Deposition of Hydrogen-Free Silicon Nitride Thin Films by Microwave ECR plasma Enhanced Magnetron Sputtering at Room Temperature

Hydrogen-free silicon nitride （SiNx） films were deposited at room temperature by microwave electron cyclotron resonance （MW-ECR） plasma enhanced unbalance magnetron sputtering system. Both Fourier-transform infrared spectroscopy and x-ray photoelectron spectroscopy are used to study the bonding type and the change of bonding structures of the silicon nitride films. The results indicate that the chemical structure and composition of SiNx films deposited by this technique depend strongly on the N2 flow rates, the stoichiometric SiNx film, which has the highest hardness of 22.9 GPa, could be obtained at lower N2 flow rate of 4 sccm.     

不同加载方式下路堤沉降性状与预测模型研究

从考虑土体流变的本构关系出发 ,证明了瞬时加载、线性或者近似线性加载和分级加载情况下路堤沉降的性状 ,提出了从数学上能满足各自变形特征的预测模型 ,工程实例分析表明了在不同条件下采用不同模型的合理性和实用性     

Preparation of well-aligned carbon nanotubes by pyrolysis of phenolic resin in anodic alumina pores

Well-aligned carbon nanotubes (CNTs) of high quality were synthesized by pyrolysis of phenolic resin at 800 °C in anodic alumina oxide (AAO) pores under argon protection. The innocuous source materials and safe operational conditions permit this method to synthesize well-aligned CNTs in large-scale and low cost. The formation mechanism of the synthesized CNTs is also proposed in this work by a series of visual sketches and is proved with obvious evidence. Firstly, phenolic resin nanotubes form in the template pores through the evaporation of solvent. Heat treatment then transfers these tubes into CNTs.     

Étude sur les familles normales et les familles quasi-normales de fonctions méromorphes

Rendiconti del Circolo Matematico di Palermo Series 1 -     

Crystallization of Arthrobacter sp. strain 1C N-(1-D-carboxyethyl)-L-norvaline dehydrogenase and its complex with NAD+

The novel NAD+-linked opine dehydrogenase from a soil isolate Arthrobacter sp. strain 1C belongs to an enzyme superfamily whose members exhibit quite diverse substrate specificites. Crystals of this opine dehydrogenase, obtained in the presence or absence of co-factor and substrates, have been shown to diffract to beyond 1.8 ? resolution. X-ray precession photographs have established that the crystals belong to space group P21212, with cell parameters a = 104.9, b = 80.0, c = 45.5 ? and a single subunit in the asymmetric unit. The elucidation of the three-dimensional structure of this enzyme will provide a structural framework for this novel class of dehydrogenases to enable a comparison to be made with other enzyme families and also as the basis for mutagenesis experiments directed towards the production of natural and synthetic opine-type compounds containing two chiral centres.     

The role of cavity sites in surface-enhanced Raman scattering

Thermal desorption spectra (TDS) of pyridine from silver films deposited in ultra high vacuum are reported. Marked differences in the TDS are seen depending on the deposition conditions and the thermal history of the films, which have been correlated with surface-enhanced Raman scattering (SERS). These results as well as some of the observations in electrochemical systems are discussed in light of the recent Xe probe analysis carried out by Albano et al.     

Hydrothermal synthesis and structure characterization of a new 3D vanadium hydrogen phosphite with 14-ring channels: (C5N2H14)[VO(H2O)]3(HPO3)4·H2O

A new 3D vanadium hydrogen phosphite, (C₅N₂H₁₄)[VO(H₂O)]₃(HPO₃)₄·H₂O, has been prepared by hydrothermal reactions and characterized by single crystal X-ray diffraction, infrared spectroscopy, thermogravimetric analysis, and magnetic techniques. It crystallizes in the triclinic space group P-1 (no. 2) with , , , α=76.124(3)°, β=83.726(4)^o, γ=75.222(4)^o, Z=2. The structure is built up from sharing equatorial oxygen atoms of VO₅(H₂O) octahedra with HPO₃ tetrahedra, which can be viewed as a (3,4) connected net. The framework is mainly constructed by two types of four-ring related chains. Intrachain and interchain hydrogen bonds play an important role on supporting the framework structure. The 14-ring tunnels in the structure are filled with 1-methypiperazinium and water molecules, which also contribute the hydrogen bonding with the vanadium phosphite framework.     

New benzo[b]furans as electroluminescent materials for emitting blue light

[structure: see text] New functionalized mono- and bis-benzo[b]furan derivatives were synthesized and developed as blue-light emitting materials. They possessed a CN, CHO, CH=CHPh, CH=CPh(2), or CH=CHCOOH group at the C4-position. Two benzo[b]furan nuclei in bis-benzo[b]furan derivatives were connected by a divinylbenzene bridge. With good volatility and thermal stability, bis-benzo[b]furan 7a was fabricated as a device. It emitted blue light with brightness 53430 cd/m(2) (at 15.5 V) and high maximum external quantum efficiency 3.75% (at 11 V).     

Propane fuel cells using phosphoric-acid-doped polybenzimidazole membranes

Propane fuel cells using H(3)PO(4)-doped polybenzimidazole polymer membranes produce low and unsustainable current densities at temperatures up to 250 degrees C under anhydrous conditions. Stable intermediate species blocked the surface of noble metal anode catalysts, and the intermediate species could not react further into desorbable final products. In contrast, when water was introduced by light humidification (S(r) 0.08%) of the propane stream, sustainable and higher current densities were achieved. Water participated in the reaction sequence to form surface-bound hydrocarbon and then oxygen-containing intermediates and thereby generated CO and CO(2) as the only carbon-containing products.