2,069 research outputs found
Recommended from our members
The First Supernova Explosions: Energetics, Feedback, And Chemical Enrichment
We perform three-dimensional smoothed particle hydrodynamics simulations in a realistic cosmological setting to investigate the expansion, feedback, and chemical enrichment properties of a 200M(circle dot) pair-instability supernova in the high-redshift universe. We find that the SN remnant propagates for a Hubble time at z similar or equal to 20 to a final mass-weighted mean shock radius of 2.5 kpc (proper), roughly half the size of the H II region, and in this process sweeps up a total gas mass of 2: 5; 10(5) M-circle dot. The morphology of the shock becomes highly anisotropic once it leaves the host halo and encounters filaments and neighboring minihalos, while the bulk of the shock propagates into the voids of the intergalactic medium. The SN entirely disrupts the host halo and terminates further star formation for at least 200 Myr, while in our specific case it exerts positive mechanical feedback on neighboring minihalos by shock-compressing their cores. In contrast, we do not observe secondary star formation in the dense shell via gravitational fragmentation, due to the previous photoheating by the progenitor star. We find that cooling by metal lines is unimportant for the entire evolution of the SN remnant, while the metal-enriched, interior bubble expands adiabatically into the cavities created by the shock, and ultimately into the voids with a maximum extent similar to the final mass-weighted mean shock radius. Finally, we conclude that dark matter halos of at least M-vir greater than or similar to 10(8) M-circle dot must be assembled to recollect all components of the swept-up gas.Astronom
The effect of cave illumination on bats
Artificial light at night has large impacts on nocturnal wildlife such as bats, yet its effect varies with wavelength of light, context, and across species involved. Here, we studied in two experiments how wild bats of cave-roosting species (Rhinolophus mehelyi, R. euryale, Myotis capaccinii and Miniopterus schreibersii) respond to LED lights of different colours. In dual choice experiments, we measured the acoustic activity of bats in response to neutral-white, red or amber LED at a cave entrance and in a flight room – mimicking a cave interior. In the flight room, M. capaccinii and M. schreibersii preferred red to white light, but showed no preference for red over amber, or amber over white light. In the cave entrance experiment, all light colours reduced the activity of all emerging species, yet red LED had the least negative effect. Rhinolophus species reacted most strongly, matching their refusal to fly at all under any light treatment in the flight room. We conclude that the placement and light colour of LED light should be considered carefully in lighting concepts for caves both in the interior and at the entrance. In a cave interior, red LED light could be chosen – if needed at all – for careful temporary illumination of areas, yet areas important for bats should be avoided based on the precautionary principle. At cave entrances, the high sensitivity of most bat species, particularly of Rhinolophus spp., towards light sources almost irrespective of colour, calls for utmost caution when illuminating cave entrances
The Taiwanese Perspective in Investigating Korean Confucianism: Lee Ming-huei's Interpretation of Han Wonjin (1682–1750)
Numerous representatives of the contemporary Confucian revival from Taiwan are increasingly demonstrating the fact that the development of Confucian philosophy has to be viewed in a broader cultural context, especially in the context of different East Asian regions. While the development of the Japanese Confucian studies has been elaborated to a great extent during the last decades, studies in Korean Confucianism are still rare. Hence, the present article aims to offer a report on a pioneer contribution in this regard. It introduces Lee Ming-huei’s investigation into the work of one of the most influential Korean Confucians of the Joseon period; on the basis of Huang Chun-chieh’s methodology which exposes the contextualization paradigm, the article explains the main hypotheses and offers a theoretical reflection of the main issues discussed in this research work. Številni predstavniki sodobnega konfucijanskega preporoda na Tajvanu izpostavljajo dejstvo, da je razvoj konfucijanske filozofije potrebno obravnavati iz širšega kulturnega konteksta, zlasti ko govorimo o različnih regijah Vzhodne Azije. Medtem ko je bil ravoj japonskih konfucijanskih študij v veliki meri izdelan v zadnjih desetletjih, so študije korejskega konfucianizma še vedno maloštevilne. Zato je cilj tega članka predstaviti pionirsko raziskavo iz tega področja. Članek predstavi raziskavo profesorja Lee Ming-hueija s področja del enega izmed najbolj vplivnih korejskih konfucijancev obdobja Joseon. Na podlagi Huang Chun-chieh-jeve metodologije, ki izpostavi kontekstualno paradigmo, razloži poglavitne hipoteze in ponudi kritičen razmislek o poglavitnih vprašanjih obravnavanih v tem raziskovalnem delu.
- …