Nonlinear vortex gyrotropic motion in a three-nanocontacts system is investigated by micromagnetic slmulations and analytical calculations. Three out-of-plane spin-polarized currents are injected into a nanodisk throu...Nonlinear vortex gyrotropic motion in a three-nanocontacts system is investigated by micromagnetic slmulations and analytical calculations. Three out-of-plane spin-polarized currents are injected into a nanodisk through a centered nanocontact and two off-centered nanocontacts, respectively. For current combination （ipl, ip0, ip2） = （-1,1, -1）, the trajectory of the vortex core is a peanut-like orbit, but it is an elliptical orbit for （ip1, ip0, ip2） = （1, 1, -1）. Moreover, the gyrotropic frequency displays peaks for both current combinations. Analytical calculations based on the Thiele equation show that the changes of frequency can be ascribed mainly to the forces generated by the Oersted field accompanying the currents. We also demonstrate a dependence of eigenfrequency shifts on the direction and distance of the applied currents.展开更多
The dynamic properties of interacting vortex-antivortex pairs in thin film are studied by analytical calculations. An- alytical expressions for the magnetization vector distribution of vortex-antivortex pairs and the ...The dynamic properties of interacting vortex-antivortex pairs in thin film are studied by analytical calculations. An- alytical expressions for the magnetization vector distribution of vortex-antivortex pairs and the trivortex states are given. The magnetic states of the vortices are treated as having rigid structures, i.e., the vortex maintains its spin distribution when moving. The trajectories of the vortex cores are calculated by the Thiele＇s equation. It is found that the vortex-antivortex pair rotates around each other when they have opposite polarities, however, vortex and antivortex cores move along straight lines when they have the same polarity. The frequency of the rotation decreases with increasing the distance between the two cores of vortex-antivortex pair, and it has a lower value when a third vortex is introduced.展开更多
In this paper, a three dimensional matrix valued rational interpolant (TGMRI) is first constructed by making use of the generalized inverse of matrices. The interpolants are of the Thiele type branched continued fra...In this paper, a three dimensional matrix valued rational interpolant (TGMRI) is first constructed by making use of the generalized inverse of matrices. The interpolants are of the Thiele type branched continued fraction form, with matrix numerator and scalar denominator. Some properties of TGMRI are given. An efficient recursive algorithm is proposed. The results in the paper can be extend to n variable.展开更多
Previous work on the optimal activity distribution in catalyst pellets for the nonisothermal A→B reactions is extended to the nonisothermal two-component reactions with the kinetics r=kc<sub>A</sub><su...Previous work on the optimal activity distribution in catalyst pellets for the nonisothermal A→B reactions is extended to the nonisothermal two-component reactions with the kinetics r=kc<sub>A</sub><sup>m<sub>1</sub></sup>c<sub>B</sub><sup>m<sub>2</sub></sup>/（1+K<sub>A</sub>c<sub>A</sub>+K<sub>B</sub>c<sub>B</sub>）<sup>a</sup> and some concepts are generalized. It is shown that the optimal activity distribution is also a Dirac delta function. The optimal location depends on nonisothermal effect parameter βγ, concentration sensitivity parameter π and Thiele modulus φ. A criterion is derived to evaluate the optimal location whether within the pellet or at the external surface. The influences of both the increase of the active layer thickness and the deviation of the active layer location from the optimal location are analysed. The effectiveness factors of pellets are more sensitive to the location than to the thickness.展开更多
HEAR Vienna Philharmonic Classical Music In the world of symphonic and chamber music,the renowned Vienna Philharmonic is the among the best in the business.Under the baton of maestro Andres Orozco-Estrada,the orchestr...HEAR Vienna Philharmonic Classical Music In the world of symphonic and chamber music,the renowned Vienna Philharmonic is the among the best in the business.Under the baton of maestro Andres Orozco-Estrada,the orchestra visited Guangzhou in 2017 for the first time,and are slated to return this October for two performances.On October 24,the celebrated orchestra will be collaborating with Chinese pianist Wang Yujia,who Is a resident musician at New York's Carnegie Hall,as well as well-known German conductor Christian Thielemann the following day.展开更多
The skyrmion Hall effect is theoretically studied in the chiral ferromagnetic film with spatially modulated Dzyaloshinskii-Moriya interaction.Three cases including linear,sinusoidal,and periodic rectangular modulation...The skyrmion Hall effect is theoretically studied in the chiral ferromagnetic film with spatially modulated Dzyaloshinskii-Moriya interaction.Three cases including linear,sinusoidal,and periodic rectangular modulations have been considered,where the increase,decrease,and the periodic modification of the size and velocity of the skyrmion have been observed in the microscopic simulations.These phenomena are well explained by the Thiele equation,where an effective force on the skyrmion is induced by the inhomogeneous Dzyaloshinskii Moriya interaction.The results here suggest that tlic skyrmion Hall effect can be manipulated by artificially timing the DzvaloshinskiiMoriya interaction in chiral ferromagnetic film with material engineering methods,which will be useful to design skyrmion-based spintronics devices.展开更多
目的图像修复在图像处理中起着举足轻重的地位,针对目前大部分图像修补算法在修复划痕时存在纹理修复不够突出的缺陷,提出了两种基于连分式插值的修补算法,可以较好保持图像纹理的特性。方法该算法基于连分式插值理论,采用图像破损点周...目的图像修复在图像处理中起着举足轻重的地位,针对目前大部分图像修补算法在修复划痕时存在纹理修复不够突出的缺陷,提出了两种基于连分式插值的修补算法,可以较好保持图像纹理的特性。方法该算法基于连分式插值理论,采用图像破损点周围像素信息来插值出破损点的像素值。根据插值函数和插值窗口的不同,提出了两种插值方法,即Thiele型修补算法与Newton-Thiele型修补算法,解决不同纹理类型图像的划痕修补问题,并对插值过程中出现的奇异点问题和平移问题提出了行之有效的解决办法。结果对大量的划痕图像进行实验测试,并通过主观评价和客观评价进行评估。客观评价包括峰值信噪比(PSNR)和运行时间的比较。相对于目前流行的一些修补方法来说,本文算法有更好的视觉效果,更高的峰值信噪比和更短的运行时间,峰值信噪比为44.79 d B,运行时间为0.53 s。结论 Thiele型修补算法更加擅长处理纹理垂直于划痕的图像,而Newton-Thiele型修补算法适用于复杂纹理的图像。展开更多
基金Project supported by the National Natural Science Foundation of China(Grant No.11404053)the Fundamental Research Funds for the Central Universities of Ministry of Education of China(Grant No.n130405011)
文摘Nonlinear vortex gyrotropic motion in a three-nanocontacts system is investigated by micromagnetic slmulations and analytical calculations. Three out-of-plane spin-polarized currents are injected into a nanodisk through a centered nanocontact and two off-centered nanocontacts, respectively. For current combination （ipl, ip0, ip2） = （-1,1, -1）, the trajectory of the vortex core is a peanut-like orbit, but it is an elliptical orbit for （ip1, ip0, ip2） = （1, 1, -1）. Moreover, the gyrotropic frequency displays peaks for both current combinations. Analytical calculations based on the Thiele equation show that the changes of frequency can be ascribed mainly to the forces generated by the Oersted field accompanying the currents. We also demonstrate a dependence of eigenfrequency shifts on the direction and distance of the applied currents.
基金Project supported by the National Natural Science Foundation of China(Grant No.11204026)the Fundamental Research Funds for Central Universities of the Ministry of Education of China(Grant No.n130405011)
文摘The dynamic properties of interacting vortex-antivortex pairs in thin film are studied by analytical calculations. An- alytical expressions for the magnetization vector distribution of vortex-antivortex pairs and the trivortex states are given. The magnetic states of the vortices are treated as having rigid structures, i.e., the vortex maintains its spin distribution when moving. The trajectories of the vortex cores are calculated by the Thiele＇s equation. It is found that the vortex-antivortex pair rotates around each other when they have opposite polarities, however, vortex and antivortex cores move along straight lines when they have the same polarity. The frequency of the rotation decreases with increasing the distance between the two cores of vortex-antivortex pair, and it has a lower value when a third vortex is introduced.
文摘In this paper, a three dimensional matrix valued rational interpolant (TGMRI) is first constructed by making use of the generalized inverse of matrices. The interpolants are of the Thiele type branched continued fraction form, with matrix numerator and scalar denominator. Some properties of TGMRI are given. An efficient recursive algorithm is proposed. The results in the paper can be extend to n variable.
文摘Previous work on the optimal activity distribution in catalyst pellets for the nonisothermal A→B reactions is extended to the nonisothermal two-component reactions with the kinetics r=kc<sub>A</sub><sup>m<sub>1</sub></sup>c<sub>B</sub><sup>m<sub>2</sub></sup>/（1+K<sub>A</sub>c<sub>A</sub>+K<sub>B</sub>c<sub>B</sub>）<sup>a</sup> and some concepts are generalized. It is shown that the optimal activity distribution is also a Dirac delta function. The optimal location depends on nonisothermal effect parameter βγ, concentration sensitivity parameter π and Thiele modulus φ. A criterion is derived to evaluate the optimal location whether within the pellet or at the external surface. The influences of both the increase of the active layer thickness and the deviation of the active layer location from the optimal location are analysed. The effectiveness factors of pellets are more sensitive to the location than to the thickness.
文摘HEAR Vienna Philharmonic Classical Music In the world of symphonic and chamber music,the renowned Vienna Philharmonic is the among the best in the business.Under the baton of maestro Andres Orozco-Estrada,the orchestra visited Guangzhou in 2017 for the first time,and are slated to return this October for two performances.On October 24,the celebrated orchestra will be collaborating with Chinese pianist Wang Yujia,who Is a resident musician at New York's Carnegie Hall,as well as well-known German conductor Christian Thielemann the following day.
文摘The skyrmion Hall effect is theoretically studied in the chiral ferromagnetic film with spatially modulated Dzyaloshinskii-Moriya interaction.Three cases including linear,sinusoidal,and periodic rectangular modulations have been considered,where the increase,decrease,and the periodic modification of the size and velocity of the skyrmion have been observed in the microscopic simulations.These phenomena are well explained by the Thiele equation,where an effective force on the skyrmion is induced by the inhomogeneous Dzyaloshinskii Moriya interaction.The results here suggest that tlic skyrmion Hall effect can be manipulated by artificially timing the DzvaloshinskiiMoriya interaction in chiral ferromagnetic film with material engineering methods,which will be useful to design skyrmion-based spintronics devices.
文摘目的图像修复在图像处理中起着举足轻重的地位,针对目前大部分图像修补算法在修复划痕时存在纹理修复不够突出的缺陷,提出了两种基于连分式插值的修补算法,可以较好保持图像纹理的特性。方法该算法基于连分式插值理论,采用图像破损点周围像素信息来插值出破损点的像素值。根据插值函数和插值窗口的不同,提出了两种插值方法,即Thiele型修补算法与Newton-Thiele型修补算法,解决不同纹理类型图像的划痕修补问题,并对插值过程中出现的奇异点问题和平移问题提出了行之有效的解决办法。结果对大量的划痕图像进行实验测试,并通过主观评价和客观评价进行评估。客观评价包括峰值信噪比(PSNR)和运行时间的比较。相对于目前流行的一些修补方法来说,本文算法有更好的视觉效果,更高的峰值信噪比和更短的运行时间,峰值信噪比为44.79 d B,运行时间为0.53 s。结论 Thiele型修补算法更加擅长处理纹理垂直于划痕的图像,而Newton-Thiele型修补算法适用于复杂纹理的图像。
