The key problems of cold power spinning of Ti-15-3 alloy are studied. Reasonable billet preparation methods are presented to improve crystal structure and avoid crack of billet. Influences of original wall thickness,...The key problems of cold power spinning of Ti-15-3 alloy are studied. Reasonable billet preparation methods are presented to improve crystal structure and avoid crack of billet. Influences of original wall thickness, reduction rate and feed rate on expanding in diameter are analyzed and some methods to prevent expanding in diameter are given.展开更多
In this paper, a successfully studied and developed master - slave muld - microcomputers control system based on PC - BUS for hollow spindle fancy yarn spinning machine, mainly Its overall scheme, software and hardwar...In this paper, a successfully studied and developed master - slave muld - microcomputers control system based on PC - BUS for hollow spindle fancy yarn spinning machine, mainly Its overall scheme, software and hardware construction, is introduced. Spinning experiments show that the system achieves satisfactory result. This system can solve the diftkultles of mechatronical fusion between domestic hollow splndk fancy yarn spuming muchine and its microcomputer control technology.展开更多
We study theoretically Josephson effect in a planar ballistic junction between two triplet superconductors with pwave orbital symmetries and separated by a two-dimensional(2D)semiconductor channel with strong Rashba s...We study theoretically Josephson effect in a planar ballistic junction between two triplet superconductors with pwave orbital symmetries and separated by a two-dimensional(2D)semiconductor channel with strong Rashba spin–orbit coupling.In triplet superconductors,three types of orbital symmetries are considered.We use Bogoliubov–de Gennes formalism to describe quasiparticle propagations through the junction and the supercurrents are calculated in terms of Andreev reflection coefficients.The features of the variation of the supercurrents with the change of the strength of Rashba spin–orbit coupling are investigated in some detail.It is found that for the three types of orbital symmetries considered,both the magnitudes of supercurrent and the current-phase relations can be manipulated effectively by tuning the strength of Rashba spin–orbit coupling.The interplay of Rashba spin–orbit coupling and Zeeman magnetic field on supercurrent is also investigated in some detail.展开更多
The spin superconductor state is the spin-polarized triplet exciton condensate,which can be viewed as a counterpart of the charge superconductor state.As an analogy of the charge Josephson effect,the spin Josephson ef...The spin superconductor state is the spin-polarized triplet exciton condensate,which can be viewed as a counterpart of the charge superconductor state.As an analogy of the charge Josephson effect,the spin Josephson effect can be generated in the spin superconductor/normal metal/spin superconductor junctions.Here we study the spin supercurrent in the Josephson junctions consisting of two spin superconductors with noncollinear spin polarizations.For the Josephson junctions with out-of-plane spin polarizations,the possibleπ-state spin supercurrent appears due to the Fermi momentum-splitting Andreev-like reflections at the normal metal/spin superconductor interfaces.For the Josephson junctions with in-plane spin polarizations,the anomalous spin supercurrent appears and is driven by the misorientation angle of the in-plane polarizations.The symmetry analysis shows that the appearance of the anomalous spin Josephson current is possible when the combined symmetry of the spin rotation and the time reversal is broken.展开更多
This article presents illustrations of an extended model of the electron to visualize how it spins and radiates in the external magnetic field. A time-varying magnetic field B produces a rotational induced electric fi...This article presents illustrations of an extended model of the electron to visualize how it spins and radiates in the external magnetic field. A time-varying magnetic field B produces a rotational induced electric field E which rotates (spins) the electron about its axis. In time-constant magnetic field: the electron radiates the cyclotron radiation. In time-varying magnetic field: synchrotron radiation is generated. The couplings between spin, acceleration and radiation will be discussed.展开更多
The primariy application of rare - earth spin finishes on PET/PA composite super - fine denier fiber has been studied in this paper. It results in the improvement of fi-ber’s properties, such as increased whiteness, ...The primariy application of rare - earth spin finishes on PET/PA composite super - fine denier fiber has been studied in this paper. It results in the improvement of fi-ber’s properties, such as increased whiteness, brightness and brilliance, effective and uniform spliting of compos-ite fiber into super - fine denier fiber and enhanced dye-ing effect.展开更多
The spinning solar sail of large scale has been well developed in recent years. Such a solar sail can be considered as a rigid-flexible multibody system mainly composed of a spinning central rigid hub, a number of fle...The spinning solar sail of large scale has been well developed in recent years. Such a solar sail can be considered as a rigid-flexible multibody system mainly composed of a spinning central rigid hub, a number of flexible thin tethers, sail membranes, and tip masses. A simplified interplanetary kite-craft accelerated by radiation of the Sun （IKAROS） model is established in this study by using the absolute-coordinate-based （ACB） method that combines the natural coordinate formulation （NCF） describing the central rigid hub and the absolute nodal coordinate formulation （ANCF） describing flexible parts. The initial configuration of the system in the second-stage deployment is determined through both dynamic and static analyses. The huge set of stiff equations of system dynamics is solved by using the generalized-alpha method, and thus the deployment dynamics of the system can be well understood.展开更多
Using the membrane model based on the brick-wall model, we calculate the free energy and entropy of dilatonic black hole due to arbitrary spin fields. The result shows that the entropy of scalar field and the entropy ...Using the membrane model based on the brick-wall model, we calculate the free energy and entropy of dilatonic black hole due to arbitrary spin fields. The result shows that the entropy of scalar field and the entropy of Fermionic field have similar formulas. There is only a numerical coefficient between them.展开更多
ZnSe∶Mn nanocrystals were grown by chemical vapour transport method using the matrix of SiO2 aerogels. The cubic structure of the nanocrystals was confirmed by powder X-ray diffraction (XRD) and electron diffraction ...ZnSe∶Mn nanocrystals were grown by chemical vapour transport method using the matrix of SiO2 aerogels. The cubic structure of the nanocrystals was confirmed by powder X-ray diffraction (XRD) and electron diffraction (ED) studies. The size of the crystals was observed using transmission electron microscope (TEM). The oxidation state of Mn in ZnSe nanocrystal was found using electron spin resonance (ESR) spectrum. The room temperature luminescence measurements show the peaks corresponding to both bandgap of the material and Mn in ZnSe.展开更多
La 0.5- x Y x Ba 0.5 CoO 3 polycrystals were prepared by solid state reaction. The substituting effects of Y for La on the magnetic and transport properties of the materials were studied systematically...La 0.5- x Y x Ba 0.5 CoO 3 polycrystals were prepared by solid state reaction. The substituting effects of Y for La on the magnetic and transport properties of the materials were studied systematically. The results indicate that substitution of Y induces two effects. Firstly, the charge transfer from Y to 3d orbital of Co happens. This causes the molecular magnetic moment to decrease. Secondly, the antiferromagnetic exchange interaction of Co ions appears. When the content of Y is less than or equal to 30%, the non colinear structure of spins in materials is observed. When the content of Y is greater than 30%, the materials transit from predominant ferromagnetic state to predominant antiferromagnetic one. The conductive mechanism for the materials with different content of Y belongs to the variable range hopping conduction of polarons. The resistivity of materials increases sharply with increasing Y content.展开更多
High spin states of 84Sr were populated through the reaction 70Zn(18O,4n)84Sr at 75 MeV beam energy.Measurement of excitation function,γ-γ coincidences,directional correlation from oriented state (DCO) ratios and γ...High spin states of 84Sr were populated through the reaction 70Zn(18O,4n)84Sr at 75 MeV beam energy.Measurement of excitation function,γ-γ coincidences,directional correlation from oriented state (DCO) ratios and γ-transition intensities were performed using eight anticompton HPGe detectors and one planar HPGe detector.Based on the measured results,a new level scheme of 84Sr was established in which 12 new states and nearly 30 new γ-transitions were identified in the present work.The positive-parity states of the new level scheme were compared with the results from calculations in the framework of the projected shell model (PSM).One negative-parity band was extended to spin Iπ=19-and it can be found that in the high spin states,the γ-transition energies show the nature of signature staggering.The negative-parity band levels are in good agreement with deformed configuration-mixing shell model (DCM) calculations.展开更多
Generation of arbitrarily spin-polarized electron and positron beams has been investigated in the single-shot interaction of high-energy polarized r-photons with an ultraintense asymmetric laser pulse via nonlinear Br...Generation of arbitrarily spin-polarized electron and positron beams has been investigated in the single-shot interaction of high-energy polarized r-photons with an ultraintense asymmetric laser pulse via nonlinear Breit-Wheeler pair production.We develop a fully spin-resolved semi-classical Monte Carlo method to describe the pair creation and polarization.In the considered general setup,there are two sources of the polarization of created pairs:the spin angular momentum transfer from the polarized parent-photons,as well as the asymmetry and polarization of the driving laser field.This allows to develop a highly sensitive tool to control the polarization of created electrons and positrons.Thus,dense GeV lepton beams with average polarization degree up to about 80%,adjustable continuously between the transverse and longitudinal components,can be obtained by our all-optical method with currently achievable laser facilities,which could find an application as injectors of the polarized e^(+)e^(-)collider to search for new physics beyond the Standard Model.展开更多
文摘The key problems of cold power spinning of Ti-15-3 alloy are studied. Reasonable billet preparation methods are presented to improve crystal structure and avoid crack of billet. Influences of original wall thickness, reduction rate and feed rate on expanding in diameter are analyzed and some methods to prevent expanding in diameter are given.
文摘In this paper, a successfully studied and developed master - slave muld - microcomputers control system based on PC - BUS for hollow spindle fancy yarn spinning machine, mainly Its overall scheme, software and hardware construction, is introduced. Spinning experiments show that the system achieves satisfactory result. This system can solve the diftkultles of mechatronical fusion between domestic hollow splndk fancy yarn spuming muchine and its microcomputer control technology.
文摘We study theoretically Josephson effect in a planar ballistic junction between two triplet superconductors with pwave orbital symmetries and separated by a two-dimensional(2D)semiconductor channel with strong Rashba spin–orbit coupling.In triplet superconductors,three types of orbital symmetries are considered.We use Bogoliubov–de Gennes formalism to describe quasiparticle propagations through the junction and the supercurrents are calculated in terms of Andreev reflection coefficients.The features of the variation of the supercurrents with the change of the strength of Rashba spin–orbit coupling are investigated in some detail.It is found that for the three types of orbital symmetries considered,both the magnitudes of supercurrent and the current-phase relations can be manipulated effectively by tuning the strength of Rashba spin–orbit coupling.The interplay of Rashba spin–orbit coupling and Zeeman magnetic field on supercurrent is also investigated in some detail.
基金Project supported by the National Key R&D Program of China(Grant No.2022YFA1403601).
文摘The spin superconductor state is the spin-polarized triplet exciton condensate,which can be viewed as a counterpart of the charge superconductor state.As an analogy of the charge Josephson effect,the spin Josephson effect can be generated in the spin superconductor/normal metal/spin superconductor junctions.Here we study the spin supercurrent in the Josephson junctions consisting of two spin superconductors with noncollinear spin polarizations.For the Josephson junctions with out-of-plane spin polarizations,the possibleπ-state spin supercurrent appears due to the Fermi momentum-splitting Andreev-like reflections at the normal metal/spin superconductor interfaces.For the Josephson junctions with in-plane spin polarizations,the anomalous spin supercurrent appears and is driven by the misorientation angle of the in-plane polarizations.The symmetry analysis shows that the appearance of the anomalous spin Josephson current is possible when the combined symmetry of the spin rotation and the time reversal is broken.
文摘This article presents illustrations of an extended model of the electron to visualize how it spins and radiates in the external magnetic field. A time-varying magnetic field B produces a rotational induced electric field E which rotates (spins) the electron about its axis. In time-constant magnetic field: the electron radiates the cyclotron radiation. In time-varying magnetic field: synchrotron radiation is generated. The couplings between spin, acceleration and radiation will be discussed.
文摘The primariy application of rare - earth spin finishes on PET/PA composite super - fine denier fiber has been studied in this paper. It results in the improvement of fi-ber’s properties, such as increased whiteness, brightness and brilliance, effective and uniform spliting of compos-ite fiber into super - fine denier fiber and enhanced dye-ing effect.
基金supported by the National Natural Science Foundation of China (11221202 and 51075032)Excellent Young Scholar Research Fund from Beijing Institute of Technology
文摘The spinning solar sail of large scale has been well developed in recent years. Such a solar sail can be considered as a rigid-flexible multibody system mainly composed of a spinning central rigid hub, a number of flexible thin tethers, sail membranes, and tip masses. A simplified interplanetary kite-craft accelerated by radiation of the Sun （IKAROS） model is established in this study by using the absolute-coordinate-based （ACB） method that combines the natural coordinate formulation （NCF） describing the central rigid hub and the absolute nodal coordinate formulation （ANCF） describing flexible parts. The initial configuration of the system in the second-stage deployment is determined through both dynamic and static analyses. The huge set of stiff equations of system dynamics is solved by using the generalized-alpha method, and thus the deployment dynamics of the system can be well understood.
基金the National Natural Science Foundation of China(Grant No.19873013 and No.10073006)
文摘Using the membrane model based on the brick-wall model, we calculate the free energy and entropy of dilatonic black hole due to arbitrary spin fields. The result shows that the entropy of scalar field and the entropy of Fermionic field have similar formulas. There is only a numerical coefficient between them.
文摘ZnSe∶Mn nanocrystals were grown by chemical vapour transport method using the matrix of SiO2 aerogels. The cubic structure of the nanocrystals was confirmed by powder X-ray diffraction (XRD) and electron diffraction (ED) studies. The size of the crystals was observed using transmission electron microscope (TEM). The oxidation state of Mn in ZnSe nanocrystal was found using electron spin resonance (ESR) spectrum. The room temperature luminescence measurements show the peaks corresponding to both bandgap of the material and Mn in ZnSe.
文摘La 0.5- x Y x Ba 0.5 CoO 3 polycrystals were prepared by solid state reaction. The substituting effects of Y for La on the magnetic and transport properties of the materials were studied systematically. The results indicate that substitution of Y induces two effects. Firstly, the charge transfer from Y to 3d orbital of Co happens. This causes the molecular magnetic moment to decrease. Secondly, the antiferromagnetic exchange interaction of Co ions appears. When the content of Y is less than or equal to 30%, the non colinear structure of spins in materials is observed. When the content of Y is greater than 30%, the materials transit from predominant ferromagnetic state to predominant antiferromagnetic one. The conductive mechanism for the materials with different content of Y belongs to the variable range hopping conduction of polarons. The resistivity of materials increases sharply with increasing Y content.
基金supported by the Major State Basic Research Development Program in China (Grant No. 2007CB815003)the National Natural Science Foundation of China (Grant Nos. 11065001, 10547140, 10525520,60476043,10675170,10475002 and 10775064)+4 种基金the U.S. National Science Foundation (Grant No. 0500291)the Southeastern Universities Research Association,the Natural Science Foundation of Jiangxi Province (Grant Nos. 0612003 and 2007GZW0476)the LSU - LNNU Joint Research Program (Grant No. 9961)the Foundation of the Education Department of Jiangxi Province (Grant No. [2007]235)the Liaoning Education Department Fund (Grant No. 20060464)
文摘High spin states of 84Sr were populated through the reaction 70Zn(18O,4n)84Sr at 75 MeV beam energy.Measurement of excitation function,γ-γ coincidences,directional correlation from oriented state (DCO) ratios and γ-transition intensities were performed using eight anticompton HPGe detectors and one planar HPGe detector.Based on the measured results,a new level scheme of 84Sr was established in which 12 new states and nearly 30 new γ-transitions were identified in the present work.The positive-parity states of the new level scheme were compared with the results from calculations in the framework of the projected shell model (PSM).One negative-parity band was extended to spin Iπ=19-and it can be found that in the high spin states,the γ-transition energies show the nature of signature staggering.The negative-parity band levels are in good agreement with deformed configuration-mixing shell model (DCM) calculations.
基金supported by the National Natural Science Foundation of China(Grants No.12022506,11874295,11875219 and 11905169)the National Key R&D Program of China(Grant No.2019YFA0404900)the Open Fund of the State Key Laboratory of High Field Laser Physics(Shanghai Institute of Optics and Fine Mechanics)and the foundation of science and technology on plasma physics laboratory(No.JCKYS2021212008)。
文摘Generation of arbitrarily spin-polarized electron and positron beams has been investigated in the single-shot interaction of high-energy polarized r-photons with an ultraintense asymmetric laser pulse via nonlinear Breit-Wheeler pair production.We develop a fully spin-resolved semi-classical Monte Carlo method to describe the pair creation and polarization.In the considered general setup,there are two sources of the polarization of created pairs:the spin angular momentum transfer from the polarized parent-photons,as well as the asymmetry and polarization of the driving laser field.This allows to develop a highly sensitive tool to control the polarization of created electrons and positrons.Thus,dense GeV lepton beams with average polarization degree up to about 80%,adjustable continuously between the transverse and longitudinal components,can be obtained by our all-optical method with currently achievable laser facilities,which could find an application as injectors of the polarized e^(+)e^(-)collider to search for new physics beyond the Standard Model.
