Multistep matched-field inversion for broad-band data from ASIAEX2001

This paper discusses the results of geoacoustic inversion carried out using explosive charge data from the Asian Seas International Acoustic Experiment (ASIAEX) East China Sea (ECS) Experiment. A multifrequency incoherent matched-field inversion processor and a genetic algorithm (GA) are used for the inversion. A multistep matched field inversion approach is presented, which makes use of the varying sensitivities of wave fields at various frequencies to reduce the inversion problem into a sequence of smaller inversions with fewer unknowns to estimate at each stage. Different parameters are estimated using data at different frequencies according to their sensitivities. Inversion results for different areas in the ECS region are summarized and compared with core data.     

地球化学景观吸引子的发现及其意义

勘查地球化学对异常评价的最大不确定性源于对地球化学景观特性的认识不够。我们应用构造相空间的方法分析了浙江儒岙幅（1:5万）水系沉积物测量的Ag含量数据，揭示了地球化学景观是具有低维吸引子（DZ≈2．9）的混饨系统。这一发现将对勘查地球化学中采样密度的选择、地球化学场模拟、异常评价等根本性问题产生重大影响。     

Impact evaluation on groundwater of the infiltration of an urban wastewater geopurification system placed over a detrital aquifer in a semiarid region (Spain)

Over a period of 4 years and 4 months, the geopurification installations at Dehesas de Guadix (Granada, Spain) were monitored to determine the impact on soil and groundwater of the controlled discharge of urban wastewater, and also to identify the best indicators of the entry of the recharged water into the aquifer. The installations are located in an area where the climate is Mediterranean sub-arid, with an average precipitation of less than 287 mm/year, and a rate of evapotranspiration that is almost three times greater. The system was controlled by determining the balance of majority nutrients and boron in the soil and in the groundwater, both at the points affected directly by the wastewater discharge and at others. The quantity of mass discharged was relatively large (COD 14,656 g/m², NO₃ 85 g/m², NO₂ 4 g/m², NH₄ 2,425 g/m², PO₄ 1,143 g/m², K 1,531 g/m², B 63 g/m²). It was observed that the elimination of nutrients within the soil (COD 97.5%, PO₄ 94.4%, K 59.17%, N _total 18.8%, B 12.69%) was very efficient except for the nitrogen, which nevertheless did not reach the groundwater, as it was eliminated at deep levels of the unsaturated zone. Only 12.69% of the boron was removed, and appreciable, increasing amounts of this element did reach the groundwater. Unexpectedly, none of the majority nutrients behaved as a reliable indicator of the impact on groundwater; despite this, the boron and the bicarbonate did clearly reflect the arrival of the recharged water, and are proposed as the best indicators.     

固定式海洋平台利用TLD的减震研究

本文研究固定式海洋平台利用调谐液体阻尼器（ＴｕｎｅｄＬｉｑｕｉｄＤａｍｐｅｒ，简称ＴＬＤ）减小地震反应的方法。首先探讨了调谐频率比、激磁频率比对减震效果的影响，在此基础上建立了ＴＬＤ——平台系统的力学模型和运动方程，通过数值计算验证了该方法的有效性     

好望角附近海域春季大风的几种主要形势分析

通过普查和分析，概括出了春季好望角附近海域三种主要大风出现时的模型图，并以一个月中逐日4次船舶测风报告为例，分析了好望角大风的某些主要特征。     

台湾海峡西岸第四纪沉积层中的老红砂

本文对采自福建沿海的老红砂作了粒度分析、矿物鉴定和石英电镜扫描。结果表明,组成老红砂的成分主要为中细砂,砂含量大于70%,粘土和粉砂含量较少。概率累积曲线多为跳跃、悬浮两段式,其次为滚动、跳跃、悬浮三段式。轻矿物以石英为主,长石含量居次。含量较高的重矿物有磁铁矿、钛铁矿、白钛石,其次有锆石、赤铁矿、褐铁矿、电气石、绿帘石等。文章对老红砂的成因提出一些粗浅的看法。     

一种提高粘土矿物去除赤潮生物能力的新方法

在研究粘土颗粒与赤潮生物絮凝作用的基础上，建立了粘土表面改性对其絮凝作用影响的理论模型，认为改变粘土颗粒的表面性质提高其去除赤潮生物能力的主要途径，提出在粘土中引入ＰＡＣＳ（聚羟基氯化铝）的改性方法。结果表明，对于微型原甲藻（Ｐｒｏｒｏ－ｃｅｎｔｒｕｍ ｍｉｎｉｍｕｎ）体系，粘土中引入微量ＰＡＣＳ后，其去除率达９０％以上的高岭土用量由原来的２ｇ／Ｌ降至０．１ｇ／Ｌ，去除效率提高近２０倍。考察了ＰＡ     

Climate changing characteristics of Zhangye City in Heihe River basin during 1968–2005

At present, researches on climate change of the Heihe River basin mainly focus on the relationship between basin climate change and regional water resources, regional desertification and dynamic climatic seasons of sandstorm, but less on climate change of oasis region, where there are more intense and frequent human activities. Based on data of precipitation, temperature, strong wind and dust events frequencies obtained from the six meteorological stations of Zhangye region in Heihe River basin, the features of climate change during 1968–2005 were carefully studied. Results show that the regional temperature rise rate exceeded the average level of China. The annual precipitation changed a little, but the precipitation had a slowly increasing trend in spring and winter. Frequencies of strong wind and sandstorm days show obviously descending trends, which had a close correlation with the regional temperature rise and the precipitation increase in spring and winter. Meanwhile, further human economic activities and exploitations to the oasis in the inland valley of arid regions also affected the climate change of this region, which has a sensitive and fragile eco-environment. __________ Translated from Journal of Desert Research, 2007, 27(6): 1048–1054 [译自: 中国沙漠]     

电容测试法判断测井电缆系统故障

测井电缆因长途颠簸、拉伸及绞车缠绕挤压,电缆连接器、电缆、绞车滑环、滑环连线等部位极易出现故障。电容测试法是一种简易、快速的检测方法,该法可在现场准确诊断出故障电缆的位置。以四芯铠装电缆为例,每根缆芯的正常阻值约为80Ω/1 000m,两缆芯间的分布电容约为170PPF/1 000m。在实际检测中,根据电容较小时测点的位置,可以有效判断故障部位;而电缆故障位置则可利用电阻及电容的线性关系进行计算予以确定。     

淄博市洪山、寨里煤矿地下水串层污染形成原因及防治

淄博市洪山、寨里煤矿区隐伏的奥陶系灰岩裂隙岩溶水污染严重。水质污染突发于矿坑全面闭坑以后，污染范围与矿坑水区一致，地下水污染组份与矿坑水的高含量组份相同。水质恶化主要由矿坑水串层污染所致。在此针对串层污染形成原因及影响因素，提出了防治对策。