Research on the Static Magnetic Field of Ships with Corrosion and Anticorrosion Efficacy Using Electric Dipole Model

In the case of three-layered(air-seawater-seabed)model,the analytical expressions of the static electric and static magnetic field produced by the static electric dipole located in seawater were derived by using the mirror image theory.Combined with the distribution of the underwater electric potential measured in laboratory,an electric dipole model for physical scale of ship was established and the distribution characteristics of an actual ship' s corrosion related magnetic field were obtained.Based on established models,theoretical analysis and calculation were made to catch out the distribution characteristics of static magnetic field related with corrosion and anticorrosion,which can not be measured directly in seawater.The results show that the static magnetic field related with corrosion and anticorrosion is a kind of noteworthy obstacle signal for degaussed ships.

A Magnetic Disturbance Compensation Method Based on Magnetic Dipole Magnetic Field Distributing Theory

The interference of carrier magnetic field to geomagnetic field has been a difficult problem for a long time,which influences on the deviation of navigation compass and the error of geomagnetic measurement. To increase the geomagnetic measuring accuracy required for the geomagnetic matching localization,the strategy to eliminate the effect of connatural and induced magnetic fields of carrier on the geomagnetic measuring accuracy is investigated. The magnetic-dipole's magnetic field distributing theory is used to deduce the magnetic composition in the position of the sensor installed on the carrier. A geomagnetic measurement model is established by using the measuring data with the ideal sensor. Considering the magnetic disturbance of carrier and the error of sensor,a geomagnetic measuring compensation model is built. This model can be used to compensate the errors of carrier magnetic field and magnetic sensor in any case and its parameters have clear or specific physical meaning. The experimented results show that the model has higher geomagnetic measuring accuracy than that of others.

Earth’s Diminishing Magnetic Dipole Moment is Driving Global Carbon Dioxide Levels and Global Warming

Although there are powerful models that couple human activity with elevated atmospheric carbon dioxide levels and global warming, the relationships are still based upon correlations rather than causation. Consequently, there is always the probability of a third factor that produces both. Analyses of the diminishing magnetic dipole moment of the earth and the increased carbon dioxide levels and global temperature within the last 40 years revealed correlations of -0.99 and -0.90, respectively. This powerful association has been reported by other researchers. Why it has been ignored by the scientific community is not clear. The sources of the shift in average geomagnetic (magnetic dipole) intensity have not been identified but these relatively rapid decreases and increases have occurred historically with onsets of periods of warming and cooling, including glacier formation. If the long-time quasi-periodicity of the earth’s magnetic dipole moment is coupled to alterations in solar activity as the system moves around the galactic center, then attribution of elevated carbon dioxide-temperature to human sources rather than actual etiologies can be counterproductive to adaptation.

Ray-tracing simulations of whistler-mode wave propagation in different rescaled dipole magnetic fields

Kinetic simulation is a powerful tool to study the excitation and propagation of whistler-mode waves in the Earth’s inner magnetosphere.This method typically applies a scaled-down dipole magnetic field to save computational time.However,it remains unknown whether whistler wave propagation in the scaled-down dipole field is consistent with that in the realistic dipole field.In this work,we develop a ray-tracing code with a scalable dipole magnetic field to address this concern.The simulation results show that parallel whistler waves at different frequencies gradually become oblique after leaving the equator and propagate in different raypaths in a dipole magnetic field.During their propagation,the higher frequency waves tend to have larger wave normal angles at the same latitude.Compared with the wave propagation in a realistic dipole field,the wave raypath and wave normal remain the same,whereas the wave amplification or attenuation is smaller because of the shorter propagation time in a scaled-down dipole field.Our study provides significant guidance for kinetic simulations of whistler-mode waves.

Quantification of the Diminishing Earth’s Magnetic Dipole Intensity and Geomagnetic Activity as the Causal Source for Global Warming within the Oceans and Atmosphere

Quantitative analyses of actual measurements rather than modeling have shown that “global warming” has been heterogeneous over the surface of the planet and temporally non-linear. Residual regression analyses by Soares (2010) indicated increments of increased temperature precede increments of CO2 increase. The remarkably strong negative correlation (r = -0.99) between the earth’s magnetic dipole moment values and global CO2-temperature indicators over the last ~30 years is sufficient to be considered causal if contributing energies were within the same order of magnitude. Quantitative convergence between the energies lost by the diminishing averaged geomagnetic field strength and energies gained within the ocean-atmosphere interface satisfy the measured values for increased global temperature and CO2 release from sea water. The pivotal variable is the optimal temporal unit employed to estimate the total energies available for physical-chemical reactions. The positive drift in averaged amplitude of geomagnetic activity over the last 100 years augmented this process. Contributions from annual CO2 from volcanism and shifts in averaged geomagnetic activity, lagged years before the measured global temperature-CO2 values, are moderating variables for smaller amplitude perturbations. These results indicated that the increase in CO2 and global temperatures are primarily caused by major geophysical factors, particularly the diminishing total geomagnetic field strength and increased geomagnetic activity, but not by human activities. Strategies for adapting to climate change because of these powerful variables may differ from those that assume exclusive anthropomorphic causes.

Quantification of the Diminishing Earth’s Magnetic Dipole Intensity and Geomagnetic Activity as the Causal Source for Global Warming within the Oceans and Atmosphere

Quantitative analyses of actual measurements rather than modeling have shown that “global warming” has been heterogeneous over the surface of the planet and temporally non-linear. Residual regression analyses by Soares (2010) indicated increments of increased temperature precede increments of CO2 increase. The remarkably strong negative correlation (r = -0.99) between the earth’s magnetic dipole moment values and global CO2-temperature indicators over the last ~30 years is sufficient to be considered causal if contributing energies were within the same order of magnitude. Quantitative convergence between the energies lost by the diminishing averaged geomagnetic field strength and energies gained within the ocean-atmosphere interface satisfy the measured values for increased global temperature and CO2 release from sea water. The pivotal variable is the optimal temporal unit employed to estimate the total energies available for physical-chemical reactions. The positive drift in averaged amplitude of geomagnetic activity over the last 100 years augmented this process. Contributions from annual CO2 from volcanism and shifts in averaged geomagnetic activity, lagged years before the measured global temperature-CO2 values, are moderating variables for smaller amplitude perturbations. These results indicated that the increase in CO2 and global temperatures are primarily caused by major geophysical factors, particularly the diminishing total geomagnetic field strength and increased geomagnetic activity, but not by human activities. Strategies for adapting to climate change because of these powerful variables may differ from those that assume exclusive anthropomorphic causes.

Eddy current effects in a high field dipole

Eddy currents produced by a time-varying magnetic field will introduce time delay and thus affect field quality. This effect leads to drifting of the beam position over time, especially for a compact synchrotron.Simulations and measurements of different dipoles have been performed, to investigate the time delay and field quality. The simulations are conducted using OPERA software. The measurements are conducted using a long coil and Hall sensor. All results show that the magnetic field deviation is up to 0.4% for the dipole with stainless steel endplates. The simulations show that the main sources of eddy current are the field saturation effect and the field component Bz, introduced by the bedstead-type coil. Field correction using a power supply is adopted to reduce the deviation to less than 0.02%.

Gauge Invariance of a Time-Dependent Harmonic Oscillator in Magnetic Dipole Approximation

非相对论的量力学的明白地计量器不变的明确的表达在磁性的偶极子近似被用于时间依赖者泛音振荡器的盒子。为获得计量器不变的转变概率振幅的一个一般方程被导出。

Basins of Attraction in the Copenhagen Problem Where the Primaries Are Magnetic Dipoles

We deal with the Copenhagen problem where the two big bodies of equal masses are also magnetic dipoles and we study some aspects of the dynamics of a charged particle which moves in the electromagnetic field produced by the primaries. We investigate the equilibrium positions of the particle and their parametric variations, as well as the basins of attraction for various numerical methods and various values of the parameter λ.

Changes of auditory evoked magnetic fields in patients after acute cerebral infarction using magnetoencephalography

Auditory evoked magnetic fields were recorded from 15 patients with acute cerebral infarction and 11 healthy volunteers using magnetoencephalography.The auditory stimuli of 2 kHz pure tone were binaurally presented with an interstimulus interval of 1 second.The intensity of stimuli was 90 dB and the stimulus duration was 8 ms.The results showed that the M100 was the prominent response, peaking approximately 100 ms after stimulus onset in all subjects.It originated from the area close to Heschl’s gyrus.In the patient group,the peak latency of M100 responses was significantly prolonged,and the mean strength of equivalent current dipole was significantly smaller in the affected hemisphere.The three-dimensional inter-hemispheric difference of the M100 positions was increased in the patient group.Our experimental findings suggested that impairment of cerebral function in patients with acute ischemic stroke can be detected using magnetoencephalography with the higher spatial resolution and temporal resolution.Magnetoencephalography could provide objective and sensitive indices to estimate auditory cortex function in patients with acute cerebral infarction.

A study on variations of non-dipole magnetic field over Chinese mainland during 2000 BC to 1990 AD

We calculated and analyzed variation of the non-dipole(ND)magnetic field at the millennium scale over the Chinese mainland during 2000 BC–1900 AD using the newest global geomagnetic model,CALS3K.4(3K.4).The newest-generation IGRF(IGRF11)was used to verify the results.Taking component Z for example,we calculated and analyzed the distribution and annual change rates of the ND field during 1900–1990 AD every 5 yr,using two models.To thoroughly analyze the contributions of field sources,quadrupole and octupole fields,and others within the ND field at the surface and core-mantle boundary(CMB)were investigated.Results show that there were three main variation phases of the field during the period 2000BC–1900 AD.The mean amplitude roughly reflected the ND field because of the distribution and variation of that field,corresponding somewhat to the mean amplitude change.A magnetic anomaly of the ND field over East Asia(EA)first emerged in 1682 AD,and its extreme intensity had increased a total of 15276.95 nT by 1900 AD.Its location moved continuously southeastward after 1690 AD.The asymmetry between location and intensity of extreme points over EA,particularly during1740–1760 AD,indicates irregularity of fluid motion inside the outer core.Mean annual changes of Z are generally divided into four phases,which first oscillated between 2000 and 800 BC,then increased,decreased and increased in the periods 800BC–300 AD,300–900 AD and 900–1900 AD,respectively.The intensity of mean annual change increased a total of 22.87nT/yr.Anomaly extreme locations based on 3K.4 and IGRF11 over EA centered around 44°N and 103°E for degree(n)greater than 5,and intensities continuously increased with n.During 2000 BC–1990 AD,ND energy of Z at the surface and CMB had decreased in total by 18.29%and 23.23%,respectively.The field source of 26–210 pole fields are more or less affected by the lithospheric field.Energies of higher degree at the surface attenuate by almost 99%compared with CMB,but mean attenuation speeds of the low-degree ND field are faster than high-degree,which implies that the low-degree ND field has a deeper source.

Numerical Experiment for Dipole-Dipole Interaction in Electro-Magnetism with Help of a Regular Tetrahedron

Aim of this work is to try to explain, on a Rational basis, some equations of Electro-Magnetism, which are based on Experimental data. Any Electric Field can produce a Field of many small Electric Dipoles, continuously distributed in space. In a region, where the Electric Field is constant, in direction and magnitude, all the small Dipoles are parallel to the Electric Field, and are represented by a single, long, parallel to them, fixed in space, Electric Dipole, which is here called Compass. An Alternating current, in a straight Conductor, is studied, by a simple, short computer program, for step-by-step nonlinear dynamic analysis. It is found that, only an Alternating current, not a direct current, can produce an Electric Dipole, in a straight Conductor. The two above Dipoles (Compass-Conductor) are assumed with equal lengths ℓ, lying on two skew lines, perpendicular to each other, at a distance ℓ√2, thus forming, by their four ends, a Regular Tetrahedron, with side length ℓ. Repulsion, between Like Charges, obeys the simple Coulomb Electro-Static law. Whereas Interaction (Attraction or Repulsion), between Unlike Charges, obeys a more accurate Lennard-Jones law. The analysis of Dipole-Dipole (Compass-Conductor) Interaction is performed by hand calculator. The only out-of-balance forces, in the regular Tetrahedron, acting on the Rigid Conductor, are the so-called magnetic forces. Their direction is found, in a simple Rational way, with help of Regular Tetrahedron, without recoursing to a “right-hand-rule”. The proposed model is applied to 1) The force acting on an Electric Charge moving in a magnetic field. 2) The force acting on a Current carrying straight Conductor, due to a magnetic field. 3) The magnetic fields created around a Current carrying straight Conductor. In these applications, proposed model gives reasonable results. Particularly, in third application, results, obtained by proposed model, are found in satisfactory approximation with corresponding ones, obtained by an empirical formula, based on relevant Experimental observations of H.-C. Oersted and A.-M. Ampère. So, the reliability of proposed model is checked. Position and direction of magnetic field vector coincide with those of a corresponding fixed Compass of a constant Electric Field. Main point of present work is that, without introducing the concept of a magnetic field vector, by combining field of dipoles, produced by an electric field, with dipole of an alternating current carrying conductor, the magnetic forces can be determined.

Effect of a Magnetic Field on an Atomic Orbital

We consider the effect of a magnetic field on the motion of an atomic electron in its orbit. The usual treatment deals with the change in magnetic dipole moment assuming the electron's speed changes but the radius of its orbit remains unchanged. We derive the change in the magnetic dipole moment allowing both the speed and the radius to change. The cases of fixed radius on one hand and of fixed speed on the other are treated as special cases of our general case.

水下无人潜航器内部磁场有限元仿真建模及其分布特性

针对水下无人潜航器(UUV)磁场分布特性的研究需求,利用有限元仿真软件COMSOL Multiphysics对UUV的磁场分布进行建模和仿真。分析UUV内部磁场来源及分布情况;对比分析磁偶极子理论计算与COMSOL磁场建模仿真,探讨利用COMSOL软件模拟方法开展磁场建模的可行性;运用COMSOL仿真软件,构建UUV几何模型,求解分析UUV平台干扰磁场分布特性。建模和仿真结果表明,利用COMSOL仿真软件实现磁偶极子建模是正确可靠的,UUV平台中后部磁感应强度最强,艏艉处磁感应强度最小,约为20 nT,为UUV平台的磁传感器安装位置和低磁性优化设计提供了依据。

Experimental Ferrogravitational Field around Untwisting Closed Superconductor

The study by the author of magnetic scattering neutrons in the structures of ferrimagnets, as well as his experiments with the separation of magnetic charges in dipole pairs ±g in magnetic field, showed that fundamental magnetic particles (magnetic charges) are real structural components of atoms and substance. It is the magnetic poles, and not the moving electric charges are the direct sources of all magnetic fields and magnetic manifestations in Nature. Basic reasons of ignoring the magnetic fundamental particles by world physical theory, for almost 150 years, are the ultra-harsh confinement of these particles in substance which radically is different from the confinement electrons, as well as the vicious concept of the electric magnetism Maxwell. Rotating magnetic dipoles in conductors which are untwisted by electric current, are direct sources of the vortex magnetic field rotH. One should also expect the formation of a vortex electric field rotE forming by rotating electric dipoles which are untwisted by the current of magnetic charges. This article provides an experimental answer to the question: what field is formed around a conductor if joint direct currents of electric Je and magnetic Jg charges are passed through it? The author’s experiments have shown that in this case the vortex electromagnetic current is realized which manifests itself as the vortex electromagnetic (gravitational) field. It is possible to implement such a process, according to the results of the author’s research, exclusively in superconductors. The vector character of the gravitational field is in many respects similar to the vortex magnetic field which makes it possible to introduce such it states as paragravitation and ferrogravitation into representations. To create joint currents of electric and magnetic charges, the author used the inertial forces of these particles under conditions of acceleration and deceleration of the rotational motion of the closed lead superconductor. The result of this experiment was the gravitational, as it turned out later, the ferrogravitational field, which was detected by effect repulsion of trial cargos from the coil with a superconducting winding at the stage of its untwist. The latter process is defined by the author as an effect of the gravitational (ferrogravitational) levitation. The values of ferrogravitational (levitational) forces noted in this experiment were: 120 mg for a tungsten trial cargo and 50 and 25 mg for a lead cargo with an error of ±15 mg. The values of ferrogravitational (levitational) forces noted in this experiment are: 120 mg for from tungsten trial cargo and 50 and 25 mg for a cargo from lead, with an error of ±15 mg. The “anomaly” noted by the author in this study was in the absence of any absence of a gravitational effect on stage a braking of the coil. Probable cause of the noted “anomaly” is discussed in the Discussion of Results chapter.

2D and 3D Analysis of Magnetocardiographic Data in the Evaluation of the Ventricular Repolarization Changes under Exercise Stress Test in Patients with CAD

Objective: Non-invasive methods of evaluation of electrical activity of the heart are still the most important functional diagnostics methods in coronary artery disease (CAD) detection. It has been shown that magnetocardiography (MCG) appears to be rather sensitive in diagnostics of chronic CAD even in the patients at rest with unchanged ECG. The objective of present paper is to investigate the influence of non-invasive tests with a physical exerciseon MCG parameters in the patients with chronic CAD. Materials and Methods: In total, 10 patients were examined (mean age 41 ± 5 years) suffering from chronic stable angina (CAD). CAD was diagnosed by clinical evidences, bicycle ergometria positive data and coronary angiography (stenosis > 70% in at least onr main coronary angiography). The control group consisted of 14 healthy volunteers. MCG mapping was performed by means of a 7-channel SQUID-magnetometer installed in an unshielded room. The MCG examination was conducted twice, whilst patients were at rest and after exercise on the bicycle (in healthy persons it was conducted immediately after exercise and in the patients, after the ST depression and/or chest pain had disappeared). The homogeneity and electric motive force (EMF) direction disturbances on magnetic field distribution maps on an extent of ST-T interval have been evaluated. Results: Statistically significant differences between groups examined based both on 2D and 3D quantitative criteria were demonstrated. Conclusion: The application of a set of MCG criteria based on the analysis both of ventricular depolarization and repolarization will enable a greater degree of accuracy for the results of the exercise stress test, especially in doubtful cases.

基于磁散射的线膛炮内表面磨损检测技术

针对线膛炮使用过程对身管内表面磨损检测的需求,建立线膛炮内表面磨损磁散射模型,研究一种线膛炮内表面磨损检测方法。在地磁环境中,基于磁偶极子模型分析阴线双侧膛线壁的二维磁偶极子模型,推导内膛、导转侧、烧蚀沟、镀层等磨损的散射磁场分布模型,通过仿真得到身管内表面磨损的磁场分布变化规律,对膛线磨损检测进行了半实物模拟试验。实验结果表明:当阳线无磨损时,阴线与阳线磁场强度差值为17.6 A/m;当阳线磨损为56.15%时,磁场强度差值减小到1.78 A/m;该方法为身管出厂和使用提供一种膛线磨损检查理论与方法。

基于多偶极子磁性模型的卫星复杂磁场建模方法

飞行器、舰船和潜艇等典型可移动平台具有复杂的磁场,获取这些磁场信息对于提高磁场探测精度具有重要意义。文章在简要总结典型可移动平台复杂磁场的建模方法基础上,结合卫星自身特点,提出基于多偶极子磁性模型的卫星复杂磁场快速建模方法。其技术途径有两种:一是基于单机磁试验数据建立单机磁性模型,再组合成整星多偶极子磁性模型;二是基于卫星磁试验数据直接建立整星多偶极子磁性模型。采用这两种技术途径完成某型号卫星的磁场建模、计算与测量验证,测试结果表明多偶极子法可很好地适用于磁洁净卫星复杂磁场的快速建模计算,精度优于0.2 nT。

一种强电磁设备低频辐射特性等效建模方法

随着高开关频率的新型电力电子器件广泛应用到舰船等平台上的强电磁设备中,强电磁设备产生的低频辐射会对平台上的敏感设备产生严重的影响,因此必须对强电磁设备的低频辐射特性进行准确建模表征,支撑开展强电磁设备低频场分布特征的量化预测,以便提升整个平台的电磁兼容性能。传统等效偶极子法在对大尺寸辐射源进行等效建模时,存在偶极子阵列所需的等效偶极子源数量多,高度、位置选择困难等问题。为解决上述问题,该文提出一种基于自适应差分进化算法的强电磁设备低频辐射特性等效偶极子建模的方法。该方法从强电磁设备附近的近场辐射特性测试数据出发,将强电磁设备低频辐射等效为分布在多个区域的偶极子阵列组合的分布式辐射源,并通过自适应差分进化算法优化各区域偶极子阵列的数量、位置以及高度等等效源参数,并通过试验和算例验证该方法可在满足一定精度条件下,能大幅度减小偶极子数量,得到强电磁设备最优的低频分布式等效源模型。

基于磁偶极子的磁信标标定方法

针对磁信标产生的超低频磁场定位中磁信标磁场中心难以标定的问题,提出了一种基于磁偶极子磁感应强度分布特征的高精度磁信标标定方法。为描述磁信标在空间中任意位置产生的磁场分布情况,建立磁信标的等效磁偶极子模型,通过磁感应强度不同方向的分量与位置关系解算出磁信标线圈磁场的中心位置,利用自适应指数平滑算法减弱自身波动对磁感应信号的影响,实现对磁信标磁场中心的高精度标定。对标定方法进行有限元仿真,仿真结果显示,使用磁感应强度分布特征对磁场中心的标定精度在毫米级别,通过对标定前后定位精度的对比发现,标定后的磁信标定位精度得到有效提高。