Based on crystallographic theory, there are 63 kinds of polytypes of 13H long-period stacking order （LPSO） structure, 126 kinds of polytypes of 14H LPSO structure, 120 kinds of polytypes of 39R LPSO structure, and 2...Based on crystallographic theory, there are 63 kinds of polytypes of 13H long-period stacking order （LPSO） structure, 126 kinds of polytypes of 14H LPSO structure, 120 kinds of polytypes of 39R LPSO structure, and 223 kinds of polytypes of 42R LPSO structure in a hexagonal close-packed （HCP） system, and their stacking sequences and space groups have been derived in detail. The result provides a theoretical explanation for the various polytypes of the LPSO structure.展开更多
At present, the Topographic Index Model （TOPMODEL） has been recommended for integration in Land Surface Models （LSMs）. But, the applicable scope of the original TOPMODEL （OTOP） is limited because the OTOP deriva...At present, the Topographic Index Model （TOPMODEL） has been recommended for integration in Land Surface Models （LSMs）. But, the applicable scope of the original TOPMODEL （OTOP） is limited because the OTOP derivation relies on three fundamental but unrealistic assumptions. In this paper, several versions of a generalized TOPMODEL （GTOP）, which relax some unrealistic assumptions involved in OTOP, are presented, and the theoretical derivationsn to obtain these modifications are demonstrated in detail. Specifically, the extension for the OTOP applicability comes down to following three basic cases： （1） Give up the assumption of spatially uniform recharge rate to the groundwater and let the rate be spatially varying, （2） Keep same original exponential distribution profile of hydraulic conductivity used in OTOP but change the saturated hydraulic conductivity and effective soil depth from spatial constants in OTOP to spatially variable quantities; and （3） Extend the original exponential distribution profile of hydraulic conductivity to more general power law distribution profile of hydraulic conductivity together with spatially variable saturated hydraulic conductivity and effective soil depth. Finally, a brief numerical sensitivity study based on one version of GTOP using an exponential distribution profile for soil hydraulic conductivity is conducted. This shows the heterogeneous effects of the effective soil depth, saturated hydraulic conductivity, at ground surface and groundwater recharge rate on hydrological processes and serves as an example application of GTOP to a heterogeneous catchment.展开更多
基金Project supported by the National Natural Science Foundation of China(Grant Nos.51371130,51171130,and 51271134)the Fundamental Research Funds for the Central Universities,Chinathe Open Research Fund of Science and Technology on High Strength Structural Materials Laboratory,Central South University,China
文摘Based on crystallographic theory, there are 63 kinds of polytypes of 13H long-period stacking order （LPSO） structure, 126 kinds of polytypes of 14H LPSO structure, 120 kinds of polytypes of 39R LPSO structure, and 223 kinds of polytypes of 42R LPSO structure in a hexagonal close-packed （HCP） system, and their stacking sequences and space groups have been derived in detail. The result provides a theoretical explanation for the various polytypes of the LPSO structure.
基金supported by National Natural Science Foundation of China (Grant Nos.40235043 and 40605024)the Natural Science Foundation of Shandong Province (Grant No. Q2005E01)
文摘At present, the Topographic Index Model （TOPMODEL） has been recommended for integration in Land Surface Models （LSMs）. But, the applicable scope of the original TOPMODEL （OTOP） is limited because the OTOP derivation relies on three fundamental but unrealistic assumptions. In this paper, several versions of a generalized TOPMODEL （GTOP）, which relax some unrealistic assumptions involved in OTOP, are presented, and the theoretical derivationsn to obtain these modifications are demonstrated in detail. Specifically, the extension for the OTOP applicability comes down to following three basic cases： （1） Give up the assumption of spatially uniform recharge rate to the groundwater and let the rate be spatially varying, （2） Keep same original exponential distribution profile of hydraulic conductivity used in OTOP but change the saturated hydraulic conductivity and effective soil depth from spatial constants in OTOP to spatially variable quantities; and （3） Extend the original exponential distribution profile of hydraulic conductivity to more general power law distribution profile of hydraulic conductivity together with spatially variable saturated hydraulic conductivity and effective soil depth. Finally, a brief numerical sensitivity study based on one version of GTOP using an exponential distribution profile for soil hydraulic conductivity is conducted. This shows the heterogeneous effects of the effective soil depth, saturated hydraulic conductivity, at ground surface and groundwater recharge rate on hydrological processes and serves as an example application of GTOP to a heterogeneous catchment.
