哈德门金矿区矿体定位规律研究

通过对哈德门金矿区工业矿体的空间展布特征和金矿化富集规律的研究，揭示了工业金矿体的空间定位规律及其特征。     

厄瓜多尔Colorado v金矿区成矿规律及找矿标志研究

文章初步概括了厄瓜多尔艾尔奥罗省Coloradov矿区金矿床的地质特征,并进行了成矿阶段研究,总结了成矿规律和找矿标志。Coloradov矿区位于厄瓜多尔西南地区的构造-岩浆岩带中,通过分析其成矿地质背景,划分出六个主要的蚀变及成矿阶段,总结概括了该矿区的典型成矿地质特征,确定其矿床类型为斑岩型金矿床。从矿化富集规律、蚀变矿化分带规律、构造控矿规律和岩体控矿规律四个方面阐述了该矿区成矿规律。最后提出了该矿区的六个找矿标志,用以指导下一步探矿工作。     

广东河台金矿矿体赋存规律及找矿前景

在分析成矿地质背景和矿区地质特征的基础上,提出了糜棱岩带赋存工业矿体的条件．总结了矿体矿化富集规律和产出特征,通过对金矿体赋存规律的研究,并结合物探、化探和遥感等找矿方法,在生产区及矿区外围提出了5处具有较好找矿前景的远景区。     

哈达门地区金矿成矿规律及找矿方向研究

本文在探究哈达门地区区域地质概况的基础上,探究了该地区地层构造、岩浆活动、区域地球物理地球化学特征等成矿区域的地质背景,并针对哈达门沟金矿区金矿地质特征进行深度分析,最后探究了该矿区金矿床成矿的地层控矿规律、构造控矿规律和岩浆岩控矿规律,为哈达门地区金矿寻找标志的有效归纳总结和找矿远景的深度探讨提供重要依据,更为哈达门...     

不同天气条件下地下金属管线探测数据误差特征分析

为了研究在不同天气条件下地下金属管线的探测数据误差和变化规律,提出了不同天气条件下地下金属管线探测数据误差特征分析这一课题。分别在晴天、多云天气和雨天里,对金属管线探测导电性数据误差特征、定位数据误差特征和信号干扰数据误差特征进行分析,得出一定的结论和规律,就以上得出的结论和规律进行探讨。     

曹家埠金矿区成矿机理与找矿前景

本文在曹家埠金矿区经过多年探采总结的地质编录基础上,简单介绍了曹家埠金矿区的矿床地质特征,分析了矿体成矿规律与找矿标志.并重点论述了该区的控矿构造特征,赋矿规律,说明了今后的找矿方向.     

离子型稀土矿地球化学特征与物性研究

离子型稀土矿是中国重要的战略关键金属资源,其特殊的成矿特征与稀土元素赋存机制导致矿床地球化学特征、矿石理化性质及元素分布规律等特性复杂,制约了离子型稀土资源的高效开发利用.本文以江西赣州离子型稀土矿为研究对象,系统研究了矿床地球化学特征、稀土元素空间分布规律及矿石物性特征,结果表明江西赣州地处亚热带丘陵地带,气候特征与...     

甘肃成县毕家山铅锌矿床成矿规律探讨

通过对毕家山铅锌矿的矿床地质特征及探采实践成果资料的研究和对比,总结出了矿床成矿规律,并且论述了矿床成矿规律在矿山生产探矿及采矿过程中的实用意义。     

曹家埠金矿床构造控矿规律与找矿预测

在曹家埠金矿床经过多年探采总结的地质编录基础上,简单介绍了曹家埠金矿区的矿床地质特征。从矿脉的空间分布,矿体形态、产状、规模,矿体与围岩的关系,矿石结构、构造,矿石类型,矿石的矿物成分和化学成分、变质作用和围岩蚀变、矿化阶段划分和矿床成因等方面综合论述了该矿床的地质特征,并对矿床成因进行了初步研究探讨。同时分析了矿体成矿规律与找矿标志,并重点论述了该区的控矿构造特征、赋矿规律。通过对曹家埠及其平里店周围的矿床、矿点多年的探采工作,对这类金矿床的控矿构造规律有了新认识,为矿区开展深部和外围探矿,提供了一套合理的找矿方法和理论。     

河西金矿区裂隙密集蚀变带成矿规律研究

通过对河西金矿区裂隙密集蚀变带内构造特征、矿化信息的分析研究,查明了各级控矿构造的空间展布特征、控矿规律,归纳总结了裂隙密集蚀变带的成矿规律,为进一步的成矿预测提供了依据。     

循环水磁防垢除垢作用机理及影响因素分析

结垢是工业循环冷却水普遍存在的现象,为了研究循环水磁防垢除垢作用的机理,通过文献调研前人对循环水磁防垢的相关研究,总结了磁处理水理化性质(黏度、表面张力和氢键数量)的变化以及水垢(文石、方解石)结构的变化与系统能量的关系,并结合影响磁化水抑垢效果的因素,针对目前对于磁防垢除垢作用机理的分歧,从相关的试验结论出发,以能量为落脚点对循环水磁防垢除垢作用的机理进行了推导,即水分子经磁场作用后,增加了氢键数量形成了更多的水合离子,减少了水垢的形成,同时致使体系能量降低和活化能增加,而活化能的增加能够促进硬垢向软垢的转变。这种经磁场作用后体系能量的重新分配造成的变化解释了常见的磁处理结论,并就影响磁处理阻垢效率的因素进行了讨论。     

考虑油膜阻力的直线滚动导轨副摩擦力建模与试验

为了准确预测直线滚动导轨副的摩擦力大小及受影响因素,本文考虑导轨副的流体润滑状态,基于Hertz接触理论研究了直线导轨副摩擦力受滚珠接触角和预紧力的影响规律.基于接触理论建立了直线导轨滑块的受垂直载荷的静力学平衡方程.利用Hertz接触理论分析直线滚动导轨受外力时各列滚珠接触力的变化情况,并结合对临界载荷的分析,建立了随外载荷变化的考虑润滑油膜阻力的直线滚动导轨副摩擦力模型.以国产某型号直线滚动导轨副为研究对象,对所建立的受载摩擦力模型进行试验验证.通过试验数据与理论数据的分析和对比,验证了润滑油膜阻力、接触角和预紧力等因素对直线导轨副摩擦力的影响规律.研究表明,直线滚动导轨副摩擦力在润滑条件下,受接触角变化和预紧力退化的影响呈现有规律的变化.      

连铸方坯中心线凝固行为波动现象及变化规律

连铸坯中心线区域钢液的凝固行为与中心偏析缺陷的形成及控制密切相关。基于中碳钢连铸方坯纵断面的实际凝固组织,以中心偏析点内部二次枝晶间距计算局部冷却速率,揭示了铸坯中心线局部冷却速率的波动特征。结合连铸三维凝固模型,研究了铸坯中心线固相率波动引起局部冷却速率波动并最终影响铸坯中心组织和性能的均匀性的机理;对不同工况铸坯中心线固相率和局部冷却速率波动的周期性进行了分析对比,提出了连铸坯凝固终点位置的周期性波动机理并得到了不同拉速下凝固终点波动距离的判断方程,对于所选连铸方坯,凝固终点波动距离为25.0～27.5 mm;在此基础之上,研究了拉速对中心线固相率波动程度的影响规律,并分析了凝固终点波动距离变化对末端电磁搅拌(final electromagnetic stirring, F-EMS)和轻压下(mechanical soft reduction, MSR)作用均匀性的影响。结果表明,拉速由1.8 m/min提高至2.4 m/min后,虽然液相穴长度增加可能增加整体偏析程度,但铸坯中心线固相率波动程度降低了20%,这有利于减轻中心线偏析沿拉坯方向的波动性,提高铸坯中心质量的均匀性。并...     

复合剪刃滚筒飞剪开发应用

作为板带材连续生产线上的关键设备,飞剪的剪刃侧隙调整精度直接影响了剪切质量,带材越薄对剪刃侧隙的精度要求越高,带材越厚对设备的冲击越大。本文将剪刃侧隙精度高的直剪刃和可减弱冲击的螺旋剪刃耦合在同一根刀轴上,并通过双侧齿轮传递扭矩提高抗扭刚度,拓宽了设备剪切厚度的范围,降低了设备加工制造成本。     

基于地应力和二次损伤的预留光爆层爆破参数研究

对于地下开采,预留光爆层进行二次爆破可以保证巷道掘进面轮廓成形效果,减少围岩损伤。基于地应力、应力波和爆生气体等共同作用理论,对预留光爆层二次爆破进行参数优化。分析预留光爆层厚度对地应力重分布的影响以及二次应力对爆生裂纹扩展的影响,可知二次应力会抑制爆生裂纹扩展,且预留光爆层厚度与二次应力大小呈正相关;分析在不考虑损伤、考虑一次损伤和考虑二次损伤条件下,轴向不耦合系数及炮孔间距大小的变化,可知考虑损伤可以适当增大轴向不耦合系数和炮孔间距。以焦家金矿深部开采工程为背景,对比爆破参数优化前后爆破效果,可知在深部开采时考虑地应力和损伤,能提高半孔率和节约成本。研究结果为地下开采爆破标准化提供了理论依据。     

Model system of binaural hearing. III. Binaural processing of information about short sounds

A model of neuronal structures of the medial superior olivary nuclei and inferior colliculus performing the determination of the direction on the source of the short (shorter than 10 ms) sound signals is presented. In the model the difference between the moments of the arrival of the two informational messages formed on the stage of monaural information processing is calculated. The result of this calculation is the firing probability of the primary detector (the neuron of the medial superior olivary nucleus). Because of the internal noise the curve of this probability as a function of the direction on the source is smoothly sloped. The estimation of the direction is the result of the statistical processing of the responses of the primary detectors ensemble. The direction on the source of sound is coded by a position of the secondary detector (the neuron of the inferior colliculus) on the direction "scale".     

Alternative operative exposures of the posterior aspect of the humeral diaphysis with reference to the radial nerve

An anatomical study was performed to define the course of the radial nerve in the posterior aspect of the arm, with particular reference to its relationship to operative exposures of the posterior aspect of the humeral diaphysis. In ten cadaveric specimens, the radial nerve was found to cross the posterior aspect of the humerus from an average of 20.7 +/- 1.2 centimeters proximal to the medial epicondyle to 14.2 +/- 0.6 centimeters proximal to the lateral epicondyle. As it crossed the posterior aspect of the humerus in each specimen, the nerve had several branches to the lateral head of the triceps; however, no branches were found innervating the medial head of the triceps in the posterior aspect of any of the specimens. At the lateral aspect of the humerus, the nerve trifurcated into a branch to the medial head of the triceps, the lower lateral brachial cutaneous nerve, and the continuation of the radial nerve into the distal part of the upper arm and the forearm. Three operative approaches were performed in each specimen. The posterior triceps-splitting approach exposed an average of 15.4 +/- 0.8 centimeters of the humerus from the lateral epicondyle to the point at which the radial nerve crossed the posterior aspect of the humerus. For the second approach, the radial nerve was mobilized proximally to allow an additional six centimeters of the humeral diaphysis to be visualized. The third approach (the modified posterior approach) involved the identification of the radial nerve distally as it crossed the lateral aspect of the humerus, followed by reflection of both the lateral and the medial heads of the triceps medially. This exposure permitted visualization of 26.2 +/- 0.4 centimeters of the humeral diaphysis from the lateral epicondyle proximally. The results after use of the modified posterior approach in seven patients were also reviewed.     

Comparison of the power and accuracy of biallelic and microsatellite markers in population-based gene-mapping methods

Because of their great abundance and amenability to fully automated genotyping, single-nucleotide polymorphisms (SNPs) and simple insertion/deletion are emerging as a new generation of markers for positional cloning. Although the efficiency and cost associated with the markers are important in the mapping of human disease genes, the power to detect the linkage between the marker and the disease locus, as well as the accuracy of the estimation of the map location of the disease gene, dictate the selection of the markers. Both the power and the accuracy depend not only on the type of the markers but also on other factors, such as the age of the disease mutation, the magnitude of the genetic effect, the marker-allele distribution in the population, mutation rates of marker loci, the frequency of the disease allele, the recombination fraction, and the methods for mapping the human disease genes. In this article, we develop a mathematical framework and the analytical formulas for calculation of the power and the accuracy and investigate the impact that the aforementioned factors have on the power and the accuracy, by using two population-based gene-mapping methods-likelihood-based linkage-disequilibrium mapping and the transmission/disequilibrium test, for both biallelic SNPs and microsatellites. These studies provide not only guidance in selection of the markers and in the design of the sample scheme for positional cloning but also insight into the biological bases of the mapping of human disease genes.     

半透水边界砂井真空联合堆载预压Hansbo固结解

把砂井地基上下边界视为半透水边界,以研究顶部垫层和底部下卧层透水特性对砂井地基固结过程的影响.根据轴对称固结方程和等应变假定,利用Hansbo法获得了真空联合堆载预压下半透水边界砂井地基的固结解答,分析了上下边界透水系数对真空和堆载预压固结度和沉降的影响,比较了真空单独预压下本文解与Indraratna等解答和周琦等解答的联系和差别.研究表明,(1)不管真空预压还是堆载预压,固结时间因子相同时地基固结度随边界透水系数增大而增大.(2)对于真空预压,下边界透水系数越大,地基的最终沉降越小,固结期间时间因子相同时的沉降也越小;上边界透水系数越大,固结期间时间因子相同时的沉降越大.(3)对于堆载预压,不管上边界还是下边界,边界透水系数越大,最终沉降不变,而固结期间时间因子相同时的沉降越大.(4)当真空预压上边界透水时,周琦等解答的固结度大于本文解答的固结度大于Indraratna等解答的固结度.为了提高真空预压的最终沉降,需减少地基下边界的透水性.      

外加直流电场无污染脱氧模拟研究

为了更好地提高脱氧效率,建立了渣-钢外加电场脱氧系统模拟模型。模拟分析了电场参数、电极参数、熔渣及钢液属性等对渣-钢系统中电流密度分布的影响,并对模拟结果进行试验验证。结果表明,随着系统施加电压、阳极电极直径的增加和阳极到渣-钢界面距离的缩短,系统中的最大电流密度增大;渣电阻率的降低有助于提高阳极附近的电流密度,而渣的相对介电常数的增大有利于系统中最大电流密度的提高;脱氧速率最高可以达到0.002 18%/min。