【目的】储层岩石渗透率通常呈各向异性分布,探究储层岩石渗透率各向异性对含水层压缩空气储能(compressed air energy storage in aquifers,CAESA)系统季节性运行性能的影响。【方法】建立CAESA系统概念模型和三维井群-储库数值模型,拟...【目的】储层岩石渗透率通常呈各向异性分布,探究储层岩石渗透率各向异性对含水层压缩空气储能(compressed air energy storage in aquifers,CAESA)系统季节性运行性能的影响。【方法】建立CAESA系统概念模型和三维井群-储库数值模型,拟定3种储层渗透率各向异性分布方案,运用T2WELL/EOS3数值模拟软件,研究CAESA系统在季节性运行模式和渗透率各向异性条件下的流体传质和传热过程。【结果】储层渗透率各向异性会影响井筒-储层中的气相运移、流体交互和温压传递过程,进而影响系统的储能效率;当渗透率横纵比从2.0升高至10.0时,井筒的最大压力降低2.79 MPa,抽采阶段井口的最高温度升高2.06℃,井口两相流现象出现的时间从系统运行第435 d提前至第410 d,系统储能效率从89.8%降低至60.1%。【结论】对于渗透率各向异性程度较高的储层,可以通过增加初始气囊注入量或在后期进行补气来增加系统支撑压力,还可以采用注浆等工程手段,建立人造低渗边界以优化储层条件,提升系统储能效率。展开更多
A three-dimensional baroclinic shelf sea model’s numerical simulation of the South China Sea (SCS) middle and deep layer circulation structure showed that: 1. In the SCS middle and deep layer, a southward boundary cu...A three-dimensional baroclinic shelf sea model’s numerical simulation of the South China Sea (SCS) middle and deep layer circulation structure showed that: 1. In the SCS middle and deep layer, a southward boundary current exists along the east shore of the Indo-China Peninsula all year long. A cyclonic eddy (gyre) is formed by the current in the above sea areas except in the middle layer in spring, when an anticyclonic eddy exists on the eastern side of the current. In the deep layer, a large-scale anticyclonic eddy often exists in the sea areas between the Zhongsha Islands and west shore of southern Luzon Island. 2. In the middle layer in summer and autumn, and in the deep layer in autumn and winter, there is an anticyclonic eddy (gyre) in the northeastern SCS, while in the middle layer in winter and spring, and in the deep layer in spring and summer, there is a cyclonic one. 3. In the middle layer, there is a weak northeastward current in the Nansha Trough in spring and summer, while in autumn and winter it evolves into an anticyclonic eddy (gyre), which then spreads westward to the whole western Nansha Islands sea areas.展开更多
Compacted loess is widely used as fills of road embankments in loess regions of northern China.Generally, densely-compacted loess can satisfy the requirements of embankment strength and postconstruction deformation. H...Compacted loess is widely used as fills of road embankments in loess regions of northern China.Generally, densely-compacted loess can satisfy the requirements of embankment strength and postconstruction deformation. However, uneven subsidence, pavement cracks and other related damages can affect the integrity of loess subgrade after several years of operation,and even cause some hazards, especially in North China, where the strong freeze-thaw erosion occurs. In this study, cyclic freeze-thaw tests for both densely and loosely compacted loess samples were performed to determine the variation in engineering properties such as volume, void ratio, collapsible settlement,microstructure, and the related mechanisms were addressed. The experimental results showed that an obvious water migration and redistribution occurred within the samples during freeze-thaw cycles. Ice lenses and fissures could be identified in the upper frozen layers of the samples. After freeze-thaw cycles,the dry densities of the upper layers of samples changed significantly due to strong freeze-thaw erosion. The dry densities decreased for the dense sample and increased for the loose sample. It can be found that dense samples become loose, while loose samples became dense with the increasing number of freeze-thaw cycles. Their related void ratios changed reversely. Both void ratios tended to fall into a certain range, which verified the concept of a residual void ratio proposed by Viklander. The loosening process of densely compacted samples involves the formation of large pores, volume increase and density reduction as well as the related changes in mechanical properties because freeze-thaw cycles may be important contribution to problems of loess road embankments.Adverse effects of freeze-thaw cycles, therefore,should be taken into account in selecting loess parameters for the stability evaluation of road embankment in seasonally frozen ground regions.展开更多
Riverine carbon flux is an important component of the global carbon cycle. The spatial and temporal variations of organic and inorganic carbon were examined during both dry and wet seasons in the Yellow River estuary....Riverine carbon flux is an important component of the global carbon cycle. The spatial and temporal variations of organic and inorganic carbon were examined during both dry and wet seasons in the Yellow River estuary. Concentrations of dissolved organic carbon （DOC） and dissolved inorganic carbon （DIC） in the Yellow River during dry seasons were higher than those during wet seasons. The effective concentrations of DOC （CDOC＊） were higher than the observed DOC at zero salinity. This input of DOC in the Yellow River estuary was due to sediment desorption processes in low salinity regions. In contrast to DOC, the effective concen- trations of DIC were 10% lower than the DIC measured at freshwater end, and the loss of DIC was caused by CaCO3 precipitation in low salinity region, Particulate organic carbon （POC） and particulate inorganic carbon （PIC） contents of the particles stabilized to constant values （0.5%：t：0.05% and 1.8%--0.2%, respectively） within the turbidity maximum zone （TMZ） and showed no noticeable seasonal variations. A rapid drop of PIC and rise of POC occurred simultaneously outside the TMZ due to an intense dilution of riv- erine inorganic-rich particles being transported into a pool of aquatic organic-poor particles outside the TMZ. Annually, the Yellow River transported 6.95× 10^5 t of DIC, 0.64× 10^5 t of DOC, 78.58× 10^5 t of PIC and 2.29× 10^5 t of POC to the sea.展开更多
In seasonal frozen soil region,the engineering geological properties of loess-like soil will be deteriorated after freeze-thaw cycles.Through the freeze-thaw cycle experiment of remolded loess-like soil,under differen...In seasonal frozen soil region,the engineering geological properties of loess-like soil will be deteriorated after freeze-thaw cycles.Through the freeze-thaw cycle experiment of remolded loess-like soil,under different freezing temperatures,the authors carried out freeze-thaw cycle tests for 3 times and 20 times,respectively.With mercury intrusion porosimetry and granulometric analysis,from the micro-structure,the authors studied the law that freeze-thaw cycle times and frozen temperature effect on the variation of microscopic pore of loesslike soil.This result can provide theoretical basis for comprehensive treatment of problems in the construction of the project in seasonal frozen loess-like soil region.展开更多
文摘【目的】储层岩石渗透率通常呈各向异性分布,探究储层岩石渗透率各向异性对含水层压缩空气储能(compressed air energy storage in aquifers,CAESA)系统季节性运行性能的影响。【方法】建立CAESA系统概念模型和三维井群-储库数值模型,拟定3种储层渗透率各向异性分布方案,运用T2WELL/EOS3数值模拟软件,研究CAESA系统在季节性运行模式和渗透率各向异性条件下的流体传质和传热过程。【结果】储层渗透率各向异性会影响井筒-储层中的气相运移、流体交互和温压传递过程,进而影响系统的储能效率;当渗透率横纵比从2.0升高至10.0时,井筒的最大压力降低2.79 MPa,抽采阶段井口的最高温度升高2.06℃,井口两相流现象出现的时间从系统运行第435 d提前至第410 d,系统储能效率从89.8%降低至60.1%。【结论】对于渗透率各向异性程度较高的储层,可以通过增加初始气囊注入量或在后期进行补气来增加系统支撑压力,还可以采用注浆等工程手段,建立人造低渗边界以优化储层条件,提升系统储能效率。
文摘A three-dimensional baroclinic shelf sea model’s numerical simulation of the South China Sea (SCS) middle and deep layer circulation structure showed that: 1. In the SCS middle and deep layer, a southward boundary current exists along the east shore of the Indo-China Peninsula all year long. A cyclonic eddy (gyre) is formed by the current in the above sea areas except in the middle layer in spring, when an anticyclonic eddy exists on the eastern side of the current. In the deep layer, a large-scale anticyclonic eddy often exists in the sea areas between the Zhongsha Islands and west shore of southern Luzon Island. 2. In the middle layer in summer and autumn, and in the deep layer in autumn and winter, there is an anticyclonic eddy (gyre) in the northeastern SCS, while in the middle layer in winter and spring, and in the deep layer in spring and summer, there is a cyclonic one. 3. In the middle layer, there is a weak northeastward current in the Nansha Trough in spring and summer, while in autumn and winter it evolves into an anticyclonic eddy (gyre), which then spreads westward to the whole western Nansha Islands sea areas.
基金supported by the National Key Basic Research Program of China(973 Program)(Grant No.2012CB026106)National Natural Science Foundation of China(No.41672310)+3 种基金the Science and Technology Major Project of Gansu Province(Grant No.143GKDA007)National key research and development program(2016YFC0802103)the West Light Foundation of CAS for Dr.G.Y.Li,Project of the State Key Laboratory of Frozen Soils Engineering of CAS(Grant No.SKLFSE-ZY-16)the STS research project of the Cold and Arid Regions Environmental and Engineering Research Institute(HHS-TSS-STS-1502)
文摘Compacted loess is widely used as fills of road embankments in loess regions of northern China.Generally, densely-compacted loess can satisfy the requirements of embankment strength and postconstruction deformation. However, uneven subsidence, pavement cracks and other related damages can affect the integrity of loess subgrade after several years of operation,and even cause some hazards, especially in North China, where the strong freeze-thaw erosion occurs. In this study, cyclic freeze-thaw tests for both densely and loosely compacted loess samples were performed to determine the variation in engineering properties such as volume, void ratio, collapsible settlement,microstructure, and the related mechanisms were addressed. The experimental results showed that an obvious water migration and redistribution occurred within the samples during freeze-thaw cycles. Ice lenses and fissures could be identified in the upper frozen layers of the samples. After freeze-thaw cycles,the dry densities of the upper layers of samples changed significantly due to strong freeze-thaw erosion. The dry densities decreased for the dense sample and increased for the loose sample. It can be found that dense samples become loose, while loose samples became dense with the increasing number of freeze-thaw cycles. Their related void ratios changed reversely. Both void ratios tended to fall into a certain range, which verified the concept of a residual void ratio proposed by Viklander. The loosening process of densely compacted samples involves the formation of large pores, volume increase and density reduction as well as the related changes in mechanical properties because freeze-thaw cycles may be important contribution to problems of loess road embankments.Adverse effects of freeze-thaw cycles, therefore,should be taken into account in selecting loess parameters for the stability evaluation of road embankment in seasonally frozen ground regions.
基金supported by the National Basic Research Program of China (No. 2002CB412504)
文摘Riverine carbon flux is an important component of the global carbon cycle. The spatial and temporal variations of organic and inorganic carbon were examined during both dry and wet seasons in the Yellow River estuary. Concentrations of dissolved organic carbon （DOC） and dissolved inorganic carbon （DIC） in the Yellow River during dry seasons were higher than those during wet seasons. The effective concentrations of DOC （CDOC＊） were higher than the observed DOC at zero salinity. This input of DOC in the Yellow River estuary was due to sediment desorption processes in low salinity regions. In contrast to DOC, the effective concen- trations of DIC were 10% lower than the DIC measured at freshwater end, and the loss of DIC was caused by CaCO3 precipitation in low salinity region, Particulate organic carbon （POC） and particulate inorganic carbon （PIC） contents of the particles stabilized to constant values （0.5%：t：0.05% and 1.8%--0.2%, respectively） within the turbidity maximum zone （TMZ） and showed no noticeable seasonal variations. A rapid drop of PIC and rise of POC occurred simultaneously outside the TMZ due to an intense dilution of riv- erine inorganic-rich particles being transported into a pool of aquatic organic-poor particles outside the TMZ. Annually, the Yellow River transported 6.95× 10^5 t of DIC, 0.64× 10^5 t of DOC, 78.58× 10^5 t of PIC and 2.29× 10^5 t of POC to the sea.
文摘In seasonal frozen soil region,the engineering geological properties of loess-like soil will be deteriorated after freeze-thaw cycles.Through the freeze-thaw cycle experiment of remolded loess-like soil,under different freezing temperatures,the authors carried out freeze-thaw cycle tests for 3 times and 20 times,respectively.With mercury intrusion porosimetry and granulometric analysis,from the micro-structure,the authors studied the law that freeze-thaw cycle times and frozen temperature effect on the variation of microscopic pore of loesslike soil.This result can provide theoretical basis for comprehensive treatment of problems in the construction of the project in seasonal frozen loess-like soil region.
