A novel coating technique was developed for controlling Pyrite oxidation. The technique invo1ved leachingpyrite particles with a solution containing low concentrations of phosphate and hydrogen peroxide. Duringthe lea...A novel coating technique was developed for controlling Pyrite oxidation. The technique invo1ved leachingpyrite particles with a solution containing low concentrations of phosphate and hydrogen peroxide. Duringthe leaching process, the iron released from pyrite by hydrogen proxide was precipitated by phosphate as aferric phosphate coating. This coating was shown to be able to effectively prevent Pyrite from oxidation and itcould be established at the expense of only surface portions of Pyrite. The emergence of this technique couldprovide a unique potential route for abating acid mine drainage and reclaiming sulfide-containing degradedmining land.展开更多
A new approach for noninvasively tracing brain white matter fiber tracts is presented using diffusion tensor magnetic resonance imaging (DT-MRI) data. This technique is based on successive anisotropic diffusion simula...A new approach for noninvasively tracing brain white matter fiber tracts is presented using diffusion tensor magnetic resonance imaging (DT-MRI) data. This technique is based on successive anisotropic diffusion simulations over the human brain, which are utilized to construct three dimensional diffusion fronts. The fiber pathways are determined by evaluating the distance and orientation from fronts to their corresponding diffusion seeds. Real DT-MRI data are used to demonstrate the tracking scheme. It is shown that several major white matter fiber pathways can be reproduced noninvasively, with the tract branching being allowed. Since the diffusion simulation,which is a truly physical phenomenon reflecting the underlying architecture of cerebral tissues, makes full use of the entire diffusion tensor data, the proposed approach is expected to enhance robustness and reliability of the DT-MRI based fiber tracking techniques in white matter fiber reconstruction.展开更多
Objective: The correlation between various formative conditions and the pore characterizations of the anodic alumina membrane is investigated to seek the optimal conditions for the formation of anodic alumina membrane...Objective: The correlation between various formative conditions and the pore characterizations of the anodic alumina membrane is investigated to seek the optimal conditions for the formation of anodic alumina membrane. Methods: High purity aluminum foils are used as the starting materials. The anodization is conducted in three types of electrolytes, 3% sulfuric acid, 5% sulfuric acid and 2.7% oxalic acid, respectively, with different voltages at 0℃ for 48h. The characterizations of the pore size, the effective porosity and the pore porosity are observed and determined by scanning electron microscopy. The hydraulic conductances of the membranes are measured to confirm that the pores are open and evaluate the permselectivity of the membranes. Results: The experimental result shows that the ordered pore arrays are obtained for oxidation under our experimental conditions. With the increasing of the voltage, the pore size and pore porosity increased significantly ( P < 0.05) , while the effective porosity decreased significantly ( P < 0.05 ) with the same electrolyte. The pore size formed in 3% sulfuric acid or 5% sulfuric acid is much smaller than in 2.7% oxalic acid as an electrolyte. The hydraulic conductance of anodic alumina membrane that formed under our experimental condition is higher than those of the membranes are available currently used in clinical. Conclusion: The results suggest that the optimal conditions for the formation of anodic alumina membrane that used in hemodialysis are in 3% or 5% sulfuric acid with 12.5V to 17.5V at 0℃ for 48h.展开更多
A novel approach has been developed to determine the amount of residual water in human erythrocyte at room temperature by electronic particle counter. Nacl solutions of 13 osmolalities were prepared and the equilibriu...A novel approach has been developed to determine the amount of residual water in human erythrocyte at room temperature by electronic particle counter. Nacl solutions of 13 osmolalities were prepared and the equilibrium cell volumes in which were measured one by one.The isotonic volume, V0, was obtained under the isotonic condition. The mean RBC volumes of 5 donors at each osmolality were fitted according to Boyle van’t Hoff relationship, and the osmotically inactive volume, Vb, of erythrocyte was then determined. The results show that Vb50% V0. More importantly, the final cell volume with regard to the solution of the highest concentration found to be kept at about 0.5 V0. The difference between these two volumes is unconspicuous. According to the published data that non-water volume of human erythrocyte is about 28.3% of its isotonic volume, residual water of human erythrocyte can be gained by subtracting V dry from Vf, that is V rw =21.7% V0. Then it was concluded that the residual water of human lays in 2 states, one is bound water, and the other is free water.展开更多
A novel theoretical model for mass transfer of hollow fiber bundles in hemodialyzers is presented. In the model, a hemodialyzer is considered as a porous zone which is composed of two non-interpenetrating porous flow ...A novel theoretical model for mass transfer of hollow fiber bundles in hemodialyzers is presented. In the model, a hemodialyzer is considered as a porous zone which is composed of two non-interpenetrating porous flow zones. Firstly, the dialysate side (shell side) is thought as a porous medium zone. Then by solidifying the dialysate flow zone and the occupied zone by hollow fiber membrane, the rest zone of hemodialyzer (i.e. blood side or lumen side) is con-sidered as a porous medium zone too. Finally, the interface of the two flow zones is the fiber membrane through which mass transfer is performed. The dialysate and blood flows are all described by Navier-Stokes equations with Darcy momentum source terms. Kedem-Katchalsky equations as other source terms are added into Navier-Stokes equations to simulate the permeating flux through the membrane. All equations must be coupled together in the process of com-puting. The model is validated by the experimental data in literature. The simulative results show that the predicted clearances agree well with the experimental data, and the model in this paper is better than other models for the fore-cast of clearance.展开更多
We report on the growth of geometric feature tuned semiconductor nanotubes on a transparent substrate through the application of an anodic aluminum oxide membrane-assisted method. Three-dimensional nanotube solar cell...We report on the growth of geometric feature tuned semiconductor nanotubes on a transparent substrate through the application of an anodic aluminum oxide membrane-assisted method. Three-dimensional nanotube solar cells are developed in which semiconductor absorbers are not only used to fill the inner core of the nanotubes, but also to replace the membrane and to fill the intertube space between the nanotubes. The nanotube solar cells generate and separate carriers in three dimensions, namely, inside the cores of the nanotubes, in the intertube space between the nanotubes along the radial direction, and above the nanotubes along the axial direction. In preliminary experiments conducted to demonstrate the potential of this approach, nanotube CdS-CdTe solar cells were fabricated. CdS nanotubes with an inner diameter, wall thickness and intertube spacing of 35, 20, and 35 nm, respectively, were grown; the porosity and CdS nanotube density were 36.5% and 2.26 × 10^10 nanotubes/cm^2, respectively. These features of CdS nanotubes enable more efficient carrier collection because of the reduced recombination, especially in those cases in which the minority carrier lifetime is short, thus resulting in a diffusion length of less than 100 nm. Nanotube CdS-CdTe solar cells exhibit a wide and strong spectral response and quantum efficiency, indicating enhanced light absorption and carrier generation and collection. Without the benefit of an antireflection coating, the cells exhibited a wide and strong spectral response of quantum efficiency, and a short current density of 25.5 mA/cm^2, an open circuit voltage of 750 mV, and a power conversion efficiency of 10.7% under 1-sun illumination. The materials and electro-optical characterizations indicated well-defined junction and interface behavior in these 3D nanotube solar cell configurations.展开更多
Agricultural trade between the U.S. and China is very important for both countries. Focusing on the potential of China's agricultural products entering the U.S. markets, this research introduced the development of...Agricultural trade between the U.S. and China is very important for both countries. Focusing on the potential of China's agricultural products entering the U.S. markets, this research introduced the development of agricultural trade between the U.S. and China and analyzed the impacts of the U.S.-China bilateral trade agreement and China's WTO membership on agricultural trade between the two countries. The authors also examined current and potential competitiveness of China's agricultural products and provided suggestions to increase China's agricultural exports to the United States.展开更多
文摘A novel coating technique was developed for controlling Pyrite oxidation. The technique invo1ved leachingpyrite particles with a solution containing low concentrations of phosphate and hydrogen peroxide. Duringthe leaching process, the iron released from pyrite by hydrogen proxide was precipitated by phosphate as aferric phosphate coating. This coating was shown to be able to effectively prevent Pyrite from oxidation and itcould be established at the expense of only surface portions of Pyrite. The emergence of this technique couldprovide a unique potential route for abating acid mine drainage and reclaiming sulfide-containing degradedmining land.
文摘A new approach for noninvasively tracing brain white matter fiber tracts is presented using diffusion tensor magnetic resonance imaging (DT-MRI) data. This technique is based on successive anisotropic diffusion simulations over the human brain, which are utilized to construct three dimensional diffusion fronts. The fiber pathways are determined by evaluating the distance and orientation from fronts to their corresponding diffusion seeds. Real DT-MRI data are used to demonstrate the tracking scheme. It is shown that several major white matter fiber pathways can be reproduced noninvasively, with the tract branching being allowed. Since the diffusion simulation,which is a truly physical phenomenon reflecting the underlying architecture of cerebral tissues, makes full use of the entire diffusion tensor data, the proposed approach is expected to enhance robustness and reliability of the DT-MRI based fiber tracking techniques in white matter fiber reconstruction.
文摘Objective: The correlation between various formative conditions and the pore characterizations of the anodic alumina membrane is investigated to seek the optimal conditions for the formation of anodic alumina membrane. Methods: High purity aluminum foils are used as the starting materials. The anodization is conducted in three types of electrolytes, 3% sulfuric acid, 5% sulfuric acid and 2.7% oxalic acid, respectively, with different voltages at 0℃ for 48h. The characterizations of the pore size, the effective porosity and the pore porosity are observed and determined by scanning electron microscopy. The hydraulic conductances of the membranes are measured to confirm that the pores are open and evaluate the permselectivity of the membranes. Results: The experimental result shows that the ordered pore arrays are obtained for oxidation under our experimental conditions. With the increasing of the voltage, the pore size and pore porosity increased significantly ( P < 0.05) , while the effective porosity decreased significantly ( P < 0.05 ) with the same electrolyte. The pore size formed in 3% sulfuric acid or 5% sulfuric acid is much smaller than in 2.7% oxalic acid as an electrolyte. The hydraulic conductance of anodic alumina membrane that formed under our experimental condition is higher than those of the membranes are available currently used in clinical. Conclusion: The results suggest that the optimal conditions for the formation of anodic alumina membrane that used in hemodialysis are in 3% or 5% sulfuric acid with 12.5V to 17.5V at 0℃ for 48h.
基金This research is supported by NSFC(5 0 10 6 0 16 ) ,NSF of Anhui Province(0 0 0 4 75 2 0 ,0 30 4 3717)
文摘A novel approach has been developed to determine the amount of residual water in human erythrocyte at room temperature by electronic particle counter. Nacl solutions of 13 osmolalities were prepared and the equilibrium cell volumes in which were measured one by one.The isotonic volume, V0, was obtained under the isotonic condition. The mean RBC volumes of 5 donors at each osmolality were fitted according to Boyle van’t Hoff relationship, and the osmotically inactive volume, Vb, of erythrocyte was then determined. The results show that Vb50% V0. More importantly, the final cell volume with regard to the solution of the highest concentration found to be kept at about 0.5 V0. The difference between these two volumes is unconspicuous. According to the published data that non-water volume of human erythrocyte is about 28.3% of its isotonic volume, residual water of human erythrocyte can be gained by subtracting V dry from Vf, that is V rw =21.7% V0. Then it was concluded that the residual water of human lays in 2 states, one is bound water, and the other is free water.
文摘A novel theoretical model for mass transfer of hollow fiber bundles in hemodialyzers is presented. In the model, a hemodialyzer is considered as a porous zone which is composed of two non-interpenetrating porous flow zones. Firstly, the dialysate side (shell side) is thought as a porous medium zone. Then by solidifying the dialysate flow zone and the occupied zone by hollow fiber membrane, the rest zone of hemodialyzer (i.e. blood side or lumen side) is con-sidered as a porous medium zone too. Finally, the interface of the two flow zones is the fiber membrane through which mass transfer is performed. The dialysate and blood flows are all described by Navier-Stokes equations with Darcy momentum source terms. Kedem-Katchalsky equations as other source terms are added into Navier-Stokes equations to simulate the permeating flux through the membrane. All equations must be coupled together in the process of com-puting. The model is validated by the experimental data in literature. The simulative results show that the predicted clearances agree well with the experimental data, and the model in this paper is better than other models for the fore-cast of clearance.
基金Acknowle dgements This work was supported in part by grants from the National Science Foundation （Nos. NSF-NIRT-ECS- 0609064 and NSF-EPCOR EPS-0447479） and by grants from the Kentucky Science and Engineering Foundation （Nos. KSEF-148-502-02-27 and KSEF-148-502-03-68）. The authors would like to thank PV measurements, Inc for quantum efficiency measurement.
文摘We report on the growth of geometric feature tuned semiconductor nanotubes on a transparent substrate through the application of an anodic aluminum oxide membrane-assisted method. Three-dimensional nanotube solar cells are developed in which semiconductor absorbers are not only used to fill the inner core of the nanotubes, but also to replace the membrane and to fill the intertube space between the nanotubes. The nanotube solar cells generate and separate carriers in three dimensions, namely, inside the cores of the nanotubes, in the intertube space between the nanotubes along the radial direction, and above the nanotubes along the axial direction. In preliminary experiments conducted to demonstrate the potential of this approach, nanotube CdS-CdTe solar cells were fabricated. CdS nanotubes with an inner diameter, wall thickness and intertube spacing of 35, 20, and 35 nm, respectively, were grown; the porosity and CdS nanotube density were 36.5% and 2.26 × 10^10 nanotubes/cm^2, respectively. These features of CdS nanotubes enable more efficient carrier collection because of the reduced recombination, especially in those cases in which the minority carrier lifetime is short, thus resulting in a diffusion length of less than 100 nm. Nanotube CdS-CdTe solar cells exhibit a wide and strong spectral response and quantum efficiency, indicating enhanced light absorption and carrier generation and collection. Without the benefit of an antireflection coating, the cells exhibited a wide and strong spectral response of quantum efficiency, and a short current density of 25.5 mA/cm^2, an open circuit voltage of 750 mV, and a power conversion efficiency of 10.7% under 1-sun illumination. The materials and electro-optical characterizations indicated well-defined junction and interface behavior in these 3D nanotube solar cell configurations.
文摘Agricultural trade between the U.S. and China is very important for both countries. Focusing on the potential of China's agricultural products entering the U.S. markets, this research introduced the development of agricultural trade between the U.S. and China and analyzed the impacts of the U.S.-China bilateral trade agreement and China's WTO membership on agricultural trade between the two countries. The authors also examined current and potential competitiveness of China's agricultural products and provided suggestions to increase China's agricultural exports to the United States.
