利用小波变换方法分析跨断层形变异常   总被引：16，自引：8，他引：8  

李杰  李明海  刘希强  张京华  郑树田  范军 《大地测量与地球动力学》2004,24(3):73-78

为了从跨断层形变观测资料中获取中强地震的前兆异常信息，运用二进小波变换方法和噪声与信号的定量识别方法，分析了不同尺度的小波变换的细节信号变化特征。研究结果表明：(1)不同尺度小波变换分解的细节信号显示出不同的时变特征。当尺度为1时。细节信号主要为噪声；尺度为2、4、5时，细节信号主要为非平稳信号；尺度为3时，细节信号主要为平稳周期信号；(2)每月观测一次的跨断层形变资料在尺度为3时的细节信号有较好的年周期特征；(3)当尺度为3时的细节信号变化超出2倍均方误差时，测点周围200km左右范围内发生中强地震的可能性很大。  相似文献   

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李延兴  徐杰  张静华  郭良迁  张中伏 《大地测量与地球动力学》2007,27(6):1-8

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基于GIS的区域医疗卫生状况分析与评价     

张帅毅  徐京华 《测绘通报》2011,(3):75-77

应用GIS空间分析功能对相关医疗卫生状况进行空间数据挖掘,构建区域医疗卫生状况评价模型,量化区域医疗卫生状况指标,并生成分析与评价结果图,以辅助决策分析.  相似文献   

A numerical investigation of the impacts of anthropogenic sulfate aerosol on regional climate in East Asia     

Jinghua Chen  Yan Yin  Hui Xiao  Qian Chen 《Asia-Pacific Journal of Atmospheric Sciences》2014,50(3):391-403

Aerosol and its effects, especially its indirect effects, on climate have drawn more and more attention in recent years. In this study, the first indirect radiative forcing (RF) of sulfate aerosol and its impacts on the regional climate in East Asia during the period from December 2008 to November 2009 were investigated. Affected by the general circulation and the conversion efficiency from SO₂ to SO₄ ^2? in aqueous phase, a remarkable seasonal variation of sulfate was found. The results show that the highest sulfate concentration as large as 24 g m^?2 appears in the summer. The indirect RF due to sulfate aerosol at the top of atmosphere (TOA) and the surface is negative, which leads to a cooling effect on the surface by 0.12°C and a reduction of precipitation by 0.01 mm d^?1. The tendencies of temperature and rainfall have significant diversity in space and time. The cloud feedback, associated with the hydrologic cycle and energy budget, is responsible for this discordant distribution. The variation of low cloud dominates the change of surface temperature. The subsidence due to the cooling effect in the mid atmosphere restrained and reduced the low clouds, leading to an apparent warm effect on the surface in Northeast Mongolia.  相似文献   

南海及周围地区的现今构造运动   总被引：1，自引：0，他引：1  

李延兴  张静华  周伟  栾锡武  胡新康  张中伏 《大地测量与地球动力学》2010,30(3)

利用南海及其周围地区的GPS数据,分析南海及周围地区速度场和应变场的空间变化,以及相邻块体之间的相对运动.研究发现,南海现今仍在继续扩张,西部是从其北边缘向南沿NW-SE方向逐渐扩张的,东部是从中心向北与向南逐渐扩张的.由主张应变率计算的中央海盆近SN方向的平均扩张速率为3.1 mm/a.在南海东部(117.0°E),南北之间(11°～22°N)SN方向的扩张速率为9.3 mm/a,小于65Ma以来NNW-SSE方向13.0 mm/a的平均扩张速率.南海的扩张运动是印度板块、太平洋和菲律宾海板块与欧亚板块之间的相互作用,以及南海地区地幔物质上涌共同作用的结果.  相似文献   

Effects of dietary menadione on the activity of antioxidant enzymes in abalone, Haliotis discus hannai Ino     

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A 240-day growth experiment in a re-circulating water system was conducted to investigate the effects of dietary menadione on the growth and antioxidant responses of abalone Haliotis discus hannai Ino. Triplicate groups of juvenile abalone (initial weight: 1.19 ± 0.01 g; shell length: 19.23 ± 0.01 mm) were fed to satiation with 3 semi-purified diets containing 0, 10, and 1 000 mg menadione sodium bisulfite (MSB)/kg, respectively. Results show that there were no significant differences in the rate of weight gain or in the daily increment in shell length of abalone among different treatments. Activities of superoxide dismutase (SOD), glutathione peroxidase (GPX), glutathione S-transferase (GST) and glutathione reductase (GR) in viscera were significantly decreased with dietary menadione. However, activities of these enzymes except for GPX in muscle were increased. Therefore, antioxidant responses of abalone were increased in muscle and decreased in viscera by dietary menadione.  相似文献   

利用MODIS/EVI数据分析干旱对西南地区植被的影响(英文)   总被引：2，自引：0，他引：2  

张景华  姜鲁光  封志明  李鹏 《资源与生态学报(英文版)》2012,3(1):43-49

2009年9月至2010年3月我国西南地区出现了有气象记录以来最严重的干旱,给当地的自然环境和生产、生活带来严重影响。本文利用多年MODIS/EVI数据求取距平植被指数来反映干旱对西南地区植被的影响。在此基础上,分析了西南地区植被受旱的时空格局及其可能影响因素。结果表明,我国西南地区植被受干旱影响的范围很大,超过地区总面积的50%,植被受旱程度时空差异显著。这种显著的差异除了受降水等气象因素影响外,还与不同植被类型对干旱的响应差异有很大关系。在西南地区三种主要的植被类型中,作物是最易受干旱影响的植被类型,草地次之,林地的抗旱能力最强。此外,植被干旱的空间分布与气象干旱也存在很大的差异,进一步证明了降水以外的其他因素对干旱程度的调节作用。研究证明与气象干旱指数相比,植被指数更能反映干旱的实际情况。但在使用植被指数衡量干旱影响时也要考虑到植被指数本身的局限性。  相似文献   

华南块体的现今构造运动与内部形变   总被引：16，自引：7，他引：9  

张静华  李延兴  郭良迁  张中伏 《大地测量与地球动力学》2005,25(3):57-62

运用华南块体及周围地区最新的GPS观测结果,研究了华南块体的现今构造运动。华南块体无论是相对于欧亚板块或相对于西伯利亚块体都存在逆时针方向的旋转。由GPS观测结果得到的华南块体相对于西伯利亚块体的现今旋转运动与由地质学和地球物理学方法得到的自晚新生代以来华南块体相对于西伯利亚的旋转运动相比,运动速率相同,但运动方向顺时针旋转了20.7°。  相似文献   

The chemistry of heavy haze over Urumqi,Central Asia   总被引：1，自引：0，他引：1  

Juan Li  Guoshun Zhuang  Kan Huang  Yanfen Lin  Qiongzhen Wang  Yuhong Guo  Jinghua Guo  Shulong Yu  Caixia Cui  Joshua S. Fu 《Journal of Atmospheric Chemistry》2008,61(1):57-72

A sampling campaign of aerosols over Urumqi from 2001–2007 and soil samples in the surrounding areas were carried out to investigate the severe air pollution in Urumqi, a typical inland city, located in the center of Asia. Urumqi is one of the heavy polluted cities in the world, as the days of haze spanned over one third of the year and accounted for 60–80% of the heating period for the past 6 years. High concentration of fine aerosols, frequent occurrence, and rapid formation of heavy haze were the three main characteristics. With comparison of the pollution elements, As, Cd, and S, and the ratio of Ca/Al in aerosols and soils in those sites located on the south of Jungger Basin as tracers, it was found that As, Cd, and S highly enriched in the aerosols over urban Urumqi were not only from the re-suspended road dust but also from the soil transported from south of the Jungger Basin. Different from the most cities in China, the high concentration of sulfate in Urumqi was partially from the primary soil dust transported from the surrounding areas. The mixing of the local anthropogenic aerosols with the soil transported from outside the city was the main source of the high sulfate concentration. Ammonium salts were higher than the summed equivalents of SO₄²⁻, NO₃⁻, and Cl⁻ in Urumqi and much higher than that in other Chinese cities. The total water soluble ions and the total ammonium salts were as high as 57.8% and 51.0% in PM_2.5. The high concentration of soluble salts with high hygroscopicity, especially ammonium and sulfate salts, were the main factors contributing to the heavy haze over Urumqi.  相似文献   

云南省前兆模拟观测数据库系统的设计及实现   总被引：4，自引：4，他引：0  

李倩  任勇  牛从达  山秀明  武孔春  段洪杰  马兢华  安小伟 《地震研究》2004,27(3):287-292

介绍了云南省前兆模拟观测数据库系统。该系统由前兆模拟观测数据库和数据库管理软件两部分组成。针对云南省前兆模拟观测手段多、时段长、覆盖面广等特点,选用Microsoft SQ LServer 2000为数据库平台设计建立了云南省前兆模拟观测数据库;针对前兆观测方法及台站观测手段分类管理的特点,选用Delphi为开发工具编制了前兆数据库管理软件。该系统的实现解决了分析预报和研究人员对长期积累的前兆观测数据的科研需要。  相似文献