金州断裂降震效应初探

利用位于金州断裂两侧地震台所记录的地震震级的差异,研究金州断裂的降震效应。统计表明,当地震波通过断裂时存在明显的衰减现象,震级相差近０．４级。     

Distribution Characteristics of Pollutants and Their Mutual Influence in Highway Runoff

Many environmental pollution issues from highway runoff increasingly become a serious concern, which has been revealed by many previous studies. However, very less information is available on the distribution characteristics of pollutants and their mutual influence in highway runoff. In this paper, the partitioning of pollutant and particle size distribution were investigated based on the initial road runoff of 47 rainfall events from July 2007 to May 2009 on the Lukou section of the Nanjing Airport Expressway, China. This study is emphasizing on the analysis of the mutual impact of pollutant distribution and the relationship between particle size and pollutant distribution. The impact of rainfall characteristics, water temperature, and pH values in runoff samples on the pollutant distribution was also studied. Result shows that partitioning of different pollutants was varying significantly. Volume of particles in different sizes was different, with the highest volume of particles of 21–75 µm size. The distribution of COD highly affected the distribution of TN, and somewhat promoted the distribution of Pb in particles. TP, Pb, and Cd promoted distribution of each other's in particles. There was better competition among Zn, Cu, and Cd, when heavy metals combined with particles. The particles ranged between 21 and 75 µm size had an obvious impact on the distribution of COD, Pb, and TN in the particulate matter. TP in the particulate matter mainly distributed in particles ranged in 151–300 µm size. Rainfall duration significantly affected the Pb in particulate matter. The distribution of Zn in the particulate matter mostly was affected by pH values.     

基于人口统计数据的区域震害快速评估方法

在进行大规模城乡震害预测工作中, 需要使用与传统预测方式不同的新模型及新方法, 以便实现震害快速预测. 利用容易得到的人口统计数据中的人口及建筑抽样信息,通过建筑物分类,在已有的城市建筑震害基础上采用类比方法进行建筑物易损性分析,给出了人口数据及灾害损失的关系模型. 利用该模型建立福建省区域范围的建筑物不同结构平均易损性矩阵,按经济条件给出结构不同年代易损性矩阵调整系数,并建立地震灾害快速评估系统. 应用结果表明, 基于人口统计数据方法进行城乡区域尺度的地震震害评估模型, 具有投入少、 数据自动预测、定期更新且易于获取等优点.      

Shallow velocity structure and hidden faults of Kunming city region

In order to image the 3-D velocity structure of its shallow crust in Kunming region,China,finite-difference seis-mic tomography is used to invert the seismic data selected carefully from six-shot data. The result lays a founda-tion for the discussion of the relationship between the obtained velocity structure and the hidden faults,and for the illumination of the depth extents of main active faults surrounding Kunming city. Puduhe-Xishan fault lies on the western margin of the Kunming basin and is just situated on the west edge of the low velocity anomaly zone found at all depth levels. This indicates that this fault is a borderline fault of the Kunming basin. It can be concluded that the fault dips eastwards with a steep angle and its depth extent is large. Puji-Hanjiacun fault and Heilong-tan-Guandu fault play a role in controlling the low velocity anomaly zone in middle basin. The depth extents of the two faults are comparatively small,without traversing the interface of basin floor.     

大渡河流域梯级水电站场地地震影响特征研究

本文利用四川地区及邻区的烈度衰减关系式,计算了历史强震对大渡河梯级水电站场址的影响烈度和最大烈度。同时,还分析了水电站场址在历史强震发生密集时的地震影响烈度特征,以期为今后梯级水电站的地震安全综合防御和地震应急工作提供参考。     

震后短期和长期形变模拟——以1960年智利Mw9.5地震为例

以1960年5月智利瓦尔迪维亚(Valdivia)Mw9.5地震为例分析震后不同时期的形变,实现了以Burgers体为粘弹介质模型来模拟震后粘弹松弛效应有限元数值模拟.计算结果表明,该粘弹介质模型可以模拟地震引起的瞬时同震弹性响应及震后粘弹松弛的短期和长期响应.由1960智利Mw9.5地震震后模拟的应变率显示以Burgers体为粘弹介质模型可以解决Maxwell体在模拟震后短期和长期形变不协调问题.     

An integrated East China Sea–Changjiang Estuary model system with aim at resolving multi-scale regional–shelf–estuarine dynamics

A high-resolution numerical model system is essential to resolve multi-scale coastal ocean dynamics. So a multi-scale unstructured grid-based finite-volume coastal ocean model (FVCOM) system has been established for the East China Sea and Changjiang Estuary (ECS–CE) with the aim at resolving coastal ocean dynamics and understanding different physical processes. The modeling system consists of a three-domain-nested weather research and forecasting model, FVCOM model with the inclusion of FVCOM surface wave model in order to understand the wave–current interactions. The ECS–CE system contains three different scale models: a shelf-scale model for the East China Sea, an estuarine-scale model for the Changjiang Estuary and adjacent region, and a fine-scale model for the deep waterway regions. These three FVCOM-based models guarantee the conservation of mass and momentum transferring from outer domain to inner domain using the one-way common-grid nesting procedure. The model system has been validated using data from various observation data, including surface wind, tides, currents, salinity, and wave to accurately reveal the multi-scale dynamics of the East China Sea and Changjiang Estuary. This modeling system has been demonstrated via application to the seasonal variations of Changjiang diluted water and the bottom saltwater intrusion in the North Passage, and it shows strong potential for estuarine and coastal ocean dynamics and operational forecasting.     

汶川MS8.0地震前云南地区显著前兆观测异常分析

汶川M_S8.0地震前云南地区出现了显著的前兆观测异常. 该文从大地震的孕育范围出发分析认为这些地震前兆异常可能与汶川M_S8.0地震有关, 并认识到前兆观测出现的显著极值异常可能是M_S≥7.0大地震的前兆; 有学者认为大震震源区没有或较少出现前兆观测趋势异常是大地震的共性特征, 汶川M_S8.0地震的前兆观测异常也是相同的; 地震前兆观测异常开始和结束时间是多样的, 前兆异常的分布是复杂的, 因此利用震后总结的共性特征, 在震前对汶川M_S8.0地震作出预测是困难的.      

Shape and position of Earth’s bow shock near-lunar orbit based on ARTEMIS data

Earth’s bow shock is the result of interaction between the supersonic solar wind and Earth’s magnetopause. However, data limitations mean the model of the shape and position of the bow shock are based largely on near-Earth satellite data. The model of the bow shock in the distant magnetotail and other factors that affect the bow shock, such as the interplanetary magnetic field (IMF) B_y, remain unclear. Here, based on the bow shock crossings of ARTEMIS from January 2011 to January 2015, new coefficients of the tail-flaring angle α of the Chao model (one of the most accurate models currently available) were obtained by fitting data from the middle-distance magnetotail (near-lunar orbit, geocentric distance -20R_E>X>-50R_E). In addition, the effects of the IMF B_y on the flaring angle α were analyzed. Our results showed that: (1) the new fitting coefficients of the Chao model in the middle-distance magnetotail are more consistent with the observed results; (2) the tail-flaring angle α of the bow shock increases as the absolute value of the IMF B_y increases. Moreover, positive IMF B_y has a greater effect than negative IMF B_y on flaring angle. These results provide a reference for bow shock modeling that includes the IMF B_y.     

Sources and transport of nitrate constrained by the isotopic technique in a karst catchment: an example from Southwest China

The concentration and isotopic composition of nitrate were analyzed to improve an understanding of nitrate sources and transformation processes in a typical karstic agricultural field in the Houzhai catchment, Guizhou Province, Southwest China. The results revealed that no distinct spatial pattern of content and isotopic composition of nitrate exists in this karst catchment. Nitrate in surface stream (SFS) had slightly lighter isotopic composition and lower concentration compared with nitrate in subterranean stream (STS) during the dry season. Concentrations of SFS nitrate increased to concentrations similar to those of STS during the wet season. The isotopic values indicated that nitrate were mainly impacted by manure sources during the dry season and influenced by a mix of chemical fertilizer and manure during the wet season. The denitrification rates were roughly estimated based on the isotopic compositions of nitrate after considering volatilization and ignoring assimilation. The calculated result showed that approximately one fifth of nitrate load was removed by denitrification in the catchment. Annual nitrate flux from the outlets accounted for 14.2% of applied total fertilizers used in the catchment, approximately 85% of total transported flux from the catchment in the wet season. Furthermore, chemical weathering processes were enhanced by using nitrogen fertilizer because liberated protons and enhanced HCO₃^? flux were produced through by nitrification. Copyright © 2014 John Wiley & Sons, Ltd.