全球变化生物迁移和地层界线──论希腊雅典地区第四系底界

全球环境的突然变化，可能引起全球性生物多样性跃升、全球性生物群体绝灭及生物群全球性迁移。为了阐明生物群的全球性迁移，我们应用了气候带中心种群及气候带边界种群的新概念。在第四纪初期，全球开始变冷，北半球寒冷气候带的生物群向南扩张，温带、亚热带乃至热带的生物群向南退缩，在这呈带状的整体的扩张和退缩过程中，气候带的边界种群总是比气候带的中心种群先期到达同一地区。就同一地区而言，边界种群的迁入，代表该区气候开始变冷，而中心种群的到达，则表示该区气候已进入最冷期，所以我们建议以气候带边界种群首次移入该区的时限，作为该区第四纪的开始。依据这一原理，我们把北温带北部的边界种Ｅｌｐｈｉｄｉｕｍｃｒｉｓｐｕｍ／ｍａ－ｃｅｌｌｕｍＳｐｅｃｉｅｓＧｒｏｕｐ在希腊雅典东Ｒａｆｉｎａ沿岸地区首次出现，作为该区第四纪的开始。     

Assessment of reservoir sedimentation effect on coastal erosion in the case of Nestos River,Greece

Coastal erosion that is generated by the reduction of the annual sediment yield at river outlets, due to the construction of reservoirs, constitutes one of the main environmental problems in many parts of the world. Nestos is one of the most important boundary rivers, flowing through Bulgaria and Greece, characterized by its great biodiversity. In the Greek part of the river, two reservoirs, the Thisavros Reservoir and the Platanovrysi Reservoir, have already been constructed and started operating in 1997 and 1999, respectively. The present paper constitutes the first attempt where the assessment of reservoir sedimentation effect on the coastal erosion for the case of the Nestos River delta and the adjacent shorelines is addressed in detail, through mathematical modeling, modem remote sensing techniques and field surveying. It is found that the construction and operation of the considered reservoirs have caused a dramatic decrease （about 83%） in the sediments supplied directly to the basin outlet and indirectly to the neighbouring coast and that this fact has almost inversed the erosion/accretion balance in the deltaic as well as the adjacent shorelines. Before the construction of the reservoirs, accretion predominated erosion by 25.36%, while just within five years after the construction of the reservoirs, erosion predominates accretion by 21.26%.     

希腊VAN地震预报方法的进展与争论(Ⅱ)--国际评价与争论

综合介绍了90年代以来国际上对VAN小组预报研究的评价和争论,包括评价的基本方法、三类评价意见以及评价中的几个主要争议问题等.     

希腊VAN地震预报方法的进展与争论(I)——进展

该文综合希腊ＶＡＮ小组成员及各国专家发表的有关论文,全面介绍了ＶＡＮ小组自８０年代初以来所进行的地电地震预报方法的探索和效果,包括观测技术、预报程序、地震三要素的估计、预报及对应情况,国际上的评价及争论等。全文包括两部分,即进展和国际评价与争论,本文是其中的第一部分。     

飓风送来的“铅笔”——英国人、德国人发明铅笔的故事

铅笔,顾名思义应当是铅做成的笔。然而我们现在所用的铅笔笔心的主要原料却是石墨而不是铅。之所以称其铅笔是因为很早以前,人们的确是用铅写字、记帐。据记载,我国在距今1900多年的东汉初期,就有人使用铅笔。在欧洲,早在希腊和罗马时期,也开始使用铅笔了。但这种名副其实的铅笔并不好用,铅条很容易折断,写出来的字     

伦敦公布奥运火炬传递路线

3月19日,伦敦奥组委公布了伦敦奥运火炬在英国境内的具体传递路线和7300名火炬手名单。奥运火炬于5月18日由希腊运抵伦敦,火炬传递将于5月19日从英格兰最西南端的兰兹角开始,并于7月27日奥运会开幕式当天到达奥运会主会场     

投影在地图上的希腊神话

大片《特洛伊》令人回味无穷．希腊足球队令人惊讶地获得欧洲杯冠军．雅典奥运会也刚刚落下帷幕……如果年底作一个“名词点击率”排名。“希腊”一定名列前茅。的确．希腊这个欧洲古国对人类文明的影响是广泛而深刻的，今天．就请大家和作者一起．在地图上寻找一些希腊神话的痕迹。     

希腊的“梦幻之岛”——圣特里尼

这座神奇的火山小岛．以它多彩多姿的表情．征服了每一双旅人们挑剔的眼睛——说真的．若出走只为找寻一座“梦幻之岛”，那么．舍圣特里尼岛其谁?     

Estimate of sediment inflow into Vistonis Lake, Greece

In the present study, the mean annual sediment inflow into Vistonis Lake (Thrace, northeastern Greece) was calculated. The sediment quantity originates mainly from the basins of Kossynthos, Kompsatos and Travos (Aspropotamos) Rivers. The whole basin area (mountainous part) contributing to the lake amounts to about 845 km². The above mean annual sediment quantity was compared with the mean annual sediment accumulation in the lake. The latter quantity was estimated from the mean annual decrease of the lake water volume for a period of 22 years, which was determined by means of older and newer topographic maps (isobath contours). For the calculation of the mean annual sediment yield at the outlets of the three above mentioned basins, a mathematical model consisting of three submodels was used: a rainfall-runoff submodel, a soil erosion submodel and a sediment transport submodel for streams. The comparison of the computational results by means of the mathematical model with the estimation results by means of the topographic maps is satisfactory and encouraging.     

最远的海,最近的海——电影《碧海蓝天》

在宁静的海岛小镇上,雅克和恩佐的友谊和较量从一枚硬币开始,童年愉快地穿梭于白色和蓝色之间,在希腊闪烁的阳光下,他们纵身一跃,各自寻找梦想.成了世界潜水冠军的恩佐心里清楚,只有童年的伙伴雅克才是他真正的对手.因为他们两个人,是离海最近的两个人.雅克和恩佐就这样在蓝色的背景下,一次次地潜入深海,恩佐为了征服海洋和雅克,而雅...