A set of experiments was designed to study the power performance of a c-Si and a pc-Si cell when exposed to various levels of high illumination. The light concentration ratio, C, ranges from C 〈 1, up to C ≈ 26. An ...A set of experiments was designed to study the power performance of a c-Si and a pc-Si cell when exposed to various levels of high illumination. The light concentration ratio, C, ranges from C 〈 1, up to C ≈ 26. An experimental set up was built for the purposes of this project. PV cell modeling is outlined in this paper for isc, Voc and the PV cell temperature, Tc, which predicts those quantities. There the behaviour of the two PV-cells at both transient out steady state conditions is studied. Predicted values are compared against measured ones. A comparison of the experimental values against the theoretically predicted ones is performed for the range C 〈 1 to C ≈ 26. Power recovery is tried through heat removal from both sides of the PV-cells by air forced flow. Experiments show recovery whose degree is close to 100% for low C values. On the other hand, as C grows higher, P~ starts decreasing too. PV cell temperatures reached up to 136 ℃ for C = 25. This is a challenge as reduction of temperature delivers a good amount of heat, in the cogeneration effect, while it has a positive impact to power recovery of the PV cell.展开更多
Using the Greenberg-Hasting cellular automata model, we study the properties of target waves in excitable media under the no-flux boundary conditions. For the system has only one excited state, the computer simulation...Using the Greenberg-Hasting cellular automata model, we study the properties of target waves in excitable media under the no-flux boundary conditions. For the system has only one excited state, the computer simulation and analysis lead to the conclusions that, the number of refractory states does not influence the wave-front speed; the wave- front speed decreases as the excitation threshold increases and increases as the neighbor radius increases; the period of target waves is equal to the number of cell states; the excitation condition for target waves is that the wave-front speed must be bigger than half of the neighbor radius.展开更多
This paper discussed impact of temperature on the size distribution in preparing ultrafine silica from rice husk.The samples prepared were analyzed with infrared spectrum,and the relation between the particle size and...This paper discussed impact of temperature on the size distribution in preparing ultrafine silica from rice husk.The samples prepared were analyzed with infrared spectrum,and the relation between the particle size and intensity of characteristic absorption peak of IR at center around 1 100 cm-1 was disscussed with the baseline method.Results show that when the temperature is 650 ℃ and roasting time is 11 h,at optimal reaction conditions,the size distribution of the ultrafine silica powder prepared is relatively concentrated,and the average particle size is 199.5 nm.Moreover,the characteristic absorption band of IR is broadening gradually along with particle size decreasing.展开更多
文摘A set of experiments was designed to study the power performance of a c-Si and a pc-Si cell when exposed to various levels of high illumination. The light concentration ratio, C, ranges from C 〈 1, up to C ≈ 26. An experimental set up was built for the purposes of this project. PV cell modeling is outlined in this paper for isc, Voc and the PV cell temperature, Tc, which predicts those quantities. There the behaviour of the two PV-cells at both transient out steady state conditions is studied. Predicted values are compared against measured ones. A comparison of the experimental values against the theoretically predicted ones is performed for the range C 〈 1 to C ≈ 26. Power recovery is tried through heat removal from both sides of the PV-cells by air forced flow. Experiments show recovery whose degree is close to 100% for low C values. On the other hand, as C grows higher, P~ starts decreasing too. PV cell temperatures reached up to 136 ℃ for C = 25. This is a challenge as reduction of temperature delivers a good amount of heat, in the cogeneration effect, while it has a positive impact to power recovery of the PV cell.
基金Supported by the National Natural Science Foundation of China under Grant Nos. 10562001 and 10765002
文摘Using the Greenberg-Hasting cellular automata model, we study the properties of target waves in excitable media under the no-flux boundary conditions. For the system has only one excited state, the computer simulation and analysis lead to the conclusions that, the number of refractory states does not influence the wave-front speed; the wave- front speed decreases as the excitation threshold increases and increases as the neighbor radius increases; the period of target waves is equal to the number of cell states; the excitation condition for target waves is that the wave-front speed must be bigger than half of the neighbor radius.
文摘This paper discussed impact of temperature on the size distribution in preparing ultrafine silica from rice husk.The samples prepared were analyzed with infrared spectrum,and the relation between the particle size and intensity of characteristic absorption peak of IR at center around 1 100 cm-1 was disscussed with the baseline method.Results show that when the temperature is 650 ℃ and roasting time is 11 h,at optimal reaction conditions,the size distribution of the ultrafine silica powder prepared is relatively concentrated,and the average particle size is 199.5 nm.Moreover,the characteristic absorption band of IR is broadening gradually along with particle size decreasing.
