检索结果-南通市图书馆

粉末冶金法制备Ti6Al4V/20CoCrMo与多孔Ti6Al4V双层生物医用材料的设计与表征

在线全文

学校读者我要写书评

暂无评论

Transactions of Nonferrous Metals Society of China 2021年第1期31卷 178-192页

作者： E.MIHAlCEA H.J.VERGARA-HERNÁNDEZ O.JIMENEZ l.olmos J.CHÁVEZ D.ARTEAGA División de Estudios de Posgrado e Investigación Tecnológico Nacional de México/ITMoreliaAv.Tecnológico#1500Colonia Lomas de SantiaguitoMoreliaC.P.58120México Universidad de Guadalajara DIPJoséGuadalupe Zuno#48Los BelenesZapopanC.P.45100México INICIT Universidad Michoacana de San Nicolás de HidalgoFco.J.Mujica S/NMoreliaC.P.58060México Departamento de Ingeniería Mecánica Eléctrica CUCEIUniversidad de GuadalajaraBlvd.Marcelino García Barragán 1421OlímpicaC.P.44430 GuadalajaraJaliscoMéxico Centro de Geociencias Universidad Nacional Autónoma de MéxicoBlvd.Juriquilla No.3001Querétaro 76230México

制备Ti6Al4V/20CoCrMo与多孔Ti6Al4V生物医用双层复合材料。采用传统粉末冶金技术,以半固态烧结为固结步骤,制备具有致密Ti6Al4V/20CoCrMo表层和多孔Ti6Al4V底层的双层样品,以更好地模拟天然骨。采用膨胀法研究双层试样的致密化行为,通... 详细信息

制备Ti6Al4V/20CoCrMo与多孔Ti6Al4V生物医用双层复合材料。采用传统粉末冶金技术,以半固态烧结为固结步骤,制备具有致密Ti6Al4V/20CoCrMo表层和多孔Ti6Al4V底层的双层样品,以更好地模拟天然骨。采用膨胀法研究双层试样的致密化行为,通过扫描电镜(SEM)和显微计算机断层成像(CMT)观察其显微组织,并分别通过压缩试验和动电位试验评价其力学性能和耐腐蚀性能。结果表明,在界面对致密化无负面影响的情况下,可得到无裂纹的双层样品。多孔层的渗透率值在较低的人体骨骼的渗透率范围内。样品的压缩特性由Ti6Al4V多孔层决定。此外,Ti6Al4V/20CoCrMo的耐腐蚀性能优于Ti6Al4V的耐腐蚀性能,提高双层样品的耐腐蚀性。研究粉末冶金法制备具有致密Ti6Al4V/20CoCrMo表层和多孔Ti6Al4V底层的双层结构材料,有助于生产定制化、具有良好磨损性能和体内寿命的植入物。

关键词：双层结构复合材料孔隙率烧结渗透率压缩行为腐蚀

Cu-WC复合材料涂层的受限烧结和磨损性能（英文）

在线全文

学校读者我要写书评

暂无评论

Transactions of Nonferrous Metals Society of China 2017年第10期27卷 2214-2224页

作者： J.l.CABEZAS-VIllA l.olmos H.J.VERGARA-HERNáNDEZ O.JIMéNEZ P.GARNICA D.BOUVARD M.FlORES División de Estudios de Posgrado e Investigación Tec NM/Instituto Tecnológico de Morelia INICIT Universidad Michoacana de San Nicolás de HidalgoFco.J.Mujica S/N Universidad de Guadalajara Departamento de Ingeniería de Proyectos Univ.Grenoble Alpes CNRS SIMa P

采用固态烧结法制备Cu-WC金属基复合材料涂层。将不同体积分数(5%-30%)的WC增强颗粒与Cu颗粒混合,然后在还原性气氛和垂直膨胀计中于1000°C进行烧结。结果表明,复合材料涂层的烧结动力学受基体材料和WC颗粒的影响,WC颗粒能减缓粉末径... 详细信息

采用固态烧结法制备Cu-WC金属基复合材料涂层。将不同体积分数(5%-30%)的WC增强颗粒与Cu颗粒混合,然后在还原性气氛和垂直膨胀计中于1000°C进行烧结。结果表明,复合材料涂层的烧结动力学受基体材料和WC颗粒的影响,WC颗粒能减缓粉末径向和轴向的致密化。复合材料涂层紧实地粘附于基体上,而WC颗粒随机分布在基体中。与未添加增强剂的样品相比,添加了WC增强剂的样品的显微硬度增加,磨损量降低至原来的1/17。样品在载荷为5 N条件下的主要磨损机理为磨粒磨损,当WC增强剂的体积分数为20%时复合涂层的性能最优。

关键词：受限烧结膨胀法干滑动磨损显微硬度金属基复合材料涂层

机械球磨制备Ni_2FeSb合金的烧结动力学（英文）

在线全文

学校读者我要写书评

暂无评论

Transactions of Nonferrous Metals Society of China 2016年第8期26卷 2126-2135页

作者： F.AlVARADO-HERNáNDEZ O.JIMéNEZ G.GONZAlEZ-CASTANEDA V.BAlTAZAR-HERNáNDEZ J.CABEZAS-VIllA M.AlBITER H.VERGARA-HERNáNDEZ l.olmos Unidad Académica de Ingeniería I Universidad Autónoma de ZacatecasJardín Juárez 147 Centro Histórico Zacatecas Zacatecas C. P. 98000 México Departamento de Ingeniería de Proyectos CUCEI Universidad de GuadalajaraBlvd. Marcelino García Barragán 1421 Olímpica Guadalajara Jalisco C. P. 44430 Mexico INICIT Universidad Michoacana de San Nicolás de HidalgoFco. J. Mujica S/N C.U. Morelia Michoacán C. P. 58060 México División de Estudios de Posgrado e Investigación TecNM/Instituto Tecnológico de MoreliaAv. Tecnológico # 1500 Colonia Lomas de Santiaguito Morelia Michoacán C. P. 58120 México

采用粉末冶金工艺制备Ni2FeSb三元形状记忆合金。利用膨胀实验研究合金的烧结动力学；采用XRD和SEM分别考察粉末样品和烧结样品的显微组织和形貌；测定烧结样品表面的显微硬度。结果表明：研磨时间对粉末样品的形状、晶粒尺寸和晶体结... 详细信息

采用粉末冶金工艺制备Ni2FeSb三元形状记忆合金。利用膨胀实验研究合金的烧结动力学；采用XRD和SEM分别考察粉末样品和烧结样品的显微组织和形貌；测定烧结样品表面的显微硬度。结果表明：研磨时间对粉末样品的形状、晶粒尺寸和晶体结构的均匀性具有显著影响。经较长时间研磨的样品具有较高的相对密度和较均匀的元素分布，且为l21和马氏体相，这些性能使合金具有形状记忆功能。在温度为750~1273K条件下，合金的激活能为109~283kJ/mol，这表明烧结过程主要由体积扩散控制。增加研磨时间和加热速率，合金的显微硬度得到提高。

关键词： Ni基形状记忆合金机械球磨固态烧结显微硬度

On the functions of astrocyte-mediated neuronal slow inward currents

在线全文

学校读者我要写书评

暂无评论

Neural Regeneration Research 2024年第12期19卷 2602-2612页

作者： Balázs Pál Department of Physiology Faculty of MedicineUniversity of DebrecenDebrecenHungary

Slow inward currents are known as neuronal excitatory currents mediated by glutamate release and activation of neuronal extra synaptic N-met hyl-D-aspartate receptors with the contribution of astrocytes.These events are significantly slower than the excitatory postsynaptic currents.Parameters of slow inward currents are determined by seve ral factors including the mechanisms of astrocytic activation and glutamate release,as well as the diffusion pathways from the release site towards the extra synaptic recepto rs.Astrocytes are stimulated by neuronal network activity,which in turn excite neurons,forming an astrocyte-neuron feedback loop.Mostly as a consequence of brain edema,astrocytic swelling can also induce slow inward currents under pathological conditions.There is a growing body of evidence on the roles of slow inward currents on a single neuron or local network level.These events often occur in synchro ny on neurons located in the same astrocytic domain.Besides synchronization of neuronal excitability,slow inward currents also set synaptic strength via eliciting timing-dependent synaptic plasticity.In addition,slow inward currents are also subject to non-synaptic plasticity triggered by long-la sting stimulation of the excitatory inputs.Of note,there might be important regionspecific differences in the roles and actions triggering slow inward currents.In greater networks,the pathophysiological roles of slow inward currents can be better understood than physiological ones.Slow inward currents are identified in the pathophysiological background of autism,as slow inward currents drive early hypersynchrony of the neural networks.Slow inward currents are significant contributors to paroxysmal depolarizational shifts/interictal spikes.These events are related to epilepsy,but also found in Alzheimer's disease,Parkinson's disease,and stroke,leading to the decline of cognitive functions.Events with features overlapping with slow inward currents(excitatory,N-methyl-Daspartate-receptor mediated currents with astrocyti

关键词： astrocyte cortical spreading depolarization gliotransmission glutamate neural synchronization NMDA receptor paroxysmal depolarizational shift slow inward current

Complex-frequency waves:beat loss and win sensitivity

在线全文

学校读者我要写书评

暂无评论

light(Science & Applications) 2024年第2期13卷 181-183页

作者： Qingqing Cheng Tao l School of Optical-Electrical and Computer Engineering University of Shanghai for Science and TechnologyShanghai200093China Department of Respiratory Diseases and Critical Medicine Quzhou Hospital Affiliated to Wenzhou Medical UniversityQuzhou324000China National laboratory of Solid State Microstructures College of Engineering and Applied SciencesNanjing UniversityNanjing210093China

Recent experiments have demonstrated that synthesized complex-frequency waves can impart a virtual gain to molecule sensing systems,which can effectively restore information lost due to intrinsic molecular damping.The enhancement notably amplifies the signal of trace molecular vibrational fingerprints,thereby substantially improving the upper limit of sensitivity.

关键词： thereby Complex limit

Effect of radiative loss mechanisms on FIR thermometric parameters of Nd3+-doped lithium tellurite glasses

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Rare Earths 2024年第7期42卷 1250-1257页

作者： C.Y.Morassuti A.P.l Silva l.A.O.Nunes S.M.lima l.H.C.Andrade Optical and Photothermal Spectroscopy Group (GEOF) Center for Studies in Natural Resources (CERNA)State University of Mato Grosso do Sul(UEMS) Renato Archer Information Technology Center Institute of Physics of Sao Carlos University of S?o Paulo

Nd3+-doped tellurite glasses are promising materials for thermometers based on the fluorescence intensity ratio（FIR） technique.Nevertheless,at high Nd3+concentrations,energy transfer（ET） processes such as optical reabsorption and cross-relaxation can affect the Nd3+emission,which has been little explored in the literature.Therefore,the present work investigated the use of Nd3+-doped tellurite glass(samples doped with Nd3+at 0.2 mol%,0.5 mol%,2.0 mol%,and 4.0 mol%) in fluorescence thermometers,in the temperature range from 299 to 371 K.The results indicate a strong dependence of the FIR parameters on the Nd3+concentration,due to changes in the emission band profiles caused by optical reabsorption of the Nd3+emissions and cross-relaxation processes.A decrease of the relative sensitivity of the ratio4F5/2→4I9/2/4F3/2→4I9/2is observed for samples doped with higher amounts of Nd3+.The maximum relative sensitivity at 299 K is 3.00%/K,which is the highest value among the reported Nd3+ions.

关键词： Fluorescence intensity ratio Judd-Ofelt Nd3+-doped tellurite glass Optical thermometry Rare earths

Cognition and movement in neurodegenerative disorders:a dynamic duo

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Neural Regeneration Research 2024年第10期19卷 2101-2102页

作者： Marit F.l.Ruitenberg Department of Health Medical and NeuropsychologyLeiden UniversityLeidenthe Netherlands leiden Institute for Brain and Cognition Leidenthe Netherlands

People with neurodegenerative disorders often experience problems across a variety of functional domains,including cognition,movement,and psychosocial functioning.The classification of these disorders is based on the phenotypical manifestations that represent the most prominent clinical features.For example,Parkinson's disease and Huntington's disease are typically regarded as movement disorders,whereas Alzheimer's disease(AD) and other dementias are regarded as cognitive disorders.

关键词： disorders Huntington degenerative

Time-inconsistent stochastic linear-quadratic control problem with indefinite control weight costs

在线全文

学校读者我要写书评

暂无评论

Science China Mathematics 2024年第1期67卷 211-236页

作者： Qi lü Bowen Ma School of Mathematics Sichuan UniversityChengdu 610064China

A time-inconsistent linear-quadratic optimal control problem for stochastic differential equations is studied.We introduce conditions where the control cost weighting matrix is possibly singular.Under such conditions,we obtain a family of closed-loop equilibrium strategies via multi-person differential games.This result extends Yong’s work(2017) in the case of stochastic differential equations,where a unique closed-loop equilibrium strategy can be derived under standard conditions(namely,the control cost weighting matrix is uniformly positive definite,and the other weighting coefficients are positive semidefinite).

关键词： linear-quadratic optimal control problem time-inconsistent cost functional generalized Riccati equation indefinite control weight cost closed-loop equilibrium strategy

Rogue wave solutions and rogue-breather solutions to the focusing nonlinear Schr?dinger equation

在线全文

学校读者我要写书评

暂无评论

Communications in Theoretical Physics 2024年第3期76卷 33-41页

作者： Si-Jia Chen Xing lü College of Science Tianjin University of TechnologyTianjin 300384People's Republic of China Department of Mathematics Beijing Jiaotong UniversityBeijing 100044People's Republic of China Beijing laboratory of National Economic Security Early-warning Engineering Beijing Jiaotong UniversityBeijing 100044People's Republic of China

Based on the long wave limit method,the general form of the second-order and third-order rogue wave solutions to the focusing nonlinear Schr?dinger equation are given by introducing some arbitrary parameters.The interaction solutions between the first-order rogue wave and one-breather wave are constructed by taking a long wave limit on the two-breather solutions.By applying the same method to the three-breather solutions,two types of interaction solutions are obtained,namely the first-order rogue wave and two breather waves,the second-order rogue wave and one-breather wave,respectively.The influence of the parameters related to the phase on the interaction phenomena is graphically demonstrated.Collisions occur among the rogue waves and breather waves.After the collisions,the shape of them remains unchanged.The abundant interaction phenomena in this paper will contribute to a better understanding of the propagation and control of nonlinear waves.

关键词： nonlinear Schrodinger equation rogue wave solutions interaction solutions