This work builds an isobaric steady-state fluid analytical-physical model of the plasma conduction region in a conical target. The hydrodynamic instability in the double-cone ignition scheme^([21]) for inertial confin...This work builds an isobaric steady-state fluid analytical-physical model of the plasma conduction region in a conical target. The hydrodynamic instability in the double-cone ignition scheme^([21]) for inertial confinement fusion(ICF) proposed by Zhang is studied with the built model. With this idealized model, the relevant parameters, such as density, temperature,and length of the plasma in the conduction region of the conical target under long-pulse conditions are given. The solution of the proposed analytical model dovetails with the trend of the numerical simulation. The model and results in this paper are beneficial for discussing how to attenuate Rayleigh-Taylor instability in ICF processes with conical and spherical targets.展开更多
Land use regionalization is a strategic measure for the rational use,management and protection of land resources based on local conditions.Based on the needs of targeted poverty alleviation and rural revitalization st...Land use regionalization is a strategic measure for the rational use,management and protection of land resources based on local conditions.Based on the needs of targeted poverty alleviation and rural revitalization strategy and the analysis on the natural and socioeconomic conditions,characteristics of land resources,and the current status of land use in Luquan County,corresponding regionalization indices were selected from four aspects:economic environment conditions,socioeconomic conditions,land resources and land use structure,and poverty alleviation and development level,a scientific and feasible index system for land use regionalization was constructed,and land use in Luquan County was regionalized by using systematic cluster analysis method.The results show that the 16 townships(towns)of Luquan County were divided into four land use regions,poverty alleviation region for development of new town and characteristic industries in the southwest(I),agricultural development and ecological poverty alleviation region in central mountainous area(II),poverty alleviation region for development of characteristic agriculture and tourism towns in eastern plateau mountainous area(III),and poverty alleviation region for development of characteristic industries and protection of land economy in the northern alpine valley area(IV).In addition,suggestions were put forward for the rational use of land in each region.展开更多
In order to explore the differences of projects on linking newly-added cropland quotas with the amount of land used for construction in targeted poverty alleviation in different rural areas,this paper selects the soci...In order to explore the differences of projects on linking newly-added cropland quotas with the amount of land used for construction in targeted poverty alleviation in different rural areas,this paper selects the social,economic,cultural and ecological evaluation indexes,and introduces the AHP method,to measure the benefits before and after the implementation of the four typical projects on linking newly-added cropland quotas with the amount of land used for construction in Xinjiang. The results show that after the implementation of the project,the social,economic,cultural,ecological and comprehensive benefits of each region have been improved,but the benefits of regions with different economic levels are significantly different. This paper holds that the projects on linking newly-added cropland quotas with the amount of land used for construction in different regions should be considered from the ultimate goal before the establishment and implementation of the project,so as to realize the win-win situation between the urban-rural requisition-compensation balance and the targeted poverty alleviation in rural areas.展开更多
Poverty alleviation requires knowledge support. Targeted poverty alleviation, aiming to tackle rural poverty, needs to be supported by corresponding rural human resource development. Currently, China's human resou...Poverty alleviation requires knowledge support. Targeted poverty alleviation, aiming to tackle rural poverty, needs to be supported by corresponding rural human resource development. Currently, China's human resource development in impoverished rural regions is faced with some major problems; a huge population distributed over a vast area, a lack of technological and cultural attainment, obsolete concepts, obsolete technical resources, and a significant gap between rural and urban education attainment. Rural human resource development, which is geared to targeted poverty alleviation, includes a variety of impoverished rural population-oriented trainings, such as intelligence development, skills training, modern professionalism &work attitude cultivation, physical & mental health education, as well as modern lifestyle & civilized manners guidance. Targeted poverty alleviation should be equipped with mechanisms of comprehensive layout & planning, coordinated advancement of development content and implementation, and a mechanism of organization & input. The approaches to the advancement of rural human resource development are enhancing basic education, building a system of vocational education and training, raising the social security level and improving the supporting mechanisms.展开更多
针对现有三维目标检测算法对存在遮挡及距离较远目标检测效果差的问题,以基于点云的三维目标检测算法(3D object proposal generation and detection from point cloud,PointRCNN)为基础,对网络进行改进,提高三维目标检测精度。对区域...针对现有三维目标检测算法对存在遮挡及距离较远目标检测效果差的问题,以基于点云的三维目标检测算法(3D object proposal generation and detection from point cloud,PointRCNN)为基础,对网络进行改进,提高三维目标检测精度。对区域生成网络(region proposal network,RPN)获取的提议区域(region of interest,ROI)体素化处理,同时构建不同尺度的区域金字塔来捕获更加广泛的兴趣点;加入点云Transformer模块来增强对网格中心点局部特征的学习;在网络中加入球查询半径预测模块,使得模型可以根据点云密度自适应调整球查询的范围。最后,对所提算法的有效性进行了试验验证,在KITTI数据集下对模型的性能进行评估测试,同时设计相应的消融试验验证模型中各模块的有效性。展开更多
基于区域气候模式RegCM4对4个全球气候模式的动力降尺度模拟数据及未来人口预估数据,预估了SSP2-RCP4.5情景下全球升温1.5℃和2℃时,中国群发性高温事件(cluster high temperature events,CHTE)和CHTE人口暴露度的变化。结果表明:1.5℃...基于区域气候模式RegCM4对4个全球气候模式的动力降尺度模拟数据及未来人口预估数据,预估了SSP2-RCP4.5情景下全球升温1.5℃和2℃时,中国群发性高温事件(cluster high temperature events,CHTE)和CHTE人口暴露度的变化。结果表明:1.5℃和2℃升温阈值下,多模式集合(MME)预估CHTE年均频次相对于基准期分别增加31%和44%。不同强度事件中,严重CHTE事件的频次在1.5℃和2℃升温阈值下可分别增加约4.2倍和6.8倍。事件强度、持续时间、频次等指标趋向高值的发生概率更大。相对于2℃,1.5℃温升阈值下CHTE年均频次、持续时间和累计强度在全国大范围呈降低趋势,且表现出明显的区域性差异,年均频次的降幅自北到南递增,新疆和长江以南地区持续时间年均减少6 d以上(全国平均降幅为0.2 d),我国中东部地区累计强度年均减少20℃以上、新疆东部减少50℃以上(全国平均降幅为0.6℃)。此外,在1.5℃和2℃升温阈值下,MME预估CHTE影响人口的变化均呈现南增北减的空间分布,内蒙古地区略有减少,中东部地区普遍增加,全国总影响人口分别增加1.4倍和1.8倍。高温事件对城市的影响人口增幅更大(分别增加2.9倍和3.8倍),尤其是京津冀、长三角、珠三角、中原地区增幅最明显。全国的CHTE强度暴露度(分别增加2.2倍和5.2倍)和综合暴露度(分别增加1.2倍和1.8倍)呈明显增加趋势,特别是2℃升温阈值下城市的CHTE强度暴露度和综合暴露度的增幅分别高达10倍和4倍。展开更多
针对小目标水漂垃圾形态多变、分辨率低且信息有限,导致检测效果不理想的问题,提出一种改进的Faster-RCNN(Faster Regions with Convolutional Neural Network)水漂垃圾检测算法MP-Faster-RCNN(Faster-RCNN with Multi-scale feature an...针对小目标水漂垃圾形态多变、分辨率低且信息有限,导致检测效果不理想的问题,提出一种改进的Faster-RCNN(Faster Regions with Convolutional Neural Network)水漂垃圾检测算法MP-Faster-RCNN(Faster-RCNN with Multi-scale feature and Polarized self-attention)。首先,建立黄河兰州段小目标水漂垃圾数据集,将空洞卷积结合ResNet-50代替原来的VGG-16(Visual Geometry Group 16)作为主干特征提取网络,扩大感受野以提取更多小目标特征;其次,在区域生成网络(RPN)利用多尺度特征,设置3×3和1×1的两层卷积,补偿单一滑动窗口造成的特征丢失;最后,在RPN前加入极化自注意力,进一步利用多尺度和通道特征提取更细粒度的多尺度空间信息和通道间依赖关系,生成具有全局特征的特征图,实现更精确的目标框定位。实验结果表明,MP-Faster-RCNN能有效提高水漂垃圾检测精度,与原始Faster-RCNN相比,平均精度均值(mAP)提高了6.37个百分点,模型大小从521 MB降到了108 MB,且在同一训练批次下收敛更快。展开更多
散射中心是描述雷达目标高频散射机理的重要特征,准确提取雷达目标散射中心参数对解析雷达目标有着极其重要的研究意义。为了提高散射中心参数计算速度,通常将整幅合成孔径雷达(synthetic aperture radar,SAR)图像分解为多个包含散射中...散射中心是描述雷达目标高频散射机理的重要特征,准确提取雷达目标散射中心参数对解析雷达目标有着极其重要的研究意义。为了提高散射中心参数计算速度,通常将整幅合成孔径雷达(synthetic aperture radar,SAR)图像分解为多个包含散射中心的小区域,对每个小区域分别进行特征提取和参数计算。根据雷达目标散射中心的特点,提出了一种基于局部密度聚类的雷达目标散射中心区域分割技术。首先,对雷达图像进行Frost滤波、基于水平集方法(level set method,LSM)的图像分割和面积滤波的一系列图像预处理获得目标感兴趣(region of interest,ROI)区域,然后对预处理后的图像利用局部密度聚类算法检测散射中心并进行区域分割。实验中,采用模拟数据和真实数据对所提方法和传统图像分割算法展开数值实验,实验结果验证了所提方法在雷达目标散射中心区域分割的有效性和优越性。展开更多
基金Project supported by the Strategic Priority Research Program of Chinese Academy of Sciences (Grant Nos. XDA 25051000 and XDA 25010100)。
文摘This work builds an isobaric steady-state fluid analytical-physical model of the plasma conduction region in a conical target. The hydrodynamic instability in the double-cone ignition scheme^([21]) for inertial confinement fusion(ICF) proposed by Zhang is studied with the built model. With this idealized model, the relevant parameters, such as density, temperature,and length of the plasma in the conduction region of the conical target under long-pulse conditions are given. The solution of the proposed analytical model dovetails with the trend of the numerical simulation. The model and results in this paper are beneficial for discussing how to attenuate Rayleigh-Taylor instability in ICF processes with conical and spherical targets.
文摘Land use regionalization is a strategic measure for the rational use,management and protection of land resources based on local conditions.Based on the needs of targeted poverty alleviation and rural revitalization strategy and the analysis on the natural and socioeconomic conditions,characteristics of land resources,and the current status of land use in Luquan County,corresponding regionalization indices were selected from four aspects:economic environment conditions,socioeconomic conditions,land resources and land use structure,and poverty alleviation and development level,a scientific and feasible index system for land use regionalization was constructed,and land use in Luquan County was regionalized by using systematic cluster analysis method.The results show that the 16 townships(towns)of Luquan County were divided into four land use regions,poverty alleviation region for development of new town and characteristic industries in the southwest(I),agricultural development and ecological poverty alleviation region in central mountainous area(II),poverty alleviation region for development of characteristic agriculture and tourism towns in eastern plateau mountainous area(III),and poverty alleviation region for development of characteristic industries and protection of land economy in the northern alpine valley area(IV).In addition,suggestions were put forward for the rational use of land in each region.
基金Supported by Project of Hubei Provincial Department of Education(17Y034)
文摘In order to explore the differences of projects on linking newly-added cropland quotas with the amount of land used for construction in targeted poverty alleviation in different rural areas,this paper selects the social,economic,cultural and ecological evaluation indexes,and introduces the AHP method,to measure the benefits before and after the implementation of the four typical projects on linking newly-added cropland quotas with the amount of land used for construction in Xinjiang. The results show that after the implementation of the project,the social,economic,cultural,ecological and comprehensive benefits of each region have been improved,but the benefits of regions with different economic levels are significantly different. This paper holds that the projects on linking newly-added cropland quotas with the amount of land used for construction in different regions should be considered from the ultimate goal before the establishment and implementation of the project,so as to realize the win-win situation between the urban-rural requisition-compensation balance and the targeted poverty alleviation in rural areas.
基金a staged research result of"Outstanding Young Talent Development Program of Hunan Normal University"[140621]--a key program of 2016 Ministry of Education[DJA160266]under the 13th Five-Year Plan of National Education Science
文摘Poverty alleviation requires knowledge support. Targeted poverty alleviation, aiming to tackle rural poverty, needs to be supported by corresponding rural human resource development. Currently, China's human resource development in impoverished rural regions is faced with some major problems; a huge population distributed over a vast area, a lack of technological and cultural attainment, obsolete concepts, obsolete technical resources, and a significant gap between rural and urban education attainment. Rural human resource development, which is geared to targeted poverty alleviation, includes a variety of impoverished rural population-oriented trainings, such as intelligence development, skills training, modern professionalism &work attitude cultivation, physical & mental health education, as well as modern lifestyle & civilized manners guidance. Targeted poverty alleviation should be equipped with mechanisms of comprehensive layout & planning, coordinated advancement of development content and implementation, and a mechanism of organization & input. The approaches to the advancement of rural human resource development are enhancing basic education, building a system of vocational education and training, raising the social security level and improving the supporting mechanisms.
文摘针对现有三维目标检测算法对存在遮挡及距离较远目标检测效果差的问题,以基于点云的三维目标检测算法(3D object proposal generation and detection from point cloud,PointRCNN)为基础,对网络进行改进,提高三维目标检测精度。对区域生成网络(region proposal network,RPN)获取的提议区域(region of interest,ROI)体素化处理,同时构建不同尺度的区域金字塔来捕获更加广泛的兴趣点;加入点云Transformer模块来增强对网格中心点局部特征的学习;在网络中加入球查询半径预测模块,使得模型可以根据点云密度自适应调整球查询的范围。最后,对所提算法的有效性进行了试验验证,在KITTI数据集下对模型的性能进行评估测试,同时设计相应的消融试验验证模型中各模块的有效性。
文摘基于区域气候模式RegCM4对4个全球气候模式的动力降尺度模拟数据及未来人口预估数据,预估了SSP2-RCP4.5情景下全球升温1.5℃和2℃时,中国群发性高温事件(cluster high temperature events,CHTE)和CHTE人口暴露度的变化。结果表明:1.5℃和2℃升温阈值下,多模式集合(MME)预估CHTE年均频次相对于基准期分别增加31%和44%。不同强度事件中,严重CHTE事件的频次在1.5℃和2℃升温阈值下可分别增加约4.2倍和6.8倍。事件强度、持续时间、频次等指标趋向高值的发生概率更大。相对于2℃,1.5℃温升阈值下CHTE年均频次、持续时间和累计强度在全国大范围呈降低趋势,且表现出明显的区域性差异,年均频次的降幅自北到南递增,新疆和长江以南地区持续时间年均减少6 d以上(全国平均降幅为0.2 d),我国中东部地区累计强度年均减少20℃以上、新疆东部减少50℃以上(全国平均降幅为0.6℃)。此外,在1.5℃和2℃升温阈值下,MME预估CHTE影响人口的变化均呈现南增北减的空间分布,内蒙古地区略有减少,中东部地区普遍增加,全国总影响人口分别增加1.4倍和1.8倍。高温事件对城市的影响人口增幅更大(分别增加2.9倍和3.8倍),尤其是京津冀、长三角、珠三角、中原地区增幅最明显。全国的CHTE强度暴露度(分别增加2.2倍和5.2倍)和综合暴露度(分别增加1.2倍和1.8倍)呈明显增加趋势,特别是2℃升温阈值下城市的CHTE强度暴露度和综合暴露度的增幅分别高达10倍和4倍。
文摘针对小目标水漂垃圾形态多变、分辨率低且信息有限,导致检测效果不理想的问题,提出一种改进的Faster-RCNN(Faster Regions with Convolutional Neural Network)水漂垃圾检测算法MP-Faster-RCNN(Faster-RCNN with Multi-scale feature and Polarized self-attention)。首先,建立黄河兰州段小目标水漂垃圾数据集,将空洞卷积结合ResNet-50代替原来的VGG-16(Visual Geometry Group 16)作为主干特征提取网络,扩大感受野以提取更多小目标特征;其次,在区域生成网络(RPN)利用多尺度特征,设置3×3和1×1的两层卷积,补偿单一滑动窗口造成的特征丢失;最后,在RPN前加入极化自注意力,进一步利用多尺度和通道特征提取更细粒度的多尺度空间信息和通道间依赖关系,生成具有全局特征的特征图,实现更精确的目标框定位。实验结果表明,MP-Faster-RCNN能有效提高水漂垃圾检测精度,与原始Faster-RCNN相比,平均精度均值(mAP)提高了6.37个百分点,模型大小从521 MB降到了108 MB,且在同一训练批次下收敛更快。
文摘散射中心是描述雷达目标高频散射机理的重要特征,准确提取雷达目标散射中心参数对解析雷达目标有着极其重要的研究意义。为了提高散射中心参数计算速度,通常将整幅合成孔径雷达(synthetic aperture radar,SAR)图像分解为多个包含散射中心的小区域,对每个小区域分别进行特征提取和参数计算。根据雷达目标散射中心的特点,提出了一种基于局部密度聚类的雷达目标散射中心区域分割技术。首先,对雷达图像进行Frost滤波、基于水平集方法(level set method,LSM)的图像分割和面积滤波的一系列图像预处理获得目标感兴趣(region of interest,ROI)区域,然后对预处理后的图像利用局部密度聚类算法检测散射中心并进行区域分割。实验中,采用模拟数据和真实数据对所提方法和传统图像分割算法展开数值实验,实验结果验证了所提方法在雷达目标散射中心区域分割的有效性和优越性。
