In our context,the planetary many-body problem consists of studying the motion of(n+1)-bodies under the mutual attraction of gravitation,where n planets move around a massive central body,the Sun.We establish the exis...In our context,the planetary many-body problem consists of studying the motion of(n+1)-bodies under the mutual attraction of gravitation,where n planets move around a massive central body,the Sun.We establish the existence of real analytic lower dimensional elliptic invariant tori with intermediate dimension N lies between n and 3n-1 for the spatial planetary many-body problem.Based on a degenerate KolmogorovArnold-Moser(abbr.KAM)theorem proved by Bambusi et al.(2011),Berti and Biasco(2011),we manage to handle the difficulties caused by the degeneracy of this real analytic system.展开更多
Electrons are believed to avoid one another in space(correlation) due to the Coulomb repulsion and/or the Pauli exclusion principle.It is shown, using examples of two-electron systems, that indeed the mean electron-el...Electrons are believed to avoid one another in space(correlation) due to the Coulomb repulsion and/or the Pauli exclusion principle.It is shown, using examples of two-electron systems, that indeed the mean electron-electron distance increases in case of the ground electronic state as compared to the independent electron model. It is demonstrated however that there exist excited states, often of low energy, in which the electrons, while having a lot of free physical space(with nuclei being absent), choose to be close to each other in their motion("anticorrelation"), as if they mutually attracted one another. The source of this effect, quantummechanical in nature, is the orthogonality of the eigenfunctions, that forces the electronic wave functions to differ widely, even at the price of short electron-electron distances. There are also excited states with a mixed behaviour, with complex and often intriguing correlation-anticorrelation patterns.展开更多
From Bethe-Salpeter equation,we deduce the equation which describes the two-body system consisting of a scalar meson and a vector meson.This equation is applied to investigate the exotic narrow state X (3872) assumed ...From Bethe-Salpeter equation,we deduce the equation which describes the two-body system consisting of a scalar meson and a vector meson.This equation is applied to investigate the exotic narrow state X (3872) assumed as a molecule state composed of D 0 0.The contribution of the resonance 0 is the attractive interaction between two heavy mesons in this molecule state.The calculated mass of X is consistent with the experimental data.展开更多
Disentangling the influence of multiple signal components on receivers and elucidating general processes influencing complex signal evolution are difficult tasks. In this study we test mate preferences of female squir...Disentangling the influence of multiple signal components on receivers and elucidating general processes influencing complex signal evolution are difficult tasks. In this study we test mate preferences of female squirrel treefrogs Hyla squirella and female tungara frogs Physalaemus pustulosus for similar combinations of acoustic and visual components of their multimodal courtship signals. In a two-choice playback experiment with squirrel treefrogs, the visual stimulus of a male model significantly increased the attractivness of a relatively unattractive slow call rate. A previous study demonstrated that faster call rates are more attractive to female squirrel treefrogs, and all else being equal, models of male frogs with large body stripes are more attractive. In a similar experiment with female tungara frogs, the visual stimulus of a robotic frog failed to increase the attractiveness of a relatively unattractive call. Females also showed no preference for the distinct stripe on the robot that males commonly bear on their throat. Thus, features of conspicuous signal components such as body stripes are not universally important and signal function is likely to differ even among species with similar ecologies and communication systems. Finally, we discuss the putative information content of anuran signals and suggest that the categorization of redundant versus multiple messages may not be sufficient as a general explanation for the evolution of multimodal signaling. Instead of relying on untested assumptions concerning the information content of signals, we discuss the value of initially collecting comparative empirical data sets related to receiver responses.展开更多
We generalize the computations of the long-range interactions between two parallel stacks of branes to various cases when two stacks of branes are not placed parallel to each other. We classify the nature of interacti...We generalize the computations of the long-range interactions between two parallel stacks of branes to various cases when two stacks of branes are not placed parallel to each other. We classify the nature of interaction(repulsive or attractive) for each special case and this classification can be used to justify the nature of long-range interaction between two complicated brane systems such as brane bound states. We will provide explicit examples in this paper to demonstrate this.展开更多
After assuming the Chinese presidency in March 2013, Xi Jinping introduced the new political slogan "the Chinese Dream," which he does not only address to the domestic audience but also aims to promote to the world....After assuming the Chinese presidency in March 2013, Xi Jinping introduced the new political slogan "the Chinese Dream," which he does not only address to the domestic audience but also aims to promote to the world. Since his inaugural trip abroad, Xi has repeatedly speeches when addressing international catchphrase received as much appeal as used the term "Chinese Dream" in his audiences. However, nowhere has the in Africa. Simultaneously, African academics and other interested parties have observed the promotion of the idea of an African Dream by the Chinese Communist Party (CCP) with great suspicion as they view it simply as a projection of China's own foreign policy onto Africa. But what do the Chinese Dream and African Dream actually mean? How can we make sense out of these terms? In order to decode or demystify the meaning behind the Chinese Dream narrative in the context of China's foreign policy, this paper argues that it is essential to examine how it is constructed and projected to the international audience, in particular to Africa. The Chinese Dream is understood as a narrative which is strategically used by the CCP in order to shape perceptions and behavior of other international actors according to their own agenda. Moreover, the dynamic interactions between the media and politics and how they impinge on the formation and projection of the Chinese Dream and African Dream narrative will also be taken into account.展开更多
文摘In our context,the planetary many-body problem consists of studying the motion of(n+1)-bodies under the mutual attraction of gravitation,where n planets move around a massive central body,the Sun.We establish the existence of real analytic lower dimensional elliptic invariant tori with intermediate dimension N lies between n and 3n-1 for the spatial planetary many-body problem.Based on a degenerate KolmogorovArnold-Moser(abbr.KAM)theorem proved by Bambusi et al.(2011),Berti and Biasco(2011),we manage to handle the difficulties caused by the degeneracy of this real analytic system.
文摘Electrons are believed to avoid one another in space(correlation) due to the Coulomb repulsion and/or the Pauli exclusion principle.It is shown, using examples of two-electron systems, that indeed the mean electron-electron distance increases in case of the ground electronic state as compared to the independent electron model. It is demonstrated however that there exist excited states, often of low energy, in which the electrons, while having a lot of free physical space(with nuclei being absent), choose to be close to each other in their motion("anticorrelation"), as if they mutually attracted one another. The source of this effect, quantummechanical in nature, is the orthogonality of the eigenfunctions, that forces the electronic wave functions to differ widely, even at the price of short electron-electron distances. There are also excited states with a mixed behaviour, with complex and often intriguing correlation-anticorrelation patterns.
文摘From Bethe-Salpeter equation,we deduce the equation which describes the two-body system consisting of a scalar meson and a vector meson.This equation is applied to investigate the exotic narrow state X (3872) assumed as a molecule state composed of D 0 0.The contribution of the resonance 0 is the attractive interaction between two heavy mesons in this molecule state.The calculated mass of X is consistent with the experimental data.
文摘Disentangling the influence of multiple signal components on receivers and elucidating general processes influencing complex signal evolution are difficult tasks. In this study we test mate preferences of female squirrel treefrogs Hyla squirella and female tungara frogs Physalaemus pustulosus for similar combinations of acoustic and visual components of their multimodal courtship signals. In a two-choice playback experiment with squirrel treefrogs, the visual stimulus of a male model significantly increased the attractivness of a relatively unattractive slow call rate. A previous study demonstrated that faster call rates are more attractive to female squirrel treefrogs, and all else being equal, models of male frogs with large body stripes are more attractive. In a similar experiment with female tungara frogs, the visual stimulus of a robotic frog failed to increase the attractiveness of a relatively unattractive call. Females also showed no preference for the distinct stripe on the robot that males commonly bear on their throat. Thus, features of conspicuous signal components such as body stripes are not universally important and signal function is likely to differ even among species with similar ecologies and communication systems. Finally, we discuss the putative information content of anuran signals and suggest that the categorization of redundant versus multiple messages may not be sufficient as a general explanation for the evolution of multimodal signaling. Instead of relying on untested assumptions concerning the information content of signals, we discuss the value of initially collecting comparative empirical data sets related to receiver responses.
基金Supported by National Natural Science Foundation of China under Grant No.11235010
文摘We generalize the computations of the long-range interactions between two parallel stacks of branes to various cases when two stacks of branes are not placed parallel to each other. We classify the nature of interaction(repulsive or attractive) for each special case and this classification can be used to justify the nature of long-range interaction between two complicated brane systems such as brane bound states. We will provide explicit examples in this paper to demonstrate this.
文摘After assuming the Chinese presidency in March 2013, Xi Jinping introduced the new political slogan "the Chinese Dream," which he does not only address to the domestic audience but also aims to promote to the world. Since his inaugural trip abroad, Xi has repeatedly speeches when addressing international catchphrase received as much appeal as used the term "Chinese Dream" in his audiences. However, nowhere has the in Africa. Simultaneously, African academics and other interested parties have observed the promotion of the idea of an African Dream by the Chinese Communist Party (CCP) with great suspicion as they view it simply as a projection of China's own foreign policy onto Africa. But what do the Chinese Dream and African Dream actually mean? How can we make sense out of these terms? In order to decode or demystify the meaning behind the Chinese Dream narrative in the context of China's foreign policy, this paper argues that it is essential to examine how it is constructed and projected to the international audience, in particular to Africa. The Chinese Dream is understood as a narrative which is strategically used by the CCP in order to shape perceptions and behavior of other international actors according to their own agenda. Moreover, the dynamic interactions between the media and politics and how they impinge on the formation and projection of the Chinese Dream and African Dream narrative will also be taken into account.