Diffusion tensor imaging was performed in 105 volunteers free of central nervous system lesions.No differences were found in fractional anisotropy between the left and right cerebral peduncles among subjects（P 0.05）...Diffusion tensor imaging was performed in 105 volunteers free of central nervous system lesions.No differences were found in fractional anisotropy between the left and right cerebral peduncles among subjects（P 0.05）.The lower limit value of fractional anisotropy was 0.36,and the asymmetry ratio was 0.77.The area and lower limit value of the cerebral peduncles were 0.90 cm2 and 0.83,respectively.These results will be useful in evaluating the diagnosis of Wallerian degeneration following cerebral infarction.展开更多
草地叶面积指数(Leaf area index,LAI)是天然草地的重要结构参数,能够用来监测草地的生长状况和生产力水平,对草地资源可持续利用和科学管理具有重要意义。以内蒙古锡林郭勒盟典型草原为研究对象,首先使用无人机激光雷达(Airborne light...草地叶面积指数(Leaf area index,LAI)是天然草地的重要结构参数,能够用来监测草地的生长状况和生产力水平,对草地资源可持续利用和科学管理具有重要意义。以内蒙古锡林郭勒盟典型草原为研究对象,首先使用无人机激光雷达(Airborne light detection and ranging,Air-LiDAR)草地冠层观测数据,通过解析点云数据构建冠层高度模型(Canopy height model,CHM),随后进行研究区草地冠层间隙率计算,最后基于Beer-Lambert方法进行0.05 m、0.10 m、0.15 m、0.20 m 4个不同空间分辨率采样尺度下的LAI估算,并选择CHM低值、中值、高值3个不同子区域分别进行不同冠层高度下LAI的检验和分析。结果表明:(1)草地叶面积指数与冠层高度模型数值呈正相关、与冠层间隙率呈负相关。(2)机载LiDAR草地LAI估算的最优采样尺度为0.15 m,CHM不同高度子区域LAI结果检验R^(2)和RMSE分别为:低值区为0.66和0.04;中值区为0.54和0.34;高值区为0.54和1.17,表明无人机LiDAR可捕获草地冠层观测采样存在的异质性差异分布特征。(3)不同空间分辨率0.05~0.20 m间隔采样LAI结果表明,对于CHM低值、植被分布稀疏区域不同分辨率LAI无显著空间尺度变化差异,但CHM高值、较密植被分布群落LAI会随空间分辨率表现出尺度性差异。综上所述,本研究设计完成的无人机LiDAR草地LAI估算模型,参数机理具体、流程方法可操作性强,具有较好的数值检验精度,可为激光雷达在草地植被叶面积指数遥感反演及应用提供技术参考。展开更多
The Mazhuangshan area lies in northeast to Aqikekuduke, where are distributed intermediate\|acid rocks, which were formed in the Middle\|Late Carboniferous epoch. The magmatic rocks are peraluminous and belong to calc...The Mazhuangshan area lies in northeast to Aqikekuduke, where are distributed intermediate\|acid rocks, which were formed in the Middle\|Late Carboniferous epoch. The magmatic rocks are peraluminous and belong to calcareous series. All values of ACNK(1.03-\{2.12\}), ANK(1.67-2.93), SI(4.1-33), δ(0.71-4.82), La/ΣREE(0.09-0.26) ΣLREE/ΣHREE(1.76-11.01), (La/Sm)\-N(1.60-6.35), (Sm/Nd)\-N(0.33-0.58), (La/Yb)\-N(4.7-12.1), La\-N/Lu\-X(5.9-11.8), (Ce/Yb)\-N(3.14-6.64), δEu(0.38-\{1.06\}), Rb\-N/Sr\-N(42-120) and Sr\+*(0.02-0.2) demonstrate they vary with DI(\{45-90\}). S\|B diagram also shows that the lithophile elements are abundant in acidic magmatic rocks. Moreover, it is concluded that the primitive magma originated from a subduction zone at the continental edge, and underwent fractional crystallization and contamination, then generated the magmatic rocks. The multi\|cation index (R1: 3055-3993, R2: 286-438) shows that the primitive magma originated from the mantle. All these conclusions are beneficial for exploring gold deposits in the area.展开更多
This paper investigates the effect of launching multiple weapons against an area target of normally distributed elements. We provide an analytical form of the average damage fraction and then apply it to obtain optima...This paper investigates the effect of launching multiple weapons against an area target of normally distributed elements. We provide an analytical form of the average damage fraction and then apply it to obtain optimal aimpoints. To facilitate the computational efforts in practice, we also consider optimizations over given constrained patterns of aimpoints. Finally, we derive scaling laws for optimal aimpoints and optimal damage fraction with respect to the radius of the area target.展开更多
基金the grant of Science and Technology Bureau of Zhongshan, No. 20102C146
文摘Diffusion tensor imaging was performed in 105 volunteers free of central nervous system lesions.No differences were found in fractional anisotropy between the left and right cerebral peduncles among subjects（P 0.05）.The lower limit value of fractional anisotropy was 0.36,and the asymmetry ratio was 0.77.The area and lower limit value of the cerebral peduncles were 0.90 cm2 and 0.83,respectively.These results will be useful in evaluating the diagnosis of Wallerian degeneration following cerebral infarction.
文摘The Mazhuangshan area lies in northeast to Aqikekuduke, where are distributed intermediate\|acid rocks, which were formed in the Middle\|Late Carboniferous epoch. The magmatic rocks are peraluminous and belong to calcareous series. All values of ACNK(1.03-\{2.12\}), ANK(1.67-2.93), SI(4.1-33), δ(0.71-4.82), La/ΣREE(0.09-0.26) ΣLREE/ΣHREE(1.76-11.01), (La/Sm)\-N(1.60-6.35), (Sm/Nd)\-N(0.33-0.58), (La/Yb)\-N(4.7-12.1), La\-N/Lu\-X(5.9-11.8), (Ce/Yb)\-N(3.14-6.64), δEu(0.38-\{1.06\}), Rb\-N/Sr\-N(42-120) and Sr\+*(0.02-0.2) demonstrate they vary with DI(\{45-90\}). S\|B diagram also shows that the lithophile elements are abundant in acidic magmatic rocks. Moreover, it is concluded that the primitive magma originated from a subduction zone at the continental edge, and underwent fractional crystallization and contamination, then generated the magmatic rocks. The multi\|cation index (R1: 3055-3993, R2: 286-438) shows that the primitive magma originated from the mantle. All these conclusions are beneficial for exploring gold deposits in the area.
文摘This paper investigates the effect of launching multiple weapons against an area target of normally distributed elements. We provide an analytical form of the average damage fraction and then apply it to obtain optimal aimpoints. To facilitate the computational efforts in practice, we also consider optimizations over given constrained patterns of aimpoints. Finally, we derive scaling laws for optimal aimpoints and optimal damage fraction with respect to the radius of the area target.
