Effects of thermal annealing temperature and duration on hydrothermally grown ZnO nanorod arrays

In this study, the effects of thermal annealing temperature and duration on ZnO nanorod arrays fabricated by hydrothermal method were investigated. The annealed ZnO/Si(1 1 1) substrate was used for ZnO nanorod array growth. The effects of annealing treatment on the structural and optical properties were investigated by scanning electron microscopy, X-ray diffraction, and room-temperature photoluminescence measurements. With the annealing temperature of 750 °C and the annealing duration of 10 min, both the structural and optical properties of the ZnO nanorod arrays improved significantly, as indicated in the X-ray diffraction and photoluminescence measurement.     

Regioselective allylgallation of terminal alkynes

The reactions of terminal alkynes with allylgallium reagents generated in situ from gallium and allyl bromides gave the corresponding 1,4-dienes in good yield via Markovnikov addition in THF at 70 degrees C.     

Experimental demonstration of 10 Gbit/s transmission with an optical backplane system using optical slots

A practical optical backplane system was prepared with transmitter-receiver processing boards and an optical backplane made from polymeric-waveguide-embedded optical printed-circuit boards. Optical slots were used as connection components between the transmitter-receiver processing boards and the backplane board to permit easy and repeatable insertion and extraction of the boards with micrometer precision. We report 10 Gbit/s data transmission between an optical backplane and the transmitter-receiver processing boards.     

The study on the effect of the substitution of K2CO3 with Ca(OH)2 on kinetics on CO2–lignite coal gasification

Research on Chemical Intermediates - Three kinds of lignite were mixed with K2CO3 and Ca(OH)2 and were gasified with CO2 to investigate the effect that the addition of Ca(OH)2 had on the...     

An Analytical Bond Order Potential for Mg−H Systems

Magnesium-based materials provide some of the highest capacities for solid-state hydrogen storage. However, efforts to improve their performance rely on a comprehensive understanding of thermodynamic and kinetic limitations at various stages of (de)hydrogenation. Part of the complexity arises from the fact that unlike interstitial metal hydrides that retain the same crystal structures of the underlying metals, MgH₂ and other magnesium-based hydrides typically undergo dehydrogenation reactions that are coupled to a structural phase transformation. As a first step towards enabling molecular dynamics studies of thermodynamics, kinetics, and (de)hydrogenation mechanisms of Mg-based solid-state hydrogen storage materials with changing crystal structures, we have developed an analytical bond order potential for Mg−H systems. We demonstrate that our potential accurately reproduces property trends of a variety of elemental and compound configurations with different coordinations, including small clusters and bulk lattices. More importantly, we show that our potential captures the relevant (de)hydrogenation chemical reactions 2H (gas)→H₂ (gas) and 2H (gas)+Mg (hcp)→MgH₂ (rutile) within molecular dynamics simulations. This verifies that our potential correctly prescribes the lowest Gibbs free energies to the equilibrium H₂ and MgH₂ phases as compared to other configurations. It also indicates that our molecular dynamics methods can directly reveal atomic processes of (de)hydrogenation of the Mg−H systems.     

Synthesis of triarylamine‐containing poly(arylene ether)s by nucleophilic aromatic substitution reaction

We report synthesis of a series of new triarylamine‐containing AB‐type monomers and their polymers via nucleophilic aromatic substitution (S_NAr) reaction. Monomers consisting of a hydroxyl group at the para position of the nitrogen group in one phenyl ring and a fluorine leaving group at the para position in another phenyl ring were synthesized via palladium‐catalyzed amination reaction. The fluorine leaving group was activated by trifluoromethyl group at the ortho position and an electron‐withdrawing group (EWG) introduced at the para position of the unsubstituted phenyl ring that enabled control over monomer reactivity. S_NAr reaction of the monomers successfully produced corresponding poly(arylene ether)s with pendant EWGs that exhibited good solubility and thermal stability. Optical and electrochemical properties of the polymers were also affected by incorporation of EWGs. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014 , 52, 2692‐2702     

Antioxidant and binding properties of methanol extracts from indigo plant leaves

This study was conducted to clarify the effect of ultra-pressure treatment on the extraction of bioactive compounds from indigo plant leaves (Polygonum tinctorium Lour.) and on their properties. Leaves were harvested the in mid-August, 2013, from Naju City (Korea), and treated using two methods: ultra-pressure (550 MPa, 3 min) and hot-air (70°C, 24 h). Then, the leaves were ultrasonically extracted with methanol. The content of indirubin in leaves treated with ultra pressure and hot air was (535.55 ± 26.14) mg kg^?1 and (52.63 ± 6.45) mg kg^?1, respectively, and that of tryptanthrin was (165.55 ± 8.74) mg kg^?1 and (153.00 ± 7.62) mg kg^?1, respectively. Polyphenolic content in the leaves extract was (127.24 ± 13.67) mg kg^?1 after the ultrapressure and (88.22 ± 5.33) mg kg^?1 after the hot-air treatment. The content of flavonoids was (2298.67 ± 83.27) mg kg^?1 after the ultra-pressure and (3224.00 ± 21.45) mg kg^?1 after the hotair treatment. Di(phenyl)-(2,4,6-trinitrophenyl)iminoazanium (DPPH) radical scavenging activities of the indigo extract obtained by ultra-pressure and hot-air treatment methods at the concentration of 1 mg mL^?1 were (80.25 ± 0.73) % and (66.54 ± 2.35) %, respectively, and 2,2′-azinobis(3-ethylbenzthiazoline-6-sulphonic acid) (ABTS) radical scavenging activities were estimated as (90.14 ± 0.79) % and (64.45 ± 8.97) %, respectively. The methanol leaf extract after ultra-pressure treatment exhibited higher binding properties to human serum albumin in comparison with catechin and conventional treatments. Consequently, it was assumed that the ultra-pressure treatment is an effective method for the extraction of bioactive compounds from indigo leaves.     

Effects of solvent viscosity on ligand interconversion dynamics in the primary docking site of heme proteins

Interconversion dynamics of the ligand in the primary docking site of myoglobin (Mb) and hemoglobin (Hb) in trehalose and glycerol/D2O mixtures at 283 K was investigated by probing time-resolved vibrational spectra of CO photolyzed from these proteins. The interconversion dynamics in viscous media are similar to those in aqueous solution, indicating that it is minimally coupled to the solvent-coupled large-scale protein motion. Interconversion rates in the heme pocket of Hb in water solution are slower than those of Mb in trehalose glass, suggesting that the interconversion barrier in Hb is intrinsically higher than that in Mb and is not modified by the solvent viscosity.