横穿贝加尔湖山脉北部寒区的线性工程     

I.Y. Malchikova 《冰川冻土》2004,26(Z1):206-209

The development of North Transbaikalye mineral resources (e. g. the Chiney deposit of iron titanium-vanadium-magnetite ores and Udokan copper deposits) is impossible without the establishment of industrial and transport infrastructure, one component of which are linear engineering constructions (drive railways, by-line auto roads, platform passages, protecting constructions, and others). However,on condition of spreading permafrost rocks this is conjugated with certain ecological risk just as from the transport network objects so for the objects themselves. A special attention is paid in the paper to considering of problems of projecting and constructing railways on the Udokan ridge.  相似文献   

探测冰盖和多年冻土层的融冰探头研发     

Norbert I. K 《冰川冻土》2004,26(Z1):310-318

The exploration of ice sheets by melting vertical holes into the ground has some tradition in terrestrial glaciology. Such probes have been used since the 1960's to investigate the vertical structure of the ice in Greenland and Antarctica and in alpine glaciers. In this paper we look into the possibility to develop similar devices for use on extraterrestrial icy bodies, like e.g. the polar areas on Mars or the icy satellites of the outer solar system. We report on some basic experiments performed in the cryo-vacuum laboratory of the Space Research Institute of the Austrian Academy of Sciences, Graz. In these experiments the penetration of a simple melting probe into compact and porous water ice (with a snow-like texture) was monitored, both under vacuum conditions and under air pressure. The observed penetration speeds for a given power supply are compared with a simple mathematical model. We conclude that a miniature melting probe with small overall dimensions and a reasonable power demand could well be part of the payload of a future planetary mission, for example to the poles of Mars. Such missions are currently under discussion in several space agencies. Moreover such probes could also e? ectively be used in terrestrial environments. A possible design is presented at the end of the paper.  相似文献   

论非均匀断层滑动弱化速率的标定     

H．Rerfettini M．Campillo I．Ionescu王文旭  胡凤英郭德科 赵爱华 《世界地震译丛》2004,(6):33-38

尝试用二维断层模型来描述断层在不稳定开始时滑动弱化速率的定标律。断层由一系列受滑动摩擦力作用变弱的片区组成，这些片区被牢固的障碍体所分隔。第一组断层包含不同尺度总滑动长度相同的片区的平均分布，而第二组断层由各种分形康托尔集合组成。破裂的整体活动性质由指数增长率λ来描述。对无限均匀的断层，系数λ由摩擦定律的弱化速率控制。在非均匀断层系中我们估算每一个断层的弱化速率，因为一个断层系的指数增长率λ与均匀断层是一致的。利用这种均匀断层的破裂过程，我们根据不同尺度均匀性断层和给定的系数λ来计算弱片区上的弱化速率。对于大尺度的破裂，弱化速率与尺度无关，长片区的开始过程类似于无限断层的破裂情况。本文考虑的是小尺度和所有不同几何形状的破裂，弱化速率记为α=β0^*／a，其中a为破裂尺度或者单个断层长度的一半，β0^*≈1．158。本文计算了滑动弱化距离Dc的值，在此基础上讨论了计算结果的物理含义，并给出了这个参数与尺度相关的可能解释。  相似文献   

A precise monitoring of snow surface height in the region of Lambert Glacier basin-Amery Ice Shelf,East Antarctica   总被引：2，自引：0，他引：2  

I.Allison 《中国科学D辑(英文版)》2005,48(1):100-111

The net surface snow accumulation on the Antarctic ice sheet is determined by a combination of precipitation, sublimation and wind redistribution. We present a one-year record of hourly snow-height measurements at LGB69 (70°50'S, 77°04'E, 1850 m a.s.l.). east side of Lambert Glacier basin (LGB), and 4 year record at G3 (70°53'S, 69°52'E, 84 m a.s.l.), Amery Ice Shelf (AIS). The measurements were made with ultrasonic sensors mounted on automatic weather stations installed at two sites. The snow accumulation at LGB69 is approximately 70 cm. Throughout the winter, between April and September, there was little change in surface snow height (SSH) at the two sites. The negative SSH change is due to densification at LGB69, and is due to both ablation and densification at G3. The strongest accumulation at two sites occurred during the period between October and March (accounting for 101.6% at LGB69), with four episodic increasing events occurring during 2002 for LGB69, and eight events during 1999-2002 for G  相似文献   

海南博螯沿岸地貌与人类活动的潜在影响     

朱大奎  殷勇  I.Peter Martini 《地理学报(英文版)》2005,15(2)

The Boao coastal system along the eastern coast of Hainan Island is a dynamic delta-tidal inlet-barrier formed during the late Holocene. The delta developed inside a shallow lagoon barred by a sandy barrier with a narrow, shallow tidal inlet opening. Two major distributary channels separated by small islands characterize the delta. The lagoon is silting up receiving and trapping sediments from both the river and, in minor measure during storms, through the tidal inlet opening and barrier washovers. The barrier at the tidal inlet is highly dynamic and changes its form, accreting (migrating spit) against the inlet during fair-weather conditions and being eroded during storms and river floods.The delta has almost completely filled the lagoon and major concerns exist on the effect that ongoing large development plans may have on the environment. These concerns include the effect on floods and rate of siltation once banks of the islands have been stabilized and floodwater and sediment load are impeded from spreading over the lowlands, and the effect of increasing pollutant loads from the new facilities on the ecosystems of the increasingly restricting lagoon water and on the seashores.  相似文献   

Unique Marine Olenekian-Anisian Boundary Section from South Primorye, Russian Far East     

Yuri D Zakharov Alexander M Popov Galina I Buryi 《中国地质大学学报(英文版)》2005,16(3):219-230

INTRODUCTION LateOlenekianandAnisianmarinedepositsin SouthPrimoryewerefirststudiedbyD.L.Ivanov,thechiefofageologicalteammakingreconnaissance workfortheconstructionofthetrans Siberianrail road.HecollectedEarlyandMiddleTriassicam monoidsonRussianIsland.Arep…  相似文献   

基于2002-2018年MODIS数据的黄海叶绿素a时空变化研究     

田洪阵  刘沁萍  Joaquim I. Goes  Helga do Rosario Gomes  杨萌萌 《海洋通报》2020,39(1):101-110

浮游植物作为食物链的基础,对海洋生态系统具有重要影响。黄海作为我国重要的渔场,渔业资源面临枯竭的危险,因此对该区浮游植物进行研究具有重要意义。叶绿素a浓度是反映浮游植物生物量的重要指标。利用谷歌地球引擎平台对2002-2018年的MODIS Aqua叶绿素a浓度数据进行处理,并研究其时空分布与变化特征,然后结合区域气候、水文与地理特征以及海洋表面温度、风速、盐度、光合有效辐射和混合层厚度数据分析了其分布与变化的原因。研究发现:受陆源营养物质输入、近岸上升流以及黄海中央冷水团影响,叶绿素a浓度分布呈现由近岸向黄海中部递减特征;在季风、气候、水文的控制下,受风速、海洋表面温度、光合有效辐射、中央冷水团的影响,叶绿素a浓度的最大值出现在4月份,而最小值出现在6、7月份;受苏北沿岸海域海水污染和水体富营养化影响,沿岸海域盐度明显增加,海州湾叶绿素a浓度增速较大;影响黄海叶绿素a浓度变化的环境因子较复杂,除了部分月份存在显著的相关影响因子外,在全年和各季中不存在主导影响因子。  相似文献   

Porphyry Deposits of the South Urals: Rhenium Distribution     

Olga Yu. PLOTINSKAYA  Anatoly I. GRABEZHEV  Reimar SELTMANN 《《地质学报》英文版》2014,88(Z2):584-586

Please refer to the attachment(s) for more details  相似文献   

近20年渤海叶绿素a浓度时空变化   总被引：3，自引：0，他引：3  

田洪阵  刘沁萍  Joaquim I. Goes  Helga do Rosario Gomes  杨萌萌 《海洋学报》2019,41(8):131-140

浮游植物作为食物链的基础，对海洋生态系统具有重要作用。渤海作为我国最大的内海和重要渔业生物的产卵场、育幼场和索饵场，该区浮游植物研究具有重要意义。叶绿素a浓度是反映浮游植物生物量的重要指标。利用Google Earth Engine平台，对1997–2010年的宽视场海洋观测传感器(SeaWiFS)叶绿素a浓度数据和2002–2018年的水色卫星中分辨率成像光谱仪传感器(MODIS Aqua)叶绿素a浓度数据进行合并，并研究其时空变化特征。研究表明，近20年来，渤海全年叶绿素a浓度增加了14.1%，且增加显著。叶绿素a浓度在所有季节都呈现增加趋势；除11月外，其他各月都呈现稳定或增加趋势。从滦河入河口沿岸至渤海海峡的渤海中部，叶绿素a浓度增加较明显。同时也分析了海洋表面温度、风速和降水量数据。夏季渤海周边区域降水量和风速增加以及秋季海表温度的降低都有助于同季叶绿素a浓度的升高。渤海浮游植物可能受陆源营养物质输入影响较大。  相似文献   

应用二次离子质谱定量分析矿物中的稀土元素     

I.J.Muir  陈淑桂 《世界地质》1989,(2)

利用下列技术对独居石和辉石样品中稀土元素(REE)进行了定量分析:(a)样品分离二次离子质谱法(SISIMS);(b)仪器中子活化分析(INAA):(c)电子探针显微分析(EPMA,仅独居石样品,(d)常规的能量渗滤法(CEFSIMS)的SIMS(仅独居石样品)。矿物晶粒中REE的含量范围从独居石的高含量(wt％)到辉石的ppm级。用CEF和SI两技术的SIMS分析同其它分析的结果非常一致,这表明可以把SIMS应用于矿物中的REE分析。辉石晶粒的分析表明:使用样品分离的SIMS,其检测限在ppm到近于ppm范围。  相似文献