The eight datasets of the summer (June-August) surface sensible heat (SH) flux over the Tibetan Plateau (TP) are compared on the time scales of the climatology,interannual variability and linear trend during 1980-2006...The eight datasets of the summer (June-August) surface sensible heat (SH) flux over the Tibetan Plateau (TP) are compared on the time scales of the climatology,interannual variability and linear trend during 1980-2006.These data sets include five reanalyses (National Center for Environmental Prediction reanalysis,NCEPR1 and NCEPR2,NCEP climate forecast system reanalysis,CFSR,Japanese 25-year reanalysis,JRA,and European Centre for Medium Range Weather Forecasts reanalysis,ERA40),two land surface model outputs (Noah model data of Global Land Data Assimilation System version 2,G2_Noah,and Simple Biosphere version 2 output by Yang et al.,YSiB2),and estimated SH based on China Meteorological Administration (CMA) station observations,ObCh.The results suggest that the summer SH on the TP differs from one dataset to another due to different inputs and calculations.Climatologically,the ERA40 and JRA distribute rather uniformly while the other six products show similar regional disparities,that is,larger in the west than in the east and stronger in the north and the south than in the middle of the plateau.The mean magnitude of the SH averaged over the 76 stations above the TP varies considerably among each dataset with the difference of more than 20 W m?2 between the maximum (G2_Noah) and minimum (ObCh).Nevertheless,they are consistent in the interannual variability and mostly show a significant decreasing trend corresponding to the weakening surface wind speed,in spite of the distinct trend for the ground-air temperature difference among the different data sets.These two consistencies indicate the particular availability of the SH products,which is helpful to the relevant climate dynamics research.展开更多
Hepatic hemangiomas need to be treated surgically in cases where they are accompanied with symptoms, have a risk of rupture, or are hardly distinguishable from malignancy. The present authors conducted embolization of...Hepatic hemangiomas need to be treated surgically in cases where they are accompanied with symptoms, have a risk of rupture, or are hardly distinguishable from malignancy. The present authors conducted embolization of the right hepatic artery one day before an operation for a huge hemangioma accompanied with symptoms and confirmed a decrease in its size. The authors performed a right trisegmentectomy through a J-shape incision, using a thoracoabdominal approach, and safely removed a giant hemangioma of 32.0 cm × 26.5 cm × 8.0 cm in size and 2300 g in weight. Even for inexperienced surgeons, a J-shape incision with a thoracoabdominal approach is considered a safe and useful method when right-side hepatectomy is required for a large mass in the right liver.展开更多
Discharge in the source region of the Yellow River significantly declined after 1990.China Meteorological Administration(CMA) data show that precipitation in this region was low in the 1990s but returned to above norm...Discharge in the source region of the Yellow River significantly declined after 1990.China Meteorological Administration(CMA) data show that precipitation in this region was low in the 1990s but returned to above normal after 2002;in recent decades there has been rapid warming of surface air,moistening and wind speed decrease.To investigate the influences of recent climatic changes on the water budget,this study simulates the surface water budget at CMA stations within and surrounding the source region during 1960-2006,using an improved land surface model.Results indicate that the spatial pattern of precipitation change is an important factor(except for precipitation amount and intensity) in determining the response of runoff to precipitation changes.Low runoff in the 1990s was consistent with precipitation amount and intensity.The recovery of precipitation after 2002 is mainly from increased precipitation in the dry area of the source region.Evaporation was mainly limited by water availability in this dry area,and thus most of the precipitation increase was evaporated.By contrast,energy availability was a more important influence on evaporation in the wet area.There was more evaporation in the wet area because of rapid warming,although precipitation amount partly decreased and partly increased,contributing to the reduction of runoff after 2002.This control on evaporation and its response,together with the modified spatial pattern of precipitation,produced a water budget unfavorable for runoff generation in the source region during recent years.展开更多
Wind power resources are abundant in China,especially in northern China and eastern coastal areas of China.Nevertheless,wind energy has intermittent and unstable characteristics,which leads to random power output and ...Wind power resources are abundant in China,especially in northern China and eastern coastal areas of China.Nevertheless,wind energy has intermittent and unstable characteristics,which leads to random power output and limits the large-scale utilization of wind energy resources.It has been shown that geographically dispersed wind plants have obvious spatiotemporal offsetting effect.Power output from each individual site exhibits the power ups and downs.However,when we simulate power lines connecting sites over a certain region,the output from them changes slowly and rarely reaches either very low or full power.Hence using the spatiotemporal complementarity of wind resources effectively is highly beneficial to the smoothing of power supply.This paper investigates the spatiotemporal complementarity of wind resources in China based on the relevant data of wind energy resources,which are offered by China Meteorological Administration(CMA).展开更多
基金supported by Major Projects of the Knowledge Innovation Program of Chinese Academy of Sciences (Grant No. KZCX2-YW-Q11-01)the National Basic Research Program of China (Grant No. 2010CB950403)National Natural Science Foundation of China (Grant Nos. 40925015,40810059005 and 40821092)
文摘The eight datasets of the summer (June-August) surface sensible heat (SH) flux over the Tibetan Plateau (TP) are compared on the time scales of the climatology,interannual variability and linear trend during 1980-2006.These data sets include five reanalyses (National Center for Environmental Prediction reanalysis,NCEPR1 and NCEPR2,NCEP climate forecast system reanalysis,CFSR,Japanese 25-year reanalysis,JRA,and European Centre for Medium Range Weather Forecasts reanalysis,ERA40),two land surface model outputs (Noah model data of Global Land Data Assimilation System version 2,G2_Noah,and Simple Biosphere version 2 output by Yang et al.,YSiB2),and estimated SH based on China Meteorological Administration (CMA) station observations,ObCh.The results suggest that the summer SH on the TP differs from one dataset to another due to different inputs and calculations.Climatologically,the ERA40 and JRA distribute rather uniformly while the other six products show similar regional disparities,that is,larger in the west than in the east and stronger in the north and the south than in the middle of the plateau.The mean magnitude of the SH averaged over the 76 stations above the TP varies considerably among each dataset with the difference of more than 20 W m?2 between the maximum (G2_Noah) and minimum (ObCh).Nevertheless,they are consistent in the interannual variability and mostly show a significant decreasing trend corresponding to the weakening surface wind speed,in spite of the distinct trend for the ground-air temperature difference among the different data sets.These two consistencies indicate the particular availability of the SH products,which is helpful to the relevant climate dynamics research.
文摘Hepatic hemangiomas need to be treated surgically in cases where they are accompanied with symptoms, have a risk of rupture, or are hardly distinguishable from malignancy. The present authors conducted embolization of the right hepatic artery one day before an operation for a huge hemangioma accompanied with symptoms and confirmed a decrease in its size. The authors performed a right trisegmentectomy through a J-shape incision, using a thoracoabdominal approach, and safely removed a giant hemangioma of 32.0 cm × 26.5 cm × 8.0 cm in size and 2300 g in weight. Even for inexperienced surgeons, a J-shape incision with a thoracoabdominal approach is considered a safe and useful method when right-side hepatectomy is required for a large mass in the right liver.
基金supported by the National Basic Research Program of China (2009CB421405)
文摘Discharge in the source region of the Yellow River significantly declined after 1990.China Meteorological Administration(CMA) data show that precipitation in this region was low in the 1990s but returned to above normal after 2002;in recent decades there has been rapid warming of surface air,moistening and wind speed decrease.To investigate the influences of recent climatic changes on the water budget,this study simulates the surface water budget at CMA stations within and surrounding the source region during 1960-2006,using an improved land surface model.Results indicate that the spatial pattern of precipitation change is an important factor(except for precipitation amount and intensity) in determining the response of runoff to precipitation changes.Low runoff in the 1990s was consistent with precipitation amount and intensity.The recovery of precipitation after 2002 is mainly from increased precipitation in the dry area of the source region.Evaporation was mainly limited by water availability in this dry area,and thus most of the precipitation increase was evaporated.By contrast,energy availability was a more important influence on evaporation in the wet area.There was more evaporation in the wet area because of rapid warming,although precipitation amount partly decreased and partly increased,contributing to the reduction of runoff after 2002.This control on evaporation and its response,together with the modified spatial pattern of precipitation,produced a water budget unfavorable for runoff generation in the source region during recent years.
文摘Wind power resources are abundant in China,especially in northern China and eastern coastal areas of China.Nevertheless,wind energy has intermittent and unstable characteristics,which leads to random power output and limits the large-scale utilization of wind energy resources.It has been shown that geographically dispersed wind plants have obvious spatiotemporal offsetting effect.Power output from each individual site exhibits the power ups and downs.However,when we simulate power lines connecting sites over a certain region,the output from them changes slowly and rarely reaches either very low or full power.Hence using the spatiotemporal complementarity of wind resources effectively is highly beneficial to the smoothing of power supply.This paper investigates the spatiotemporal complementarity of wind resources in China based on the relevant data of wind energy resources,which are offered by China Meteorological Administration(CMA).
