Flexible Al/PVDF nanoenergetic film prepared by vacuum freeze-drying, possesses hydrophobicity, corrosion-resistant properties as well as outstanding energetic performances.
The stability of aluminum (Al) nanoparticles (ANPs) is a key issue that can determine the energetic properties of Al‐based energetic materials. In this study, a surface functionalization approach is employed, using the chemical adsorption and auto polymerization effects of the 1H, 1H, 2H, 2H‐perfluorodecyltriethoxysilane (FAS‐17), to set up a highly stable barrier coating to water and further endow ANPs with long‐term storage stability and self‐activation reaction capability. The FAS‐17‐modified ANPs (AFNPs) with a superhydrophobic surface show their excellent stability in air and unique strengths in corrosion resistance to water by enhancing diffusion resistance of O2 and preventing the hydration reaction. In terms of energetic performances, compared to the two‐step slow oxidation of ANPs, the heat‐release rate of AFNPs is significantly enhanced, resulting in a drastic oxidation process profiting from the surface reaction between the FAS‐17 and alumina (Al2O3) layer. More importantly, the ignition and combustion properties of AFNPs are also greatly improved, which can undergo self‐propagation combustion with a fairly high energy output even after stored in water. At last, the possible mechanisms of oxidation resistance and self‐activation reaction capacities are also proposed.
In the InSAR solution, the uneven distribution of permanent scatterer candidates (PSCs) or slowly decoherent filtering phase (SDFP) pixel density in a region of variable radar reflection feature can cause local low accuracy in single interferometry. PSCs with higher-order coherence in Permanent Scatter InSAR (PS-InSAR) are generally distributed in those point targets of urban built-up areas, and SDFP pixels in Small Baseline Subset InSAR (SBAS-InSAR) are generally distributed in those distributed targets of countryside vegetation areas. According to the respective reliability of PS-InSAR and SBAS-InSAR for different radar reflection features, a new land subsidence monitoring method is proposed, which combines PS-SBAS InSAR by data fusion of different interferometry in different radar reflection regions. Density-based spatial clustering of applications with noise (DBSCAN) clustering analysis is carried out on the density of PSCs with higher-order coherence in PS-InSAR processing to zone the region of variable radar reflection features for acquiring the boundary of data fusion. The vector monitoring data of PS-InSAR is retained in the dense region of PSCs with higher-order coherence, and the vector monitoring data of SBAS-InSAR is used in the sparse region of PSCs with higher-order coherence. The vertical displacements from PS-InSAR and SBAS-InSAR are integrated to obtain the optimal land subsidence. The verification case of 38 SAR images acquired by the Sentinel-1A in Suzhou city indicates that the proposed method can automatically choose a matched interferometry technique according to the variability of radar reflection features in the region and improve the accuracy of using a single interferometry method. The integrated method of the combined field is more representative of overall subsidence characteristics than the PS-InSAR-only or SBAS-InSAR-only results, and it is better suited for the assessment of the impact of land subsidence over the study area. The research results of this paper can provide a useful comprehensive reference for city planning and help decrease land subsidence in Suzhou.
In order to decrease the sensitivity and broaden the application of PETN, PETN/TKX-50 co-crystal with high energy and low sensitivity was prepared through the solvent/non-solvent method.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.