共查询到20条相似文献，搜索用时 281 毫秒
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中国地震台网中心援建老挝国家地震监测台网 总被引：1，自引：1，他引：0
在"一带一路"建设倡议下,中国地震台网中心援建老挝国家地震监测台网,为期3年,现已初步完成台网建设工作。项目的实施,彰显了中国软实力,推进了中国"走出去"战略的发展。 相似文献
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杨建思 《地震地磁观测与研究》2015,(2):2
<正>"八五"期间,中国提出发展自己的数字地震观测系统,比西方落后近20年,形成的数字地震观测系统分为台网、流动台网和台站3部分。区域台网和流动台网的试验系统分别在北京遥测地震台网和江苏省地震局进行试验,发现并提出了一系列问题。"九五"期间,对改进后的自主研发数字地震现测系统在部分区域台网推幵,改进、推广经历了一段艰辛的历程:经过设备与软件改进, 相似文献
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《地震地磁观测与研究》2016,(4)
正从1996年开始,中国地震局进行了大规模数字地震观测系统建设,通过"中国数字地震监测系统""中国数字地震观测网络"和"中国地震背景场探测"3个重点项目的实施,已建成由国家地震台网、区域地震台网和流动地震台网组成的数字地震观测系统。(1)国家地震台网。国家地震台网是一个覆盖中国的地震监测台 相似文献
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河南省区域数字测震台网监测能力分析 总被引：2，自引：1，他引：1
收集河南省区域数字测震台网建台堪选资料及纳入该台网的外省地震台地震仪噪声背景资料,利用测震学模拟观测仪放大倍数与数字化地震仪噪声背景之间的关系,初步分析该省"十二五"建成台网的地震监测能力,预估"十三五"规划新增预警台后地震的监测能力。 相似文献
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"十五"数字地震观测网络项目完成以后,区域数字地震观测台网的台站数量有较大增加,观测系统更加先进,为充分发挥台网的监测功能,加强台网的运行维护管理和提高台网运行率是关键.本文介绍了江西省数字地震观测台网在运行维护实践中的一些方法和经验. 相似文献
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"九五"数字化地震前兆台站整体接入因特网的研究 总被引：1，自引：0，他引：1
介绍了如何将"九五"数字化前兆台站设备整体接人因特网,提供了一种非常简便、实用的整体接人方案.台站原来的构成模式没有改变,台网中心和台站熟悉的原工作方式得到了保留,实现了台站网络化的目标,使现有台网在因特网环境下能够正常运行.它能够与"十五"新建的前兆台网进行集成,便于整个台网的统一管理. 相似文献
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《Limnologica》2021
Karst springs represent valuable and often the most threatened habitats in the riverine landscape. Unlike other stream habitats, they have several specifics that determine their insularity in the river continuum, e.g., high seasonal thermal and chemical stability. The presented study aimed to find out the taxonomical and functional richness of three groups of aquatic insects (Ephemeroptera, Plecoptera and Trichoptera) in the Western Carpathians karst springs, as well as uncover the mechanism of the EPT community assembly. Low within-site species richness was generally found, however, there was high between-site diversity and thus high total diversity of the studied groups of benthic invertebrates as well. Species richness of the EPT community was higher in larger and colder springs: those with lower concentrations of CO2 and Fe, as well as higher concentrations of SO42−. Analysis of functional richness, as well as functional dispersion, did not reveal any clear assembly mechanism in the spring EPT community; however, both analyses indicated a higher proportion of environmental filtering there. Unlike the taxonomic richness, the functional richness of the EPT community was significantly higher in small and medium springs with higher water temperatures, as well as in springs with the presence of deadwood. Between-site dissimilarities in the functional composition of EPT were significantly correlated with environmental differences of springs, which determined variables such as spring size and temperature, as well as the concentration of CO2 and SiO2. 相似文献
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Mesozoic radiolarian chert from the middle sector of the Yarlung Zangbo suture zone,Tibet and its tectonic implications 总被引：1，自引：1，他引：1
ZHU Jie DU Yuansheng LIU Zaoxue FENG Qinglai TIAN Wangxue LI Jinping WANG Changping 《中国科学D辑(英文版)》2006,49(4):348-357
The middle sector of the Yarlung Zangbo suture zone stretches over 200 km long from Ngamring through Geding to Rinbung, roughly along Yarlung Zangbo River valley (Fig. 1). This belt resulted from the closure of the Tethyan ocean and the collision be- tween Indian plate and Lhasa block[1―8]. Lots of works demonstrated that rifting of the Tethyan basin in southern Tibet started from Triassic time. Initial oce- anic crust appeared in the Late Jurassic, and then ex- perienced a rapid sprea… 相似文献
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Geophysical prospection employing magnetometry and electromagnetic measurements has been applied in and around two small sized pyramids of Hellenikon and Ligourio in Argolid, Greece. The magnetic anomalies appropriately assessed were interpreted as possible archaeological targets. Subsequent test excavations revealed the presence of room foundations and parts of walls, as well as a plethora of ceramic ware. Typological study of the ceramics classified them to as early as the proto-Helladic period and to as late as the first centuries A.D. The earlier periods have been also confirmed by a novel application of thermoluminescence (TL) dating of ceramics and the megalithic stones themselves. The present results question earlier attempts classifying these pyramids at the Classical period and favour much earlier periods. 相似文献
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Mining,Environmental, Petroleum,and Engineering Industry Applications of Electromagnetic Techniques in Geophysics 总被引：6，自引：1，他引：5
Electromagnetic (EM) techniques are extremely important as a direct detection geophysical tool utilized in the base metal
industry. They were developed in countries such as Canada, whose thin conductive weathering overburden did not hamper the
penetration of EM signals and enabled exploration to depths on the order of 300 m. As a result, EM techniques were used widely
in North America and Scandinavia for many years before they became common in countries with a thick conductive overburden,
such as Australia. The 1980s and 1990s have seen the use of EM methods move from anomaly finding to mapping, as well as the
development of better, faster and more accurate computer modelling algorithms. A review of EM papers, for the years 1998 to
2002, showed that most dealt with EM techniques as mapping tools. Airborne, ground and marine EM techniques are still being
developed, as are data processing and interpretation software. The advent of robust 2-D and 3-D computer modelling and inversion
algorithms has led to the acceptance of EM methods as a mapping tool for many environmental and petroleum industry applications,
a trend which is expected to increase. 相似文献
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The process of aquifer recharge by flood events in an arid region was investigated as applied to the Hazeva Formation (the Karkom graben, the Wadi Paran watershed, Israel). The hydrological model was established as a complex system, with due regard for groundwater and transmission losses of surface runoff. It was based on a previously outlined hydrogeological model of the Karkom graben and a model of transmission losses in arid watercourses under conditions of data deficiency. Proceeding from calculation of groundwater balances, the contribution of surface runoff as a decisive balance component was confirmed. The main characteristics of aquifer regimes, such as changes in storage volume and groundwater level, as well as lateral flow, were all found to be dependent upon the net extraction rate, i.e. pumpage discounting replenishment by flood events. Analysis and physical interpretation of model parameters enabled assessment of the influence of groundwater extraction on aquifer recharge. This became apparent as increasing absorption capacity and recharge availability of the aquifer as a result of the groundwater abstraction. Copyright © 2002 John Wiley & Sons, Ltd. 相似文献
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地层渗透率与水合物含量关系的模拟研究(英文) 总被引：1，自引：1，他引：0
本文通过人工变换T2分布和建立管-球模型模拟法研究含水合物地层渗透率与水合物含量之间的关系。首先,在渗透率的模拟试验中,我们改变了束缚水与可动水的比例、总孔隙度以及与之关联的T2分布。试验结果表明,相对渗透率与水合物含量之间的关系受到这些因素的制约。随后,我们用管-球模型表示水合物生长的孔隙空间,并把水合物的生长过程看成是向孔隙空间随机扔小球的过程。在此过程中,采用两种方法计算渗透率,一是Schlumberger’sT2公式(即SDR模型),二是Darcy定律与Poiseuille流动方程相结合的方法。前人的实验研究表明,在一定的水合物含量范围内,渗透率基本保持不变。以此为参考,我们将计算结果与之进行比较。我们发现,采用SDR模型时,渗透率的数值模拟曲线与Masuda模型N=15时的结果相近。而采用Darcy定律时,渗透率模拟值较高,但与实验结果的趋势相一致,都会出现渗透率的平直阶段。尤其,当水合物晶体在孔隙体内优先生成时,优先的概率越高,渗透率的平直范围越大。 相似文献
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The Estuarine Quality Paradox, Environmental Homeostasis and the difficulty of detecting anthropogenic stress in naturally stressed areas 总被引：2，自引：0，他引：2
Estuaries have long been regarded as environmentally naturally stressed areas because of the high degree of variability in their physico-chemical characteristics, for example oxygen, temperature and salinity in the water column and bed sediment dynamics. However, their biota is well-adapted to cope with that stress and so the areas may be regarded as resilient because of that inherent variability; their ability to absorb stress without adverse effects is regarded here as Environmental Homeostasis. Hence these areas may only be regarded as stressful for marine or freshwater-adapted organisms and that for estuarine organisms this environmental stress is regarded as a subsidy whereby they successfully capitalise on the stressful conditions. In addition, using examples of the estuarine fauna and flora, this article indicates that the characteristics of natural stress in estuaries are similar to those for anthropogenic stress. An over-reliance on ecosystem structural features, such as diversity, in quality indicators therefore makes the detection of the anthropogenic stress more difficult. This difficulty is termed the Estuarine Quality Paradox. Because of these difficulties, the article argues that functional characteristics either as well as or rather than structural ones should be used in detecting environmental perturbations in estuaries. 相似文献
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In accordance with the natural, geographic, and ecological characteristics of the Taihu Lake Basin, and the relation between the water body of Taihu Lake and its surrounding environment, an area, which has tight relevance with the water environment of Taihu Lake, was token as the main investigation region. The area was named as the Taihu Lake Region. Some factors, such as TN, TP, CODCr that characterized the main environmental problem, the eutrophication were selected when conducted the pollution sources investigation on in Taihu Lake Region. The categories, distribution, pollution contribution to the Lake of dijferent pollution sources, as well as the routes of pollutants entering the Lake were basically made clear. Pollution sources that must be preferentially controlled and the direction of controlling those main pollutants, such as TN, TP, CODCr, were proposed. Base on the investigation, a series of eco-systematic approaches for controlling Taihu Lake eutrophication were put forward. They are ecosystem regulation, nutrient substances transferring along food chain, trophic masse degrading step by step along the route from a pollution source to the Lake, building ecological preventive zone of the Lake, as well as the ecological measures for point sources treatment and so on. 相似文献
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Significance of fossilized microbes from the Cambrian stromatolites in the Tarim Basin,Northwest China 总被引：2，自引：0，他引：2
Samples of the Cambrian microbial dolomites were collected from Penglaiba section,a well-exposed stratigraphic section in the northwestern area of the Tarim Basin.This study provides an analogue for mediated dolomites that can precipitate in microbial mats and biofilms.The Cambrian stromatolitic dolomites were studied using high-resolution scanning electron microscopy.The results are as follows:(1)dolomites with 50 nm to 100 nm spherical nanostructures are aggregated into minerals of larger sphericities;(2)nanospherical dolomites of 50 nm to 170 nm diameter are densely arranged as dumbbell-shaped or chained aggregates;(3)silicified filaments,as well as dumbbell-shaped and chain arrangements,are preserved as important microstructures.On the basis of sedimentological,compositional,geochemical,and petrographic data,the microstructures were interpreted as nanoglobules that function as bacteria in the nucleation and filament mineralization stages.The microstructures function as such because they are wrapped in extracellular polymeric substance(EPS)or mucus and mineralized fossils.Silicification accounts for the exceptional preservation of microbial mat structures,including biofilms,as well as filamentous and coccoid microbes.In addition,EPS process is capable of binding different elements,with preference for Si,Mg,and Ca.Such suitable composition favors microbe mineralization and dolomite nucleation on organic substrates.These microscopic structures suggest bacterial mineralization and provide visual evidence for the origin of microbial dolomites. 相似文献
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中央级救灾物资储备仓库在地震紧急救援中的作用 总被引：11，自引：0，他引：11
为了使灾民尽快得到物资救援，中央在天津、黑龙江、沈阳、合肥、郑州、武汉、长沙、南宁、西安建立了中央级救灾储备物资代储单位。本文介绍这些仓库的设置、构建、管理、现状和需要解决的问题。 相似文献