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对方来球旋转性质对拉弧圈球效果的理论探讨 被引量:1
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作者 唐东阳 徐金陆 曾藕元 《体育研究与教育》 2013年第1期112-114,共3页
通过对拉弧圈球过程的动力学分析,得出:拉对方的下旋来球比拉对方的上旋来球需要更大的切向挥拍速度,且来球下旋越强烈,切向挥拍速度要求越高,才能拉出弧圈球;为达到拉球的最佳效果,拉对方的上旋来球比拉对方的下旋来球所需较长的摩擦时... 通过对拉弧圈球过程的动力学分析,得出:拉对方的下旋来球比拉对方的上旋来球需要更大的切向挥拍速度,且来球下旋越强烈,切向挥拍速度要求越高,才能拉出弧圈球;为达到拉球的最佳效果,拉对方的上旋来球比拉对方的下旋来球所需较长的摩擦时间,且来球上旋越强烈,所需时间越长;拉对方下旋来球比拉对方上旋来球,回球的旋转效果更好,对方来球下旋越强烈,回球旋转也越强;拉对方上旋来球比拉对方下旋来球,回球更容易过网,且对方上旋越强烈,越容易过网,但要防止拉出台。 展开更多
关键词 对方来球 旋转性质 强度 拉弧圈球 效果
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Electronic Transport Properties of Spin-Crossover Magnet Fe(Ⅱ)-N4S2 Complexes
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作者 杜明丽 胡玉洁 +1 位作者 黄静 李群祥 《Chinese Journal of Chemical Physics》 SCIE CAS CSCD 2018年第1期33-38,I0001,共7页
Spin-crossover (SCO) magnets can act as one of the most possible building blocks in molec- ular spintronics due to their magnetic bistability between the high-spin (HS) and low-spin (LS) states. Here, the electr... Spin-crossover (SCO) magnets can act as one of the most possible building blocks in molec- ular spintronics due to their magnetic bistability between the high-spin (HS) and low-spin (LS) states. Here, the electronic structures and transport properties through SCO magnet Fe(II)-N4S2 complexes sandwiched between gold electrodes are explored by performing exten- sive density functional theory calculations combined with non-equilibrium Green's function formalism. The optimized Fe-N and Fe-S distances and predicted magnetic moment of the SCO magnet Fe(II)-N4S2 complexes agree well with the experimental results. The reversed spin transition between the HS and LS states can be realized by visible light irradiation according to the estimated SCO energy barriers. Based on the obtained transport results, we observe nearly perfect spin-filtering effect in this SCO magnet Fe(II)-N4S2 junction with the HS state, and the corresponding current under small bias voltage is mainly contributed by the spin-down electrons, which is obviously larger than that of the LS case. Clearly, these theoretical findings suggest that SCO magnet Fe(II)-N4S2 complexes hold potential applications in molecular spintronies. 展开更多
关键词 Electronic structure Transport property Spin-crossover magnet Spin-filteringeffect
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Systematic Study on Triaxial Superdeformed Bands of Hf Isotopes
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作者 ZHANG Da-Li DING Bin-Gang 《Communications in Theoretical Physics》 SCIE CAS CSCD 2009年第1期126-130,共5页
Properties of the triaxiai superdeformed (TSD) bands of Hf isotopes are investigated systematicaily within the supersymmetry scheme including many-body interactions and a perturbation possessing the SO(5) (or SU... Properties of the triaxiai superdeformed (TSD) bands of Hf isotopes are investigated systematicaily within the supersymmetry scheme including many-body interactions and a perturbation possessing the SO(5) (or SU(5)) symmetry on the rotational symmetry. Quantitatively good results of the γ-ray energies, the dynamical moments of inertia, and the spin of the TSD bands in Hf isotopes are obtained. It shows that this approach is quite powerful in describing the properties of the triaxial superdeformation in Hf isotopes. 展开更多
关键词 triaxial superdeformed bands dynamical moments of inertia Hf isotopes
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A Mass Transfer Model for Devolatilization of Highly Viscous Media in Rotating Packed Bed 被引量:13
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作者 李沃源 毋伟 +3 位作者 邹海魁 初广文 邵磊 陈建峰 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2010年第2期194-201,共8页
A mass transfer model for devolatilization process of highly viscous media in rotating packed bed(RPB) was developed based on penetration theory and mass conservation.Before establishing the model,some mass transfer e... A mass transfer model for devolatilization process of highly viscous media in rotating packed bed(RPB) was developed based on penetration theory and mass conservation.Before establishing the model,some mass transfer experiments of thin film were conducted in a designed diffusion cell including vacuum and feeding system. In this study,acetone was used as the volatile organic compound(VOC) and syrup as the highly viscous media.The thickness of thin film was changed by using different liquid distributor.It was found that bubbling played an important role in the devolatilization.The correlation of diffusion coefficient of acetone in highly viscous dilute solution was proposed.The relative error between predicted and experimental data was within the range of ± 30% for diffusion coefficient of acetone in syrup.A comparison of experimental data of RPB with model indicated that the relative error was within ± 30% for efficiency of acetone removal. 展开更多
关键词 mass transfer highly viscous liquid volatile organic compound diffusion coefficient rotating packed bed
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Characteristics of Fin Baffle Packing Used in Rotating Packed Bed 被引量:23
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作者 栗秀萍 刘有智 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2010年第1期55-60,共6页
For an alcohol/water system and with fin baffle packing,continuous distillation experiments were carried out in a rotating packed bed(RPB)system at atmospheric pressure.The effects of the average high gravity factor(... For an alcohol/water system and with fin baffle packing,continuous distillation experiments were carried out in a rotating packed bed(RPB)system at atmospheric pressure.The effects of the average high gravity factor(β),liquid reflux ratio(R)and feedstock flux(F)on the momentum transfer and mass transfer were investigated. The gas phase pressure drop of RPB increased with the average high gravity factor,liquid reflux ratio and feedstock flux,which was 13.55-64.37 Pa atβof 2.01-51.49,R of 1.0-2.5,and F of 8-24 L·h1for a theoretical tray in the RPB with fin baffle packing.The investigation on the mass transfer in the RPB with different packings showed that the number of transfer units of RPB with a packing also increased with the average high gravity factor,reflux ratio and feedstock flux.It is found that the fin baffle packing(packing III)presents the best mass transfer performance and lowest pressure drop for the height equivalent to a theoretical plate(HETP),which is 6.59-9.84 mm. 展开更多
关键词 CHARACTERISTIC fin baffle packing DISTILLATION rotating packed bed
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Frame Dragging Effect on Properties of Rotating Neutron Stars with Strong Magnetic Field
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作者 GUO Yu-Wu WEN De-Hua HU Jian-Xun 《Communications in Theoretical Physics》 SCIE CAS CSCD 2008年第12期1469-1472,共4页
The general relativistic frame dragging effect on the properties,such as the moments of inertia and the radiiof gyration of fast rotating neutron stars with a uniform strong magnetic field,is calculated accurate to th... The general relativistic frame dragging effect on the properties,such as the moments of inertia and the radiiof gyration of fast rotating neutron stars with a uniform strong magnetic field,is calculated accurate to the first orderin the uniform angular velocity.The results show that compared with the corresponding non-rotating static sphericalsymmetric neutron star with a weaker magnetic field,a fast rotating neutron star(millisecond pulsar)with a strongermagnetic field has a relative smaller moment of inertia and radius of gyration. 展开更多
关键词 rotating neutron star frame dragging effect moment of inertia magnetic field
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Mass transfer characteristics in a rotating packed bed with split packing 被引量:4
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作者 Youzhi Liu Deyin Gu +2 位作者 Chengcheng Xu Guisheng Qi Weizhou Jiao 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2015年第5期868-872,共5页
The rotating packed bed (RPB) with split packing is a novel gas-liquid contactor, which intensifies the mass transfer processes controlled by gas-side resistance. To assess its efficacy, the mass transfer characteri... The rotating packed bed (RPB) with split packing is a novel gas-liquid contactor, which intensifies the mass transfer processes controlled by gas-side resistance. To assess its efficacy, the mass transfer characteristics with adjacent rings in counter-rotation and co-rotation modes in a split packing RPB were studied experimentally. The physical absorption system NH3-H2O was used for characterizing the gas volumetric mass transfer coeffi- cient (kyae) and the effective inteffacial area (ae) was determined by chemical absorption in the CO2-NaOH sys- tem. The variation in kyae and ae with the operating conditions is also investigated. The experimental results indicated that kyae and ae for counter-rotation of the adjacent packing rings in the split packing RPB were higher than those for co-rotation, and both counter-rotation and co-rotation of the split packing RPB were superior over conventional RPBs under the similar ooerating conditions. 展开更多
关键词 Rotating packed bed (RPB) Split packing Mass transfer Physical absorption Chemical absorption
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An edge-preserving algorithm of joint image restoration and volume reconstruction for rotation-scanning 4D echocardiographic images
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作者 GUO Qiang YANG Xin 《Journal of Zhejiang University-Science A(Applied Physics & Engineering)》 SCIE EI CAS CSCD 2006年第6期960-968,共9页
A statistical algorithm for the reconstruction from time sequence echocardiographic images is proposed in this paper. The ability to jointly restore the images and reconstruct the 3D images without blurring the bounda... A statistical algorithm for the reconstruction from time sequence echocardiographic images is proposed in this paper. The ability to jointly restore the images and reconstruct the 3D images without blurring the boundary is the main innovation of this algorithm. First, a Bayesian model based on MAP-MRF is used to reconstruct 3D volume, and extended to deal with the images acquired by rotation scanning method. Then, the spatiotemporal nature of ultrasound images is taken into account for the pa-rameter of energy function, which makes this statistical model anisotropic. Hence not only can this method reconstruct 3D ul-trasound images, but also remove the speckle noise anisotropically. Finally, we illustrate the experiments of our method on the synthetic and medical images and compare it with the isotropic reconstruction method. 展开更多
关键词 ECHOCARDIOGRAPHY Image reconstruction ANISOTROPIC
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Magnetic Properties of Spin-1/2 Ising Superlattice
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作者 LIU Wei-Jie XIN Zi-Hua HU Hong-Liang 《Communications in Theoretical Physics》 SCIE CAS CSCD 2007年第5期955-960,共6页
Using the effective-field theory we studied the magnetic properties of a spin-1/2 Ising supedattice, which consist of three different ferromagnet materials. The magnetic behavior of this superlattice is examined. The ... Using the effective-field theory we studied the magnetic properties of a spin-1/2 Ising supedattice, which consist of three different ferromagnet materials. The magnetic behavior of this superlattice is examined. The critical temperature and the compensation temprature of the system are studied as a function of the exchange interactions between the nearest-neiboring spins across the interface and in the intraface. Temperature dependence of magenetizations is also given. 展开更多
关键词 Ising superlattice effective field theory phase transition compensation point
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Evolution of Spiral Waves in Excitable Systems
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作者 REN Ji-Rong ZHU Tao MO Shu-Fan 《Communications in Theoretical Physics》 SCIE CAS CSCD 2009年第4期621-626,共6页
Spiral waves, whose rotation center can be regarded as a point defect, widely exist in various two-dimensional excitable systems. In this paper, by making use of Duan's topological current theory, we obtain the charg... Spiral waves, whose rotation center can be regarded as a point defect, widely exist in various two-dimensional excitable systems. In this paper, by making use of Duan's topological current theory, we obtain the charge density of spiral waves and the topological inner structure of its topological charge. The evolution of spiral wave is also studied from the topological properties of a two-dimensional vector field. The spiral waves are found generating or annihilating at the limit points and encountering, splitting, or merging at the bifurcation points of the two-dimensional vector field. Some applications of our theory are also discussed. 展开更多
关键词 topological current spiral wave bifurcation theory of spiral wave
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关于劈长的疑问
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《乒乓世界》 2003年第4期53-53,共1页
关键词 乒乓球 劈长 发球技术 防守技术 步法 旋转性质
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Critical Properties of a Generalized Planar Rotator Model
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作者 孙运周 谭艳荣 陈飞明 《Communications in Theoretical Physics》 SCIE CAS CSCD 2012年第5期893-896,共4页
The critical properties of the planar rotator model with chiral Dzyaloshinsky-Moriya interaction are analyzed using a hybrid Monte Carlo method.Simulations on different lattices conform an observation that there is an... The critical properties of the planar rotator model with chiral Dzyaloshinsky-Moriya interaction are analyzed using a hybrid Monte Carlo method.Simulations on different lattices conform an observation that there is an XY-like Berezinskii-Kosterlitz-Thouless (BKT) phase transition in this model.The ground state and some thermodynamics properties are also discussed. 展开更多
关键词 critical property phase transition XY model Monte Carlo method
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Rotational properties of the odd-Z transfermium nucleus ^(255)Lr by a particle-number-conserving method in the cranked shell model
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作者 Yu-Chun Li Xiao-Tao He 《Science China(Physics,Mechanics & Astronomy)》 SCIE EI CAS CSCD 2016年第7期25-32,共8页
Experimentally observed ground state band based on the 1/2-[521] Nilsson state and the first exited band based on the 7/2-[514] Nilsson state of the odd-Z nucleus 255Lr are studied by the cranked shell model (CSM) w... Experimentally observed ground state band based on the 1/2-[521] Nilsson state and the first exited band based on the 7/2-[514] Nilsson state of the odd-Z nucleus 255Lr are studied by the cranked shell model (CSM) with the paring correlations treated by the particle-number-conserving (PNC) method. This is the first time the detailed theoretical investigations are performed on these rotational bands. Both experimental kinematic and dynamic moments of inertia (f^(1) and ,f^(2) versus rotational frequency are reproduced quite well by the PNC-CSM calculations. By comparing the theoretical kinematic moment of inertia f(1) with the experimental ones extracted from different spin assignments, the spin 17/2- →13/2- is assigned to the lowest-lying 196.6(5) keV transition of the 1/2- [521 ] band, and 15/2→11/2- to the 189(1) keV transition of the 7/2- [514] band, respectively. The proton N = 7 major shell is included in the calculations. The intruder of the high-j low→lj15/2 (1/2-[770]) orbital at the high spin leads to band-crossings at hω = 0.20 (hω~=0.25) MeV for the 7/2-[514]ω= -1/2 (ω= +1/2) band, and at hω=0.175 MeV for the 1/2- [521 ] ω= - 1/2 band, respectively. Further investigations show that the band-crossing frequencies are quadrupole deformation dependent. 展开更多
关键词 rotational band spin assignment band-crossing high-j orbital transfermium nuclei
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