地质及采矿设计过程中的几点体会

地质及采矿设计是矿山设计过程中的关键部分,它包含仔细研读原始地质资料、圈定开采境界、绘制水平分层平面图及采掘终了平面图、计算储量及剥采比、编制采剥进度计划表等,此部分的设计文件是矿山正常生产过程中的重要指导性文件。作者从自身的设计经历出发,较为详细地介绍了各环节设计过程中所应注意的技术问题,并指出了当前设计时所面临的困难,以及目前传统设计方法所面临的不足,最后结合当今国内外采矿设计的形势,对将来的发展方向进行了展望。     

硫酸盐渍土含水率单次递减条件下的盐胀特性

为探究硫酸盐渍土在含水率递减下的盐胀特性,通过自主设计的试验装置,在室内开展了11组含水率单次递减下的盐胀试验,共历时2 868 h。结果表明：在含水率单次递减下硫酸盐渍土的起胀含盐量约为1.2%。含盐量<1.2%时,土体干缩,干缩量与含盐量近似呈下凸的二次抛物线规律,且干缩峰值含盐量约为0.5%;含盐量≥1.2%时,土体膨胀,且盐胀率与含盐量近似呈线性增大规律。盐胀敏感含水率区间受含盐量影响很小,含盐量从1.5%增至4.0%,盐胀敏感含水率区间基本稳定。此外,含水率递减速率与含盐量呈负相关规律,同一含盐量的硫酸盐渍土,其含水率的递减速率随含水率的降低亦减慢。基于以上试验结果,进一步开展了4组单次降温下的盐胀对比试验,结果表明：含盐量升高时,起胀温度区间逐渐升高,盐胀敏感温度区间的区间范围逐渐扩大。单次降温下的盐胀率均高于含水率单次递减下的盐胀率,且随着含盐量的升高两试验条件下的盐胀率差值趋于一常数。研究结果对西北地区高含盐量的残余型硫酸盐渍土地基的盐胀性评价具有重要指导意义。     

陕北榆林地区舒适性空调空气处理方案分析

分析了当地的气候条件,提出应因地制宜的合理确定舒适性空调空气处理方案及空调形式。并结合榆林地区已有的空调工程经验,提出常用空调方案设计中应注意的事项,并对其设计及运行工况加以阐述与分析。     

MDD模式与快速冷却事件

ＭＤＤ 模式（Ｍｕｌｔｉｐｌｅ Ｄｉｆｆｕｓｉｏｎ Ｄｏｍａｉｎ ｍｏｄｅｌ） 是Ｄｏｄｓｏｎ 模式的扩展,它可以从一个钾长石样品分析中,得到温度在≤３５０ ～１５０ ℃之间的一条连续的冷却曲线,因此,ＭＤＤ 模式的一个突出贡献是对快速冷却事件的定量制约。冈底斯岩带与哀牢山－ 红河剪切带中新世的快速冷却事件与构造含义是利用这一模式进行研究的成功实例,它不仅定量厘定了快速冷却事件的时间,证实了其存在的普遍性,而且明确指出了中新世印度和欧亚板块碰撞后岩石圈质量转移过程的时间序列,定量地指出了冈底斯岩带逆冲抬升导致的地壳增厚与沿哀牢山－ 红河剪切带地壳块体的侧向挤出在时间上的同步性和差异性     

岩浆成矿体系的热演化和剥露史的数字模拟

通过对岩浆冷却过程的数字模拟研究,揭示出岩浆在冷却成矿过程中的温度分布和变化规律及影响因素．在此基础上,进一步应用高精度的温龄计组合来限定岩浆成矿体系的热演化和剥露历史,精确地计算出岩浆的初始侵位时间和深度、矿物结晶时间、冷却速率、冷却和暴露地表时间,以及剥露和剥蚀速率等重要参数,并将模拟结果应用于斑岩铜矿床的成矿研究中．研究表明,将精确的年龄测试手段与计算机模拟技术相结合,可为定量研究岩浆矿床的热演化和剥露史、深入了解矿床的成因机制提供一种有效方法．     

P–T–t paths and post-metamorphic exhumation of the Day Nui Con Voi shear zone in Vietnam

The Day Nui Con Voi belt in Vietnam is the southeasternmost part of the Red River shear zone in Asia. It is a narrow high-grade metamorphic core complex consisting of garnet–sillimanite–biotite gneisses, mylonite bands, amphibolite layers and migmatites. Geothermobarometric study of the complex revealed that the peak metamorphism took place under amphibolite-facies conditions of 690₋₆₀⁺³⁰°C and 0.65±0.15 GPa and the subsequent mylonitization occurred under greenschist-facies conditions of 480°C and under 0.3 GPa. Fifteen synkinematic hornblende and biotite separates from gneisses, amphibolites and mylonites were dated with the K/Ar method. Hornblende separates from the Day Nui Con Voi give K–Ar ages of 26.4–28.5 Ma, and the biotite separates do give 24.5–24.7 Ma. Combination of thermobarometric and geochronological data yields the cooling history of 500°C at 28 Ma and 300°C at 24 Ma with a cooling rate of 70–110°C Ma⁻¹, and 23 km post-metamorphic exhumation of the core complex. The first 16 km exhumation from the peak of metamorphism (at probably 31 Ma) to 28 Ma was triggered by the left-lateral strike-slip displacement of the Red River shear zone.     

郯庐断裂带(安徽段)内磁铁石榴角闪岩的形成条件、年代学及构造归属的探究

通过对肥东群南缘特征性岩石——磁铁石榴角闪岩的构造地质学和岩相学研究表明,磁铁石榴角闪岩及其围岩以构造透镜体形式产出,该变质岩具有两个阶段变质矿物组合,热力学评价显示①阶段的温压范围为：T=616~700℃和P=0.66~0.85GPa,平均温压为T=653±35℃和P=0.75±0.09GPa。②阶段的温压范围为：T=597~643℃和P=0.51~0.94GPa,平均温压为T=620±15℃和P=0.73±0.15GPa,并表现出一个快速等压降温P-T演化特征。锆石U-Pb定年和拉曼光谱分析表明,该磁铁石榴角闪岩的变质年龄为2469±49Ma。结合地质背景和前人的研究,可以判定该类岩石可能源于华北板块。由于郯庐断裂的左旋走滑作用被构造并置与扬子板块中。从而进一步推测,郯庐断裂（安徽段）横向宽度可达到10~15km。     

Geothermobarometry of mafic granulites and metapelite from the Palghat Gap, South India: petrological evidence for isothermal uplift and rapid cooling

The Palghat Gap region is located near the centre of the large southern Indian granulite terrane. at the northern edge of the Kodaikanal charnockite massif. The dominant rock types in the region are hornblende-biotite ± orthopyroxene gneisses and charnockites along with minor amounts of intercalated mafic granulite, metapelite and calc-silicate. The P-T estimates from garnetiferous mafic granulites and metapelite samples are generally in the range 9-10 kbar and 800-900 C using both conventional thermobarometric methods and the TWEEQU thermobarometry program. These P-T estimates, which should be taken as minimum values, are among the highest yet reported for South Indian and Sri Lankan granulites. The occurrence of orthopyroxene + plagioclase symplectites around embayed garnet grains in the mafic granulites and cordierite rims around garnet grains in metapelite suggest an isothermal decompression-type path. Similarly, a core-rim P-T trajectory indicates c. 3 and 7 kbar decompression at high temperature in the mafic granulites and metapelite, respectively. In both rock types, the key to the determination of the retrograde P-T path was the recognition of small amounts of second generation plagioclase with a more anorthitic composition than the matrix plagioclase. The preservation of high garnet-pyroxene temperatures in the mafic granulites (despite small garnet grain size) suggests rapid cooling of the terrane. Calculated minimum cooling rates range from 8 to 80 C Ma^-1. Such cooling rates are more rapid than those associated with normal isostatic processes and suggest that the terrane was tectonically exhumed at high temperature.     

Effects of Volcanic Ash on Computers and Electronic Equipment

Computers and electronic equipment are an important component of the infrastructure of our modern environment. It is therefore essential that we know the effects of volcanic ash on such equipment. This paper presents the results of a pilot study to test computers and cooling fans in an ash-charged environment to assess their vulnerability. In the experiment, ash was poured on to computers and cooling fans in a sealed 0.216 m³ perspex box, with the effects on both the ash and the equipment monitored. Three different types of ash (1996 Ruapehu andesitic ash, Sakurajima andesitic ash and Kaharoa rhyolitic ash) were used in the experiments.In the first experiment each type of ash was photographed by Scanning Electron Microscope (SEM), then passed through the bearing unit of a cooling fan and photographed again afterwards. The bearings within the cooling fan continued to work even after 720 h of testing and there was no significant abrasion of the fan-shaft bearing. The ash was however fragmented, suggesting that the brittle ash shattered to fine dust, which caused significantly less abrasion to the bearings or shaft than expected. Three computers were then tested in the sealed box. Ash was introduced at increasing rates to simulate catastrophic entry of ash into a work environment, and computers were tested throughout using the BURNIN^® testing programme. Failure times ranged from 100 to 150 h; most failures occurring when humidity was increased by spraying water mist into the airflow. If dried out the computers continued to operate again if failure was not catastrophic. Card slot edge connectors proved to be one of the weakest links, as a bridge of ash formed across the gap. They were also subject to abrasion with some of the gold plating being removed. This did not however cause operating difficulties.The conclusions are that computers are more resilient than originally thought, unless the ash is moist. Simple low-tech procedures should be adequate to protect computers from small amounts of dry and moist ash contamination.     

封闭条件下抛石路堤降温效果及机理的试验研究

在多年冻土地区道路工程的修筑与维护中, 如何保证多年冻土不退化所采取措施的长期可靠度问题日益为人们所关注. 通过室内试验研究了实际工程中半开放半封闭抛石路堤受到风沙或积雪填埋后,在不同温度变幅条件下的降温效果. 实验结果发现: 在满足一定厚度时, 封闭条件下的块石层仍具有良好的降温效果, 具有可变等效导热系数的特性, 在实验中充分体现了"热二极管效应". 在外界温度变幅较大的条件下, 降温速度和降温效率均大于温度变幅较小的情况. 通过对块石层顶底温差与其顶部温度变化关系, 以及块石层内温度场特征的分析, 证实了封闭块石层内自然对流的真实存在和对流的运动发展趋势. 试验结果为抛石路堤降温的长期可靠性提供了依据.