Abstract-Positive discourse analysis on leaders' speeches has gained much attention from many scholars at home and abroad. However, the author finds that there is few related research on Chinese leaders' speech. Therefore, the paper chooses President Xi Jinping's speech, delivered at the National University of Singapore on November 7 th , 2015, as the research subject and conducts the positive discourse analysis from three aspects: attitude system, engagement system and graduation system. After the analysis, the author comes to find that there are more positive resources in Mr. Xi's speech in order to construct a harmonious relationship with his listeners; Mr. Xi is careful to introduce other voices in terms of the engagement system; he adopts more up-scaling force than the down-scaling force, more sharpened force than softened force in terms of the graduation system. The present paper is significant in applying positive discourse analysis to Chinese leader's speech, thus expanding its application scope; in enriching the research content of appraisal theory; and in opening up a new angle for future study.

In this paper, we study an integrable Camassa–Holm hierarchy whose high-frequency limit is the Camassa–Holm equation. By a method associated with the Darboux transform, we construct the explicit multi-soliton and multi-cuspon solutions. Then, we study in detail the interactions of soliton–cuspon and soliton–soliton. Further, an interesting phenomenon is found: the soliton with smaller amplitude can travel faster than the one with larger amplitude when they interact. At last, we investigate in detail the head-on collision of one soliton and one cuspon.

In this paper, the rising dynamics of a two-dimensional single bubble in the duct is systematically studied by using an improved phase field lattice Boltzmann (LB) multiphase model. This model enables to handle multiphase flows with mass conservation and high density ratio, up to the order of [Formula: see text], which are unavailable in the LB community. The model is first validated by simulating bubble rising problem with the density ratio of 1000 and numerical solutions for bubble shape and position agree well with the previous literature data. Then, it is used to study single bubble rising through a quiescent liquid. The dynamic behavior of the bubble and rising velocity are shown, and the influences of several important physical quantities, including the Eotvos number, Reynolds number, density ratio, viscosity ratio, bubble size and initial bubble shape, are investigated in detail. The numerical results show that the bubble undergoes a great deformation with the increase of the Eotvos number or Reynolds number, and even could break up into multiple satellite bubbles at a sufficiently large value of Eotvos number or Reynolds number. Several classic terminal bubble shapes are also successfully produced in the system. The terminal rising velocity of bubble at equilibrium shows to present an initial increase with the Eotvos number and finally decreases with it, while increasing the Reynolds number could enhance the bubble rising velocity. Both the density ratio and viscosity ratio have less influence on the terminal shape of the bubble, while a greater influence on the rising velocity is reported for the density ratio smaller than 20 and it seems to be independent of the viscosity ratio. At last, we discuss the effects of the bubble size and initial bubble shape. It is found that bubble size has little influence on terminal bubble shape, but decreasing the bubble size can improve the bubble terminal velocity. On the other hand, both the deformation and terminal velocity of the bubble are found to no longer change much with its initial shape.

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buildings and nuclear power plant equipment and structures. The chapter developed by C. W. Lin is general and contains papers that complement specific topics covered in other chapters.As long as earthquakes occur, there is a challenge to improve the reliability of engineered systems to withstand the forces of nature. New knowledge will continue to be developed. The 67 papers in this volume collectively represent our understanding of this technology today.