基于MODIS的藏北高原植被分类研究

本文以那曲地区和拉萨市区(文中称藏北高原)作为研究对象,对该区域的植被进行分类。通过地面调查数据、遥感数据、中国植被图集扫描图中经几何校正的西藏藏北高原作为实际参考数据,利用R2V软件和Arc info软件的结合,得出西藏藏北高原植被的数字化图。同时通过中国植被图集中西藏藏北高原的数据和MOD IS卫星6、2、1通道合成数据的特点,利用最大似然估计监督类方法对2004年9月13和27日的EOS/MOD IS卫星遥感图像的西藏藏北高原部分植被进行分类。得出西藏藏北高原7个典型植被类型及其面积,可以反映出该区域植被的特征。这对可持续发展该区域的草地资源提供了决策依据。     

Use of Pistachio Shells as an Adsorbent for the Removal of Zinc(II) Ion

In this study, the removal of zinc(II) ion from an aqueous solution by pistachio shells (PS) is investigated. The dynamic behavior of the adsorption is examined on the effects of pH, adsorbent dosage, and contact time. The adsorption rates are determined quantitatively and simulated by the Lagergren first order, pseudo‐second order, Elovich, and intra‐particle diffusion kinetic models. The adsorption kinetic models are also tested for validity. The thermodynamic parameters, which are also deduced from adsorption experiments, are very useful in elucidating the nature of adsorption. The experimental results reveal that the optimum pH value and the contact time for the adsorption of Zn²⁺ onto PS are found as 6 and 10 min, respectively. According to these parameters, adsorption process follows the pseudo‐second order kinetic model with high correlation coefficients (R² = 0.999). The obtained results demonstrate that PS is a reasonably effective adsorbent for the removal of Zn²⁺ from aqueous leachate of hazardous waste.     

弹性层状半空间中无限长洞室对斜入射平面SH波的三维散射(Ⅱ)——数值结果与分析

以基岩上单-土层场地为例,计算分析了在斜入射平面SH波作用下弹性层状半空间中无限长洞室附近的地表位移.研究表明,层状半空间中地下洞室对波的散射与均匀半空间情况存在显著差别.层状场地由于考虑了场地自身的动力特性,使得洞室附近地表位移幅值的空间变化更为复杂,基岩与土层刚度比、土层厚度对散射效应均有着重要影响.随着基岩与土层刚度比的增大,地表位移幅值整体上逐渐增大;随着土层厚度的增大,土层对地表位移幅值的影响逐渐减小.在频域解答的基础上,给出了层状半空间中洞室对斜入射SH波散射的时域解答,并以Ricker波为例进行了数值计算.     

斜入射平面SH波在层状半空间中沉积谷地周围的三维散射

The indirect boundary element method （IBEM） is used to study three-dimensional scattering of obliquely incident plane SH waves by an alluvial valley embedded in a layered half-space. The free-field response of the layered half-space is calculated by the direct stiffness method, and dynamic Green＇s functions of moving distributed loads acting on inclined lines in a layered half-space are calculated to simulate the scattering wave field. The presented method yields very accurate results since the three-dimensional dynamic stiffness matrix is exact and the moving distributed loads can act directly on the valley boundary without singularity. Numerical results and analyses are performed for amplification of obliquely incident plane SH waves around an alluvial valley in a uniform half-space and in single layer over half-space. The results show that the three-dimensional responses are distinctly different from the two-dimensional responses, and the displacement amplitudes around alluvial valleys in a uniform haft-space are obviously different from those in a layered half-space.     

Investigation of the Possibility of Copper Removal from Industrial Leachate by Raw and Calcined Phosphogypsum: D‐Optimal and Taguchi Designs

In the present study, the removal of Cu(II) was evaluated by raw and calcined phosphogypsum (PG) as an industrial product. The role of experimental factors on the removal of Cu(II) was examined by using D‐optimal and Taguchi designs. The experimental factors and their related levels were selected as initial pH of 3–6–8, adsorbent content of 5, 10, and 25 g L^?1, contact time of 5, 10, and 20 min, and temperature of 20, 40, and 60°C. The results are evaluated by ANOVA test to extract important experimental factors and their levels. The performances of the suggested factorial designs were then compared and regression models that took into account the significant main and interaction effects were suggested. Taguchi design was found as a reliable solution with less number of experiments for adsorption studies with the optimized values. The resultant removal efficiency is calculated as 78.34%. The results revealed that calcined PG is an appropriate adsorbent for Cu(II) removal from leachate of industrial waste.     

基于等效介质理论分析川中低孔砂岩的骨架结构分析(英文)

川中广安地区的致密含气砂岩储层具有分布广,丰度低的特点。采自该地区的砂岩样本孔隙度普遍偏低,孔隙连通性差。本文采用Mori-Tanaka模型分析致密砂岩样本的波速观测数据,基于理论与实验分析,给出了该地区砂岩骨架的物理模型。通过经验关系获取基质模量,将实验数据与Mori-Tanaka模型在不同孔隙形态时的预测值进行对比,结果显示实验数据与低纵横比的软孔模型比较接近。综合考虑基质模量和孔隙形态变化的影响,分析表明在矿物成分变化不大的情况下,样本的等效孔隙纵横比随孔隙度增加有上升的趋势。     

Evaluation of electric parameters of anisotropic sandy-shaly Miocene formations on the basis of resistivity logs

In this paper, electrical properties of an anisotropic rock formation are discussed. Electrical anisotropy parameters, i.e., horizontal resistivity, R _H , and vertical resistivity, R _V , and anisotropy coefficient in the sandyshaly Miocene formation, are determined on the basis of induction logs and laterologs. Graphs of R _V = f(R _H ) calculated for different resistivities of sandstones and shales and variable volumes of those two components allow us to conclude about the correctness of the applied method for determining the resistivity parameters of autochthonous Miocene formations.     

Seismic response of weakly laterally inhomogeneous structure

Summary The seismic response (the transfer properties) of a model consisting of two layers above a homogeneous halfspace, with curved interfaces and continuously laterally varying velocity within the layers is investigated assuming vertical plane SH-wave incidence from below. The frequency response and the synthetic seismograms are computed by the ray and matrix methods. The dependence of the seismic response on the prevailing frequencies of the incident wave, the role of the individual layers in forming the seismic response, as well as the effect of causal absorption are studied.

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含断层破碎带场地对平面SH波的放大作用

借助wolf的土层和半空间精确动力刚度矩阵和斜线荷载格林函数,采用间接边界元法在频域内求解了含断层破碎带场地对SH波的放大作用,着重分析了破碎带较窄断层两侧围岩动力响应的基本规律及场地动力特性对散射的影响.结果表明,断层破碎带对SH波有显著的影响,即使破碎带很窄,也可对SH波产生很大的放大作用;层状场地动力特性对放大作用有显著的影响.     

2.5D scattering of incident plane SV waves by a canyon in layered half-space

This paper presents a 2.5D scattering of incident plane SV waves by a canyon in a layered half-space by using the indirect boundary element method (IBEM). A free field response analysis is performed to provide the displacements and stresses on the boundary of the canyon where fictitious uniform moving loads are applied to calculate the Green’s functions for the displacements and stresses. The amplitudes of the loads are determined by the boundary conditions. The free field displacements are added to the fic...