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121.
The usual concepts of the dynamics of an overloaded solute band fail to explain several phenomena such as the typical “leading-tail” shape and retention deviations exhibited by overloaded peaks, and why these defects are more commonly observed in short columns. These and other related deviations from theory can be rationalized by a non-classical approach to the overloading phenomenon. 相似文献
122.
Minimal Length Elements of Thompson's Group F 总被引:1,自引:1,他引:0
S. Blake Fordham 《Geometriae Dedicata》2003,99(1):179-220
Elements of the group are represented by pairs of binary trees and the structure of the trees gives insight into the properties of the elements of the group. The review section presents this representation and reviews the known relationship between elements of F and binary trees. In the main section we give a method of determining the minimal lengths of elements of Thompson's group F in the two generator presentation
This method is an effective algorithm in that its order is linear in the size of the trees representing an element of F. We also give a method for constructing all minimal length representatives of an element in F. 相似文献
123.
Generalized Bicyclic Semigroups and Jones Semigroups 总被引:1,自引:0,他引:1
In this paper, we consider the generalized bicyclic semigroups Bn = a, b | anb = 1 and the Jones semigroups An = a, b | an+1b = a. They are the generalizations of the bicyclic semigroup B = a, b | ab = 1 and its analogous semigroup A = a, b | a2b = a discovered by P.R., Jones in 1987. The word problem for these kinds of semigroups is solved. It is proved that, for n 2, Bn are bisimple right inverse but not inverse semigroups and that the semigroup C = a, b | a2b = a, ab2 = b is the smallest idempotent-free homomorphic image of An. Moreover, we also prove that An and Am are mutually embeddable but not isomorphic with each other if n m. As a consequence, different kind of
-nontrivial [0-]simple semigroups without idempotents are discussed.AMS 1991 Subject Classification: primary 20M10 secondary 20M05.Supported by NNSF of China (19671063) and KSRF of Sichuan Education Committee ([1999]127). 相似文献
124.
Mark L. Lewis 《Algebras and Representation Theory》2001,4(5):469-489
Let G be a solvable group with five character degrees. We show that the derived length of G is at most 5. This verifies that the Taketa inequality, dl(G)|cd(G)|, is valid for solvable groups with at most five character degrees. 相似文献
125.
The ground state energy per particle of a dilute, homogeneous, two-dimensional Bose gas, in the thermodynamic limit is shown rigorously to be E0/N=(22/m)|ln(a2)|–1, to leading order, with a relative error at most O(|ln(a2)|–1/5). Here N is the number of particles, =N/V is the particle density and a is the scattering length of the two-body potential. We assume that the two-body potential is short range and nonnegative. The amusing feature of this result is that, in contrast to the three-dimensional case, the energy, E0 is not simply N(N–1)/2 times the energy of two particles in a large box of volume (area, really) V. It is much larger. 相似文献
126.
Doo-Hee Chang Seung-Ho Jeong Bong-Guen Hong Kyu-Sun Chung Gon-Ho Kim Jae-Shin Lee 《Current Applied Physics》2001,1(6):497
The radial profiles of KT-1 tokamak (major radius of 27 cm, minor radius of 4.25 cm, two poloidal stainless-steel limiters) edge plasma parameters are measured using single and triple electric probes. The particle transport parameters are calculated from the measured edge plasma parameters, and the results are analyzed by the simple fluid approximations. The cross-field particle diffusion coefficient (D) in the boundary plasma of the KT-1 is calculated from the density scrape-off length (λn) measured by using a triple probe. The particle density and electron temperature fall exponentially in the radial direction with the e-folding length of λn=0.13 cm and λe=0.41 cm, respectively. From the scrape-off layer (SOL) model, the experimental values of scrape-off length (λn) is used to calculate the cross-field diffusion coefficient (D=1.2×103cm2/s), roughly corresponding to one third of the typical Bohm value. A simple SOL model with the contribution of recombination is introduced to evaluate the Bohm diffusion in the KT-1 tokamak edge plasma. Cross-field heat conductivity calculated from these deduced values is 5.2D in the SOL of KT-1 edge plasma. These results provide the finally certain information for edge particle transport in the KT-1 boundary plasmas. 相似文献
127.
A. S. Sivatski 《Algebra Colloquium》2000,7(2):197-204
Let A be a commutative ring and n 3 a positive integer. In this paper, we consider unimodular rows (f1(x),..., fn(x)) over A[x]. We prove that, if the row of the leading coefficients of fi(x) is unimodular over A and a A, then there exists En(A[x]) such that (f1(x),...,fn(x)) = (f1(a),...,fn(a)). Also, if A is a Noetherian ring with finite Krull dimension and the row of leading coefficients satisfies the same condition, then we give a bound for the length of in terms of elementary transvections.Partially supported by INTAS 93–436EXT and DFG–RFBR grant No. 96–01–00092G.2000 Mathematics Subject Classification: 19A13, 19B14, 13C10, 13B25, 13F20 相似文献
128.
Carl H. FitzGerald Frederick Weening 《Transactions of the American Mathematical Society》2000,352(2):485-513
We consider a generalization of the parallel slit uniformization in which the angle of inclination of each image slit is assigned independently. Koebe proved that for domains of finite connectivity there is, up to a normalization, a unique rectilinear slit map achieving any given angle assignment. Koebe's theorem is partially extended to domains of infinite connectivity. A uniqueness result is shown for domains of countable connectivity and arbitrary angle assignments, and an existence result is proved for arbitrary domains under the assumption that the angle assignment is continuous and has finite range. In order to prove the existence result a new extremal length tool, called the crossing-module, is introduced. The crossing-module allows greater freedom in the family of admissible arcs than the classical module. Several results known for the module are extended to the crossing-module. A generalization of Jenkins' module condition for the parallel slit problem is given for the rectilinear slit problem in terms of the crossing-module and it is shown that rectilinear slit maps satisfying this crossing-module condition exist.
129.
130.