In this paper,acoustic emission（AE） and digital image correlation methods were applied to monitor interface cracking in thermal barrier coatings under compression.The interface failure process can be identifie via i...In this paper,acoustic emission（AE） and digital image correlation methods were applied to monitor interface cracking in thermal barrier coatings under compression.The interface failure process can be identifie via its AE features,including buckling,delamination incubation and spallation.According to the Fourier transformation of AE signals,there arefourdifferentfailuremodes：surfaceverticalcracks,opening and sliding interface cracks,and substrate deformation.The characteristic frequency of AE signals from surface vertical cracks is 0.21 MHz,whilst that of the two types of interface cracks are 0.43 and 0.29 MHz,respectively.The energy released of the two types of interface cracks are 0.43 and 0.29 MHz,respectively.Based on the energy released from cracking and the AE signals,a relationship is established between the interface crack length and AE parameters,which is in good agreement with experimental results.展开更多
In this work, a comprehensive model that takes the phenomenon of carrier thermionic-emission within the frame work of a diffusion theory of current conducting into account in the type Ⅱ hetero-junction Cd Te solar ce...In this work, a comprehensive model that takes the phenomenon of carrier thermionic-emission within the frame work of a diffusion theory of current conducting into account in the type Ⅱ hetero-junction Cd Te solar cell is developed. According to this model, it is found that the total current flowing through the Cd Te solar cell is limited by the thermionic process for very thin quasi-neutral regions and limited by the diffusion process for the reverse case. In future research of the Cd Te solar cell, such an approach may enable the determination of the boundary conditions for all doping profiles and computation of the conversion efficiency, etc.展开更多
Daily and annual average atmospheric environmental capacity coefficient(A-value) sequences for China's Mainland are calculated from hourly data recorded at 378 ground stations over 1975–2014. A-values at differen...Daily and annual average atmospheric environmental capacity coefficient(A-value) sequences for China's Mainland are calculated from hourly data recorded at 378 ground stations over 1975–2014. A-values at different recurrence intervals are calculated by fitting the sequences to Pearson type III distribution curves. Based on these A-values and source-sink balance(reference concentration 100 μg m^(-3)), atmospheric environmental capacities at the recurrence intervals are calculated for all of China's Mainland and each provincial administrative region. The climate average atmospheric environmental capacity reference value for the entire mainland is 2.169×10~7 t yr^(-1). An urban atmospheric load index is defined for analyses of the impact of population density on the urban atmospheric environment. Analyses suggest that this index is also useful for differentiating whether air quality changes are attributable to varying meteorological conditions or variations of artificial emission rate.Equations guiding the control of unorganized emission sources are derived for preventing air quality deterioration during urban expansion and population concentration.展开更多
基金supported by the National Natural Science Foundation of China (Grants 11472237,11002122,51172192,and 11272275)
文摘In this paper,acoustic emission（AE） and digital image correlation methods were applied to monitor interface cracking in thermal barrier coatings under compression.The interface failure process can be identifie via its AE features,including buckling,delamination incubation and spallation.According to the Fourier transformation of AE signals,there arefourdifferentfailuremodes：surfaceverticalcracks,opening and sliding interface cracks,and substrate deformation.The characteristic frequency of AE signals from surface vertical cracks is 0.21 MHz,whilst that of the two types of interface cracks are 0.43 and 0.29 MHz,respectively.The energy released of the two types of interface cracks are 0.43 and 0.29 MHz,respectively.Based on the energy released from cracking and the AE signals,a relationship is established between the interface crack length and AE parameters,which is in good agreement with experimental results.
文摘In this work, a comprehensive model that takes the phenomenon of carrier thermionic-emission within the frame work of a diffusion theory of current conducting into account in the type Ⅱ hetero-junction Cd Te solar cell is developed. According to this model, it is found that the total current flowing through the Cd Te solar cell is limited by the thermionic process for very thin quasi-neutral regions and limited by the diffusion process for the reverse case. In future research of the Cd Te solar cell, such an approach may enable the determination of the boundary conditions for all doping profiles and computation of the conversion efficiency, etc.
基金supported by the National Natural Science Foundation of China (Grant No. 41405136)
文摘Daily and annual average atmospheric environmental capacity coefficient(A-value) sequences for China's Mainland are calculated from hourly data recorded at 378 ground stations over 1975–2014. A-values at different recurrence intervals are calculated by fitting the sequences to Pearson type III distribution curves. Based on these A-values and source-sink balance(reference concentration 100 μg m^(-3)), atmospheric environmental capacities at the recurrence intervals are calculated for all of China's Mainland and each provincial administrative region. The climate average atmospheric environmental capacity reference value for the entire mainland is 2.169×10~7 t yr^(-1). An urban atmospheric load index is defined for analyses of the impact of population density on the urban atmospheric environment. Analyses suggest that this index is also useful for differentiating whether air quality changes are attributable to varying meteorological conditions or variations of artificial emission rate.Equations guiding the control of unorganized emission sources are derived for preventing air quality deterioration during urban expansion and population concentration.
