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91.
Closely packed dense frequency selective surface 总被引:1,自引:0,他引:1
In order to realize wideband filtering properties of frequency selective surface (FSS), FSS of closely packed elements is presented. The Y loop elements are chosen as the graphics elements. Based on the spectral domain method, the frequency response is analyzed for different incident angles and polarizations. The result of the numerical analysis shows that the dense FSS has wide passband with better independence of angle and polarization. 相似文献
92.
The class of local analyitic Bruck loops (or equivalently K-loops) is strongly related to locally symmetric spaces. In particular, both have Lie triple systems as their tangent algebra. In this paper, we consider the existence and some properties of the Campbell-Hausdorff series of local analytic Bruck loops (K-loops). This formula can be used to determine the local symmetries of the associated symmetric space. 相似文献
93.
Linus Kramer 《Geometriae Dedicata》2002,92(1):145-178
In these notes we describe some buildings related to complex Kac–Moody groups. First we describe the spherical building of SLn() (i.e. the projective geometry PG(n)) and its Veronese representation. Next we recall the construction of the affine building associated to a discrete valuation on the rational function field (z). Then we describe the same building in terms of complex Laurent polynomials, and introduce the Veronese representation, which is an equivariant embedding of the building into an affine Kac–Moody algebra. Next, we introduce topological twin buildings. These buildings can be used for a proof which is a variant of the proof by Quillen and Mitchell, of Bott periodicity which uses only topological geometry. At the end we indicate very briefly that the whole process works also for affine real almost split Kac–Moody groups.Supported by a Heisenberg fellowship by the Deutsche Forschungsgemeinschaft. 相似文献
94.
On the basis of the modified Bloch equations a theory is developed of the light self-diffraction in a thin film of a dense resonant medium with allowance for the dipole-dipole interactions of atoms. It is shown that for certain values of intensity of an external field, there occurs in the film the light-induced first-kind phase transition which causes the emergence of regions (domains) with the high excitation of atoms. The switching effects of the system dense resonant medium + periodically-modulated field under consideration result in a hysteresis behaviour in the dependence of the diffraction efficiency on the adiabatically changing intensity of the external field. The predicted hysteresis offers additional potentialities in the investigation of the dynamics of the first-kind phase transition in dense media and outlook for usage of the film as a switching logical element. 相似文献
96.
XIA Tie-Cheng YU Fa-Jun CHEN Deng-Yuan 《理论物理通讯》2004,42(10)
A new simple loop algebra G M is constructed, which is devoted to establishing an isospectral problem. By making use of Tu scheme, the multi-component C-KdV hierarchy is obtained. Further, an expanding loop algebra FM of the loop algebra G M is presented. Based on FM , the multi-component integrable coupling system of the multi-component C-KdV hierarchy is worked out. The method can be used to other nonlinear evolution equations hierarchy. 相似文献
97.
Fukui Guo Yufeng Zhang Qingyou Yan 《International Journal of Theoretical Physics》2004,43(4):1139-1146
A new simple method for obtaining integrable hierarchies of soliton equations is proposed. First of all, a new loop algebra
is constructed, whose commutation operation is clear as that in loop algebra
. Second, by making use of the Tu scheme, many of integrable hierarchies with multicomponent potential functions can be produced. As a specific application of our method, a multicomponent AKNS hierarchy is obtained. Finally, an expanding loop algebra
of the loop algebra
is constructed. Taking advantage of
above, a type of integrable coupling system of the multicomponent AKNS hierarchy is worked out. 相似文献
98.
It is shown that (1) if a good set has finitely many related components, then they are full, (2) loops correspond one-to-one
to extreme points of a convex set. Some other properties of good sets are discussed. 相似文献
99.
We develop a notion of an n-fold monoidal category and show that it corresponds in a precise way to the notion of an n-fold loop space. Specifically, the group completion of the nerve of such a category is an n-fold loop space, and free n-fold monoidal categories give rise to a finite simplicial operad of the same homotopy type as the classical little cubes operad used to parametrize the higher H-space structure of an n-fold loop space. We also show directly that this operad has the same homotopy type as the n-th Smith filtration of the Barratt-Eccles operad and the n-th filtration of Berger's complete graph operad. Moreover, this operad contains an equivalent preoperad which gives rise to Milgram's small model for when n=2 and is very closely related to Milgram's model of for n>2. 相似文献
100.
It is proved that the following conditions are equivalent for an arbitrary commutative Moufang loop
:1) the loop
is finite over the center;2) every subloop of
defines a finite conjugacy class of subloops;3) every associative subloop of
defines a finite conjugacy class of subloops;4) every infinite associative subloop of
defines a finite conjugacy class of subloops. 相似文献