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1.
磁悬浮力成金特征及成矿机制——以吉林夹皮沟金矿为例   总被引:3,自引:3,他引:3  
孙忠实  邓军 《地质科学》2002,37(2):233-242
磁斥力(又称磁悬浮力)在地学中的应用正在受到越来越多的关注本文以吉林夹皮沟金矿为例,通过磁悬浮成矿背景,磁悬浮力与成矿物源的关系,磁悬浮力持续存在与钾质岩石放射性核热能在富金中的作用,磁悬浮力与流体运移模式,磁悬浮力大小交变规律与成矿流体脉动等距性贯入耦合关系等特征的讨论,提出磁悬浮力成矿机制.该机制的主要学术思想是通过板块体旋转所产生的岩石剩磁磁斥力、磁斥力对流体的影响或控制来探求成矿作用.它力图从另一角度对绿岩金矿、与金相伴的有色多金属抗磁性矿物、金铀矿床和喷溢铁矿浆等方面给出若干新的解释,为成矿作用研究开辟新的领域.  相似文献   

2.
A new formulation for the phase matrix for the scattering of radiation in a weak magnetic field is presented. The phase matrix is represented as a product of individual matrices that depend on the angle of incidence and the scattering angle. It is shown that the Hanle effect is absent in observations of scattered light in the solar atmosphere when the magnetic field is perpendicular to the atmosphere. In strong magnetic fields, the phase matrix depends only on the direction of the magnetic field relative to the basic coordinate system.  相似文献   

3.
板块构造与全球大型-超大型金矿分布间的内在联系一直被世人所关注.本文根据板块体转动引起岩石剩磁矢量方向的变化(由原正-负磁极相对变为正-正极或负-负极相对)所产生的磁斥力以及磁斥力对金元素运移和富集的控制作用,探求磁斥力的形成特征与全球金矿分布规律的对应关系.基于磁力控矿理论基础、磁斥力形成和控矿机制及全球大型-超大型金矿分布规律的讨论,提出全球大型-超大型金矿床的形成,除有区域构造应力和重力等作用外,还应与磁斥力作用有关.磁斥力值、板块体旋转角度及金矿床的形成3者间具有一定的对应性,磁斥力大小与金矿床形成规模成正比.这种正比关系决定了全球大型-超大型金矿床空间展布主要呈环形、对顶角式和等距性分布,反映出全球成矿演化的总趋势.  相似文献   

4.
毕金锋  罗先启  沈辉 《岩土力学》2014,35(Z1):257-263
地质力学磁力模型试验利用电磁力(场)模拟重力(场)的原理研究地质力学工程问题,采用的相似材料由铁磁材料与岩土体混合而成。铁磁材料在磁场中的受力方向和大小与所处空间的磁通密度梯度的大小和方向有关,为了模拟均匀的重力场,需要得到在一定空间范围内磁通密度梯度大小相同、方向单一的磁场。根据电磁学基本原理,构建了3种磁路形式以获得磁通密度梯度相对均匀的磁场,对磁力模型试验相似材料进行加载。对比3种磁路,在最佳试验区内开放式磁路对磁场的利用率更高,所以在电流相同条件下等到的磁通密度梯度的量值也更大。与另两种磁路形式相比,尽管半开放式磁路在重量和工作效率上的性能不及开放式和封闭式磁路,但其最佳试验空间的磁通密度梯度的均匀性最好,误差在5%以内,半开放式磁路可以作为地质力学磁力模型试验的磁场发生装置。  相似文献   

5.
建立合理水下小目标磁探测线间距需以定量分析各种因素对其影响为基础。将水下小目标的磁场模型视为磁偶极子,建立水下小目标的磁场空间衰减规律。根据水下目标磁探测的原理及其工作背景,对目标磁距大小、仪器信噪比、地磁变化、日变影响、测船的定位误差等因素进行综合分析,得出磁力仪在探测某一已知物时的测线间距计算公式。  相似文献   

6.
Rare earth sintered magnets (Nd magnet) have been used in many applications such as computer and industrial equipment, automobile manufacturing and many others. They are highly efficient and reduce energy consumption because of their superior magnetic properties. The element dysprosium (Dy) contained in the Nd magnet is important and indispensable. It improves the stability of the Nd magnet by enhancing the coercive force of its magnetic properties at high temperature. Dy is not so abundant. The rapid growth of the Nd magnet may result in Dy shortage. Exploration for new deposits of Dy is desired.  相似文献   

7.
本文以吉林夹皮沟金矿带为例,通过板块碰撞或旋转所产生的磁斥力和电场来探讨流体中成矿元素运移和富集机制。基于块体转动与岩石剩磁磁斥力的产生,岩石电、磁场的形成和阴 阳离子相向漂移的地质证据及成矿流体与磁感应矢量、电导率间对应关系的讨论,表明:1)成矿元素的富集发生于新旧电、磁场交替变化过程中;2)岩石电场正、负极控制阴、阳离子作相向漂移运动,是流体中成矿元素运移、富集的主要控制因素之一;3)深大断裂界面间的磁斥力是Au、Ag、Cu、Pb和Zn等有色多金属抗磁性元素成矿的有利场所。  相似文献   

8.
Exact analytical expressions for the scattering phase matrix are presented for various models of a turbulent magnetic field having a symmetry axis in the solar atmosphere. The polarization of the scattered radiation in the plane of the scattering is shown to be virtually independent of the predominant direction of the turbulent magnetic field. The Hanle effect does not operate in a longitudinal magnetic field normal to the surface of the atmosphere, since the phase matrix has the form of a resonance phase matrix with zero magnetic field.  相似文献   

9.
罗先启  毕金锋 《岩土力学》2018,39(1):367-374
地质力学磁力模型试验借鉴土工离心模型试验中利用离心力模拟重力的思想。在均匀梯度磁场中,掺有铁磁材料的相似材料会受到均匀的磁力作用,由此可以利用均匀的磁力场模拟重力场。根据电磁学基本原理和磁路设计原理,设计并制造了一台2 000匝线圈的均匀梯度磁场发生装置。该装置在220 V电压情况下,能够产生0~16 A电流,在1.2 m×1.2 m×1.0 m试验空间内,可将磁性相似材料的重度提高10~30倍。以锦屏一级电站左岸高陡边坡为例,进行地质力学磁力模型试验。试验结果表明,在一定的电流作用下,可以使模型所受体力的提高倍数达到相似比的要求,并与数值模拟结果进行了对比,试验结果与计算结果基本一致。在增加通电电流时,试验设备可以模拟边坡的超载过程,进而可以求出边坡的超载安全系数。  相似文献   

10.
为了减小时间域航空电磁法在强磁性地区应用时产生的磁极化电流对反演的影响,提出了一种在雅可比矩阵中加入磁导率偏导数,将电阻率、磁导率和层厚进行全时同步反演的方法。将磁性均匀半空间模型、单个磁性模型和多个磁性层模型的时间域响应添加高斯噪声作为模拟数据进行全时反演,得到的模型与理论模型拟合较好,拟合误差均在3%以下,验证了本文算法的有效性,说明在强磁性地区本文提出的算法能有效解决地下介质的电性分布。  相似文献   

11.
The magnetic properties and abrasion resistance of selected low-carbon steels were investigated with respect to their suitability as induction matrix materials. Low-remanent ferromagnetic steels and a paramagnetic steel were used in magnetic separation tests with siderite and hematite ores. It was found that recovery and grade for all ferromagnetic materials were equivalent, while recovery for paramagnetic steel was lower, and increased with increasing magnetic induction. However, all investigated steels are less susceptible to hold highly coercive tramp iron which usually causes matrix clogging. Likewise, all selected stainless steels are more abrasion resistant than currently employed matrix materials.  相似文献   

12.
磁铁矿床磁异常的模糊综合评价模型   总被引:1,自引:0,他引:1  
以往的物探异常评价通常都是定性的,本文针对一矽卡岩磁铁矿区,提出磁异常的一种定量综合评价模型——隶属函数法模糊综合评价模型;并以一种新的参量;矿优度系数矩阵,B—综合评价录属度矩陈B的转置)作为磁异常的最终评价标准。检验表明,评价模型的准确率达84%。  相似文献   

13.
The theory required to calculate the phase matrix for resonance scattering in the presence of a magnetic field is set out. Interference effects between radiation from individual magnetic sublevels of the atom are taken into account. Errors in the algorithms used to calculate the phase matrix published earlier by other authors are identified.  相似文献   

14.
基于初参数法的多心圆拱隧道衬砌结构内力与变位求解   总被引:1,自引:0,他引:1  
孙富学  蔡晓鸿  朱云辉 《岩土力学》2009,30(4):1127-1130
基于初参数解析方法的原理,建立了混凝土衬砌弹性地基圆弧曲梁内力和变位求解的初参数矩阵方程。对于多心圆拱隧道衬砌结构,利用曲梁初参数矩阵方程,以及结构的对称性和圆拱弧段交接点处内力平衡和变位协调条件,求解出了矩阵方程中初参数值,可进一步应用初参数矩阵方程求解圆拱弧段各点的内力与变位值。实例计算表明,其解析思想是可行有效的,可为类似衬砌结构设计提供一条可靠的内力分析途径。  相似文献   

15.
利用重磁水平和垂直二阶导数确定东北地区梯度带   总被引:1,自引:0,他引:1  
分析了东北地区的重、磁场特征,同时对研究区的布格重力异常和航磁异常数据进行水平和垂直求导。水平和垂直参量图能给出断裂和走向的信息。结合布格重力异常图可以得出东北地区重力梯度带的走向和边界,并对比重力和磁力的垂直和各个角度的水平二阶导数来综合确定东北地区梯度带。利用求重力和磁力的水平和垂直二阶导数来划分东北地区梯度带。  相似文献   

16.
Tl and Pb isotopic abundances have been measured in various phases from Allende and the distribution and siting of these elements in the matrix phase investigated. Matrix fractions, prepared by sieving, sedimentation, magnetic separation and acid etching, were further characterised by X-ray diffraction and SEM. Tl concentrations range from 1 ppb in coarse grained inclusions to 1560 ppb in the acid-etched carbon residues and from 32 ppb to 194 ppb in the 16 matrix fractions. Pb concentrations which range from 0.1 ppm to 3.1 ppm, are enhanced in magnetic phases and depleted in Allende pentlandite relative to the whole meteorite. The Tl-204Pb abundance diagram is described near the origin by the inclusions and chondrules and extends through sulphide to the non-magnetic and magnetic matrix fractions. Abundances in the finest grained matrix fractions form a linear trend which passes through the origin and the Orgueil and Murchison whole meteorite data. The deviation of magnetic matrix fractions from the above linear trend is probably related to the presence of an intimate association of an awaruite-sulphide-carbon species. 92% of the Tl in the carbon residues, which is released on hydrolysis with HCl, probably resides in an organic host molecule(s) on the macromolecular carbonaceous material, whereas the surface film of organics on the matrix grains shows no apparent enrichment of Tl.Tl and 204Pb abundances revealed an inverse correlation with grain size and a distribution within the grains rather than as a surface layer, is indicated. Constraints placed by the data on the formational environment of the matrix grains are considered. Interstellar shock heating and rapid radiative cooling is a possible mechanism for the establishment of the observed inverse correlation of volatile abundance with grain size. Matrix data do not lend support for a recent redistribution of lead as an explanation for the apparent excess Pb in Allende. The apparent initial Pb isotopic compositions of the matrix fractions are heterogeneous and not attributable to terrestrial contamination. The very magnetic fractions have high abundances of Pb and the least radiogenic apparent initial Pb compositions, whereas the non-magnetic fractions have lower Pb abundances but more radiogenic apparent initial Pb compositions. The data also indicate that use of the predicted Tl-204Pb cosmothermometer, to infer accretion temperatures, is apparently not valid for individual phases of Allende.  相似文献   

17.
It is shown that the magnetic force on a highly-magnetic particle in a slurry is a strong function of the particle shape and the concentration density of the magnetic particles in the suspension. An expression is derived for the coagulation forces between magnetized particles as a function of magnetic moment, size, and concentration.  相似文献   

18.
A new derivation of the matrix equations of radiative transfer in a magnetic field is presented, which is based on the classical approach of M. Born and V.E. Stepanov. Convenient vector relations making it possible to formulate the radiative-transfer equations in an arbitrary coordinate system and choose a convenient system of Stokes parameters are presented. The cases of the solar atmosphere and a stellar atmosphere with a dipolar magnetic field are presented as examples. The use of the radiative-transfer equations written in terms of two main oscillation components (the method of V.E. Stepanov) can lead to crude errors when the complex nature of the absorption coefficients is taken into account.  相似文献   

19.
To improve the enrichment of the Thanetian marine phosphate ore deposit from the quarry of Bled El Hadba (Djebel Onk, Algeria) before its exploitation, we first conducted a joint study using different techniques for comparison. These studies reveal that magnetic minerals play a significant role within the matrix of the central productive unit which is squeezed between two other units. Magnetic separation procedures show that there are some positive correlations between magnetic susceptibility and grain size fraction (80–250 μm). These dolomite-rich fractions are more clearly separated. Different tools were used to characterize the magnetic minerals (X-ray, microprobe, differential scanning calorimetry, thermogravimetric and thermomagnetic analyses). They show correlations between magnetic phases and the presence of associated magnetic minerals within the matrix or included in the phosphate ore deposit. They enabled us to distinguish a series of magnetic minerals (magnetite, hematite, maghemite, goethite, ilmenite, pyrite, iron–titanium oxide and titanium oxide sulphate) and to determine that Fe and Ti are prevalent in the separated fractions, following the same variation as Mg. The phosphorous (phosphate) rate is higher in the non-magnetic material, especially in the layers that are rich in dolomitic carbonates (upper and lower units), which could be trapped within the dolomitic matrix, while Magnesium (dolomite) is more important in the magnetic fraction. The separation of phosphate elements and dolomite carbonates is effective and therefore the ore can be enriched through magnetic procedures. Comparison between products enriched by magnetic separation, flotation and calcination showed important differences, chemically, economically and technically speaking.  相似文献   

20.
对第四纪典型风成马兰黄土、受成壤作用影响较大的第五层古土壤、新近纪红粘土、埋藏化石的红粘土围岩层的磁组构分析表明:新近纪红粘土的磁组构参数P、F值界于马兰黄土—第五层古土壤与经流水改造的化石围岩之间,L均值与风成黄土相当, Q均值接近于水成红粘土化石围岩,而在事件性沉积方面又类似于风成马兰黄土、第五层古土壤;磁组构参数F-L、P-Q组合图位于马兰黄土—第五层古土壤与经流水改造的化石围岩过渡带。反映红粘土沉积物既具有风成原地堆积物的磁组构参数特征,又有经历了后期流水改造的化石围岩的特点,是风成原地堆积与风动力搬运而来的母质颗粒经后期流水改造共同作用的产物。  相似文献   

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