磁法技术在金属矿山勘探中的前瞻性发展趋势分析

金属矿山的勘探一直是地质勘探的重要组成部分。传统的金属矿山勘探方法存在许多不足,如勘探深度有限,精确度不高,破坏性大等。为了解决这些问题,磁法技术被广泛应用于金属矿山的勘探中。本文以磁法技术在金属矿山勘探中的应用为核心,分析了磁法技术的前瞻性发展趋势。通过对相关理论研究和实际案例分析发现,磁法技术在金属矿山勘探中有着其独特的优势,例如大地深度勘探、定位精度高、损害小等。同时,随着磁法技术的发展,其在勘探中的应用也呈现出前瞻性的发展趋势,如高分辨率、深层勘探、信息融合与解释等。这一趋势将会进一步提高金属矿山的勘查效果和效率,为找矿、评价矿床和开发矿产等提供更为准确和可靠的科学依据。

利用磁法技术推断傲牛铁矿深部成矿的可能性

利用磁法综合处理技术能够有效的推断出测区深部成矿的可能性,用向上延拓、差值切割法、匹配波法、3D欧拉反褶积计算等方法对傲牛铁矿磁法数据进行数据处理,各种方法处理结果基本一致地反映了深部地质情况。

磁法检测技术在应力检测中的研究

磁法检测技术是通过对试件磁信号的检测,对试件的压力集中情况和疲劳损伤程度进行早期评估的一种新的检测手段。该方法的使用可以正确反映待测试件应力的变化。为了精确测量试件的磁信号强度,在研制了高灵敏度磁矢量探头检测的试验平台的同时,建立了检测信号与磁导率的关系算法。试验发现,应力集中区域,会导致该区域与周边的区域磁导率发生相应的差异,即随着试件中所存在的残余应力增加,所采集得到的磁信号强度也在增大。

浅析磁法勘察技术在煤田自燃边界中的应用

中国的煤炭产量位于世界首位,其中约1/3的产量经过火力发电转变为动力电,所以,煤炭也是我国的主体能源。促进煤炭工业的可持续发展,也是构建资源节约型、环境友好型社会的必然要求,它的安全生产更是直接影响着我国的能源安全,并且也对国民经济的稳定和发展起着战略性的作用。

高精度磁测技术在栾川县松树沟铁矿区中的应用分析

随着我国国民经济迅速发展,国内钢铁市场不断变化,对高强度钢、特种钢需求日益增强。高精度磁测技术作为寻找磁铁矿最为直接有效的手段得到充分应用和发展。本文结合实际生产,总结出高精度磁测技术在本矿区内使用的成功经验,供以后类似项目参考。

油井套管应力检测仪器研制与应用

利用逆磁致伸缩效应的铁磁材料应力无损检测技术在无损检测领域中已经发展成熟。在此基础上,开发了一种可以在套管发生塑性形变之初就可能给出套管损坏预报的油井套管应力检测仪。它在大庆油田5口套损井的检测试验表明:该仪器对套管微变形反映明显,此方法在套管检测方面具有其优势。

Finite element solution based on fast numerical technique for large-scale electromagnetic computation

A numerical technique of the target-region locating （TRL） solver in conjunction with the wave-front method is presented for the application of the finite element method （FEM） for 3-D electromagnetic computation. First, the principle of TRL technique is described. Then, the availability of TRL solver for nonlinear application is particularly discussed demonstrating that this solver can be easily used while still remaining great efficiency. The implementation on how to apply this technique in FEM based on magnetic vector potential （MVP） is also introduced. Finally, a numerical example of 3-D magnetostatic modeling using the TRL solver and FEMLAB is given. It shows that a huge computer resource can be saved by employing the new solver.

The parallel 3D magnetotelluric forward modeling algorithm

The workload of the 3D magnetotelluric forward modeling algorithm is so large that the traditional serial algorithm costs an extremely large compute time. However, the 3D forward modeling algorithm can process the data in the frequency domain, which is very suitable for parallel computation. With the advantage of MPI and based on an analysis of the flow of the 3D magnetotelluric serial forward algorithm, we suggest the idea of parallel computation and apply it. Three theoretical models are tested and the execution efficiency is compared in different situations. The results indicate that the parallel 3D forward modeling computation is correct and the efficiency is greatly improved. This method is suitable for large size geophysical computations.

Gallbladder lymphangioma:A case report and review of the literature

Lymphangiomas are rare, benign tumors of the lymphatic system, usually present in children aged 5 years and younger. Because they are asymptomatic until the mass enlarges to cause symptoms, most lymphangiomas are diagnosed at adulthood incidentally. We experienced a case of a 60-year-old man diagnosed with a cystic lymphangioma of the gallbladder, which was successfully resected without any complication. Magnetic resonance imaging and magnetic resonance cholangiopancreatography were very helpful for the diagnosis of the cystic lesion around the gallbladder as were ultrasonography and computed tomography scan. These showed a multi-lobulated cystic mass with intact cystic duct and bile duct in the gallbladder fossa. The patient underwent an open cholecystectomy and the histological findings were consistent with a cystic lymphangioma of the gallbladder. We here report the case of cystic lymphangioma of the gallbladder with a review of the literature.

Detection technology and application of electromagnetic method for hidden danger of water gushing at coal face

The principles, methods, technologies and application effects of several electromagnetic methods for the detection of the hidden danger of water gushing at the coal face were introduced. Also, emphasis was laid on expounding the methods, principles and effects of down-hole detections by electric transmission tomography and transient electromagnetic method. The potential of point power supplied in the underground homogeneous semi-space, as well as the response to a low-resistivity abnormal body in the homogeneous semi-space, was simulated by adopting 3-D finite element method to interpret the basic theory of the electric transmission tomography. The results of actual measurement show that the mine electromagnetic method is sensitive to water-bearing low-resistivity bodies and can play a unique role in detecting the hidden danger of water gushing at the coal face.

Research on application of transient electromagnetic technology in coal mine

Studied the principle of transient electromagnetic method in coalmine and solved the computation of the whole time apparent resistivity and the relation between apparent resistivity and exploration depth and so on. Studied the work method of transient electromagnetic method in coalmine and obtained reasonable arrangement way. Studied data processing and explanation method of transient electromagnetic method and obtained high quality electric section. Finally the purpose to detect water-bearing body and water-bearing structure in front of roadway in advance, and detect the water-bearing property of the roof and floor rock layer of coal face were realized by use of transient electromagnetic method.

Three-dimensional tomography using high-power induced polarization with the similar central gradient array

Induced polarization （IP） 3D tomography with the similar central gradient array combines IP sounding and IP profiling to retrieve 3D resistivity and polarization data rapidly. The method is characterized by high spatial resolution and large probing depth. We discuss data acquisition and 3D IP imaging procedures using the central gradient array with variable electrode distances. A 3D geoelectric model was constructed and then numerically modeled. The data modeling results suggest that this method can capture the features of real geoelectric models. The method was applied to a polymetallic mine in Gansu Province. The results suggest that IP 3D tomography captures the distribution of resistivity and polarization of subsurface media, delineating the extension of abrupt interfaces, and identifies mineralization.

Three-dimensional forward modeling for magnetotelluric sounding by finite element method

A finite element algorithm combined with divergence condition was presented for computing three-dimensional(3D) magnetotelluric forward modeling. The finite element equation of three-dimensional magnetotelluric forward modeling was derived from Maxwell's equations using general variation principle. The divergence condition was added forcedly to the electric field boundary value problem, which made the solution correct. The system of equation of the finite element algorithm was a large sparse, banded, symmetric, ill-conditioned, non-Hermitian complex matrix equation, which can be solved using the Bi-CGSTAB method. In order to prove correctness of the three-dimensional magnetotelluric forward algorithm, the computed results and analytic results of one-dimensional geo-electrical model were compared. In addition, the three-dimensional magnetotelluric forward algorithm is given a further evaluation by computing COMMEMI model. The forward modeling results show that the algorithm is very efficient, and it has a lot of advantages, such as the high precision, the canonical process of solving problem, meeting the internal boundary condition automatically and adapting to all kinds of distribution of multi-substances.

Biological effect of expression of exogenous human nuclear receptor hLRH-1 in SW480 cells and its molecular mechanism

Objective： To explore the possible biological function of human nuclear receptor hLRH-1 in tumorigenesis and progress of colon cancer. Methods： Plasmids pcDNA3-hLRH-1 were introduced into SW480 cells via lipofectamine. The expression of mRNA and protein of exogenous hLRH-1 were detected by RT-PCR and western blotting, respectively. MTT assay was carried out to survey the proliferation of SW480 cells with overexpression of hLRH-1. Meanwhile, the expression of proliferation-related genes cyclin E1 and cyclin D1, and apoptosis-related genes PTEN and Rbl, were analyzed by realtime RT-PCR. Results： The proliferation of SW480 cells was promoted under the condition of overexpression of hLRH-1. The expression of cyclin E1 was up-regulated significantly, while that of PTEN and Rbl were down-regulated in SW480 cells with overexpressed hLRH-1. Conclusion： The expression of exogenous hLRH-1 in SW480 cells induced the proliferation resulting form up-regulation of cyclin E1, as well as participated in the regulation of apoptosis via influencing the expression of PTEN and Rb1.

Theoretical Studies on the Fe-M Interactions and 31p NMR in Fe（CO）3（EtPhPpy）2MX2 （X=NCS, SCN, CI; M=Zn, Cd, Hg）

To study the Fe-M interactions and their effects on 31p NMR, the structures of Fe（CO）3（EtPhPpy）2 1, Fe（CO）3（EtPhPpy）2M（NCS）2 （2： M=Zn, 3： M=Cd, 4： M=Hg） and Fe（CO）3（EtPhPpy）2CdX2 （5： X=C1, 6： X=SCN） were investigated by density functional theory （DFT） PBE0 method. The stabilities S of complexes follow S（2）〉S（3）〉S（4） and S（3）,.~S（6）〉S（5）, indicating that 6 is stable and may be synthesized. The complexes with thiocyanate are more stable than that with chloride in Fe（CO）3（EtPhPpy）2CdX2. The strength I of Fe-M interactions follows I（2）≈I（3）〈I（4）. The Fe-Cd interactions of 3 and 6, which contain thiocyanate, are stronger than that of 5 with chloride. The charge-transfer, which enhances with the increasing of Fe-M interaction strength, comes from Et, Ph, py, CO groups towards P, Fe, and M atoms. Because the delocalization of thiocyanate disperses the charge of M2＋, the charge-transfer of the complexes with thiocyanate is stronger than that with chloride. There is a a-bond between Fe and Hg atoms in 4. However, in binuclear complexes except 4, the Fe-M interactions act as nFe→nM, σP-Fe→nM and σC-Fe→nM delocalization, and the N-M interactions mainly act as nN→nM delocalization. In binuclear complexes, due to the Fe→M interactions, the strong σFe--C→σ＊Fe--p or σFe-Hg→σ＊Fe--I2 delocalization and the charge-transfer, the electron density on P nucleus is increased, and thus upfield 31p chemical shifts are caused （compared with mononuclear complex 1）.

DETERMINATION OF EQUILIBRIUM MOISTURE OF SOME CHINESE AND AUSTRALIAN COALS BY PULSE PROTON NMR

The varying temperature pulse proton NMR method was adopted to determine the e-quilibrium moisture content of several Chinese and Australian coals. The pulse proton NMR spec-trometry is sensible to the hydrogen at different physical state which occurs for water when temperature changes through 273 K. The equilibrium water,with some interactions to the coal surface, will not transform from one phase to another while the free water does. The measured results are reasonable comparing to the conventional gravimetric method.

Rapid Convergence of a New Wave Iterative Algorithm Used to Model a Patch Structure

The wave iterative method is a numerical method used in the electromagnetic modeling of high frequency electronic circuits. The object of the authors＇ study is to improve the convergence speed of this method by adding a new algorithm based on filtering techniques. This method requires a maximum number of iterations, noted Nmax, to achieve the convergence to the optimal value. This number wilt be reduced in order to reduce the computing time. The remaining iterations until Nmax will be calculated by the new algorithm which ensures a rapid convergence to the optimal result.

Magnetization of microorganism cells by thermal decomposition method

The bio-limited forming technology, a new technology organically integrating microbiology, manufacturing science and materials science, is used in the manufacturing of magnetic or conductive microstructures of different standard shapes. This paper explores the feasibility of magnetizing microorganism with thermal decomposition method. The principle of thermal decomposition of iron pentacarbonyl has been adopted to investigate the cells of Spirulina (a type of nature micro-helical microorganism) coated with pure iron. Further analysis have been conducted on the observations results of hollow micro-helical magnetic particles form, components and the phase structure obtained by using various tools including optical microscopy, scanning electron microscopy (SEM), energy dispersive X-ray detector (EDX), transmission electron microscopy (TEM), and X-ray diffraction analysis (XRD). Results showed that Spirulina cells could be coated with iron particles after the completion of thermal decomposition process, with well-kept shape of natural helixes and consistent components of different sampling points on the surface layer and thickness of layer. After the heat treatment at 700°C, the type of the surface iron layer formed was α-Fe. The paper also investigates the kinetics of the cell magnetization technology by thermal decomposition.

Diluted magnetic oxides

In this review,we review the progress of research on ZnO-and In2O3-based diluted magnetic oxides(DMOs).Firstly,we present the preparation and characterization of DMOs.The former includes the preparation methods and conditions,and the latter includes the characterization techniques for measuring microstructures.Secondly,we introduce the magnetic and transport properties of DMOs,as well as the relationship between them.Thirdly,the origin and mechanism of the ferromagnetism are discussed.Fourthly,we introduce other related work,including computational work and pertinent heterogeneous structures,such as multilayers and magnetic tunnel junctions.Finally,we provide an overview and outlook for DMOs.