青藏高原的范围

青藏高原确切的范围各家说法不一,本文根据青藏高原巨构造地貌特征,提出以高原面及其海拔高度为确定青藏高原范围的依据,对青藏高原具体范围特别是东、东南的边界作了较详细的讨论。     

Range expansion and potential distribution of the invasive grass Bromus tectorum in southern South America on the base of herbarium records

We reconstructed the invasion history and modelled the potential distribution of the invasive grass Bromus tectorum in southern South America. On the base of herbarium data, we described two aspects of B. tectorum's range expansion over time: area of occupancy and extent of occurrence. A maximum entropy model was used to identify both climatic variables associated with B. tectorum's current distribution and potentially invasible areas. The area-of-occupancy curve showed a steady increase of the occupied area since the first collection in 1937, with no obvious asymptote. However, the extent-of-occurrence curve indicated that range expansion was not homogeneous through time, but faster between 1965 and 1980. Most invasible areas were arid and semiarid with markedly Mediterranean precipitation regime. Within this susceptible region, there were large areas containing only a few known records of B. tectorum. Our results indicate that B. tectorum has successfully expanded over much of southern South America. In addition, there seems to be room for further local invasion (i.e. an increase of its area of occupancy) over large susceptible areas within the invaded region. Overall, our results confirm the suitability of southern South America's arid environments to B. tectorum invasion, and stress the importance of long-distance dispersal in accelerating its expansion across the region.     

漳华龙地区地磁异常与地震对应关系分析

选取龙岩台的地磁资料,总结漳华龙地区震例,用压磁效应、感应磁效应等理论解释、分析地震与地磁异常的对应关系。结果表明,不同类型的地震,在孕育地震的不同时期,有不同的地质构造运动,产生的地磁异常也是不尽相同的。地磁异常的显著程度不仅与地震的应力降、震级、以及岩石的磁性有关,还和震源机制关系很大。     

玉米生育期热量指标及其不同品种的栽培北界

利用玉米分期播种资料,分析不同发育期发育速度与温度的关系得出：在作物营养生长期,用有效积温作为热量指标比较稳定;播种到出苗期,不同品种的生物学下限温度基本在８℃左右;出苗到抽雄所需的有效积温可用品种的叶片数来计算,有效积温与叶片数关系可以写成ｙ＝３０．２ｘ＋３１．８;进入繁殖生长期,用＞１０℃积温作为抽雄到成熟的热量指标,并用抽雄期进行订正。用播种到成熟各发育阶段的热量指标来确定能否成熟和因成熟度所造成的减产程度。把品种在８０％年份能够成熟的地区作为品种栽培的北界。     

历史地理学研究领域框架及若干说明

本文提出了一个历史地理学研究领域框架(共三层44项)。历史地理学研究领域应包括学科基础理论研究和历史地理研究两部分,从研究实践考察,后者应包括描述历史地理学、理论历史地理学、应用历史地理学三大系列。本框架显示了历史地理学研究领域合理的层次关系。