Direct Generation of Intense Compression Waves in Molten Metals by Using a High Static Magnetic Field and Their Application

Compression waves propagating through molten metals are contributed to degassing, accelerating reaction rate,removing exclusions from molten metals and refining solidification structures during metallurgical processing of materials. In the present study, two electromagnetic methods are proposed to generate intense compression wavesdirectly in liquid metals. One is the simultaneous imposition of a high frequency electrical current field and a staticmagnetic field; the other is that of a high frequency magnetic field and a static magnetic field. A mathematical modelbased on compressible fluid dynamics and electromagnetic fields theory has been developed to derive pressure distributions of the generated waves in a metal. It shows that the intensity of compression waves is proportional to thatof the high frequency electromagnetic force. And the frequency is the same as that of the imposed electromagneticforce. On the basis of theoretical analyses, pressure change in liquid gallium was examined by a pressure transducerunder various conditions. The observed results approximately agreed with the predictions derived from the theoreticalanalyses and calculations. Moreover, the effect of the generated waves on improvement of solidification structureswas also examined. It shows that the generated compression waves can refine solidification structures when they wereapplied to solidification process of Sn-Pb alloy. This study indicates a new method to generate compression wavesby imposing high frequency electromagnetic force locally on molten metals and this kind of compression waves canprobably overcome the difficulties when waves are excited by mechanical vibration in high temperature environments.

Influence of Magnetic Field on the Rectification Process of Binary Heterogeneous Azeotrope

To improve separate effect of binary heterogeneous azeotrope in the magnetic field with different magnetic induction intensity, the influence of magnetic field on the rectification process of binary heterogeneous azeotrope was investigated with l-butanol-water system. The results show that the composition of liquid-liquid phase equilibrium of l-butanol-water system has definitely changed, the composition of l-butanol in light phase （l-butanol layer） increases by 1. 17%-1.63% and the composition of water in heavy phase （water layer） increases by 1.21%-1.58% under the influence of magnetic field. By separation of magnetization, the composition of l-butanol increases by 0.8%-1.2% and the recovery ratio of 1 -butanol increases by 1.6%-2.5%. Magnetic field has positive effect, however, the magnetized effect is not in proportion to magnetic induction intensity and has an optimum condition, in the range of 0.25 T-0. 3 T.

The Drift of Dust Grains Induced by Transient Magnetic Field

Our experiment shows that the dust grains, suspended on the edge of the sheath of a radio-frequency discharge, undergo a contraction when switching a vertical magnetic field on, and an expansion when switching the magnetic field off. We call this kind of magnetic field "transient magnetic field". A primary analysis is proposed for the phenomenon.

Investigate the Effect of the Magnetic Field on the Mechanical Properties of Silicone Rubber-Based Anisotropic Magnetorheological Elastomer during Curing Process

In this investigation,a new silicone rubber-based MRE material was prepared to be used as a forming medium in manufacturing thin-walled complexshaped Ni-based tubes through the bulging process.Thus,it is significant to investigate the effect of magnetic field intensity,magnetic field loading time,and angle on the mechanical properties of the prepared MRE material during the curing process.The obtained results showed that increasing the magnetic field intensity during the curing process can improve the orientation of the chain structure in the elastomer matrix effectively.However,its mechanical properties are the best under the corresponding magnetic field intensity of 321 mT.Besides,by extending the magnetic field loading time in the curing process,the orientation of the chain structure was optimized,at the same time,the mechanical properties were also improved,and the best loading time is about 20–25 min.By changing the loading angle of the magnetic field during the curing process,the mechanical properties of the MRE were improved.When the loading angle of the magnetic field is 90°,the elastomer showed the best compression mechanical properties and excellent compression reversibility.Besides,for the anisotropic MRE material,the performance with magnetic compression is always better than that without magnetic compression.

Lossless Compression Method for the Magnetic and Helioseismic Imager(MHI)Payload

The Solar Polar-orbit Observatory(SPO),proposed by Chinese scientists,is designed to observe the solar polar regions in an unprecedented way with a spacecraft traveling in a large solar inclination angle and a small ellipticity.However,one of the most significant challenges lies in ultra-long-distance data transmission,particularly for the Magnetic and Helioseismic Imager(MHI),which is the most important payload and generates the largest volume of data in SPO.In this paper,we propose a tailored lossless data compression method based on the measurement mode and characteristics of MHI data.The background out of the solar disk is removed to decrease the pixel number of an image under compression.Multiple predictive coding methods are combined to eliminate the redundancy utilizing the correlation(space,spectrum,and polarization)in data set,improving the compression ratio.Experimental results demonstrate that our method achieves an average compression ratio of 3.67.The compression time is also less than the general observation period.The method exhibits strong feasibility and can be easily adapted to MHI.

Derivation of the Equation Nernst-Aibassov in a Magnetic Field

The influence of magnetic field on the redox potentials of the Nernst equation. The author offered the new formula Nernst equation in a magnetic field. Our proposed formula takes into account the influence of the magnetic field on the redox processes.

NUMERICAL SIMULATION OF TEMPERATURE FIELD DURING MAGNETIC FIELD QUENCHING

Based on the theories of the heat transfer, the principle of phase transformation and the theory of electric and magnetic field, the mathematical model of transient temperature field involving phase transformation during magnetic field quenching is established. The heat exchange equation including magnetic field is founded. The finite element equation is set up. The distributing of transient temperature on the coupling effects of heat and magnetism is obtained. With test and measurement, the results show that after magnetic field quenching, cooling velocity is decreased, cooling curve is flatten out, and the hardness is slightly raised.

Study on traveling magnetic field casting of sheet components

The distribution of a magnetic field over an inductor used for sheet castings has been investigated experimentally.With an increase in height from the surface, the magnetic field density decreases according to the exponential law.In the transverse direction, the magnetic field density is approximately uniform except near the edges.The magnetic field density is direct proportional to the number of turns multiplied by the current in amperes.Ferro-magnetic material in the upper mould can enhance the magnetic field density.Under the electromagnetic force, the mould-filling process of sheet casings has been studied by physical simulation method.The difference in filling capability between gravity casting and travelling magnetic field casting has been studied.The electromagnetic force can enhance the filling process, but it also brings a problem.With an increase in the magnetic field density, the surface quality of the aluminum alloy sheet castings becomes poor.The reason is discussed.

Can we determine the filament chirality by the filament footpoint location or the barb-bearing？

We attempt to propose a method for automatically detecting the solar filament chirality and barb beating. We first introduce the concept of an unweighted undirected graph and adopt the Dijkstra shortest path algorithm to recognize the filament spine. Then, we use the polarity inversion line （PIL） shift method for measuring the polarities on both sides of the filament, and employ the connected components labeling method to identify the barbs and calculate the angle between each barb and the spine to determine the bearing of the barbs, i.e., left or right. We test the automatic detection method with Ha filtergrams from the Big Bear Solar Observatory （BBSO） Ha archive and magnetograms observed with the Helioseismic and Magnetic Imager （HMI） on board the Solar Dynamics Observatory （SDO）. Four filaments are automatically detected and illustrated to show the results. The barbs in different parts of a filament may have opposite bearings. The filaments in the southern hemisphere （northern hemisphere） mainly have left-bearing （fight- bearing） barbs and positive （negative） magnetic helicity, respectively. The tested results demonstrate that our method is efficient and effective in detecting the bearing of filament barbs. It is demonstrated that the conventionally believed one-to-one correspondence between filament chirality and barb bearing is not valid. The correct detection of the filament axis chirality should be done by combining both imaging morphology and magnetic field observations.

Model of the singular current source—The indicator of geodynamic processes in Japan in 2009-2011

The calculation method of the location of the singular generalized current source according to synchronous measurements of the magnetic field in the remote points is proposed. It is designed for the continuous monitoring of changes of the degree of electromagnetic heterogeneity of the geophysical environment. Regular fluctuations of the apparent distance to the effective single source were recorded according to the magnetic data of the observatories in Japan 2009-2011. They are connected with the rhythm of the geodynamic processes in the vicinity of the station Kakioka. The most significant decrease in the apparent distance was registered in connection with the seismic activation of the region, including the catastrophic earthquake of March 11, 2011 with a magnitude of M = 9.1. The anomalous behavior of the apparent parameters of the generalized source was displayed not less than two weeks before the earthquake. Characteristic changes of the curves were registered in the period of three months.

Superconducting multipole wiggler with large magnetic gap for HEPS-TF

A 16-pole superconducting multipole wiggler with a large gap of 68 mm was designed and fabricated to serve as a multipole wiggler for HEPS-TF.The wiggler consists of 16 pairs of NbTi superconducting coils with a period length of 170 mm,and its maximum peak field is 2.6 Tesla.In magnet design,magnet poles were optimized.Furthermore,the Lorentz force on the coils and electromagnetic force between the upper and lower halves were computed and analyzed along with the stored energy and inductance at different currents.To enhance the critical current of the magnet coil,all the pole coils selected for the magnet exhibited excellent performance,and appropriate prestress derived from the coil force analysis was applied to the pole coils during magnet assembly.The entire magnet structure was immersed in 4.2-K liquid helium in the cryostat cooled solely by four two-stage cryocoolers,and the performance test of the superconducting wiggler was appropriately completed.Based on the measured results,the first and second field integrals on the axis of the superconducting wiggler were significantly improved at different field levels after the compensation of the corrector coils.Subsequently,the wiggler was successfully installed in the storage ring of BEPCII operation with beams.

Identification and classification of transient pulses observed in magnetometer array data by time-domain principal component analysis filtering

A method for identification of pulsations in time series of magnetic field data which are simultaneously present in multiple channels of data at one or more sensor locations is described. Candidate pulsations of interest are first identified in geomagnetic time series by inspection. Time series of these ＂training events＂ are represented in matrix form and transpose-multiplied to generate time- domain covariance matrices. The ranked eigenvectors of this matrix are stored as a feature of the pulsation. In the second stage of the algorithm, a sliding window （approxi- mately the width of the training event） is moved across the vector-valued time-series comprising the channels on which the training event was observed. At each window position, the data covariance matrix and associated eigen- vectors are calculated. We compare the orientation of the dominant eigenvectors of the training data to those from the windowed data and flag windows where the dominant eigenvectors directions are similar. This was successful in automatically identifying pulses which share polarization and appear to be from the same source process. We apply the method to a case study of continuously sampled （50 Hz） data from six observatories, each equipped with three- component induction coil magnetometers. We examine a 90-day interval of data associated with a cluster of four observatories located within 50 km of Napa, California, together with two remote reference stations-one 100 km to the north of the cluster and the other 350 km south. When the training data contains signals present in the remote reference observatories, we are reliably able to identify and extract global geomagnetic signals such as solar-generated noise. When training data contains pulsations only observed in the cluster of local observatories, we identify several types of non-plane wave signals having similar polarization.

Beta decay of nuclides ^(56)Fe,^(62)Ni,^(64)Ni and ^(68)Ni in the crust of magnetars

By introducing the Dirac δ-function and Pauli exclusion principle in the presence of superstrong magnetic fields （SMFs）, we investigate the influence of SMFs on beta decay and the change rates of electron fraction （CREF） of nuclides 56Fe, 62Ni, 64Ni and 6SNi in magnetars, which are powered by magnetic field energy. We find that the magnetic fields have a great influence on the beta decay rates, and the beta decay rates can decrease by more than six orders of magnitude in the presence of SMFs. The CREF also decreases by more than seven orders of magnitude in the presence of SMFs.

Strong screening effects on resonant nuclear reaction ^(23)Mg(p,γ) ^(24)Al in the surface of magnetars

Based on the theory of relativistic superstrong magnetic fields （SMFs）, by using the method of Thomas-Fermi-Dirac approximations, we investigate the problem of strong electron screening （SES） in SMFs and the influence of SES on the nuclear reaction of 23Mg （p, Y）24A1. Our calculations show that the nuclear reaction will be markedly effected by the SES in SMFs in the surface of magnetars. Our calculated screening rates can increase two orders of magnitude due to SES in SMFs.

Recovery of Silver from Cyanide Solutions Using Electrochemical Process Like Alternative for Merrill-Crowe Process

The conventional processes for recovery of silver from cyanide leach solutions are the carbon adsorption, the Merrill-Crowe zinc dust cementation, the Ion Exchange, and Solvent Extraction processes;among other available options for recovery of precious metals from cyanide solutions, Electrocoagulation (EC) is a very promising electrochemical process that does not require high concentrations of silver in cyanide solutions to yield excellent results and neither pretreatment of cyanide solutions like Merrill-Crowe process (deoxygenating and clarification). The present study has been done for the recovery of silver contained in pregnant solution from the cyanidation process using the electrocoagulation technology with iron electrodes, and therefore develops an alternative technology for Merril-Crowe process. The average silver content in pregnant solution was of 52 ppm, recovery was obtained of 99% of silver, with this optimum operating parameters, pH = 8, residence time = 20 minutes and conductivity by addition of sodium chloride = 4 grs/L. Finally the characterization of the solid products formed during the EC process with X-ray Diffraction and Scanning Electronic Microscope was performed, results suggest that magnetite particles and amorphous iron oxyhydroxides are present (Lepidocrocite).

Neutron （Magnetic Isotope） Catalysis for Example Isotopes 24,25,26Mg in Cells E. Coli

We offered the new theory of neutron （magnetic isotope） catalysis. For the first time it was shown that the number of neutrons in the atom, which have anomalous magnetic effect, have a great influence on the chemical properties. Our proposed theory of neutron （magnetic isotope） catalysis takes into account the influence of the magnetic field on the catalytic processes.

马蹄脆片微波真空干燥工艺优化及其水分变化

以马蹄为原料,采用微波真空干燥技术干燥马蹄脆片,考察微波功率、干燥温度、真空度、切片厚度对马蹄脆片色差值、总糖含量、脆度的影响,以响应面试验优化干燥工艺,采用低场核磁共振技术研究马蹄脆片干燥过程水分变化情况。结果表明,微波真空干燥马蹄脆片的最佳工艺为微波功率2.0 kW、干燥温度71℃、真空度-95 kPa、切片厚度3.1 mm,所得产品色差值、总糖含量、脆度分别为3.42、50.51 mg/100 g、464.96 g,产品色泽白亮,酥脆可口,马蹄风味浓厚。低场核磁共振检测结果表明:马蹄片内部主要存在3种状态水,分别是自由水、不易流动水及结合水,其中自由水占比较高、结合水和不易流动水的比例相对较低,在最佳工艺下到达干燥终点时自由水完全除去,只剩少量的不易流动水以及结合水。

磁场强化非均相分离技术的工业应用进展

概述了磁场分离技术在分离多相混合介质中的研究和应用进展,对磁场分离技术的应用原理和分离优势进行了分析。根据混合相内的介质类别,分别针对固、液、气不同应用领域,介绍了磁场分离工艺在矿物精选、污水处理、气体除杂中的典型应用,并分析了相应运行工况下的磁场排布规律和介质分离特性。从组合工艺的研究视角出发,总结了磁场分离技术与气浮分离技术、膜分离技术、旋流分离技术的耦合应用现状,并分析了上述组合工艺的技术特点、运行成效。为拓宽磁场分离技术的适用范围,讨论了磁种在磁场分离工艺中的辅助应用,以强化该技术对无磁性介质的分离。

组合式电磁成形技术研究进展

电磁成形技术是一种典型的高速率电磁脉冲成形技术,可显著地提高材料的延展性,减小工件回弹和起皱,降低设备制造成本。在电磁成形技术发展过程中,电磁成形力场的有效加载和调控颇具挑战,早期的电磁成形方案基本实现工件排斥力成形效果,其电磁力分析中主要以排斥力占据主导,应用有较大的局限性,如今优势明显的组合式电磁成形技术开始进入大众视野。该文在简述电磁成形基本原理及电磁力调控方式的基础上,根据组合式方法应用的不同层面,将近年来涌现的研究成果划分为:驱动线圈组合式、电磁力组合式及工艺组合式三类电磁成形技术,针对每一类技术,分别阐述了其实施原理、技术方案及应用成效,并进一步归纳了不同技术的适用范围及研究重点。最后,在这些研究成果的基础上,对组合式电磁成形技术未来的发展方向进行了展望。

磁环境下AAO工艺中的微生物群落演替规律

将AAO反应器置于5 mT大小的平均磁场环境,文中研究了磁场对AAO工艺效能的影响,并从分子生物学的角度对其影响机理进行了初步探究。结果表明,在5 mT磁场环境下,AAO工艺启动阶段的平均总氮去除率有较明显提升,比对照组上升6%;AAO反应器启动时间较对照组缩短了5 d;AAO中以固氮螺旋菌(Azospira)为代表的反硝化菌群的相对丰度占比明显提升,丝硫菌属(Thiothrix)的相对丰度占比大幅降低,对污泥膨胀的抑制作用较明显;通过基因功能预测发现磁环境下细胞运动类基因相对丰度相对无磁场条件提升75%,膜运输类基因大幅下降,从而提高了AAO的启动速度,提升了脱氮效能。