第二次土地调查数据库成果在土地勘测定界中的应用

介绍了第二次土地调查数据库成果在勘测定界中的应用,进一步规范了土地勘测定界成果资料,确保了成果质量,真正做到了图、数与实地一致,并通过生产实际探讨了县级土地勘测定界内外业工作方法。     

区域似大地水准面精化算法及成果三维仿真研究

利用GPS水准代替繁重的几何水准测量工作,必须确定高精度、高分辨率的似大地水准面。本文分别介绍了函数模型算法、随机模型算法和综合模型算法,并基于试验区域的GPS水准数据,通过各种算法的分类计算比较,验证了这几种模型算法的有效性和可靠性,结果证明最小二乘配置算法精度较高,并对实验结果进行三维仿真,可视化的分析似大地水准面的变化。     

油企业抗震防灾规划信息管理系统的设计

基于石油企业抗震防灾工作对网络与数据库的信息管理系统的需求，对数据库产品进行了简要分析，并根据石油企业抗震防灾规划的需求和信息管理的一般模式，提出了石油企业抗震防灾规划信息计算机管理系统的设想。认为，以 Ｍｉｃｒｏｓｏｆｔ Ａｃｃｅｓｓ 数据库软件为基础，利用 Ｖ Ｂ或 Ｖ Ｃ等可视化前端应用开发工具，是目前比较好的方案，它将使石油企业抗震防灾规划工作在办公自动化方面迈向新的台阶     

也论二十世纪中国文学发展中的民间文化思潮——兼与高有鹏先生商榷

文学思潮与民间文化都是具有特定内涵的严格概念，与其他思潮既有联系又有区别，民间文化因为自己特殊的存在状态和创造主体而形不成思潮，二十世纪中国文学发展中的五大运动都与民间文化有关，但是不能以民间文化思潮的面目出现。高有鹏先生的《论二十世纪中国文学发展中的民间文化思潮》命题不准确，文中尚有许多可以商榷之处。     

The onset of chaotic motion in the restricted problem of three bodies

A full characterization of a nonintegrable dynamical system requires an investigation into the chaotic properties of that system. One such system, the restricted problem of three bodies, has been studied for over two centuries, yet few studies have examined the chaotic nature of some ot its trajectories. This paper examines and classifies the onset of chaotic motion in the restricted three-body problem through the use of Poincaré surfaces of section, Liapunov characteristic numbers, power spectral density analysis and a newly developed technique called numerical irreversibility. The chaotic motion is found to be intermittent and becomes first evident when the Jacobian constant is slightly higher thanC ₂.     

Three‐dimensional finite element analysis of the interaction between tunneling and pile foundations

This paper concerns analysis of the impact of construction of urban tunnels on adjacent pile foundations. It is carried out using an elastoplastic three‐dimensional finite element modelling. Numerical simulations are performed in two stages, which concern, respectively, the application of the pile axial loading and the construction of the tunnel in presence of the pile foundations. Analysis is carried out for both single piles and groups of piles. Results of numerical simulations show that tunneling induces significant internal forces in adjacent piles. The distribution of internal forces depends mainly on the position of the pile tip regarding the tunnel horizontal axis and the distance of the pile axis from the centre of the tunnel. Analysis of the interaction between tunneling and a group of piles reveals a positive group effect with a high reduction of the internal forces in rear piles. Copyright © 2002 John Wiley & Sons, Ltd.     

The applicability of research on flood-drought tendency —an analysis on disastrous flood of Taihu Lake basin in June-July, 1991

In Taihu Lake basin during June–July in 1991, there happened a catastrophic flood, the precipitation reached that of 1954 and the water level was the highest in the history in Taihu Lake. This heavy flood, happening in the relatively humid period and being well accord with flood-drought change tendency, was early precautioned. The occurrence of the flood illustrated that using records of historical climate to predict flood-drough tendency is practically significant for hazard-reduction project.     

Virtual Field Geologic Trip System

Virtual Field Geologic Trip System (VFGTS) constructed by the technique of visualization can efficiently present geologic field information and widely used in the field of geologic education. This paper introduces the developing thinking of VFGTS and discusses the main implement processes. Building VFGTS mainly includes systemically gathering of field geological data, the building of virtual geological world, and displaying of virtual geologic world and human-computer interaction.     

A bimodal four‐parameter lognormal linear model of soil water repellency persistence

Soil water repellency may be characterized in terms of the delayed infiltration time of a water droplet resting on the soil surface, which is, water drop penetration time (WDPT), or repellency persistence. Such repellency persistence varies nonlinearly with soil water content (θ_g), although no models have been proposed to reproduce the variation of WDPT with θ_g in soils. Dynamic factor analysis (DFA) is used to identify two common patterns of unexplained variability in a scattered dataset of WDPT versus θ_g measurements. A four‐parameter lognormal distribution was fitted to both common patterns obtained by DFA, and these were combined additively in a weighted multiple linear bimodal model. We show how such an empirical model is capable of reproducing a large variety of WDPT versus θ_g curve shapes (N = 80) both within a wide range of measured WDPTs (0–17 000 s) and for samples with organic matter content ranging from 21·7 to 80·6 g (100 g)^?1. Copyright © 2009 John Wiley & Sons, Ltd.     

含交叉断层的复杂地质体3维建模算法研究

在矿井生产中,出现交叉断层的区域往往是地质构造非常复杂的地方,也是危险高发的区域.对含交叉断层的3维地质建模的算法进行了研究.其主要思想是分别建立岩层和断层的TIN模型,以断层交线作为约束条件,进行带约束三角剖分,从而建立起交叉断层模型.这将有利于矿山的工程管理,减少危险的发生,作为后续采矿生产的依据.