双[4-(2,4-二特戊基苯氧基)邻苯二腈铜]LB膜材料的合成

近年来,随着LB膜研究的进展,成膜材料的种类逐渐增多、其中有关酞菁衍生物LB膜材料的报道较多。本文合成了下述新型结构的化合物:     

Nickel determination in osteoblast-like cell culture medium by adsorptive cathodic stripping voltammetry with a mercury microelectrode

The purpose of this study is to investigate the influence of nickel, which is an alloying element in commonly used metallic biomaterials, on the biomaterials mineralization process. An electrochemical method was developed to quantify this metal ion in osteoblast-like cell culture medium (OST) by performing adsorptive cathodic stripping voltammetry (CSV) with dimethylglyoxime (DMG) at a mercury film microelectrode (MFM). The optimized analytical conditions and the square-wave CSV parameters for the analysis are: DMG concentration: 5.00 × 10⁻⁴ mol L⁻¹; ammonium chloride buffer: 0.10 mol L⁻¹ (pH 9.2); frequency: 50 Hz, amplitude 20 mV; step: 2 mV; adsorption time: 10 s, deposition potential: −0.70 V and reduction potential: −1.20 V. The limit of detection was 7.70 × 10⁻⁹ mol L⁻¹ for an adsorption time of 10 s. The results achieved by CSV using the MFM were compared to those obtained by atomic absorption spectrometry (AAS) to ensure the reliability of the electrochemical method. The mineralization process was evaluated by biochemical and histochemical assays.     

Morphology,crystal structure,and orientation of poly-p-oxybenzoate on mica

Polymerization of p-acetoxybenzoic acid between mica sheets, from both the melt and dilute solution, in a wide range of polymerization temperatures (180–400°C) yields an epitaxial-like overgrowth of PpOBA on the mica cleavage surface. The PpOBA overgrowth forms long rows by lateral aggregation of ribbon crystals situated in three substrate directions rotated by 60°. The c-axes of the PpOBA phase I and II lattices are parallel to the 001 plane of the mica, coinciding with the a-axes of the mica hexagonal structure. The a_I- and b_II-axes lie predominantly on the mica surface. The surface-orienting effect is tentatively attributed to surface steps and or/polar effects; lattice matching does not occur. The recrystallization of bulk polymer samples previously prepared also leads to ordering between mica like that in melt or solution polymerization. © 1997 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys 35: 1807–1820, 1997     

Improved Electrochemical Performance of Mg-doped ZnO Thin Film as Anode Material for Lithium Ion Batteries

Zn1-xMgxO （x = 0, 0.18） thin films were fabricated on the copper substrates by radiofrequency magnetron sputtering using the high pure argon as a sputtering gas. The Zn1-xMgxO films were characterized by X-ray powder diffraction （XRD）, scanning electron microscope （SEM） and galvanostatic tests. The electrochemical test showed an improved electrochemical performance of Zn0.82EMg0.18O thin film as an anode material for lithium ion batteries.     

Preparation and Photocatalytic Property of Porous TiO_2 Film with Net-like Framework

By the UV-curing method, a porous TiO2 film with net-like framework has been prepared. The characte-rization results of the porous TiO2 film by means of SEM, TEM, XRD, and N2 adsorption-desorption analysis show that the net-like framework of the porous TiO2 film is composed of TiO2 nanoparticles, forming three dimensional porous structure. The porous TiO2 film exhibits higher photocatalytic activity for the degradation of methylene blue(MB) dye compared with the conventional dense TiO2 film.     

纳米TiO_2薄膜的制备及性能表征

采用溶胶-凝胶法制备了以玻璃为基底具有高光催化活性,表面均匀、透明、无裂纹的纳米TiO2薄膜.研究了反应物配比对薄膜表面形貌、透光率和光催化活性的影响,确定了最佳反应物配比.采用扣除背景干扰的方法,利用甲基橙的降解率对TiO2薄膜的光催化性能进行了评价,对其透光率、光催化活性以及物相形貌进行了表征.结果表明,在最佳反应物配比条件下,所制备的TiO2薄膜表面光滑平整,粒径为纳米级且分布均匀,具有80%高透光率和99%高光催化活性.     

阳离子选择性膜修饰Ir/IrOx-pH电极增敏作用研究

采用阳离子选择性透过膜对Ir/IrOx-pH电极表面进行修饰,提高了电极抗阴离子氧化/还原性物质的干扰能力.利用SEM观察离子选择性透过膜的表面孔径分布;通过循环伏安法研究了氧化物电极在Fe(CN)63- 溶液中的电化学行为.实验表明,选择性透过膜对电极的E-pH线性、准确度、响应时间等无影响,显著改善了电极在含氧化/还原性物质中的使用性能.从而提高了电极的抗干扰能力和灵敏度.     

UV degradation of deoxyribonucleic acid

The effects of UV synchrotron radiation on deoxyribonucleic acid (DNA) cast films have been systematically investigated by vacuum ultraviolet and infrared spectrophotometry as a function of irradiation time. Cast DNA films exposed at 140 nm (8.85 eV) for different irradiation times, revealed consistent changes in their VUV spectra which indicate a decrease of thymine groups and an increase of π → π* transition spectral signature associated with the CO group of the open sugar chain. This result was corroborated by a decrease in CO stretching vibration at 1061 cm⁻¹ observed in the infrared spectra. Both these results are consistent with the creation of single strand breaks in the deoxyribose component of DNA molecule and a decrease in the phosphate groups. It was also shown that UV radiation is effective in damaging the thymine groups involved in Hoogsteen base pairing with adenine. The analysis of the infrared data suggests that the usual spectroscopic fingerprints of DNA denaturation are not necessarily a reliable measure of DNA damage.