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The Mars surface is rugged and its environment is complex, the Mars UAVs provide a new idea for Mars exploration due to its high mobility and flexibility, and is an important paradigm for future deep space exploration.The differences between Mars and some relevant surface environmental parameters on Earth are compared, the main uses and difficulties that Mars UAVs need to be overcome are analyzed, and the importance of Mars UAV experimental platform is clarified. The technical features, functional advantages and disadvantages of the Mars UAV experimental platform developed by domestic and foreign research institutions are introduced in detail, and the need for the experimental platform to have a simulated Mars environment and measure relevant parameters is summarized. On this basis, the idea of building a Mars UAV experiment platform is proposed, the overall design ideas and thoughts are given, and the prospect of the application of the Mars aerodynamics experimental platform is made.

The achievement of dual carbon goals varies significantly across Chinese provinces due to the differences in resource endowments and socioeconomic development levels. These variations impose distinct pressures for transitioning along different socioeconomic development paths. Exploration of orderly carbon reduction paths for each province is, thus, crucial, but current predictions have not adequately integrated provincial development plans and carbon emission convergence trends. This study combines the Intergovernmental Panel on Climate Change (IPCC's) shared socioeconomic pathways (SSPs) with a dual-layer target-setting approach based on trends in carbon emissions and each province's five-year plans. The scalable stochastic impacts by regression on population, affluence, and technology (STIRPAT) model and ridge regression method were employed to identify the factors influencing carbon emissions. Carbon peak values and timing were then predicted for provinces under different scenarios. The results indicate that total carbon emissions are primarily influenced by provincial economic level and population, with spatial and temporal variations in the driving factors. Carbon emissions are ranked from low to high in the following order: SSP1, SSP2, and SSP5. Provinces were categorized into four tiers based on their peak times: early, on-time, delayed, and significantly delayed peaking. Under SSP1, 24 provinces would achieve carbon peaking as scheduled. Under SSP2, only 17 provinces would achieve carbon peaking on time. Among the first-tier provinces, Beijing and Shanghai would achieve peak carbon five to eight years ahead of schedule; the second-tier provinces of Henan, Fujian, Guangdong, and Inner Mongolia would achieve peak carbon by 2030; the third tier would achieve carbon peak before 2035; and the fourth tier would gradually reach peak carbon before 2050. Policy implications for differentiated carbon peak paths are proposed for different regions based on these findings. [ABSTRACT FROM AUTHOR]

Accurately identifying sources of flow loss and hydroacoustics and clarifying the mechanism of their generation are crucial for directing the optimal design of efficient and quiet pump-jet propulsors (PJPs). In this paper, numerical simulations of steady and unsteady flow are performed for a PJP equipped with pre-swirl stationary vanes, based on which both sources of flow loss and hydroacoustics are investigated at multi-level granularity. Analyses of flow efficiency and entropy generation rate are performed to identify the sources of flow loss, and analyses of thrust fluctuation and wall pressure fluctuation are conduced to identify the sources of hydroacoustics. The results indicate that the pressure drag accounts for 76% of the total drag and is mainly contributed from the stator and the duct, but the flow efficiency of the rotor is much smaller than that of the stator and the sources of the flow loss are mainly located at three regions of the rotating blades: the leading edge, the tip, and the corner of the suction surface. The hydroacoustic sources are mainly located at the leading edge and the tip of the rotating blades due to stator–rotor and duct–rotor interactions, respectively, but the Taylor's frozen turbulence hypothesis is inappropriate to describe the wake evolution of the stationary vanes owing to the potential interaction caused by the blade rotation. [ABSTRACT FROM AUTHOR]

Helmholtz resonator (HR) is widely used in various fields, but the classic HR usually should satisfy the acoustically compact condition, which limits the application range of the classic HR. This paper investigates analytically and numerically the acoustic performance of a HR in which the length of the neck is not limited under the acoustically compact conditions. An analytical model is developed for accurately and quickly predicting resonant frequencies and transmission loss of the Helmholtz resonator with an extended neck (HREN), and numerical simulations have been performed to validate the developed analytical model. Both the analytical and numerical studies reveal that the HREN has multiple resonant frequencies, and a method is developed for approximate and fast calculation of the multiple resonant frequencies. [ABSTRACT FROM AUTHOR]