南海季风爆发的统计动力分析

作者对南海季风爆发作了统计动力分析,即将南海季风爆发前后的高低层风场看成一个整体,并以南海季风爆发日为基准,对风场作了经验正交函数(EOF)分析,得到了以下结论:偏差风场的第一模态反映了高低层东亚夏季风环流在南海季风爆发日前后有剧烈变化,这直接体现了南海季风的爆发,并表明此时大气环流有突变发生;第二、三模态则分别反映了具有5～7天振荡周期的中高纬大气长波活动和亚洲季风区中准双周低频振荡的主要活动区,以及中低纬度大气环流的相互作用;第二模态体现了偏差风场的幅散风部分而第三模态则体现了旋转风部分.     

结构双层多重调谐质量阻尼器(DMTMD)控制策略的鲁棒性评价

基于定义的二类优化目标函数,评价双层多重调谐质量阻尼器(DMTMD)控制策略对漂移频率系数(DFR)摄动的鲁棒性。数值研究表明,使用第二类优化准则设计的DMTMD、双重调谐质量阻尼器(DTMD)和多重调谐质量阻尼器(MTMD)比使用第一类优化准则设计的DMTMD、DTMD和MTMD具有更高的对DFR摄动的鲁棒性。而且,使用第二类优化准则设计的总数为4的DMTMD、DTMD和总数为11的MTMD具有近似相同的对DFR摄动的鲁棒性。     

Using Kolmogorov-Smirnov Statistics to Compare Geostrophic Velocities Measured by the Jason,TOPEX, and Poseidon Altimeters

The Kolmogorov-Smirnov (K-S) test is used to compare probability density functions (PDFs) of geostrophic velocities measured by the TOPEX, Poseidon, and Jason altimeters. Velocity PDFs are computed in 2.5° by 2.5° boxes for regions equatorward of 60° latitude. Although velocities measured by the TOPEX and Jason altimeters can differ, on the basis of the K-S test the velocities are statistically equivalent during the ～200 day period when the satellites followed the same orbit. Full records from TOPEX, Poseidon, and Jason show less agreement, which can be attributed to temporal variability in ocean surface velocities and differing levels of measurement noise.     

LDPC码及其研究进展

对低密度奇偶校验码(LDPC)的结构、编译码原理进行了介绍，并与turbo码进行了简单的比较，最后对目前LDPC码的几个研究方向及其进展作了较详细的论述，指出LDPC码具有很大的发展前景。     

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???ú??CORS?????????4???GPS????????????GAMIT/GLOBK??????е??????????????????????????????????????????????????????????????????????????3???????????????150 mm??11?′??????????4??????????????????10 mm/a????????溯?????????????????????????????????6′×6′?????????????????????????????????     

纳入政府目标考核 建立有效工作机制——合肥市加强和创新防震减灾社会管理的有益尝试

介绍了合肥市创新防震减灾社会管理机制的基本做法,分析了其成效与不足,提出了进一步加强市县防震减灾社会管理的意见和建议。     

锚杆挡土墙可靠度分析与计算方法

提出了锚杆挡墙中肋柱锚杆体系的串-并联模型。将肋柱视为连续梁,锚杆视为弹性支座,引入锚杆与锚固段周围岩土体的复合刚度系数,用位移法导出了各根锚杆所受荷载的统一计算公式。考虑各功能函数之间的相关性,运用系统可靠性理论,提出了单根锚杆3种破坏模式的串联系统与多根锚杆并联系统的体系可靠度计算方法,并编制了计算程序。对一工程实例进行计算,并对计算结果进行了分析,发现单根锚杆的3种失效模式并非相互独立,每种失效模式对锚杆可靠度的影响也不一样,而3根锚杆并联系统的失效概率近似等于在其他锚杆均未破坏的条件下每根锚杆单独失效概率之和。     

Does a one point sample adequately characterize the lake environment for paleoenvironmental calibration studies?

A major goal of paleolimnological studies is the quantification of past environmental conditions. This is accomplished by computing transfer functions relating organism assemblages to environmental factors. The environmental data are typically comprised of a point sample of water chemistry and other environmental parameters that are collected at the same time as a surface sediment sample. We explore whether the year of sampling of the environmental variables affects the parameterization of organism-environment relations, in particular chironomids, ostracodes and diatoms. Canonical correspondence analyses revealed that the year of sampling is of secondary importance when relating the organism assemblages to environmental variables, but only with the major explanatory variables. A chironomid-inferred bottom water temperature partial least squares transfer function revealed similar performance statistics between the years. Taxon optima and tolerances were computed for both years using weighted averaging, and the results are comparable. A paired t-test computed on the proxy-inferred bottom water temperature values indicated that the results between the 2 years are not statistically different. The results of this study provide guarded optimism that the methodology of estimating transfer functions as currently applied is not entirely determined by the particular year when the data were collected, although more case studies are needed.     

地电场信号去噪小波函数的选取

介绍了小波函数的基本性质,并根据密山地电场数据的特征选取适合密山地电场数据去噪的的小波族函数,最后综合去噪结果和误差分析结果选出适合密山地电场数据去噪的最优小波函数和最佳分解层数。     

Modern diatom assemblages from Chilean tidal marshes and their application for quantifying deformation during past great earthquakes

Tidal marsh sediments from south‐central Chile provide evidence for multiple great earthquakes. Diatom transfer functions, statistical models of the relationship between species preserved in the sediment and elevation, provide quantitative estimates of coseismic vertical land‐level change associated with individual earthquakes. However, in south‐central Chile, our ability to quantify land‐level change is currently limited by a lack of understanding of the environmental variables controlling the distribution of diatoms, an essential prerequisite for converting variations in fossil diatom assemblages into quantitative estimates of past elevation changes. We present a new modern diatom dataset for the region and explore the implications of the scale of the dataset used in transfer function models on the reconstructions of land‐level change. Modern training sets containing samples from a regional scale are superior to sub‐regional and local‐scale training sets, providing closer estimates for known deformation during the great 1960 Chilean earthquake, a higher proportion of good modern analogues and uncertainty terms up to 42% smaller than previously published reconstructions. Copyright © 2017 The Authors. Journal of Quaternary Science Published by John Wiley & Sons Ltd.