青藏高原东北部黄河源区大暖期气候特征

本文通过孢粉、有机碳和粘土矿物的分析,探讨了黄河源区全新世的气候变迁,重点论述了大暖期的气候特点。在全新世,黄河源区的气候总体凉干,属于高原的高寒气候。在大暖期,该区的气候较现今高2～3℃,显得湿润些,但波动较频繁,尤其是大暖期的后期波动剧烈,并在5．0kaBP前后发生一次剧烈的降温。记录表明,黄河源区的大暖期始于9．0kaBP,止于2．30kaBP,较我国其他地区开始得早,而结束得晚,其鼎盛时期为6．0kaBP前后。     

兰州地区最古老黄土剖面的粒度学及孢粉学研究

兰州地区最古老黄土剖面露头良好,地层出露较齐全,通过剖面磁性地层研究,确定兰州地区最古老黄土形成于1.84MaBP以前,对山城湾岭黄土剖面进行了粒度及孢粉的研究,探讨了第四纪沉积环境的演化。     

亚洲地震委员会(ASC)第七次学术大会暨日本地震学会(SSJ)秋季会议在日本筑波召开

由亚洲地震委员会和日本地震学会联合主办,日本多个学术机构参与协办的第七届亚洲地震委员会学术大会暨日本地震学会秋季会议于2008年11月24--28日在日本筑波(Tsukuba)举行.     

几个天然镁铝榴石的穆斯堡尔效应的研究

穆斯堡尔效应是一种无反冲的核γ射线的共振吸收现象,它是1958年由穆斯堡尔(R.L.M(?)ssbauer)发现的。由于穆斯堡尔效应产生的γ射线共振吸收谱线的能量宽度接近原子核能级的自然线宽,以及无反冲γ射线共振吸收(或散射)对γ射线能量变化十分灵敏,因此,可以把共振吸收的原子核当做灵敏的探针,测量固体中有关的原子核与核所在位置上固体的化学环境间的超精细相互作用。近些年来,穆斯堡尔效应已广泛应用于物理学、化学、生物学及矿物学的研究中来,穆斯堡尔谱仪已成为这些学科的重要研究工具之一。     

Review of Global Ocean Intermediate Water Masses: 1.Part A, the Neutral Density Surface (the ‘McDougall Surface’) as a Study Frame for Water-Mass Analysis

1Preface Todescribeoceanicintermediatewatermasses,itis necessarytohaveawell definedstudyframeorsurfacebecauseofthefluctuationnatureofintermediatewa ters.Itiswellunderstoodthatoceanicwater mass mixingdoesnotalignwitheitheraconstantgeopoten tialdepthorapropertysurfacesuchastemperature,salinity,pressureanddensitysurfacesbutfollowsa neutraldensitysurface.Thisisbecauseawaterparcelmovesasmalldistanceisentropicallyandadiabaticallyontheneutraldensitysurfacewithoutdoingworka gainstabuoyantrestoringforc…     

太阳物理学中的分形和混沌

对非线性科学的两个重要分支；分形和混沌在太阳物理学中的应用情况作了综述信要内容包括；太阳活动混沌性的揭示；对太阳活动混沌性的可能解释－太阳非线性发电机理论；一些太阳现象的分形描述；耀斑的自组织临界行为研究，最后给出了作者对这一领域工作前景的展望。     

Combining satellite and seismic images to analyse the shallow structure of the Dead Sea Transform near the DESERT transect

The left-lateral Dead Sea Transform (DST) in the Middle East is one of the largest continental strike-slip faults of the world. The southern segment of the DST in the Arava/Araba Valley between the Dead Sea and the Red Sea, called Arava/Araba Fault (AF), has been studied in detail in the multidisciplinary DESERT (DEad SEa Rift Transect) project. Based on these results, here, the interpretations of multi-spectral (ASTER) satellite images and seismic reflection studies have been combined to analyse geologic structures. Whereas satellite images reveal neotectonic activity in shallow young sediments, reflection seismic image deep faults that are possibly inactive at present. The combination of the two methods allows putting some age constraint on the activity of individual fault strands. Although the AF is clearly the main active fault segment of the southern DST, we propose that it has accommodated only a limited (up to 60 km) part of the overall 105 km of sinistral plate motion since Miocene times. There is evidence for sinistral displacement along other faults, based on geological studies, including satellite image interpretation. Furthermore, a subsurface fault is revealed ≈4 km west of the AF on two ≈E–W running seismic reflection profiles. Whereas these seismic data show a flower structure typical for strike-slip faults, on the satellite image this fault is not expressed in the post-Miocene sediments, implying that it has been inactive for the last few million years. About 1 km to the east of the AF another, now buried fault, was detected in seismic, magnetotelluric and gravity studies of DESERT. Taking together various evidences, we suggest that at the beginning of transform motion deformation occurred in a rather wide belt, possibly with the reactivation of older ≈N–S striking structures. Later, deformation became concentrated in the region of today’s Arava Valley. Till ≈5 Ma ago there might have been other, now inactive fault traces in the vicinity of the present day AF that took up lateral motion. Together with a rearrangement of plates ≈5 Ma ago, the main fault trace shifted then to the position of today’s AF.     

中国地震局代表团访问智利

应智利国家科学技术委员会 (CONICYT)邀请 ,以中国地震局刘玉辰副局长为团长的中国地震局代表团一行 5人 ,于 2 0 0 1年 3月 12～ 19日对智利进行了访问。智利是一个地震多发国家 ,2 0世纪在该国曾发生过一次 8.9级巨大地震 ,这是人类历史上迄今为止记录到的最大地震。智利地域狭长 ,地震多发生在北部和中部地区。目前 ,智利全国共有 5 0多个地震台 ,使用的绝大部分是短周期、单分向地震计 ,仅有 3个宽频带数字地震台装有 STS-2型地震计。其中 13个台采用无线电短波进行实时传输。智利大学等已经与法国、美国开展了合作研究 ,其中与美国…     

GIS APPLICATION IN RESEARCH OF WILDLIFE HABITAT CHANGE——A case study of the Giant Panda in Wolong Nature Reserve

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