检索结果-南通市图书馆

结构性多孔钽生物材料用于成人重建术的临床论证

在线全文

学校读者我要写书评

暂无评论

骨科动态 2005年第3期1卷 147-152页

作者： DENNIS BoBYN R.A.PoGGIE j.j.KRYGIER D.G.LEWALLEN A.D.HANSSEN R.j.LEWIS A.S.UNGER t.j.o＇keefe M.j.CHRIStIE S.NASSER j.E.WooD S.D.StULBERG M.tANZER 王毅（译）不详上海第二医科大学附属瑞金医院骨科 200025

在过去的三十年中，大多数钽珠烧结以及钽纤维丝弥散结合制造的多孔涂层，已用于骨科植入物的生物连接。近十年来，诞生了一种由商业纯钽制成的，具有独特物理和力学特性的新型多孔生物材料。与传统多孔涂层相比，该材料拥有更高的空隙... 详细信息

在过去的三十年中，大多数钽珠烧结以及钽纤维丝弥散结合制造的多孔涂层，已用于骨科植入物的生物连接。近十年来，诞生了一种由商业纯钽制成的，具有独特物理和力学特性的新型多孔生物材料。与传统多孔涂层相比，该材料拥有更高的空隙容积、更自由连通的孔、与骨更高的摩擦系数，以及较低的成块硬化性（图1）。此外，该材料为结构性的，有足够的强度可以直接制造植入体，而无需实心的金属基质作支撑。

关键词：多孔生物材料结构重建术骨科植入物钽临床成人生物连接力学特性

the CCD instrument background of the SMILE SXI

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Earth and Planetary Physics 2024年第1期8卷 15-24页

作者： M.W.j.Hubbard o.Hetherington D.j.Hall t.W.Buggey S.Parsons t.Arnold A.Holland C.Pagani S.Sembay Centre for Electronic Imaging The Open UniversityMilton KeynesMK76AAUK X-ray and observational Astronomy Group Department of Physics&AstronomyUniversity of LeicesterLE17RHUK

the ESA and CAS SMILE mission orbit is highly elliptical and will pass through multiple radiation *** Soft X-ray Imager(SXI)instrument aboard has a radiation shutter door designed to close when the surrounding radiation flux is *** shutter door will close when passing below an altitude threshold to protect against trapped particles in the Earth’s Van Allen ***,two radiation environments can be approximated based on the shutter door position:open and *** instrument background for the CCDs(Charge-Coupled Devices)that form the focal plane array of the SXI were evaluated for the two *** to the correlation of the space environment with the solar cycle,the solar minima and maxima,the background was also evaluated at these two *** results demonstrated that the highest instrument background will occur during solar minima due to the main contributing source being Galactic Cosmic Rays(GCRs).It was also found that the open background was highest for solar minima and that the closed background was highest during solar *** is due to the radiation shutter door acting as a scattering centre and the changes in the energy flux distribution of the GCRs between the two solar extremes.

关键词： instrument background X-ray astronomy space radiation

In situ characterization of particle formation in spray flame synthesis using wide-angle light scattering

在线全文

学校读者我要写书评

暂无评论

Particuology 2024年第3期86卷 304-312页

作者： Simon Aβmann Franz j.t.Huber Stefan Will Lehrstuhl für technische thermodynamik(Ltt) Friedrich-Alexander-Universitat Erlangen-Nürnberg(FAU)Erlangen91058Germany Erlangen Graduate Schoolin Advanced optical technologies(SAot) Friedrich-Alexander-Universitat Erlangen-Nurnberg(FAU)Erlangen91052Germany Competence Unit Engineering of Advanced Materials(EAM) Friedrich-Alexander-Universitat Erlangen-Nürnberg(FAU)Erlangen91052Germany

Wide-angle light scattering(WALS)was used for in situ measurements of droplet and nanoparticle size distributions during the synthesis of titania and iron oxide particles from liquid precursor solutions in the standardized SpraySyn burner for spray flame *** was synthesized from titanium tetraisopropoxide(ttIP)and iron oxide from iron(II)nitrate nonahydrate(INN)using ethanol(EtoH)as *** images were taken at heights up to 120 mm above the burner surface and classified into droplet and particle *** size distributions were derived from a sequential analysis of scattering data containing the oscillating Mie pattern,the lognormal size distribution parameters for spherical and fractal particle fractions from a multivariate approach on averaged particle scattering *** results show that the precursor addition leads to altered evaporation behavior and even droplet disruption probably induced by puffing or micro-explosions compared to pure *** the case of ttIP(a hygroscopic alkoxide),the synthesis of a large fraction of spheres was observed,while the nitrate INN leads to the formation of mostly fractal aggregates.

关键词： Spray flame synthesis Metal oxide particles Elastic light scattering Droplet size distribution Nanoparticle morphology Particle size distribution

Impact of device resistances in the performance of graphene‑based terahertz photodetectors

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Frontiers of optoelectronics 2024年第2期17卷 87-97页

作者： o.Castelló Sofía M.López Baptista K.Watanabe t.taniguchi E.Diez j.E.Velázquez-Pérez Y.M.Meziani j.M.Caridad j.A.Delgado-Notario Department of Applied Physics University of Salamanca37008 SalamancaSpain Unidad de Excelencia en Luz y Materia Estructurada(LUMES) University of Salamanca37008 SalamancaSpain Research Center for Electronic and optical Materials National Institute for Materials Science1-1 NamikiTsukuba 305-0044Japan Research Center for Materials Nanoarchitectonics National Institute for Materials Science1-1 NamikiTsukuba 305-0044Japan Nanotechnology Group USAL-NanolabUniversity of Salamanca37008 SalamancaSpain

In recent years,graphene field-effect-transistors(GFEts)have demonstrated an outstanding potential for terahertz(tHz)photodetection due to their fast response and *** features are essential to enable emerging tHz applications,including 6G wireless communications,quantum information,bioimaging and ***,the overall performance of these photodetectors may be utterly compromised by the impact of internal resistances presented in the device,so-called access or parasitic *** this work,we provide a detailed study of the influence of internal device resistances in the photoresponse of high-mobility dual-gate GFEt *** dual-gate architectures allow us to fine tune(decrease)the internal resistance of the device by an order of magnitude and consequently demonstrate an improved responsivity and noise-equivalent-power values of the photodetector,*** results can be well understood by a series resistance model,as shown by the excellent agreement found between the experimental data and theoretical *** findings are therefore relevant to understand and improve the overall performance of existing high-mobility graphene photodetectors.

关键词： Graphene tHz Photodetector Field-effect transistor Plasmonic

Reply to the note by Li Piani et al.

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Defence technology（防务技术） 2024年第1期31卷 603-606页

作者： t.Li Piani j.Weerheijm L.j.Sluys tU Delft Stevinweg 12628 CNDelftthe Netherlands tNo PO Box 452280 AARijswijkthe Netherlands NLDA Faculty of Military Sciences1781 CADen Helderthe Netherlands

In 2017,a ballistic phenomenological model was proposed by the authors of Ref.[1] to numerically simulate the experimental depths of small caliber projectiles impacting walls made of *** opportunity for a new model in the field revealed from the observation that two older models recently used by the authors of Ref.[2] shared a linear relationship between the penetration depth P and the impacting velocity v_(o).

关键词： Penetration Adobe Modeling

Mathematical modelling of ball and plate system with experimental and correlation function-based model validation

在线全文

学校读者我要写书评

暂无评论

Control theory and technology 2024年第2期22卷 326-341页

作者： t.R.Dil Kumar S.j.Mija Department of Electrical Engineering National Institute of Technology CalicutKozhikode673601KeralaIndia

the ball and plate system is an inherently nonlinear under actuated benchmark system used for validating the performance of various control schemes. A mathematical model depicting the dynamics close to that of the system is very much required for such a test bed. In this correspondence, the complete nonlinear model, a simplified nonlinear model, and a linearized model of the ball and plate system are developed. the system comprises a ball and plate mechanism and a rotary servo unit. the ball and plate mechanism is modelled using the Euler–Lagrange method, whereas the rotary servo subsystem is modelled from the first principles. the nonlinear model of the combined system is developed by including the dynamics of the servo motor with gear and rolling resistance between the ball and the plate. the simplified nonlinear model of the system is obtained with suitable assumptions. the model is linearized around the operating point using the jacobian. the validity of the developed models is investigated through correlation function analysis. the open-loop response of the three models, viz., nonlinear, simplified nonlinear, and linearized models, is analyzed in the MAtLAB/Simulink platform. Since the open-loop system is unstable, the experimental validation of the model is performed with a double-loop PSo (particle swarm optimization) PID control scheme.

关键词： Ball and plate system Correlation function Model validation Particle swarm optimization(PSo) PSo PID controller

Superplasticity of fine-grained Mg-10Li alloy prepared by severe plastic deformation and understanding its deformation mechanisms

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 Magnesium and Alloys 2024年第1期12卷 316-331页

作者： H.t.j.ong S.W.Lee W.j.Kim Department of Materials Science and Engineering Hongik UniversityMapo-guSangsu-dong 72-1Seoul 121-791Republic of Korea

the superplastic behavior and associated deformation mechanisms of a fine-grained Mg-10.1 Li-0.8Al-0.6Zn alloy(LAZ1011)with a grain size of 3.2μm,primarily composed of the BCCβphase and a small amount of the HCPαphase,were examined in a temperature range of 473 K to 623 *** microstructural refinement of this alloy was achieved by employing high-ratio differential speed *** best superplasticity was achieved at 523 K and at strain rates of 10^(-4)-5×10^(-4)s^(-1),where tensile elongations of 550±600%were *** the heating and holding stage of the tensile samples prior to tensile loading,a significant increase in grain size was observed at temperatures above 573 ***,it was important to consider this effect when analyzing and understanding the superplastic deformation behavior and *** the investigated strain rate range,the superplastic flow at low strain rates was governed by lattice diffusion-controlled grain boundary sliding,while at high strain rates,lattice diffusion-controlled dislocation climb creep was the rate-controlling deformation *** was concluded that solute drag creep is unlikely to *** the late stages of deformation at 523 K,it was observed that grain boundary sliding led to the agglomeration of theαphase,resulting in significant strain *** mechanism maps were constructed forβ-Mg-Li alloys in the form of 2D and 3D formats as a function of strain rate,stress,temperature,and grain size,using the constitutive equations for various deformation mechanisms derived based on the data of the current tests.

关键词： Magnesium-lithium alloy Superplasticity Severe plastic deformation Grain size Grain growth

Academic productivity correlates with industry earnings in foot and ankle fellowship programs in the United States:A retrospective analysis

在线全文

学校读者我要写书评

暂无评论

World journal of orthopedics 2024年第2期15卷 129-138页

作者： Albert t Anastasio Anthony N Baumann Kempland C Walley Kyle j Hitchman Conor o’Neill jonathan Kaplan Samuel B Adams Department of orthopedic Surgery Duke University HospitalDurhamNC 27710United States College of Medicine Northeast Ohio Medical UniversityRootstownOH 44272United States Department of orthopedic Surgery University of MichiganAnn ArborMI 48109United States School of osteopathic Medicine Campbell UniversityLillingtonNC 27546United States

BACKGRoUND the study investigates the connection between academic productivity and industry earnings in foot and ankle orthopedic surgery *** metrics like the H-index and open Payments Database(oPD)data,it addresses a gap in understanding the relationship between scholarly achievements and financial outcomes,providing a basis for further exploration in this specialized medical *** to elucidate the trends between academic productivity and industry earnings across foot and ankle orthopedic surgery fellowship programs in the United *** this study is a retrospective analysis of the relationship between academic productivity and industry earnings of foot and ankle orthopedic surgery fellowships at an individual faculty and fellowship *** productivity was defined via H-index and recorded from the Scopus *** earnings were recorded from the *** Forty-eight foot and ankle orthopedic surgery fellowships(100%of fellowships)in the United States with a combined total of 165 physicians(95.9%of physicians)were *** individual physician(n=165)total life-time earnings reported on the oPD website was United States Dollar(USD)451430.30±1851084.89(range:USD 25.16-21269249.85;median:USD 27839.80).Mean physician(n=165)H-index as reported on Scopus is 14.24±12.39(range:0-63;median:11).there was a significant but weak correlation between individual physician H-index and individual physician total life-time earnings(Po=0.334)and a significant and moderate positive correlation between combined fellowship H-index and total life-time earnings per fellowship(P=0.004,Spearman’s rho=0.409).CoNCLUSIoN there is a significant and positive correlation between academic productivity and industry earnings at foot and ankle orthopedic surgery fellowships in the United *** observation is true on an individual physician level as well as on a fellowship level.

关键词： Sunshine act Foot and ankle orthopedic surgery orthopedic fellowship Industry earnings

thermoluminescence characterization of natural and synthetic irradiated Ce-monazites

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