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Having reviewed 1259 papers on cluster theory, we find that current cluster studies primarily discussed cluster phenomena from either a microlevel or mesolevel. We argue that studying relations among clusters would increase our understanding of clusters, and such a research topic is worth becoming a new research orientation for cluster theory.

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In the present paper, extremely unsteady shock wave buffet induced by strong shock wave/boundary-layer interactions (SWBLI) on the upper surface of an OAT15A supercritical airfoil at Mach number of 0.73 and angle of attack of 3.5 degrees is first numerically simulated by IDDES, one of the most advanced RANS/LES hybrid methods. The results imply that conventional URANS methods are unable to effectively predict the buffet phenomenon on the wing surface; IDDES, which involves more flow physics, predicted buffet phenomenon. Some complex flow phenomena are predicted and demonstrated, such as periodical oscillations of shock wave in the streamwise direction, strong shear layer detached from the shock wave due to SWBLI and plenty of small scale structures broken down by the shear layer instability and in the wake. The root mean square (RMS) of fluctuating pressure coefficients and streamwise range of shock wave oscillation reasonably agree with experimental data. Then, two vortex generators (VG) both with an inclination angle of 30 degrees to the main flow directions are mounted in front of the shock wave region on the upper surface to suppress shock wave buffet. The results show that shock wave buffet can be significantly suppressed by VGs, the RMS level of pressure in the buffet region is effectively reduced, and averaged shock wave position is obviously pushed downstream, resulting in increased total lift. supercritical airfoil, vortex generator, shock wave buffet PACS number(s): 47.20.lb, 47.40.Hg, 47.85.L- Citation:Huang J B, Xiao Z X, Liu J, et al. Simulation of shock wave buffet and its suppression on an OAT15A supercritical airfoil by IDDES.

U.S. multinational corporations increasingly use intra-firm, cross-border research collaboration to disperse R&D across different countries. This paper investigates the implications of such collaboration on the abilities of firms to garner benefits from R&D tax incentives. We find that the association between R&D intensity and tax incentives is three to five times larger when firms have extensive cross-border collaboration connected to a country. We also find that the effect is stronger when local intellectual property protection is weaker and when local innovation resources are higher. Our results suggest that cross-border collaboration helps firms achieve more tax-efficient R&D investments both by reducing the nontax frictions posed by weak intellectual property protection and by increasing the nontax benefits of foreign R&D.

Animated films undoubtedly play important roles in Children growth. Disney movie, as a typical American media product, enjoys a growing global popularity and influence the young audience particularly in family values or even in their socialization. Finding Dory is a popular animation among children especially aged 5-6 and it presents children of this age 1. how to face failure and 2. how to balance self-benefit and supporting friends. This paper samples Chinese kids aged from 5-6 with qualitative analysis to reveal the effects of Finding Dory on the socialization of particular aged children. Although the research is limited by children’ language proficiency and parent’s personal guidance, but it definitely set implications on how to make full advantages of those animated movies to pattern socialization for children at this particular age.

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