Advanced Materials Research Vols. 616-618

Abstract: Al wire bonding lift-off is one of the main failure modes of IGBT module. When the severity of the failure mode is different, the temperature character of IGBT is also different. This paper presents a methodology based on 3D electro-thermal coupling finite elements modeling intended to analyze the relation between the failure degree and the temperature, and compares the influence degree of Al wire bonding lift-off to the performance of IGBT module. This method and the corresponding results help to evaluate Al wire bonding lift-off how they influence the performance of IGBT, determine the failure, establish the failure standards and find the optimization of structure design.

Abstract: Regioregular head-tail poly(3-hexylthiophenes) (HT-P3HT) with a controlled high molecular weight and a small polydispersity have been synthesized via an improved Kumada catalyst-transfer polycondensation (KCTP) by using the new-prepared hexylmagnesium bromide as the Grignard reagent. As the amount of nickel catalyst dichloro[1,3-diphenylphosphinopropane] nickel (Ni(dppp)Cl2) was 0.5% mol of the amount of monomer 2,5-dibromo-3-hexylthiophene (DBHT) we can obtain a HT-P3HT with a high molecular weight Mn (38 449) and a small polydspersity (1.18). By using of LiCl as a co-catalyst, the regioregularity of the P3HT with high molecular weight (40 270) is maintained and the PDI (1.03) is smaller than that of the P3HT polymerized in the absence of LiCl but the conversion ratio of the monomer is promoted. The HT-P3HT with high molecular weight and small polydispersity will be an attractive candidate applied in solar cells.

Abstract: Consider the floor slab reinforced by the increases of the bending capacity of the negative moment on the beam end, the derivation of the nodes under the floor and beam together calculation of bearing capacity formula. Calculate and compare ordinary floor and the floor to the bottom of the beam end and end-column section bearing capacity open-angle seam. The results show that the slit in the floor open-angle measures, due to the reinforcement in the slab near the beam end is cut off, the beam end flexural capacity reduced by 19%, the column end bearing capacity is very small, the bearing capacity of the beams side of the gap increases, the does not affect the bearing capacity of the premise to ensure strong column and weak beam seismic requirements.

Abstract: Nanosize oxides with acidic or basic sites could neutralize the droplets of chemical warfare agents. Refined bleaching powder was added to increase the reactivity of the nanosize oxides for degradation of GD(3,3-dimethyl-2-butyl methylphophonofluoridate or Soman) and VX(O-ehtyl S-2-(diisopropylamino)ethyl methyl-phosphonothioate). It was found that all the studied decontaminant powders exhibited room-temperature reactivity for GD and VX droplets which depends on their surface acid–base property. Decontaminant powders with basicity like nanosize MgO have the best activity towards GD and the degradation rate was improved obviously for N-MgO due to the adding of refined bleaching powder. However, surface acidity was very important for neutralizing VX over the decontaminant powders.

Abstract: The saturate granular activated carbon(GAC) which adsorbed Ni²⁺ is regenerated using dual-frequency ultrasound. The individual frequency is 45KHz, 80KHz and 100KHz respectively. The experimental results show that the regeneration efficiency using dual-frequency ultrasound is better than that using single- frequency ultrasound under the same experimental condition. When the two ultrasound’s frequency is 45KHz, the regeneration efficiency is 81.03%, comparing single- frequency ultrasound it increase by 40% and it is the best in six group dual-frequency ultrasound. In conclusion, the dual-frequency ultrasound regeneration showed a possibility as an alternative to chemical and thermal regeneration of GAC.

Abstract: Direct and rapid heating by microwave irradiation in combination with sealed vessel processing in many cases enables reactions to be carried out in a fraction of the time generally required using conventional conditions. This makes microwave chemistry an ideal tool for rapid reaction scouting and optimization of conditions, allowing very rapid progress through hypotheses-experiment-results iterations. Many scientists both in academia and industry have turned to microwave synthesis as a front-line methodology for their projects.

Abstract: This document explains and demonstrates the problem of Methanol and propylene oxide propoxylation, ZrO₂ load active alkali metal oxides MgO the catalytic propoxylation method, analyzed a new type of catalyst activity and selectivity. The results show that the synthesis of MZ complex oxide as a catalyst for the reaction of Methanol substrate, through the catalytic reaction of propylene oxide, selective access to the propylene glycol ether, High selectivity synthesis 1-Methoxy-2-propanol. Synthesis of complex oxide catalyst MZ series in the course of the performance of the primary ether good selectivity, Primary ether, second ether ratio greater than 12, and the catalytic activity is also high (about 91% of all).

Abstract: The mechanical property of Zr52.5Cu17.9Ni14.6Al10Ti5 bulk metallic glass was investigated at different strain-rate range. It is indicated that the yield strength of the Zr52.5Cu17.9Ni14.6Al10Ti5 bulk metallic glass is insensitive to quasi-static strain rates ranging from 4×10-4 s-1 to 4×10-3 s-1. However, plasticity remarkably decreases with increasing strain rate under compression tests. The more shear bands were observed on the side surface of the fractured samples by SEM at low strain rate, which is contributed to the improved ductility.

Abstract: This paper studied the different formation mechanism and the corrosion protection mechanism of oxide skin in the conditions of WOT and OT in the supercritical units. The WOT tube and OT tube of the high temperature superheater were detected by visual macro inspection, their microscopic structures were analyzed by electron microscopy and their elemental compositions were detected by EDS. The authors put forward steam oxidation mechanism of WOT and peroxide-chromium evaporation mechanism of OT. The test results were analyzed by chemical thermodynamics and chemical kinetics. The experiment and analysis proved that: the oxide skin of WOT’s tube retained the alloying elements and the design of protective structures, but the oxide skin of OT’s tube lost the alloying elements and it had not good protective properties. The studies had shown that: in compared of the WOT and OT, the WOT had a good corrosion protection and a significant advantage of preventing abnormal rapid growth of oxide skin, so WOT was the best choice for feed-water treatment.

Abstract: Aiming at the glass-to-metal seals serving in the Solar Thermal Power (STP), glass-to-metal vacuum brazed joints were studied. Scanning electron microscopy (SEM) and X-ray diffraction (XRD) analysis were performed to examine the microstructure and element contents of interface seam on the glass-to-metal vacuum brazed joints. Also, the compositional concentration of the interface seam was measured by using energy dispersive spectroscopy (EDS).