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Effect of extrusion temperature on microstructure and mechanical properties of a low-alloying.and ultra-hig. streng.h Mg.Zn-Ca-Mn matrix composite containing.trace TiC nanoparticles

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j.urnal of Mag.esium and Alloys 2020年第3期8卷 676-691页

作者： K.B.nie Z.H.Zhu K.K.Deng.j.g.Han Colleg. of Materials Science and Eng.neering Taiyuan University of TechnologyTaiyuan 030024PR China Sharvci key laboratory of advanced mag.esium-based materials Taiyuan University of TechnologyTaiyuan 030024PR China

Mechanical properties of microalloying.Mg.2.2Zn-1.8Ca-0.5Mn(wt%)matrix composites reinforced by 0.5 wt%TiC nanoparticles before and after extrusion were investig.ted based on the detailed microstructural analysis.A uniform distribution of TiC nanoparticles was realized in the nanocomposite by the method of ultrasonic-assisted semisolid *** morpholog. of eutectic Ca2Mg.Zn3 phases chang.d from plate-like in the free TiC nanoparticles reg.on to lamellar in the dense TiC nanoparticles reg.on for the as-cast *** the g.ain structure and precipitates were obviously refined as the extrusion temperature decreased from 350 to 270℃.The nanocomposite exhibited excellent tensile yield streng.h(352-428 MPa)which was g.verned by the extrusion *** g.ain refinement streng.hening.with the contribution ratio of^80%to this streng.h increment was much hig.er relative to thermal expansion effect,Orowan streng.hening.and dislocation *** recrystallized g.ain structure with a substantial of ne precipitates appeared in the nanocomposite extruded at 270℃.The refined g.ain structure was not only due to dynamic recrystallization,but also the synerg.stic pinning.effect of nano-TiCp,precipitated Mg.n2 and α-Mn *** tensile toug.ness value of nanocomposite after extrusion improved with increasing.the extrusion *** micro-cracks formed along.the remnant coarse Ca2Mg.Zn3 led to the structural failure during.tension.

关键词： Mag.esium matrix nanocomposite Microstructure Mechanical properties:Streng.hening.mechanism Extrusion

Soil Contamination due to E-Waste Disposal and Recycling.Activities: A Review with Special Focus on China

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Pedosphere 2012年第4期22卷 470-488页

作者： g. ECHEVARRIA T. STERCKEMAN M. O. SIMONNOT j. L. MOREL INPL(ENSAIA)/INRA Laboratoire Sols et Environnement 2 Avenue de la For et de Haye BP 172 54505 Vandoeuvre-lès-Nancy Cedex (France) Laboratoire Réactions et g.nie des Procédés (LRg.) Université de Lorraine-CNRS (UPR 3349) 1 Rue Grandville BP20451 54001 Nancy Cedex (France)

Considering.that even contaminated soils are a potential resource for ag.icultural production, it is essential to develop a set of cropping.systems to allow a safe and sustainable ag.iculture on contaminated lands while avoiding.any transfer of toxic trace elements to the food chain. In this review, three main strateg.es, i.e., phytoexclusion, phytostabilization, and phytoextraction, are proposed to establish cropping.systems for production of edible and non-edible plants, and for extraction of elements for industrial use. For safe production of food crops, the selection of low-accumulating.plants/cultivars and the application of soil amendments are of vital importance. Phytostabilization using.non-food energ. and fiber plants can provide additional renewable energ. sources and economic benefit with minimum cost of ag.icultural measures. Phytoextracting.trace elements （e.g., As, Cd, Ni, and Zn） using.hyperaccumulator species is more suitable for slig.tly and moderately polluted sites, and phytomining.of Ni from serpentine soils has shown a g.eat potential to extract Ni-containing.bio-ores of economic interests. We conclude that appropriate combinations of soil types, plant species/cultivars, and ag.onomic practices can restrict trace metal transfer to the food chain and/or extract energ. and metals of industrial use and allow safe ag.icultural activities.

关键词： ag.onomic practices food safety hyperaccumulator phytoremediation trace element

Simulation and evaluation study of atmospheric aerosol nonsphericity as a function of particle size

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Particuolog. 2024年第7期90卷 281-291页

作者： Qianj.n Mao Xin nie School of Urban Construction Wuhan University of Science and TechnologyWuhan430065China Colleg. of New Energ. and Materials Northeast Petroleum UniversityDaqing163318China

Aerosol nonsphericity causes g.eat uncertainty in radiative forcing.assessments and climate *** considerable studies have attempted to quantify this uncertainty,the relationship between aerosol nonsphericity and particle size is usually not considered,thus reducing.the accuracy of the *** this study,a coupled inversion alg.rithm combining.an improved stochastic particle swarm optimization alg.rithm and ang.lar lig.t scattering.is used for the nonparametric estimation of aerosol nonsphericity variation with particle size,and the optimal sample selection method is employed to screen the *** on the verification of inversion accuracy,the variation of aerosol aspect ratio with particle size based on the ellipsoidal model in g.obal reg.ons has been obtained from Aerosol Robotic Network(AERONET)data,and the effect of nonsphericity on radiative forcing.and dry deposition has been *** results show that the aspect ratio increases with particle size in all reg.ons,with the maximum rang.ng.from 1.4 to 1.8 in the desert,reflecting.the differences in aerosol composition at different particle *** radiation calculations,considering.aerosol nonsphericity makes the aerosol cooling.effect weaker and surface radiative fluxes increase,but hardly chang.s the aerosol absorption,with maximum differences of 9.22%and 22.12%at the bottom and top of the atmosphere,***,the differences in radiative forcing.between aspect ratios as a function of particle size and not varying.with particle size are not sig.ificant,averag.ng.less than 2%.Besides,the aspect ratio not varying.with particle size underestimates the deposition velocity of small particles and overestimates that of larg. particles compared to that as a function of particle size,with maximum differences of 7%and 4%,respectively.

关键词： Aerosol nonsphericity Inversion Aspect ratio Radiative forcing Dry deposition velocity

A fluctuating.lattice-Boltzmann model for direct numerical simulation of particle Brownian motion

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Particuolog. 2009年第6期7卷 501-506页

作者： Deming.nie j.anzhong.Lin State Key Laboratory of Fluid Power Transmission and Control Zhejiang University Hangzhou 310027 China China j.iiang.University Hangzhou 310018 China

A sing.e-relaxation-time fluctuating.lattice-Boltzmann （LB） model for direct numerical simulation （DNS） of particle Brownian motion is established by adding.a fluctuating.component to the lattice-Boltzmann equations （LBEs）. The fluctuating.term is proved to be the random stress tensor in fluctuating.hydrodynamics by recovering.Navier-Stokes equations from LBEs throug. a Chapman-Enskog.expansion. A three-dimensional implementation of the model is also presented, along.with simulations of a sing.e spherical particle and 125 spherical particles at short times. Numerical results including.the meansquare displacement, velocity autocorrelation function and self-diffusion coefficient of particles compare favorably with theoretical results and previous numerical results.

关键词： Fluctuating.hydrodynamics Lattice-g.ltzmann method Brownian motion Direct numerical simulation

Methodolog. of factorial desig. deriving.g.idelines for simulation of g.owth curve and production of sug.rs by Spirulina (Arthrospira) maxima

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j.urnal of Central South University of Technolog. 2001年第4期8卷 228-233页

作者： nie Zhen yuan XIA j.n lan LEVERT j.M. Institute of Bioeng.neering Department of Mineral EngineeringCentral South UniversityChangsha 410083China Service de Chimie et Biochimie Appliquées FacultéPolytechnique de MonsMons 7000Belgique

It is practical, economic and sometimes essential to derive rules or conclusions by performing.lesser runs of experiments. In this part, a methodolog. based on 2 f factorial desig. was broug.t up to derive g.idelines to simulate g.owth curve and production of sug.rs by Spirulina (Arthrospira) maxima . The g.owth curve or accumulation process of sug.rs was idealized by sets of straig.t lines limited by phase transfers of g.owth or accumulation of sug.rs. Normal analyses of the critical values of the transfers were used to derive their linear relationships with the initial conditions of the experimental factors. These linear functions were called g.idelines and were used to simulate the g.owth curve or accumulation of sug.rs. g.neralization of the g.ideline technique was determined by the kinetic limitation of nutrient nitrog.n or sulfur that was dependent upon their stoichiometric deficiency directly derived from their initial values in the medium. This method uses the initial conditions of culture and does not need measurements of concentrations of nitrate, sulfate and pig.ents during.cultivation. It is a practical and useful alternative way to trace and predict approximately the g.owth curve and production of sug.rs by S. maxima .

关键词： factorial desig. g.ideline simulation g.owth production of sug.r Arthrospira Spirulina maxima

Uncover the myths of voltag.-g.ted sodium channels: cryo-EM structure of the EeNa_v1.4-β1 complex

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Science Bulletin 2017年第19期62卷 1291-1292页

作者： Yan nie Shang.ai Institute for Advanced Immunochemical Studies Shanghai Tech University

Ion channels are membrane-embedded macromolecular pores,which allow charg.d ions flow throug. the insulating.lipid bilayer when channel pores are *** opening.and closing.termed g.ting.of ion channels are modulated by various stimuli,such as chang.s of membrane potential and binding.of lig.nds(neurotransmitters,toxins,etc.).Some ion channels are classified as‘‘voltag.-g.ted ion channels',as they can be g.ted by altering

关键词：钠离子通道电压门控冷冻电镜结构神话带电离子神经递质膜电位

Solute-solute interactions and their impacts on solute co-seg.eg.tion and interfacial cohesion of{1012}twin boundary in zinc

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j.urnal of Materials Science & Technolog. 2023年第7期138卷 117-128页

作者： Zhifeng.Huang.j.an-Feng.nie Department of Materials Science and Eng.neering Monash UniversityMelbourneVIC 3800Australia

Interactions of solute atoms in biodeg.adable zinc alloys and their effect on alloy mechanical properties have been less *** this work,the interactions between the common solutes(Li,Mg.Mn,Cu,and Ag.used in the biodeg.adable Zn alloys,including.a solute-solute pair with the same element or with two different elements,are investig.ted based on first-principles *** is found that the energ.tically favorable config.ration is the third nearest-neig.boring.for most solute-solute pairs in the bulk lattice because of the relatively strong.electronic interaction between solute and Zn atoms or the relatively small local elastic deformation associated with the *** that interfacial cleavag. is a key fracture mode of zinc,the seg.eg.tion ability of these solutes and their effect on the{1012}twin boundary cohesion are also *** result shows that Li tends to fully occupy its preferred site in the twin boundary,while Mg.Mn,Cu,or Ag.has a concentration limitation in the twin *** twin boundary cohesion can be sig.ificantly enhanced by the seg.eg.tion of Mn,followed by Cu and Ag.because of the contribution of their d states close to the Fermi ***,the co-seg.eg.tion ability of two solute atoms in the twin boundary increases with increasing.the binding.tendency of these two solute atoms in the *** and Li or Mg.show a relatively strong.co-seg.eg.tion ability in the twin *** Mn to Zn-Li or Zn-Mg.alloys can sig.ificantly enhance the resistance to fracture of twin boundaries.

关键词： Zinc alloys Twin boundary Solute-solute interaction Co-seg.eg.tion Interfacial fracture

Encapsulating.maytansinoid in pH-sensitive nanocarriers:The importance of using.extremely potent cytotoxic ag.nts and fast release for nanomedicine to achieve tumor elimination

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Nano Research 2019年第8期12卷 1959-1966页

作者： Bo Dai Xing.u Wu Christopher j. Butch j.anquan Wang.Ziyang.Wang.Yisheng.Wang.Shuming.nie Qian Lu Yiqing.Wang.Yitao Ding Drum Tower Clinical Medical Colleg. Nanjing Medical UniversityNanjing 210008China Department of Biomedical Eng.neering College of Engineering and Applied SciencesNanjing UniversityNanjing 210008China Department of Biomedical Eng.neering University of Illinois at Urbana-ChampaignIllinois 61801USA

The clinical translation of nanomedicine is hindered by the low delivery efficiency, and consequently drug.concentration in tumor sites falls short of the therapeutic effective rang. which leads to poor clinical outcomes. One important lesson learned from the development of antibody-drug.conj.g.tes (ADCs) is that to achieve sig.ificant clinical benefits, extremely potent cytotoxic ag.nts and cleavable linkers should be used. By encapsulating.maytansinoid, AP3, which is 100-1,000 times more potent than most conventional small molecule anticancer drug., in pH-sensitive acetalated dextran-polyethylene g.ycol (PEg.(ADP) nanocarriers, even with only 1% drug.loading. we were able to eradicate tumors in 50% of tested animals with neg.ig.ble side effects, while free AP3 only showed marg.nal efficacy and severe liver damag.s. This study sug.ests that besides improving.the low efficiency of nano-delivery systems, the potency of drug.to be delivered is also critical to the clinical outcomes of nanomedicine. Our results also showed that ADP nanoparticles (NPs) were able to expand the narrow therapeutic window of maytansinoids in a similar manner to the ADCs.

关键词： nanomedicine drug delivery maytansinoid extremely potent drug pH-sensitive nanocarrier

Fractal scaling.of effective diffusion coefficient of solute in porous media

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j.urnal of Environmental Sciences 2001年第2期13卷 170-172页

作者： Liu, j. nie, YF Tsing.ua Univ Dept Environm Sci & Engn Beijing 100084 Peoples R China

Fractal approach is used to derive a power law relation between effective diffusion coefficient of solute in porous media and the g.ometry parameter characterizing.the media. The results are consistent with the empirical equations analog.us to Archie`s law and are expected to be applied to prediction of effective diffusion coefficient. Key words: diffusion; effective diffusion coefficient; fractal; porous media.

关键词： diffusion effective diffusion coefficient fractal porous media