过套管电阻率测井仪器的径向探测特性

为研究过套管电阻率测井仪器的径向探测特性,本文给出了反映地层径向介质变化的几何因子.利用过套管电阻率测井的传输线方程实现了电阻率测井几何因子的数值计算,针对Schlumberger公司的CHFR测井仪和俄罗斯的ЭКОС-31-7测井仪分别计算了几何因子响应曲线,通过曲线分析发现：两种测井仪对低侵剖面（有低阻流体侵入）均有较大的探测半径,但随侵入流体电阻的增大（高侵剖面）仪器的径向探测半径在减小,本文的研究为地层电阻率测井解释和仪器径向探测特性分析提供了理论依据.     

Effect of mineral reactions on the hydraulic properties of unsaturated soils: Model development and application

The selective radius shift model was used to relate changes in mineral volume due to precipitation/dissolution reactions to changes in hydraulic properties affecting flow in porous media. The model accounts for (i) precipitation/dissolution taking place only in the water-filled part of the pore space and further that (ii) the amount of mineral precipitation/dissolution within a pore depends on the local pore volume. The pore bundle concept was used to connect pore-scale changes to macroscopic soil hydraulic properties. Precipitation/dissolution induces changes in the pore radii of water-filled pores and, consequently, in the effective porosity. In a time step of the numerical model, mineral reactions lead to a discontinuous pore-size distribution because only the water-filled pores are affected. The pore-size distribution is converted back to a soil moisture characteristic function to which a new water retention curve is fitted under physically plausible constraints. The model equations were derived for the commonly used van Genuchten/Mualem hydraulic properties. Together with a mixed-form solution of Richards’ equation for aqueous phase flow, the model was implemented into the geochemical modelling framework PHREEQC, thereby making available PHREEQC’s comprehensive geochemical reactions. Example applications include kinetic halite dissolution and calcite precipitation as a consequence of cation exchange. These applications showed marked changes in the soil’s hydraulic properties due to mineral precipitation/dissolution and the dependency of these changes on water contents. The simulations also revealed the strong influence of the degree of saturation on the development of the saturated hydraulic conductivity through its quadratic dependency on the van Genuchten parameter α. Furthermore, it was shown that the unsaturated hydraulic conductivity at fixed reduced water content can even increase during precipitation due to changes in the pore-size distribution.     

2003年新疆巴楚-伽师地震序列的双差法重新定位研究

将近台记录和区域台网数据联合用于双差地震定位算法,对2003年新疆巴楚-伽师MS68强震后404个ML≥35余震序列进行双差法重新精确定位,并对其进行了理论上的可行性分析. 精定位后定位结果与传统定位方法的原始定位结果进行比较发现：（1）精定位后震中分布图像更加集中,与当地的烈度考察和震源机制解结果更加协调;（2）震源深度优势分布集中在15～25km以内,与当地存在深度为10km以上低速沉积层的地质构造情况相一致;（3）精定位后定位残差由原来的394s降为024s,水平向估算误差平均可控制在11km以内,垂直向估算误差平均可控制在24km.     

非平稳时间序列的动态水位神经网络预报模型

水文预报系统是一个复杂的非线性动力学过程,站点水位受各种因素的影响不仅呈现出非平稳动态随机变化特性,而且各因素间的关系也很难确定。淮河流域五河站水位由于受到洪泽湖回水影响及季节性的影响,也呈现出这一动力学的非平稳特性,因此本文在考虑了相关站点和回水影响的基础上,建立了一种多站变量时间序列的神经网络预报模型,预报结果表明该方法预测效果较好,运行简单。     

Holocene development of the River Lippe valley,Germany: a case study of anthropogenic influence

The characteristics of the Holocene valley floor of the River Lippe, Germany, are atypical for a river in central Europe. The valley floor consists of three terrace levels, which are not always clearly separated from each other. Analysis of the sediments making up the terraces indicates that they accumulated during the course of the entire Holocene, although there is insufficient information available to allow detailed determination of phases of fluvial change and stability responsible for terrace formation. Two of the terraces exist only in the lower reaches of the valley, where they converge and diverge with the third. The lowest terrace consists only of a narrow strip, running parallel to the river channel. The configuration of the valley floor may be explained by a series of anthropogenic influences. The earliest human impact probably occurred about 2000 years ago when, during their campaign against German tribes, the Romans built a towpath and may have changed the channel planform from its natural, anabranching pattern to a meandering form by building small dams on local distributary forks. Implementation of artificial meander cut‐offs to improve navigation on the river began in medieval times. The morphological response to these human interventions was primarily degradational. In the 19th century, artificial lateral fill was used to narrow the channel and the towpath was renewed several times. The trace of the most recent towpath is still discernible as a narrow strip parallel to the river channel, and it constitutes the lowest terrace level. Comparison between the bankfull discharge of a 4000‐year‐old abandoned channel and the formative flow for the modern channel supports the premise that, prior to anthropomorphic influence, the natural planform was anabranched. Copyright © 2000 John Wiley & Sons, Ltd.     

非汛期影响海南热带气旋的活动变化特征

根据1949～2002年共54年的台风资料对非汛期(10月～次年4月)西北太平洋台风活动的气候特点进行了统计分析,指出:非汛期内影响、严重影响海南的热带气旋频次均无明显的减少趋势,其频次存在准10年、15～20年的主周期,其年代际变化表现为1950年代中期～1960年代后期偏少,1970年代前期偏多,1970年代后期偏少,1980年代偏多,1990年代偏少;非汛期内严重影响海南的较强的热带气旋主要出现在拉妮娜年且其年代际变化也存在15～20年的主周期,1950年代后期到1960年代前期活动的热带气旋偏弱,1960年代后期～1970年代前期偏强,1970年代后期偏弱,1980年代偏强,1990年代又偏弱;较强的热带气旋(中心极值940hPa以下)均生成于135°E以东的洋面,而其源地越西,其强度越小;非汛期登陆海南的热带气旋的登陆点均处于海南岛的东侧海岸线上,1970年代中期以后,登陆点有南移趋势,且均以台风形式登陆。     

考虑中主应力时土体劈裂灌浆力学机制的大变形分析

在塑性力学和大变形理论的基础上分析土体在劈裂灌浆初始阶段的力学机制,将劈裂灌浆的初始阶段视为无限土体中的圆孔扩张问题,并将圆孔周围土体中的应力分布分为两个区域。在弹性区中土体服从小变形假设,在塑性区中服从大变形假设。假设初始劈裂灌浆压力是圆孔扩张到极限时极限扩孔压力;当土体在灌浆压力作用下,大小主应力正好换位时,则出现劈裂时的灌浆压力就为二次劈裂灌浆压力值,推导出塑性区半径、劈裂灌浆的竖向劈裂灌浆和水平向劈裂灌浆压力的理论解答,同时也获得了弹塑性区中的应力场分布规律。该理论的计算结果与工程实测结果比较接近,初步证实了该理论的可靠性。     

NCC/IAP T63海气耦合模式对云滴有效半径的敏感性分析

利用NCC/IAP T63海气耦合模式研究了模拟对云滴有效半径的敏感性。结果表明,可变水云粒子有效半径的引入（REL和REL_CAM3方案）导致对流层中下部云消光光学厚度的明显变化,但REL和REL_CAM3之间的变化位置不同、符号相反;而引入可变的冰云粒子有效半径后（REI方案）,对流层中上部的云消光光学厚度明显减小。云辐射强迫的变化主要受REI方案的影响,长波和短波云辐射强迫均以减小为主;从全球平均来看,大气顶云辐射强迫的变化对冰云有效半径的变化更加敏感,尽管量级还有明显差距,各种方案均正确模拟出了大气顶净云辐射强迫的符号。大气顶净辐射的变化与净云辐射强迫的变化基本一致,总体以减少为主。对于地表气温的变化,REL和REI方案总体上有着较为一致的分布,夏季以降温为主,冬季的欧亚大陆中部和北美北部增温明显。此外,大陆地表气温的变化主要受地表热量输送的影响,而热带海洋上空却表现出明显的不一致性。同时引入可变的水云和冰云粒子（RIW和RIW_CAM3方案）,云的消光光学厚度和辐射强迫相对单独引入主要呈线性响应,但地表气温表现出明显的非线性特征,非线性最明显的地区主要位于大陆地区。       

邯郸地区一次登陆台风大暴雨过程观测分析

受登陆台风"海棠"减弱后低压与东移锋面云系的共同影响,2005年7月21日夜间到23日早晨邯郸地区出现了大范围的暴雨天气。本文从天气形势、水汽输送特征、云系演变特征和大气不稳定条件等方面进行分析,探讨了这次登陆台风暴雨天气的成因。结果表明,台风低压、稳定少变的副热带高压以及500 hPa低槽相互作用,共同造成了这次暴雨天气过程,高纬弱冷空气南下,与台风携带的暖湿空气相遇,加之太行山地形的影响,造成暖湿空气抬升,使得冀南地区产生中尺度对流云团,进而发生强降水。地面自动站以及加密站风场资料分析指出,低空偏北风与偏东风之间的中尺度辐合线对暴雨发生有重要作用,其出现的时间和位置决定了中尺度暴雨天气的发生时间和位置。在水汽输送方面,西部山区的暴雨区水汽主要来源于南海和东海,而东部平原地区的大暴雨,其水汽主要来源于南海。简单的层结分析表明,暴雨区上空存在对流不稳定和对称不稳定共存的现象,两者共同为系统发展和暴雨发生提供了不稳定条件。     

马16井开采对马17井水动态观测的影响

为了验证平原地区深井水动态观测受环境条件影响的情况,我们选择了河北省河间地区马17地震观测井和马16地热开发井进行对比观测,试图探讨马16井开采对马17井水动态观测的影响。结果表明马17井的动水位年变化是气压干扰所致,与马16井采水无明显关系。马16井冬季开采热水对马17井动水位观测无明显影响。