控制热力学条件下的矿物、岩石电学性质研究

电导率是重要的地球物理参数。模拟地球内部条件下的矿物、岩石电导率测量是了解地球内部物质组成及物理化学性质的有效手段，同时，还可以为野外大地电磁测量结果的解释提供依据。在YJ-紧装式六面顶压机上，对原有的矿物、岩石电性测量系统进行了进一步的改进；建立了一套以Solartron 1260阻抗／增益一相位分析仪为测试仪器，使用Mo电极和Mo盾来控制样品氧逸度的测量系统，该系统的氧逸度环境为Mo-MoO2，接近Iw缓冲对。石英（人造水晶）、橄榄石、纯橄榄岩、辉石岩、二辉橄榄岩、巨晶辉石的电导率测量是在新的测量系统下获得的，而辉长岩的电导率测量是基于LCR仪为测量仪器的测试系统下获得的。在压力为1-3GPa、温度为675K-160OK、频率为106-0.1Hz、氧逸度为Mo-MoO2的条件下，对不同方向石英（人造水晶）的电学性质进行了研究。复阻抗平面上出现了反映样品本身性质的阻抗弧和反映样品与电极之间扩散的直线。石英的电导率随温度增加而增加，随压力的变化比较微弱。石英的导电机制主要为离子导电，载流子可能为碱金属离子和氢离子，这些碱金属离子和氢离子主要在平行于光轴的通道中运动。在相同的温度和压力条件下，a石英的电导率和c轴的夹角有关，石英的电导率随着夹角的增大而减小，表现出了强烈的各向异性。对“各个方向石英在发生了相变前后的电导率进行了研究，发现Q石英转变为p石英后，电导率并没有突变，仍然随着温度的增加而增加。在压力为1-2GP。、温度为563-1173K、频率为12-105Hz的条件下研究了辉长岩的阻抗。结果发现辉长岩复阻抗的实部随频率的增加而减小，而虚部随频率增加先增大后减小；相角随频率增加而减小。在复阻抗平面上出现了反映颗粒内部的阻抗弧，该阻抗弧出现在高频段。实验室获得辉长岩在地壳的压力和温度（1.0GP。和893K）条件下的电导率值为1.77×-4S／m，而高导层的电导率值为0-01-0-15S／m，二者相差了2-3个数量级，推断辉长岩不能在下地壳形成高导层。在压力为3.0GPa、温度为1299-1600K、频率为106-0.1Hz、氧逸度为Mo-MoO2条件下，对不同颗粒粒度的橄榄石电导率进行了测量。在复阻抗平面上均出现了反映颗粒内部电响应的阻抗弧，这些阻抗弧随着温度的增加而减小。而反映颗粒边界导电机制的阻抗弧并不明显，两种阻抗弧出现在不同的频率范围内，反映颗粒内部导电机制的阻抗弧出现在频率较高的范围内，而反映颗粒边界导电机制的阻抗弧出现在频率相对低的范围内。不同粒度橄榄石在3.0GPa条件下的电导率随着温度的增加而增加，它们的激化烩介于1.03-2.11ev之间。在压力为1-3GPa、温度为1282-1544K、频率为0.1-106Hz、氧逸度为MO-MoO2的条件下，对纯橄榄岩的电导率进行了测量。在复阻抗平面上出现了反映颗粒内部电响应和颗粒边界电响应的阻抗弧。反映颗粒内部导电的阻抗弧出现在较高的频率段，随着温度的增加，这些阻抗弧逐渐收缩。颗粒边界的阻抗弧出现在相对低的频率段。纯橄榄岩的电导率随着温度增加而增加，随压力变化比较微弱。对颗粒边界的电导率研究表明，颗粒边界的电导率高于颗粒内部的电导率，总电导率则小于颗粒内部和颗粒边界的电导率，颗粒边界并没有增强总电导率。纯橄榄岩的激化能为1，62eV，而激化体积为0.67cm3／mol，指前因子为5125加。利用实验所获得的拟合参数，建立了地球内部200-40Okm处的电导率模型，并同地球物理模型进行了对比，在温度和氧逸度的合理波动范围内，实验室电导率模型和地球物理模型吻合的很好。在压力为1-2GPa、温度为1228-1584K、频率为0.1-106Hz、氧逸度为MO-MoO2条件下，测量了天然和热压辉石岩、热压巨晶辉石、二辉橄榄岩的电导率。结果发现，在复阻抗平面上出现了反映颗粒内部电响应和颗粒边界电响应的阻抗弧，反映颗粒内部导电的阻抗弧出现在较高的频率段，随着温度的增加，这些阻抗弧逐渐收缩。颗粒边界的阻抗弧出现在相对低的频率段。辉石岩、二辉橄榄岩、巨晶辉石电导率随着温度增加而增加，随压力变化比较微弱。天然辉石岩和热压辉石岩颗粒边界的电导率高于它们各自颗粒内部的电导率，而总电导率则小于颗粒内部和颗粒边界的电导率，颗粒边界并没有增强总电导率。辉石岩一二辉橄榄岩一纯橄榄岩的电导率依次减小，这可能是与它们的铁含量有关。天然辉石岩的电导率与热压辉石岩的电导率的差异可能与样品中的水（氢）含量的不同有关。

Asesoría para el rescate de producto y técnicas tradicionales y mejoramiento artesanal actual a partir del perfeccionamiento de la talla en madera en la comunidad Emberá Duma de Bahía Solano - Chocó.

30 hojas : ilustraciones, fotografía.

A Sermon occasioned by the death of Mrs. Sarah R. Baker

Funeral sermon

Análisis didáctico y formación inicial de profesores: competencias y capacidades en el aprendizaje de los escolares

En este trabajo precisamos el significado de los términos capacidad y competencia en el marco de un programa de formación inicial de profesores de matemáticas de secundaria. Describimos brevemente las bases de ese programa y, a continuación, presentamos y ejemplificamos un procedimiento mediante el cual los futuros profesores reflexionan en torno al aprendizaje de los escolares y usan esas nociones cuando abordan la planificación de una unidad didáctica.

A comprehensive copper stockpile leach model: background and parameter sensitivity

The design and development of a comprehensive computational model of a copper stockpile leach process is summarized. The computational fluid dynamic software framework PHYSICA+ and various phenomena were used to model transport phenomena, mineral reaction kinetics, bacterial effects, and heat, energy and acid balances for the overall leach process. In this paper, the performance of the model is investigated, in particular its sensitvity to particle size and ore permeability. A combination of literature and laboratory sources was used to parameterize the model. The simulation results from the leach model are compared with closely controlled column pilot scale tests. The main performance characteristics (e.g. copper recovery rate) predicted by the model compare reasonably well with the experimental data and clearly reflect the qualitiative behavior of the process in many respects. The model is used to provide a measure of the sensitivity of ore permeability on leach behavior, and simulation results are examined for several different particle size distributions.

Measurement Of The Responses Of Individuals To Environmental-Stress And Pollution - Studies With Bivalve Mollusks

Certain physiological differences between individuals in different populations of the mussel, Mytilus edulis, are described. In particular, the scope for growth differs in space and time and may be used to assess the animals' physiological condition. When the required measurements are made in the field, the rates of growth predicted from the physiological data agree well with observed rates of growth. An alternative approach utilizes mussels transplanted to various waters, with indices of condition then measured in the laboratory under standard conditions; an example of this approach is illustrated. Laboratory experiments are used to equate various levels of physiological condition with fecundity, in an attempt to equate physiological effects on the individual with likely population damage. A cytochemical index of stress is described, based on the latency of lysosomal enzymes; spatial variability in this index, and its relation with the scope for growth, are discussed. Finally, the results of some experiments on the effects of petroleum hydrocarbons on mussels are described and the presence of inducible activity of NADPH-dependent tetrazolium reductase in the blood cells is demonstrated. Certain considerations that apply in adopting similar measurements of biological effects of pollution in environmental monitoring programmes are discussed.