AMT及TEM在云南某矿山坑道中的应用

为了解决矿山矿坑涌水量大的问题,通过综合分析研究,决定采用AMT (音频大地电磁法)及TEM (瞬变电磁法)两种方法,以便了解该矿坑道内500 m深度范围内具一定规模的含水断裂、破碎带、裂隙等的发育情况,为下一步工程提供指导依据。     

基于瞬变电磁法的金属矿山深部岩体储水分布探测

三山岛金矿邻近渤海,受海水入侵的影响,矿区地下水丰富且水质较差,为保证开采工作的安全进行,需要采用瞬变电磁法对巷道岩体储水分布情况进行探测。介绍了瞬变电磁法的基本原理和工作方法。采用该方法测得三山岛金矿深部巷道岩体富水可能性较强的区域有-765 m中段底板、-780 m中段底板、-780 m中段右帮和-870 m中段底板。采用瞬变电磁法能够准确地定位富水区域,为矿山安全生产提供有效技术依据。     

瞬变电磁法在钻井探测中的应用

该文介绍了瞬变电磁法(TEM)的基本原理及其在钻井探测中的应用。通过工程实例的说明,证实了瞬变电磁法是一种快速,有效的矿山地质物探方法。由于其穿透能力强、分层能力强、受随机干扰小、信息丰富、分辨率较高、探测深度深等特点,使其在矿井深部地区的探测中得到了广泛的应用。     

综合物探在莱州-龙口断裂带金矿资源潜力调查中的应用

在充分收集以往地质、物化探等成果资料的基础上,依据可控源音频大地电磁测深和频谱激电测深工作测制地质-物探综合剖面,识别主要地层单元和局部构造初步揭示剖面地质空间结构和构造形态特征。论述构造特征,丰富矿区构造格架,总结构造特征和矿体富集规律,建立矿体的控矿构造标志,控矿断裂破碎-蚀变带空间展布样式及矿体的产出形态、空间分布,矿体侧伏和尖灭再(侧)现规律。     

瞬变电磁仪及坑内钻在维护采矿权益中的联合应用

自上世纪0年代以来,由于巨额经济利益的诱惑铜坑矿权内的非法采矿作业屡禁不止,对铜坑矿的安全生产及可持续发展造成严重的影响。矿山技术部门创新运用瞬变电磁仪对非法采矿坑道进行探测,查明其具体位置,排除了安全隐患,为企业的的安全生产及可持续发展作出了应有的贡献。     

活性炭测氡及瞬变电磁法在矿山采空区调查中的应用研究

介绍了活性炭测氡、瞬变电磁法两种物探方法在山西小南村矿山踩空区测量效果。讨论了活性炭测氡异常、瞬变电磁法反演断面效果与钻孔验证情况的对应关系。结果表明,活性炭测氡-瞬变电磁法组合测量方法在矿山采空区调查具有较好的应用效果。     

物探技术在矿井地质预测预报中的应用

山西某矿7号煤层回采期间受到不良地质条件影响,其中煤层上覆采空区技术以及陷落柱等均会给采面煤炭安全回采带来制约.若采用钻探或者巷探方式则面临探测范围有限、探测成本高以及效率低下等问题.为此,根据矿井生产面临主要问题,提出综合采用瞬变电磁以及无线电探测技术手段进行超前探测.现场应用后,物探技术可以较为精准地确定富水以及地...     

甘肃省岷县章(哈寨)-包(家沟)金矿地质特征

章(哈寨)-包(家沟)金矿受中三叠统地层近东西向压扭性-韧脆性断裂破碎带的控制。断裂构造是本区矿体最主要的控矿因素,它不仅是矿液运移的通道,而且为容矿提供了有利空间。矿体的形态、规模严格受断裂构造的控制和影响。     

瞬变电磁法在丰山铜矿区找矿预测中的应用

在丰山铜矿区找矿预测中,利用瞬变电磁法(TEM)进行了2条剖面测量,结果表明,瞬变电磁法(TEM)在丰山铜矿研究岩体深部的空间形态、预测成矿有利部位是有效的,可以在有利的地质部位继续开展瞬变电磁法(TEM),使找矿工作取得重大突破。     

扇形探测技术在矿井瞬变电磁物探工作中的应用

为了避免发生突水事故,制定准确高效的水文地质物探措施.云泉煤矿使用YCS1024矿用本安型瞬变电磁仪,通过采用"扇形探测"瞬变电磁法技术对巷道每掘进70 m进行一次多角度、多钻孔的超前物探.最终实现了对掘进头前方(或全侧方)100 m范围内的断层、陷落柱、含水裂隙等局部异常地质体的准确分析.     

断裂韧性与断裂表面分形维数的相关性研究

建立了材料断裂韧性与断裂表面分形维数的相关关系模型。结果表明，断裂韧性是分形维数、材料屈服强度、微结构尺寸及夹杂物体积分数等多参数的函数，并非只取决于分形维数。     

Fracture characteristics of acrylic bone cements. I. Fracture toughness

The vital first phase of the overall materials study to protract the life of the total joint replacements is the identification of the fracture toughness and fatigue properties of bone cements. Information gained from fatigue testing, performed in a manner which simmulates in vivo conditions, and fracture toughness, which is a measure of the propensity of a crack to propagate, is the first step towards the prediction of the life of the total joint replacement. This study is concerned with the fracture toughness of Zimmer and Simplex-P cold-curing bone cements. Following cement fabrication conditions which closely approximate clinical procedures, fracture toughness testing was conducted on cement specimens which were immersed in bovine serum at 37 degrees C in order to simulate in vivo conditions. In addition, a similar study was completed on specimens, tested in air at ambient temperature for purposes of comparison. Results of this procedure, when analyzed by a Student's t-test at the 95% confidence level with eight degrees of freedom, indicate that both Zimmer and Simplex-P exhibit a higher fracture toughness in the simulated physiological environment. In order to determine whether the addition of barium sulfate to these cements compromises the fracture toughness, the above described testing rationale was repeated, indicating the existence of a complicated relationship between the different testing environments and barium sulfate. The importance of these results lies in the fact that an increased fracture toughness indicates that a cement will inherently exhibit a greater degree of resistance to the propagation of cracks, which could contribute to the ultimate failure of the total joint replacement.     

Fracture of the penis

Fracture of the penis is not an uncommon urological emergency. Six patients with this injury, treated at the Institute of Urology, General Hospital, Kuala Lumpur, since 1988, were reviewed. Their ages ranged from 21 to 30 years old (mean 25). Four cases were self-inflicted by abnormal bending and 2 cases occurred during sexual intercourse. A sudden "cracking sound", violent pain, rapid flaccidity and deformity of the penis were documented. Duration of injury at presentation ranged from 12 to 90 hours (mean 35 hours). Primary repair of the tunica albuginea with absorbable suture was performed in all cases. The results of surgery was excellent, with restoration of normal function in 4 patients (2 patients defaulted follow-up). We advocate immediate surgical repair for this injury.     

Fracture at elevated temperature

We have carried out a systematic experimental study of fracture in materials which contain hard second phase particles. The principal variables in this study were the average size and spacing of the second phase particles, grain size, temperature, and the strain rate. Polycrystalline copper containing a dispersion of silica particles was the material used in these experiments. Three modes of fracture were observed: transgranular necking fracture, fracture by the propagation of intergranular cracks initiated at the surface, and intergranular fracture by grain boundary cavitation throughout the entire specimen cross-section. The transition between the fracture modes was shown to shift systematically with temperature, strain rate, and the microstructure. The intergranular fracture mode was studied in detail. The growth of cavities in the grain boundaries was determined to be the rate limiting step in the fracture process. It was determined that in the range of 10^-4 to 10^-7 s-1 in strain rate, the dominant growth mechanism of the cavities was power-law creep rather than diffusional transport. The ductility of the material in the intergranular mode of fracture was found to be strongly dependent on the area fraction of the second phase in the grain boundary and on the strain rate sensitivity of the material; it was weakly dependent on the grain size. A theoretical lower bound and a practical upper bound of the ductility in the intergranular fracture mode were established. The results are in qualitative agreement with the data on nickel-base alloys and other materials published in the literature. formerly a Graduate Student in the Department of Materials Science and Engineering at Cornell University     

Fracture callus in osteopetrosis

The histologic features of bone callus after a traumatic fracture in a patient with osteopetrosis are presented. The fracture callus develops in stages that are apparently normal. The tissue is initially rich in bone-forming cells and vessels. One year later, however, unlike mature osteopetrotic bone, the tissue shows no Haversian organization.     

TRT透平机叶片断裂分析

对某厂2号TRT透平机一级动叶片中断裂叶片的化学成分、宏观断口以及金相组织进行了分析,结果表明,该叶片属于腐蚀疲劳断裂,其疲劳裂纹起源于叶片进气边边缘部位的腐蚀麻点处,腐蚀麻点是由于叶片与湿积灰中的腐蚀性介质Cl-,SO4-等发生反应造成的。     

Method of Evaluating Delayed Fracture Susceptibility of Tempered Martensitic Steel Showing Quasi-Cleavage Fracture

The difference in the hydrogen charging methods, immersion in a NH₄SCN aqueous solution, and cathodic electrolysis in a NaOH aqueous solution, did not affect the hydrogen state present in the steel, but it did affect the surface state of the specimens through corrosion, causing fracture strength to fluctuate in tensile testes. As for stress application method, the fracture strength at lower crosshead speeds in tensile tests was consistent with that found for hydrogen precharging prior to stress application in CLTs as long as hydrogen charging was conducted by cathodic electrolysis. However, the fracture strength obtained with concurrent hydrogen charging without precharging prior to stress application in CLTs was higher than that with hydrogen precharging prior to stress application in CLTs regardless of the same hydrogen content. In other words, delayed fracture susceptibility was affected by the order of hydrogen charging and stress application for quasi-cleavage fracture associated with local plastic deformation, i.e., dislocation motion. Therefore, by taking into account the cathodic electrolysis in the NaOH solution, the low crosshead speed and the order of hydrogen charging and stress application, the fracture strength in CLTs, and tensile tests coincided with respect to quasi-cleavage fracture even though the stress application methods were different.     

Fracture Toughness and Fracture Mechanism of EH47 High-Strength Steel Subjected to Different Temperatures

Metallurgical and Materials Transactions A - The objective of this work was to investigate the effect of temperature on the fracture behavior of EH47 high-strength steel, which is one of the...     

In-Situ Fracture Observation and Fracture Toughness Analysis of Zr-Based Amorphous Alloys Containing Ductile Dendrites

Effects of dendrite size on fracture properties of Zr-based amorphous alloys containing ductile ?? dendrites were explained by directly observing microfracture processes using an in-situ loading stage installed inside a scanning electron microscope (SEM) chamber. Three amorphous alloy plates having different thicknesses were fabricated by varying cooling rates after vacuum arc melting. The effective size of ?? dendrites was varied from 14.7 to 30.1???m in the alloy plates, while their volume fraction was almost constant. According to microfracture observation of the alloy containing fine ?? dendrites, shear bands initiated at the amorphous matrix were connected with the notch tip as they were deepened through dendrites, which led to abrupt crack propagation. In the alloy containing coarser ?? dendrites, shear bands were initiated at the amorphous matrix to form a crack near the notch tip region and were expanded over large matrix areas. The crack propagation was frequently blocked by ?? dendrites, and many shear bands are formed near or in front of the propagating crack, thereby resulting in stable crack growth, which could be confirmed by the fracture resistance curve (R-curve) behavior. This increase in fracture resistance with increasing crack length could be explained by mechanisms of blocking of crack growth, multiple shear band formation, and crack blunting.