Abstract: The influence of the optical properties of the core and shell materials on the LSPR strength for nanoshell particles are calculated based on the quasi-static functions. The results show that for particles with the metallic shell and gained core, the desired real and imaginary parts of dielectric function are positive and negative respectively, and both the absolute values increase as the volume fraction of shell material increases while the LSPR strength is strongest. For particles with metallic material core and gained material shell, in order to produce the maximum LSPR strength, gain medium can have two kinds of choices, one is that the real part of the dielectric function is positive and the imaginary part is negative and both the absolute values are relatively large, the other is the real part and imaginary part of gained dielectric function are negative and their absolute values are relatively small, which small change may lead to mobile resonance wavelength greatly.
Abstract: The present study report two types of ultra-thin shellac fibers that were fabricated using a traditional single fluid electrospinning and a modified coaxial electrospinning. Ethanol was exploited as the solvent of shellac and also a sheath fluid of the coaxial process. A camera was used to observe the electrospinning processes and scanning electron microscope was taken to investigate the prepared shellac nanofibers. A single fluid electrospinning of 64% (w/v) shellac solutions not only clogged the spinneret now and then, but also resulted in fibers with a spindles-on-a-string morphology under a flow rate of 1.0 mL/h and an applied voltage of 12 kV. In sharp contrary, a coaxial electrospinning of 80% (w/v) shellac solutions (under a sheath and core flow rate of 0.2 and 0.8 mL/h, respectively, and an applied voltage of 12 kV) furnished linear nanofibers with an average diameter of 740 ± 60 nm. With the same outflows from the nozzles of spinneret, the ultrathine nanofibers from the modified coaxial process surpassed those from the single fluid process in terms of fibers’ morphology and size. The modified coaxial process described here expands the capability of electrospinning process and opens a new way to obtain thinner nanofibers with fine structural uniformity.
Abstract: The cement-free binding material, namely geopolymer, is a novel binding material made from solid waste such as fly ash and slag activated by the alkali. In this research, orthogonal tests were carried out on 20 x 20 x 20mm cube paste specimens cured at room temperature to explore the rules of influence factors according to the compressive strength for 3d, 7d and 28d. The results revealed that the ratio of fly ash/slag is the most significant factor, the ratio of water/ (fly ash+ slag), the modulus of alkali activator and the dosage of desulfurized gypsum also play great role in strength development of the binder. The compressive strength of the specimens can be obtained to 65.0 MPa and 51.21MPa at maximum for 28d when the ratios of fly ash/slag are 30/70 and 40/60 respectively.
Abstract: Styrofoam (EPS) lightweight concrete, a new type of lightweight aggregate concrete, whose superior thermal performance and remarkable economic benefit earns more and more attention from the engineering. Adding nanoSiO2 into it can improve the frost resistance of EPS lightweight concrete, so that it can improve the microstructure and mechanical properties of concrete. The research on the nanomaterials has the vital significance to the frost resistance of EPS lightweight concrete. The wide application of this technology will greatly promote the development of construction industry, and has very important engineering practical value and social economic benefits.
Abstract: Endohedral metallofullerenes were prepared by DC arc discharge method with yttrium oxide and yttrium-nickel alloy as metal source, respectively. Mass spectroscopy and high-performance liquid chromatography analyses evidence that yttrium-nickel alloy has advantages over yttrium oxide in higher yield of soot, more species and higher yield of soluble metallofullerenes.
Abstract: In recent years, with the excellent mechanical properties, good thermal conductivity and electrical conductivity and optical properties, Graphene is widely used in many fields such as chemistry, physics and material science .The preparation of graphene have had a very big progress.This paper reviews the chemical preparation methods of graphene and the application of Graphene / Chitosan composite.Then we point out the outlook of the application of the composite materials graphene with other biological macromolecules which are similar with chitosan.
Abstract: Combined with the heat-resistant concrete needed for a company combustor, based on the availability of local raw materials, the orthogonal test was used, then by the variance analysis and range analysis, the components of the heat-resistant concrete which could meet the technical requirements of the project were selected. Engineering application results showed: the components of the concrete could meet technical indicators for the engineering application, and effectively reduced the cost of production of heat-resistant concrete.
Abstract: Based on the technical performance index of heat-resistant concrete in a project, combined with local material performance and market supply and demand, based on the mix ratio for the concrete of strength C25, five factors as cementitious materials, admixtures, coarse aggregate, fine aggregate, admixtures were selected, every factor selected two levels, by orthogonal experiments, based on range theory, the heat-resistant concrete components that were the most suitable for the project were selected, and provided a research base for further preparation of different strength grade heat-resistant concrete.
Abstract: In order to explore the enhancing method of rice straw based composites, glass fiber (GF) was introduced into the preparation of composites of poly (vinyl alcohol) (PVA) and rice straw slice (RSS). The tensile performances and hardness of composites were characterized. Results showed that GF had obvious enhancing role on PVA/RSS composites. The tensile strength of the composites first increased and then decreased with increasing GF amount. When the mass ratio of RSS, PVA and GF was 20:15:7, the composite reached its maximum strength of 23.45 MPa, which increased by 1.49 times compared to the composites without GF. The strength at tensile break of composites increased with the increase of GF amount. The maximum of strength at tensile break was 23.12 MPa when GF amount was 9 g. The stretch of composites first increased and then decreased with increasing GF amount. The addition of GF had no effect on the hardness of composites.
Abstract: Carbon nanotubes (CNTs) doped TiO2/glass fiber reinforced plastics (GRP) hybrid materials with different TiO2 and CNTs contents were prepared by first step sol-gel and then hand lay-up method, using modified CNTs doped tetrabutyl titanate as precursor. The results showed that high TiO2 and CNTs contents obtained GRP with high temperature stability and high electrical conductivity, but slowed down the solidification process of epoxy resin to obtain GRP.