An external electric or magnetic field can transfer high-intensity energy directly to the electronic scale of materials,and change the spin,energy level arrangement and trajectory of electrons.These changes produce tr...An external electric or magnetic field can transfer high-intensity energy directly to the electronic scale of materials,and change the spin,energy level arrangement and trajectory of electrons.These changes produce tremendous and profound impacts on the microstructure and mechanical properties of metal materials,which may be impos-sible with traditional technologies.This paper reviews the effects of electric or magnetic field on the microstruc-tures of solid metals including phase transformation,precipitation,recrystallization,dislocations and so on.Based on the existing research results,the mechanisms of these effects have been discussed.Additionally,some typical applications of electric and magnetic treatments on solid metals have been described and the challenges in this field have also been discussed.展开更多
Aim: To explore what is the relationship of the types of post-stroke aphasia with sex, age and stroke types. Methods: Retrospective analysis was administrated on data of 421 patients with acute stroke. Western battery...Aim: To explore what is the relationship of the types of post-stroke aphasia with sex, age and stroke types. Methods: Retrospective analysis was administrated on data of 421 patients with acute stroke. Western battery aphasia was used to measure aphasiac type and aphasia quotient (AQ) score. The patients were divided into three age groups: young, middle-aged and elderly. The stroke types were classified into cerebral infraction (CI) and intracerebral hemorrhage (ICH). Results: All subjects were right-handed, which males and females accounted for 69.60% and 30.40%, respectively. There were 116 cases of Broca’s aphasia (85 males), 35 cases of Wernicke’s aphasia (20 males), 15 cases of conductive aphasia (10 males), 63 cases of transcortical motor aphasia (50 males), 11 cases of transcortical sensory aphasia (8 males), 27 cases of transcortical combined aphasia (13 males), 73 cases of anomic aphasia (47 males) and 81 cases of global aphasia (60 males). Male patients (69.60%) have a significantly higher morbidity of aphasia than that of females (30.40%) after stroke (χ2 = 11.57, P = 0.003), especially those under 65 years old (73.38%). For people 65 years and older, the morbidity of female (42.97%) tends to increase with age. Sex has no significant influence on the types of aphasia (χ2 = 13.84, P = 0.054). Broca’s aphasia is the most common type inboth male and female (29.01%, 24.22%, respectively). The distribution of aphasic types has no obvious difference among three age groups (χ2 = 14.94, P= 0.382). Aphasia induced by CI (306 cases) is more common than that by ICH (115 cases), but there was no difference in distribution of types of aphasia (χ2 = 13.23, P = 0.067). Conclusions: Male patients have a significantly higher level of morbidity of aphasia than females after stroke and a lower average age of onset than females. Broca’s aphasia is the most common one in both male and female. Broca’s aphasia, global and anomic aphasia are the most common aphasic types in both CI and ICH patients, except the female with ICH.展开更多
Residual stress reduction in low alloy steel by a low frequency alternating magnetic treatment and its mechanism were investigated. Experimental results revealed that average stress reductions of 20%-24% were obtained...Residual stress reduction in low alloy steel by a low frequency alternating magnetic treatment and its mechanism were investigated. Experimental results revealed that average stress reductions of 20%-24% were obtained in the welded samples. Moreover, compared with the zones with lower initial stress levels, more remarkable stress reductions were obtained in the stress concentration zones. The microstructures and magnetic domains were observed by scanning electron microscopy (SEM) and atomic force microscopy (AFM). Based on the analysis of the microstructure and magnetic domain changes, the mechanism of stress reduction by the magnetic treatment has been concluded: (1) the magneto-plastic deformations mainly due to the more uniform redistribution of dislocations are the fundamental cause of stress relaxation; and (2) surface topography is also proved to affect the magnetic treatment results to some degree by influencing magnetic domains.展开更多
The authors examine the quantization commutes with reduction phenomenon for Hamiltonian actions of compact Lie groups on closed symplectic manifolds from the point of view of topological K-theory and K-homology. They ...The authors examine the quantization commutes with reduction phenomenon for Hamiltonian actions of compact Lie groups on closed symplectic manifolds from the point of view of topological K-theory and K-homology. They develop the machinery of K-theory wrong-way maps in the context of orbifolds and use it to relate the quantization commutes with reduction phenomenon to Bott periodicity and the K-theory formulation of the Weyl character formula.展开更多
基金Supported by National Key Research and Development Program of China(Grant No.2020YFA0714900)National Natural Science Foundation of China(Grant Nos.51975440,51975441)+1 种基金the 111 Project(Grant No.B17034)Innovative Research Team Development Program of Ministry of Education of China(Grant No.IRT17R83).
文摘An external electric or magnetic field can transfer high-intensity energy directly to the electronic scale of materials,and change the spin,energy level arrangement and trajectory of electrons.These changes produce tremendous and profound impacts on the microstructure and mechanical properties of metal materials,which may be impos-sible with traditional technologies.This paper reviews the effects of electric or magnetic field on the microstruc-tures of solid metals including phase transformation,precipitation,recrystallization,dislocations and so on.Based on the existing research results,the mechanisms of these effects have been discussed.Additionally,some typical applications of electric and magnetic treatments on solid metals have been described and the challenges in this field have also been discussed.
文摘Aim: To explore what is the relationship of the types of post-stroke aphasia with sex, age and stroke types. Methods: Retrospective analysis was administrated on data of 421 patients with acute stroke. Western battery aphasia was used to measure aphasiac type and aphasia quotient (AQ) score. The patients were divided into three age groups: young, middle-aged and elderly. The stroke types were classified into cerebral infraction (CI) and intracerebral hemorrhage (ICH). Results: All subjects were right-handed, which males and females accounted for 69.60% and 30.40%, respectively. There were 116 cases of Broca’s aphasia (85 males), 35 cases of Wernicke’s aphasia (20 males), 15 cases of conductive aphasia (10 males), 63 cases of transcortical motor aphasia (50 males), 11 cases of transcortical sensory aphasia (8 males), 27 cases of transcortical combined aphasia (13 males), 73 cases of anomic aphasia (47 males) and 81 cases of global aphasia (60 males). Male patients (69.60%) have a significantly higher morbidity of aphasia than that of females (30.40%) after stroke (χ2 = 11.57, P = 0.003), especially those under 65 years old (73.38%). For people 65 years and older, the morbidity of female (42.97%) tends to increase with age. Sex has no significant influence on the types of aphasia (χ2 = 13.84, P = 0.054). Broca’s aphasia is the most common type inboth male and female (29.01%, 24.22%, respectively). The distribution of aphasic types has no obvious difference among three age groups (χ2 = 14.94, P= 0.382). Aphasia induced by CI (306 cases) is more common than that by ICH (115 cases), but there was no difference in distribution of types of aphasia (χ2 = 13.23, P = 0.067). Conclusions: Male patients have a significantly higher level of morbidity of aphasia than females after stroke and a lower average age of onset than females. Broca’s aphasia is the most common one in both male and female. Broca’s aphasia, global and anomic aphasia are the most common aphasic types in both CI and ICH patients, except the female with ICH.
基金funded by the Teaching and Research Award Program for Outstanding Young Teachers in Higher Education Institutions of Ministry of Education, China (No.[2002]383)the Science and Technology Planning Project of Wuhan City, China (No.20067003111-05)
文摘Residual stress reduction in low alloy steel by a low frequency alternating magnetic treatment and its mechanism were investigated. Experimental results revealed that average stress reductions of 20%-24% were obtained in the welded samples. Moreover, compared with the zones with lower initial stress levels, more remarkable stress reductions were obtained in the stress concentration zones. The microstructures and magnetic domains were observed by scanning electron microscopy (SEM) and atomic force microscopy (AFM). Based on the analysis of the microstructure and magnetic domain changes, the mechanism of stress reduction by the magnetic treatment has been concluded: (1) the magneto-plastic deformations mainly due to the more uniform redistribution of dislocations are the fundamental cause of stress relaxation; and (2) surface topography is also proved to affect the magnetic treatment results to some degree by influencing magnetic domains.
文摘The authors examine the quantization commutes with reduction phenomenon for Hamiltonian actions of compact Lie groups on closed symplectic manifolds from the point of view of topological K-theory and K-homology. They develop the machinery of K-theory wrong-way maps in the context of orbifolds and use it to relate the quantization commutes with reduction phenomenon to Bott periodicity and the K-theory formulation of the Weyl character formula.