The Sluice Gate with Freight Carts is the earliest extant scroll in China that depicted a water mill.It was drawn during the early or middle Northern Song dynasty and was possibly a true portrayal of the West Water Mi...The Sluice Gate with Freight Carts is the earliest extant scroll in China that depicted a water mill.It was drawn during the early or middle Northern Song dynasty and was possibly a true portrayal of the West Water Mill Office.The copresence of a banquet scene of the Northern Song dynasty’s scholar-officials and a water mill both suggests a realistic reproduction of a specific scene and indicates the significance of the water mill as a cultural space.The Northern Song dynasty’s government-operated water mills were especially noticeable in the Capital Circuit京畿路,whose center was Dongjing东京.The basic development path of government-operated water mills in the inner and outer city of Dongjing was first from grain processing,which supplied the needs of the imperial palace,to tea processing,in which the governmental commercial capital also participated.Regarding city space and the use of water sources,the development spread from the north of the city to the south.Other prefectures outside Dongjing also had government-operated water mills—some brought income that could be used as official fiscal expenditure,including military expenditure,and were used to satisfy the need of local people’s livelihood,while some were used to serve the monopoly policy of tea and demonstrate the benevolent governance of local officials.In the Northern Song dynasty,the water mill was no longer merely a production site;rather,it was also a cultural space that integrated a natural background and artificial ingenuity.Closely related to the hosting of emperors and the garden making,sightseeing,feasting,and drinking of scholar-officials,along with the festival activities of locals,the water mill in the Northern Song dynasty was of great cultural significance.展开更多
为提高植被分类的精度,在利用高光谱图像提取植被信息时需要考虑训练样本和地形等其他因素的影响。以长白山为研究背景,基于CART(Classification And Regression Tree)算法构建决策树模型,对高光谱图像进行植被分类。由于混合像元的影响...为提高植被分类的精度,在利用高光谱图像提取植被信息时需要考虑训练样本和地形等其他因素的影响。以长白山为研究背景,基于CART(Classification And Regression Tree)算法构建决策树模型,对高光谱图像进行植被分类。由于混合像元的影响,以采用PPI(Pixel Purity Index)提取的纯净像元作为训练样本,提取植被指数、纹理和地形等分类特征变量。基于这些变量构建CART决策树对植被分类,并将结果与最大似然法分类结果进行比较。结果表明,CART决策树分类法可实现光谱、纹理和地形特征的有效组合,有较好的分类效果。展开更多
沙漠化是我国北方土地退化的主要形式之一,也是国内外研究中的重要环境问题。以民勤县为例,讨论了CART(Classification and Regression Tree)决策树在沙漠化研究中的应用,并使用Landsat8OLI遥感影像为数据源,构建了一种可行的用于研究...沙漠化是我国北方土地退化的主要形式之一,也是国内外研究中的重要环境问题。以民勤县为例,讨论了CART(Classification and Regression Tree)决策树在沙漠化研究中的应用,并使用Landsat8OLI遥感影像为数据源,构建了一种可行的用于研究区的沙漠化信息提取规则,进行地表沙漠化信息提取。结果表明:所构建的决策树模型结构简单,沙漠化提取效果较好;在研究区域达到87.70%的分类精度,Kappa系数为0.848 4,分类精度也较高。同时,归一化裸露指数(NDBI)和地表反照率(Albedo)是两个明显的沙漠化特征量,在沙漠化提取中起着重要作用。然而,CART决策树作为一种基于监督的分类方法,模型构建时,选择相对较高质量的训练样本和准确合理的输入端变量,可大大提高沙漠化信息的提取精度。展开更多
【目的】探讨牛卵泡颗粒细胞中可卡因-苯丙胺调节转录肽(cocaine-and amphetamine-regulated transcript,CART)的表达对牛不同阶段卵泡发育的影响。【方法】通过对牛卵泡转录组ODF1(the largest onset of deviation follicle)和ODF2(the...【目的】探讨牛卵泡颗粒细胞中可卡因-苯丙胺调节转录肽(cocaine-and amphetamine-regulated transcript,CART)的表达对牛不同阶段卵泡发育的影响。【方法】通过对牛卵泡转录组ODF1(the largest onset of deviation follicle)和ODF2(the second largest onset of deviation follicle)颗粒细胞(granulesa cells,GCs)构建RNA文库,Illumina Hi Seq 2000平台测序;采集屠宰牛双侧卵巢,通过黄体形态特征筛选处于第一卵泡波阶段的最大卵泡和第二大卵泡;分别抽取卵泡液,竞争性ELISA法测定卵泡液雌激素(estrodiol,E2)和孕酮(progestin,P)浓度,确定优势卵泡(dominant follicles,DF)和从属卵泡(subordinate follicles,SF);分别分离DF和SF颗粒细胞(granulosa cells,GCs),提取总RNA;设定3个重复样本,以RPLP0作为内参基因,设计引物在牛DF和SF进行q RT-PCR表达量检测,Graph Pad Prism 5.0作图并进行显著性分析;兔抗CART一抗检测CART在牛卵泡的表达。【结果】转录组测序结果显示,CART在ODF1的表达量是ODF2的38.2倍;通过黄体形态特征及激素测定共筛选出3头牛的卵泡发育处于第一卵泡波,并获得DF和SF;q RT-PCR结果显示CART在DF与SF的表达量差异极显著(P<0.01),高达2 310倍,与转录组测序结果的表达差异趋势一致;免疫组化结果表明,CART在牛DF和SF中均有表达,且DF表达量明显高于SF,同时,CART主要在卵泡颗粒细胞层表达。【结论】在牛卵泡发育过程中,卵泡发育选择期有其它抑制因子抑制了大多数卵泡的发育,阻止其成为DF;当出现偏差后,CART的高表达抑制了DF进入排卵期,推测CART可能是通过促进卵泡颗粒细胞的凋亡,进一步抑制了颗粒细胞层E2的分泌,最终导致DF闭锁。展开更多
文摘The Sluice Gate with Freight Carts is the earliest extant scroll in China that depicted a water mill.It was drawn during the early or middle Northern Song dynasty and was possibly a true portrayal of the West Water Mill Office.The copresence of a banquet scene of the Northern Song dynasty’s scholar-officials and a water mill both suggests a realistic reproduction of a specific scene and indicates the significance of the water mill as a cultural space.The Northern Song dynasty’s government-operated water mills were especially noticeable in the Capital Circuit京畿路,whose center was Dongjing东京.The basic development path of government-operated water mills in the inner and outer city of Dongjing was first from grain processing,which supplied the needs of the imperial palace,to tea processing,in which the governmental commercial capital also participated.Regarding city space and the use of water sources,the development spread from the north of the city to the south.Other prefectures outside Dongjing also had government-operated water mills—some brought income that could be used as official fiscal expenditure,including military expenditure,and were used to satisfy the need of local people’s livelihood,while some were used to serve the monopoly policy of tea and demonstrate the benevolent governance of local officials.In the Northern Song dynasty,the water mill was no longer merely a production site;rather,it was also a cultural space that integrated a natural background and artificial ingenuity.Closely related to the hosting of emperors and the garden making,sightseeing,feasting,and drinking of scholar-officials,along with the festival activities of locals,the water mill in the Northern Song dynasty was of great cultural significance.
文摘沙漠化是我国北方土地退化的主要形式之一,也是国内外研究中的重要环境问题。以民勤县为例,讨论了CART(Classification and Regression Tree)决策树在沙漠化研究中的应用,并使用Landsat8OLI遥感影像为数据源,构建了一种可行的用于研究区的沙漠化信息提取规则,进行地表沙漠化信息提取。结果表明:所构建的决策树模型结构简单,沙漠化提取效果较好;在研究区域达到87.70%的分类精度,Kappa系数为0.848 4,分类精度也较高。同时,归一化裸露指数(NDBI)和地表反照率(Albedo)是两个明显的沙漠化特征量,在沙漠化提取中起着重要作用。然而,CART决策树作为一种基于监督的分类方法,模型构建时,选择相对较高质量的训练样本和准确合理的输入端变量,可大大提高沙漠化信息的提取精度。
文摘【目的】探讨牛卵泡颗粒细胞中可卡因-苯丙胺调节转录肽(cocaine-and amphetamine-regulated transcript,CART)的表达对牛不同阶段卵泡发育的影响。【方法】通过对牛卵泡转录组ODF1(the largest onset of deviation follicle)和ODF2(the second largest onset of deviation follicle)颗粒细胞(granulesa cells,GCs)构建RNA文库,Illumina Hi Seq 2000平台测序;采集屠宰牛双侧卵巢,通过黄体形态特征筛选处于第一卵泡波阶段的最大卵泡和第二大卵泡;分别抽取卵泡液,竞争性ELISA法测定卵泡液雌激素(estrodiol,E2)和孕酮(progestin,P)浓度,确定优势卵泡(dominant follicles,DF)和从属卵泡(subordinate follicles,SF);分别分离DF和SF颗粒细胞(granulosa cells,GCs),提取总RNA;设定3个重复样本,以RPLP0作为内参基因,设计引物在牛DF和SF进行q RT-PCR表达量检测,Graph Pad Prism 5.0作图并进行显著性分析;兔抗CART一抗检测CART在牛卵泡的表达。【结果】转录组测序结果显示,CART在ODF1的表达量是ODF2的38.2倍;通过黄体形态特征及激素测定共筛选出3头牛的卵泡发育处于第一卵泡波,并获得DF和SF;q RT-PCR结果显示CART在DF与SF的表达量差异极显著(P<0.01),高达2 310倍,与转录组测序结果的表达差异趋势一致;免疫组化结果表明,CART在牛DF和SF中均有表达,且DF表达量明显高于SF,同时,CART主要在卵泡颗粒细胞层表达。【结论】在牛卵泡发育过程中,卵泡发育选择期有其它抑制因子抑制了大多数卵泡的发育,阻止其成为DF;当出现偏差后,CART的高表达抑制了DF进入排卵期,推测CART可能是通过促进卵泡颗粒细胞的凋亡,进一步抑制了颗粒细胞层E2的分泌,最终导致DF闭锁。
