Facile preparation of SnC2O4 nanowires for anode materials of a Li ion battery

A simple method of creating densely-packed nanostructures of functional metal oxides is attractive, but it has always been a challenge. Here, we synthesize well-distributed nanostructures of Sn complexes (SnC₂O₄ and SnO₂) via a simple chemical anodization technique followed by annealing. Chemical anodization of Sn surface in oxalic acid, using various organic solvents, provides one-dimensional nanostructures of SnC₂O₄. Length and packing density were precisely controlled by several parameters: solubility of oxalic acid, dielectric constant of organic solvents, and the ion transfer of proton and oxalate anion. Further thermal decomposition converts the SnC₂O₄ nanowires into SnO₂ nanowires, maintaining the nanostructure form in the process. In addition, we expect that the mixture of SnC₂O₄ and SnO₂ nanowires synthesized by this approach might be potential alternative anode materials for prompt charging and discharging Li ion batteries.     

A comparative study on the morphological features of highly ordered titania nanotube arrays prepared via galvanostatic and potentiostatic modes

The formation of highly ordered, vertically aligned titania (TiO₂) nanotubes (NTs) via the cost effective galvanostatic and potentiostatic anodization techniques is reported. In both the approaches, the variation of water content in terms of fresh and used ethylene glycol based electrolyte has been considered as a significant parameter to genuinely investigate each of the anodization modes. Noteworthy differences and influences were clearly observed in terms of anodization kinetics and the resulting tubular morphology, such as architecture and arrangement during the development TiO₂ NTs arrays. The as-synthesized samples were characterized by powder X-ray diffraction (XRD), Field emission scanning electron microscope (FESEM) and Energy dispersive X-ray analysis (EDX).     

ZnO-SnO2透明导电薄膜的制备及性能研究

采用二步成胶工艺制备ZnO-SnO₂透明导电薄膜,应用X射线衍射、原子力显微镜、紫外-可见分光光度计、薄膜分析仪及四探针仪等对薄膜的结构、表面微观形貌、透过率和导电性能进行表征.结果表明,锌锡摩尔比为9/12,退火温度为500 ℃时,薄膜的透过率达90%,电阻率为3.15×10-3 Ω·cm.与其它工艺相比,二步成胶工艺所制备出的ZnO-SnO₂透明导电薄膜性能优异.     

Surface modification of titanium by anodic oxidation in phosphoric acid at low potentials. Part 2. In vitro and in vivo study

Electrochemical studies in SBF solution were performed, in order to determine the best corrosion resistance condition, comparing as‐received titanium, covered with its native surface oxide, and titanium anodized in phosphoric acid. The results indicate that the anodic films obtained at a constant potential of 30 V have higher barrier effect, and the protective layer remains effective against the aggressive anions present in SBF after 30 days of immersion. Due to the promising corrosion performance in simulated biological media coupled with the biocompatible surface characteristics, anodic films on titanium obtained at 30 V were implanted on Wistar Rats to compare the osseointegration results of this modified surface with that corresponding to as‐received titanium. It was found that, after 8 weeks of implantation, although the amount of bone surrounding the implant did not differ across the two different surface implants conditions, bone formation at the implant interface was found to be more homogeneous in anodized titanium. Copyright © 2013 John Wiley & Sons, Ltd.     

Initial attachment and spreading of MG63 cells on nanopatterned titanium surfaces via through-mask anodization

It is well established that nanosized surface topography significantly affects cell response at a biomaterial surface. Here we used a through-mask anodization technique to fabricate well-defined titania nanopillars with tunable feature sizes from 15 to 100 nm on bulk titanium (Ti) substrates and studied their effects on initial attachment and spreading of osteoblast-like cells (MG63). An increase of titania pillar height from 15 to 100 nm resulted in reduced spreading of MG63 osteoblast-like cells and the higher pillar structures also gave rise to heavily elongated cells. By using a FIB/SEM dual beam microscope the interface between MG63 cells and nanopatterned Ti surfaces could be studied in more detail. It was found that the higher pillar structures prevented the cells to conform to the surface topography leaving voids in between the cells and the substrates. The results found in this study agree with previous studies that cells response better to surfaces with smaller (<20 nm) features.     

手性碳量子点的制备及其应用

手性碳量子点(CQDs)因兼具优异的荧光性质、良好的生物相容性、较低的毒性、易于功能化以及手性特征等,在催化、检测和生物医学等领域具有广阔的应用潜力。目前,通过一步法或两步法制备的手性CQDs,已应用于手性催化、手性检测、高尔基体靶向成像、选择性调控酶和蛋白活性、选择性调控细胞能量代谢和促进植物生长等领域。然而,手性CQDs的发展初露头角,需进一步完善可控合成工艺,制备高荧光量子产率的长波长手性CQDs,使其在生物医学等领域绽放异彩。     

Hierarchically Porous Nickel Oxide Nanosheets Grown on Nickel Foam Prepared by One‐Step In Situ Anodization for High‐Performance Supercapacitors

Porous NiO nanosheets are successfully grown on nickel foam substrate through an in situ anodization by using molten KOH as the electrolyte. High‐purity NiO is directly obtained by this one‐step method without any subsequent treatment. The obtained NiO supported on nickel foam is used as a binder‐free electrode for a supercapacitor and its pseudocapacitive behavior has been investigated by cyclic voltammetry and galvanostatic charge–discharge tests in a 6 M aqueous solution of KOH. Electrochemical data demonstrates that this binder‐free electrode possesses ultrahigh capacitance (4.74 F cm^?2 at 4 mA cm^?2), excellent rate capability, and cycling stability. After 1000 cycles, the areal capacitance value is 9.4 % lower than the initial value and maintains 85.4 % of the maximum capacitance value.     

不等频两步激发Li蒸汽产生红外受激辐射特性研究

本文首次报道了利用不等频两步激发Li蒸汽,获得了五条红外受激辐射和串级辐射.并对受激辐射特性进行了研究.     

Computer-assisted optimization of mobile phase compositions and development distance selectivity in gradient two-step development high-performance thin-layer chromatography

A computer-assisted method is presented for optimization of mobile phase compositions and development distance in gradient two-step development HPTLC. The method is based on a system which can predict the final Rf values for gradient two-step development from values measured using five preliminary runs. The statistical scanning method is then used for optimization, using Rf difference as the selection criterion. The method was evaluated using a mixture of eight components. Excellent agreement was obtained between predicted and experimental results. Gradient two-step development HPTLC, mobile phase composition optimization, velopment distance optimizationde-