Heat-balance Thermal Protection with Heat Pipes for Hypersonic Vehicle

Heat-balance thermal protection is non-ablating thermal protection for leading edge of hypersonic vehicle. Heat will be quickly transferred from high aerodynamic heating area to low aerodynamic heating area, where the energy will be released by radiation. The temperature of high aerodynamic heating area could be reduced to protect the designed structure from being burned down. Heat-balance thermal protection is summarized. The research on heat-pipe for heat-balance thermal protection is introduced

Heat-balance Thermal Protection with Heat Pipes for Hypersonic Vehicle

Heat-balance thermal protection is non-ablating thermal protection for leading edge of hypersonic vehicle. Heat will be quickly transferred from high aerodynamic heating area to low aerodynamic heating area, where the energy will be released by radiation. The temperature of high aerodynamic heating area could be reduced to protect the designed structure from being burned down. Heat-balance thermal protection is summarized. The research on heat-pipe for heat-balance thermal protection is introduced

Preliminary Study on Heavy Metal Pollution Status of Farmland Soil at Two Sides of Cheng-Guan Expressway

The heavy metal content of the farmland soil at two sides of Cheng-Guan Expressway is measured to make a preliminary evaluation on its heavy metal pollution status. After digestion and volume fixation of the soil samples collected, measure the Cu, Zn, Cd, Pb and Cr content with atomic absorption spectrophotometry and evaluate the measured data according to Level Two of National Soil Environmental Quality Standard to obtain the contamination status. Cu, Zn and Cd content of the farmland soil for sections of Cheng-Guan Expressway goes beyond Level Two of National Soil Environmental Quality Standard, while the Pb and Cr content meets Level Two of National Soil Environmental Quality Standard. Pb and Cr content of the farmland soil at two sides of Cheng-Guan Expressway is in safe state, while the Cu, Zn and Cd content is in a mild contamination state. Cu, Zn and Cd are the main pollution elements

Coexistence mechanism of ecological specialists and generalists based on a network dimension reduction method

Abstract As an ecological strategy for species coexistence, some species adapt to a wide range of habitats, while others specialize in particular environments. Such ‘generalists’ and ‘specialists’ achieve normal ecological balance through a complex network of interactions between species. However, the role of these interactions in maintaining the coexistence of generalist and specialist species has not been elucidated within a general theoretical framework. Here, we analyze the ecological mechanism for the coexistence of specialist and generalist species in a class of mutualistic and competitive interaction ecosystems based on the network dimension reduction method. We find that ecological specialists and generalists can be identified based on the number of their respective interactions. We also find, using real‐world empirical network simulations, that the removal of ecological generalists can lead to the collapse of local ecosystems, which is rarely observed with the loss of ecological specialists

Hierarchical domain structures associated with oxygen octahedra tilting patterns in lead-free (Bi1/2Na1/2)TiO3

Hierarchical domain structures associated with oxygen octahedra tilting patterns were observed in lead-free (Bi1/2Na1/2)TiO3 ceramics using aberration-corrected high-resolution transmission electron microscopy (HRTEM). Three types of domains are induced by distinct mechanisms: the "orientation-domain" is induced at micrometer scale formed by different tilting orientations of the oxygen octahedra, the "meso-chemical-domain" occurs at a few tens of nanometer scale by chemical composition variation on the A-site in the ABO3 perovskite structure, and the "nano-cluster-region" runs across several unit-cells with apparent A-site cation segregation with oxygen vacancies clustering around Na cations. Based on HRTEM amplitude contrast imaging (ACI), the correlation between the oxygen octahedral tilting pattern and compositional non-stoichiometry was established. The role of the hierarchical domain structure associated with the tilting patterns of the oxygen octahedra on the ferroelectric behavior of (Bi1/2Na1/2)TiO3 is also discussed.This is the Accepted Manuscript version of an article accepted for publication in Nanotechnology. IOP Publishing Ltd is not responsible for any errors or omissions in this version of the manuscript or any version derived from it.  The Version of Record is available online at DOI: 10.1088/1361-6528/aca030. Copyright 2022 IOP Publishing Ltd. CC BY-NC-ND 3.0. Posted with permission.