At‐a‐station hydraulic geometry relations, 1: theoretical development

This paper, the first of two, hypothesizes that: (1) the temporal variation of stream power of a river channel at a given station with varying discharge is accomplished by the temporal variation in channel form (flow depth and channel width) and hydraulic variables, including energy slope, flow velocity and friction; (2) the change in stream power is distributed among the changes in flow depth, channel width, flow velocity, slope, and friction, depending on the boundary conditions that the channels has to satisfy. The second hypothesis is a result of the principle of maximum entropy and the theory of minimum energy dissipation or its simplified minimum stream power. These two hypotheses lead to families of at‐a‐station hydraulic geometry relations. The conditions under which these families of relations can occur in the field are discussed. Copyright © 2007 John Wiley & Sons, Ltd.     

Non-Darcian groundwater flow in leaky aquifers

Abstract

A simplified method has been developed for solving leaky aquifer non-Darcian flow hydraulics. The principle of volumetric approach is combined with the confined-aquifer, time-dependent drawdown equation in an observation well. The groundwater flow in the leaky aquifer is assumed to obey a non-Darcian flow law of exponential type. The results are obtained in the form of type-curve expressions from which the necessary bundles of curves are drawn for a set of selective non-Darcian flow aquifer parameters. Although application of the methodology appears as rather limited but it provides a scientific contribution and extension of leaky aquifer theory towards nonlinear flow conditions. The methodology developed herein is applied to some actual field data from the eastern sedimentary basin in the Kingdom of Saudi Arabia.     

Water source characterization through spatiotemporal patterns of major,minor and trace element stream concentrations in a complex,mesoscale German catchment

The link between spatiotemporal patterns of stream water chemistry and catchment characteristics for the mesoscale Dill catchment (692 km²) in Germany is explored to assess the catchment scale controls on water quality and to characterize water sources. In order to record the spatiotemporal pattern, ‘snapshot sampling’ was applied during low, mean and high flow, including 73 nested sites throughout the catchment. Water samples were analysed for the elements Li, B, Na, Mg, Al, K, Ca, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Rb, Sr, Mo, Ba, Pb and U using inductively‐coupled‐plasma mass spectrometry, and for electric conductivity and pH. Principle component analysis and hierarchical cluster analysis were used to find typical element associations and to group water samples according to their hydrochemical fingerprints. This revealed regional hydrochemical patterns of water quality which were subsequently related to catchment attributes to draw conclusions about the controls on stream chemistry. It was found that various lithologic signals and anthropogenic point source inputs controlled the base flow hydrochemistry. During increased flows, stream waters were diluted causing additional hydrochemical variability in response to heterogeneous precipitation inputs and differences in aquifer storage capacities. The hydrochemical patterns further displayed in‐stream mixing of waters. This implied, that stream waters could be apportioned to the identified water sources throughout the catchment. The basin‐wide hydrochemical variability has the potential to outrange the tracer signatures typically inferred in studies at the hillslope scale and is able to strongly influence the complexity of the catchment output. Both have to be considered for further catchment scale tracer and modelling work. Despite the likelihood of non‐conservative behaviour, the minor and trace elements enhanced the rather qualitative discrimination of the various groundwater types, as the major cations were strongly masked by point source inputs. Copyright © 2007 John Wiley & Sons, Ltd.     

方程误差系统的多新息辨识方法

多新息方法可以用于线性系统和非线性系统的自适应滤波、参数估计、自校正控制、自适应故障检测与诊断等.线性系统包括两种基本类型:方程误差类系统和输出误差类系统.本文将多新息辨识应用到方程误差滑动平均(EEMA)系统(即CARMA系统),研究多新息增广随机梯度算法和多新息增广最小二乘算法,应用到方程误差自回归滑动平均(EEARMA)系统(即CARARMA系统),提出基于分解的多新息广义增广随机梯度算法和基于分解的多新息广义增广最小二乘算法,以及基于滤波的多新息广义增广随机梯度算法和基于滤波的多新息广义增广最小二乘算法.     

船舶自动气象站分类标准及仪器布设原则

本文在研究分析各类船舶的基础上,对船舶自动气象站(船舶站)的基本构成和采集要素进行了分类,提出了船舶站构成的分类标准,解决了不同船舶选取安装不同要素自动站选择依据不足的问题,详述了船舶站的构成。以典型船舶站为例,详述了温、压、湿、风、降水、能见度、辐射等观测要素的安装位置选择,为船舶站的设计和安装提供参考依据。     

全景深度图像精度分析及优化方法研究

针对三维激光点云数据生成360°全景深度图像存在像素分辨率不均匀的问题,提出一种顾及目标量测精度及可见度的全景深度图像生成方法,在保证全景影像表达地物的完整性的前提下提高其数据的存取精度。通过坐标转换和投影变换生成与全景影像匹配的全景深度图像;基于摄影成像原理分析摄影中心高度、深度值和像素分辨率之间的关系,得到不同深度处目标分辨率随摄影中心升高趋于一致的结论;综合分析地面目标分辨率和杆状目标尤其是树冠对树干的遮挡问题,确定特定场景下生成全景深度图像的最佳摄影中心位置并重新生成深度图像。实验分析表明,该方法能够在保证杆目标可见度的前提下提高地面目标量测精度。     

新型电磁式孔底冲击器工作机理研究

冲击回转钻进是一种提高硬岩钻探效率的有效方法,实现冲击回转钻进的关键设备是冲击器。针对现有液动、风动冲击器在应用中存在的不足,提出了利用可充电电池组为动力的新型电磁式孔底冲击器的设计思路。详细介绍了新型电磁式孔底冲击器的结构和工作原理,对冲击器的控制系统、电磁驱动部分及电池组供电方案等关键设计技术进行了阐述。研究表明,新型电磁式孔底冲击器能够克服液动、风动冲击器的众多不足、优点显著,具有广泛的推广应用前景。     

埕岛油田水淹层测井响应原理及识别

本文依据油层导电原理和阿尔奇公式建立了埕岛油田水淹层解释的理论基础。在对埕岛油田注入水水性分析后,确定了水淹层的电性变化特征;进行水淹层解释的过程中,根据不同的测井曲线特征分别建立了自然电位基线偏移法、自然电位与电阻率对应分析法、交汇图版法和综合分析法等水淹层解释方法,并在埕岛油田水淹层解释中得到了成功应用,为埕岛油田剩余油饱和度解释奠定了基础。     

带Sobolev临界指数的非齐次拟线性椭圆型方程正解的存在性

在RN上讨论带临界项的拟线性椭圆型方程正解的存在性问题。在一个正锥上应用Ekeland变分原理构造一个比P.S(.)c序列要弱的序列,通过证明该序列具有相对紧性,得到一个弱正上解,进而利用上下解方法得出所研究的问题至少存在一个弱正解。     

琼东南盆地深水区断层垂向输导及成藏模式

In the Qiongdongnan Basin, faults are well developed.Based on the drilling results, the traps controlled two or more faults are oil-rich. However, when only one fault cut through the sand body, there is no sign for hy-drocarbon accumulation in the sandstone. In terms of this phenomenon, the principle of reservoir-forming controlled by fault terrace is proposed, i.e., when the single fault activates, because of the incompressibility of pore water, the resistance of pore and the direction of buoyancy, it is impossible for hydrocarbon to ac-cumulate in sandstone. But when there are two or more faults, one of the faults acts as the spillway so the hydrocarbon could fill in the pore of sandstone through other faults. In total five gas bearing structures and four failure traps are considered, as examples to demonstrate our findings. According to this theory, it is well-advised that south steep slope zone of Baodao-Changchang Depression, south gentle slope zone of Lingshui Depression, north steep slope zone of Lingshui Depression, and north steep slope zone of Baodao Depression are the most favorable step-fault zones, which are the main exploration direction in next stage.