X-射线荧光光谱法测定高炉渣和电炉渣中8种常见元素

研究了借助熔片法制样,将高炉渣、电沪渣两种基体建于同一组工作曲线。所获曲线线性良好。分析结果与标准值或湿分析值吻合。     

Stabilization of swelling clays by Mg(OH)2. Factors affecting hydroxy-Mg-interlayering in swelling clays

The damage caused to structures and other human endeavours, on or in the ground, by swelling clay soils is considered as a natural hazard. In order to mitigate this hazard an attempt was made to stabilize the swelling clay mineral structure by the addition of Mg(OH)₂. This will turn the swelling minerals, like montmorillonite, into non-swelling ones, e.g., chloride. Accordingly, the various factors affecting the precipitation-adsorption of the Mg-hydroxide by clays, was investigated, and the conditions giving the best results were established. The factors examined were: the base used as precipitant (NH₄OH and NaOH); the preparation of the precipitate, inside or outside the clay suspension; the sequence and the duration of the reagents addition; the OH/Mg ratio; the time of clay-chemical contact; and the drying time and temperature. The method, was applied to different clay minerals (swelling and non-swelling). The material produced after the Mg-hydroxide precipitation was examined by the methylene blue dye adsorption test, XRD, DTA and DTGA methods; the results were treated statistically by factorial analysis. From the results obtained, it is concluded that the factors affecting the Mg-hydroxide adsorption by clays are: the base used as a precipitant, the preparation of the hydroxide directly inside or outside the clay suspension, the drying temperature, and the rate of titration of the reagents. Therefore, the best conditions for the laboratory preparation of hydroxy-Mg-interlayers are a dilute (1–2%) and well-dispersed clay suspension, pH between 10–12; some 12 meq Mg²⁺, as Mg-salt (e.g., MgCl₂) per gram of clay, added before the base and followed by the dropwise titration of 1–2 N NaOH solution into the clay suspension, to give a molar ratio OH/Mg of about 1.5; vigorous agitation of the suspension during titration of the reagents; centrifugation and decantation of the supernatant liquid, and drying the product at about 250°C. Satisfactory results are also obtained with the fast titration of the base and drying at 105°C to complete dryness.     

零通量方法原位测定给水度

本文简略介绍了零通量面（ＺＦＰ）方法原位测定给水度的原理、计算,并给出了在银北平原江南试区人工调控地下水位条件下和天津万军套洼试点天然条件下应用ＺＦＰ方法原位测定给水度的具体实例。结果表明,给水度测定值与测参历时有关,对单一岩性而言,其值逐渐增大,经过相当时间后将趋于某一稳定值,其原因是非饱和带释水存在滞后作用,所以它也是反映不同释水过程的一个参数,其值是在一个范围内变化。另外给水度测定值与包气带及潜水位变动带的岩性有关,土层质地越粘重给水度值越小,包气带释水的滞后作用影响越明显。同时,潜水位降落的起始位置不同对多层地质结构的给水度测定值影响也不同。而且给水度的测定值还与潜水埋深及包气带土壤剖面初始含水量有关。     

内陆河高寒山区流域分布式水热耦合模型（Ⅰ）：模型原理

在全球变暖的背景下，我国多数大江大河源区存在冰川退缩、雪线上升以及多年冻土和季节冻土明显退化等现象，并由此造成河源区产流量减少以及生态环境恶化等诸多问题，这在内陆河山区流域体现的较为明显，但目前分布式水文模型中很少涉及冻土水热耦合问题。文章以黑河干流山区流域为例，构建了一个内陆河高寒山区流域分布式水热耦合模型（DWHC）。模型基于土壤水热连续性方程将流域产流、入渗和蒸散发过程融合起来，在植被截留、入渗、产流和蒸散发计算方面也有所改进和创新，部分模块具有多个可选择方案。模型设计了与中尺度大气模式MM5的嵌套接口，也可以用地面气象资料驱动。模型在1 km×1 km网格基础上，以日为时间步长，将流域土壤分为18类，土壤剖面分为3～5层不等，流域植被概化为9类。模型只需要土壤初始含水量、初始地温和常规气象资料，以及土壤和植被物理参数，就能够连续演算各层土壤的温度、液态含水量、固态含水量、感热传导、潜热变化、水势梯度、导水率以及水分入渗和毛细上升量等水文循环要素。主要介绍了模型的基本原理和构建思路，有关模型的地面资料驱动结果和与MM5嵌套结果部分，参见后续文章(Ⅱ)、(Ⅲ)。