Thin‐film Potentiometric Sensor to Detect CO2 Concentrations Ranging Between 2 % and 100 %

A potentiometric thin‐film sensor to detect CO₂ in a wide range (2–100 %) has been developed. The system has been fabricated depositing a reference electrode of Pt, a solid electrolyte of YSZ (Yttria‐stabilized Zirconia), a sensing phase made of Li₂CO₃ and a working electrode of Au via Physical Vapor Deposition (PVD). Characterization of the different elements has provided the optimal fabrication parameters and the system response for CO₂ concentrations can be measured from 2 to 100 % at 450 °C. The sensor behaves as a non‐Nerstian system and slightly deviates from a linear response with the logarithm of CO₂ until the CO₂ concentration reaches the 30 %. Higher CO₂ amounts make the response divert more from the Nernst law but give a stable and reproducible response to CO₂ in a wide range of concentrations. Based on these promising results the recovery time, stability, repeatability and selectivity of the sensor have been measured. The performance showed by the thin film sensor proves the feasibility of the use of this system for biogas and natural gas applications owing to its very good consistency at low temperature in a wide concentration range.     

Nanostructured catalysts for cathodes of oxygen-hydrogen fuel cells

Bimetallic catalysts platinum-cobalt, platinum-chromium, and platinum-tungsten, deposited onto highly dispersed carbon black from complex cluster-type compounds of corresponding metals with a 1: 1 atomic ratio of metals are developed. The catalysts are characterized by methods of x-ray diffraction analysis and energy dispersive analysis of x-rays. The procedure involving use of a thin-film rotating disk electrode is employed to probe kinetic parameters of the oxygen reduction reaction on the catalysts developed. The investigated binary catalysts exhibit specific electrochemical characteristics that are not inferior and, in some cases, are superior to the characteristics intrinsic to the commercial platinum catalyst E-TEK, when tested in the composition of a gas-diffusion electrode under conditions that are close to real conditions in which cathodes of oxygen-hydrogen fuel cells operate.     

制备透射电镜用表面膜薄膜样品的新方法

本文提出了一种用机械研磨和离子减薄技术制备透射电镜用薄膜样品的新方法,并且成功地将其应用于磨损表面氧化膜的结构分析,指出在铸铁油润滑磨损过程中于氧化磨损状态下磨损表面氧化膜系由Fe_3O_4均相所组成。     

Active Optical Poly(vinylchloride) Thin-Film Waveguide Ion Sensor

The effectiveness of a proposed PVC (Poly(vinylchloride)) thin-film waveguide ion sensor with high sensitivity which is based on a polymer matrix to measure the concentration of various biochemical ions is assessed. The waveguide is made of PVC co-polymer matrix containing ionophore, dioctylphthalate and chromoionophore, and plays important roles both in light propagation and in selective ion sensing. To evaluate the efficiency of the sensor, standard calcium solution is applied. Results showed the proposed sensor to be very effective as an ion sensor. This active waveguide sensor has the advantages of utilizing both the molecular recognition technique and the waveguide detection technique.     

Advanced solar materials for thin-film photovoltaic cells

As one of the most promising solutions for the green energy, thin-film photovoltaic cell technology is still immature and far from large-scale industrialization. The major issue is getting low cost and stable module efficiency. To solve these problems, a large amount of advanced solar materials have been developed to improve all parts of solar cell modules. Here, some new solar material developments applied in different critical parts of chalcogenide thin-film photovoltaic cells are reviewed. The main efforts are focused on improving light trapping and antireflection, internal quantum efficiency and collection of photo-generated carriers.     

Self-dual Vortices in Schroedinger-Chern-Simons Model

By making use of the U（1） gauge potential decomposition theory and the Ф-mapping topological current theory, we investigate the Schroedinger-Chern-Simons model in the thin-film superconductor system and obtain an exact Bogomolny self-dual equation with a topological term. It is revealed that there exist self-dual vortices in the system. We study the inner topological structure of the self-dual vortices and show that their topological charges are topologically quantized and labeled by Hopf indices and Brouwer degrees. Furthermore, the vortices are found generating or annihilating at the limit points and encountering, splitting or merging at the bifurcation points of the vector field Ф.     

Application of X-ray fluorescence holography to the analysis of the interior and surface of an yttrium oxide thin film

We report on the characterization of a thin film of yttrium oxide by X-ray fluorescence holography. The sample has a layered structure with an YO base layer and an oxidized Y₂O₃ surface. Both layers are clearly observed in the atomic image reconstructions, and their local structure is analyzed. We show that by using incident energies close to the absorption edge of the fluorescing atom, it becomes possible to observe the thin surface layer clearly, even next to a base layer containing the same fluorescing element.