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61.
Photoelectrocatalytic oxidation of o-phenols on copper-plated screen-printed electrodes 总被引:1,自引:0,他引:1
A novel and sensitive detection method based on photoelectrocatalytic oxidation of o-diphenols was demonstrated on a copper-plated screen-printed carbon electrode (designated CuSPE) in pH 8 phosphate buffer solution. The o-diphenols can be detected amperometrically through electrochemical oxidation at a low applied potential of -0.1 V versus Ag/AgCl, where the CuSPE is much less subject to interfering reactions. The mechanism that induces good selectivity of the CuSPE is explained in terms of the formation of a cyclic five-member complex intermediate (Cu(II)-o-quinolate). A prototype homemade flow through cell design is described for incorporating the photoelectrode and light source. Electrode irradiation results in a large increase in anodic current. The oxidative photocurrents produced by irradiation increase with light intensity presumably because of the formation of semiconductor Cu(2)O. The principle used in this study has an opportunity to extend into various research applications. 相似文献
62.
A. C. Siegel D. A. Bruzewicz D. B. Weibel G. M. Whitesides 《Advanced materials (Deerfield Beach, Fla.)》2007,19(5)
Flexible metallic wires embedded in poly(dimethylsiloxane) are produced with microscale dimensions by injecting heated, liquid solder into microfluidic channels and cooling, as reported by George Whitesides and co‐workers on p. 727. This approach is used to fabricate complex, metallic microstructures that are twisted (as shown), rolled, or woven into fabrics. The structures can be rigid or flexible, depending on the type of solder used, and breaks in the metal can be “healed” by reheating the device. This method of fabrication may find applications in flexible electronic circuits, 3D metallic microstructures, and hybrid electronic–microfluidic devices. 相似文献
63.
This paper studies leadership dynamics in the development of a knowledge sharing system. We apply the concept of distributed leadership, examining how leadership roles are distributed across different individuals in the organisation during developing and implementing a knowledge sharing system. The results of a case study demonstrate that the leadership was fulfilled by the interdependent and emergent roles played by several individuals: the spearheading and coordinating roles of a knowledgeable and persistent project leader, the supporting and steering roles carried by a group of perceptive and collaboration-inclined executives, and the knowledge sharing and momentum driving roles performed by knowledge champions. Each of these leadership influences was indispensable. None of the leaders could have accomplished this task individually, without the active involvement of the other types of leaders. This research makes its contribution to the understanding of the emergence and dynamics of distributed leadership in the information system environment, and demonstrates the importance of a full awareness of distributed leadership as tasks are carried out in developing a knowledge sharing system. 相似文献
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AbstractThe dynamic deformation characteristics and failure behaviour of laminated carbon fibre reinforced Al–Li metal matrix composite has been studied experimentally with the objective of investigating the dependence of mechanical properties on the applied strain rate and fibre volume fraction. A vacuum melting/casting process was used for manufacturing the tested composite. Impact testing was performed using a Saginomiya 100 metal forming machine and a compressive split Hopkinson bar over a strain rate range of 10-1 s-1 to 3×103 s-1. It is shown that the flow stress of the composite increases with strain rate and fibre volume fraction. The highest elongation to fracture values were found at low rate loading conditions, although a significant increase in ductility is obtained in the dynamic range. The composite appears to exhibit a lower rate of work hardening during dynamic deformation. Strain rate sensitivity and activation volume are strongly dependent on strain rate and fibre volume fraction. Fractographic analysis using scanning electron microscopy reveals that there is a distinct difference in the morphologies of the fractures, with corresponding different damage mechanisms, between specimens tested at low and high strain rates. Both strain rate and fibre volume fraction are important in controlling fibre fragment length and the density of the Al–Li debris. The relationships between mechanical response and fracture characteristics are also discussed. 相似文献
68.
Pula G Perera S Prokopi M Sidibe A Boulanger CM Mayr M 《Proteomics. Clinical applications》2008,2(6):882-891
The release of proteins and membrane vesicles in the bloodstream regulates diverse vascular processes, both physiological, such as angiogenesis and haemostasis, and pathological, such as atherosclerosis and atherothrombosis. Proteomics, beside its canonical application for the expression profiling in cells and organs, can be applied to the study of secreted proteins and microvesicles, which play a significant role in the homeostasis of the vasculature, and the development of the atherosclerotic disease. 相似文献
69.
Sue‐Siang Teh Rajeev Bhat Rosma Ahmad Wan‐Nadiah Wan‐Abdullah Min‐Tze Liong 《International Journal of Food Science & Technology》2010,45(10):2089-2095
We aimed at evaluating agricultural wastes as solid supports for the immobilisation of lactobacilli in a liquid media, namely soymilk. Lactobacillus acidophilus FTDC 1331, L. acidophilus FTDC 2631, L. acidophilus FTDC 2333, L. acidophilus FTDC 1733 and L. bulgaricus FTCC 0411 were immobilised on solid supports produced from durian (Durio zibethinus), cempedak (Artocarpus champeden) and mangosteen (Garcinia mangostana). The immobilised cells were inoculated into soymilk and stored at 4 °C over 168 h. Soymilk inoculated with non‐immobilised cells was used as the control. Immobilised cells showed higher survivability over 168 h compared to the control, accompanied by higher reduction of simple sugars and oligosaccharides in soymilk. Higher growth and higher utilisation of substrates also led to the higher production of lactic and acetic acids, which lowered the pH in soymilk compared to the control. Our results illustrated that agrowastes could be used as immobilisers to enhance the growth of lactobacilli in a liquid medium. 相似文献
70.
Glass doped TiO2 (GTO) thin films were deposited by radio frequency (RF) magnetron sputter at room temperature and annealed in a reductive atmosphere containing 90 % N2 and 10 % H2. Highly dense TiO2 ceramic mixed with glass consisting of multi-metal oxides (as a sintering aid) was used as the sputtering target. This sintering aid allows low temperature densification of TiO2 target through a liquid phase wetting mechanism, and also works as a doping resource. XRD and FESEM were carried out to characterize the microstructure of the GTO films and the results reveal that the doping of multi-metal ions enhances the crystallization and increases the grain size of TiO2 films. TEM analysis also showed that these metal ions were dissolved into TiO2 lattices. The electrical and optical properties of TiO2 thin films at different glass concentrations were evaluated and compared to the films merely doped with MoO3. The electrical resistivity of the GTO films reaches 9.1 × 10–4 Ω·cm at 2 wt% glass doping, corresponding to a carrier density of 8.9 x 1020 cm-3 and a mobility of 7.1 cm2/Vs. Meanwhile, the electrical resistivity of the TiO2 film doped with glass was found to be lower than that of MoO3-doped film. This was mainly attributed to the increase in carrier concentration by double doping effect of glass. The optical band gap of the GTO films ranged from 3.34 to 3.42 eV, which is greater than that of the un-doped TiO2 film. This blue shift of approximately 0.18 eV was due to the Burstein-Moss effect. 相似文献