利用小波变换方法识别山西形变异常信息     

荆红亮  张仰辉  李艳  冯建琴  李军 《山西地震》2011,(2):6-9

文章主要根据小波变换方法在不同尺度时细节的变化特征,通过一些震例对山西数字形变资料进行分析研究,发现,经过小波变换处理后的数据在细节部分达到第5层、第6层时,震前资料会显示出比较同步的长周期信号,这为识别和提取数字洞体形变资料中的趋势异常和短期异常提供了新的探索思路和方法。  相似文献   

导航电子地图生产过程中的质量控制方法     

李瑞月  肖成才  朱婧  马威  李宏利 《测绘软科学研究》2011,(5):42-45,70

从分析导航电子地图数据特点和质量特性入手,给出导航电子地图生产过程中从检测标准、质控设置、检验手段到质量改进的质量控制过程。  相似文献   

高重复率SLR数据预处理方法的实现     

张忠萍  张海峰  高皓  瞿锋 《测绘科学》2011,36(3):172-173,24

千次重复频率SLR技术主要优势是观测数据量犬,从而得到高精度测量结果,相比低重复频率(小于10Hz)测距资料,kHz数据量有近百倍的增加,因而快速、有效对每次每圈卫星kHz资料处理是高重复率激光测距重要内容,以满足ILRS对测距数据及时处理和发送的要求.通过采用均匀选取数据的点图方式,加速数据点屏幕显示;采用Visua...  相似文献   

卡尔曼滤波算法的灰色理论模型在变形监测中的应用   总被引：4，自引：0，他引：4  

姜刚  杨志强  张贵钢 《测绘科学》2011,36(4):19-21

本文针对灰色理论模型在建模过程中受到随机扰动影响这一问题,提出了利用卡尔曼滤波处理建模数据的方法.经过实例检验,证明基于滤波算法的灰色理论模型在一定程度上可以提高预测值的精度,更好地反映了观测目标的变形趋势,在变形监测中具有一定的优势.  相似文献   

积水沉陷区水体的表观光学特性参数测量与分析     

朱继文  孟祥来  张贺 《地理空间信息》2011,9(3):6-8

通过实际测量试验区的积水沉陷区水深值,了解水体光学特性随水深不同而引起的衰减特征变化,建立水深与光谱特性响应间的关系表达式,确定获取水深信息的最佳波谱范围;揭示了叶绿素、悬浮物质、CDOM等水体组分与水体光谱特征变化的关系,探讨因水体各主要组分变化而引起的水体光谱吸收光谱、散射光谱的变化规律.  相似文献   

1955—2007年拉萨市雨季夜雨率变化特征   总被引：1，自引：0，他引：1  

余忠水 《气象》2011,37(12):1584-1588

利用1955—2007年拉萨市逐日降水和气温地面观测资料,分析了拉萨市雨季（5—9月）夜雨率变化特征。结果表明：拉萨市整个雨季日夜雨率变化是比较稳定的,近50多年来基本没有发生明显的年代际变化。夜雨率与日降水量有显著关联,当日降水量在25 mm以下时,夜雨率随降水量增加而增大,当日降水量〈1 mm时夜雨率最小为75.2%,当日降水量为25 mm时,夜雨率达到最大值93.4%;夜雨率与日温差存在显著的负相关;拉萨多夜雨与地形有关,高夜雨率既有有利的一面,也会带来一些负面影响。因此,深入探讨夜雨率是制定有效防御气象灾害对策的重要依据。  相似文献   

Analysis of the Trends of Thunderstorms in 1951–2007 in Jiangsu Province   总被引：2，自引：1，他引：1  

魏建苏  刘梅  张备  俞剑蔚 《热带气象学报(英文版)》2011,17(1):58-63

Based on the 1951–2007 thunderstorms in Jiangsu, a study is conducted for their climate trends, periodicity, spatiotemporal patterns, and the distributions of the first and last days of the thunderstorms at different guarantee rates (GRs) using climate tendency rate, wavelet analysis, and GR for diagnosis. Results suggest that the inter-annual number of thunderstorm days (TSDs) exhibits a decreasing trend in this province. The trend is displayed mainly in the decreasing TSD number in summer and autumn except in spring, when the variation is not significant in the study period. In this province, the TSD number declines by ~2 days per 10 years. On an inter-annual basis, the pronounced positive departures of the number take place chiefly in the early 1960s, the late 1960s to the early-mid-1970s, the late 1980s, and the late 1990s compared with the negative anomalies dominant in the late 1970s to the mid-1980s, the mid-to-late-1990s, and the late 1990s to 2007. There are vast differences in the initial and ending days at diverse GRs in different areas of the province. At 50% GR, the earliest (last) days occur from mid-March to early April (early to late September) while at 80% GR, the initial (last) days are from late March to early May (early to late October). For the distribution of periods, the periods >8–10 years are relatively stable for the entire province. Based on 1951–2007 period analysis, the region north (south) of the Huaihe River experiences TSDs less (more) than normal days in recent years.  相似文献   

石灰土中秸秆还田降解率及其对土壤肥力的影响   总被引：1，自引：0，他引：1  

黄芬  韦红群  曹建华 《资源与生态学报(英文版)》2015,(4)

石灰土具有高的有机碳的积累,但营养成分的供给速率偏低,导致土壤贫瘠。本文通过室内模拟实验,研究相同来源玉米秸秆在岩溶土与非岩溶土中的降解情况,对秸秆降解率、土壤理化性质、土壤肥力等进行动态检测,结果表明：（1）总体上岩溶土秸秆降解速率比非岩溶土快。秸秆降解速度最快主要集中在最初60天,之后呈缓慢上升趋势,到98天基本达到平衡。非岩溶土降解峰值出现时间为第42天,岩溶土为第28天,峰值出现时间前者比后者滞后14天。总降解时间持续160天,岩溶土降解率为77%,非岩溶土为75%。（2）秸秆降解期间,土壤pH值前期有下降的趋势,后期慢慢回升,这与秸秆降解过程中不同时期降解产物变化规律相吻合。秸秆还田可以提高土壤肥力,其中速效氮和速效钾含量增加非常明显。（3）与岩溶土相比,全量检测结果显示各肥力指标在非岩溶土含量低,但升幅百分比高;有效态检测结果显示非岩溶土速效磷和速效钾含量高。说明秸秆还田一些营养元素有效态在非岩溶土中更易于释放,而岩溶土由于其土壤质地的特殊性,许多养分被土壤粘土矿物牢固结合,营养元素供给速率慢,但因此也易于养分全量的累积。  相似文献   

Low calcification rates and calcium carbonate production in Porites panamensis at its northernmost geographic distribution          下载免费PDF全文

Carlos Orión Norzagaray‐López  Luis Eduardo Calderon‐Aguilera  José Martín Hernández‐Ayón  Héctor Reyes‐Bonilla  Juan P. Carricart‐Ganivet  Rafael Andrés Cabral‐Tena  Eduardo Francisco Balart 《Marine Ecology》2015,36(4):1244-1255

Porites panamensis is a hermatypic coral present in the eastern Pacific Ocean. Skeletal growth parameters have been reported, but studies of the relationship between annual calcification rates and environmental controls are scarce. In this study, we investigated three aspects of the annual calcification rates of P. panamensis: growth parameters among three P. panamensis populations; the sea surface temperature as a calcification rate control spanning a latitudinal gradient; and calcium carbonate production among three sites. Growth parameters varied among the sites due to the colony growth form. Massive colonies in the north showed a higher calcification rate than encrusting colonies in the south (mean: 1.22–0.49 g CaCO₃ · cm^?2 · yr^?1), where variations in calcification rates were related to growth rate (0.91–0.38 cm · yr^?1) rather than to skeletal density differences (overall mean ± SD, 1.31 ± 0.04 g CaCO₃ · cm^?3). Our results showed a positive linear relationship between annual calcification rates and sea surface temperatures within these P. panamensis populations. Differences were related to distinct oceanographic environments (within and at the entrance of the Gulf of California) with different sea surface temperature regimes and other chemical properties. Different populations calcified under different environmental conditions. Calcium carbonate production was dependent upon the calcification rate and coral cover and so carbonate production was higher in the north (coral cover 12%) than in the south (coral cover 3.5). Thus, the studied sites showed low calcium carbonate production (0.25–0.43 kg CaCO₃ · m^?2 · yr^?1). Our results showed reduced calcification rates, regional temperature regime control over calcification rates, different growth forms, low coral cover and low calcium carbonate production rates in P. panamensis.  相似文献   

不同光照周期对刺参摄食节律和消化生理的影响     

孙佳敏  王芳  张立斌  林承刚  杨红生  阚仁涛 《海洋科学》2015,39(5):1-8

在实验室条件下,研究了全光照(24L︰0D)、半光照半黑暗(12L︰12D)、全黑暗(0L︰24D)3种光照周期下刺参(Apostichopus japonicus)的摄食节律、摄食率以及3种消化酶(脂肪酶、淀粉酶、胰蛋白酶)活力的昼夜变化规律。结果显示:(1)在全光照条件下,刺参极少活动,24 h内的摄食比例较低(6%~10%);在半光照半黑暗条件下,刺参光照阶段运动不活跃,摄食比例较低(0~10%),黑暗阶段运动极其活跃,摄食比例较高;在全黑暗条件下,刺参一直处于较活跃状态,24 h内的摄食比例都较高。3种光照条件下,刺参的摄食高峰都出现在00:00~02:00,且刺参夜晚的摄食比例显著高于白天(P0.05);(2)刺参的日摄食率从全光照、半光照半黑暗到全黑暗依次增加,3种光照周期条件下刺参夜晚的摄食率极显著高于白天的摄食率(P0.01);(3)3种光照周期下,刺参3种消化酶活力的最大值都出现在22:00~02:00,消化酶活力的最大值比摄食高峰早0~4 h。研究结果表明,光照对刺参的摄食节律和消化酶活力昼夜变化都有显著影响,刺参具有提前分泌消化酶为即将到来的摄食做好准备的调节机制。  相似文献