In this paper,various ZnO nanostructures,such as rods,flowers were grown on indium-tin-oxide(ITO) substrates by hydrothermal growth at low temperature,using the different concentrations of equimolar(1:1) zinc nitr...
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In this paper,various ZnO nanostructures,such as rods,flowers were grown on indium-tin-oxide(ITO) substrates by hydrothermal growth at low temperature,using the different concentrations of equimolar(1:1) zinc nitrate(Zn(NO)·6HO) and methenamine(CHN) mixed as precursors solution,and adding ammonia solution to control the pH ***,XRD were utilized to characterize morphologies and crystal structures of *** was indicated that the concentration of precursor solution leads to the significantly changes in the nanostructured *** possible growth mechanism is discussed in this work.
A nitrogen-doped titania nanoparticle film on an ITO substrate was successfully obtained by gas phase *** a nitrogen-doped titania nanoparticle film on an ITO substrate shows efficient at the responsivity under the vi...
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A nitrogen-doped titania nanoparticle film on an ITO substrate was successfully obtained by gas phase *** a nitrogen-doped titania nanoparticle film on an ITO substrate shows efficient at the responsivity under the visible light *** photo-anode with N-doped was fabricated using nanocrystalline pastes and their N719-sensitization led to a short-circuit photocurrent density of 3.95 mA/cm and a solar energy conversion efficiency of 1.72%under air-mass 1.5 global and illumination with the intensity of 100 mW/cm(AM 1.5G,100 raW/cm).
In this paper we use electrochemical deposition to grow a layer of gray compact film on the steel,characterized the product by X-ray diffraction(XRD) we find the ZnO cone-like rods and hierarchical rod-like nanostruct...
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In this paper we use electrochemical deposition to grow a layer of gray compact film on the steel,characterized the product by X-ray diffraction(XRD) we find the ZnO cone-like rods and hierarchical rod-like nanostructure are all preferentially growing along the C-axis,which is confirmed by the direction of crystal growth in the transmission electron microscope(TEM) *** the TEM image we find the hierarchical ZnO nanorods have an in situ growth in the high-energy electron beam irradiation,which makes the specific surface area increase and to some extent enhance the absorption of light energy.
ZnO was a promising n-type conductive semiconductor material for dye-sensitized solar cellsStable and efficient preparation of high quality p-type ZnO films became the main difficulty in current researchIn this paper,...
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ZnO was a promising n-type conductive semiconductor material for dye-sensitized solar cellsStable and efficient preparation of high quality p-type ZnO films became the main difficulty in current researchIn this paper,a nitrogen-doped ZnO columnar film on an indium tin oxide(ITO)substrate was successfully obtained by gas phase methodThe absorption of visible light was improved by nitrogen-doped ZnO columnar filmsThis experiment provided a good strategy for the full utilization of solar energy
In this paper,we mainly talk about two kinds of ZnO nanostructure materials which are rod and flower structure by hydrothermal growth as photoanode of quantum dot sensitized solar cells(QDSSCs)Using chemical bath de...
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In this paper,we mainly talk about two kinds of ZnO nanostructure materials which are rod and flower structure by hydrothermal growth as photoanode of quantum dot sensitized solar cells(QDSSCs)Using chemical bath deposition to assemble CdS quantum dots onto ZnO nanostructure materials,and after different CBD cycles we could get the cell parameters of different CBD cycles respectively in their I-V curves,from which we could see it is the flower structure that has the highest efficiency which is 0346%after 9 CBD cycles and the short-circuit current is 288 mA/cmTherefore,we could see that ZnO flower structure has a potential application in solar cell devices as the photoelectrode to gain higher photoelectric conversion efficiency(PCE)
Palladium-doped nano-gamma-Fe2O3 films were printed on Al2O3 substrates by screen printing injecting hybrid technology. X-ray diffraction and scanning electron microscopy techniques were used to characterize the phase...
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Palladium-doped nano-gamma-Fe2O3 films were printed on Al2O3 substrates by screen printing injecting hybrid technology. X-ray diffraction and scanning electron microscopy techniques were used to characterize the phase structures and morphologies of the films, respectively. The sensitivity of the films to 100 ppm formaldehyde in air was investigated. The surface adsorption and reaction process between Pd-doped nano-gamma-Fe2O3 films and formaldehyde was studied by in situ diffuse reflectance Fourier transform infrared spectroscopy (DRIFTS) at different temperatures. Dioxymethylene, formate ions, polyoxymethylene, and adsorbed formaldehyde were detected when the Pd-doped nano-gamma-Fe2O3 films were exposed to 100 ppm formaldehyde at different temperatures. A possible mechanism of the reaction process is discussed.
A fermentation process using Clostridium tyrobutyricum immobilized in a fibrous-bed bioreactor (FBB) was developed for butyric acid production from sugarcane bagasse (SCB) hydrolysate. SCB was first treated with dilut...
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A fermentation process using Clostridium tyrobutyricum immobilized in a fibrous-bed bioreactor (FBB) was developed for butyric acid production from sugarcane bagasse (SCB) hydrolysate. SCB was first treated with dilute acid and then hydrolyzed with cellulases. The hydrolysate containing glucose and xylose was used as carbon source for the fermentation without detoxification. The bacterium was able to grow at a specific growth rate of similar to 0.06 h(-1) in media containing 15-20% (w/v) SCB in serum bottles. In batch cultures in the FBB, both glucose and xylose in the SCB hydrolysate were simultaneously converted to butyrate with a high yield (0.45-0.54 g/g sugar) and productivity (0.48-0.60 g/L h). A final butyrate concentration of 20.9 g/L was obtained in a fed-batch culture, with an overall productivity of 0.51 g/L h and butyrate yield of 0.48 g/g sugar consumed. This work demonstrated the feasibility of using SCB as a low-cost feedstock to produce butyric acid. (C) 2012 Elsevier Ltd. All rights reserved.
Enantiopure sulfoxides can be prepared via the asymmetric oxidation of sulfides using sulfide monooxygenases. The n-octane-water biphasic system was chosen for the bio-oxidation of a water-insoluble phenyl methyl sulf...
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Enantiopure sulfoxides can be prepared via the asymmetric oxidation of sulfides using sulfide monooxygenases. The n-octane-water biphasic system was chosen for the bio-oxidation of a water-insoluble phenyl methyl sulfide (PMS) by Rhodococcus sp. CCZU10-1. In this n-octane-water system, the optimum reaction conditions were obtained. (S)-phenyl methyl sulfoxide ((S)-PMSO) with > 99.9 % enantiomeric excess formed at 55.3 mM in the n-octane-water biphasic system. Using fed-batch method, a total of 118 mM (S)-PMSO accumulated in 1-L reaction mixture after the 7th feed, and no (R)-PMSO and sulfone were detected. Moreover, Rhodococcus sp. CCZU10-1 displayed fairly good activity and enantioselectivity toward other sulfides. In conclusion, Rhodococcus sp. CCZU10-1 is a promising biocatalyst for synthesizing highly optically active sulfoxides.
As the forward directivity and fling effect characteristics of the near-fault ground motions, seismic response of structures in the near field of a rupturing fault can be significantly different from those observed in...
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As the forward directivity and fling effect characteristics of the near-fault ground motions, seismic response of structures in the near field of a rupturing fault can be significantly different from those observed in the far field. The unique characteristics of the near-fault ground motions can cause considerable damage during an earthquake. This paper presents results of a study aimed at evaluating the near-fault and far-fault ground motion effects on nonlinear dynamic response and seismic damage of concrete gravity dams including dam-reservoir-foundation interaction. For this purpose, 10 as-recorded earthquake records which display ground motions with an apparent velocity pulse are selected to represent the near-fault ground motion characteristics. The earthquake ground motions recorded at the same site from other events that the epicenter far away from the site are employed as the far-fault ground motions. The Koyna gravity dam, which is selected as a numerical application, is subjected to a set of as-recorded near-fault and far-fault strong ground motion records. The Concrete Damaged Plasticity (CDP) model including the strain hardening or softening behavior is employed in nonlinear analysis. Nonlinear dynamic response and seismic damage analyses of the selected concrete dam subjected to both near-fault and far-fault ground motions are performed. Both local and global damage indices are established as the response parameters. The results obtained from the analyses of the dam subjected to each fault effect are compared with each other. It is seen from the analysis results that the near-fault ground motions, which have significant influence on the dynamic response of dam-reservoir-foundation systems, have the potential to cause more severe damage to the dam body than far-fault ground motions. (C) 2013 Elsevier Ltd. All rights reserved.
The seismic crack propagation of concrete gravity dams with initial cracks at the upstream and downstream faces has rarely been studied during strong earthquakes. In this paper, a numerical scheme based on the extende...
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The seismic crack propagation of concrete gravity dams with initial cracks at the upstream and downstream faces has rarely been studied during strong earthquakes. In this paper, a numerical scheme based on the extended finite element method (XFEM), which has been widely used for the analysis of crack growth, is presented to deal with the numerical prediction of crack propagation in concrete gravity dams. The validity of the algorithm is discussed by comparing results obtained from the proposed XFEM with those reported in the literature. For this purpose, the cracking process and final crack profile of Koyna dam during the 1967 Koyna earthquake are simulated numerically by employing the XFEM. The computed distribution of cracking damage is consistent with the actual condition and the results of model test and available methods in literature, which verifies the validity of the calculation model. Subsequently, the Koyna dam with single and multiple initial cracks is also analyzed using the proposed approach, which is investigated to evaluate the seismic crack propagation of the concrete gravity dam with initial cracks. The effects of initial cracks on the crack propagation and seismic response of the concrete gravity dam are discussed. (C) 2013 Elsevier Ltd. All rights reserved.
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