Advanced Materials Research Vol. 901

Abstract: In this work, surface effects including surface elasticity and residual surface stress on the buckling of nanowires are theoretically investigated. Based on modified core-shell (MC-S) model, the effective elasticity incorporating surface elasticity effect of the nanowire is derived, and by using the generalized Young-Laplace equation the residual surface stress is accounted for. The ratio of critical load with and without surface effects are obtained for a nanowire loaded in uniaxial compression. Taking silver (Ag) nanowires as an example, the analyzed results demonstrate that the influence of surface effects on the critical load of buckling becomes more and more significant as the nanowire diameter decreases. Moreover, it is shown that the influence of residual surface stress on the critical load is more prominent than that of surface elasticity.

Abstract: Material strength is one of the most important factors in designing a building. For this reason, many structural steel manufacturers have been trying to develop it. In Korea, SM 570 is one high structural steel that has many merits such as longer span and reduction of construction cost for steel works. However, the fire resistance performance of H-section made of SM 570 has not been evaluated. Especially, in high-rise steel building that can be built with various joint systems like hinged to hinge, hinge to fixed, and fixed to fixed. However, the performance of fire resistant is limited. In this paper, to evaluate the fire resistance of H-section made of SM 570, the advanced fire design was conducted using regressive equation of the mechanical and thermal properties at high temperature, compared with those made of an ordinary structural steel, SS 400. The facts show that hinge to hinge had the lowest load bearing capacity at high temperature. Therefore, to keep the same fire resistance with other types boundary conditions, the more passive fire materials are required.

Abstract: Anisotropic wet etching of high resistivity silicon by TMAH for the fabrication of large area silicon radiation detectors is studied in this work. TMAH is widely applied in microelectronics and micromechanical fabrication etching low resistivity silicon, whereas the etching of high resistivity silicon was seldom studied by the industry. This work focused on the research of TMAH etching of high resistivity lager area silicon wafer aiming at its application in silicon radiation detector fabrication. We investigated the etching properties of TMAH of 4 inch (111) silicon wafers. Various parameters combinations were explored, such as TMAH solution concentration of 25wt%, 15wt% and 5wt%, and temperature of 95 °C, 90 °C and 85 °C. Etch rate, etch uniformity and silicon surface roughness were observed.

Abstract: An ultra-compact Bragg grating based on hybrid plasmonics is presented to achieve efficient wavelength selection by a resonate cavity, which is promising for many applications in integrated telecommunications systems.

Abstract: We propose a novel structure to achieve large field enhancement of nanoparticles with silica shell for SERS that nanoparticles are place on a dielectric-load surface plasmonpolariton waveguide supporting guided modes in microfluid detection system.

Abstract: It is important to monitoring the fine particles (PM2.5) in atmosphere as it threatens the public health all over the world. But the existing concentration measuring devices have shortcomings in speed and range. A novel fine particle concentration measuring system based on the ultrasonic attenuation was designed in this paper, which could help to solve the problem. Firstly the mechanism of ultrasonic attenuation in dust cloud was studied to verify the relationship between the concentration and the ultrasonic attenuation. Then the novel concentration measuring system was designed. The micro ultrasonic transducer array was introduced into the system, so the system can be sensitive as well as small. Finally, experiment was conducted to check the performance of this measuring system, and the results show that it could realize measurement quickly.

Abstract: In this investigation, nanoparticles of ferroferric oxide were synthesized and used as the photo initiator in the polymerization of acrylamide. The influences of different factors, including reaction time, light intensity, the content of ferroferric oxide nanoparticles, and the concentration of acrylamide monomer on the synthesis of polyacrylamide were discussed. The possible mechanisms of the photopolymerization irritated by Fe₃O₄ nanoparticles, and the photoinitiation stage with the participantion of the acrylamide radicals were also proposed. The results show that the ferroferric oxide nanoparticles could be successfully applied in the photopolymerization. The optimum conditions of the photopolymerization of acrylamide, which include acrylamide monomer content of 30wt%, reaction time of 30 mins, the Fe₃O₄ nanoparticles concentrations of 1.2 mmol/l, and the light intensity of 8.0 mW/cm².

Abstract: The adsorption of eight drugs (Log P range from-2.64~8.98) was investigated by performing batch adsorption experiments. Experiments were carried out as function of contact time, initial concentration and temperature (25-60°C). The equilibrium adsorption data of drugs on ion-exchange fiber were analyzed by Langmuir and Freundlich models. The results indicate that the Langmuir model provides the best correlation of the experimental data. The results indicate that ion-exchange fiber is suitable as drug carriers for loading drugs.

Abstract: This paper presents a new decoration view functionalization of mesoporous silica to extend their applications to heavy metal ion removal. The study showed that Hacac can be incorporated into the structure through in-situ strategy, and the calcined Hacac-silica possesses advantages of high specific surface area of about 1496 m²/g and pore size of 4nm, ordered spheric morphology of about 300nm in diameter. Auxiliary by ultrasonic technology, the heavy metal ions remove rates are more than 95% for Pb²⁺, Cu²⁺ and Cr³⁺. More choice of chelating agents can be used for further functionalization of silica based mesoporous material.