A disposable single-use electrochemical sensor for the detection of uric acid in human whole blood

We report here a non-enzymatic detecting electrode strip for fast monitoring of uric acid in human whole blood. A single-use amperometric uric acid sensor strip, incorporating a three-electrode configuration, has been fabricated on a polypropylene substrate using low cost screen-printing (thick-film) technology. Both the working and counter electrodes were prepared by screen-printing commercial carbon ink. The integration on the same support of pseudo-reference electrode was obtained by screen-printing a commercial silver ink and subsequent electrochemical pretreatment. Simply by placing a 20 μl human whole blood drop on the strip is enough for uric acid analysis by square-wave voltammetry. Real human whole blood samples were analyzed by this method and compared to the phosphotungstic acid clinical test procedure with satisfactory results.     

Electrochemical chlorination of azulene derivatives: Insight into the mechanism of anodic oxidative chlorination

The cyclic voltammetry behavior of a series of five 1-substituted azulenes has been investigated as well as the electrochemical chlorination of these compounds. In the case of azulene compounds containing electron withdrawing groups which have higher oxidation potentials than that of the chloride ion, the electrochemical chlorination led usually to 3-chloro derivatives. The electrochemical chlorination fails for azulenes with lower oxidation potentials. Additionally some polyhalogenated compounds were obtained by controlled potential electrolyses. The paper also discusses the reaction mechanism of the electrochemical halogenation of 1-substituted azulenes.     

Electrochemical noise analysis for estimation of corrosion rate of carbon steel in bicarbonate solution

We have investigated the electrochemical noise behavior of carbon steel in fully deaerated aqueous bicarbonate solutions, and discussed the optimum conditions of the noise analysis for estimating corrosion rate of the steel. Noise of the potential difference and of the short-circuit current between two identical steel coupons were successfully measured. The time-series noise patterns were transformed into frequency domain by fast Fourier transformation, and then their power spectrum densities (PSDs) at a frequency were determined to be compared with the corrosion rate. The PSDs of the potential and of the current varied with changing environmental factors of bicarbonate concentration, pH, and immersion time. The factors also controlled the corrosion rate of the steel. The PSDs were associated with the corrosion rate, and then it was found that the PSDs of the potential and of the current showed linear correlation with the corrosion rate in log-log scale. There was also linear relationship between the corrosion rate and a spectral noise resistance obtained from the PSDs of the potential and the current. The linearities of the three correlations were better at a lower analyzed frequency. Furthermore, the PSDs of the current and the noise resistance indicated more linear correlation with the corrosion rate than that of the potential. As the simplicity of the measurement system is additionally considered, it is concluded that the PSD of the current noise at an analyzed frequency of 3 mHz is the optimum conditions for estimating the corrosion rate from 10⁻² to 10⁰ A m⁻² in this study.     

高炉喷吹废塑料燃烧动力学研究

为了提供高炉喷吹废塑料新技术工业化应用的理论依据，通过对其动力学参数的求解，研究了高炉喷吹废塑料的燃烧动力学，得出了该燃烧反应是一级反应，且在温度为200℃、塑料配比为20％～25％时活化能最低、燃烧阻力小的结论。     

Automatic processing of psychological distance: Evidence from a Stroop task.

A picture-word version of the Stroop task was used to test the automatic activation of psychological distance by words carrying various senses of psychological distance: temporal (tomorrow, in a year), social (friend, enemy), and hypotheticality (sure, maybe). The pictures implied depth, with the words appearing relatively close to or distant from the observer. The participants classified the spatial distance of words faster when the word's implicit psychological distance matched its spatial distance (e.g., a geographically close word was classified faster when it was "friend" than when it was "enemy"). The findings are consistent with the idea that psychological distance is accessed automatically, even when it is not directly related to people's current goals, and suggest that psychological distance is an important dimension of meaning, common to spatial distance, temporal distance, social distance, and hypotheticality. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Propane conversion over zeolite catalysts: Comments on the role of Ga

The activation of propane using zeolite H-Y and Ga³⁺ exchanged zeolite Y indicates that in the presence of Ga³⁺ the mechanism of propane activation is changed from a cracking pathway to a dehydrogenation pathway. The presence of both Ga³⁺ and H⁺ are required to achieve this effect.     

Electrical and optical properties of MoO3-V2O5 mixed oxide films

Vacuum deposited MoO₃-V₂O₅ films of different molar concentrations have been used for DC electrical conductivity studies at different temperatures. The optical absorption spectra of MoO₃-V₂O₅ films of different molar concentrations have been measured. From these measurements it is found that optical band gap and activation energy vary with molar concentration of MoO₃-V₂O₅ films.     

Electrochemical properties of ultra-long,aligned, carbon nanotube array electrode in organic electrolyte

The electrochemical properties of an electrochemical double-layer capacitor electrode based on an ultra-long (500 μm), aligned, carbon nanotube array (ACNTA) in Et₄NPF₆/propylene carbonate electrolyte are examined. The specific capacitance of the ACNTA electrode in an organic electrolyte is 24.5 F g⁻¹, which is larger than that obtained in an aqueous electrolyte. The results of ac impedance measurements show that the ACNTA electrode gives a high power density and an excellent rate capability in an organic electrolyte. It is shown that the ACNTA electrode has a lower equivalent series resistance and a better rate capability than activated carbon electrode. This is due to the fact that ACNTA possesses a larger pore size and a more a regular pore structure. Both these features are conformed by scanning electron microscopic and nitrogen gas adsorption studies.     

Structural and electrical measurements of CdZnSe composite

TheI—Vcharacterization and the electrical resistivity of selenium rich Se₈₅Cd_15-xZn_x (x = 0, 3, 7, 11 and 15) system at room temperature have been studied. Samples were obtained using melt cooling technique. So prepared samples were then characterized in terms of their crystal structure and lattice parameter using X-ray diffraction method. The materials were found to be poly crystalline in nature, having zinc blend structure over the whole range of zinc concentration. The measurements ofI—V bdcharacteristics have been carried out at different temperatures from room to 140°C. The electrical resistivity of the samples with composition at room temperature has been found to vary between maximum 2.7 x 10⁸ Ωm and minimum 7.3 x 10⁵ Ωm and shows a maximum at 3 at. wt.% of Zn. The carrier activation energy of the samples with composition has also been determined and found to vary from 0.026 eV to 0.111 eV.     

石灰石分解反应的热重动力学研究

用热重分析等研究方法，对我国９个主要产地的石灰石矿样品进行了大量的实验和分析工作，并分别计算出不同产地石灰石的动力学数据。