中国西南纵向岭谷区孢粉空间组合对阻隔作用的指示意义

35 surface soil samples and 28 profile soil samples were collected in Longitudinal Range-Gorge Region, Southwest China. The distribution of pollen and spores and their relationship with the environment are analyzed. The results show that there are significant differences in pollen and spores taxa, amounts, dominant taxa and florae between the eastern and western flanks of the Ailao Mountain. There are more pollen and spores taxa, a greater amount and complexity on the western flank of the mountain than those on the eastern flank, while the dominant taxa are more centralized and prominent on the eastern flank of the Ailao Mountain. As for the plant florae distribution, there are significant differences in the number of taxa and composition between the eastern and the western flanks. The analysis of profile pollen and spores assemblage shows that its trends of variation are basically in accordance with the surface pollen and spores, which are also indicators of the environmental differences between the two flanks of the mountain. These significant spatial differences of pollen and spores are very close to the regional topography and climate difference. The mountain running perpendicular to the moisture-laden air flow serves as a barrier and the monsoon circulations the east and the west of the mountain result in different energy-moisture characteristics. We conclude that the main patterns of the pollen and spores can be attributed to the environmental differences.     

基于RV指数的道路网络干扰效应空间分异研究——以云南省纵向岭谷区为例

不同尺度下道路网络干扰效应空间分布差异研究及其驱动因子识别,对进一步研究道路网络引起的生态系统演变具有重要意义.利用表示道路网络干扰效应的RV(Roadless Volume)指数.以云南省纵向岭谷区为案例区.在不同尺度上分析了道路网络干扰效应的空间分布差异.结果表明,云南省纵向岭谷区道路网络干扰效应总体呈现中部高、两边低的趋势:地州及县域尺度上,干扰效应主要集中在昆瑞公路沿线的地州及县市;流域内部分区尺度上,各个流域的中下游地区干扰效应较强;流域尺度上,红河流域相比其他流域干扰效应强.进一步的相关性分析表明,道路网络干扰效应受生态承载力、道路密度和海拔高度等因素的驱动.     

Time constraints for the evolution of a large slope collapse in karstified mountainous terrain of the southwestern Crimean Mountains, Ukraine

Prominent longitudinal features are often reported on the surfaces of mass movement deposits. However, the genesis and implications of these have not hitherto been considered, and herein we present preliminary observations of their occurrence both in the field and in the laboratory. Elongated ridges are often oriented (sub-) parallel to the flow direction and aligned radially from the source due to debris spreading. They are particularly prominent in large (> 10⁶m³) rock avalanches emplaced onto deformable substrates and are also found in the proximal reaches of volcanic debris avalanches. Flowbands, which are longer and thinner expressions of longitudinal ridges, are continuous along the entire flow length and are observed in rock avalanches emplaced onto glaciers, in snow and some ice avalanches, in pyroclastic flows and some block-and-ash flows, in ejecta sheets, in extraterrestrial landslides, and in some volcanic debris avalanches. Other volcanic debris avalanches and the distal areas of rock avalanches often display hummocks that are aligned radially from the source; we propose that these aligned hummocks are remnants of longitudinal ridges. The formation of elongate ridges (and their expressions as flowbands, aligned hummocks, or distal lobes and digits) in qualitatively-similar fashion in both laboratory and field environments suggests they represent an intrinsic tendency of granular flows in a wide range of situations.     

基于形变观测分析中国台湾东部花东纵谷断层运动特征

花东纵谷断层是中国台湾动力作用和地壳运动变形最强烈的断层之一,其断层运动特征和强震危险程度一直备受学者的关注。文中分别以同震地表位移、1992-1999年震间形变数据为约束,反演2003年成功MW 6.8地震同震位错分布和花东纵谷断层震间运动特征。结果表明：花东纵谷断层北段处于强闭锁状态（闭锁率高达0.9）,闭锁深度深（约27 km）;南段闭锁程度较弱（闭锁率约0.5）,闭锁深度较浅（约12 km）;中段闭锁程度与闭锁深度介于南北段之间。另一方面,2003年成功MW 6.8地震微观震中位于震间无震滑移区与闭锁区的过渡带附近。依据同震位错、震间断层运动反演结果,以及历史强震破裂分布特征,分析认为,花东纵谷断层南北段运动方式存在差异性,北段主要以强震形式运动,南段以蠕滑和地震两种形式运动。自1951年花莲-台东ML 7.3地震序列后,花东纵谷断层南段、中段和北段至2016年所累积的矩能量分别等价MW 6.4、MW 7.0、MW 7.4地震;若发生级联破裂,整个断层至2016年所累积的矩能量等价MW 7.5地震。     

顶部电离层离子密度经度结构的特征及其随季节、太阳活动和倾角的变化

本文利用DMSP卫星测量数据和傅里叶分解和重构方法,研究了地磁平静期顶部电离层总离子密度(Ni)经度结构的多重波数特征及波数4的年变化、逐年变化、地方时差异和随倾角的变化.傅里叶分解和重构的结果表明,顶部电离层平均Ni的经度结构中同时含有以波数1至波数4为主的多重分量,不同波数分量的幅度和相位各不相同.对波数4分量的分析表明,波数4的幅度在春秋季最强,北半球夏季高于冬季;随太阳活动水平增强,波数4分量的幅度增高,至太阳活动高年幅度达到最高,此后随太阳活动水平降低而减小,与F10.7呈正相关;春秋季和北半球夏季波数4分量在傍晚最强,晚上和上午次之,黎明最弱,从09LT到21LT,波数4的相位依次滞后,暗示向东移动.分析还发现,日落期间波数4幅度依赖倾角,春秋季随倾角的变化呈双峰结构,两个极大出现在倾角±18°附近,暗示赤道等离子体喷泉效应对顶部电离层经度结构的控制作用.     

Erosion, sediment transportation and accumulation in rivers

The present paper analyses the interrelation between erosion, sediment transportation and accumulation proposed by N. I. Makkaveyev （1908-1983） and its further development in modem studies of river channel processes in Russia. Spatio-temporal linkages between erosion and accumulation are defined considering channel processes at different scales - river longitudinal profile, channel morphological patterns, alluvial bedforms （bars, dunes） and individual sediment particles. Relations between river geomorphic activity, flow transportation capacity and sediment budgets are established （sediment input and output; channel bed erosion and sediment entrainment into flow - termination of sediment transport and its deposition）. Channel planforms, floodplain segments separated by the latter and alluvial channel bedforms are shown to be geomorphic expressions of sediment transport process at different spatial and temporal scales. This paper is dedicated to the 100th anniversary of N. I. Makkaveyev, Professor of the Moscow State University, author of the book ＂River channel and erosion in its basin＂ （1955）. That book is regarded in Russia as the pioneering work which initiated the complex hydrological and geographical studies of channel processes and laid a basis for the theory of unified fluvial erosion-accumulation process.     

通量管积分瑞利-泰勒不稳定性的半球不对称和随经度变化的研究

本文利用通量管积分方法,对磁南北半球分别沿磁力线积分,研究背景电离层南-北半球不对称以及中性风场和磁偏角随经度的变化对广义瑞利-泰勒不稳定性和电离层不规则结构生成和发展的影响.结果表明,通量管积分广义瑞利-泰勒不稳定性线性增长率存在显著的半球不对称,南北半球不对称的中性风场是导致电离层不规则结构呈南北分布不对称的重要因素;随经度变化的中性风场和磁偏角对瑞利-泰勒不稳定性的经度变化有重要影响,它们可能是导致不规则结构出现率经度变化的主要控制因素.     

准噶尔盆地超压系统分布及其演化

钻井揭示准噶尔盆地超压明显,且不同地区超压出现的深度和层位不同。本文将准噶尔盆地在纵向上划分为上部、中部和下部3套超压系统。上部超压系统顶界受古近系安集海河组控制,底界受下白垩统胜金口组控制,构成压力封存箱。中部超压系统的封隔层为三工河组,构成顶封滞排型异常压力系统。下部超压系统发育在三叠系及以下地层之中,以白碱滩组为封隔层构成顶封滞排型异常压力系统。三者在平面上有不同的分布范围。白垩纪是准噶尔盆地超压形成的开始期,新近纪得到进一步加强。其中,下部超压系统开始形成于白垩纪早期,中部超压系统开始形成于白垩纪中期,而上部超压系统形成的最早时期应为中新世。     

黄淮海平原河流的纵剖面凹度特征

本文以黄淮海平原为例,对于冲积河流纵剖面凹度的形成机理及其与不同河型的关系,进行了初步探讨。     

超高能宇宙线大气簇射平均纵向发展曲线的测量（英文）

利用HiRes宇宙线实验的观测数据,通过扣除测量信号中的切仑科夫光成份,测量了广延大气簇射的纵向发展曲线。把所有的纵向发展曲线归一并且平均,获得平均纵向发展曲线。根据所得曲线,检验了3个簇射模型,它们都能较好地描述纵向发展曲线。如果利用高斯函数来描述簇射的纵向发展曲线,发现纵向发展曲线的宽度（σ）与簇射发展最大的深度有一定的关联,而且该参量从1017eV到1020 eV能量范围内几乎保持不变。另外还对平均纵向发展曲线的不确定性进行了讨论。