我的南极故事(一)

我想讲的第一个故事就是我是怎么加入中国南极科学考察队(简称中国南极科考队或中国南极考察队)的,因为有许多好奇或自己想加入的人会来问我这个问题.     

河南“乡村规划千村试点”工作正式启动

本刊讯7月15日,记者从河南省自然资源厅获悉,由该厅牵头组织开展的“乡村规划千村试点”工作正式启动,届时将邀请1517名优秀规划专家深入全省1188个试点村庄开展规划编制指导服务,为全省开展“多规合一”的实用性村庄规划编制工作提供可复制、可推广的经验。     

与春天有个约会

春天到了,万物复苏,生机渐浓,璀璨温馨的春夜星空,如约而至。人们对春天星象归结为"参横斗转(猎户座横于西天),狮子怒吼(狮子座是春季星空最为壮丽的星座),银河回家(春夜星空,银河沉于地平线之下,春不能看见),双角东守(牧夫座的大角星和室女座的角宿一,正在东方天空熠熠发光)"。本文就春季星空中的一些重要星座以及可观测天体做一个概要性的梳理,让我们与春夜星空有一个愉快的约会。     

最亮行星邂逅最暗行星——如何成功观测到海王星

你的行星观测列表上还有哪个天体没有打上勾?太阳系中除了地球,还有七颗行星。在地球上看,它们大部分都很明亮,每个人或多或少都见过它们中的几颗。有个别行星观测起来不是那么容易,如果不是有计划地寻找,是很难偶遇的。图1总结了太阳系行星的亮度范围,其中金星、火星、木星和土動亮不钱低,全年大部分时麵能轻易姻它们。     

青岛观象台太阳黑子观测的历史与现状

一百二十多年前,德国人怀揣殖民目的,建立了青岛观象台。而将青岛观象台发扬光大的是我国现代科学的先辈们。他们孜孜以求,用一支笔、一台镜子、一颗热忱的心指向距离我们最近的恒星——太阳,并揭开了它的神秘面纱。     

穿越生死空间——甘肃省地震灾区次生地质灾害调查纪实

地震!这是黎志恒在感觉到大地的颤动之后脱口而出的第一句话。当时他正在甘肃兰州单位的办公楼里和同事谈工作。在大地颤动的间隙,黎志恒说出了第二句话:要镇静!当在大地颤动结束半小时后,黎志恒获悉:5月12日下午14时28分,四川汶川发生7.8级大地震!波及到甘肃陇南、甘南等地。到当天下午四时,当人们的注意力集中于地震造成的伤亡数字、如何抢救埋在废墟里的生命以及如何防御余震等问题时,身为甘肃省地质环境监测院院长的黎志恒,按甘肃省人民政府预案,—果断地启动设在该院的"甘肃省地质灾害预警应急反应系统",对地质灾害隐患点加强监测预警。汶川地震第二天,5月13日,甘肃省地矿局紧急派出地质专家奔赴灾区,并指示在陇南、甘南野外从事地质工作的局属队伍迅速展开抗震救灾,以地勘局的技术优势,担起灾区地震次生地质灾害调查评估工作……     

新闻稿共享开放的世界——首届国际GIS高校开源大赛在京启动

3月31日,2007'SuperMap杯国际GIS高校开源大赛暨第五届全国高校GIS应用开发大赛在北京师范大学举行,标志着我国首个开源GIS高校赛事正式在京启动,这也是目前全球惟一的国际GIS高校赛事.     

On the Physical Processes in Contact Binary Systems

Three importantphysical processes occurringin contact binarysystems are studied. The first one is the effect of spin, orbital rotation and tide on the structure of the components, which includes also the effect of meridian circulation on the mixing of the chemical elements in the components. The second one is the mass and energy exchange between the components. To describe the energy exchange, a new approach is introduced based on the understanding that the exchange is due to the release of the potential, kinetic and thermal energy of the exchanged mass. The third is the loss of mass and angular momentum through the outer Lagrangian point. The rate of mass loss and the angular momentum carried away by the lost mass are discussed. To show the effects of these processes, we follow the evolution of a binary system consisting of a 12M and a 5M star with mass exchange between the components and mass loss via the outer Lagrangian point, both with and without considering the effects of rotation and tide. The result shows that the effect of rotation and tide advances the start of the semi-detached and the contact phases, and delays the end of the hydrogen-burning phase of the primary. Furthermore, it can change not only the occurrence of mass and angular momentum loss via the outer Lagrangian point, but also the contact or semi-contact status of the system. Thus, this effect can result in the special phenomenon of short-term variations occurring over a slow increase of the orbital period. The occurrence of mass and angular momentum loss via the outer Lagrangian point can affect the orbital period of the system significantly, but this process can be influenced, even suppressed out by the effect of rotation and tide. The mass and energy exchange occurs in the common envelope. The net result of the mass exchange process is a mass transfer from the primary to the secondary during the whole contact phase.     

Global correlation for strontium isotope curve in the Late Cretaceous of Tibet and dating marine sediments

87Sr/86Sr ratios of marine carbonate samples collected from a sedimentary section of the Late Cretaceous in the south of Tibet were measured. Based on the absence of cathodo-luminescence and a very low Mn/Sr ratio (average 0.06) of the samples, it is thought that they contain information on the original seawater strontium isotope composition. The strontium isotope evolution curve of the Late Cretaceous in Tibet we established here, is consistent with other coeval curves from Europe, North America and Antarctica, supports the notion that the strontium isotope composition of seawater is governed by global events, which provides a new approach for the inter-continental and inter-basinal correlations of Late Cretaceous in the area and is a complementarity for biostratigraphy. In addition, we attempt to determine the age of the boundaries for Campanian/Santonian and Maastrichtian/Campanian by 87Sr/86Sr ratios for Gamba section in southern Tibet. The two boundaries are located in the thickness of 217 m (83.5 M