The current urban green space construction was guided by a two-dimensional index evaluation system, resulting in weak ecological benefits of green space. Green plot ratio (GPR), as a three-dimensional indicator, can c...The current urban green space construction was guided by a two-dimensional index evaluation system, resulting in weak ecological benefits of green space. Green plot ratio (GPR), as a three-dimensional indicator, can characterize the ecological benefits of green areas and the ability of green areas to participate in the operation and regulation of urban ecosystems. As an important component of urban green space, the GPR index was added to the two-dimensional index evaluation system to optimize the green space, which can promote the development of low-carbon, healthy and ecological green space. Based on the research of 22 residential districts in the central city of Chongqing, the Leaf area index (LAI) index of common native garden plants in Chongqing was formed to improve the accuracy of green capacity index measurement in Chongqing. The study also took the residential community of Sunrise City in Banan District of Chongqing as an example, and carried out the optimization design practice from four types of residential community green areas: green areas next to houses, road green areas, concentrated green areas, and green areas attached to public service facilities.展开更多
建立一种采用液相色谱法同时测定亚麻荠植株中8种酚酸和黄酮化合物含量的方法,并探讨亚麻荠植株醇提物的体外抗氧化活性。试验确定采用体积分数75%乙醇回流提取样品,选用Angilent Eclipse XDB plus C_(18)柱为色谱柱。结果表明:8种化合...建立一种采用液相色谱法同时测定亚麻荠植株中8种酚酸和黄酮化合物含量的方法,并探讨亚麻荠植株醇提物的体外抗氧化活性。试验确定采用体积分数75%乙醇回流提取样品,选用Angilent Eclipse XDB plus C_(18)柱为色谱柱。结果表明:8种化合物的标准曲线回归方程线性关系良好,相关系数均大于0.999;8种化合物的加标回收率为95.26%~102.61%,建立的方法可以对不同产地的亚麻荠植株样品进行区分。抗氧化试验表明,亚麻荠植株醇提取物对羟基自由基与DPPH自由基具有较好的清除能力。展开更多
株高和叶面积指数(Leaf Area Index,LAI)反映着作物的生长发育状况。为了探究基于无人机可见光遥感提取冬小麦株高的可靠性,以及利用株高和可见光植被指数估算LAI的精度,本文获取了拔节期、抽穗期、灌浆期的无人机影像,提取了冬小麦株...株高和叶面积指数(Leaf Area Index,LAI)反映着作物的生长发育状况。为了探究基于无人机可见光遥感提取冬小麦株高的可靠性,以及利用株高和可见光植被指数估算LAI的精度,本文获取了拔节期、抽穗期、灌浆期的无人机影像,提取了冬小麦株高与可见光植被指数,使用逐步回归、偏最小二乘、随机森林、人工神经网络四种方法建立LAI估测模型,并对株高提取及LAI估测情况进行精度评价。结果显示:(1)株高提取值Hc与实测值Hd高度拟合(R^(2)=0.894,RMSE=6.695,NRMSE=9.63%),株高提取效果好;(2)与仅用可见光植被指数相比,基于株高与可见光植被指数构建的LAI估测模型精度更高,且随机森林为最优建模方法,当其决策树个数为50时模型估测效果最好(R^(2)=0.809,RMSE=0.497,NRMSE=13.85%,RPD=2.336)。利用无人机可见光遥感方法,高效、准确、无损地实现冬小麦株高及LAI提取估测可行性较高,该研究结果可为农情遥感监测提供参考。展开更多
夏直播棉花能够在较短生育期内获得与常规模式相当的产量,但其产量高效形成的机理及其与冠层微环境的关系仍不清楚。因此,本试验采用完全随机区组设计,设置6个种植密度(7.50株m^(–2)、8.25株m^(–2)、9.00株m^(–2)、9.75株m^(–2)、10...夏直播棉花能够在较短生育期内获得与常规模式相当的产量,但其产量高效形成的机理及其与冠层微环境的关系仍不清楚。因此,本试验采用完全随机区组设计,设置6个种植密度(7.50株m^(–2)、8.25株m^(–2)、9.00株m^(–2)、9.75株m^(–2)、10.50株m^(–2)和11.25株m^(–2)),于2022-2023年在湖北武汉进行了大田试验。采用温湿度仪记录从现蕾到拔杆期间冠层温度和湿度,冠层分析仪测定结铃期冠层不同高度光辐射强度,手工收获计产。结果表明,棉花产量随种植密度增加先升后降,其中9.75株m^(–2)最高(籽棉3246.5 kg hm^(–2)、皮棉1203.2 kg hm^(–2)), 2年平均较7.50株m^(–2)提高(15.0%和17.8%)。冠层日均温、最高温、最低温随种植密度增加而降低,而冠层相对湿度、最高湿度、最低湿度随种植密度增加而增加。冠层透光率,水平方向呈“V”型分布,棉行中间最大;垂直方向中下部(离地10^50cm)随种植密度增加而减小,上部(离地50^70cm)随种植密度增加而增大。群体叶面积指数随种植密度增加先升后降,其中9.75株m^(–2)最高,2年平均为2.6。相关分析表明,棉花产量随冠层日均温和最高温升高而降低,随冠层相对湿度和最高湿度增加而增加;随冠层中下部透光率增大而减小,随上部透光率增加而增大。综上,棉花夏直播种植模式,适当增加种植密度(9.75^11.25株m^(–2))有利于提高单位面积成铃数,改善冠层微环境,如冠层透光率70cm处85%以上,50 cm处37%^40%,30 cm处14%^16%,10 cm处9%以下,冠层温度26.5^27.0℃,冠层湿度74%^77%,从而提高棉花产量。展开更多
文摘The current urban green space construction was guided by a two-dimensional index evaluation system, resulting in weak ecological benefits of green space. Green plot ratio (GPR), as a three-dimensional indicator, can characterize the ecological benefits of green areas and the ability of green areas to participate in the operation and regulation of urban ecosystems. As an important component of urban green space, the GPR index was added to the two-dimensional index evaluation system to optimize the green space, which can promote the development of low-carbon, healthy and ecological green space. Based on the research of 22 residential districts in the central city of Chongqing, the Leaf area index (LAI) index of common native garden plants in Chongqing was formed to improve the accuracy of green capacity index measurement in Chongqing. The study also took the residential community of Sunrise City in Banan District of Chongqing as an example, and carried out the optimization design practice from four types of residential community green areas: green areas next to houses, road green areas, concentrated green areas, and green areas attached to public service facilities.
文摘建立一种采用液相色谱法同时测定亚麻荠植株中8种酚酸和黄酮化合物含量的方法,并探讨亚麻荠植株醇提物的体外抗氧化活性。试验确定采用体积分数75%乙醇回流提取样品,选用Angilent Eclipse XDB plus C_(18)柱为色谱柱。结果表明:8种化合物的标准曲线回归方程线性关系良好,相关系数均大于0.999;8种化合物的加标回收率为95.26%~102.61%,建立的方法可以对不同产地的亚麻荠植株样品进行区分。抗氧化试验表明,亚麻荠植株醇提取物对羟基自由基与DPPH自由基具有较好的清除能力。
文摘株高和叶面积指数(Leaf Area Index,LAI)反映着作物的生长发育状况。为了探究基于无人机可见光遥感提取冬小麦株高的可靠性,以及利用株高和可见光植被指数估算LAI的精度,本文获取了拔节期、抽穗期、灌浆期的无人机影像,提取了冬小麦株高与可见光植被指数,使用逐步回归、偏最小二乘、随机森林、人工神经网络四种方法建立LAI估测模型,并对株高提取及LAI估测情况进行精度评价。结果显示:(1)株高提取值Hc与实测值Hd高度拟合(R^(2)=0.894,RMSE=6.695,NRMSE=9.63%),株高提取效果好;(2)与仅用可见光植被指数相比,基于株高与可见光植被指数构建的LAI估测模型精度更高,且随机森林为最优建模方法,当其决策树个数为50时模型估测效果最好(R^(2)=0.809,RMSE=0.497,NRMSE=13.85%,RPD=2.336)。利用无人机可见光遥感方法,高效、准确、无损地实现冬小麦株高及LAI提取估测可行性较高,该研究结果可为农情遥感监测提供参考。
文摘夏直播棉花能够在较短生育期内获得与常规模式相当的产量,但其产量高效形成的机理及其与冠层微环境的关系仍不清楚。因此,本试验采用完全随机区组设计,设置6个种植密度(7.50株m^(–2)、8.25株m^(–2)、9.00株m^(–2)、9.75株m^(–2)、10.50株m^(–2)和11.25株m^(–2)),于2022-2023年在湖北武汉进行了大田试验。采用温湿度仪记录从现蕾到拔杆期间冠层温度和湿度,冠层分析仪测定结铃期冠层不同高度光辐射强度,手工收获计产。结果表明,棉花产量随种植密度增加先升后降,其中9.75株m^(–2)最高(籽棉3246.5 kg hm^(–2)、皮棉1203.2 kg hm^(–2)), 2年平均较7.50株m^(–2)提高(15.0%和17.8%)。冠层日均温、最高温、最低温随种植密度增加而降低,而冠层相对湿度、最高湿度、最低湿度随种植密度增加而增加。冠层透光率,水平方向呈“V”型分布,棉行中间最大;垂直方向中下部(离地10^50cm)随种植密度增加而减小,上部(离地50^70cm)随种植密度增加而增大。群体叶面积指数随种植密度增加先升后降,其中9.75株m^(–2)最高,2年平均为2.6。相关分析表明,棉花产量随冠层日均温和最高温升高而降低,随冠层相对湿度和最高湿度增加而增加;随冠层中下部透光率增大而减小,随上部透光率增加而增大。综上,棉花夏直播种植模式,适当增加种植密度(9.75^11.25株m^(–2))有利于提高单位面积成铃数,改善冠层微环境,如冠层透光率70cm处85%以上,50 cm处37%^40%,30 cm处14%^16%,10 cm处9%以下,冠层温度26.5^27.0℃,冠层湿度74%^77%,从而提高棉花产量。
