Papers by Keyword: Hollow

Abstract: We successfully developed a facile synthetic way to 3D hollow HAp microspheres. We used Ca (NO₃)₂ and (NH₄)₃PO₄ as materials, hyperbranched Gemini surfactant (PCD) as template.We used some techniques to characterize the products,such as X-ray powder diffraction (XRD), Fourier transform infrared spectroscope (FT-IR), Scanning electron microscopy (SEM) and Thermal gravimetric analysis (TG).The effects of the Gemini surfactant concentration on the morphology and crystal degree of the samples were analyzed.We proposed a possible growth of mechanism.The product morphology could vary from rod to hollow sphere by adjusting the template concentration.When the template concentration was low,ball-like hydroxyapatite preliminary formed.With increasing the template concentration,the crystal degree of products declined. While the spherical cluster composed of numbers of flake or needle architectures were appeared. The results show that when the mass fraction of template is 0.01%,we can product uniform well-defined hollow spherical hydroxyapatite with semidiameter about 1.5μm.

Abstract: Shear wall systems are the most commonly used lateral load resisting systems in high seismic zones because they provide significant lateral strength, stiffness, and deformation capacity. The work further investigates the seismic performance of different kinds of shear walls. Classified and brief comments about the seismic performance and the exist drawback of different kinds of shear walls and its application are conducted. Lastly, some useful suggestions and a new structure are proposed for the further research.

Abstract: Wide-Chord Hollow Fan Blade is One of the New Technologies Used in Aircraft Engines. in this Paper, the Modal Analysis Method is Used to Analyze the Influence of the Rib Number and the Rib Thickness to Wide-Chord Hollow Fan Blade Vibration Characteristics. the Result Shows that the Wide-Chord Hollow Fan Blades Greatly Improves the First-Order Vibration Frequency Compared with the Solid Blades, and the First-Order Vibration Frequency of the Wide-Chord Hollow Fan Blades is Reduced with the Increasing Rib Number which is Not Good for Vibration Elimination. the Wide-Chord Hollow Fan Blades’ Vibration Frequency Changes a Little when the Rib Number is Larger than Three. in Addition, the Rib Thickness has Smaller Effect on Wide-Chord Hollow Fan Blade.

Abstract: Hollow and hierarchical NiO nanosheets nanotubes were successfully prepared through a one-step solvothermal route followed by a thermal annealing treatment. The microstructure and chemical composition of Ni-precursor@PNT core-shell nanostructures and calcined NiO nanosheets nanotubes are investigated by SEM, TEM, TGA and XRD. The unique NiO nanosheets nanotubes show admirable electrochemical performance as an electrode material for supercapacitors owing to the hierarchically tubular structures and hollow interior.

Abstract: In this work, we prepared the sandwich-like carbon@SnO₂@carbon hollow spheres by templating against polystyrene spheres. The hollow spheres are characterized by means of scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD). The electrochemical performance as the anodes of lithium-ions batteries are studied by the cyclic voltammogram (CV) and galvanostatic discharge-charge voltage tests. Because of the interesting structure, the as prepared carbon@SnO₂@carbon hollow spheres deliver a reversible capacity of 492 mA h g^-1 after 50 cycles at a high current density of 400 mA g^-1.

Abstract: This work demonstrated an approach of oil/water (O/W) microemulsion on preparation of hollow spheres with mesopores in the shell, in which a cationic surfactant was used as structural directing agent, alkane molecule as mesopore-swelling agent and oil droplets. The morphology and pore architecture of the obtained hollow spheres were characterized by SEM, XRD, TEM and N₂ adsorption/desorption isotherms. Cubic (Ia3d) mesopores are present in the shell and provide open channels for mass transport in between the hollow core and outer environment. The obtained hollow spheres with cubic mesoporous shell possess the potential of being used as nanoreactor and nanocontainer in the fields of catalysis and drug delivery.

Abstract: Magnetic Fe₃O₄ nanobubbles surrounded by nanoparticles are prepared by adopting microwave assisted reflux method. The nanomagnetic particles surrounded by small beads like particles are fabricated by irradiating the prepaperd sample solutions by microwave radiations coupled with reflux method simultaneously at 90°C for 45 mins. The characterization of the prepared Fe₃O₄ particles are carried out by using x ray diffraction, scanning electron microscopy and transmission electron microscopy. The instrumentations shows the morphology that is thick walled bubble like with approximate diameter of about 300 nm to 400 nm surrounded by small nanoparticles of 5 nm to 30 nm in range. The particles are bubbles like and some broken bubbles showed that these might be hollow from inside.

Abstract: Marcoporous silica hollow microspheres were prepared by poly (acrylic acid)@poly (ethyleneglycol dimethacrylate-co-4-vinylpyridine) (PAA@P(EGDMA-co-VPy)) composite particles with raspberry-like structure as the template. P(EGDMA-co-VPy) and PAA microspheres were prepared by distillation precipitation polymerization respectively. The raspberry-like organic composite polymer particles were obtained through the self-assembly of PAA microspheres on P(EGDMA-co-VPy) microspheres. Then, Silica layer was coated on the composite particles with Stöber method in an alkaline environment. The marcoporous silica hollow microspheres were received after the calcination to remove the organic template. The diameter of the marcoporous silica hollow microspheres, hollow inner core and the pore size of silica layer was about 2.0 μm, 1.5 μm and 20-130 nm, respectively.

Abstract: Zinc oxide with spherical shaped and flower shaped morphology are prepared by simple one step solvothermal method. The product is subjected to characterization to investigate the morphology and size by using X ray diffraction , semi electron microscopy and transmission electron microscopy. The size of the prepared zinc oxide particle is in the range of 1 micrometer to 3 micrometers. The outer surface of the particles is not smooth but it is rough. The possible formation mechanism for the product is investigated that is further justified by means of structural characterization.

Abstract: This paper is based on the study of acoustic scattering classic RST, in which it was introduced the method of MRST (multichannel resonant scattering theory) to study the problem of interaction of acoustic waves normal incidence in environments consisting of a biphasic isotropic elastic matrix in which is inserted a fluid inclusion (cylindrical or spherical). Initially we implement the transition matrix S containing the mode n of the longitudinal (L) and transverse (T) of the wave in the elastic medium. The isolation of resonances characteristic of the fluid inclusion is done via the S-matrix factorization as a product of the matrix of soft bottoms no resonant matrix and resonances. To improve the localization of the resonances we undertake a study of the absolute phase in connection with MRST. A numerical simulation of cavity fluid (water) cylindrical and spherical copper in a matrix, showed the effectiveness of the absolute phase spectra for the exact determination of the resonances.