388 research outputs found
Research on Green Transformation of Campus Sponge and Energy Saving Facilities on Sloping Land
Based on the renovation of sponge and energy-saving facilities in a middle school in Nanning, this paper systematically studies the overall elevation of the campus, the composition of the drainage system and the layout of space functions, and formulates a characteristic scheme for the renovation of sponge and energy-saving facilities according to the characteristics of the sloping campus. In order to control the total amount of rainwater runoff, the sponge transformation mainly adopts the transformation methods of partition catchment, upper storage and lower use, multi-stage detection and classification treatment. For the purpose of solar energy and wind energy utilization, solar photovoltaic panels and small-scale wind power generation system are adopted. The application effects of sponge and energy-saving facilities are estimated and evaluated
Black Holes with Multiple Photon Spheres
Recently, asymptotically-flat black holes with multiple photon spheres have
been discovered and found to produce distinctive observational signatures. In
this paper, we focus on whether these black hole solutions are physically
viable, e.g., satisfying energy conditions of interest. Intriguingly, black
hole and naked singularity solutions with two photon spheres and one
anti-photon sphere are shown to exist in physically reasonable models, which
satisfy the null, weak, dominant and strong energy conditions. Our findings
reveal that black holes with multiple photon spheres may not be frequent, but
they are not exotic.Comment: 25 pages, 8 figures, references adde
- …