“面型”岩石地球化学测量方法与应用实例

“面型”岩石测量方法可成倍地减少样品采集量和分析工作量,大幅度降低了工作成本。增强了样品的代表性,并且能够消除“测网效应”,快速有效地查明区域或矿区地球化学特征以及矿化富集部位。     

Coarse bed load transport in an alluvial gravel bed stream,Dupuyer Creek,Montana

Coarse bed load was sampled in a gravel/cobble bed stream during two major floods in the snowmelt runoff season. The channel is characterized by high rates of bank erosion and, therefore, high rates of sediment supply and bed load flux. Peak discharge reached four times bank‐full, and bed load was sampled at flows 0·7–1·7 times bank‐full. A large aperture bed load sampler (1 m by 0·45 m) captured the largest particles in motion, and specifically targeted the coarse bed load size distribution by using a relatively large mesh (32 mm or D₂₅ of streambed surface size distribution). Bed load flux was highly variable, with a peak value of 0·85 kg/s/m for the coarse fraction above 38 mm. Bed load size distribution and maximum particle size was related to flow strength. Entrainment was size selective for particles D₇₀ and larger (88–155 mm), while particles in the range D₃₀–D₇₀ (35–88 mm) ceased to move at essentially the same flow. Bed load flux was size selective in that coarse fractions of the streambed surface were under‐represented in or absent from the bed load. Painted tracer particles revealed that the streambed surface in the riffles could remain stable even during high rates of bed load transport. These observations suggest that a large proportion of bed load sediments was sourced from outside the riffles. Repeat surveys confirmed major scour and fill in pools (up to 0·75 m), and bank erosion (>2 m), which together contributed large volumes of sediment to the bed load. Copyright © 2007 John Wiley & Sons, Ltd.     

北京平原地下水水位监测网优化

文章在北京市地下水水位监测现状基础上,分潜水和承压水对北京平原地下水监测网的监测密度和监测频率进行了优化设计。主要采用编制地下水动态类型图的方法进行了地下水水位监测网的优化,克里金插值法能定量评价依据监测网观测值绘制的地下水水位等高线的精度,因而可以用来评价监测优化结果。并根据时间序列分析和统计检验提供的定量标准优化了地下水水位监测频率。优化后,北京平原共有监测孔400眼,其中利用原有监测孔300眼,新设计监测孔100眼,手工监测频率由原来的每月6次优化为每月1次,专项高频率监测可以由地下水自动监测仪实现。文中还对地下水自动监测仪(DIVER)的监测结果和手工监测结果进行了对比评价,提出了地下水水位监测网的维护、管理措施和信息发布方式。     

试论地质资料档案的保密与开发利用

地质资料作为一种特殊商品,具有公益性和商业性两重属性。地质资料具有其商品属性,在市场经济条件下,价值意义重大。在分析了几种主要的泄密形式后,提出了地质资料档案的保密原则及措施。但是地质档案资料的价值在于开发利用,新形势下进一步加强地质档案资料的科学管理,维护档案资料所有者的合法权益,有效开发利用馆藏地质资料,实现其应有的价值,为国民经济发展服务,是地质资料档案管理工作者的光荣和艰巨的使命。     

高压喷射灌浆防渗技术在水库大坝基础处理中的应用

高压喷射灌浆防渗技术是国内正在推广的一种新型防渗技术,适用范围较广。阜康市红山水库始建于70年代,当时未对坝基11.5~4.2m厚漂卵砾石层进行防渗处理。本次除险加固对坝基采用了高压喷射灌浆防渗处理,经检测防渗质量满足相关规范要求。高压喷射灌浆技术在漂卵砾石层中的成功应用,对该项技术的推广具有参考价值。     

黄河流域两类取样环境的树木年轮生长量订正分析*

黄河流域存在着两类不同的树木年轮取样环境。在典型的取样环境中,树木生长多遵循缓慢递减的规律,作生长量订正时,可采用传统的树木年轮学订正方法。在非典型的取样环境中,树木生长形式较为复杂,可引进新的分析途径,包括多项式函数和样条函数的应用。随样本环境的不同,各类订正分析的可适用性亦有差异。     

The combination of sampling and kriging in the regional estimation of coal resources

Two-dimensional systematic sampling of small plots followed by the kriging of those plots may be employed to obtain regional estimates of coal resources and measures of the accuracy of the estimates. The use of sampling makes large savings in computation possible. Two case studies involving the estimation of coal tonnage are discussed.     

Some exact sampling distributions for variogram estimators

For equally spaced observations from a one-dimensional, stationary, Gaussian random function, the characteristic function of the usual variogram estimator for a fixed lag k is derived. Because the characteristic function and the probability density function form a Fourier integral pair, it is possible to tabulate the sampling distribution of a function of a using either analytic or numerical methods. An example of one such tabulation is given for an underlying model that is simple transitive.     

Analytical studies on some statistical properties of mean values and their applications to sampling in one dimension

This paper documents the results of investigations on the variance and covariance properties of mean values within the theory of stationary random functions under a variety of conditions. Analytical expressions have been developed in each case, to facilitate direct and ready applications of the results, using the exponential function as a working model for the covariance function. These properties, in turn, have been utilized in developing mathematical expressions for estimation accuracy (error variance) of the mean estimates for one-dimensional sampling plans. Two distinctly different sampling plans have been discussed: punctual sampling with no significant linear extensions of the samples and linear sampling with significant linear extensions of samples in the direction of the section being sampled.