Possible Mechanism of Plasticity Influenced by Magnetic Field

The strain energy of an edge dislocation in an external static magnetic field is determined by the theory of elasticity and electrodynamics according to the Volterra dislocation model for continuous media. The results show that the strain energy of the edge dislocation in paramagnetic states is increased due to static magnetic field and the increase in the energy of the dislocation is capable of influencing the dislocation depinning which leads to the change of plasticity. This gives an explanation on plasticity induced by magnetic field.     

A Mechanism for Generation of the Solar Magnetic Field

We apply the mathematical technique of quantum mechanics for studying the process of solar magnetic field generation under conditions where the viscosity is negligible and the rotation velocity of the medium is independent of time. It is assumed that the magnetic field is almost toroidal, axially nonsymmetric, and antisymmetric with respect to the equatorial plane.We show that in the presence of an axisymmetric poloidal component of the hydrodynamic velocity and a radial gradient of the angular velocity of the medium, an oscillating solution growing in time exists for the field. The characteristic frequency of oscillations can exceed the rotation frequency if the rotation of the medium is nonuniform. In the case where the characteristic time of field growth amounts to 10 years, the radial velocity of the medium in the field-generation zone is approximately equal to 10 cm/sec. We also discuss briefly the problem of the existence of two field-generation zones.     

A Possible Origin of Quantum Correlations

We intend to eliminate the known conflict between relativity and quantum mechanics. We believe the “instant” correlation between entangled distant quantum particles can be explained by the fact that in a laboratory reference frame the photon traveling duration is positive and finite while its proper (in vacuum) traveling duration is equal to zero. In the latter case, any two events that are separated (in a laboratory reference frame) by an arbitrary finite distance can be considered as simultaneous ones. So, the photon nonlocal correlation turns out to be a relative property and may be explained like known twins paradox in relativity. In such a situation, any standard causal interaction between the correlated particles is absent in a laboratory reference frame; however, some specific mutual couple appears between them; this couple is strictly oscillating without some oriented energy or/and information transferring. We also motivate the basic hypothesis extension on quantum particles having nonzero masses.     

外加磁场下铁的形核机理

本文采用直接冷却和两相模拟两种分子动力学方法,研究了外加磁场液态铁凝固过程的影响并将结果与无外加磁场的计算结果进行对比. 外加磁场对凝固过程的影响主要体现在临界温度、能量和径向分布函数. 计算结果表明,铁液的凝固相变过程主要是发生在1500∽1600 K的温度范围;在外加磁场作用下,液态铁的凝固点有明显减小的趋势. 通过对扩散系数和粘度的进一步分析,在外加磁场的存在下,体系的扩散系数增大而粘度减小,研究显示外磁场驱动的铁液原子涨落较强导致凝固点的降低.     

Numerical Simulation on a Possible Formation Mechanism of Interplanetary Magnetic Cloud Boundaries

The formation med2aniRm of the interplanetary magnetic cloud (MC) boundaries is numerically investigated by simulating the interactions between an MC of some initial momentum and a local interplanetary current sheet.The compressible 2.51:) MHD equations are solved. R~sults show that the magnetic reconnection process is a possible formation mechanism when an MC interacts with a surrounding current sheet. A number of interesting features are found. For instance, the front boundary of the MCs is a magnetic reconnection boundary that could be caused by a driven reconnection ahead of the cloud, and the tail boundary might be caused by the driving of the entrained flow as a result of the Bernoulli principle. Analysis of the magnetic field and plasma data demonstrates that at these two boundaries appear large value of the plasma parameter β, clear increase of plasma temperature and density, distinct decrease of magnetic magnitude, and a transition of maguetic field direction of about 180 degrees. The outcome of the present simulation agrees qualitatively with the observational results on MC boundary inferred from IMP-8, etc.     

Numerical Simulation on a Possible Formation Mechanism of Interplanetary Magnetic Cloud Boundaries

The formation mechanism of the interplanetary magnetic cloud (MC) boundaries is numerically investigatedby simulating the interactions between an MC of some initial momentum and a local interplanetary current sheet.The compressible 2.5D MHD equations are solved. Results show that the magnetic reconnection process is a possibleformation mechanism when an MC interacts with a surrounding current sheet. A number of interesting features arefound. For instance, the front boundary of the MCs is a magnetic reconnection boundary that could be caused by adriven reconnection ahead of the cloud, and the tail boundary might be caused by the driving of the entrained flowas a result of the Bernoulli principle. Analysis of the magnetic field and plasma data demonstrates that at these twoboundaries appear large value of the plasma parameterβ, clear increase of plasma temperature and density, distinctdecrease of magnetic magnitude, and a transition of magnetic field direction of about 180 degrees. The outcome of thepresent simulation agrees qualitatively with the observational results on MC boundary inferred from IMP-8, etc.     

A Toroidal Magnetic Field Theorem

In the framework of magnetohydrodynamics the kinematic dynamo problem in a spherical fluid volume as well as in a plane layer is considered. On the premises of a purely toroidal magnetic field a nonlinear evolution equation for the toroidal scalar is derived. In this equation the flow field is constrained in such a way that no poloidal magnetic field can arise, but is otherwise arbitrary; the magnetic diffusivity is assumed to be spherically (horizontally, resp.) symmetric. Solutions of this problem are of particular interest since the magnetic field is confined to the fluid volume and therefore invisible to an external observer. It is proved in this paper that the maximum norm of smooth solutions of this equation decays exponentially fast to zero. Thus, dynamo solutions, i.e. nondecaying solutions, of this type do not exist.     

用Origin7.5处理霍尔效应测量螺线管轴向磁场的实验数据

通过用Origin7.5处理霍尔效应测量螺线管轴向磁场实验的三方面的数据,体现该软件在处理数据统计和绘图功能上的简便操作性。     

A Probable Origin and Radiation Mechanism for Gamma-Ray Bursts

A model of the old and hot neutron stars (age γ～10⁸～10⁹ yr, temperature T_N～10⁷-10⁸ K) with the low magnetic field (B～10⁹-10¹⁰ Gauss) as the sources of Gamma-ray bursts is presented. In the range of medium energy (E < 400 KeV), the main radiation mechanism is still the thermal synchrotron radiation. The absorp tion features of the low frequency (E < 50 KeV) are resulted from the superposition of the blackbody spectrum emitted by the hot neutron star itself and the thermal synchrotron spectrum with self-absorption. And the spectrum for the high energy part (E > 400 KeV, including the emission features) is due to the annihilation emission from the unthermalized positrons and electrons. Using this model, we adopt the three component spectra to fit four representative spectra of Gamma-ray bursts. The results are satisfactory. Our model also avoids some difficulties existed in other modela.     

A Possible Cause of Magnetic Anomalies on the Southern Martian Hemisphere

From the topology of a synthetic aurora map,we propose a mechanism for the magnetic anomalies on the southern martian hemisphere,i.e.,impacts by asteroids when the dynamo is active.The quasi concentric circles of aurora suggest that there are two-to-three convectional cells for each impact.The whole synthetic aurora is induced by three major impacts of asteroids.The east-west lineation features of crust magnetizations are due to the east-west trending locations of three impacts.The alternatively changed sign of crust magnetization originates from the alternatively changed Bow direction on the tops of adjacent convectional cells.     

Effect of Magnetic Field on the Nanohardness of Monocrystalline Silicon and Its Mechanism

The effect of magnetic field on the nanohardness of monocrystalline silicon doped with phosphorous by ion implantation is studied. It is found that a magnetic field of certain parameters can increase the nanohardness of monocrystalline silicon doped with phosphorous by ion implantation, and this increase can be eliminated by annealing monocrystalline silicon doped with phosphorous by ion implantation at 800°C for 780 s. For the monocrystalline silicon doped with phosphorous by ion implantations that have not been exposed to a magnetic field, annealing them at 800°C for 780 s cannot affect their nanohardness, but exposing them to the magnetic field mentioned previously can no longer affect their nanohardness after annealing. The mechanism of all these phenomena is discussed. A possible mechanism that a magnetic field can promote the disbanding of vacancy clusters, and a possible mechanism of magnetically stimulated clusters’ disbanding and magnetoplastic effect are put forward.     

A Possible Macroscopic-Photo-Catalysis Mechanism in Solar Furnace

Based on the experimental results of Chen et al. to use the solar furnace and medium frequency induction furnace to extract boron impurity from metallurgical silicon, we propose a strong radiation catalysis mechanism to explain the difference of reaction rates in these two furnaces. The postulate assuming the photons striking on the material not only increase the thermal energy of the molecules of reactants but also lower down the energy barrier of the reaction to speed up the chemical reaction. It is believed the photon catalysis mechanism is universal in most of high temperature chemical reactions and looking forward to more evidences for the postulate proposed in this article.     

A Possible Origin of e+e- Peaks in Heavy-Ion Collisions

The behavior of a neutral composite particle composed of a positron and an electron in the strong Coulomb field of a nuclear uquasimolecule formed in low-energy heavy-ion collions is examined. A strong attractive interaction between the composite particle and the Coulomb field is found when the combined nuclear charge of two nuclei is sufficiently large, which is possible to lead to the e⁺e^- pair production in heavy-ion collisions.     

Origin 8.5在亥姆赫兹线圈磁场测量实验数据处理中的应用

与传统的人工处理实验数据相比,Origin8.5软件处理实验数据具有方便快捷、直观、精度高等特点。文中通过使用Origin8.5软件处理亥姆赫兹线圈测磁场实验的数据,详细介绍了二维绘图、三维绘图以及非线性曲线拟合的过程,结果表明使用Origin8.5软件处理实验数据能有效的减少人工处理带来的误差。     

A Possible Pairing Mechanism in Two-Band Hubbard Model

A theoretical scheme for describing the quasiparticle-pair superconductivity in doped CuO₂ system is suggested based on the model put forward by Emery and Reiter. The doped O holes and associated two neighboring Cu-spins form spin-1/2 quasiparticles. Through the magnetic interaction with the spin background, the quasiparticles interact with each other and lead to pair condensation which is responsible for the superconductivity.     

一种新型的基于磁性液体的光纤Sagnac磁场传感器

提出一种使用磁性液体的新型光纤Sagnac磁场传感器.磁性液体具有磁致可变双折射效应和二向色性,在外加磁场作用下,液体中的磁性纳米粒子沿磁场方向结链规则排列,形成各向异性.将其制成液体薄膜,放入具有一段保偏光纤的Sagnac环中,使光纤Saganc干涉仪的正弦形状干涉光谱可随外磁场变化.光纤中传输光垂直经过磁性液体薄膜...     

NMR in Magnetic Field of the Earth: Pre-Polarization of Nuclei with Alternating Magnetic Field

The polarization of nuclei in the low static magnetic field \(B_0\) with an alternating magnetic field \(B^{*} (B^{*} \gg B_0)\) at a very low frequency \(f_m\) (but \(f_m\gg 1\) / \({T_1}\) , where \(T_1\) is the spin-lattice relaxation time) has been investigated. The question of the optimization of the energy consumption during the pre-polarization is also considered. The possibilities of the method are illustrated by the observation of nuclear magnetic resonance signals from a few liquids.     

磁传感器与磁场的测量

在中学物理教学中，研究磁场传统的实验方法是用小磁针显示磁场的方向，用小磁针或铁粉显示磁感线分布．磁针和铁粉用来形象描述磁场功不可没，可对磁感强度的定量研究却显得无能为力．学生也只好在题海中领会感受磁感强度B的大小；1特斯拉有多大?在脑子里只有一个模糊抽象的印象．物理学对电磁现象的研究成果为各行各业提供了先进的检测设备，可是在自身的物理教学中对磁场的实验检测仍停留在4大发明的“司南”时代．近来上海的DIS实验(数字化实验系统)，