载炭泡塑吸附-电感耦合等离子体发射光谱法测定金矿石的金量

载炭泡塑吸附法对金有良好的吸附性能,但只能用于抽滤吸附不能振荡吸附,分析手续繁杂。本文以载炭泡塑振荡吸附-电感耦合等离子体发射光谱法测定金矿石的金量。样品在650℃高温灼烧2 h,用50%王水和10%氯化铁加热溶解,溶液冷却后加入5%高锰酸钾氧化,用中密度规格的载炭泡塑两次振荡吸附溶液中的金,然后于580℃高温灼烧后以50%王水溶解灰分,直接用ICP-OES测定金量。方法检出限(3σ)为0.002μg/g,精密度(RSD,n=11)小于3.7%。本方法对金的吸附率大于99.9%,测定范围为0.01~90μg/g,对不同类型金矿石的适应性强,解决了以往泡塑吸附法吸附率较低、标准系列与样品需同时预处理的问题,对低含量和高含量样品均有较高的准确度。     

俯冲带地震诱发机制:研究进展综述

俯冲带作为地球循环体系的关键部位,具有构造活跃、地震多发以及地质条件复杂等特征。基于震源位置,俯冲带地震既可划分为板间和板内地震,也可分为浅源、中源和深源地震。俯冲带内的浅源地震包括板间地震和浅源板内地震,而中源和深源地震皆属于板内地震。在地球浅部,温度与压力低,浅源地震是由岩石发生脆性破裂或沿着先存断层发生不稳定摩擦滑移造成的。随着深度增加,温度和压力的增加使得流行于浅部的脆性和摩擦行为在无水条件下被强烈抑制,岩石从而表现为可抑制地震的韧性行为,使得中-深源地震的诱发机制有别于常规的脆性行为。随着研究的逐渐深入,人们了解到中源地震的诱发机制主要是脱水或与流体相关的致脆以及塑性剪切失稳,而深源地震的成因主要是相变致裂。然而,中-深源地震很可能是两种或两种以上机制共同作用的结果。例如,在中源深度既可能是流体相关的致脆导致脱水源区的脆性围岩产生地震,亦可能是脱水的蛇纹岩本身可能在流体孔隙压的作用下作粘滑滑移,而前者比后者更为重要。孕震带宽度大于"反裂隙模型"预测的亚稳态橄榄石冷核宽度的深源地震可能是由第一阶段的相变致裂和第二阶段的塑性剪切失稳诱发,而孕震带的实际宽度与预测宽度相当的深源地震则可能仅由相变致裂引起。只要过渡带内名义无水矿物中的结构水能释放出来,脱水致脆同样可能触发一些深源地震;而塑性剪切失稳不仅能在中-深源地震触发后的扩展阶段起着主导作用,而且还能单独触发一些中-深源地震,因此能够解释大多数反复发生的中-深源地震活动。     

东昆仑造山带东段哈图沟–清水泉–沟里韧性剪切带塑性变形及动力学条件研究

东昆仑造山带东段哈图沟–清水泉–沟里韧性剪切带记录了多个旋回的造山作用,本文通过对韧性剪切带中石英c轴组构和显微构造特征测试分析,探讨东昆仑造山带东段陆块间俯冲拼合及地壳伸展减薄的形成机制。结果显示,韧性剪切带变形温度介于380~650℃之间,形成环境为中–高绿片岩相到低角闪岩相,剪切带内差异应力值介于173~509 MPa之间,应变速率介于6.93×10–14~1.43×10–8 s–1之间,主体为10–11~10–10 s–1,显示韧性剪切带变形是快速俯冲作用下的产物,越靠近东昆仑造山带东段东昆中断裂带其变形温度、差异应力值及相应的应变速率值越大,表明东昆仑造山带东段韧性剪切变形中心为东昆中断裂带。利用不同方法所计算出的韧性剪切带运动学涡度值,显示韧性剪切带早期瞬时运动学涡度(0.56~1)对应于东昆仑造山带东段东昆南与东昆仑造山带东段东昆北陆块间俯冲的初始阶段,中后期运动学涡度(0.25~0.91)应当对应于东昆南与东昆北陆块间的俯冲碰撞阶段,最晚期的C′瞬时运动学涡度(0.19~0.51)则对应于后造山的伸展阶段。通过石英c轴组构结合其宏微观构造特征,认为东昆中构造带至少经历了3个期次的构造运动,分别为加里东晚期的逆冲兼左行走滑剪切作用、晚海西–印支期的逆冲兼右行走滑剪切作用和燕山早期及之后的脆韧性–脆性的左行走滑剪切作用。     

Experimental evaluation of shear strength behaviour of plastic and non-plastic silts

Silt is available in many parts of the world in combination with sands and clays. However, due to lack of clear understanding of its engineering behaviour, most of the time it is interpreted in terms of either sands or clays. Structures that are usually built on silty soils are designed to take into account design procedures developed for sandy or clayey soils. Presence of silts in combination with varying amount of sand and clays produces silt that is either plastic or non-plastic in nature. Silt is available in and around the Delhi region, in a majority mixture along with fine sands, which is non-plastic in nature. On the other hand silty deposits found in offshore Bombay High region are found in abundance along with significant amounts of clays and are termed as plastic silts. In this paper a comparison of the stress-strain behaviour of plastic and non-plastic silts is carried out under triaxial compression loading during both drained and undrained conditions. Two representative samples each from Delhi and Bombay High regions were considered for this comparison and results of stress-strain under four sets of confining pressure are discussed in detail. It is observed from this study that behaviour of silts is mainly dependent on the composition and structure of the resultant soil matrix. It is concluded from the results that shear strength parameters as well as volume change/pore pressure response of silty soils is dominated by the constituent soil present along with the silt. It is seen from the comparative behaviour of non-plastic and plastic silts that the presence of sand and clays has a governing effect on pore pressure development and the resultant friction angle. The study also corroborated that the nature of silt is transitional both in the case of plastic and non-plastic forms.     

应用塑性图对陕西特殊土的判别

塑性图是由卡萨格兰德（Ａ·Ｃａｓａｇｒａｎｄｅ）于１９４２年首次提出的，该图将阿太量（Ａ·Ａｅｔｅｒｂｅｒｇ）界限（液限、塑限）应用于土质分类．本文根据塑性图判别理论并应用塑性图，对陕西省特殊土（黄土、三趾马红土、膨胀土等）进行了判别，结果为黄土位于ＣＬＹ区，三趾马红土和膨胀土位于ＣＨＥ区，其效果较好，达到了分类的目的．     

玉林冬季免耕马铃薯分期播种试验及优质高产气候分析

对玉林市主栽的马铃薯品种黑龙江K 3紫花,采用稻草免耕、地膜覆盖和常耕栽培三种栽培措施分五次播种进行试验,表明,稻草免耕技术不但对地面温度、土壤湿度有很好调节功能,而且与地膜覆盖和常耕栽培产量差异达极显著水平。以播期为11月30日的产量最高,播期为12月10日产量最低。     

基于广义热力学的超固结土本构模型

基于广义热力学基本理论,通过考虑塑性剪切变形产生的能量一部分以塑性自由能的形式储存,并且该部分自由能与超固结度相关,结合修正剑桥模型的热力学函数形式建立了适用于超固结土的自由能函数和耗散函数。该耗散函数与当前应力状态无关,相关联流动法则仍然适用。由建立的耗散函数和自由能函数,推导了弹塑性本构关系的屈服函数、流动法则、硬化定律。通过4种不同超固结土的试验结果和计算结果进行比较,验证了模型的合理性。     

A semi-empirical dilatancy model for ballast fouled with plastic fines

In the era of high speed trains, it is very important to ensure the stability of rail tracks under adverse conditions including the fouling of ballast. Fouling of ballast from unstable and saturated soft subgrade soil is one of the major reasons for track deterioration. The reported results of a number of large-scale laboratory experiments on the shear behaviour of ballast and fouled ballast are analysed, herein. It was observed that fines have a significant influence on the shear behaviour of ballast. Shear strength increases and dilatancy decreases with the addition of fines. In this paper, a semi-empirical mathematical model has been proposed to capture the dilatancy of ballast fouled with fines during shearing. The empirical constants a, b and c proposed in the model are a function of the fines content Void Contamination Index (VCI). The results of the model have been compared with the laboratory experiments and are found to be in good agreement.     

利用三山岛金矿尾矿制备塑料母料

经磨矿作业后,金矿选别过程通常会产生大量细粒尾矿,三山岛金矿尾矿堆存量较大,尾矿资源丰富。尾矿中有价元素含量不高,尾矿中丰富的非金属矿资源尚未得到有效回收利用。本文以三山岛金矿尾矿为主要原料,进行了有价元素回收探索研究、分级提纯研究、表面改性研究以及制备PP,PE母料添料的试验研究。将分级提纯后的尾矿作为碳酸钙替代料制备的PP,PE母料添料具有良好的性能指标,实现节能减排,减轻环境负担的同时,减少橡胶原料的消耗。     

岩石圈塑性流动与大陆板内构造变形研究进展评述

人们对大陆板内构造变形机制有两种不同认识,即“刚性”板块通过弹性实现应力远程传递和岩石圈通过下层塑性流动实现应力远程传递。通过对岩石圈各层变形属性和塑性流动的研究。认为通过处于塑性状态的下地壳和岩石圈地幔的塑性流动实现应力远程传递和控制板内构造变形更为合理。