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As an emerging business modality and Internet format, live streaming e-commerce has developed rapidly since its emergence in 2016, especially since the outbreak of the COVID-19 epidemic in late 2019, when an increasing number of businesses from other industries attracted participation. However, with the development of the live streaming e-commerce industry, the industry's market environment is becoming increasingly chaotic. Therefore, during this period, government departments continuously formulate and implement relevant industry policies. In order to exploring the cooperation network structure, policy content distribution, and implementation effectiveness characteristics among publishers, this paper constructs a three-dimensional analysis framework of policy from the perspective of policy tools, policy effectiveness evaluation and policy publishers. The results show that in terms of policy tools, the overall structure of policy tools in the live streaming e-commerce industry is unreasonable, and different types of policy tools are significantly diverse. The proportion of environmental policy tools is greater than that of demand-based and supply-based policy tools, accounting for 62.97%, and among them, the tools related to industry regulation and management account for the largest proportion of the total, which greatly suppresses the enthusiasm of various entities in the industry for development. In terms of policy effectiveness evaluation, most of the policies do not formulate detailed long-, medium-, or short-term goals, nor are the policy priorities, incentive measures, or action modes perfect, indicating that the government's pushing and pulling forces for the live streaming e-commerce industry are insufficient. Finally, in the subject dimension of policy release, the synergy of relevant subjects is constantly improving, but there is also a phenomenon of over-concentration in the synergistic departments. [ABSTRACT FROM AUTHOR]

• Topological acoustic rainbow trapping can be realized by regulating topological edge mode dispersion curve and group velocity. • The topological phononic crystal is robust to multiple structural disorders, such as scaling, rotating and removing unit cells. • The proposed gradient phononic crystal is capable of recovering the Gaussian pulse signal from the background noise. In this letter, a gradient phononic crystal (PC) structure is proposed for robust enhanced acoustic sensing. At first, the topologically protected edge states are introduced by breaking the space-inversion symmetry of the PC structure. Then, the topological edge mode dispersion curve and group velocity are demonstrated to be regulated by varying the structure parameters gradually and the edge states can be slowed down to zero group velocity and trapped at different positions. Consequently, topological acoustic rainbow trapping is formed. Furthermore, the robustness and enhancement properties are verified both numerically and experimentally. All the results indicate that the gradient PC structure is able to realize robust enhanced acoustic sensing. This work opens a new vista to improve the robustness of the PC-based enhanced acoustic sensing. [ABSTRACT FROM AUTHOR]