As an important part of gas hydrates, light hydrocarbons （LHs）, especially C5 to C7 hydrocarbons with various monomer compounds, provide a wide variety of geological and geochemical information, which have received ...As an important part of gas hydrates, light hydrocarbons （LHs）, especially C5 to C7 hydrocarbons with various monomer compounds, provide a wide variety of geological and geochemical information, which have received much attention from organic geochemists and petroleum geologists.展开更多
The Tibetan Plateau(TP)is undergoing rapid urbanization.To improve urban sustainability and construct eco-logical security barriers,it is essential to quantify the spatial patterns of urbanization level on the TP,but ...The Tibetan Plateau(TP)is undergoing rapid urbanization.To improve urban sustainability and construct eco-logical security barriers,it is essential to quantify the spatial patterns of urbanization level on the TP,but the existing studies on the topic have been limited by the lack of socioeconomic data.This study aims to quantify the urbanization level on the TP in 2018 with Luojia1-01(LJ1-01)high-resolution nighttime light(NTL)data.Specifically,the compounded night light index is used to quantify spatial patterns of urbanization level at mul-tiple scales.The results showed that the TP had a low overall urbanization level with a large internal difference.The urbanization level in the northeast,southeast and south of the TP was relatively high,forming three hotspots centered in Xining City,Lhasa City and Shangri-La City,while the urbanization level in the central and western regions was relatively low.The analysis of influencing factors,based on the random forest model,showed that transportation and topography were the main factors affecting the TP’s spatial patterns of urbanization level.The comparison analysis with socioeconomic statistics and traditional NTL data showed that LJ1-01 NTL data can be used to more effectively quantify the urbanization level since it is more advantageous for reflecting the spatial extent of urban land and describing the spatial structure of socioeconomic activities within urban areas.These advantages are attributed to the high spatial resolution of the data,appropriate imaging time and unaf-fected by saturation phenomena.Thus,the proposed LJ1-01 NTL-based urbanization level measurement method has the potential for wide applications around the world,especially in less-developed regions lacking statistical data.Using this method,we refined the measurement of the TP’s urbanization level in 2018 for multiple scales including the region,basin,prefecture and county levels,which provides basic information for the further urban sustainability research on the TP.展开更多
Modern industry in northeast China started from light industry. From the end of 19th century to 1931 was the phase of initial development of light industry in northeast China. During this period, the development of li...Modern industry in northeast China started from light industry. From the end of 19th century to 1931 was the phase of initial development of light industry in northeast China. During this period, the development of light industry gave priority to grain processing industry. After occupying northeast China, Japanese vigorously developed heavy industry to meet the needs of munitions and paid more attention to raw materials and semi-finished articles industry for the purpose of the war. Light industry was impeded and developed slowly. After the founding of New China, large-scale economic construction took place in northeast and heavy industry received prior investment and equipment. Northeast region became the first heavy industry base through several five-year plans, the development of light industry made giant strides. The present features of light industry distribution are: difference of light industry distribution, similarity of light industry structure, and imbalance of light industry development.展开更多
This paper reports that the doped bi-layer organic light-emitting devices are fabricated by doping in different regions of the light-emitting layer, the admittance and luminance spectra to characterize the capacitance...This paper reports that the doped bi-layer organic light-emitting devices are fabricated by doping in different regions of the light-emitting layer, the admittance and luminance spectra to characterize the capacitance and luminance of the device are measured. Negative capacitance （NC） appeared at low frequencies when the doped devices are biased with high voltages. The measured phase difference between AC voltage applied across the device and AC current flowing through the device show that the device is inductive when NC appears.展开更多
为了克服基于单一视差合成的光场图像编码方法在遮挡区域无法恢复纹理细节的问题,提出一种基于多特征融合和几何感知网络的光场图像编码方法,以进一步提升遮挡场景下光场图像的压缩性能.首先,对密集光场稀疏采样,使用通用视频编码器(ver...为了克服基于单一视差合成的光场图像编码方法在遮挡区域无法恢复纹理细节的问题,提出一种基于多特征融合和几何感知网络的光场图像编码方法,以进一步提升遮挡场景下光场图像的压缩性能.首先,对密集光场稀疏采样,使用通用视频编码器(versatile video coding,VVC)对稀疏光场进行压缩;然后,在解码端使用2个关键分支模块,即视差估计模块和空间角度联合卷积模块,以获取光场图像全局的几何信息,确保在密集纹理和遮挡区域能够更充分地恢复特征;最后,为了挖掘2个分支融合特征的结构信息,构建了双向视图的堆栈结构,并运用几何感知的细化网络以重建高质量的密集光场.实验结果表明,与已有国际上流行的光场图像编码方法相比,所提出的方法具有显著优势.展开更多
[目的]提高近红外光谱技术在线检测柚子糖度的精度。[方法]采用自主研发的柚子在线无损检测设备采集3种光照区域的柚子的漫透射光谱数据,在650~950 nm的波长范围内采用标准正交变量变换(SNV)、多元散射校正(MSC)、归一化(normalize)、S...[目的]提高近红外光谱技术在线检测柚子糖度的精度。[方法]采用自主研发的柚子在线无损检测设备采集3种光照区域的柚子的漫透射光谱数据,在650~950 nm的波长范围内采用标准正交变量变换(SNV)、多元散射校正(MSC)、归一化(normalize)、SG一阶求导(savitzky-golay first order derivative,SG-1st)对原始数据进行预处理,使用自适应性加权算法(CARS)筛选反映柚子糖度的光谱特征,建立了偏最小二乘回归(PLSR)模型。使用未参与到建模的30个柚子样本进行在线验证。[结果]光照区域C结合SNV-CARS-PLSR方法的建模效果最优。其预测集的决定系数为0.95,均方根误差为0.30°Brix。在线验证时决定系数为0.90,均方根误差为0.58°Brix。模型对于柚子糖度具有较强的在线检测能力。[结论]在光斑直径为70 mm且位于柚子赤道上方20 mm的光照区域C的条件下采集的柚子光谱数据所建立的预测模型能更有效地实现柚子糖度的在线预测。展开更多
针对雾霾天气下交通信号灯定位准确率较低、图像增强时出现图像亮度不均匀的问题,该文提出一种基于改进的带色彩恢复的多尺度视网膜增强(Multi-Scale Retinex with Color Restoration,MSRCR)的雾霾天气下信号灯识别算法。首先利用改进的...针对雾霾天气下交通信号灯定位准确率较低、图像增强时出现图像亮度不均匀的问题,该文提出一种基于改进的带色彩恢复的多尺度视网膜增强(Multi-Scale Retinex with Color Restoration,MSRCR)的雾霾天气下信号灯识别算法。首先利用改进的MSRCR算法对有雾图像进行预处理,校正图像亮度并丰富图像细节;再利用最大稳定极值区域(Maximally Stable Extremal Regions,MSER)算法以及信号灯的背板信息确定信号灯的位置;最后将定位区域转换至HSV空间进行信号灯识别。结果表明,该方法能够在雾霾条件下有效地定位及识别交通信号灯。展开更多
基金financially supported by the National Natural Science Foundation of China(grant No.41273066)
文摘As an important part of gas hydrates, light hydrocarbons （LHs）, especially C5 to C7 hydrocarbons with various monomer compounds, provide a wide variety of geological and geochemical information, which have received much attention from organic geochemists and petroleum geologists.
基金the Second Tibetan Plateau Scientific Expedition and Research Program(Grant No.2019QZKK0405)the National Natural Science Foundation of China(Grant No.41871185&41971270)。
文摘The Tibetan Plateau(TP)is undergoing rapid urbanization.To improve urban sustainability and construct eco-logical security barriers,it is essential to quantify the spatial patterns of urbanization level on the TP,but the existing studies on the topic have been limited by the lack of socioeconomic data.This study aims to quantify the urbanization level on the TP in 2018 with Luojia1-01(LJ1-01)high-resolution nighttime light(NTL)data.Specifically,the compounded night light index is used to quantify spatial patterns of urbanization level at mul-tiple scales.The results showed that the TP had a low overall urbanization level with a large internal difference.The urbanization level in the northeast,southeast and south of the TP was relatively high,forming three hotspots centered in Xining City,Lhasa City and Shangri-La City,while the urbanization level in the central and western regions was relatively low.The analysis of influencing factors,based on the random forest model,showed that transportation and topography were the main factors affecting the TP’s spatial patterns of urbanization level.The comparison analysis with socioeconomic statistics and traditional NTL data showed that LJ1-01 NTL data can be used to more effectively quantify the urbanization level since it is more advantageous for reflecting the spatial extent of urban land and describing the spatial structure of socioeconomic activities within urban areas.These advantages are attributed to the high spatial resolution of the data,appropriate imaging time and unaf-fected by saturation phenomena.Thus,the proposed LJ1-01 NTL-based urbanization level measurement method has the potential for wide applications around the world,especially in less-developed regions lacking statistical data.Using this method,we refined the measurement of the TP’s urbanization level in 2018 for multiple scales including the region,basin,prefecture and county levels,which provides basic information for the further urban sustainability research on the TP.
文摘Modern industry in northeast China started from light industry. From the end of 19th century to 1931 was the phase of initial development of light industry in northeast China. During this period, the development of light industry gave priority to grain processing industry. After occupying northeast China, Japanese vigorously developed heavy industry to meet the needs of munitions and paid more attention to raw materials and semi-finished articles industry for the purpose of the war. Light industry was impeded and developed slowly. After the founding of New China, large-scale economic construction took place in northeast and heavy industry received prior investment and equipment. Northeast region became the first heavy industry base through several five-year plans, the development of light industry made giant strides. The present features of light industry distribution are: difference of light industry distribution, similarity of light industry structure, and imbalance of light industry development.
基金supported by the Natural Science Foundation of the Shanghai Committee of Science and Technology,China (GrantNo. 08JC1402300)
文摘This paper reports that the doped bi-layer organic light-emitting devices are fabricated by doping in different regions of the light-emitting layer, the admittance and luminance spectra to characterize the capacitance and luminance of the device are measured. Negative capacitance （NC） appeared at low frequencies when the doped devices are biased with high voltages. The measured phase difference between AC voltage applied across the device and AC current flowing through the device show that the device is inductive when NC appears.
文摘为了克服基于单一视差合成的光场图像编码方法在遮挡区域无法恢复纹理细节的问题,提出一种基于多特征融合和几何感知网络的光场图像编码方法,以进一步提升遮挡场景下光场图像的压缩性能.首先,对密集光场稀疏采样,使用通用视频编码器(versatile video coding,VVC)对稀疏光场进行压缩;然后,在解码端使用2个关键分支模块,即视差估计模块和空间角度联合卷积模块,以获取光场图像全局的几何信息,确保在密集纹理和遮挡区域能够更充分地恢复特征;最后,为了挖掘2个分支融合特征的结构信息,构建了双向视图的堆栈结构,并运用几何感知的细化网络以重建高质量的密集光场.实验结果表明,与已有国际上流行的光场图像编码方法相比,所提出的方法具有显著优势.
文摘[目的]提高近红外光谱技术在线检测柚子糖度的精度。[方法]采用自主研发的柚子在线无损检测设备采集3种光照区域的柚子的漫透射光谱数据,在650~950 nm的波长范围内采用标准正交变量变换(SNV)、多元散射校正(MSC)、归一化(normalize)、SG一阶求导(savitzky-golay first order derivative,SG-1st)对原始数据进行预处理,使用自适应性加权算法(CARS)筛选反映柚子糖度的光谱特征,建立了偏最小二乘回归(PLSR)模型。使用未参与到建模的30个柚子样本进行在线验证。[结果]光照区域C结合SNV-CARS-PLSR方法的建模效果最优。其预测集的决定系数为0.95,均方根误差为0.30°Brix。在线验证时决定系数为0.90,均方根误差为0.58°Brix。模型对于柚子糖度具有较强的在线检测能力。[结论]在光斑直径为70 mm且位于柚子赤道上方20 mm的光照区域C的条件下采集的柚子光谱数据所建立的预测模型能更有效地实现柚子糖度的在线预测。
文摘针对雾霾天气下交通信号灯定位准确率较低、图像增强时出现图像亮度不均匀的问题,该文提出一种基于改进的带色彩恢复的多尺度视网膜增强(Multi-Scale Retinex with Color Restoration,MSRCR)的雾霾天气下信号灯识别算法。首先利用改进的MSRCR算法对有雾图像进行预处理,校正图像亮度并丰富图像细节;再利用最大稳定极值区域(Maximally Stable Extremal Regions,MSER)算法以及信号灯的背板信息确定信号灯的位置;最后将定位区域转换至HSV空间进行信号灯识别。结果表明,该方法能够在雾霾条件下有效地定位及识别交通信号灯。
