Stainless steels are the promising candidate materials for bipolar plate of polymer electrolyte membrane fuel cell (PEMFC) due to their high conductivity,low material and production costs,ease stamping manufacture and...
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Stainless steels are the promising candidate materials for bipolar plate of polymer electrolyte membrane fuel cell (PEMFC) due to their high conductivity,low material and production costs,ease stamping manufacture and superior mechanical ***,their interfacial contact resistances (ICR) are high and corrosion resistances are not at desired levels for real PEMFC working conditions.
Cadmium sulphide (CdS) is a promising material to produce hydrogen because of its narrow band gap, abundance and simple preparation *** we know, element-doped CdS and special nanostructure of CdS has high efficient pe...
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Cadmium sulphide (CdS) is a promising material to produce hydrogen because of its narrow band gap, abundance and simple preparation *** we know, element-doped CdS and special nanostructure of CdS has high efficient performance for hydrogen production, while CdS alone demonstrated extremely low photocatalytic activity for the production of hydrogen under visible light ***, much attention has been focused on CdS morphologies controlling, nanostructures doping and surface modifacation.
As a layered-structure semiconductor material with wide band gap, MoO3 has been considered to be a promising candidate for application in gas ***, gas sensor based on MoO3 have been found to have a response towards va...
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As a layered-structure semiconductor material with wide band gap, MoO3 has been considered to be a promising candidate for application in gas ***, gas sensor based on MoO3 have been found to have a response towards various gases such as H2S, NO2, NH3, trimethylamine, formaldehyde and H2 in the temperature range of 300-600 ℃.Although MoO3 films and nanorods are not sensitive to ethanol gas, it is found that the ultralong MoO3 nanobelts have a good sensitivity and selectivity to ethanol gas in our works.
Quantum dots sensitized solar cells (QDSSCs) have been attracted much attention as the next generation photovoltaic devices, due to the size-effect, high absorption coefficient and multiple excitation generation of qu...
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Quantum dots sensitized solar cells (QDSSCs) have been attracted much attention as the next generation photovoltaic devices, due to the size-effect, high absorption coefficient and multiple excitation generation of quantum dots (QDs).Recently, Mn-CdS/CdSe and CuInS2/Mn-CdS sensitized solar cells has been ***, the performance of the solar cells is still limited by the transfer barrier of the photo-induced electrons from ***, the single crystalline nanorods, nanowires and nanotubes arrays structure have been widely prepared to improve the electron *** order to effectively enhance the efficiency, the nanowire structure is expected to be employed in both photo-anodes and counter electrodes for QDSSCs fabrication.
TiO2 hollow structure materials had become one of the hot spots because of their low density, high specific surface areas, and good photocatalytic *** now, there were lots of works focused on them, such as their exten...
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TiO2 hollow structure materials had become one of the hot spots because of their low density, high specific surface areas, and good photocatalytic *** now, there were lots of works focused on them, such as their extensive application in catalysis, pharmacy, sensing device, photon transmission and the basis material of ***, the drawbacks which are out control of nanoparticles phases on the surface, raw materials wasted and visible region absorption of its structure doesn't make it get better development in the field of photocatalysis research.
Flow channel in bipolar plate for PEMFC has the founction of transporting the fuel and oxygen and *** process for flow channel on metallic bipolar plates is an economic and convenient method for mass *** is extremely ...
Flow channel in bipolar plate for PEMFC has the founction of transporting the fuel and oxygen and *** process for flow channel on metallic bipolar plates is an economic and convenient method for mass *** is extremely important to predict and prevent the tearing,wrinkling,thinning,skid mark and spring back in stamping *** this study,finite element method is used to predict the imperfection and analyze the strain and thickness variation during the stamping process.
Recently, inverse opal structures, which have many potential applications in catalysts, separations, sensors, bioscience and photonics for their unique advantages such as highly ordered pore structure, large specific ...
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Recently, inverse opal structures, which have many potential applications in catalysts, separations, sensors, bioscience and photonics for their unique advantages such as highly ordered pore structure, large specific surface areas. The common synthesis strategy for inverse opal films is colloidal crystal templating method. This method included three steps: (1) synthesizing the hexagonal ordered-closed colloidal crystals;(2) immersing the liquid mental precursor into the voids of the templates;(3) removing the templates by calcination or etching. Several fabrication methods for ZnO inverse opal film synthesis have been reported including atomic layer deposition, chemical vapor deposition and electrodeposition. However the large-scale ZnO inverse opal film synthesized by sol-gel method has seldom been reported and the mechanism on the photocatalytic activity of ZnO inverse opal film is still needed to be explored. In this work, different sizes of P(St-MMA-SPMAP) colloidal spheres were used as templates and Zn(NO 3 ) 2 as precursor to obtain the ZnO inverse opal film. The products have been characterized by XRD, SEM, and UV/Vise spectrometer. The morphology of the products is highly organized, dense and large-scale and the crystalline of the products is hexagonal wurtzite structure. The different sizes of ZnO inverse opal films have been applied for the photodecomposition of the rhodamine B (RhB) in water. Through the results it can be concluded that the photocatalytic activity has been correlated with the pore sizes of the ZnO inverse opal film, which ascribe to the slow photon effect. When the stop-band edge matches the irradiation wavelength, it can increase the path length of light by enhancing the light absorption of the material resulting in enhanced photocatalytic activity.
Ceramic particle-reinforced metal-matrix composites(MMCp) exhibit strong size effect due to the development of geometrically necessary dislocations(GND),when the characteristic length scale associated with non-uniform...
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Ceramic particle-reinforced metal-matrix composites(MMCp) exhibit strong size effect due to the development of geometrically necessary dislocations(GND),when the characteristic length scale associated with non-uniform plastic deformation is on the order of *** size-dependent response is commonly attributed to the density of geometrically necessary dislocations(GNDs),which represents an extra storage of dislocations required to accommodate the lattice curvature and contribute to the work hardening of the matrix material. At present,crystal plasticity theories,strain gradient theories and discrete dislocation theories can capture such size *** almost all of these theories are based on this assumption that GNDs have no upper limit and can increase *** reality,the GND density cannot be very large,and never exceed a maximum allowable GND density,since the strong repulsive forces between GNDs push dislocations to *** nano-indentation experiments have confirmed that once the indentation depth reaches the order of nanometers,the conventional accumulation way of GNDs is *** ***(Huang Y,Zhang F,Hwang KC,Nix WD, Pharr GM,Feng G.J Mech Phys Solids 2006;54:1668.) introduced the maximum allowable GND density max to capture the GND density by a piecewise analytic model based on the nano-indentation *** on the maximum allowable GND density,the flow stress based on Taylor hardening law can be modified as Eq.(1). In the paper,the Taylor-based nonlocal theory(TNT) of plasticity involving maximum allowable GND density is implemented to investigate the size-dependence of aluminum matrix reinforced by SiC particles(SiCp/Al composites).To various particle shape and size, the evolution of GND of SiCp/AI composites predicted by TNT plasticity involving maximum allowable GND density is *** tensile loading,distribution characteristics of GND density and average effective GND density are also quantitatively described. Numerical
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