利用ASTER数据,基于The Environment for Visualizing Images(ENVI)ZOOM软件平台,采用面向对象的多尺度影像分割技术与规则创建相结合方法,提取了珠峰保护区核心区的灌丛植被类型。在对影像进行去阴影处理和各种辅助信息融合的基础上,使...利用ASTER数据,基于The Environment for Visualizing Images(ENVI)ZOOM软件平台,采用面向对象的多尺度影像分割技术与规则创建相结合方法,提取了珠峰保护区核心区的灌丛植被类型。在对影像进行去阴影处理和各种辅助信息融合的基础上,使用Feature Extraction模块对影像进行分割,基于分割对象的高程、NDVI、纹理和光谱信息创建了适合研究区的灌丛提取规则。研究表明:该分类方法不仅能够克服传统基于像元分类方法中的"椒盐效应"问题,而且能够综合利用辅助信息(DEM、NDVI等)和地物本身的信息(光谱特征、纹理特征等),有效提高解译精度。以已有数据对分类结果进行了检验,分类精度达84.7%,分类结果较理想。展开更多
江西南昌西汉海昏侯墓是近年来汉代考古的重要发现,其出土的大量珍贵文物为研究西汉列侯葬制、复原汉代社会生活提供了难能可贵的实物资料。其中墓园M1和M5棺内各出土了玻璃席,作为玉敛葬中的一种葬具,是西汉手工业水平的重要见证,也是...江西南昌西汉海昏侯墓是近年来汉代考古的重要发现,其出土的大量珍贵文物为研究西汉列侯葬制、复原汉代社会生活提供了难能可贵的实物资料。其中墓园M1和M5棺内各出土了玻璃席,作为玉敛葬中的一种葬具,是西汉手工业水平的重要见证,也是列侯丧葬等级和汉代法赙制度的具体表征。本研究使用傅里叶变换显微红外光谱(micro-FTIR)、热裂解气相色谱-质谱分析(Py-GC/MS)以及基于质谱的动物考古学技术(zooarchaeology by mass spectrometry,ZooMS)等多种手段,对海昏侯墓出土玻璃席包边及疑似胶结材料进行了科学分析。首先利用傅里叶变换显微红外光谱确定样品中均含有蛋白质成分,再利用热裂解气相色谱质谱技术检测包边残留物和疑似胶结材料的主要成分,判断包边样品应为动物性来源,最后使用基于质谱的动物考古学技术,确定了M1刘贺墓玻璃席包边残留物的生物来源为普通牛,推测包边残留物材料为牛皮。包边样品中检测到的少量酚类物质,表明牛皮在鞣制过程中可能使用了植物鞣剂。样品中含量较高的脂肪酸类物质可能来源于皮革鞣制中的加脂处理。此外,两件胶结材料样品中含有吲哚类、脯氨酸类化合物以及磷酸三甲脂,但未发现胆固醇类化合物,判断胶结材料应为蛋清。本研究明确了玻璃席包边制作材料,为了解古代制席工艺、制作技法提供了科学认知,两张玻璃席制作精美、工艺复杂,展现了西汉中期高超的制席工艺,为后续针对玻璃席开展的保护修复工作提供了重要参考依据。展开更多
To address the limitations of existing coupling methods in aero-engine system simulation,which fail to adaptively adjust iterative parameters and coupling relationships,which can result in low efficiency and in⁃stabil...To address the limitations of existing coupling methods in aero-engine system simulation,which fail to adaptively adjust iterative parameters and coupling relationships,which can result in low efficiency and in⁃stability,this study introduces a‘Dynamic Event-Driven Co-Simulation’algorithm integrated with decision tree algorithms.This algorithm separates the overall coupling relationships and the main solver from the primary mod⁃el,utilizing a dynamic event monitoring module to adaptively adjust simulation strategies,including iteration pa⁃rameters,coupling relationships,and convergence criteria.This facilitates efficient adaptive simulations of dy⁃namic events while balancing solution accuracy and computational efficiency.The research focuses on a twinshaft turbofan engine,establishing six system-level models that encompass overall performance and various sub⁃systems based on three coupling methods,along with a multidisciplinary multi-fidelity simulation framework in⁃corporating a 3D CFD nozzle model.The study tests both model exchange and coupled simulation methods under a 14 s transient acceleration and deceleration scenario.In a 100%throttle condition,a high-fidelity nozzle model is used to analyze the sensitivity of different convergence criteria on computational efficiency and accuracy.Re⁃sults indicate that the accuracy and efficiency achieved with this method are comparable to those of PROOSIS soft⁃ware(18 s and 35 s,respectively),while being 71%more efficient than Simulink software(62 s and 120 s,re⁃spectively).Furthermore,appropriately relaxing the convergence criteria for the 0D model(from 10-6 to 10-4)while enhancing those for the 3D model(from 3000 steps to 6000 steps)can effectively balance computational accuracy and efficiency.展开更多
文摘江西南昌西汉海昏侯墓是近年来汉代考古的重要发现,其出土的大量珍贵文物为研究西汉列侯葬制、复原汉代社会生活提供了难能可贵的实物资料。其中墓园M1和M5棺内各出土了玻璃席,作为玉敛葬中的一种葬具,是西汉手工业水平的重要见证,也是列侯丧葬等级和汉代法赙制度的具体表征。本研究使用傅里叶变换显微红外光谱(micro-FTIR)、热裂解气相色谱-质谱分析(Py-GC/MS)以及基于质谱的动物考古学技术(zooarchaeology by mass spectrometry,ZooMS)等多种手段,对海昏侯墓出土玻璃席包边及疑似胶结材料进行了科学分析。首先利用傅里叶变换显微红外光谱确定样品中均含有蛋白质成分,再利用热裂解气相色谱质谱技术检测包边残留物和疑似胶结材料的主要成分,判断包边样品应为动物性来源,最后使用基于质谱的动物考古学技术,确定了M1刘贺墓玻璃席包边残留物的生物来源为普通牛,推测包边残留物材料为牛皮。包边样品中检测到的少量酚类物质,表明牛皮在鞣制过程中可能使用了植物鞣剂。样品中含量较高的脂肪酸类物质可能来源于皮革鞣制中的加脂处理。此外,两件胶结材料样品中含有吲哚类、脯氨酸类化合物以及磷酸三甲脂,但未发现胆固醇类化合物,判断胶结材料应为蛋清。本研究明确了玻璃席包边制作材料,为了解古代制席工艺、制作技法提供了科学认知,两张玻璃席制作精美、工艺复杂,展现了西汉中期高超的制席工艺,为后续针对玻璃席开展的保护修复工作提供了重要参考依据。
文摘To address the limitations of existing coupling methods in aero-engine system simulation,which fail to adaptively adjust iterative parameters and coupling relationships,which can result in low efficiency and in⁃stability,this study introduces a‘Dynamic Event-Driven Co-Simulation’algorithm integrated with decision tree algorithms.This algorithm separates the overall coupling relationships and the main solver from the primary mod⁃el,utilizing a dynamic event monitoring module to adaptively adjust simulation strategies,including iteration pa⁃rameters,coupling relationships,and convergence criteria.This facilitates efficient adaptive simulations of dy⁃namic events while balancing solution accuracy and computational efficiency.The research focuses on a twinshaft turbofan engine,establishing six system-level models that encompass overall performance and various sub⁃systems based on three coupling methods,along with a multidisciplinary multi-fidelity simulation framework in⁃corporating a 3D CFD nozzle model.The study tests both model exchange and coupled simulation methods under a 14 s transient acceleration and deceleration scenario.In a 100%throttle condition,a high-fidelity nozzle model is used to analyze the sensitivity of different convergence criteria on computational efficiency and accuracy.Re⁃sults indicate that the accuracy and efficiency achieved with this method are comparable to those of PROOSIS soft⁃ware(18 s and 35 s,respectively),while being 71%more efficient than Simulink software(62 s and 120 s,re⁃spectively).Furthermore,appropriately relaxing the convergence criteria for the 0D model(from 10-6 to 10-4)while enhancing those for the 3D model(from 3000 steps to 6000 steps)can effectively balance computational accuracy and efficiency.
