高精度磁测在白尕湖铁矿勘探中的应用

本文在对白尕湖地区的地质资料和物探资料进行整理分析的基础上,布置了磁法物探工作,对获得的数据进行了数据的网格化、滤波、化极、解析延拓等处理,形成了各种磁法成果图件,通过对地磁场特征分析及地质解释,推断测区有铁矿床存在。     

磁法勘探在浅覆盖区地质填图中的应用

区域物探资料特别是磁法资料由于磁异常的迭加,既包括了浅部的岩性分布信息,也包含了地下的深部构造信息,采用向上延拓、垂向一阶导数等多种异常分离技术对地磁异常进行分解,提取浅部场来分析近地表地质体的分布;     

陈台沟叠加磁异常解译

对地表及旁侧有干扰的叠加磁异常,经过计算、消除干扰异常后,通过延拓、正反演推测矿体形态。     

波前编码景深延拓照相系统的仿真研究

本文利用Zemax光学设计软件设计一个景深延拓照相系统,并分别对传统光学系统和波前编码景深延拓照相系统在不同离焦情况下进行了成像模拟。证明了波前编码景深延拓照相系统在滤波前在不同的离焦下所成的图像具有相似的模糊,在滤波后系统能够在较大范围内成清晰像。     

高精度磁法数据处理在地质找矿中的应用

磁法勘探是通过观测和分析岩矿石或其它探测对象磁性差异所引起的磁异常,来研究地质构造、矿产资源或其它探测对象的一种地球物理方法。在地球物理勘探方法中,磁法勘探是发展最早,应用广泛的一种物理勘察方法。随着时间的发展,磁法数据处理已经发展到比较成熟的地步,数据处理的方法主要有化极、向上延拓、向下延拓、一阶求导等,通过这些方法处理后在对磁异常进行推断解释,成果更加具有说服力。因此,磁法数据处理处理方法在寻找构造和地质找矿中发挥着比较重要的作用。     

采用高斯迭代滤波的等值面折射体绘制

体绘制增加折射光学效果,能够明显地增强三维空间层次关系,但折射体绘制对原始数据的噪声非常敏感。在本文中我们提出了一种基于高斯迭代滤波的折射体绘制方法。首先在数据预处理阶段对CT数据进行高斯迭代滤波,然后采用阈值法把CT数据分割为不同区域,通过折射率传递函数映射为不同的折射率,最后根据Shell定理对体数据进行折射体绘制。结果显示绘制质量得到了显著提高。     

确定磁性体性质的解释推断方法

确定磁性体性质的解释推断方法,可提高找矿工作的效率。对测区内磁异常解释前,应认真研究分析区内磁异常的平面和剖面特征,在进行适当分类编号后,再对各类磁异常逐一解释推断。判断引起磁异常磁性体的性质,首先要研究磁异常是由地表出露的地质体所引起,还是由隐伏磁性体所引起;其次要认真研究隐伏磁性体的性质,判断其直接和间接找矿意义,达到提高找矿精度的目的。     

低层大气急流的季节观测分析

本论文分析了低层大气急流的季节变化.原始数据是美国的编号为03937的站点2002-2004年的数据,笔者对数据中经向风和纬向风这两个参数进行处理.通过对其拟合处理,运用IDL软件编程输出图形,发现低层大气急流的季节变化规律,即经向风的风速随着高度的变化幅度小,纬向风的风速随着高度的升高变化幅度比较大,春冬季急流最大,而夏季急流最小.     

磁法勘探在金属矿的应用

随着地面磁测工作的发展,在地质矿产勘查领域,经常应用质子磁力仪进行地面磁测工作,往往取得良好的地质效果。通过测出不同磁法强度的各种岩矿石在地磁场中所引起的磁异常,分析异常特征和异常的分布规律,以及地质构造或地质体之间的联系,进行地质找矿或评价矿产分布。     

青海省都兰达日沟脑铁矿磁异常特征分析

都兰达日沟脑矿区勘察程度低,为了查明区内成矿地质特征、地球物理特征、磁异常分布特征,对研究区内成矿地质条件及磁异常特征进行了分析研究,采用地面高精度磁测方法判断引起磁异常的地质体特征及判断磁性体及矿体的大小、产状、埋深得出:1矿区内岩浆活动与断裂发育,具有优越的内生金属矿产成矿地质条件,矿区内磁铁矿体都属岩浆型,铁矿多产于中基性岩体接触带东西向断裂构造带内;2矿区内岩石与磁铁矿磁性差异大,具备用磁测手段寻找磁铁矿地球物理前提。     

The relative permeability of iron,nickel and permalloy in high frequency electromagnetic fields

The relative magnetic permeability of iron, nickel and permalloy was measured over the range of wave-lengths from 70 to 200 meters by the heterodyne balance method and by the resonance method. Nothing suggestive of the anomalous dispersion of the magnetic permeability reported in this region by Wwedensky and Theodortschik was found when certain precautions were observed in carrying out the measurements. When these precautions were neglected irregular breaks resulted in the curves of permeability as a function of wavelength which varied in position with the conditions of the circuit.The high frequency resistance of iron, nickel and permalloy wires was measured over the range of approximately fifty thousand kilocycles from two to three meter wave-lengths. What appeared to be anomalous variations at certain frequencies were found not to exist when the proper precautions were observed in making the measurements.     

Magnetic field of rotating bodies

A laboratory experiment devoted to the measurement of the magnetic field created by a rotating body is described. Using an original method of detection, the effects of the magnetic field of a rotating body were detected and their properties investigated. Based on a model proposed by the author, an interpretation of the experimental results is given.     

Prevention of isoproterenol-induced cardiac hypertrophy by eugenol, an antioxidant

Recent reports on the involvement of calcineurin in cardiac hypertrophy and its susceptibility to free radicals, prompted us to examine possible beneficial effects of dietary antioxidants in this regard. In continuation of initialin vitro studies revealing eugenol to be a potent calcineurin inhibitor, we investigated its ability to reverse isoproterenol-induced cardiac hypertrophy in rats. Intraperitoneal administration of isoproterenol (1 mg/kg body wt/day for 10 days) induced cardiac hypertrophy with increased heart weight and enhanced apoptosis of myocytes concomitant with accumulation of reactive oxygen species, decreased glutathione contents, increased activities of calcineurin and protein kinase C in ventricular tissue. Administering eugenol for 3 days (1 mg/kg body wt/twice a day), followed by combined administration of isoproterenol and eugenol resulted in significant reversal of cardiac hypertrophy and restoration of above changes. These results suggest that eugenol, a natural antioxidant of dietary origin, may offer potential benefits in the management of cardiac hypertrophy.     

Quantum anomalous Hall effect

Hall efect is a well-known electromagnetic phenomenon that has been widely applied in the semiconductor industry.he quantum Hall efect discovered in two-dimensional electronic systems under a strong magnetic ield provided new insights into condensed mater physics,especially the topological aspect of electronic states.he quantum anomalous Hall efect is a special kind of the quantum Hall efect that occurs without a magnetic ield.It has long been sought ater because its realization will signiicantly facilitate the studies and applications of the quantum Hall physics.In this paper,we review how the idea of the quantum anomalous Hall efect was developed and how the efect was inally experimentally realized in thin ilms of a magnetically doped topological insulator.     

Raise quantum anomalous Hall states up

Experimental progress on the quantum anomalous Hall(QAH)effect has been significantly accelerated recently by the discovery of an intrinsic magnetic topo-logica...     

The p-orbital magnetic topological states on a square lattice

Honeycomb or triangular lattices were extensively studied and thought to be proper platforms for realizing the quantum anomalous Hall effect (QAHE), where magnetism is usually caused by d orbitals of transition metals. Here we propose that a square lattice can host three magnetic topological states, including the fully spin-polarized nodal loop semimetal, QAHE and the topologically trivial ferromagnetic semiconductor, in terms of the symmetry and k · p model analyses that are material independent. A phase diagram is presented. We further show that the above three magnetic topological states can indeed be implemented in the two-dimensional (2D) materials ScLiCl₅, LiScZ₅ (Z=Cl, Br) and ScLiBr₅, respectively. The ferromagnetism in these 2D materials is microscopically revealed from p electrons of halogen atoms. This present study opens a door to explore the exotic topological states as well as quantum magnetism from p-orbital electrons by means of the material-independent approach.     

Unconventional Hall effect induced by Berry curvature

Berry phase and Berry curvature play a key role in the development of topology in physics and do contribute to the transport properties in solid state systems. In this paper, we report the finding of novel nonzero Hall effect in topological material ZrTe₅ flakes when the in-plane magnetic field is parallel and perpendicular to the current. Surprisingly, both symmetric and antisymmetric components with respect to magnetic field are detected in the in-plane Hall resistivity. Further theoretical analysis suggests that the magnetotransport properties originate from the anomalous velocity induced by Berry curvature in a tilted Weyl semimetal. Our work not only enriches the Hall family but also provides new insights into the Berry phase effect in topological materials.     

An efficient solution of hamiltonian boundary value problems by combined gauss pseudospectral method with differential continuation approach

Our paper deals with an effective application of the pseudospectral method to solution of Hamiltonian boundary value problems in optimal control theory. The developed numerical methodology is based on the celebrated Gauss pseudospectral approach. The last one makes it possible to reduce the conventional Hamiltonian boundary value problem to an auxiliary algebraic system. The implementable algorithm we propose is computationally consistent and moreover, involves numerically tractable results for a relative small discretization grids. However, the solution of the obtained algebraic equations system may has a low convergence radius. We next use the differential continuation approach in order to weaken the necessity of the well-defined initial conditions for the above algebraic system. The presented solution procedure can be extremely useful when the generic shooting-type methods fail because of sensitivity or stiffness. We discuss some numerical results and establish the efficiency of the proposed methodology.     

Science and statistical victim: modernizing knowledge in breast implant litigation

The advent of mass torts in US federal courts in the latter third of the 20th century accelerated a process of modernization in an institution that was unprepared for standardized approaches to dispute resolution. Faced with large-scale technological disasters, in particular, courts struggled to reform both their procedures and their fact-finding approaches in order to deal with multiple claimants in consolidated proceedings. Using silicone gel breast implant litigation as a case study, this paper argues that the attempt to marry judicial concerns for individual justice with administrative concerns for speed, efficiency and economy has produced anomalous results. The testimony of the clinician and the victim has become less relevant as judicial remedies take account of injuries done to classes of plaintiffs. Subjective claims about the body are subordinated to statistical correlations between exposure and grouped complaints. At the same time, the transfer of fact-finding authority from juries to judges under new evidentiary rules has privileged the judiciary's lay knowledge and experience over that of the jury. While these transformations may hasten the processing of cases, the paper questions whether the courts can legitimately take on board the issues of risk and social justice in contemporary industrial societies.     

An improved lock detector for phase-locked communication receivers

A quadrature lock detector is incorporated in almost all coherent radio communication receivers. This commonly-used receiver subsystem is comprised of a quadrature phase detector that drives a low-pass filter, the output of which is subjected to a user-specified threshold to make a lock/unlock decision. Signal acquisition and phase lock are declared if an above threshold condition is observed. Unfortunately, this method of lock detection may yield a positive lock indication when the receiver is false locked; i.e., a classical quadrature lock detector may generate a false-positive lock indication. This tendency to produce an incorrect lock indication can be reduced significantly by using the new lock detector algorithm that is described here. Compared to the classical quadrature lock detector, the new lock detector is better able to differentiate between true phase lock and anomalous false lock. The classical quadrature lock detector is a simple, first-order approximation of the new lock detector algorithm. That is, the new lock detector algorithm consists of a classical quadrature detector that is augmented by a correction term.