷 53-67页

作者： Y.B.Zhang S.j.Song f.Liu State Key Laboratory of Solidification Processing Northwestern Polytechnical UniversityXi’an 710072China Analytical&Testing Center Northwestern Polytechnical UniversityXi’an 710072China

Using dislocation-based constitutive modeling in three-dimension crystal plasticity finite element(3D CPfE)simulations,co-deformation and instability of hetero-phase interface in different material systems were herein studied for polycrystalline metal matrix composites(MMCs).Local stress and strain fields in two types of 3layer MMCs such as fcc/fcc Cu-Ag and fcc/bcc Cu-Nb have been predicted under simple compressive ***,more severe strain-induced interface instability can be observed in the fcc/bcc systems than in the fcc/fcc systems upon refining to metallic nanolayered composites(MNCs).By detailed analysis of stress and strain localization,it has been demonstrated that the interface instability is always accompanied by high-stress concentration,i.e.,thermodynamic characteristics,or high strain prevention i.e.,kinetic characteristics,at the hetero-phase *** then follows that the thermodynamic driving forceG and the kinetic energy barrier Q during dislocation and shear banding can be adopted to classify the deformation modes,following the so-called thermo-kinetic *** by inserting a high density of high-energy interfaces into the Cu-Nb composites,such thermo-kinetic integration at the hetero-phase interface allows a successful establishment of MMCs with the high△G-high Q deformation mode,which ensures high hardening and uniform strain distri-bution,thus efficiently suppressing the shear band,stabilizing the hetero-phase interface,and obtaining an exceptional combination in strength and *** hetero-phase interface chosen by a couple of thermodynamics and kinetics can be defined as breaking the thermo-kinetic correlation and has been proposed for artificially designing MNCs.

关键词： Thermodynamics and kinetics Physics-based constitutive modeling Hetero-phase interface Crystal plasticity finite element

Inflow and outflow permeability tests in a very soft clay under low stresses

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journal of Rock Mechanics and Geotechnical Engineering 2024年第8期16卷 3270-3283页

作者： j.W.S.Vargas f.A.B.Danziger f.R.Lopes T.Lunne federal University of Rio de janeiro Rio de JaneiroBrazil Norwegian Geotechnical Institute OsloNorway

In situ inflow and outflow permeability tests with the BAT probe at SarapuíII soft clay test site are presented.A description of the BAT permeability test is provided,discussing its advantages and shortcomings,especially in the case of very soft clays under low *** pressures were monitored during probe installation and were found to be slightly lower than piezocone u2 pore pressures,consistent with the position of the *** role of filter tip saturation was investigated after the usual saturation procedure provided an unsatisfactory pore pressure response during probe *** show that the vacuum saturation procedure provides adequate response during installation and increases the reliability of the coefficient of permeability determination in early *** inflow and outflow tests yielded similar results,indicating that careful execution of the test can lead to good test repeatability regardless of the loading *** sequences of alternated inflow and outflow tests have yielded similar results,indicating that soil reconsolidation and filter clogging were negligible in the tests *** are presented concerning the relationship between index parameters and the in situ coefficient of permeability for SarapuíII clay,which plot outside the range of existing databases.

关键词： Permeability test Soft clay BAT probe Inflow and outflow tests

Thermoluminescence characterization of natural and synthetic irradiated Ce-monazites

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journal of Rare Earths 2024年第4期42卷 643-650页

作者： V.Correcher C.Boronat j.Garcia-Guinea j.f.Benavente T.Rivera-Montalvo CIEMAT Av.Complutense 4028040MadridSpain MNCN-CSIC J.Gutierrez Abascal 228006MadridSpain Instituto Politécnico Nacional CICATA-IPNAv.Legaria 694Mexico City11500Mexico

The thermoluminescence(TL)emission of synthetic and natural Ce-monazites was characterized here to determine the potential application in the identification of microscopic defects from a qualitative point of view trying to link each TL peak to a chemical-physical *** kinetic parameters that lead the luminescence processes were calculated by means of variable heating rate and computing glow curve deconvolution methods and allow identifying three groups of components at~90,130 and 290℃(for the mineral sample)and~90,170,220,270 and 320℃(for the synthetic CePO_(4):Nd_(0.20),La_(0.25)).The main differences appreciated in these complex TL curves are mainly due to(i)the content of impurities(natural sample contains lanthanides as well as U 0.60%and Th 5.22%)and(ii)the degree of crystallinity of the samples which is directly related to the type of impurities(synthetic monazite relies only on Nd and La).The behavior of the dose response in the range of 1-8 Gy is similar for both samples;the TL intensity increases linearly as the dose increases without changes in the position of the maxima,denoting first-order kinetic luminescence *** peak could be mostly associated with structural defects(i.e.,phase transitions),chemical reactions(i.e.,Ce3+?Ce4+redox reaction,dehydration or dehydroxylation processes)or intrinsic defects(i.e.,frenkel defects,ODCs or NBOHCs).

关键词： Thermoluminescence Kineticparameters Phosphate Ce-monazite Defects Rare earths

On the analytical solution of transient friction in channel flows

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Applied Mathematics and Mechanics(English Edition) 2024年第8期45卷 1447-1466页

作者： f.j.GARCíA-GARCíA P.fARINAS-ALVARINO Department of Naval&Industrial Engineering Polytechnic School of EngineeringUniversity of A CorunaCampus Industrial de FerrolFerrol 15403A CorunaSpain Integraciones Técnicas de Seguridad S.A.Pol.Ind.Espiritu SantoC/Nobel15Cambre 15650A CorunaSpain

The transient friction in channel mean flows is the sum of two contributions,i.e.,the underlying laminar flow(ULf)and the purely turbulent component(PTC),and the contributions are analyzed separately by theoretical *** is found that,the transient friction may be higher or remarkably lower than that in equal-Reynolds number steady-state *** universal time constant for plane-parallel laminar flows is reported,and the role of the time constant in a turbulent mean flow is *** is shown that the time constant is related to the turbulence's frozen ***,a study of the logarithmic layer during the transient flow is accomplished,which shows that the logarithmic layer is destroyed.

关键词： transient friction transient flow unsteady channel flow

Resistive field generation in intense proton beam interaction with solid targets

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Matter and Radiation at Extremes 2024年第1期9卷 35-43页

作者： W.Q.Wang j.j.Honrubia Y.Yin X.H.Yang f.Q.Shao Department of Physics National University of Defense TechnologyHunanChina ETSI Aeronáutica y del Espacio Universidad Politécnica de MadridMadridSpain Department of Nuclear Science and Technology National University of Defense TechnologyHunanChina

The Brown-Preston-Singleton(BPS)stopping power model is added to our previously developed hybrid code to model ion beam-plasma *** simulations show that both resistive field and ion scattering effects are important for proton beam transport in a solid target,in which they compete with each *** the target is not completely ionized,the self-generated resistive field effect dominates over the ion scattering ***,when the target is completely ionized,this situation is ***,it is found that Ohmic heating is important for higher current densities and materials with high *** energy fraction deposited as Ohmic heating can be as high as 20%-30%.Typical ion divergences with half-angles of about 5°-10°will modify the proton energy deposition substantially and should be taken into account.

关键词： interaction beam intense

Mathematical modeling and simulations of stress mitigation by coating polycrystalline particles in lithium-ion batteries

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Applied Mathematics and Mechanics(English Edition) 2024年第6期45卷 947-962页

作者： N.IQBAL j.CHOI S.f.SHAH C.LEE S.LEE Department of Mechanical Roboticsand Energy EngineeringDongguk University-SeoulSeoul 04620Republic of Korea

A chemo-mechanical model is developed to investigate the effects on the stress development of the coating of polycrystalline Ni-rich LiNixMnyCo_(z)O_(2)(x≥0.8)(NMC)particles with poly(3,4-ethylenedioxythiophene)(PEDOT).The simulation results show that the coating of primary NMC particles significantly reduces the stress generation by efficiently accommodating the volume change associated with the lithium diffusion,and the coating layer plays roles both as a cushion against the volume change and a channel for the lithium transport,promoting the lithium distribution across the secondary particles more ***,the lower stiffness,higher ionic conductivity,and larger thickness of the coating layer improve the stress *** paper provides a mathematical framework for calculating the chemo-mechanical responses of anisotropic electrode materials and fundamental insights into how the coating of NMC active particles mitigates stress levels.

关键词： lithium-ion battery(LIB) polycrystalline particle coating finite element simulation Ni-rich LiNixMnyCo_(z)O_(2)(x>0.8)(NMC)

Threshold-Based Software-Defined Networking(SDN)Solution for Healthcare Systems against Intrusion Attacks

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Computer Modeling in Engineering & Sciences 2024年第2期138卷 1469-1483页

作者： Laila M.Halman Mohammed j.f.Alenazi Department of Computer Engineering College of Computer ScienceKing Saud UniversityRiyadh11451Saudi Arabia

The healthcare sector holds valuable and sensitive *** amount of this data and the need to handle,exchange,and protect it,has been increasing at a fast *** to their nature,software-defined networks(SDNs)are widely used in healthcare systems,as they ensure effective resource utilization,safety,great network management,and *** this sector,due to the value of thedata,SDNs faceamajor challengeposed byawide range of attacks,such as distributed denial of service(DDoS)and probe *** attacks reduce network performance,causing the degradation of different key performance indicators(KPIs)or,in the worst cases,a network failure which can threaten human *** can be significant,especially with the current expansion of portable healthcare that supports mobile and wireless devices for what is called mobile health,or *** this study,we examine the effectiveness of using SDNs for defense against DDoS,as well as their effects on different network KPIs under various *** propose a threshold-based DDoS classifier(TBDC)technique to classify DDoS attacks in healthcare SDNs,aiming to block traffic considered a hazard in the form of a DDoS *** then evaluate the accuracy and performance of the proposed TBDC *** technique shows outstanding performance,increasing the mean throughput by 190.3%,reducing the mean delay by 95%,and reducing packet loss by 99.7%relative to normal,with DDoS attack traffic.

关键词： Network resilience network management attack prediction software defined networking(SDN) distributed denial of service(DDoS) healthcare