In this paper, an explicit N-fold Darboux transformation with multi-parameters for both a （1＋1）- dimensional Broer-Kaup （BK） equation and a （1＋1）-dimensional high-order Broer-Kaup equation is constructed with ...In this paper, an explicit N-fold Darboux transformation with multi-parameters for both a （1＋1）- dimensional Broer-Kaup （BK） equation and a （1＋1）-dimensional high-order Broer-Kaup equation is constructed with the help of a gauge transformation of their spectral problems. By using the Darboux transformation and new basic solutions of the spectral problems, 2N-soliton solutions of the BK equation, the high-order BK equation, and the Kadomtsev-Petviashvili （KP） equation are obtained.展开更多
In this paper,the results of spectral description and invertibility of upper triangle infinite-dimensionalHamiltonian operators with a diagonal domain are given.By the above results,it is proved that the infinite-dime...In this paper,the results of spectral description and invertibility of upper triangle infinite-dimensionalHamiltonian operators with a diagonal domain are given.By the above results,it is proved that the infinite-dimensionalHamiltonian operator associated with plane elasticity equations without the body force is invertible,and the spectrumof which is non-empty and is a subset of R.展开更多
Flows through an open cross-flow-type nano-hydraulic turbine are numerically simulated to investigate the effects of the clearance Hc between the rotor and the ground on the turbine performance. A two-dimensional part...Flows through an open cross-flow-type nano-hydraulic turbine are numerically simulated to investigate the effects of the clearance Hc between the rotor and the ground on the turbine performance. A two-dimensional particle method is employed, which was successfully used for flow simulations of impulse-type and open cross-flow-type nano-hydraulic turbines in the authors＇ previous works. When the clearance Hc is smaller than a critical value, the simulated turbine performance decreases with decreasing Hc, in good agreement with the experiment. The simulations make it clear that such a reduction of turbine performance is attributable to an increase in the circumferential component of the water velocity at the rotor outlet. The simulations also demonstrate that the effect of the tip speed ratio of the rotor on the relation between Hc and turbine performance can be analyzed.展开更多
The novel Ragtime, written by the contemporary American writer Edgar Lawrence Doctorow, imaginatively reconstructs the urban space in the Progressive Era. In the period of social transformation and change, all kinds o...The novel Ragtime, written by the contemporary American writer Edgar Lawrence Doctorow, imaginatively reconstructs the urban space in the Progressive Era. In the period of social transformation and change, all kinds of contradictions in New York City are becoming increasingly acute. The division of space reflects the power discourse of different classes, races, and genders. The connection, extension and expansion of space promote the features of urban modernity and open up new patterns of social behavior and opportunities for survival, but cannot fundamentally alleviate the capitalist crisis. Spatial layout and distribution of the city are not only the reflection of social relations, but also the ＂time capsule＂, bearing the history of the city, and the writing of space offers a mirror for the author＇s emotion and value judgment.展开更多
基金supported by the State Key Basic Research Program of China under Grant No.2004CB318000the Research Fund for the Doctoral Program of Higher Education of China under Grant No.20060269006
文摘In this paper, an explicit N-fold Darboux transformation with multi-parameters for both a （1＋1）- dimensional Broer-Kaup （BK） equation and a （1＋1）-dimensional high-order Broer-Kaup equation is constructed with the help of a gauge transformation of their spectral problems. By using the Darboux transformation and new basic solutions of the spectral problems, 2N-soliton solutions of the BK equation, the high-order BK equation, and the Kadomtsev-Petviashvili （KP） equation are obtained.
基金the National Natural Science Foundation of China under Grant No.10562002the Natural Science Foundation of Inner Mongolia under Grant No.200508010103
文摘In this paper,the results of spectral description and invertibility of upper triangle infinite-dimensionalHamiltonian operators with a diagonal domain are given.By the above results,it is proved that the infinite-dimensionalHamiltonian operator associated with plane elasticity equations without the body force is invertible,and the spectrumof which is non-empty and is a subset of R.
文摘Flows through an open cross-flow-type nano-hydraulic turbine are numerically simulated to investigate the effects of the clearance Hc between the rotor and the ground on the turbine performance. A two-dimensional particle method is employed, which was successfully used for flow simulations of impulse-type and open cross-flow-type nano-hydraulic turbines in the authors＇ previous works. When the clearance Hc is smaller than a critical value, the simulated turbine performance decreases with decreasing Hc, in good agreement with the experiment. The simulations make it clear that such a reduction of turbine performance is attributable to an increase in the circumferential component of the water velocity at the rotor outlet. The simulations also demonstrate that the effect of the tip speed ratio of the rotor on the relation between Hc and turbine performance can be analyzed.
文摘The novel Ragtime, written by the contemporary American writer Edgar Lawrence Doctorow, imaginatively reconstructs the urban space in the Progressive Era. In the period of social transformation and change, all kinds of contradictions in New York City are becoming increasingly acute. The division of space reflects the power discourse of different classes, races, and genders. The connection, extension and expansion of space promote the features of urban modernity and open up new patterns of social behavior and opportunities for survival, but cannot fundamentally alleviate the capitalist crisis. Spatial layout and distribution of the city are not only the reflection of social relations, but also the ＂time capsule＂, bearing the history of the city, and the writing of space offers a mirror for the author＇s emotion and value judgment.
