The Effect of Core Eccentricity on the Structural Behavior of Concrete Tall Buildings

The main purpose of this paper is to investigate the effect of core eccentricity on the structural behavior of concrete tall buildings.Concrete buildings of 55 floors with plan dimensions 48.0×48.0 m2 were investigated.Three cases of main core locations are studied:centric(A),eccentric by one sixth(B)and one third(C)of building width.The three-dimensional finite element method has been used in conducting structural analysis through ETABS software.Gravity and lateral(wind and seismic)loadings are applied to all building cases.It has been concluded that the core location is the prime parameter governing the structural behavior of tall buildings.Although the first two cases(A,B)have acceptable and similar structural behaviors conforming to code limits,in the third case(C),the building behavior came beyond code limits.The author introduced remedial action by adding two secondary cores in the opposite direction of the main core(C-R)to restore the building behavior to the code limits.The results of this action were satisfactory.

One-dimensional ZnS-based Hetero-,Core/shell and Hierarchical Nanostructures

A focus of the current nanotechnology has shifted from routine fabrication of nanostructures to designing functional electronic devices and realizing their immense potentials for applications. Due to infusion of multi-functionality into a single system, the utilization of hetero-, core/shell and hierarchical nanostructures has become the key issue for building such devices. ZnS, due to its direct wide bandgap, high index of refraction, high transparency in the visible range and intrinsic polarity, is one of the most useful semiconductors for a wide range of electronics applications. This article provides a dense review of the state-of-the-art research activities in one-dimensional （1D） ZnS-based hetero-, core/shell and hierarchical nanostructures. The particular emphasis is put on their syntheses and applications.

Hierarchical Carbon Microtube@Nanotube Core-Shell Structure for High-Performance Oxygen Electrocatalysis and Zn-Air Battery

Zinc-air batteries(ZABs)hold tremendous promise for clean and efficient energy storage with the merits of high theoretical energy density and environmental friendliness.However,the performance of practical ZABs is still unsatisfactory because of the inevitably decreased activity of electrocatalysts when assembly into a thick electrode with high mass loading.Herein,we report a hierarchical electrocatalyst based on carbon microtube@nanotube core-shell nanostructure(CMT@CNT),which demonstrates superior electrocatalytic activity for oxygen reduction reaction and oxygen evolution reaction with a small potential gap of 0.678 V.Remarkably,when being employed as air-cathode in ZAB,the CMT@CNT presents an excellent performance with a high power density(160.6 mW cm^−2),specific capacity(781.7 mAhgZn^−1)as well as long cycle stability(117 h,351 cycles).Moreover,the ZAB performance of CMT@CNT is maintained well even under high mass loading(3 mg cm−2,three times as much as traditional usage),which could afford high power density and energy density for advanced electronic equipment.We believe that this work is promising for the rational design of hierarchical structured electrocatalysts for advanced metal-air batteries.

Fabrication of silica-based ceramic cores with internal lattice structures by stereolithography

Ceramic cores are widely used in investment casting,and ideal properties of cores are essential for high-quality castings.Under the circumstances requiring thick cores,solid cores are likely to encounter deformation and cracking defects due to the accumulation of shrinkage.Therefore,with the superiority of ceramic stereolithography in producing complex ceramic parts,hollow cores with lattice structures were designed and fabricated.The dimensional accuracy and properties of the green and sintered bodies were evaluated.Results show the dimensional accuracy of sintered cores is controlled within±0.25 mm benefited from the precise green bodies.The mechanical properties are not obviously deteriorated.The bending strength reaches 11.94 MPa at room temperature and 12.87 MPa at 1,500℃ with a creep deformation of 0.345 mm.Furthermore,casting verifications prove that the hollow cores meet the requirements of investment casting.Smooth casting surfaces are obtained,at the same time,the core-removal efficiency is improved by over 3 times.

On the core structure and mobility of the〈100 〉{010} and〈100 〉 {01■} dislocations in B2 structure YAg and YCu

Dislocations are thought to be the principal mechanism of high ductility of the novel B2 structure intermetallic compounds YAg and YCu.In this paper, the edge dislocation core structures of two primary slip systems 〈100〉{010} and 〈100〉{01^-1} for YAg and YCu are presented theoretically within the lattice theory of dislocation.The governing dislocation equation is a nonlinear integro-differential equation and the variational method is applied to solve the equation.Peierls stresses for 〈100〉{010} and 〈100〉{01^-1} slip systems are calculated taking into consideration the contribution of the elastic strain energy.The core width and Peierls stress of a typical transition-metal aluminide NiAl is also reported for the purpose of verification and comparison.The Peierls stress of NiAl obtained here is in agreement with numerical results,which verifies the correctness of the results obtained for YAg and YCu.Peierls stresses of the 〈100〉{01^-1} slip system are smaller than those of 〈100〉{010} for the same intermetallic compounds originating from the smaller unstable stacking fault energy.The obvious high unstable stacking fault energy of NiAl results in a larger Peierls stress than those of YAg and YCu although they have the same B2 structure.The results show that the core structure and Peierls stress depend monotonically on the unstable stacking fault energy.

EXTENDED CORE STRUCTURE OF DISSOCIATED EDGE DISLOCATIONS IN FCC CRYSTALS WITH CONSIDERATION OF DISCRETENESS

The extended core structure of the dissociated edge dislocation in Al, Au, Ag, Cu and Ni is determined within lattice theory of dislocation. The 2D dislocation equation governing the displacements is coupled by the restoring forces that are determined by the parameterization of the generalized stacking fault energies. The Ritz variational method is presented to solve the dislocation equation and the trial solution is constituted by two arctan-type functions with two undetermined parameters. The core widths of partial dislocations are wider than that obtained in generalized Peierls-Nabarro model due to the consideration of discreteness of crystal.

Development of Composite Cellular Cores for Sandwich Panels Based on Folded Polar Quadra-Structures

An idea to develop a family of cellular cores for sandwich panels using a technology of prepreg folding is presented.Polar folded quadra-structures are regarded as a geometric basis for these cores whose standard fragment has the fourth degree of axial symmetry.The classification of the polar structures are described and a method of various quadra-structure synthesis is developed.A possibility to provide high strength of the structure due to preservation of faces reinforcement pattern is presented.Arrangement of the plane core on a bi-curvature surface is also introduced.Besides,provision of isotropy of the core in two or three directions are described.Finally,examples of cellular folded cores manufactured from basalt reinforced plastic are demonstrated.

Synthesis and Characterization of Fluorine-containing Polyacrylate Emulsion with Core-Shell Structure

包含氟的符号的 polyacrylate 共聚物乳剂被一个种子乳剂聚合方法，在甲基， methacrylate (MMA ) 和丁基 acrylate (BA ) 作为包含氟的符号的单体被用作主要单体和 hexafluorobutyl methacrylate (HFMA ) 综合。结构和性质被 Fourier 变换描绘红外线的光谱(英尺红外) ，传播电子显微镜学(TEM ) ，粒子尺寸分析， X 光检查光电子光谱学(XPS ) ，接触角度(CA ) ，微分扫描热量测定(DSC ) 和 thermogravimetry (TG ) 分析。FTIR 和 TEM 结果证明 HFMA 有效地涉及乳剂 copolymerization，并且形成的乳剂粒子让核心壳结构和一个狭窄的粒子缩放分发。XPS 和 CA 分析表明氟的符号的坡度集中在富于氟的符号和在一个方面恐水病的更多的包含氟的符号的乳剂电影的深度侧面存在。DSC 和 TG 分析也证明清楚的核心壳结构在包含氟的符号的乳剂粒子存在，并且他们的电影比没有氟的符号的乳剂的显示出更高热的稳定性。

Sensitivity of Tropical Cyclone Intensification to Inner-Core Structure

In this study, the dependence of tropical cyclone （TC） development on the inner-core structure of the parent vortex is examined using a pair of idealized numerical simulations. It is found that the radial profile of inner-core relative vorticity may have a great impact on its subsequent development. For a system with a larger inner-core relative vorticity/inertial stability, the conversion ratio of the diabatic heating to kinetic energy is greater. Furthermore, the behavior of the convective vorticity eddies is likely modulated by the system-scale circulation. For a parent vortex with a relatively higher inner-core vorticity and larger negative radial vorticity gradient, convective eddy formation and radially inward propagation is promoted through vorticity segregation. This provides a greater potential for these small-scale convective cells to self-organize into a mesoscale inner-core structure in the TC. In turn, convectively induced diabatic heating that is close to the center, along with higher inertial stability, efficiently enhances system-scale secondary circulation. This study provides a solid basis for further research into how the initial structure of a TC influences storm dynamics and thermodynamics.

Synthesis of Ag@Al_2O_3 Core-shell Structure Nanoparticles and Their Enhancement Effect on Dielectric Properties for Ag@Al_2O_3/Polyimide Nanocomposites

A novel core-shell structure Ag@Al2O3 nano-particles were synthesized and doped into polyimide as conductive fillers to prepare the composite films with high dielectric properties and low dielectric loss. The morphology and structures of the Ag@Al2O3 nano-particles were characterized by transmission electron microscopy （TEM）, X-ray diffraction （XRD）, and UV-visible spectroscopy. All the results proved that the Ag@Al2O3 nano-parficles had a typical core-shell structure, for the Ag particles were coated by Al2O3 shell and the average sizes ofAg@Al2O3 particles were between 30 to 150 nm. The as-prepared Ag@Al2O3 nanoparticles were doped into the polyimide with different mass fractions to fabricate the Ag@Al2O3/PI composite films via in-situ polymerization process. SEM analysis of composite films showed that the Ag@Al2O3 nano- particles homogeneously dispersed in polyimide matrix with nanoseale. As dielectric materials for electronic packaging systems, the Ag@Al2O3/PI composites exhibited appropriate mechanical properties and erthaneed dielectric properties, including greatly enhanced dielectric constant and just a slight increase in dielectric loss. These improvements were attributed to the core-shell structure of fillers and their fine dispersion in the PI matrix.

Photochemical synthesis of bimetallic Au-Ag nanoparticles with “core-shell” type structure by seed mediated catalytic growth

The colloidal Au core/Ag shell structure composite nanoparticles were synthesized in PEG-acetone solution by photochemical route. The monodispersed Au nanoparticles with average diameter of 3.9 nm were used as growth seeds. The optical property of colloids and the sizes of composite nanoparticles were characterized when the molar ratio of Au to Ag ranges from 4∶1 to 1∶4. The results show that a composite nanoparticle structure similar to strawberry shape is formed at the molar ratio of Au to Ag from 4∶1 to 1∶1; the composite nanoparticles consisting of a core of Au and shell of Ag were generated at the 1∶4 molar ratio, having a striking feature of forming (interconnected) network structure.

Detecting the core of a network by the centralities of the nodes

Many networks exhibit the core/periphery structure.Core/periphery structure is a type of meso-scale structure that consists of densely connected core nodes and sparsely connected peripheral nodes.Core nodes tend to be well-connected,both among themselves and to peripheral nodes,which tend not to be well-connected to other nodes.In this brief report,we propose a new method to detect the core of a network by the centrality of each node.It is discovered that such nodes with non-negative centralities often consist in the core of the networks.The simulation is carried out on different real networks.The results are checked by the objective function.The checked results may show the effectiveness of the simulation results by the centralities of the nodes on the real networks.Furthermore,we discuss the characters of networks with the single core/periphery structure and point out the scope of the application of our method at the end of this paper.

Effect of milling process on the core-shell structures and dielectric properties of fine-grained BaTiO_3-based X7R ceramic materials

Fine-grained BaTiO3-based X7R ceramic materials were prepared and the effects of milling process on the core-shell structures and dielectric properties were investigated using scanning electron microscope, transmission electron microscope, and energy dispersive spectroscopy （EDS）. As the milling time extends, the dielectric constant of the ceramics increases, whereas the temperature coefficient of capacitance at 125℃ drops quickly. The changes in dielectric properties are considered relevant to the microstructure evolution caused by the milling process. Defects on the surface of BaTiO3 particles increase because of the effects of milling process, which will make it easier for additives to diffuse into the interior grains. As the milling time increases, the shell region gets thicker and the core region gets smaller; however, EDS results show that the chemical inhomogeneity between grain core and grain shell becomes weaker.

Reduced-temperature ordering of FePt nanoparticle assembled films by Fe30Pt70/Fe3O4 core/shell structure

In this paper, Fe30Pt70/Fe3O4 core/shell nanoparticles were synthesized by chemical routine and the layered polyethylenimine （PEI）-Fe30Pt70/Fe3O4 structure was constructed by molecule-mediated self-assembly technique. The dimension of core/shell structured nanoparticles was that of 4nm core and 2 nm shell. After annealing under a flow of forming gas （50%Ar2＋30%H2） for 1 h at or above 400℃, the iron oxide shell was reduced to Fe and diffused to Pt-rieh core, which leaded to the formation of L1. phase FePt at low temperature. The x-ray diffraction results and magnetic properties measurement showed that the chemical ordering temperature of Fe30Pt70/Fe3O4 core/shell nanoparticles assembly can be reduced to as low as 400℃. The sample annealed at 400℃ showed the eoereivity of 4KOe with the applied field of 1.5T. The core/shell structure was suggested to be an effective way to reduce the ordering temperature obviously.

Shell-driven Fine Structure Transition of Core Materials in Co@Au Core-shell Nanoparticles

Co@Au core shell nanoparticles(NPs) of different shell thicknesses were fabricated by a combination of the displacement process and the reduction-deposition process in a microfluidic reactor. The effect of the shell thickness on the fine structures(local atom arrangement) of core materials was investigated by X-ray Absorption Near Edge Structure(XANES) and Extended X-ray Absorption Fine Structure(EXAFS).The results indicate that the shell thickness affects the fine structure of the core materials by causing atomic re-arrangement between the hexagonal close pack(hcp) and the face centered cubic(fcc) structure, and forming Co-Au bonds in the core-shell interface.

Core-shell structured 1,4-benzoquinone@TiO_2 cathode for lithium batteries

Organic carbonyl compounds are considered as promising candidates for lithium batteries due to theirhigh capacity and environmental friendliness, However, they suffer from serious dissolution in the elec-trolyte, leading to fast capacity decay. Here we report core-shell structured 1,4-benzoquinone@titaniumdioxide （BQ@TiO2） composite as cathode for lithium batteries. The composite cathode can deliver a highdischarge capacity of 441.2 mA h/g at 50 mA/g and a high capacity retention of 80.7% after 100 cycles. Thegood cycling performance of BQ@TiO2 composite can be attributed to the suppressed dissolution of BQ,which results from the physical confinement effect of Ti02 shell and the strong interactions between BQand Ti02. Moreover, the combination of ex situ infrared spectra and density functional theory calculationsreveals that the active redox sites of BQ are carbonyl groups. This work provides an alternative way tomitigate the dissolution of small carbonyl compounds and thus enhance their cycling stability.

Immobilization of metalloporphyrins on CeO_2@SiO_2 with a core-shell structure prepared via microemulsion method for catalytic oxidation of ethylbenzene

Ce O2@Si O2 core-shell nanoparticles were prepared by microemulsion method, and metalloporphyrins were immobilized on the Ce O2@Si O2 core-shell nanoparticles surface via amide bond. The supported metalloporphyrin catalysts were characterized by N2 adsorption-desorption isotherm(BET), scanning electron microscopy(SEM), transmission electron microscopy(TEM), X-ray diffraction(XRD), ultraviolet and visible spectroscopy(UV-Vis), and Fourier transform infrared spectroscopy(FT-IR). The results show that the morphology of Ce O2@Si O2 nanoparticles is core-shell microspheres with about 30 nm in diameter, and metalloporphyrins are immobilized on the Ce O2@Si O2 core-shell nanoparticles via amide bond. Especially, the core-shell structure contains multi Ce O2 core and thin Si O2 shell, which may benefit the synergistic effect between the Ce O2 core and the porphyrin anchored on the very thin Si O2 shell. As a result, this supported metalloporphyrin catalysts present comparably high catalytic activity and stability for oxidation of ethylbenzene with molecular oxygen, namely, ethylbenzene conversion remains around 12% with identical selectivity of about 80% for acetophenone even after six-times reuse of the catalyst.

On the Dynamics of Vortex Filaments and Their Core Structure

We give a brief review of the asymptotic theory of slender vortex filaments with emphases on (i) the choices of scalings and small parameters characterizing the physical problem,(ii) the key steps in the formulation of the theory and (iii) the assumptions and/or restrictions on the theory of Callegari and Ting (1978).We present highlights of an extension of the 1978 asymptotic theory:the analyses for core structures with axial variation.Making use of the physical insights gained from the analyses,we present a new derivation of the evolution equations for the core structure.The new one is simpler and straightforward and shows the physics clearly.

Comparative studies in method for stratigraphical structure measurement of ice cores: Identification of cloudy bands

Cloudy bands are typical stratigraphic structure in deep ice core. Detailed recording of cloudy bands is important for dating of ice core since pair of series cloudy band and clear layer is corresponds to annual layer and it sometimes corresponds to volcanic ash layer. We developed two type scanners, transmitted light method and laser tomograph method for the stratigraphic study. Measurements were carried out for NGRIP deep ice core, which containing many cloudy bands, using the two type scanners and digital camera. We discussed about the possibility of identification of cloudy bands by each method and about advantage and disadvantage of measurements and their results.

Delamination Testing of AlSi10Mg Sandwich Structures with Pyramidal Lattice Truss Core made by Laser Powder Bed Fusion

Sandwich structures possess a high bending stiffness compared to monolithic structures with a similar weight.This makes them very suitable for lightweight applications,where high stiffness to weight ratios are needed.Most common manufacturing methods of sandwich structures involve adhesive bonding of the core material with the sheets.However,adhesive bonding is prone to delamination,a failure mode that is often difficult to detect.This paper presents the results of delamination testing of fully additive manufactured(AM)AlSi10Mg sandwich structures with pyramidal lattice truss core using Laser Powder Bed Fusion(LPBF).The faces and struts are 0.5 mm thick,while the core is 2 mm thick.The inclination of the struts is 45°.To characterise the bonding strength,climbing drum peel tests and out-of-plane tensile tests are performed.Analytical formulas are derived to predict the expected failure loads and modes.The analytics and tests are supported by finite element(FE)calculations.From the analytic approach,design guidelines to avoid delamination in AM sandwich structures are derived.The study presents a critical face sheet thickness to strut diameter ratio for which the structure can delaminate.This ratio is mainly influenced by the inclination of the struts.The peel tests resulted in face yielding,which can also be inferred from the analytics and numerics.The out-of-plane tensile tests didn’t damage the structure.