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921.
Conformal anodic oxidation of aluminum thin films 总被引:1,自引:0,他引:1
Cojocaru CS Padovani JM Wade T Mandoli C Jaskierowicz G Wegrowe JE Fontcuberta i Morral A Pribat D 《Nano letters》2005,5(4):675-680
Membrane-based synthesis, also called template synthesis, is a very general approach used to prepare arrays of nanomaterials with monodispersed geometrical features. The most commonly used porous templates are track-etched polycarbonate and porous anodic alumina membranes. Common to all these templates is the fact that the pores are perpendicular to the surface of the membrane. Here, a novel approach is presented, where the pores are synthesized parallel to the surface of the membrane. For the first time, the anodic oxidation of an aluminum thin film is performed laterally, i.e., parallel to the surface of the substrate, instead of perpendicular as usually done. For low anodic oxidation voltages (between 3 and 5 V) we obtain highly regular and ordered pore arrays, at least over a few hundred nanometers length, with a minimum pore size of approximately 3 to 4 nm. With such porous alumina structures, the controlled in-plane organization of arrays of template-grown nanowires and carbon nanotubes for reproducible device fabrication should be much easier. 相似文献
922.
Pérez B Pumera M del Valle M Merkoçi A Alegret S 《Journal of nanoscience and nanotechnology》2005,5(10):1694-1698
A novel glucose biosensor based on a rigid and renewable carbon nanotube (CNT) based biocomposite is reported. The biosensor was based on the immobilization of glucose oxidase (GOx) within the CNT epoxy-composite matrix prepared by dispersion of multi-wall CNT inside the epoxy resin. The use of CNT, as the conductive part of the composite, ensures better incorporation of enzyme into the epoxy matrix and faster electron transfer rates between the enzyme and the transducer. Experimental results show that the CNT epoxy composite biosensor (GOx-CNTEC) offers an excellent sensitivity, reliable calibration profile, and stable electrochemical properties together with significantly lower detection potential (+0.55 V) than GOx-graphite epoxy composites (+0.90 V; difference deltaE = 0.35 V). The results obtained favorably compare to those of a glucose biosensor based on a graphite epoxy composite (GOx-GEC). 相似文献
923.
Prediction of the chemical equilibrium constant for peracetic acid formation by hydrogen peroxide 总被引:1,自引:0,他引:1
Milovan?Jankovi? Sne?ana?Sinadinovi?-Fi?erEmail author 《Journal of the American Oil Chemists' Society》2005,82(4):301-303
An expression for temperature dependence of the chemical equilibrium constant for peracetic acid synthesis from acetic acid
and hydrogen peroxide in an aqueous solution, derived on the basis of the van't Hoff and Kirchhoff equations, was proposed.
The reverse trend of the chemical equilibrium constant vs. temperature was apparent when the predicted values of the constant
were compared with experimental ones taken from the literature. However, using the proposed model to calculate the chemical
equilibrium constant resulted in better prediction of the equilibrium composition for peracetic acid synthesis at 297.5 K
than using experimental data from the literature. 相似文献
924.
925.
This study investigated the relationship between arsenic concentrations in drinking water in four towns/villages in eastern Croatia and corresponding hair arsenic concentrations of residents. The mean arsenic concentrations in community drinking water samples were 0.14, 37.88, 171.60, and 611.89 microg/l. The corresponding mean concentrations of the element in hair samples of subjects residing in each of the localities were 0.07 (n=11), 0.26 (n=17), 1.74 (n=11), and 4.31 microg/g (n=23). Chronic exposures to arsenic levels estimated in three investigated locations could present a serious health threat to around 3% of Croatian population. 相似文献
926.
Transparent exopolymer particles (TEP) are generated during transformation processes within the non-living organic matter continuum in the seawater. Seasonal dynamics of TEP along the Po River Delta-Rovinj transect was followed during the 3-year period, using a spectrophotometric method of determination of TEP. Relationships between TEP and phytoplankton biomass (chlorophyll a), abundance and composition, as well as phaeophytin, were analysed. Microphytoplankton spring blooms are confirmed to be an important source of TEP, with some species more related to TEP concentration dynamics, such as Chaetoceros sp. and Skeletonema costatum. Notable spatial west to east gradient of autotrophic biomass and consequently of TEP was observed, as well as gradual decrease with depth. In addition, TEP concentration increments were observed up to 2 months before the mucilage events followed by the decrease of TEP concentration during the event itself. Pattern of TEP dynamics in the years with mucilage events was the most pronounced in 2002, when the event was spatially and temporally the most extended. 相似文献
927.
The influence of the uncompensated time delay incurred in the nonoptimum symbol decision filter on the error performance of a decision-directed c.p.s.k. demodulator is considered. An iterative method for the probability of bit error computation is used. 相似文献
928.
Sevdalina P. Valčeva 《Fuel》1979,58(1):55-58
Reflectance of macerals from Palaeogene brown coal from the Pernik basin in Bulgaria was determined using an ‘Opton’ microscope-photometer. Depending on the nature of the original plant material and on the degree of biochemical alteration, the maceral reflectance increases from the group of liptinite (RO (%) = 0.06–0.28) towards the group of huminite (RO (%) = 0.29–0.52) and the group of inertinite (RO (%) = 0.84–3.05). The action of geochemical factors did not result in obliteration of the differences in the reflectance of macerals from the huminite group. 相似文献
929.
930.