关于大地电磁的静校正问题

本文从理论上严格地论述了大地电磁测深曲线静态位移的原理,简单介绍了目前国内外所采用的静校正方法,并着重分析了我们所用的压制表层电性不均匀干扰的办法及其效果。     

A dynamic network model for two‐phase immiscible flow

A dynamic pore‐scale network model is formulated for two‐phase immiscible flow. Interfaces are tracked through the pore throats using a modified Poiseuille equation, whereas special displacement rules are used at the pore bodies. The model allows interfaces to move over several pore‐lengths within a time step. Initial computational results are presented for a drainage experiment to demonstrate some of the features of the model. This revised version was published online in July 2006 with corrections to the Cover Date.     

GIS中曲线误差的模型与试验研究

提出了描述曲线整体误差的随机过程模型．用过程的数字特征函数定义了曲线的局部误差指标．用过程的积分定义了曲线的局部和整体误差指标．阐述了各指标的概率意义与几何意义．设计了过程模型的数字化试验，并提取了过程的样本曲线。通过对样本曲线的统计分析．得到了各误差指标的估计值。     

油浸式高压变压器地震易损性分析

油浸式变压器是由多种材料组成的复杂结构。本文对油浸式高压变压器建立了较为精确的有限元模型，考虑了各组件之间相互作用的影响。对该设备进行了动力性能和地震响应分析以及易损性分析。分析结果表明，大型高压变压器在地震中的首要破坏模式为瓷套破坏，其地震响应的离散度较高。易损性分析得到设备的地震易损性曲线，可直接应用于电力系统的抗震分析。     

Analysis of the impact of conservation measures on stream flow regime in catchments of the Loess Plateau,China

Catchments in the Loess Plateau have been under the influence of human activities for centuries. In the last four decades, soil conservation measures have accelerated and intensified. These measures were designed to reduce soil erosion, improve agricultural productivity, and enhance environmental quality. It is important to evaluate the effects of these measures on hydrology in order to develop sustainable catchment management plans in the region. This study evaluated changes in stream flow data for four selected catchments in the Loess Plateau following large‐scale soil conservation measures. The non‐parametric Mann–Kendall test was used to identify trends in annual stream flow and the results showed significant downward trends in three of the four catchments. The Pettitt test indicated that a change point occurred in 1978 in these three catchments. Annual precipitation in all the catchments showed no significant trend during the period of record. Comparison of daily flow duration curves for two 20‐year periods (1957–1978) and (1979–2003) showed significant changes in stream flow regime. Reduction in most percentile flows varied between 20 and 45%, and the reduction in low flows was greatest. Overall, the reductions in daily flow were increasing with time, with significant changes occurring in the 1990s. However, it is not clear whether these catchments have seen the full effects of the soil conservation measures, so the results of this study might underestimate the final impact of soil conservation on stream flow regime. Copyright © 2007 John Wiley & Sons, Ltd.     

Testing the nonsysmmetric gravitational theory with rotation curves of galaxies

We use the rotation curves of 13 galaxies to test the nonsymmetric gravitaional theory (NGT). If we follow Moffat's assumption of a constant mass-to-light for all galaxies then we shall find that the two supposedly universal constants r₀, L₀ to show a large scatter. By regarding the mass-to-light ratio as a free parameter for each galaxy, and adjusting the values of r₀, L₀, we find that NGT can well account for the observed rotation curves. Further, the mass-to-light ratios so found show the well-known trend along the Hubble morphological sequence.     

P–Y Curves for Piles Under Seismic Lateral Loads

This paper describes an experimentally based procedure for building dynamic P–Y curves for clays from the Campeche sound in the Gulf of Mexico and for Mexico City clays. Cyclic triaxial and resonant column tests were used to derive hyperbolic stiffness–strain and damping–strain functions that depend on soil plasticity and on relative consistency. The dynamic P–Y curves incorporate these functions and also include hysteretical and geometrical damping characteristics of the pile–soil system; they can be used directly in dynamic interaction analyses of structure–pile–soil systems in the time or the frequency domains. Usual practice relies on pseudo static formulations and a simplified alternative to include P–Y curves in this kind of analysis is also proposed, which is essentially the same as the dynamic ones but does not include radiation or hysteretical damping.     

利用自记水位仪记录的连续曲线求水文地质参数

水文地质参数是进行地下水资源评价和开发利用的科学依据。给水度（μ）和降水入渗补给系数（α）是重要的水文地质参数。自记水位仪记录的是地下水位的连续变化,它在时空获得的信息量远超过目前测水钟的观测方法。本文利用自记水位仪记录的连续曲线,求得给水度（μ）和降水入渗补给系数（α）。     

Design hydrograph estimation in small and ungauged watersheds: continuous simulation method versus event‐based approach

The proper assessment of design hydrographs and their main properties (peak, volume and duration) in small and ungauged basins is a key point of many hydrological applications. In general, two types of methods can be used to evaluate the design hydrograph: one approach is based on the statistics of storm events, while the other relies on continuously simulating rainfall‐runoff time series. In the first class of methods, the design hydrograph is obtained by applying a rainfall‐runoff model to a design hyetograph that synthesises the storm event. In the second approach, the design hydrograph is quantified by analysing long synthetic runoff time series that are obtained by transforming synthetic rainfall sequences through a rainfall‐runoff model. These simulation‐based procedures overcome some of the unrealistic hypotheses which characterize the event‐based approaches. In this paper, a simulation experiment is carried out to examine the differences between the two types of methods in terms of the design hydrograph's peak, volume and duration. The results conclude that the continuous simulation methods are preferable because the event‐based approaches tend to underestimate the hydrograph's volume and duration. Copyright © 2011 John Wiley & Sons, Ltd.     

惠民凹陷唐庄地区沙河街组层序地层和沉积相

针对研究区的区域地质概况,并借鉴了前人的研究成果,利用地震和测井资料识别出了三级层序边界,并对各层序进行了体系域划分,建立了研究区的等时地层格架。在此基础上,通过对岩芯和测井相的综合分析,以体系域为单位进行了沉积相的划分,建立了研究区的精细沉积相模型,并对沉积相的展布特征进行了分析。