南极中山站固体潮观测分析

中国南极中山站位于南极拉斯曼丘陵地区（λ＝７６°２２′Ｅ，φ＝６９°２２′Ｓ），１９９１年３月至１９９３年２月，用ＬａｃｏｓｔｅＥＴ型重力仪，在这个地区进行了为期近两年的观测，取得了６００多天的有效资料，经调和分析和流变模型、海潮负荷改正后得到：δｏ１＝１．２２５３±０．００３１，Δφｏ１＝０．７３°±０．１４°；δｍ２＝１．０７８５±０．００４５，Δφｍ２＝－３．５５°±０．２９°从资料分析的精度来看，观测资料是比较好的；但由于海潮负荷改正缺少附近海域的资料，会对最终结果造成较大的影响     

地幔滞弹性对Chandler摆动的影响

基于简正模扰动理论和勒夫数扰动方法,采用Zschau 的地幔流变模型,在假设Chandler摆动的能量全部耗散于地幔滞弹性摩擦的条件下,导出Chandler 摆动Q(Q_w)的理论值.还考虑了滞弹地球的平衡极潮对摆动的影响,所得结果与绝大部分天文实测值非常一致.分析表明.平衡部分的影响大,地幔滞弹性很可能是Chandler 摆动最主要的能量耗散源,Q_w 的理论值约为71.还推算了吸收带模型参数α,研究了该模型的适用性,并讨论了Q_w 与地幔Q(Q_m)的关系.     

乌鲁木齐重力潮汐研究与震兆异常

利用Ｖｅｎｅｄｉｋｏｖ调和分析法分析了乌鲁木齐ＧＳ－１５－２１６重力仪１９９０～１９９３年的潮汐记录，得到了该地区的重力潮汐参量：δｏ１＝１．１５８２６±０．０００４９，Δｏ１＝０．１５±０．０２，δＭ２＝１．１６１０８±０．０００２２，ΔＭ２＝－０．３２±０．０１。主波Ｍ２和Ｏ１的结果与１９８０年中比协作时ＧＥＯ－０８４的观测结果一致，与Ｍｏｌｏｄｅｎｓｋｙ模型１值符合很好。不同时段得到的δ值和Δ值内符合精度高，表明乌鲁木齐地区重力场稳定，重力仪性能稳定，观测资料可用于检验地球模型、研究地球深部构造以及震源物理场。分析了和静东北两次５．２级地震前δＭ２值的短期前兆异常，确认从目前的重力潮汐观测中可以分辨出变化量大于１％的δ因子震兆异常．     

北京重力地球潮参数和重力仪力学特性的测定

根据北京白家疃测站８台ＧＥＯ潮汐重力仪对比观测的资料，采用标准线性体流变模型模拟重力仪及记录系统的力学特性，计算各台仪器的格值改正系数、主潮汐波的振幅衰减系数和相位滞后；确定北京重力地球潮的振幅因子δ和相让滞后为δ（Ｍ_２）＝１．１７８４，δ（Ｏ_１）＝１．１８０４，δ（Ｍ_２）／δ（Ｏ_１）＝０．９９８３，（Ｍ_２）＝０．０７°，（Ｏ_１）＝０．１０°．     

EUTROPHICATION AND RED TIDES AS CONSEQUENCES OF ECONOMIC DEVELOPMENT

1 mTRoorcnoxThe EnvirDment AgenCy of UK (l997) defins eUtIDPhication as "the enrichInnt of waters byinorgedc plant nUtrientS that result in the simulation of an mp Of syInPtOInati changes. These includethe inCrased PrOduCtiOn Of aigae or othe aquatic PlantS, affeChng the quallty of the water and distUIbingthe balance Of orpedsms Present within it. Such changes Inay be undesirable and intetw with wateuses." Sndth et al. (l999) indicated tha eopation of waters is mainly caused by h…     

新疆新源台固体潮潮汐因子特征浅析

采用Venedikov调和分析方法对新源台倾斜固体潮整点观测数据进行处理，得到倾斜固体潮鸩波潮汐因子变化曲线。分析其震兆异常特征，给出了新源台倾斜固体潮潮汐因子异常标准，结果发现异常与周围200km范围内的5级以上地震对应较好，具有较高的预报效能并通过了尺值评分检验。     

Improving the accuracy of tipping-bucket rain records using disaggregation techniques

We present a methodology able to infer the influence of rainfall measurement errors on the reliability of extreme rainfall statistics. We especially focus on systematic mechanical errors affecting the most popular rain intensity measurement instrument, namely the tipping-bucket rain-gauge (TBR). Such uncertainty strongly depends on the measured rainfall intensity (RI) with systematic underestimation of high RIs, leading to a biased estimation of extreme rain rates statistics. Furthermore, since intense rain-rates are usually recorded over short intervals in time, any possible correction strongly depends on the time resolution of the recorded data sets. We propose a simple procedure for the correction of low resolution data series after disaggregation at a suitable scale, so that the assessment of the influence of systematic errors on rainfall statistics become possible. The disaggregation procedure is applied to a 40-year long rain-depth dataset recorded at hourly resolution by using the IRP (Iterated Random Pulse) algorithm. A set of extreme statistics, commonly used in urban hydrology practice, have been extracted from simulated data and compared with the ones obtained after direct correction of a 12-year high resolution (1 min) RI series. In particular, the depth–duration–frequency curves derived from the original and corrected data sets have been compared in order to quantify the impact of non-corrected rain intensity measurements on design rainfall and the related statistical parameters. Preliminary results suggest that the IRP model, due to its skill in reproducing extreme rainfall intensities at fine resolution in time, is well suited in supporting rainfall intensity correction techniques.     

Determination of vertical displacements over the coastal area of Korea due to the ocean tide loading using GPS observations

This paper describes the GPS applicability for detecting the vertical displacements of ground stations caused by ocean tide loading effects. An experiment was carried out using 12 permanent GPS stations located in the coastal area of Korea using data in the period 1 July until 26 August 2003. The relative height differences were calculated from hourly DGPS data processing based on the carrier-phase observation. The power spectra of the M₂ and N₂ constituents of ocean tide loading were derived using the CLEAN algorithm. The differential vertical displacements generated by the ocean tide loading effect are typically 3–25 mm in coastal area of the Korea. We compared the results from GPS with those of the ocean tide models, NAO.99Jb regional model and GOT00.2, FES99 global models. The M₂ (N₂) amplitude differences of vertical displacements between GPS and GOT00.2 is 1.22 ± 3.61 mm (1.01 ± 1.48 mm), and that of the M₂ (N₂) amplitude difference between GPS and FES99 is 0.04 ± 4.64 mm (0.64 ± 1.75 mm), whereas the M₂ (N₂) amplitude difference between GPS and NAO.99Jb are 0.05 ± 1.03 mm (0.86 ± 1.18 mm). The highest vertical displacements at the PALM station are found for 24.5 ± 0.7 mm from GPS observation, and 22.9 mm from the regional model NAO.99Jb and 13.17 and 10.00 mm from the global models GOT00.2 and FES99, respectively. These values show that the vertical displacements derived from GPS are in good agreement with those of the regional model NAO.99Jb around Korea, more than with the global models. This result indicated that GPS is an effective tool to measure the vertical displacement caused by the ocean tide loading effect in the coastal area, and we need to use the NAO.99Jb ocean tide model rather than the global ocean tide models in and around the Korean peninsula for position determination with permanent GPS installations. This work demonstrates that vertical displacement caused by the M₂ and N₂ constituents of ocean tide loading can be measured by carrier-phase DGPS.     

由井-含水层系统的水位动态反演含水层体应变

以孔隙弹性理论和水文地质学原理为基础,给出井水位波动与含水层介质体应变变化关系的数学表达式,结合固体潮理论分析了井—含水层系统水位潮汐波动对体应变固体潮的响应特征,用水位潮汐波来反演含水层体应变的变化,将反演结果与体应变实测资料得到的结果进行对比,发现二者有较好的一致性,说明用水位潮汐波来反演含水层体应变的方法是可行的,它为了解含水层的水文地质特性、体应变的变化及探索地震前兆提供了借鉴。     

A non‐baseline algorithm for damage locating in flexural structures using dynamic distributed macro‐strain responses

The concept of distributed strain‐sensing techniques has been proposed in our recent research, which was dedicated to utilizing the strain distributions throughout the full or partial areas of structures to detect arbitrary and unforeseen damage. An algorithm not requiring a detailed analytical model is presented for damage locating in flexural structures through the direct use of dynamic responses recorded by distributed long‐gauge strain sensors. The modal macro‐strain vector (MMSV), which has been proven to have a mapping relation with displacement mode shape, can be extracted directly from macro‐strain time‐series data, from which a damage evaluating index can be derived and used as an indicator for locating damage. Numerical examples are simulated to verify the sensitivity and effectiveness of the index in different cases. Furthermore, experimental investigations on a cantilevered beam with various long‐gauge fibre optic sensors placements are carried out to examine the feasibility and applicability of the proposed method. Copyright © 2007 John Wiley & Sons, Ltd.