[目的]评价兰州市北山削山造地引起的土壤质量变化,旨在为该区削山造地工程和生态效益评价提供科学依据和建议。[方法]选择兰州市城关区北山原有耕地、林地、草地、削山产生的新造地4种土地利用方式,采集土壤物理性质、化学性质和根系...[目的]评价兰州市北山削山造地引起的土壤质量变化,旨在为该区削山造地工程和生态效益评价提供科学依据和建议。[方法]选择兰州市城关区北山原有耕地、林地、草地、削山产生的新造地4种土地利用方式,采集土壤物理性质、化学性质和根系生物量样品,基于主成分分析法(principal component analysis,PCA)筛选出最小数据集(minimum data set,MDS),通过土壤质量指数对兰州市北山土壤质量进行评价。[结果]①基于包括12项理化指标的土壤质量全数据集(total data set,TDS)的主成分分析,构建了由容重、速效磷、速效钾、全氮、pH值组成的最小数据集。②兰州市北山4种土地利用方式下土壤质量指数排序为:耕地>林地>新造地>草地,削山造地显著影响了土壤的水分保持、有机质积累、全氮、速效钾含量等。③最小数据集和全数据集之间相关性系数为0.66,最小数据集能够较好地进行土壤质量评价(p<0.01)。[结论]兰州市北山的耕地和林地具有更好的土壤质量,新造地土壤的持水与积累养分能力低于原有耕地和林地,是未来植被恢复和重建的重点区域。削山造地时应尽量安排在草地上进行,注意对原有耕地和林地的保护。展开更多
本文以内蒙古通辽市科尔沁左翼后旗巴胡塔镇乌旦塔拉村为试验区,选取13个土壤微形态指标,利用Photoshop、土壤切片图像处理分析系统、Image-pro plus 6.0软件对土壤微形态图像进行处理,采用定性、定量相结合的方法对不同改良处理后的砂...本文以内蒙古通辽市科尔沁左翼后旗巴胡塔镇乌旦塔拉村为试验区,选取13个土壤微形态指标,利用Photoshop、土壤切片图像处理分析系统、Image-pro plus 6.0软件对土壤微形态图像进行处理,采用定性、定量相结合的方法对不同改良处理后的砂质土壤肥力进行评价,在此基础上建立了砂质土壤肥力评价的微形态指标最小数据集(MDS)。得出以下结论:与对照组单元1相比,其他各个单元的土壤结构体、粗骨颗粒等微形态特征变化不显著。单元10(黏土、有机肥、腐殖酸施加量分别为3.00×10~5、3.00×10~4、7.50×10~3 kg/hm^2)中土壤黏粒最多、基质比最大、有机物质频率最高;土壤孔隙状况以及毛管孔隙发育最好的单元分别是单元8和单元13(黏土、有机肥、腐殖酸施加量分别是单元8:1.50×105、3.00×10~4、1.125×10~4 kg/hm^2,单元13:7.50×10~4、3.00×10~4、3.75×103 kg/hm^2)。准则层指标土壤基质、土壤孔隙、有机物质、土壤结构体、粗骨颗粒的权重分别为0.336、0.253、0.203、0.124、0.084。砂质土壤肥力评价的最小数据集包括基质比、基质类型、基质颜色、毛管孔隙占比、孔隙类型、有机物质类型、粗骨颗粒平均粒径7个指标,MDS评价结果与原始评价结果呈显著的线性相关关系,因此实际评价砂质土壤肥力时,可以MDS的7个微形态指标代替原始的13个指标。展开更多
Digestive endoscopy is currently the main diagnostic procedure for investigation of the digestive tract when a digestive disease is suspected.The use of computers and electronic medical records for the management of e...Digestive endoscopy is currently the main diagnostic procedure for investigation of the digestive tract when a digestive disease is suspected.The use of computers and electronic medical records for the management of endoscopic data are an important key to improving endoscopy unit efficiency and productivity.This technology supports optimal program operation,monitoring and evaluation colorectal cancer screening.This article is a comprehensive survey of endoscopic electronic medical records and information systems.Computerized clinical records have the capability of identifying patients due for screening and to calculate baseline rates of colorectal cancer screening by patient characteristics and by primary care physician and practice group.This paper describes data flow in the endoscopy unit,the minimum data set of colorectal cancer and key features of endoscopic electronic medical record.In addition,the researchers state standards in different aspects,especially terminology standards and interoperability standards for image and text.展开更多
文摘[目的]评价兰州市北山削山造地引起的土壤质量变化,旨在为该区削山造地工程和生态效益评价提供科学依据和建议。[方法]选择兰州市城关区北山原有耕地、林地、草地、削山产生的新造地4种土地利用方式,采集土壤物理性质、化学性质和根系生物量样品,基于主成分分析法(principal component analysis,PCA)筛选出最小数据集(minimum data set,MDS),通过土壤质量指数对兰州市北山土壤质量进行评价。[结果]①基于包括12项理化指标的土壤质量全数据集(total data set,TDS)的主成分分析,构建了由容重、速效磷、速效钾、全氮、pH值组成的最小数据集。②兰州市北山4种土地利用方式下土壤质量指数排序为:耕地>林地>新造地>草地,削山造地显著影响了土壤的水分保持、有机质积累、全氮、速效钾含量等。③最小数据集和全数据集之间相关性系数为0.66,最小数据集能够较好地进行土壤质量评价(p<0.01)。[结论]兰州市北山的耕地和林地具有更好的土壤质量,新造地土壤的持水与积累养分能力低于原有耕地和林地,是未来植被恢复和重建的重点区域。削山造地时应尽量安排在草地上进行,注意对原有耕地和林地的保护。
文摘Digestive endoscopy is currently the main diagnostic procedure for investigation of the digestive tract when a digestive disease is suspected.The use of computers and electronic medical records for the management of endoscopic data are an important key to improving endoscopy unit efficiency and productivity.This technology supports optimal program operation,monitoring and evaluation colorectal cancer screening.This article is a comprehensive survey of endoscopic electronic medical records and information systems.Computerized clinical records have the capability of identifying patients due for screening and to calculate baseline rates of colorectal cancer screening by patient characteristics and by primary care physician and practice group.This paper describes data flow in the endoscopy unit,the minimum data set of colorectal cancer and key features of endoscopic electronic medical record.In addition,the researchers state standards in different aspects,especially terminology standards and interoperability standards for image and text.