坛紫菜耐低盐品系的选育与特性分析

本实验室采用人工诱变技术获得一个坛紫菜耐低盐品系(YZ-7),为了验证该品系的耐低盐性状能否遗传,本文对其壳孢子和F1叶状体的低盐耐受性分别进行了测试,并以坛紫菜野生品系(WT)作为对照,结果表明:在不同盐度下培养2周的YZ-7和WT的壳孢子,在26盐度组存活率无显著差异;在15盐度组,YZ-7的壳孢子存活率和假根发生率分别比WT提高了34%和35%;在8和5盐度组,YZ-7的壳孢子存活率、分裂率及假根发生率分别比WT提高了65%、32%和62%,以及137%、80%和154%;在3盐度组,YZ-7的壳孢子存活率和分裂率分别比WT提高了458%和171%,其中约44.9%的YZ-7壳孢子萌发体能形成假根,而WT的壳孢子萌发体基本上不长假根。在26盐度中培养35d后的F1叶状体再分别在26、15、8、5和3盐度下培养30d,YZ-7叶状体的特定生长率分别为WT的1.7、1.9、1.5、1.6和1.6倍,绝对生长率分别是WT的3.4、4.1、1.8、2.0和1.6倍。此外,YZ-7叶状体的叶绿素荧光活性(PSⅡ最大光量子产量、实际光量子产量)及三种主要光合色素(叶绿素a、藻红蛋白和藻蓝蛋白)的含量也明显高于WT。上述结果证实,坛紫菜选育品系YZ-7是一个耐低盐且生长快的优良品系,其优良性状可稳定传递给下一代,有望被培育成适宜栽培的新品种。     

天宫一号高光谱数据辐射校正的CUDA并行优化

高光谱图像经过辐射校正后,消除了探测元的响应差异,能更好地满足专题信息提取的数据要求.利用探测元的列均值、列标准差等统计信息对天宫一号高光谱短波红外数据进行辐射校正检验,并基于GPU CUDA计算模型对均值归一化、矩匹配、相邻列均衡等3种相对辐射校正算法进行了并行计算优化.通过辐射校正计算流程拆分,CPU控制流程逻辑,GPU执行数据级并行计算,并建立CUDA的计算单元与数据单元的映射关系,获得5—7倍的计算加速比,这些辐射校正算法依据图像自身统计信息,且易于进行并行计算优化,满足实时校正的处理时效要求,为未来高光谱数据在轨实时辐射校正提供了新思路.     

面向对象规则和支持向量机的天宫一号高光谱影像分类

传统的高光谱分类方法通常基于单一像元的光谱或纹理特征,很少考虑地物空间结构信息与空间相关特征.本文将面向对象规则与基于像元的分类进行融合,利用对象的空间结构特征和光谱特征进行混合分类,旨在克服像元层次分类的不足.本文尝试性的提出了两种混合分类方法:(1)基于分形网络演化的多尺度分割支持向量机分类(2)基于多层分水岭分割的SVM分类,并将这两种方法应用到天宫一号高光谱数据上.结果表明:基于面向对象规则的混合分类方法有效地提高了分类精度,不仅能够改善同谱异物现象,而且解决分类结果中地物破碎的问题.     

天宫一号超光谱仪红外谱段的实验室定标

天宫一号超光谱仪红外谱段光谱范围是8.0—10.5 μm,采用红外线列焦平面推扫方式成像.通过实验室定标实验,获得了每个探测元对应的辐射响应系数和响应线性度,并得到每一探测元的动态范围与噪声等效温差,验证了图像输出校正效果,同时,根据定标实验误差来源分析计算了最终的辐射定标误差.     

基于ICESat-2 ATLAS数据的DEM高程精度评价

为探究ASTER GDEMV3、SRTM1 DEM和AW3D30 DEM 3种开源DEM数据的高程精度,本文以高精度ICESat-2 ATLAS测高数据为参考数据,利用GIS统计分析、误差相关分析及数理统计对DEM的高程精度进行对比评价。结果表明：①AW3D30的质量最稳定;SRTM1 DEM在平原精度最高;在高原山地精度由高到低依次为AW3D30 DEM、ASTER GDEMV3、SRTM1 DEM。②DEM数据高程精度受地表覆盖影响较大,且与地形因素密切相关,在相同地表覆盖的两个研究区中DEM数据高程精度表现情况不一致,SRTM在平原地表覆盖下精度表现最好,平均误差为3.15 m,AW3D30 DEM在山地地表覆盖下精度表现最好,平均误差为7.61 m。③坡度对DEM数据的高程精度影响较大,在两个研究区3种DEM数据的高程误差均随坡度的增加而增加;坡向对DEM数据的高程精度影响较小,未发现明显的规律。     

基于嫦娥二号微波辐射计数据月球中低纬度亮温异常区地质分析研究

月球表面的微波辐射亮度温度与月表地质结构和月表物质的物理化学特性相关。为了对月球亮温分布异常区域进行地质分析,文章首先计算嫦娥亮温数据的时角,采用克里金插值的方法得到了不同频率不同时刻中低纬度的微波亮温图。结合奇异值分解(SVD)模型分析了月表亮温变化异常,结果表明风暴洋位置和靠近月海东北部的高地区域等存在亮温变化异常,月海区域(除风暴洋外)为3 GHz和37 GHz两个场的总体相关区域。通过对月球火山分布地区的区域亮温变化进行分析,发现这热异常可能是由于月球火山活动造成的。     

Scales and causes of heterogeneity in bars in a large multi‐channel river: Río Paraná, Argentina

To date, published studies of alluvial bar architecture in large rivers have been restricted mostly to case studies of individual bars and single locations. Relatively little is known about how the depositional processes and sedimentary architecture of kilometre‐scale bars vary within a multi‐kilometre reach or over several hundreds of kilometres downstream. This study presents Ground Penetrating Radar and core data from 11, kilometre‐scale bars from the Río Paraná, Argentina. The investigated bars are located between 30 km upstream and 540 km downstream of the Río Paraná – Río Paraguay confluence, where a significant volume of fine‐grained suspended sediment is introduced into the network. Bar‐scale cross‐stratified sets, with lengths and widths up to 600 m and thicknesses up to 12 m, enable the distinction of large river deposits from stacked deposits of smaller rivers, but are only present in half the surface area of the bars. Up to 90% of bar‐scale sets are found on top of finer‐grained ripple‐laminated bar‐trough deposits. Bar‐scale sets make up as much as 58% of the volume of the deposits in small, incipient mid‐channel bars, but this proportion decreases significantly with increasing age and size of the bars. Contrary to what might be expected, a significant proportion of the sedimentary structures found in the Río Paraná is similar in scale to those found in much smaller rivers. In other words, large river deposits are not always characterized by big structures that allow a simple interpretation of river scale. However, the large scale of the depositional units in big rivers causes small‐scale structures, such as ripple sets, to be grouped into thicker cosets, which indicate river scale even when no obvious large‐scale sets are present. The results also show that the composition of bars differs between the studied reaches upstream and downstream of the confluence with the Río Paraguay. Relative to other controls on downstream fining, the tributary input of fine‐grained suspended material from the Río Paraguay causes a marked change in the composition of the bar deposits. Compared to the upstream reaches, the sedimentary architecture of the downstream reaches in the top ca 5 m of mid‐channel bars shows: (i) an increase in the abundance and thickness (up to metre‐scale) of laterally extensive (hundreds of metres) fine‐grained layers; (ii) an increase in the percentage of deposits comprised of ripple sets (to >40% in the upper bar deposits); and (iii) an increase in bar‐trough deposits and a corresponding decrease in bar‐scale cross‐strata (<10%). The thalweg deposits of the Río Paraná are composed of dune sets, even directly downstream from the Río Paraguay where the upper channel deposits are dominantly fine‐grained. Thus, the change in sedimentary facies due to a tributary point‐source of fine‐grained sediment is primarily expressed in the composition of the upper bar deposits.     

Variation of the 0+ ion density during low and high solar activity as measured by the SR0SS-C2 satellite

The O⁺ ion density measured by the SROSS-C2 satellite during solar minima (year 1995, F_10.7 = 77) and maxima (year 2000, F_10.7 = 181) has been analyzed for studying diurnal, seasonal, latitudinal and geomagnetic variations. The study region covers an area encompassed between 5-3 5° N latitude and 65-95° E longitude over India at a ~500 km altitude (F2 region). The year 2000 shows significant enhancement in the annual average of O⁺ ion density and attainment of post sunset secondary enhancement compared to 1995. Attributed to photoionization, daytime shows a maximum ionization compared to nighttime. However, attainment of post sunset secondary maxima is attributed to the strong pre-reversal enhancement in the vertical E x B drift. The effect of geomagnetic activity Kp through the E x B drift dynamic movement on O⁺ ion density distribution studies indicates periodicities of seven and nine days in 1995 and 2000, respectively, and polynomial dependency of the O⁺ ion density on geomagnetic activity Kp. Further on, stratification of the O⁺ ion density according to latitude (5-35° N) indicates high density in mid-latitudes (12-24° N) compared to high and low latitudes, except in the winter of 1995, which shows a distinct trend (i.e., density decreases with increasing latitude).     

新疆库车盆地钾盐科探1井含盐系地球化学特征及找钾指示

在盐湖沉积演化过程中,钾盐矿物在盐类沉积的中晚期阶段才开始析出。因此,研究含盐系盐类的沉积地球化学特征,不仅可以从侧面获取岩盐的沉积物源和成盐古卤水蒸发浓缩程度等地球化学信息,而且更能揭示古盐湖钾盐富集趋势。文章通过对库车盆地钾盐科探1井钻取的岩芯样品进行高精度采样测试,得出岩盐中Mg×103/Cl、K×103/Cl、Li×103/Cl与K+、Mg2+、Li+、Ca2+、Cl-含量的垂向变化规律。并与库车盆地其他钻孔中的岩盐含钾性进行对比,同时,依据钻井剖面岩性特征,与潜江凹陷和大汶口凹陷含盐系剖面进行对比,论述研究区成盐的地球化学特征,对其钾盐成矿前景进行分析和评价。     

暴雨内涝情景下城市消防服务可达性的精细化评估

为了揭示城市暴雨内涝灾害对应急响应服务功能的影响,论文基于高精度城市洪涝模型(FloodMap)和增强型两步移动搜寻法(E2SFCA),对暴雨内涝灾害影响下上海市中心城区消防服务可达性进行精细化评估。研究结果表明：① 百年一遇暴雨内涝情景下,内涝最严重时积水深度超过50 cm的淹没范围整体呈现“西高东低”分布态势,淹没总面积约1.5 km²,可导致471条路段(约占路网全长5.11%)通行受阻。② 上海市中心城区消防服务可达性的空间差异比较显著,大体呈现出由黄浦江两岸向西北和东南方向递减态势,但在一天中的不同时段,可达性空间格局变化并不明显。③ 与正常天气条件相比,暴雨内涝情景下不可达单元(250 m×250 m)数量显著增多,夜间低峰、早高峰、白天平峰和晚高峰时段分别增加36.32%、35.89%、39.07%和32.01%;从暴雨内涝的过程(全程120 min)上看,在雨峰后半段((30, 45] min)不可达单元数量最多,消防服务可达性的空间差异程度最大。④ 消防服务可达性表现出一定程度的空间集聚特征,其中高值聚集区(“高—高”型)主要位于黄浦江两岸以及浦西边缘地区,低值聚集区(“低—低”型)主要位于西北和西南区域,这2类聚集区呈“团块状”分布,而“高—低”型和“低—高”型集聚均不显著。⑤ 研究区内消防服务可达性与需求的空间失配现象(“低需求—高可达”或“高需求—低可达”)较为明显,而暴雨内涝会加剧空间失配问题。研究结果可为提升城市洪涝灾害管理与应急响应服务的精细化水平提供科学依据。