Hydrogen production by biomass gasification using solar energy is a promising approach for overcoming the drawbacks of fossil fuel utilization, but the storage of discontinuous solar flux is a critical issue for conti...
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A series of CdS and CdS/CNTs photocatalysts were successfully prepared by hydrothermal method and they were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), UV-visible optical absorption s...
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Heterojunction structures are attracting lots of attention for enhancing the electron injection across the interface. The ZnS/ZnO one-dimensional heterojunction film was firstly prepared via a chemical sulfidization f...
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The photoelectrochemical (PEC) properties of heterostructured CdS/BiVO 4 and BiVO4/CdS film electrodes on conducting glass for hydrogen production under visible light were investigated. These two types heterostructure...
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The uniform ZnO/ZnS/CdS core-shell nanorod film was synthesized by a two-step ion-exchange method. The crystal structure, morphology, composition and optical property of as-prepared films were characterized by X-ray d...
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To realize highly efficient heat dissipation of electronics, a loop heat pipe (LHP) with a flat evaporator was designed to study its operation characteristics at the tilt angles of 0°, 30°, 45°, 60°...
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To realize highly efficient heat dissipation of electronics, a loop heat pipe (LHP) with a flat evaporator was designed to study its operation characteristics at the tilt angles of 0°, 30°, 45°, 60°, 90° with an improved evaporator structure and a well arranged pipes which can reduce heat loss due to back conduction and improve inner flow performance. The results show that the LHP with inclination has a lower power to start up than the horizontal one, and at the same heat load, the operation temperature of the evaporator is much lower and the system is easier to reach a steady state with less temperature oscillations. However, there is slight difference in operating performance for the LHP at different title angles. The thermal resistance decreases with an increase in the heat load and a steady state occurs at last. The thermal resistance is larger for the horizontal case than that for the inclination case at the same heat load. The thermal resistances are very different at different tilt angles at low heat load, but the difference is small at high heat load.
Introduction Liver cirrhosis generally occurs with the hemodynamic changes during the portal vein hypertension and finally leads to the atrophy of the right lobe of the liver and hepatic failure[1].According to the he...
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Introduction Liver cirrhosis generally occurs with the hemodynamic changes during the portal vein hypertension and finally leads to the atrophy of the right lobe of the liver and hepatic failure[1].According to the hemodynamic changes,a hypothesis has been proposed that the liver volume is related to the istribution of blood from the splenic vein(SV)that involves nutrition from spleen and pancreas[2,3].The objective of the present paper is to simulate the blood flow in real models of portal vein hypertension and validate the hypothesis using computational fluid dynamics(CFD)*** This study includes 2 patients with liver cirrhosis and a set of 4 normal subjects.
Ignition delay times of dimethyl ether (DME) and propane blends were measured in a shock tube at varied DME blending ratios (0%, 20%, 50%, 80%, 100%), equivalence ratios (0.5, 1.0, 2.0), temperatures (1100-1500 K) and...
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Ignition delay times of dimethyl ether (DME) and propane blends were measured in a shock tube at varied DME blending ratios (0%, 20%, 50%, 80%, 100%), equivalence ratios (0.5, 1.0, 2.0), temperatures (1100-1500 K) and pressures of 20 atm. Mechanism validations were conducted using different chemical kinetic models. A new C5 chemical model with DME sub-model was developed and it can well predict experimental ignition delay times of pure propane, DME and their blends. Experimental and numerical results show that with the decrease of temperature, the ignition delay times increase and the activation energy decreases slightly. With the increase of equivalence ratio, ignition delay times increase for propane and decrease for DME in this study. Ignition delay times decrease with the increase of DME blending ratio and the decrease rates become larger with the increase of equivalence ratio. The peak values of H and OH mole fraction increase with increasing the DME blending ratio, and they promote the ignition of DME/propane blends. Sensitivity analysis shows that the reaction rates of R1 and R353 increase with the increase of DME blending ratio and induces the decrease of the ignition delay time of DME/propane blends.
Ignition delays of stoichiometric syngas mixtures (H2/CO/O 2) diluted with argon were measured behind the reflected shock wave at pressures of 0.2, 1.0 and 2.0 MPa, temperature from 896 to 1264 K, equivalence ratios o...
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Ignition delays of stoichiometric syngas mixtures (H2/CO/O 2) diluted with argon were measured behind the reflected shock wave at pressures of 0.2, 1.0 and 2.0 MPa, temperature from 896 to 1264 K, equivalence ratios of 0.3, 1.0 and 1.5. The effect of non-ideal conditions on ignition delays, determined by pressure trace behind the reflected shock wave (pressure rise rate is approximately 4.22%/ms), was used to calculate. Six available mechanisms were selected to simulate the ignition delays of syngas mixtures, the predicted results were compared with the measured ones. These results indicated that there is no mechanism can calculate accurately ignition delays over all testing conditions. The ignition delays predicted with three mechanisms (Davis 2005, USC ver 2.0, NUI nc5-49) are close to the measured ones. Using the Davis mechanism to analyse reaction kinetics, the achieved results showed that the reaction R1 dominates the ignition process of syngas. The reaction R31 plays an important promoted role in ignition process of syngas mixtures.
An Eulerian-Lagrangian numerical simulation is performed to study aeolian sand transport in a wind tunnel. The evolutions of three parameters, sand mass flux, decay rate of sand mass flux profile and sand particle mea...
An Eulerian-Lagrangian numerical simulation is performed to study aeolian sand transport in a wind tunnel. The evolutions of three parameters, sand mass flux, decay rate of sand mass flux profile and sand particle mean horizontal velocity with time, are investigated. The results show that: Sand mass flux takes more time to reach the saturated state than the last two parameters. First, we prove the evolution with time in the simulation is similar to the evolution in the length direction in a wind tunnel and then the experimental data from unsaturated wind tunnel can be used in the quantitative comparison with simulated saturated results. Second, detailed comparison is carried out. The tendency of sand mass flux is consistent with the experimental data. Decay rate of sand mass flux profile and sand particle mean horizontal velocity fit the experimental data well especially for cases of small free stream wind velocity, and the deviation is getting larger with the increasing of free stream wind velocity.
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