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Correlations of Structural, Dielectric, Magnetic and Magnetoelectric Properties of Ca1-xSrx(Fe0.5Ta0.5)O3Multiferroic Ceramics

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Materials Sciences and Applications 2017年第1期8卷 64-84页

作者： M.k.h.Bhuiyan M.A.Gafur M.N.I.k.an A.A.Momin A.k.M.Ak.her hossain Department of Physics Bangladesh University of Engineering&TechnologyDhakaBangladesh Pilot Plant&Process Development Centre DhakaBangladesh Materials Science Division Atomic Energy CentreDhakaBangladesh

Conventional solid state reaction technique was used to synthesize Ca1-xSrx(Fe0.5Ta0.5)O3 multiferroic ceramics (where x = 0.0, 0.1, 0.2, 0.3, 0.4 and 0.5). Powder of ingredients was mixed thoroughly in stoichiometric amount and calcined at 1150°C for 5 h. Disk.and toroid shaped samples prepared from each composition were sintered at 1450°C for 5 h. The XRD analysis confirms that all compositions are single phase cubic perovsk.te structure. The theoretical and bulk.density increases with increase of Sr content, which may be attributed to the fact that the atomic weight and density of Sr are larger than those of Ca. The average grain size increased with increasing Sr content up to x = 0.2, and then decreased with further increase of Sr content. Frequency dependent dielectric constant shows usual dielectric dispersion at lower frequencies due to Maxwell-Wagner type interfacial polarization. The higher values of real and imaginary part of impedance at lower frequencies are also due to the fact that all k.nds of polarization mechanism are present and increase with Sr content indicating the enhancement property of the composition. The continuous dispersion on increasing frequency contributes to the conduction phenomena. Two semicircles correspond to the grain boundary and grain resistance separately. The complex modulus analysis reveals the polaron hopping and negligibly small contribution of electrode effect. The continuous dispersion on increasing frequency may be contributed to the conduction phenomena. The ac conductivity, σac, was derived from the dielectric measurement and it increases with increase of frequency for all the compositions and can also be explained on the basis of polaron hopping mechanism. At higher frequencies conductive grains are more active, and thereby increases of hopping of charge carrier contribute to rise in conductivity. The real part of initial permeability increased with increasing Sr content up to x = 0.2, and then decreased further incr

关键词： Perovsk.te Impedance Spectroscopy Initial Permeability Saturation Magnetization Magnetoelectric Voltage Coefficient

Formation mechanisms of sub-micron pharmaceutical composite particles derived from far-and near-field Raman microscopy

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Journal of Pharmaceutical Analysis 2021年第4期11卷 480-489页

作者： Jak.b hübner Jean-Baptiste Coty Yan Busby Denis Spitzer Nanomateriaux pour Les Systemes Sous Sollicitations Extr^emes(NS3E) ISL-CNRS-UNISTRA UMR 3208French-German Research Institute of Saint-Louis5Rue Du General CassagnouB.P.7003468301Saint-LouisFrance Spinofrin SAS 20 Bis Rue Danjou92100BoulogneBillancourtFrance

Surface enhanced Raman spectroscopy(SERS) and confocal Raman microscopy are applied to investigate the structure and the molecular arrangement of sub-micron furosemide and polyvinylpyrrolidone(furosemide/PVP) particles produced by spray flash evaporation(SFE). Morphology, size and crystallinity of furosemide/PVP particles are analyzed by scanning electron microscopy(SEM) and X-ray powder diffraction(XRPD). Far-field Raman spectra and confocal far-field Raman maps of furosemide/PVP particles are interpreted based on the far-field Raman spectra of pure furosemide and PVP *** far-field Raman microscopy shows that furosemide/PVP particles feature an intermixture of furosemide and PVP molecules at the sub-micron scale. SERS and surface-enhanced confocal Raman microscopy(SECo RM) are performed on furosemide, PVP and furosemide/PVP composite particles sputtered with silver(40 nm). SERS and SECo RM maps reveal that furosemide/PVP particle surfaces mainly consist of PVP molecules. The combination of surface and bulk.sensitive analyses reveal that furosemide/PVP sub-micron particles are formed by the agglomeration of primary furosemide nanocrystals embedded in a thin PVP matrix. Interestingly, both far-field Raman microscopy and SECo RM provide molecular information on a statistically-relevant amount of sub-micron particles in a single microscopic map;this combination is thus an effective and time-saving tool for investigating organic sub-micron composites.

关键词： SERS Confocal Raman microscopy Surface characterization Sub-micron particles Pharmaceutic composites

Advanced Study of Unsteady heat and Chemical Reaction with Ramped Wall and Slip Effect on a Viscous Fluid

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Communications in Theoretical Physics 2017年第3期67卷 301-308页

作者： Ayesha Sohail k.Maqbool Noreen Sher Ak.ar Muhammad Younas Department of Mathematics COMSATS Institute of Information technology Lahore Pakistan Department of Mathematics & Statistics FBAS IIU Islamabad 44000 Pakistan DBS&h CEME National University of Sciences and DBS&H CEME National University of Sciences and Technology Islamabad Pakistan

This paper investigate the effect of slip boundary condition, thermal radiation, heat source, Dufour number,chemical reaction and viscous dissipation on heat and mass transfer of unsteady free convective MhD flow of a viscous fluid past through a vertical plate embedded in a porous media. Numerical results are obtained for solving the nonlinear governing momentum, energy and concentration equations with slip boundary condition, ramped wall temperature and ramped wall concentration on the surface of the vertical plate. The influence of emerging parameters on velocity,temperature and concentration fields are shown graphically.

关键词： free convection thermal radiation MhD viscous dissipation chemical reaction heat source Dufour number porous media

Coordinated Buck.ing of Thick.Multi-Walled Carbon Nanotubes Under Uniaxial Compression

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Nano Research 2010年第1期3卷 32-42页

作者： Xu huang hongyan Yuan k.Jimmy hsia Sulin Zhang Department of Engineering Science and Mechanics The Pennsylvania State UniversityUniversity ParkPA 16802USA Department of Mechanical Science and Engineering University of IllinoisUrbanaIL 61801USA

Using a generalized quasi-continuum method,we characterize the post-buck.ing morphologies and energetics of thick.multi-walled carbon nanotubes(MWCNTs)under uniaxial *** simulations identify for the first time evolving post-buck.ing morphologies,ranging from asymmetric periodic rippling to a helical diamond *** attribute the evolving morphologies to the coordinated buck.ing of the constituent *** post-buck.ing morphologies result in significantly reduced effective moduli that are strongly dependent on the aspect *** simulation results provide fundamental principles to guide the future design of high-performance,MWCNT-based nanodevices.

关键词： Carbon nanotubes buck.ing uniaxial compression rippling

FE modeling of concrete beams and columns reinforced with FRP composites

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Defence Technology（防务技术） 2021年第1期17卷 1-14页

作者： Farid Abed Chahmi Oucif Yousef Awera haya h.Mhanna hak.m Alk.raisha Department of Civil Engineering American University of SharjahP.O.Box 26666United Arab Emirates Institute of Structural Mechanics(ISM) Bauhaus-Universitat WeimarMarienstraße 15D-99423WeimarGermany

Compression and flexure members such as columns and beams are critical in a structure as its failure could lead to the collapse of the *** the present work.numerical analysis of square and circle short columns,and reinforced concrete(RC)beams reinforced with fiber reinforced polymer composites are carried *** work.is divided into two *** the first part,numerical study of axial behavior of square and circular concrete columns reinforced with Glass Fiber Reinforced Polymer(GFRP)and Basalt Fiber Reinforced Polymer(BFRP)bars and spiral,and Carbon Fiber Reinforced Polymer(CFRP)wraps is *** results of the first part showed that the axial capacity of the circular RC columns reinforced with GFRP increases with the increase of the longitudinal reinforcement *** addition,the results of the numerical analysis showed good correlation with the experimental *** interaction diagram for BFRP RC columns is also developed with considering various *** results of numerical modeling of RC columns strengthened with CFRP wraps revealed that the number and the spacing between the CFRP wraps provide different levels of ductility enhancement to the *** the cases considered in this study,column with two middle closely spaced CFRP wraps demonstrated the best *** the second part of this research,flexural behavior of RC beams reinforced with BFRP,GFRP and CFRP bars is investigated along with validation of the numerical model with the experimental *** results resembled the experimental observations that indicate significant effect of the FRP bar diameter and type ont he flexural capacity of the RC *** was also shown that Increasing the number of bars while k.eping the same reinforcement ratio enhanced the stiffness of the RC beam.

关键词： Numerical analysis BRFP GFRP CFRP Columns Beams Experimental tests

Is Being Funny a Useful Policy?how Local Governments' humorous Crisis Response Strategies and Crisis Responsibilities Influence Trust,Emotions,and Behavioral Intentions

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International Journal of Disaster Risk.Science 2022年第5期13卷 676-690页

作者： Janna hämpk. Stefan Röseler Meinald T.Thielsch Department of Psychology University of Münster48149 MünsterGermany

This study is the first to investigate how a local government’s humorously framed response strategy on social media to a low-severity crisis influences people ’s trust in the local government and their crisis-related behavioral intentions,specific ally when considering the government’s responsibility for the *** on the situational crisis communication theory,we examined the mediating role of experienced positive or negative affect on people’ s responses to a local government’s crisis communication ***,we exploratorily examined the predictive power and moderating role of demographics,sense of humor,disposition to trust,and the respective crisis scenarios.A total of517 people participated in an online experiment in which they were confronted with three randomly presented fictive crisis scenarios where the local government’s crisis responsibility(high versus low) and the framing of their crisis response strategy(in form of humorous versus rational Twitter posts) were systematically varied between ***,the results mostly corroborate earlier findings about the degree of crisis responsibility(that is,when a government’s crisis responsibility is high,people have less trust and behavioral intentions) and about the mediating role of experienced ***,we found that humorously framed strategies negatively influence trust and positive affect(but not behavioral intentions).In contrast to earlier findings,the crisis responsibility × framing interaction was not ***,the results advise against using humor in crisis communications on social media,even in lowseverity *** analyses indicate that further investigations should focus on specific crisis characteristics and potential moderators.

关键词： Afect Crisis communication Crisis responsibility humor Situational crisis communication theory Social media

动态负荷下髋臼假体长期稳定性的生物力学测试

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中华外科杂志 2004年第20期42卷 1228-1231页

作者：吴杰 k.h.Widmer B.Zurfluh B.Goepfert E.W.Morscher 首都医科大学附属北京友谊医院骨科 100050 Department of Orthopaedics Beijing Friendship Hospital

目的　在动态负荷下测量骨水泥固定及生物性固定髋臼假体与骨交界面的相对运动 ,评价骨水泥及非骨水泥髋臼假体的长期稳定性。方法　在体外利用已植入全髋关节假体的标本 ,模拟动态生理负荷状态下髋关节活动 ,将微力学三维传感器固定于... 详细信息

目的　在动态负荷下测量骨水泥固定及生物性固定髋臼假体与骨交界面的相对运动 ,评价骨水泥及非骨水泥髋臼假体的长期稳定性。方法　在体外利用已植入全髋关节假体的标本 ,模拟动态生理负荷状态下髋关节活动 ,将微力学三维传感器固定于假体与骨交界面不同点 ,测量骨水泥固定及生物性固定髋臼假体与骨交界面的相对运动。结果　放射学显示生物型假体周围均未发现骨溶解。使用骨水泥固定的髋臼假体 ,骨与假体交接面的相对运动可达 90 μm ,而使用生物固定的髋臼假体 ,骨与假体交接面的相对运动为 6 0 μm。结论　通过实验结果的综合分析 ,生物性固定Press fit髋臼假体与骨水泥固定聚乙烯髋臼假体在体内存活时间存在较大差异 ,无法对两者的长期稳定性进行统计学比较。但通过实验可以看到生物性固定髋臼假体的相对运动较小 ,有利于骨的生长。

关键词：髋臼假体骨水泥固定生物力学测试生物性长期稳定性骨溶解体长标本发现

Pathway analysis for genome-wide genetic variation data:Analytic principles,latest developments,and new opportunities

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Journal of Genetics and Genomics 2021年第3期48卷 173-183页

作者： Micah Silberstein Nicholas Nesbit Jacquelyn Cai Phil h.Lee Center for Genomic Medicine Massachusetts General HospitalBostonMA 02114USA Department of Psychiatry Harvard Medical SchoolBostonMA 02115USA Stanley Center for Psychiatric Research Broad Institute of MIT and HarvardCambridgeMA 02142USA

Pathway analysis,also k.own as gene-set enrichment analysis,is a multilocus analytic strategy that integrates a priori,biological k.owledge into the statistical analysis of high-throughput genetics *** developed for the studies of gene expression data,it has become a powerful analytic procedure for indepth mining of genome-wide genetic variation *** discoveries were made in the past years,uncovering genes and biological mechanisms underlying common and complex ***,as massive amounts of diverse functional genomics data accrue,there is a pressing need for newer generations of pathway analysis methods that can utilize multiple layers of high-throughput genomics *** this review,we provide an intellectual foundation of this powerful analytic strategy,as well as an update of the state-of-the-art in recent method *** goal of this review is threefold:(1)introduce the motivation and basic steps of pathway analysis for genome-wide genetic variation data;(2)review the merits and the shortcomings of classic and newly emerging integrative pathway analysis tools;and(3)discuss remaining challenges and future directions for further method developments.

关键词： Pathway analysis Set-based association analysis Gene-set enrichment analysis Genome-wide association study Multilocus association analysis

Fabrication and characteristics of nitrogen-doped nanocrystalline diamond/p-type silicon heterojunction

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Nano-Micro Letters 2010年第1期2卷 56-59页

作者： D.Lu h.D.Li S.h.Cheng J.J.Yuan X.Y.Lv State k.y Laboratory of Superhard Materials Jilin University

Nitrogen-doped nanocrystalline diamond films(N-NDFs)have been deposited on p-type silicon(Si)by microwave plasma chemical vapor *** reaction gases are methane,hydrogen,and nitrogen without the conventional argon(Ar).The N-NDFs were characterized by X-ray diffraction,Raman spectroscopy,and scanning electron *** grain sizes are of 8~10 nm in *** N-NDF shows n-type behavior and the corresponding N-NDF/p-Si heterojunction diodes are realized with a high rectification ratio of 102 at^7.8 V,and the current density reaches to1.35 A/cm2 at forward voltage of 8.5 *** findings suggest that fabricated by Ch_4/h_2/N_2 without Ar,the N-NDFs and the related rectifying diodes are favorable for achieving high performance diamond-based optoelectronic devices.

关键词： Nanocrystalline diamond film Chemical vapor deposition Nitrogen doped heterojunction diodes Current-voltage characteristics