{'fraction_non_alphanumeric': 0.028052805280528052, 'fraction_numerical': 0.0231023102310231, 'mean_word_length': 5.00990099009901, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Materials For Radiative Cooling To Low Temperatures

The clear sky can act as a heat sink. Cooling to low temperatures is possible with materials which are strongly emitting in the 8-13-μm band and non-absorbing elsewhere. In this paper we discuss the resource for radiative cooling and its implementation with thin solid films (Si00.6N0.2 coatings on Al) and with slabs of certain gases (C2H4, C2H40, and NH3 backed by Al). Results are given on spectrophotometric infrared reflectance and transmittance, computed parameters which govern the predicted cooling performance, and some preliminary field tests.