Regionally Representative Ozone Monitoring at Cape Arkona     

R. Dubois  H. Flentje  F. Heintz  H. J. Karbach  U. Platt 《Journal of Atmospheric Chemistry》1997,28(1-3):97-109

Long Path Different Optical Absorption measurements of theconcentrations of O₃, NO₂, NO₃ andSO₂ were carried out at Cape Arkona, Island Rügen, nearthe well-known long-term ozone registration. A statistical analysis ofdifferent trace gas concentrations for all seasons is presented. Daytimedata, wind speed and sector-classified results are used to estimaterepresentative ozone concentrations. Comparison of the long path ozonemeasurements with point measurements at Cape Arkona shows ozoneconcentration differences.  相似文献   

强烈地震前的OLR异常现象   总被引：54，自引：1，他引：54  

刘德富  罗灼礼 《地震》1997,17(2):126-132

利用卫星遥感地图射出长波辐射（ＯＬＲ）资料，分析我国１９７６～１９８５年在龙陵，唐山，松潘，乌恰，共和等５个地区发生的７级以上的大地震前的ＯＬＲ异常现象，发现强震发生地区，在时间上和空间上，震前一个月都存在为显著的热红外辐射异常，如果这种“热前兆”异常是可靠的，可能开拓出一种强震短期预报的新方法。  相似文献   

纬向风与赤道异常的行星波同步振荡及其谱分析     

罗毅  陈培仁 《地球物理学报》1993,36(6):717-724

本文利用最大熵谱分析方法处理了电离层赤道异常北峰Okinawa站的f₀F₂行星波周期的振荡.比较同一期间相近经度链上的南北半球观测到的低热层中性大气运动,发现较短周期的2-5日波,尤其是在南北半球的夏季期间（北半球7-8月前后,南半球1-2月前后）,其纬向风与赤道异常振荡强弱及周期变化具有良好的同步对应性.对于较长周期的中性风振荡,只要其幅度相当大,也会在赤道异常的振荡中有所对应.从而提供证据说明中性风的行星波振荡是赤道异常的行星波振荡的驱动源.  相似文献   

Constraints On the Seismotectonics of the Central Mediterranean From Very Long Baseline Interferometry   总被引：6，自引：0，他引：6  

Steven N. Ward 《Geophysical Journal International》1994,117(2):441-452

  相似文献   

陆-气耦合的长周期波动     

李超  汤懋苍 《高原气象》1989,(2)

本文从大气中的热量平衡和陆地下垫面的热传导方程出发,探讨陆-气耦合作用。发现在这耦合系统中存在两类长周期波动:一类是周期约为4—9个月的准半年波;另一类是周期为2—5年的准三年波。重点讨论了准三年波的振荡特性。  相似文献   

Shaking hazard compatible methodology for probabilistic assessment of permanent ground displacement across earthquake faults   总被引：2，自引：0，他引：2  

M.I. Todorovska  M.D. Trifunac  V.W. Lee 《Soil Dynamics and Earthquake Engineering》2007,27(6):586-597

A methodology for probabilistic hazard assessment of permanent displacement across faults caused by earthquake rupture is presented, compatible with region specific models for ground shaking hazard in California, developed earlier by the authors and coworkers. Assessment of permanent dislocations across faults is important for the design and retrofit of highway bridges and tunnels crossing faults, as well as for other lifelines crossing faults, such as aqueducts, water and gas lines, etc. The methodology is illustrated for two strike-slip faults (prototypes of Class A and Class B faults in California), for 50 years exposure. The illustrations show that, for given seismic moment rate, the hazard estimates are quite sensitive to how the seismic moment is distributed over earthquake magnitudes. They also show that the hazard is small even for very small levels of displacement, in contrast to ground shaking hazard, which is due to the fact that only one fault contributes to the hazard and not every event on that fault necessarily affects the site.  相似文献   

The International VLBI Service for Geodesy and Astrometry (IVS): current capabilities and future prospects     

Wolfgang Schlüter  Dirk Behrend 《Journal of Geodesy》2007,81(6-8):379-387

Very Long Baseline Interferometry (VLBI) plays a unique and fundamental role in the maintenance of the global (terrestrial and celestial) reference frames, which are required for precise positioning in many research areas such as the understanding and monitoring of global changes, and for space missions. The International VLBI Service for Geodesy and Astrometry (IVS) coordinates the global VLBI components and resources on an international basis. The service is tasked by the International Association of Geodesy (IAG) and International Astronomical Union (IAU) to provide products for the realization of the Celestial Reference Frame (CRF) through the positions of quasars, to deliver products for the maintenance of the terrestrial reference frame (TRF), such as station positions and their changes with time, and to generate products describing the rotation and orientation of the Earth. In particular, VLBI uniquely provides direct observations of nutation parameters and of the time difference UT1-UTC. This paper summarizes the evolution and current status of the IVS. It points out the activities to improve further on the product quality to meet future service requirements.  相似文献   

路堑边坡平面滑动演化过程及远程滑动机制的模拟与分析     

王浩  孙木子  马新凯  廖小平  林一夫  吴志刚 《工程地质学报》2015,23(3):438-447

永宁高速公路K117滑坡路段原为在泥质粉砂岩单斜地层内开挖2级形成的路堑边坡,开挖后产生典型平面滑动,在中部滑床形成长约25m的滑动槽,产生最远达35m的远程滑距,其成因机制复杂。本文在对滑坡基本特征及孕育过程开展详细调查研究的基础上,采用节理有限单元法对该滑坡经路堑开挖导致高位坍滑、刷方变更后触发高速远程滑塌、滑塌后壁残留滑体牵引松动,以及对其实施卸载、支挡回填及锚固的治理过程开展数值模拟,再现了该滑坡孕育发展全过程及其稳定性演化规律;分析了该边坡破坏的平面滑动机构及滑动面的物理力学特征,论述了该类滑坡启动高速远程滑动的开挖松弛致滑机理和裂隙充水致滑机理,最后提出了预测及治理该类滑坡的6点建议。研究表明,在单斜地层开挖路堑,使顺倾向软弱结构面临空暴露时,可能诱发边坡整体卸荷松弛,产生较大的不平衡滑坡推力,而卸荷松动产生的张裂隙导致滑坡对降雨入渗十分敏感,不平衡力和裂隙水压力的共同作用可迅速剪断滑面,伴随势能向动能的转化,产生高速远程滑动。  相似文献   

共沉淀法制备SrAl2O4：Eu^2＋，Dy^3＋发光材料及其性能表征          下载免费PDF全文

刘美英  龙光明  祁米香  王舒娅 《盐湖研究》2009,17(2):50-56

研究了在液相共沉淀法制备长余辉发光粉体SrAl2O4∶Eu2+,Dy3+的过程中,原料锶铝比、煅烧温度、保温时间对前躯体和煅烧产物的物相组成以及产物的长余辉性能的影响。采用X射线粉晶衍射仪(XRD)、荧光材料余辉特性测试仪对发光材料的物相组成和性能进行测试表征。研究表明,液相共沉淀法制备长余辉发光粉体SrAl2O4∶Eu2+,Dy3+的最佳条件为锶铝量比为1∶2,烧结温度1200℃及保温时间为3h;长余辉材料的物相组成以SrAl2O4相为主晶相,并存在富铝相Sr4Al14O25、SrAl4O7和SrAl12O19。  相似文献   

Holocene paleoclimate changes determined using diatom assemblages from Lake Long,King George Island,Antarctica     

Kyung Lee  Sook-Kyung Yoon  Ho Il Yoon 《Journal of Paleolimnology》2009,42(1):1-10

Formation of Lake Long, King George Island, Antarctica started about 4,000 years B.P., after which the diatom community changed in response to environmental shifts driven by climatic oscillations (warm/wet and cool/dry). Successive sequences of diatoms in a 7.5-m drill core were divided into 11 assemblage zones by cluster analysis. The most obvious change was an alternation of major dominants, Achnanthes minutissima, Fragilaria alpestris and Fragilaria pinnata v. antarctica according to the climatic oscillations in the late Holocene. Variations in diatom assemblages clearly reflect two warm periods, a single cool period, and three transition periods. The recent warm period (zones 2 and 1) has persisted for approximately 450 years, perhaps sufficiently long to suggest the imminent onset of a new transition period. A recent high TOC (total organic carbon) value in the core reflects a warm period in Antarctica during the late Holocene.  相似文献