Researchers are investigating the possibility of developing Eye drops that will dissolve protein clumps that cause cataracts,but this study is in its early stages.Our aim in this article is to think about geometric-ma...Researchers are investigating the possibility of developing Eye drops that will dissolve protein clumps that cause cataracts,but this study is in its early stages.Our aim in this article is to think about geometric-mathematical tools,that compare such Eye drops to a vector flux through a closed curved surface as an Eye lens,with the help of Gauss’s Theorem.展开更多
IN this letter we discuss the necessary and sufficient condition of C^0 flows on closed surfaces with isolated singular points having the pseudo-orbit tracing property. According to ref. [1], on a closed surface, ever...IN this letter we discuss the necessary and sufficient condition of C^0 flows on closed surfaces with isolated singular points having the pseudo-orbit tracing property. According to ref. [1], on a closed surface, every minimal set of a C^r(r≥2) flow is trivial, but it is possible for a C^0 flow to contain non-trivial minimal sets. Thus C^0 flows on closed surfaces are more complicated than C^r(r≥2) flows.展开更多
Electron orbits under the external vertical field （Bv） and the self poloidal field of the toroidal plasma current in a toroidal geometry are investigated by using analytic model fields in order to search for the con...Electron orbits under the external vertical field （Bv） and the self poloidal field of the toroidal plasma current in a toroidal geometry are investigated by using analytic model fields in order to search for the conditions of occurence of appropriate confinement asymmetry of fast electrons along the field lines. This asymmetry efficiently and quickly generates a toroidal current, which may close the field lines in ECH-started plasmas. It is analytically shown that the characteristics of confinement asymmetry depend on the product of the major radius and the strength of the external vertical field. The results suggest that in large devices By should be lowered and also some artificial means to speed up the pitch angle scattering for the fast electrons at a higher energy range are beneficial to generate the toroidal current in order to close the filed展开更多
Multiresolution modeling is becoming a powerful tool for fast display, and geometric data compression and transmission of complex shapes. Most of the existing literatures investigating the multiresolution for B-spline...Multiresolution modeling is becoming a powerful tool for fast display, and geometric data compression and transmission of complex shapes. Most of the existing literatures investigating the multiresolution for B-spline curves and surfaces are concentrated on open ones. In this paper, we focus on the multiresolution representations and editing of closed B-spline curves and surfaces using wavelets. A repetition approach is adopted for the multiresolution analysis of closed B-spline curves and surfaces. Since the closed curve or surface itself is periodic, it can overcome the drawback brought by the repetition method, i.e. introducing the discontinuities at the boundaries. Based on the models at different multiresolution levels, the multiresolution editing methods of closed curves and surfaces are introduced. Users can edit the overall shape of a closed one while preserving its details, or change its details without affecting its overall shape.展开更多
In this paper we give a new and elementary proof to the following fact:each closed orientable surface of positive genus admits a both chaotic and expansive homeomorphism.Further more,we show that the homeomorphisms gi...In this paper we give a new and elementary proof to the following fact:each closed orientable surface of positive genus admits a both chaotic and expansive homeomorphism.Further more,we show that the homeomorphisms given are also weakly mixing.展开更多
文摘Researchers are investigating the possibility of developing Eye drops that will dissolve protein clumps that cause cataracts,but this study is in its early stages.Our aim in this article is to think about geometric-mathematical tools,that compare such Eye drops to a vector flux through a closed curved surface as an Eye lens,with the help of Gauss’s Theorem.
文摘IN this letter we discuss the necessary and sufficient condition of C^0 flows on closed surfaces with isolated singular points having the pseudo-orbit tracing property. According to ref. [1], on a closed surface, every minimal set of a C^r(r≥2) flow is trivial, but it is possible for a C^0 flow to contain non-trivial minimal sets. Thus C^0 flows on closed surfaces are more complicated than C^r(r≥2) flows.
文摘Electron orbits under the external vertical field （Bv） and the self poloidal field of the toroidal plasma current in a toroidal geometry are investigated by using analytic model fields in order to search for the conditions of occurence of appropriate confinement asymmetry of fast electrons along the field lines. This asymmetry efficiently and quickly generates a toroidal current, which may close the field lines in ECH-started plasmas. It is analytically shown that the characteristics of confinement asymmetry depend on the product of the major radius and the strength of the external vertical field. The results suggest that in large devices By should be lowered and also some artificial means to speed up the pitch angle scattering for the fast electrons at a higher energy range are beneficial to generate the toroidal current in order to close the filed
文摘Multiresolution modeling is becoming a powerful tool for fast display, and geometric data compression and transmission of complex shapes. Most of the existing literatures investigating the multiresolution for B-spline curves and surfaces are concentrated on open ones. In this paper, we focus on the multiresolution representations and editing of closed B-spline curves and surfaces using wavelets. A repetition approach is adopted for the multiresolution analysis of closed B-spline curves and surfaces. Since the closed curve or surface itself is periodic, it can overcome the drawback brought by the repetition method, i.e. introducing the discontinuities at the boundaries. Based on the models at different multiresolution levels, the multiresolution editing methods of closed curves and surfaces are introduced. Users can edit the overall shape of a closed one while preserving its details, or change its details without affecting its overall shape.
基金The first author is supported by the Special Foundation of National Prior Basis Research of China(Grant No.G1999075108)the second author is supported by National Natural Science Foundation of China(11171320 and 11431012).
文摘In this paper we give a new and elementary proof to the following fact:each closed orientable surface of positive genus admits a both chaotic and expansive homeomorphism.Further more,we show that the homeomorphisms given are also weakly mixing.
