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1.
在多年工作的基础上,介绍了水氡仪器的标定方法,分析了水氡仪器常见故障的原因及判别、排除方法等,指出所介绍的方法可供仪器标定人员工作时参考。  相似文献   

2.
房屋抗震能力是地震灾害风险评估、震后损失快速评估等工作的关键数据。文章给出基于遥感影像和经验估计初步判别山西省建筑物抗震能力的技术方法,描述辅助性基础数据收集的类型、遥感数据的来源、判别标准的建立、针对城市或农村房屋特点的判别方法。据此,完成山西省房屋抗震能力的初步判别工作,并基于实地调研、街景对比、空间分析等方法进行数据质检。结果表明,该方法工作效率高、成本低,可快速获得区域房屋的空间分布、数量和基本的抗震性能。  相似文献   

3.
多次覆盖技术作为一种增强信号、压制干扰的方法,广泛用于地震勘探工作中,可以大大提高有用信号的信噪比。本文作者把多次覆盖技术引入探地雷达测量工作中,通过与剖面法作对比试验来论证多次覆盖技术在探地雷达勘探中应用的可行性及优缺点。作者根据试验资料总结探地雷达工作中雷达波传播规律、工作参数、资料处理方法,对丰富探地雷达勘探技术作了一次有益的尝试。  相似文献   

4.
新时期城市防震减灾宣传教育工作策略探讨   总被引:3,自引:0,他引:3  
本文通过对新时期城市特点的研究和分析,结合以往的地震科普工作,探讨了防震减灾宣传教育工作的新思路和方法,提出了在不同时期、针对不同对象的防震减灾宣传教育工作策略。  相似文献   

5.
对比折射法在苏联科学院甘布尔采夫院士的領导下研究成功。1952年出版了文献,书中論述了对比折射法的物理基础,推断解释方法和观測方法問題。此书已譯成中文。此后,在工作方法研究、理論研究和生产工作的基础土,对比折射法在理論物理基础、新工作方法的研究以及解决勘探任务方面都有了进一步的发展。今后对比折射法发展的主要方向是:扩大勘探頻率范围,查明用对比折射法所能研究的各种介貭类型。  相似文献   

6.
吴岩 《地球》2014,(5):108-109
深部找矿是当前矿产资源勘查工作的重点,需要新的理论和技术方法的支持。本文以在山东某金矿为例概述了该矿区的地质概况和地球物理特征,介绍了广域电磁的原理、仪器和工作方法,在该矿区开展广域电磁法勘探工作。通过对勘探结果的反演剖面图进行解译和推断异常,圈定靶位,验证了新型物探方法在深部找矿应用中的有效性。  相似文献   

7.
费敏 《地球》2012,(12):98-99
本文简述土地勘测定界在外业工作的基本要求、工作程序,并对针对土地勘测定界项目外业工作中容易出现问题的环节,简要介绍了一些以往工作的经验,并提出了一些个人的看法和建议及个别处理问题的方法。  相似文献   

8.
以CNEM08-Ⅰ型电扰动仪原有的采集方法、计算方法为基础,保留其数据采集模块原有的工作模式,对其工控机内部软件进行升级改造,使其工作更为稳定、数据完整率得到大幅提高,仪器通讯符合中国地震局"十五"前兆通信规程。  相似文献   

9.
房屋建筑数据是地震重点危险区预评估工作的基础,需基于获取到的房屋建筑信息开展人员伤亡、经济损失、救援物资需求等预评估工作。历年地震重点危险区预评估工作能够通过现场调查得到的房屋建筑信息占比极小,仅能进行抽样调查。因此,为批量完成危险区内全部房屋建筑损失估算,需基于遥感影像获取房屋建筑矢量数据,并建立数据库。为实现全国地震重点危险区预评估工作中大批量建筑物矢量化数据的快速获取,本文采用基于遥感影像的建筑物空间分布数据批量获取方法,得到地震重点危险区内建筑物空间矢量数据,结合现场抽样调查得到的建筑物属性信息,建立地震重点危险区建筑物空间分布数据库,进而为地震重点危险区灾害损失预评估工作提供数据基础。本文采用的方法可广泛应用于地震重点危险区房屋建筑信息获取工作中,可提高工作效率,降低工作成本,提升预评估工作的科学性和准确性。  相似文献   

10.
正地震区划工作对于地震灾害的综合防范,即土地利用规划、抗震设防和应急备灾具有重要的意义。应急备灾工作考虑未来短时间段内的地震危险性,需要时间相依的地震危险性区划工作。地震区划研究需要涉及到地震危险性分析工作。地震危险性分析方法分为确定性(Deterministic)方法和概率性(Probabilistic)方法。传统的概率地震危险性分析(Probabilistic  相似文献   

11.
藻类鉴定被广泛应用于藻类遗传学、生理学、生态学和应用藻类学,尤其是藻类调查和评估.然而,基于形态学的鉴定往往因为分类特征未出现或不典型、设备限制和人员经验欠缺等原因带来较大误差.随着测序技术的不断发展,分子标记已成为藻类鉴定的一个通用工具.由于藻类类群众多且差异很大,分子标记的选择成为藻类鉴定的关键.本文综述了蓝藻、硅藻、绿藻、甲藻、裸藻、隐藻、金藻、黄藻、红藻和褐藻等主要门类分子标记的选择及应用进展,包括分子标记选择原则、常用标记和相应序列数据库,以及各个分子标记在不同类群应用中的优缺点等.藻类分子鉴定源于编码核糖体RNA的基因(rDNA),发展于细胞核、线粒体、叶绿体DNA等.然而,当前藻类分子鉴定逐渐细化和完善,单一的核糖体DNA、内转录间隔区(ITS)和保守蛋白编码基因等短序列分子标记已经很难满足藻类鉴定的需求,多标记组合成为一种必然选择.同时,线粒体基因组、叶绿体基因组、核基因组、转录组和宏基因组等提供了更多遗传进化信息,弥补了短序列分子标记在系统分类应用中的不足.对于藻类鉴定,单纯依赖分子标记或形态学都不足以保证鉴定的准确性,采用将分子生物学、形态学、生理生化学等结合的多相学方法,才能准确地完成鉴定工作.此外,藻类分子数据库的建立和完善是未来分子鉴定的重要工作,快速鉴定方法也必将在未来获得广泛的应用和发展.  相似文献   

12.
13.
At the beginning of August 1997, 72 samples of flood sediments were taken along the Upper and Middle Odra river and its tributaries. The concentrations of Zn, Pb, Cu, Cd, Co, Ni, Cr, Mn, and Fe in the bulk samples and in the <20 μm fraction were determined by AAS method. The contents of metals vary in wide ranges and are significantly higher in the <20 μm fraction of sediments. The range concentrations vary as following: Zn 274...3 656 mg/kg, Pb 79...1 773 mg/kg, Cd 1.7...11.8 mg/kg, Cu 38...2 244 mg/kg, Cr 14...384 mg/kg, Co 4...73 mg/kg, Hg 0.2...3.9 mg/kg, Mn 214...6 972 mg/kg, and Fe 1.5...16.3 %. The highest amount of the metals was found in the Wrocław and Głogów regions. The mobile (exchangeable and carbonatic fractions) portions of metals reached up to 50 % of Zn, 40 % of Pb and Cu and 60 % of Mn.  相似文献   

14.
Abstract Fossil otariid pinnipeds of the extinct genera Prototaria Takeyama and Ozawa, 1984, and Neotherium Kellogg, 1931, known from Middle Miocene deposits bordering the North Pacific Ocean, are small, primitive pinnipeds in the subfamily Imagotariinae. They have a small supraorbital process of the frontal or have lost it entirely, a three-rooted first molar, small paroccipital process, and ear morphology indicating that they belong in the subfamily Imagotariinae. Their unique derived characters include extreme intertemporal constriction and highly modified cheek teeth, the premolars having become molarized by the addition of protocones and lingual cingula. Prototaria Takeyama and Ozawa, 1984, the most primitive known imagotariine genus, contains two species, P. primigena Takeyama and Ozawa, 1984, and P. planicephala Kohno, 1994, both of early Middle Miocene age from Japan. Prototaria has a few derived characters, including a large antorbital process, narrow intertemporal region, and large orbit, but its primitive characters apparently were inherited from enaliarctine ancestors. The long enigmatic Neotherium mirum Kellogg, 1931, of Middle Miocene age from California, USA, is related to Prototaria, but differs by having an elongate skull, very slender zygomatic arch, ventrally exposed median lacerate foramen, and smaller but more molarized premolars. A more primitive new genus and species, Proneotherium repenningi Barnes, related to N. mirum, is from the early Middle Miocene Astoria Formation, coastal Oregon, USA. It shares some derived characters with Prototaria, and shares many other important derived characters with N. mirum. Imagotariines probably arose from some species of Early Miocene enaliarctines, became diverse in Middle and Late Miocene time, and are only known from the North Pacific realm. Although they might include the ancestors of true walruses of the subfamily Odobeninae, no known imagotariines appear to have been adapted for mollusk feeding as are the highly evolved modern walruses. Instead, imagotariines appear to have retained a primitive piscivorous diet, as did the fur seals and sea lions of the subfamily Otariinae.  相似文献   

15.
The aims of this study were to evaluate levels and effects of trace metals (Cd, Cr, Cu, Fe, Mn, Pb, Zn), PAHs and PCBs in mussels and fish native to the Lagoon of Venice. To this end, bioaccumulation and various biomarkers of generic stress and exposure (malondialdehyde, MDA and metallothioneins, MT; ethoxyresorufin O-deethylase activity, EROD; fluorescent bile metabolites and somatic indices in fish; lysosomal membrane stability, LMS; lipofuscins, LF; neutral lipids, NL and survival-in-air, SOS in mussels) were measured in organisms seasonally collected from two differently influenced areas. In mussels, metal bioaccumulation levels at the two sites were low and fluctuated similarly, exhibiting decreasing levels in summer, like MDA and MT. Micro-organic pollutants and the probably related biological response of LMS did not show either significant site differences or seasonal trends. LF and NL revealed inconclusive patterns. The results of the survival-in-air test were quite erratic, showing that they were associated with the high variability of both natural and physiological parameters temperature, food, reproduction, and body reserve cycle. In fish, both inorganic and organic micropollutant levels were low, and differences were detected between sites only for PCBs. The pattern exhibited by micro-organic contaminants was clearly related to the reproductive cycle at both sites; a relationship with PCBs, EROD and MDA was established at the site where their levels were generally higher. Bile metabolites (3-OH benzo(a)pyrene, 1-OH pyrene) were associated with PAH contents.  相似文献   

16.
A geographic information system (GIS)-based chemometric approach was applied to investigate the spatial distribution patterns of heavy metals in marine sediments and to identify spatial human impacts on global and local scales. Twelve metals (Zn, V, Ni, Mn, Pb, Cu, Cd, Ba, Hg, Fe, Cr and Al) were surveyed twice annually at 59 sites in Hong Kong from 1998 to 2004. Cluster analysis classified the entire coastal area into three areas on a global scale, representing different pollution levels. Backward discriminant analysis, with 84.5% correct assignments, identified Zn, Pb, Cu, Cd, V, and Fe as significant variables affecting spatial variation on a local scale. Enrichment factors indicated that Cu, Cr, and Zn were derived from human impacts while Al, Ba, Mn, V and Fe originated from rock weathering. Principal component analysis further subdivided human impacts and their affected areas in each area, explaining 87%, 84% and 87% of the total variances, respectively. The primary anthropogenic sources in the three areas were (i) anti-fouling paint and domestic sewage; (ii) surface runoff, wastewater, vehicle emissions and marine transportation; and (iii) ship repainting, dental clinics, electronic/chemical industries and leaded fuel, respectively. Moreover, GIS-based spatial analysis facilitated chemometric methods.  相似文献   

17.
The hierarchically organized laminae, bundles, bundlesets and superbundlesets which correspond to a sub-Milankovitch, obliquity or precession, eccentricity and long eccentricity cyclothems, respectively, have been distinguished from the Upper Devonian Fras-nian-Famennian (F-F) transitional carbonate successions deposited in the carbonate-basin and slope facies of Guangxi, South China. The durations of cyclothems are 8000-10000a, 16667a or 33333a, 100000a and 400000a, respectively. The ratio of eccentricity to precession, eccentricity to obliquity, and long eccentricity to eccentricity is 1 : 6, 1 : 3 and 1 : 4 in the Devonian, respectively. Orbital cyclostratigraphical studies show that the durations of the conodont falsio-valis Zone, transitans Zone, punctate Zone, Lower hassi Zone, Upper hassi Zone, jamieae Zone, Lower rhenana Zone, Upper rhenana Zone, linguiformis Zone, Lower triangularis Zone, Middle triangularis Zone and Upper triangularis Zone are 0.4, 0.4, 0.4, 0.3, 0.4, 0.2, 0.8, 0.6, 0.8, 0.3, 0  相似文献   

18.
The most important geomorphic responses to storms are qualitative changes in system state. Minor storms produce no state change or very rapid recovery to pre‐storm state, and extinction events wipe out the system. In other cases disturbance results in a state change, which may be transitional (change to a previously existing state), state space expansion (change to a new state), and clock‐resetting events that return the system to its initial state. Recovery pathways are much more varied than the monotonic progressions represented in classic vegetation succession and linear channel evolution models. Those linear sequential pathways are only one of several archetypal recovery pathways, which also include binary, convergent, divergent, and more complex networks. Filter‐dominated systems are more likely to follow linear sequential or convergent patterns, whereas amplifier‐dominance is characteristic of divergent and more complex mesh or fully‐connected patterns. Amplifier domination is also more likely to lead to evolutionary or state space expansion responses. Amplification and filtering in geomorphic response and recovery can be assessed using the 'Four R's' framework of response, resistance, relaxation, and recursion. High resistance and resilience, rapid relaxation times, and stable recursive feedback networks reduce or offset effects of disturbances, thus filtering their impacts. Conversely, low resistance and resilience, slow relaxation, and dynamically unstable feedbacks can exaggerate disturbances, creating disproportionately large and long‐lived impacts, thereby amplifying disturbances. Unless new filter mechanisms evolve (either autogenically or anthropically), or the number of extinction or clock‐resetting events increases, intensified storminess will result in more geomorphic variability. These ideas are applied to a case study of a flood on the Clark Fork River, Montana, USA. Copyright © 2016 John Wiley & Sons, Ltd.  相似文献   

19.
A large groundwater system in the Amadeus Basin, central Australia, discharges to a chain of playa lakes 500 km long. The playas contain highly concentrated brines; these are sodium-chloride rich waters with appreciable magnesium and sulphate and very low concentrations of calcium and bicarbonate. Gypsum, glauberite, and other evaporite minerals are precipitating in the playas. The groundwaters evolve to brine by concurrent processes of dissolution, evaporative concentration, mineral precipitation, and mineralogical change. Chemical evolution is considered with reference to a concentration factor based on chloride. Ion transfer calculations demonstrate losses of magnesium and bicarbonate throughout, as a result of precipitation. Sodium, potassium, calcium, and sulphate are gained initially as a result of dissolution but lost subsequently as a result of precipitation. Larger playas in the chain, exemplified by Lake Amadeus, have dual shallow and deep groundwater flow paths whereas the smaller playas, exemplified by Spring Lake, have only shallow flow paths. Brines in the larger playas are diluted by deep groundwaters and this is reflected in the degree of saturation attained with respect to particular minerals. Thus, saturation with respect to gypsum and glauberite is attained earlier in Spring Lake than in Lake Amadeus. Saturation with respect to halite is attained in Spring Lake but not in Lake Amadeus. Both playas are undersaturated with respect to hexahydrite and sylvite although these minerals occur in efflorescent crusts in Spring Lake.  相似文献   

20.
宋丹  李林 《地震工程学报》2019,41(6):1671-1678
为避免震后建筑工程加固不合理导致再次受损,并为加固修复工程提供合理化建议,促进震后救灾工作顺利开展,提出震后建筑工程混凝土缺陷加固修复方法的研究。首先,对混凝土梁试件和混凝土柱试件进行设置,研究基于碳纤维布或外包钢套加固方法对混凝土梁和混凝土柱试件展开循环荷载试验;其次,通过混凝土梁试件滞回曲线、骨架曲线、延性及耗能情况,分析不同加固修复方法的混凝土梁试件抗震性能;最后,通过混凝土柱试件延性及耗能、刚度退化和承载力退化情况,分析采用不同加固方法修复的混凝土柱试件抗震性能。试验结果显示:高配筋率可提升混凝土梁试件滞回特性,外包钢套加固混凝土梁试件滞回饱满程度较高、耗能较少,碳纤维布加固梁试件可将加载位移由10 mm延缓至30 mm,提升延性;碳纤维布加固可提升混凝土柱延性,外包钢套加固重度缺陷混凝土柱可以良好抑制其刚度和承载力退化。试验结果验证了碳纤维加固可提升震后建筑工程混凝土结构延性,外包钢套加固可抑制混凝土结构刚度、承载力退化。  相似文献   

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