胶州湾叶绿素a及初级生产力的长期变化

采用野外观测与历史数据相结合的方法,系统分析了1984—2008年胶州湾叶绿素a及初级生产力分布格局、季节特征的变化以及长期变化规律。结果表明,近20年来胶州湾叶绿素a的空间分布格局没有发生大的变化,但季节规律发生了很大变化。冬季和夏季叶绿素a浓度升高,春季和秋季叶绿素a浓度下降,使得其双周期型的季节变化特点更为显著。...     

近50a来天山博格达峰地区四工河4号冰川表面高程变化特征

基于GIS技术,利用GPS测量数据和1962年地形图分别建立两期DEM,通过对比重点研究了四工河4号冰川1962-2009年冰舌区的表面高程变化特征。结果表明:1962-2009年间,冰舌区平均减薄15±10 m,年均减薄约0.32±0.2 m,冰储量亏损达(14.3±9.5)×10-3km3,折合水当量(12.9±8.6)×10-3km3。不同海拔、坡度区间冰面高程变化差异显著,海拔较低、坡度较缓区域的变化最为强烈。在气候变暖的趋势下,四工河4号冰川发生强烈消融,标志着博格达峰地区的冰川正处于物质严重亏损的状态,直接影响到流域水资源状况。     

Period Changes of Close Binary Systems

A brief review of the physical mechanisms that could produce the observed orbital period changes in close binaries, the methods used to study them, and a general discussion is given.     

长江三峡库首区近期重力场动态变化

利用向上解析延拓方法分析了1988～2003年底(首次蓄水后)长江三峡库首区重力场的动态变化，并分析了首次蓄水过程中重力变化的基本特征。主要结论有：库区存在一定的重力变化背景和地壳密度变异条件；向上解析延拓方法能较好地分离不同波数域重力变化特征，其中长波数信息反映较深处或较大尺度异常密度体效应；首次蓄水过程中的重力变化显示强烈的库水荷载效应和明显滞后的库水渗透效应，其中江北地区水的渗透明显强于江南地区。     

地震应变变化的理论量级与最大传递距离关系

为了与实际观测资料对比 ,用线弹性理论位错公式算出了各种断层的地震应变变化并进行了全面、系统的分析 ,归纳了一些特点 ,阐明了理论应变变化量级与其最大传递距离的关系。分析表明 :对于一定震级的地震 ,当断层出露地面、倾角为 4 5°、并且为倾滑运动时 ,一定量级的应变变化传递的距离最长 ;其中一个主应变传递得最远 ,其次为体应变 ,再其次为最大剪应变 ,另一个主应变的最大传递距离最短 ;泊松比和断层的长宽比的变化对应变传递距离的影响极小 ,可以忽略     

Benefits to Studies of Global Sea Level Changes from Future Space Gravity Missions

Global sea level rise will present a major scientific, environmental and socio-economic challenge during the 21st century. This paper reviews the main oceanographic and geophysical processes which contribute to sea level change, with particular emphasis on the ability of space gravity missions to contribute to an enhancement of our understanding of the various processes, and ultimately to a better understanding of sea level change itself. Of special importance is the need to understand better the ocean circulation, and the contribution of ocean thermal expansion to sea level change.     

Formation,mechanism and significance of alluvial-dammed lakes in Golmud River catchment,north-eastern Qinghai-Tibetan Plateau

This study investigated a series of dammed lakes and downstream-adjacent alluvial fans in the upstream to middle reaches of the Golmud River in the eastern Kunlun Mountain, on the north-eastern Qinghai-Tibetan Plateau (QTP). An optically stimulated luminescence (OSL) chronology shows the sediments of five dammed lakes developed from c. 45–40, 30–25, 18–14, and 12–8 ka, corresponding to MIS 3b, late MIS 3a, Last Deglaciation, and early Holocene, respectively. The remote sensing data show these dammed lakes have a total area of 109.4 km², with the lake volume of more than 4.0 km³. Symmetric alluvial fans from north–south tributary valleys produced OSL ages of c. 61–52, 42–31, 26–20, and 16–10 ka, corresponding to glaciation periods: the MIS 3c and MIS 3a, MIS 2, and the Last Deglaciation. This suggests that glacial activity is responsible for the alluvial fan development, where dammed rivers occurred first, but lake formation did not take place synchronously until later periods of strong hydrologic activity, resulting from northward intrusions of the Indian summer monsoon (ISM) or glacier melt. Thus, the blocking pattern is that river valleys were dammed during periods of glacial activity and lakes formed during wet periods. The lake formation and subsequent drainage may have resulted in: (i) impeded headwater incision and strengthening of downstream dissection; (ii) enriched the halite and potash in the distal Qarhan Salt Lake through hydrologic and hydrochemical processes of abundant water input, the salt lake expansion, salt redissolution from playa and final resedimentation during later dry periods. The alluvial-dammed lake pattern in the mountain-basin systems of eastern Kunlun Mountain offers a model for assessing the linkages between monsoon dynamics, geomorphic processes and distal salt lake evolutions in other arid regions.     

城市公园游憩行为的性别差异——以广州人民公园为例

以广州市人民公园为研究对象,通过实地踏勘和问卷调查,利用统计与观察分析方法解剖城市公园游憩行为的性别差异特征。在游憩者的行为和社会特征方面,两性之间存在明显差异;女性的公园游憩行为与其社会分工特别是家庭责任紧密联系;女性因对安全性的要求高而趋向视线开敞的集体区域活动,男性因要求独立性而趋向在有视线遮挡的区域活动,且男性同性恋活动区域对女性形成了一定的活动抑制;女性对出行距离较为敏感,而男性独自出行游憩的比例更高;女性对城市游憩空间的需求趋于稳定、有规律,也凸显了公园对女性日常生活的重要性。基于公平性与人性化原则提出相应的城市公园规划设计对策,特别应对公共设施进行细致而灵活的设计,以适应使用者的性别差异性;并应按照步行尺度进行游憩场所的规划布局,以保障女性就近游憩的需求。     

古地图与现代空间数据的河道变迁研究——以清代潇河为例

潇河是汾河的第二大支流,清代河道变迁频繁.本文利用清代山西地方志中的舆地图和现代空间数据,结合历史文献记载与实地考察,研究了潇河河道变迁最为剧烈的时期--清代近300年间的变迁过程,复原了不同时段的面貌,并对变迁原因进行了分析.认为在气候变干的大背景下,河道变迁的原因主要有两个:一是潇河及其支流泥沙含量大,造成旧河道的...