Micro-Mechanism of Silicon-Based Waveguide Surface Smoothing in Hydrogen Annealing

The micro-mechanism of the silicon-based waveguide surface smoothing is investigated systematically to explore the effects of silicon-hydrogen bonds on high-temperature hydrogen annealing waveguides. The effect of silicon- hydrogen bonds on the surface migration movement of silicon atoms and the waveguide surface topography are revealed. The micro-migration from an upper state to a lower state of silicon atoms is driven by silicon- hydrogen bonding, which is the key to ameliorate the rough surface morphology of the silicon-based waveguide. The process of hydrogen annealing is experimentally validated based on the simulated parameters. The surface roughness declines from 1.523nm to 0.461 nm.

Surface Modification of AB_2 and AB_5 Hydrogen Storage Alloy Electrodes by the Hot-Charging Treatment

The effect of the hot-charging treatment on the performance of AB(2) and AB(5) hydrogen storage alloy electrodes was investigated. The result showed that the treatment can markedly improve the voltage plateau ratio (VPR), the high rate discharge ability (HRDA), the diffusion coefficient of hydrogen DH and the discharge capacity of the AB2 hydrogen storage alloy electrode. The SEM analysis showed that the hot-charging treatment brings about a Ni-rich surface due to the dissolution of Zr oxides. It is also very helpful for the improvement of the kinetic properties of AB2 hydrogen storage alloy electrode because the microcracking of the surface results in fresh surface. This can be the basic modification treatment for NiMH battery used in electric vehicles (EVs) in the future. But for AB(5) type alloys, the treatment has the disadvantage of impairing the comprehensive electrochemical properties, because the surface of the alloy may be corroded during the treatment. The mechanism of the surface modification of the electrode is also proposed.

Theoretical Calculations on Amphoteric Adsorptions of the Hydrogenated C(100)-2×1 Surface

In this work we study the adsorptions of some small molecules or group on the hydrogenated C（100）-2×1 surface using density functional theory method. The calculated results show that the ionization potential （IP） of the hydrogenated C（100）-2×1 surfaces after adsorption has amphoteric characteristics. From the weak basic NH3 molecule with small IP and negative electron affinity （EA）, through the neutral H2O molecule, to the weak acid HF molecule and the OH group with large EA and IP, the IP values of the adsorbed diamond surfaces vary from decrease, through invariability, to slight increase for HF and obvious increase for OH. In all adsorption species, only the OH group makes the hydrogenated C（100）-2×1 surface change to the metal from the semiconductor with a wide-band gap, while the others only introduce impurity states into the electronic structures of the hydrogenated C（100）-2×1 surfaces.

Adsorption of HCN on Ni/Pt(111)Bimetallic Surfaces Investigated with Density Functional Theory Method

We applied periodic density-functional theory to investigate the adsorption of HCN on x Ni@Pt（111） bimetallic surfaces（x = 1~4）. The results have been compared with those obtained on pure Ni（111） and Pt（111） surfaces. For all bimetallic surfaces,HCN is preferentially tilted with the CN bond parallel to the surface,and adsorption energies increase with an increasing number of layer Ni atoms on the surface. The adsorption energies of HCN on all bimetallic surfaces are larger than that on the Pt（111） surface,whereas the adsorption energies of HCN on 3Ni@Pt（111） and 4Ni@Pt（111） are larger than that on the Ni（111） surface,indicating that the introduction of Ni to the Pt catalyst could increase the activity of bimetallic catalyst in the hydrogenation reaction for nitriles. Larger adsorption energy of HCN leads to a longer C–N bond length and a smaller CN vibrational frequency. The analysis of Bader charge and vibrational frequencies showed obvious weakening of the adsorbed C–N bond and an indication of sp2 hybridization of both carbon and nitrogen atoms.

Experimental Design Technique on Removal of Hydrogen Sulfide using CaO-eggshells Dispersed onto Palm Kernel Shell Activated Carbon：Experiment,Optimization,Equilibrium and Kinetic Studies

This study presents the use of chicken eggshells waste utilizing palm kernel shell based activated carbon（PKSAC） through the modification of their surface to enhance the adsorption capacity of H2S. Response surface methodology technique was used to optimize the process conditions and they were found to be： 500 mg/L for H2S initial concentration, 540 min for contact time and 1 g for adsorbent mass. The impacts of three arrangement factors（calcination temperature of impregnated activated carbon（IAC）, the calcium solution concentration and contact time of calcination） on the H2S removal efficiency and impregnated AC yield were investigated. Both responses IAC yield（IACY, %） and removal efficiency（RE, %） were maximized to optimize the IAC preparation conditions. The optimum preparation conditions for IACY and RE were found as follows： calcination temperature of IAC of 880 ℃, calcium solution concentration of 49.3% and calcination contact time of 57.6 min, which resulted in 35.8% of IACY and 98.2% RE. In addition, the equilibrium and kinetics of the process were investigated. The adsorbent was characterized using TGA, XRD, FTIR, SEM/EDX, and BET. The maximum monolayer adsorption capacity was found to be 543.47 mg/g. The results recommended that the composite of PKSAC and Ca O could be a useful material for H2S containing wastewater treatment.