Elastic reverse time migration based on vector wavefield decomposition

Prestack elastic reverse time migration ( RTM) requires multicomponent seismic data .But for multi-component elastic Kirchhoff migration , there is a limitation that ray theory no longer applies if thegeology be-comes complicated .In this paper, the authors have created a new 2D migration context for isotropic , elastic RTM, which included decomposition of the elastic source and receiver wavefields into P and S wave vectors by decoupled elastodynamic extrapolation , which retained the same stress and particle velocity components as the input data .Then we appliedsource-normalized crosscorrelation imaging condition in elastic reverse time migra-tion to compensate the energy of deep strata .We found that the resulting images were nearly identical to the ve-locity model , and the resolution has been improved .Our method is a wavefielddecomposition based on vector , and we can alsoavoid the problem of polarity reversal of converted shear wave imaging .It proved the applicabili-ty of the method proposed in our paper .     

Bench–shelf system dynamic characteristics and their effects on equipment and contents

Economic losses during past earthquakes are strongly associated with damage and failure to nonstructural equipment and contents. Among the vast types of nonstructural elements, one important category, is scientific equipment in biological or chemical laboratories. These equipment are often mounted on heavy ceramic bench‐tops of bench–shelf systems, which in turn may amplify the dynamic motions imposed. To investigate the seismic response of these types of systems, a series of shake table and field experiments were conducted considering different representative bench and shelf‐mounted equipment and contents. Results from shake table experiments indicate that these equipment are generally sliding‐dominated. In addition, the bench–shelf system is observed to be very stiff and when lightly loaded, has a fundamental frequency between 10 and 16 Hz. An approximate 50% reduction in the first and second fundamental frequencies is observed considering practical loading conditions. Insight into a broader range of system response is provided by conducting eigenvalue and time history analyses. Non‐linear regression through the numerical data indicate acceleration amplification ratios Ω range from 2.6 to 1.4 and from 4.3 to 1.6, for fixed–fixed and pinned–pinned conditions, respectively. Both the experimental and numerical results support the importance of determining the potential dynamic amplification of motion in the context of accurately determining the maximum sliding displacement of support equipment and contents. Copyright © 2006 John Wiley & Sons, Ltd.     

PROPERTIES OF PROTEOLYTIC TOXIN OF VIBRIO ANGUILLARUM FROM DISEASED FLOUNDER

Extracellular products(ECP)produced by Vibrio anguillarum strain M3 originally isolated from diseased flounder(Paralichthys olivaceus)were prepared.ECP of M3 showed gelatinase,casinase,amylase and haemolytic activity on agarose plates.High protease activity against azocasin was detected.Bacterium M3 showed highest growth and protease activity at 25℃。The Protease present in ECP showed maximal activity at pH 8 and 55℃；was completely inactivated by application of 80℃ heat for 30 min;was completely inhibited by EDTA and HgCl2,and was partially inhibited by PMSF,SDS,MnCl2 and iodoacetic acid;but not inhibited by CaCl2 and MgCl2.The ECP was toxic to flounder fish at LD50 values of 3.1 μg protein/g body weight.The addition of HgCl2 and application of heat at 50℃ decreased the lethal toxicity of ECP.When heated at 100℃,ECP lethality to flounder was completely in-hibited.After intramuscular injection of ECP into flounder,it showed evident histopathological changes including necrosis of muscle,extensive deposition of haemosiderin in the spleen,dilated bolld vessels congested with numerous lymphocytes in the liver.These results showed that ECP protease was a lethal factor produced by the baterium V.anguillarum M3.     

大定源瞬变电磁均匀层状介质正演计算

大定源回线瞬变电磁法以其高效的工作方式,一直备受野外工作者青睐。这里从基本理论出发,给出了大定源回线发射源在均匀层状介质的电磁响应计算公式,利用Quadrature With Extrapolation(QWE)算法计算了线框内、外的垂向磁场响应,并将其与传统的Fast Hankel Transform(FHT)算法进行了对比分析,两者对于虚部的计算都比较准确。当发射线框位于地表以上一定高度时,两者的计算结果吻合的较好。在发射线圈位于地表的时候,QWE算法的计算结果比较稳定,适用性优于FHT。     

低解吸气量页岩气组分校正方法探讨

通过现场解吸试验,采用气相色谱等测试方法,对低解吸气量页岩气组分测定结果校正方法进行了研究。在常规现场解吸试验操作基础上增加校正实验,结合理想气体状态方程,总结归纳出校正参数及适用性研究。结果显示,当解析气量较少时,解吸罐内残留空气对组分测定结果的影响较大,排除解吸罐中空气的影响后,解吸气组分甲烷体积分数普遍增加12.23%~54.44%。研究表明,对低解吸气量页岩气组分结果进行校正十分必要。     

论地体综合构造热演化-试以青藏为例

作者在论述地体绘合构造热演化研究的意义和论证构造演化和热演化之间存在着成因联系的基础上，结合青藏工作实际，系统地阐述了:(1)在构造热演化模型设计中必须遵循概全性与概略性相结合的原则;模型因子应是概全的，但模拟的方法则是简略的;(2)以构造演化为框架、以热演化为本构的研究方法。文中列出了包括放射性生热(Q_r，地体应变生热(Q_s)，断层摩擦生热(Q_f) .岩石圈底熔减薄增热(Q_b)等多元热源项在内的二维昨稳态热传导一平流方程，作为应用有限差分与有限单元相结合方法求解宏观地质区构造热演化课题的通用方程。     

Response to orthogonal components of ground motion and assessment of percentage combination rules

The effects of horizontal components of ground motion on the linear response of torsionally stiff and torsionally flexible systems, on soft and firm soil conditions, are examined. A one‐story, two‐way asymmetric structural system is used, subjected to uncorrelated ground motion components along their principal directions. Spectral densities for ground accelerations in firm and soft soils are modeled based on recorded data from large intensity Mexican earthquakes. It is shown that for firm soils, in general, these effects are important in the case of torsionally flexible systems that are stiff under translation, or for torsionally stiff systems that are flexible in translation. The percentage combination rules usually specified in seismic design codes are assessed against the dynamic response. Such combination rules can result in overly conservative design forces or underestimated design forces, particularly for torsionally flexible structures. Given the relative magnitude of the response to each ground motion component, it was found that using different percentage values in the combination rules has no significant effect on improving the estimation of the total response. Copyright © 2003 John Wiley & Sons, Ltd.     

施氮时期对‘马瑟兰’葡萄果实芳香物质组分与含量的影响

采用顶空固相微萃取技术（HS-SPME）、气相色谱-质谱联用技术（GC-MS）对‘马瑟兰’葡萄果实中芳香物质成分进行分析,分别在萌芽期、新梢旺长期、开花期、果实第1次膨大期、副梢旺长期和果实第二次膨大期一次性施入氮肥,以不施氮肥作为对照（CK）,研究不同施氮时期对果实芳香物质组分及含量的影响。结果表明：‘马瑟兰’葡萄果实中共检测出40种芳香物质成分,总含量为1 789.49—3 320.29 μg·kg^-1,其中有11种特征香气成分,以醇类和醛类化合物为主,氮素施用时期对果实芳香物质的成分和含量均有显著的影响;施氮可改变果实的香味特征,果实第二次膨大期施氮果实中芳香物质总含量最高且种类较多,有利于提高醇类、醛类及烷烃类化合物含量;该处理改变了果实以草香味为主的香味特征,此时花香和脂膏香最为浓郁;开花期施氮果实中草香、脂膏香和花香基本平衡,同时增加了果香味的比例。通过氮素施用时期可调控葡萄果实芳香物质的形成,进而改善果实的酿造品质。     

An example of cluster analysis applied to a large geologic data set: Aerial radiometric data from Copper Mountain, Wyoming

One objective of the aerial radiometric surveys flown as part of the U.S. Department of Energy's National Uranium Resource Evaluation (NURE) program was to ascertain the spatial distribution of near-surface radioelement abundances on a regional scale. Some method for identifying groups of observations with similar -ray spectral signatures and radioelement concentration values was therefore required. It is shown in this paper that cluster analysis can identify such groups with or without a priori knowledge of the geology of an area. An approach that combines principal components analysis with convergentk-means cluster analysis is used to classify 6991 observations (each observation comprising three radiometric variables) from the Precambrian rocks of the Copper Mountain, Wyoming area. This method is compared with a convergentk-means analysis that utilizes available geologic knowledge. Both methods identify four clusters. Three of the clusters represent background values for the Precambrian rocks of the area, and the fourth represents outliers (anomalously high²¹⁴Bi). A segmentation of the data corresponding to geologic reality as interpreted by other methods has been achieved by perceptive quantitative analysis of aerial radiometric data. The techniques employed are composites of classical clustering methods designed to handle the special problems presented by large data sets.     

基于组件式WebGIS的统计专题图的实现

采用RIA主流的Flex技术平台Flex Builder作为网页设计载体,利用其技术优势结合组件式WebGIS—MapGIS IGServer组件功能,阐述基于组件式WebGIS的统计专题图的设计原理与思路,以福建省统计年鉴的历年统计数据为例,设计并实现一个在线发布统计数据、生成结合地图的统计专题图站点,方便用户利用客户端交互操作获取更加直观的统计数据及相关统计图表,可为统计机构在改进网站功能和统计数据的发布方式时提供新的思路。