With the effect of the human trade doctrine in the international trade field, almost all the countries have paid more attention to the sustainable development of international trade. This article chose the export sust...With the effect of the human trade doctrine in the international trade field, almost all the countries have paid more attention to the sustainable development of international trade. This article chose the export sustainable development as the research object. On the basis of the analysis of the theoretical connotation of the export sustainable development, this article tried to establish an evaluation indices system and set up an evaluation model of the export sustainable development level, and finally made some empirical research on China. The result indicates that the comprehensive level of the export sustainable development in China showed a tendency to rise from 1985 to 2003 and the export sustainable development level of China in these years can be divided into four grades: excellent, good, moderate and poor. In most years, the social economic benefits of export was obtained at the cost of the deterioration of environment and the depletion of resources, and the economic profit of export did not increase with the enlargement of the export scale because of the deterioration of the terms of trade. Therefore, China should be careful about the problem of poverty accompanied by the increase of export.展开更多
For the time-dependent harmonic oscillator and generalized harmonic oscillator with or without external forces in non-commutative space, wave functions, and geometric phases are derived using the Lewis-Riesenfeld inva...For the time-dependent harmonic oscillator and generalized harmonic oscillator with or without external forces in non-commutative space, wave functions, and geometric phases are derived using the Lewis-Riesenfeld invariant. Coherent states are obtedned as the ground state of the forced system. Quantum fluctuations are calculated too. It is seen that geometric phases and quantum fluctuations are greatly affected by the non-commutativity of the space.展开更多
ymmetry of the world trade network provides a novel perspective to understand the world-wide trading system. However, symmetry in the world trade network （WTN） has been rarely studied so far. In this paper, the auth...ymmetry of the world trade network provides a novel perspective to understand the world-wide trading system. However, symmetry in the world trade network （WTN） has been rarely studied so far. In this paper, the authors systematically explore the symmetry in WTN. The authors construct WTN in 2005 and explore the size and structure of its automorphism group, through which the authors find that WTN is symmetric, particularly, locally symmetric to a certain degree. Furthermore, the authors work out the symmetric motifs of WTN and investigate the structure and function of the symmetric motifs, coming to the conclusion that local symmetry will have great effect on the stability of the WTN and that continuous symmetry-breakings will generate complexity and diversity of the trade network. Finally, utilizing the local symmetry of the network, the authors work out the quotient of WTN, which is the structural skeleton dominating stability and evolution of WTN.展开更多
The Heisenberg commutation relation, QP P Q = ihI, is the most fundamental relation of quantum mechanics. Heisenberg's encoding of the ad-hoc quantum rules in this simple relation embodies the character-istic inde...The Heisenberg commutation relation, QP P Q = ihI, is the most fundamental relation of quantum mechanics. Heisenberg's encoding of the ad-hoc quantum rules in this simple relation embodies the character-istic indeterminacy and uncertainty of quantum theory. Representations of the Heisenberg relation in various mathematical structures are discussed. In particular, after a discussion of unbounded operators affiliated with finite von Neumann algebras, especially, factors of Type Ⅱ1 , we answer the question of whether or not the Heisenberg relation can be realized with unbounded self-adjoint operators in the algebra of operators affiliated with a factor of type Ⅱ1 .展开更多
基金assisted by the humanities and social sciences research Youth Fund Project of the Ministry of Education of China (Grant No. 06JC790008)
文摘With the effect of the human trade doctrine in the international trade field, almost all the countries have paid more attention to the sustainable development of international trade. This article chose the export sustainable development as the research object. On the basis of the analysis of the theoretical connotation of the export sustainable development, this article tried to establish an evaluation indices system and set up an evaluation model of the export sustainable development level, and finally made some empirical research on China. The result indicates that the comprehensive level of the export sustainable development in China showed a tendency to rise from 1985 to 2003 and the export sustainable development level of China in these years can be divided into four grades: excellent, good, moderate and poor. In most years, the social economic benefits of export was obtained at the cost of the deterioration of environment and the depletion of resources, and the economic profit of export did not increase with the enlargement of the export scale because of the deterioration of the terms of trade. Therefore, China should be careful about the problem of poverty accompanied by the increase of export.
文摘For the time-dependent harmonic oscillator and generalized harmonic oscillator with or without external forces in non-commutative space, wave functions, and geometric phases are derived using the Lewis-Riesenfeld invariant. Coherent states are obtedned as the ground state of the forced system. Quantum fluctuations are calculated too. It is seen that geometric phases and quantum fluctuations are greatly affected by the non-commutativity of the space.
基金supported by the National Natural Science Foundation of China under Grant No. 70371070 Shanghai Leading Academic Discipline Project under Grant No. S30504Key Project for Fundamental Research of STCSM under Grant No. 06JC14057
文摘ymmetry of the world trade network provides a novel perspective to understand the world-wide trading system. However, symmetry in the world trade network （WTN） has been rarely studied so far. In this paper, the authors systematically explore the symmetry in WTN. The authors construct WTN in 2005 and explore the size and structure of its automorphism group, through which the authors find that WTN is symmetric, particularly, locally symmetric to a certain degree. Furthermore, the authors work out the symmetric motifs of WTN and investigate the structure and function of the symmetric motifs, coming to the conclusion that local symmetry will have great effect on the stability of the WTN and that continuous symmetry-breakings will generate complexity and diversity of the trade network. Finally, utilizing the local symmetry of the network, the authors work out the quotient of WTN, which is the structural skeleton dominating stability and evolution of WTN.
文摘The Heisenberg commutation relation, QP P Q = ihI, is the most fundamental relation of quantum mechanics. Heisenberg's encoding of the ad-hoc quantum rules in this simple relation embodies the character-istic indeterminacy and uncertainty of quantum theory. Representations of the Heisenberg relation in various mathematical structures are discussed. In particular, after a discussion of unbounded operators affiliated with finite von Neumann algebras, especially, factors of Type Ⅱ1 , we answer the question of whether or not the Heisenberg relation can be realized with unbounded self-adjoint operators in the algebra of operators affiliated with a factor of type Ⅱ1 .
