Based on the data of core description and sporopollen analysis,the gradual evolution of deltas in vertical direction and transition of channel types in the MPE3 block of the eastern Venezuela Basin have been surveyed ...Based on the data of core description and sporopollen analysis,the gradual evolution of deltas in vertical direction and transition of channel types in the MPE3 block of the eastern Venezuela Basin have been surveyed by seismic phase and well logging facies interpretation.The results show that due to the great sea level rise,the sedimentary system of the Miocene Oficina Formation in the MPE3 block shifted from the distal-source sandy braided river delta to tide-affected delta,and eventually to tide-dominated delta.Vertically,during the early stage of sedimentation of Oficina Formation,the distributary channels of the delta were dominated by braided river channels.While in the later stage,as the tidal effect was gradually intensified,the channel changed from braided channel to meandering channel.On plane,as a result of differential transgression,sedimentary framework and distribution of sand bodies vary across the study area.Compared with the eastern part,the western part has more braided channels,larger channel bars,less developments of distributary bay and higher ratio of sand to mud.Whereas the braided channels in the south are larger than those in the north.It is the first time we pointed out the impact of marine transgression differences on the sedimentary facies distribution and river type transition in the study area.Factors like the structural and paleogeomorphological change,sea level variation,supply of sediments have strong influence on the evolution of sedimentary system and distribution of sandbodies.It is predicted that the major sandbody is more developed in the central south,which can guide the subsequent horizontal well development.展开更多
We have used the Yellow River Delta （Dongying section） as our study area to address the project of ＂Three Networks Greening＂ （TNG）. With the use of GIS technology and from an ecological point of view, an optimal...We have used the Yellow River Delta （Dongying section） as our study area to address the project of ＂Three Networks Greening＂ （TNG）. With the use of GIS technology and from an ecological point of view, an optimal allocation scheme of land resources is constructed and applied to guide the adjustment of land resources. Given this scheme, we have calculated that the area of land suitable for forest and shrubs without greening is 2256 km^2. Simultaneously, acting on the layout of the TNG project, afforestation site types are prepared and improved. Soil types, microrelief, salinity and underwater levels are combined as major classification factors and irrigation conditions as a reference to classify sites into eight types. In this way, land suitable for forest and grass is afforested given particular planting patterns. Finally, by overlaying this forestry site type map with the TNG plan map, some suggestions and strategies are proposed and used to direct the TNG project. An ecological oasis of the Yellow River Delta should be the result.展开更多
In the framework of the Thomas–Fermi(TF) approach, a model for the p-type double-δ-doped(DDD) system in Ga As is presented. This model, unlike other works in the literature, takes into account that the Poisson equat...In the framework of the Thomas–Fermi(TF) approach, a model for the p-type double-δ-doped(DDD) system in Ga As is presented. This model, unlike other works in the literature, takes into account that the Poisson equation associated with the system is nonlinear. The electronic structure is calculated for heavy and light holes. The changes in the electronic structure result of the distance d between the doped layers are studied. In particular, the relative absorption coefficient as well as the relative refractive index change is calculated as a function of the incident photon energy for heavy holes. The effect of the interlayer distance exhibits, in the absorption coefficient, a red shift of the peak position and a decrease in amplitude when the distance increases. In addition, the relative refractive index change node has a red shift as well as the interlayer distance increases. The calculations show that the effect of the separation between layers has a greater influence on the linear terms. These results are very important for theoretical calculations and engineering of optical and electronic devices based in δ-doped Ga As.展开更多
基金supported by the Important National Science Technology Specific Projects (number 2016ZX05031-001)
文摘Based on the data of core description and sporopollen analysis,the gradual evolution of deltas in vertical direction and transition of channel types in the MPE3 block of the eastern Venezuela Basin have been surveyed by seismic phase and well logging facies interpretation.The results show that due to the great sea level rise,the sedimentary system of the Miocene Oficina Formation in the MPE3 block shifted from the distal-source sandy braided river delta to tide-affected delta,and eventually to tide-dominated delta.Vertically,during the early stage of sedimentation of Oficina Formation,the distributary channels of the delta were dominated by braided river channels.While in the later stage,as the tidal effect was gradually intensified,the channel changed from braided channel to meandering channel.On plane,as a result of differential transgression,sedimentary framework and distribution of sand bodies vary across the study area.Compared with the eastern part,the western part has more braided channels,larger channel bars,less developments of distributary bay and higher ratio of sand to mud.Whereas the braided channels in the south are larger than those in the north.It is the first time we pointed out the impact of marine transgression differences on the sedimentary facies distribution and river type transition in the study area.Factors like the structural and paleogeomorphological change,sea level variation,supply of sediments have strong influence on the evolution of sedimentary system and distribution of sandbodies.It is predicted that the major sandbody is more developed in the central south,which can guide the subsequent horizontal well development.
基金supported by the National Science Foundation of China (Grant No.40771172)the Main Direction Program of Knowledge In-novation of the Chinese Academy of Sciences (kzcx2-yw-308)
文摘We have used the Yellow River Delta （Dongying section） as our study area to address the project of ＂Three Networks Greening＂ （TNG）. With the use of GIS technology and from an ecological point of view, an optimal allocation scheme of land resources is constructed and applied to guide the adjustment of land resources. Given this scheme, we have calculated that the area of land suitable for forest and shrubs without greening is 2256 km^2. Simultaneously, acting on the layout of the TNG project, afforestation site types are prepared and improved. Soil types, microrelief, salinity and underwater levels are combined as major classification factors and irrigation conditions as a reference to classify sites into eight types. In this way, land suitable for forest and grass is afforested given particular planting patterns. Finally, by overlaying this forestry site type map with the TNG plan map, some suggestions and strategies are proposed and used to direct the TNG project. An ecological oasis of the Yellow River Delta should be the result.
基金Project supported by PISA 2016–1 UJAT and PRODEP Folio UJAT-245 of México
文摘In the framework of the Thomas–Fermi(TF) approach, a model for the p-type double-δ-doped(DDD) system in Ga As is presented. This model, unlike other works in the literature, takes into account that the Poisson equation associated with the system is nonlinear. The electronic structure is calculated for heavy and light holes. The changes in the electronic structure result of the distance d between the doped layers are studied. In particular, the relative absorption coefficient as well as the relative refractive index change is calculated as a function of the incident photon energy for heavy holes. The effect of the interlayer distance exhibits, in the absorption coefficient, a red shift of the peak position and a decrease in amplitude when the distance increases. In addition, the relative refractive index change node has a red shift as well as the interlayer distance increases. The calculations show that the effect of the separation between layers has a greater influence on the linear terms. These results are very important for theoretical calculations and engineering of optical and electronic devices based in δ-doped Ga As.
