上海地震台阵与台网的定位及视慢度研究   总被引：3，自引：1，他引：3  

任隽  朱元清  潘纪顺  陈运平 《地震研究》2002,25(4):335-340

阐述了台阵的地震定位原理和视慢度在台阵与台网定位中的一些重要特性，并比较了相同位置上的上海地震台阵与台网对同一地震的定位结果。最后，对上海台队与台网导致定位误差的横向速度变化的位置和范围给出了矢量校正的结果并进行了初步讨论。  相似文献   

An analysis of phytolith assemblages for the quantitativereconstruction of late Quaternary environments of the Lower Taieri Plain,Otago, South Island, New Zealand II. Paleoenvironmentalreconstruction     

Matiu Prebble  James Shulmeister 《Journal of Paleolimnology》2002,27(4):415-427

Fossil phytolith assemblages from a 154.5 m longdrillcore from the Lower Taieri Plain, Otago, New Zealand are presented. Transferfunctions, based on modern phytolith assemblages from sites within the sameregion, were applied to the fossil phytolith data set, and validated usingModern Analogue Technique (MAT) assemblage matching. Analogues for much of theHolocene and some of the Last Interglacial (provisionally Oxygen Isotope Stage5c) were obtained. Late Glacial/Holocene precipitation and pH estimates areconsistent with other paleoclimate records from the Otago region. Thephytolith-based precipitation and pH estimates may act as a combined proxy forsoil weathering. The precipitation estimates may also act as a useful index ofEffective Precipitation (EP). Temperature estimates derived have limited usefor paleoclimate interpretation. Estimates produced for the mid-Holoceneindicate a wetter environment than the present (50–100 mmgreater EP) with increased soil weathering (high precipitation/low pH). Soilconductivity estimates were below estuarine levels during a diatom inferredmarine transgression. This lack of phytolith response to conductivity changesis put down to a probable delayed development of suitable habitats forsaltmarsh plant species during the rapid transgression. The Last Interglacialestimates indicate conditions somewhat drier (200 mm less EP) thanthe Holocene. Consistently low log conductivity (below 0.7 µScm) estimates from the Last Interglacial contrast with the estuarineenvironments of the Holocene, indicating freshwater conditions in the Plainduring at least part of the Last Interglaciation.  相似文献   

Statistical analysis of modern seed assemblages from the San Francisco Bay: applications for the reconstruction of paleo-salinity and paleo-tidal inundation     

Michelle Goman 《Journal of Paleolimnology》2001,26(4):393-409

The feasibility of developing a seed calibration data set to infer environmental constraints was examined by studying modern seed and vegetation assemblages from 53 stations at three distinct tidal marshes within the San Francisco Bay (salt, brackish and freshwater). Pearson's correlation indicates autochthonous derivation of seeds at the marsh sites. Multivariate statistical analysis of the vegetation and seed data indicates discrete assemblages, which can be used as a proxy for modern salinity and tidal inundation within the estuary. Canonical discriminant analysis indicates that the vegetation and seed assemblages of the three marsh types are statistically distinct. Cluster analysis suggests that marsh vegetation is zoned at the mean higher high water mark at all the sites. The calibration set was then applied to stratigraphic seed data from the estuary to infer changes in paleo-salinity and -tidal inundation during the Holocene. The results of the calibration are compared to earlier reconstructions within the estuary. While the calibrated reconstruction broadly compares to previous reconstructions, a period of inferred lower salinity within the estuary between 3800–2000 cal yr B.P. is calibrated as brackish and not fresh by the calibration model.  相似文献   

CONSTRAINED BACKGROUND BILINEARIZATION WITH A GENERALIZED SIMULATED ANNEALING ALGORITHM     

YULONG XIE  JIHONG WANG  YIZENG LIANG  KAI GE  RUQIN YU Department of Chemistry  Chemical Engineering  Hunan University  Changsh  People''s Republic of China 《地理学报(英文版)》1993,(5)

Generalized simulated annealing(GSA)is an optimization technique for locating the global optimum.Inthis paper GSA was used as the optimization procedure in the constrained background bilinearization(CBBL)of two-way bilinear data in order to reduce the possibility of sinking into local optima.Thebehaviour of the algorithm and its comparison with the modified Powell algorithm were studied bysimulations and real fluorescence excitation-emission data for organic dye mixtures.  相似文献   

COMPUTER-GENERATED MULTICOMPONENT CALIBRATION DESIGNS FOR OPTIMAL ANALYSIS SAMPLE PREDICTIONS     

KIMBERLY HITCHCOCK  JOHN H.KALIVAS  JON M.SUTTER 《地理学报(英文版)》1992,(2)

This paper utilizes variable step size generalized simulated annealing(VSGSA)to design multicomponentcalibration samples for spectroscopic data.VSGSA is an optimization procedure which is capable ofconverging to exact positions of global optima located on multidimensional continuous functions.On thebasis of analysis sample response vectors,optimally designed calibration concentration matrices areobtained assuming knowledge of components present.The complexity of response surfaces establishedby the optimization criteria is described.  相似文献   

论中国地震台网测得的面波震级   总被引：2，自引：0，他引：2       下载免费PDF全文

陈培善  叶文华 《地球物理学报》1987,30(1):39-51

文中使用了一个新的量规函数σ₃₀₀（Δ）,它是基于面波传播理论,考虑了面波的几何扩散、非弹性吸收、频散衰减以及面波优势周期随震中距的变化导出的,取全球平均Q=300。在震中距Δ=20°-160°的范围内与IASPEI推荐的面波震级的量规函数σ_IASPEI（Δ）一致,又推广了σ_IASPEI（Δ）的震中距使用范围,从1.0°-179°,以及可使用的面波周期范围（7.5-30s）,因此它更适合我国由中周期宽频带SK仪组成的台网情况。若采用此量规函数σ₃₀₀（Δ）和进行方位角改正,则可使我国台网测出的M_s与国际地震中心（ISC）测出的一致,震级误差降到0.19级,此误差与苏联台网的误差一样。  相似文献   

水汞观测中值得注意的几个问题   总被引：1，自引：0，他引：1  

王振升 《地震》1996,16(3):311-317

通过实际工作和实验研究认为：（１）水汞观测室温１５－３０℃，湿度在８０％以上是最佳工作条件。当气温在３１℃以上，湿度连续超过８０％，则仪器零点漂移大，捕汞管净化困难，标定Ｋ值减小。即使在干燥季节，测室温度在１２℃以下，可使标定Ｋ值变大；（２）实验表明硫酸含汞，有的高，有的低， 启用应作选择。氯化亚锡对汞量测定影响不大，选择杂质少，溶液清亮，释汞能力强的；（３）蒸馏水经常更换也有一定干扰；（４）外拉  相似文献   

山西地震台网震级偏差与震中距关系的讨论     

孟雁英  侯廷爱 《山西地震》1996,(3):33-36

统计分析了山西省地震台网观测报告测震震级的现状。发现单台震级偏离台网平均震级较大，讨论了这些值偏大的原因，指出这是原始量规函数的地区差异及系统偏差所致，提出求算适合山西地区高精度量规函数的建议  相似文献   

用于裂变径迹技术刻度的铀标准玻璃的研制     

赵云龙  翟鹏济 《铀矿地质》1997,13(2):117-121

监测中子积分通量是裂变径迹技术的重要组成部分。铀玻璃监测中子积分通量是国际裂变径迹定年标准化工作组推荐的重要方法之一，铀玻璃测定法还普遍用于测定样品中的铀含量及其空间分布。本文介绍的铀标准玻璃，经过多家实验室定值测定，表明其稳定性、均匀性均达到国家一级标准物质的要求，抗酸性能达到Ⅰ级光学玻璃水平，抗潮性能达到Ⅱ级光学玻璃水平。其它性能指标均达到或超过美国国家标准局的同类产品。  相似文献   

Exploring the possibilities for star-tracker assisted calibration of the six individual GOCE accelerometers   总被引：1，自引：0，他引：1  

P. N. A. M. Visser 《Journal of Geodesy》2008,82(10):591-600

A method has been developed and tested for estimating calibration parameters for the six accelerometers on board the Gravity field and steady-state Ocean Circulation Explorer (GOCE) from star tracker observations. These six accelerometers are part of the gradiometer, which is the prime instrument on board GOCE. It will be shown that by taking appropriate combinations of observations collected by the accelerometers, by modeling acceleration terms caused by gravity gradients from an a priori low-degree spherical harmonic expansion, and by modeling rotational acceleration terms derived from star-tracker observations, scale factors of each of the accelerometers can be estimated for each axis. Simulated observations from a so-called end-to-end simulator were used to test the method. This end-to-end simulator includes a detailed model of the GOCE satellite, its instruments and instrument errors, and its environment. Results of the tests indicate that scale factors of all six accelerometers can be determined with an accuracy of around 0.01 for all components on a daily basis.  相似文献