A wide range of industrial metallurgical heating and melting processes are carried out using electrothermal and electromagnetic technologies.The application of electromagnetic processing offers many advantages from te...A wide range of industrial metallurgical heating and melting processes are carried out using electrothermal and electromagnetic technologies.The application of electromagnetic processing offers many advantages from technological, ecological and economical point of view.Although the technology level of the electromagnetic heating and melting installations and processes used in the industry today is very high,there are still potentials for improvement and optimization.In this paper recent applications and future development trends for efficient use of electromagnetic processing technologies in metallurgical and non-metallic material processes are described along selected examples in the field of heating for melting,forging,joining and solidification.展开更多
Pulsed external field, including electric, magnetic, ultrasonic and laser, as aninstantaneous high energy input method with high efficiency and low energyconsumption, have long been known to can modify the microstruct...Pulsed external field, including electric, magnetic, ultrasonic and laser, as aninstantaneous high energy input method with high efficiency and low energyconsumption, have long been known to can modify the microstructure and propertiesof materials. This includes electroplasticity, magnetoplasticity, phase transformations,recrystallization, grain refinement, texture control, inclusion removal.展开更多
Introduction Cationic starches are a series of products of which various sorts with different properties and usages can all be produced via cationic reactions by using different types of etherification agents under di...Introduction Cationic starches are a series of products of which various sorts with different properties and usages can all be produced via cationic reactions by using different types of etherification agents under different conditions. As an additive and strengthening agent,展开更多
A microwave thruster system that can convert microwave power directly to thrust without a gas propellant is devel-oped. In the system, a cylindrical tapered resonance cavity and a magnetron microwave source are used r...A microwave thruster system that can convert microwave power directly to thrust without a gas propellant is devel-oped. In the system, a cylindrical tapered resonance cavity and a magnetron microwave source are used respectively as the thruster cavity and the energy source to generate the electromagnetic wave. The wave is radiated into and then reflected from the cavity to form a pure standing wave with non-uniform electromagnetic pressure distribution. Consequently, a net electromagnetic thrust exerted on the axis of the thruster cavity appears, which is demonstrated through theoretical calcula- tion based on the electromagnetic theory. The net electromagnetic thrust is also experimentally measured in the range from 70 mN to 720 mN when the microwave output power is from 80 W to 2500 W.展开更多
Compression waves propagating through molten metals are contributed to degassing, accelerating reaction rate,removing exclusions from molten metals and refining solidification structures during metallurgical processin...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.展开更多
The dilepton invariant mass spectra and integrated branching ratios of the single and double Dalitz decays P→l^+l^-γ and P→l^+l^-l^+l^-(P=π^0,η,η';l=e or μ) are predicted by means of a data-driven approac...The dilepton invariant mass spectra and integrated branching ratios of the single and double Dalitz decays P→l^+l^-γ and P→l^+l^-l^+l^-(P=π^0,η,η';l=e or μ) are predicted by means of a data-driven approach based on the use of rational approximants applied to π^0,η and η' transition form factor experimental data in the space-like region.展开更多
A uniform array of scalar-sensors with intersensor spacings over a large aperture size generally offers enhanced resolution and source localization accuracy,but it may also lead to cyclic ambiguity.By exploiting the p...A uniform array of scalar-sensors with intersensor spacings over a large aperture size generally offers enhanced resolution and source localization accuracy,but it may also lead to cyclic ambiguity.By exploiting the polarization information of impinging waves,an electromagnetic vector-sensor array outperforms the unpolarized scalar-sensor array in resolving this cyclic ambiguity.However,the electromagnetic vector-sensor array usually consists of cocentered orthogonal loops and dipoles(COLD),which is easily subjected to mutual coupling across these cocentered dipoles/loops.As a result,the source localization performance of the COLD array may substantially degrade rather than being improved.This paper proposes a new source localization method with a non-cocentered orthogonal loop and dipole(NCOLD)array.The NCOLD array contains only one dipole or loop on each array grid,and the intersensor spacings are larger than a half-wavelength.Therefore,unlike the COLD array,these well separated dipoles/loops minimize the mutual coupling effects and extend the spatial aperture as well.With the NCOLD array,the proposed method can effciently exploit the polarization information to offer high localization precision.展开更多
文摘A wide range of industrial metallurgical heating and melting processes are carried out using electrothermal and electromagnetic technologies.The application of electromagnetic processing offers many advantages from technological, ecological and economical point of view.Although the technology level of the electromagnetic heating and melting installations and processes used in the industry today is very high,there are still potentials for improvement and optimization.In this paper recent applications and future development trends for efficient use of electromagnetic processing technologies in metallurgical and non-metallic material processes are described along selected examples in the field of heating for melting,forging,joining and solidification.
文摘Pulsed external field, including electric, magnetic, ultrasonic and laser, as aninstantaneous high energy input method with high efficiency and low energyconsumption, have long been known to can modify the microstructure and propertiesof materials. This includes electroplasticity, magnetoplasticity, phase transformations,recrystallization, grain refinement, texture control, inclusion removal.
文摘Introduction Cationic starches are a series of products of which various sorts with different properties and usages can all be produced via cationic reactions by using different types of etherification agents under different conditions. As an additive and strengthening agent,
基金Project supported by the National Natural Science Foundation of China (Grant No. 90716019)
文摘A microwave thruster system that can convert microwave power directly to thrust without a gas propellant is devel-oped. In the system, a cylindrical tapered resonance cavity and a magnetron microwave source are used respectively as the thruster cavity and the energy source to generate the electromagnetic wave. The wave is radiated into and then reflected from the cavity to form a pure standing wave with non-uniform electromagnetic pressure distribution. Consequently, a net electromagnetic thrust exerted on the axis of the thruster cavity appears, which is demonstrated through theoretical calcula- tion based on the electromagnetic theory. The net electromagnetic thrust is also experimentally measured in the range from 70 mN to 720 mN when the microwave output power is from 80 W to 2500 W.
基金This work has been partially performed under the financial supports from the National Natural Science Foundation of China (Grant No.50204004)the National Fundamental Research Project - new generation steel research project of China (Grant No.G1998061
文摘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.
基金Supported by the FPI scholarship BES-2012-055371(S.G-S)the Secretaria d'Universitats i Recerca del Departament d'Economia i Coneixement de la Generalitat de Catalunya under grant 2014 SGR 1450+3 种基金the Ministerio de Ciencia e Innovación under grant FPA2011-25948,the Ministerio de Economía y Competitividad under grants CICYT-FEDER-FPA 2014-55613-P and SEV-2012-0234the Spanish Consolider-Ingenio 2010 Program CPAN(CSD2007-00042)the European Commission under program FP7-INFRASTRUCTURES-2011-1(283286)Support from the CAS President's International Fellowship Initiative for Young International Scientist(2017PM0031)
文摘The dilepton invariant mass spectra and integrated branching ratios of the single and double Dalitz decays P→l^+l^-γ and P→l^+l^-l^+l^-(P=π^0,η,η';l=e or μ) are predicted by means of a data-driven approach based on the use of rational approximants applied to π^0,η and η' transition form factor experimental data in the space-like region.
基金supported by the Scientifc Research Fund of Zhejiang Provincial Education Department(No.Y201225848)the Scientifc and Technological Innovation Programs of Higher Education Institutions in Shanxi(No.2013124)
文摘A uniform array of scalar-sensors with intersensor spacings over a large aperture size generally offers enhanced resolution and source localization accuracy,but it may also lead to cyclic ambiguity.By exploiting the polarization information of impinging waves,an electromagnetic vector-sensor array outperforms the unpolarized scalar-sensor array in resolving this cyclic ambiguity.However,the electromagnetic vector-sensor array usually consists of cocentered orthogonal loops and dipoles(COLD),which is easily subjected to mutual coupling across these cocentered dipoles/loops.As a result,the source localization performance of the COLD array may substantially degrade rather than being improved.This paper proposes a new source localization method with a non-cocentered orthogonal loop and dipole(NCOLD)array.The NCOLD array contains only one dipole or loop on each array grid,and the intersensor spacings are larger than a half-wavelength.Therefore,unlike the COLD array,these well separated dipoles/loops minimize the mutual coupling effects and extend the spatial aperture as well.With the NCOLD array,the proposed method can effciently exploit the polarization information to offer high localization precision.