Advanced Materials Research Vols. 295-297

Abstract: A general sonochemical approach that allows for the facile, rapid synthesis of MSn(OH)₆ (M=Ba, Ca, Sr) one-dimension (1D) nanostructures has been developed. The resulting CaSn(OH)₆ products possessed a nanotubular structure, while SrSn(OH)6 and BaSn(OH)₆ showed nanowire-like structures. The as-synthesized MSn(OH)6 products were characterized by XRD, SEM and TEM techniques. The BaSn(OH)₆ nanowires, CaSn(OH)₆ nanotubes, and SrSn(OH)₆ nanowires share different growth mechanisms because they take different crystal structures. However, we found that for all the three materials, both the ultrasound irradiation and the presence of Na₂CO₃ in the synthetic procedure had an impact on the homogeneous nucleation and fast growth of 1D MSn(OH)₆ nanostructures. This approach represents a successful example for the fast construction of inorganic innovative nanostructures in the absence of any surfactants.

Abstract: We have used the sonochemical approach to synthesize single crystals CaCO₃ nanocrystals with various anisotropic shapes of such as, nanowires, nanosheets and unusually obtained nanoplates without using any template at room temperature. The complex interplay between crystallization processes and self-assembly resulting from spatial constrains has been investigated through studying the structural evolution of metastable intermediates synthesized. The impurity inducing crystallization has been proposed for a reasonable understanding of the novel crystallization pathway under the condition of sonication. Moreover, this approach is suitable to the anisotropic single crystals synthesis of other alkaline earth carbonates such as SrCO₃ and BaCO₃. It also gives a new demonstration of sonochemical effects on the crystallization and assembly of block building in the mesoscale.

Abstract: The multi-stage boom consisting of several booms is used in order to develop the aerial platform truck that can be used in a working radius that is higher and safe. Because the length increases compared with the width or the height of the structure, the intensity and rigidity are lowered along with the safety. Accordingly, a countermeasure is needed. Therefore, in this research, when designing of the high ground work difference Boom System, the safety the stress of the considered boom the analyze method and experimental method tries to be evaluated through the comparison. The finite-element analysis(FEA) compared the Strain value which is obtained through the resolution value and actual experiment by using the Ansys,that is the general purpose program, and proved this safety.

Abstract: The Ge mole fraction (x) of Si_1-xGe_x layer was described by the C-V technique for Schottkey contact of single heterojunction Si_1-xGe_x/Si, whose structure profile can be characterized by SEM image and EDS. Then the strained Si cap layer was grown on the Si_1-xGe_x/Si, and C-V technique was used to determine the carrier concentration and structure of double heterojunction Si/Si_1-xGe_x/Si. The change of the structure between Si_1-xGe_x/Si and Si/ Si_1-xGe_x/Si was also observed by this method.

Abstract: Brown Corundum Ash(BCA) was used to modify nylon 1212(PA1212), which is produced during the production of electric fused brown corundum alumina and will causes serous environmental pollution if it is not recycled. In order to improve the tribological property of PA1212 composites, Graphite, MoS₂ and PTFE were used. The composites were prepared by a twin-screw extruder through melt intercalation. The mechanical properties and the wear resistance of the PA1212/Brown Corundum Ash/graphite/MoS2/PTFE composite were studied. The shearing area of composite and the worn surfaces were examined by scanning electric microscope (SEM).

Abstract: Cubic structures having spherical pores ranged as BCC and FCC lattices are constructed to simulate the microstructures of cellular polymers with various relative densities. The Mooney-Rivlin strain energy potential model is adopted to characterize the hyperelasticity of the constituent solid from which the foams are made. Finite element analysis on the influences of the polymer hyperelasticity upon the macroscopic mechanical properties of the foams is carried out. Numerical results show that there is no obvious buckling plateau segment in the uniaxial compressive stress-strain curves of the regular spherical cell models as most low density foams have. Moreover, it is found that the initial tangent modulus is a power function of the foam’s relative density, and the index is smaller than 2 for lower relative density models, bigger than 2 for moderate relative density models, and closed to 2 for higher relative density models.

Abstract: Based on the experimental study of its constitutive relations, uses the ABAQUS finite element analysis software to simulation analyzes the three-dimensional static property of one type of polyurethane vibration isolators. The numerical analysis and experimental result demonstrate that the material constitutive model built by this method can describe the three-dimensional static mechanical property of the polyurethane isolator accurately. This method provides certain reference value for establishment of the constitutive relations of other types of polyurethane isolator.

Abstract: The traditional pure nickel coatings and the Ni-Co alloy coatings were prepared with the same parameters on the type 316L stainless steel substrates by utilizing two-ways pulse current electroplating method. And then, we used atomic force microscope (AFM) to observe their surface morphologies and structures and obtained their 3D images. The results of AFM showed that the Ni-Co alloy coating were superior to the traditional pure nickel coating on mechanical and tribological properties respects. For example, the surface of the Ni-Co alloy coating is smoother and even than that of the traditional pure nickel coating. Direct current (DC) and two-ways pulse current electroplating two methods were adopted respectively to prepare the Ni-Co alloy coatings. Followed we observed their surface morphologies by using AFM. The result showed that under the same experimental parameters the coating of the two-ways pulse current electroplating is superior to conventional DC electroplating coating in the surface morphology, grain size and microstructure and so on.

Abstract: Optical fiber array is a key component in the assembly of planar optical waveguide devices and enable greater channel counts than previously. However, assembling optical fiber array has been a challenge due to the stringent performance and reliability requirements posed by optical fiber communication applications. This paper investigates the causes of the failures involving the adhesive including: surface contamination, air entrapment, uneven curing, curing shrinkage; and thermal expansion coefficient mismatch.

Abstract: The oxygen transmission rate (OTR) of SiOx coated polyethylene terephthalate (PET) and biaxially oriented polypropylene (BOPP) affected by fine defects is discussed in this paper. With an ultrasonic AFM (UAFM), which is an advantageous to distinguishing tiny defects on/ in the deposited films, it is found that the OTR of the coated films is relevant to the morphology scanned by UAFM. Herein SiOx layers with a thickness in the order of nano-scale were fabricated in 13.56 MHz-radio frequency (RF) -plasma-enhanced chemical vapor deposition (PECVD). The monomer for the coating fabrication is hexamethyldisiloxane (HMDSO). Fourier transform inferred (FTIR) spectra of the deposited coating with a strong peak at 1062 cm^-1, corresponding to Si-O-Si stretching vibration, confirm the formation of SiOx coatings through PECVD. The higher OTR value of SiOx coated PET is consistence with defects on film surface and in the subsurface of coatings through UAFM. It obtains that the OTR value of the defect free SiOx coated film was reduced by ca. 89% compared with the defect existence SiOx coated PET.