The irrational land use is one of the main reasons for the soil erosion and nutrient loss in the loess hilly area of China. In this project, 4 types of typical land use structure of sustain ment for about 15 years in ...The irrational land use is one of the main reasons for the soil erosion and nutrient loss in the loess hilly area of China. In this project, 4 types of typical land use structure of sustain ment for about 15 years in the loess hill slope are selected to study the effect of land use structure on the distribution of soil nutrients. From hill bottom to hill top, the patterns of land use types are:, grassland-slope farmland-forest, slope farmland-grassland-forest, terrace-grassland-forest and slope farmland-forest-grassland. By measuring the contents of the total N, total P, available N, available P and organic matter of soils, the results show that the land use structure types of slope farmland-grassland-forest and terrace-grassland-forest have a better capacity to maintain the soil nutrients.展开更多
目的探讨高原地区患者术前凝血功能特征及血栓弹力图评估凝血功能的价值。方法将青海红十字医院2015年1月-2016年1月收治的择期手术患者60例纳入研究,根据高原居住时间不同将所有入组患者分为长期在高原居住的观察组(n=30)、初到高原的...目的探讨高原地区患者术前凝血功能特征及血栓弹力图评估凝血功能的价值。方法将青海红十字医院2015年1月-2016年1月收治的择期手术患者60例纳入研究,根据高原居住时间不同将所有入组患者分为长期在高原居住的观察组(n=30)、初到高原的对照组(n=30)。术前及术后3 h测定两组患者的凝血、血常规、血栓弹力图等指标,进一步分析血栓弹力图与凝血、血常规的相关性。结果观察组患者的术前及术后3 h的凝血酶原时间(PT)、活化部分凝血活酶时间(APTT)低于对照组,纤维蛋白原(FIB)、血小板(PLT)、血红蛋白(HGB)、红细胞比容(Hct)及红细胞(RBC)高于对照组(P<0.05);观察组患者的术前及术后3 h R值、CL30水平低于对照组,MA水平高于对照组(P<0.05);血栓弹力图中的R值、CL30与PT、APTT呈正相关,与FIB、PLT、HGB、Hct及RBC呈负相关(P<0.05),MA与PT、APTT呈负相关(P<0.05),与FIB、PLT、HGB、Hct、RBC呈正相关(P<0.05)。结论高原地区患者存在高凝状态,血栓弹力图可以直观评估患者的凝血功能及血常规状态,可用于临床凝血状态监测及早期采取干预措施,具有积极的临床意义。展开更多
Slope spectrum has been proved to be a significant methodology in revealing geomorphological features in the study of Chinese loess terrain. The determination of critical areas in deriving slope spectra is an indispen...Slope spectrum has been proved to be a significant methodology in revealing geomorphological features in the study of Chinese loess terrain. The determination of critical areas in deriving slope spectra is an indispensable task. Along with the increase in the size of the study area, the derived spectra are becoming more and more alike, such that their dif- ferences can be ignored in favor of a standard. Subsequently, the test size is defined as the Slope Spectrum Critical Area （SSCA）. SSCA is not only the foundation of the slope spectrum calculation but also, to some extent, a reflection of geomorphological development of loess relief. High resolution DEMs are important in extracting the slope spectrum. A set of 48 DEMs with different landform areas of the Loess Plateau in northern Shaanxi province was selected for the experiment. The spatial distribution of SSCA is investigated with a geo-statistical analysis method, resulting in values ranging from 6.18 km^2 to 35.1 km^2. Primary experimental results show that the spatial distribution of SSCA is correlated with the spatial distribution of the soil erosion intensity, to a certain extent reflecting the terrain complexity. The critical area of the slope spectrum presents a spatial variation trend of weak-strong-weak from north to south. Four terrain parameters, gully density, slope skewness, terrain driving force （Td） and slope of slope （SOS）, were chosen as indicators. There exists a good exponential function relationship between SSCA and gully density, terrain driving force （Td） and SOS and a loga- rithmic function relationship between SSCA and slope skewness. Slope skewness increases, and gully density, terrain driving force and SOS decrease with increasing SSCA. SSCA can be utilized as a discriminating factor to identify loess landforms, in that spatial distributions of SSCA and the evolution of loess landforms are correlative. Following the evolution of a loess landform from tableland to gully-hilly region, this also proves that SSCA can repre展开更多
文摘The irrational land use is one of the main reasons for the soil erosion and nutrient loss in the loess hilly area of China. In this project, 4 types of typical land use structure of sustain ment for about 15 years in the loess hill slope are selected to study the effect of land use structure on the distribution of soil nutrients. From hill bottom to hill top, the patterns of land use types are:, grassland-slope farmland-forest, slope farmland-grassland-forest, terrace-grassland-forest and slope farmland-forest-grassland. By measuring the contents of the total N, total P, available N, available P and organic matter of soils, the results show that the land use structure types of slope farmland-grassland-forest and terrace-grassland-forest have a better capacity to maintain the soil nutrients.
文摘目的探讨高原地区患者术前凝血功能特征及血栓弹力图评估凝血功能的价值。方法将青海红十字医院2015年1月-2016年1月收治的择期手术患者60例纳入研究,根据高原居住时间不同将所有入组患者分为长期在高原居住的观察组(n=30)、初到高原的对照组(n=30)。术前及术后3 h测定两组患者的凝血、血常规、血栓弹力图等指标,进一步分析血栓弹力图与凝血、血常规的相关性。结果观察组患者的术前及术后3 h的凝血酶原时间(PT)、活化部分凝血活酶时间(APTT)低于对照组,纤维蛋白原(FIB)、血小板(PLT)、血红蛋白(HGB)、红细胞比容(Hct)及红细胞(RBC)高于对照组(P<0.05);观察组患者的术前及术后3 h R值、CL30水平低于对照组,MA水平高于对照组(P<0.05);血栓弹力图中的R值、CL30与PT、APTT呈正相关,与FIB、PLT、HGB、Hct及RBC呈负相关(P<0.05),MA与PT、APTT呈负相关(P<0.05),与FIB、PLT、HGB、Hct、RBC呈正相关(P<0.05)。结论高原地区患者存在高凝状态,血栓弹力图可以直观评估患者的凝血功能及血常规状态,可用于临床凝血状态监测及早期采取干预措施,具有积极的临床意义。
基金Foundation： National Natural Science Foundation of China, No.41171299, No.41171320, No.41401237
文摘Slope spectrum has been proved to be a significant methodology in revealing geomorphological features in the study of Chinese loess terrain. The determination of critical areas in deriving slope spectra is an indispensable task. Along with the increase in the size of the study area, the derived spectra are becoming more and more alike, such that their dif- ferences can be ignored in favor of a standard. Subsequently, the test size is defined as the Slope Spectrum Critical Area （SSCA）. SSCA is not only the foundation of the slope spectrum calculation but also, to some extent, a reflection of geomorphological development of loess relief. High resolution DEMs are important in extracting the slope spectrum. A set of 48 DEMs with different landform areas of the Loess Plateau in northern Shaanxi province was selected for the experiment. The spatial distribution of SSCA is investigated with a geo-statistical analysis method, resulting in values ranging from 6.18 km^2 to 35.1 km^2. Primary experimental results show that the spatial distribution of SSCA is correlated with the spatial distribution of the soil erosion intensity, to a certain extent reflecting the terrain complexity. The critical area of the slope spectrum presents a spatial variation trend of weak-strong-weak from north to south. Four terrain parameters, gully density, slope skewness, terrain driving force （Td） and slope of slope （SOS）, were chosen as indicators. There exists a good exponential function relationship between SSCA and gully density, terrain driving force （Td） and SOS and a loga- rithmic function relationship between SSCA and slope skewness. Slope skewness increases, and gully density, terrain driving force and SOS decrease with increasing SSCA. SSCA can be utilized as a discriminating factor to identify loess landforms, in that spatial distributions of SSCA and the evolution of loess landforms are correlative. Following the evolution of a loess landform from tableland to gully-hilly region, this also proves that SSCA can repre
