你知道凭证式国库券的利息是如何计算的吗？
凭证式国库券买卖时的利息如何计算？[{'character': '凭', 'pinyin': 'ping2', 'highest pitch': 9.93, 'lowest pitch': 8.45, 'duration': 0.28, 'prosody hierarchy': 'null'}, {'character': '证', 'pinyin': 'zheng4', 'highest pitch': 11.81, 'lowest pitch': 9.43, 'duration': 0.23, 'prosody hierarchy': 'null'}, {'character': '式', 'pinyin': 'shiii4', 'highest pitch': 9.56, 'lowest pitch': 6.78, 'duration': 0.22, 'prosody hierarchy': '#2'}, {'character': '国', 'pinyin': 'guo2', 'highest pitch': 8.9, 'lowest pitch': 6.78, 'duration': 0.18, 'prosody hierarchy': 'null'}, {'character': '库', 'pinyin': 'ku4', 'highest pitch': 10.38, 'lowest pitch': 8.9, 'duration': 0.16, 'prosody hierarchy': 'null'}, {'character': '券', 'pinyin': 'qvan4', 'highest pitch': 10.44, 'lowest pitch': 8.51, 'duration': 0.21, 'prosody hierarchy': '#1'}, {'character': '买', 'pinyin': 'mai3', 'highest pitch': 8.58, 'lowest pitch': 4.99, 'duration': 0.17, 'prosody hierarchy': 'null'}, {'character': '卖', 'pinyin': 'mai4', 'highest pitch': 10.06, 'lowest pitch': 4.99, 'duration': 0.23, 'prosody hierarchy': '#1'}, {'character': '时', 'pinyin': 'shiii2', 'highest pitch': 8.19, 'lowest pitch': 7.33, 'duration': 0.15, 'prosody hierarchy': 'null'}, {'character': '的', 'pinyin': 'de5', 'highest pitch': 8.04, 'lowest pitch': 6.78, 'duration': 0.1, 'prosody hierarchy': '#1'}, {'character': '利', 'pinyin': 'li4', 'highest pitch': 8.54, 'lowest pitch': 6.89, 'duration': 0.22, 'prosody hierarchy': 'null'}, {'character': '息', 'pinyin': 'xi5', 'highest pitch': 6.89, 'lowest pitch': 5.98, 'duration': 0.26, 'prosody hierarchy': '#3'}, {'pinyin': 'sp1', 'highest pitch': 0.0, 'lowest pitch': 0.0, 'duration': 0.06}, {'character': '如', 'pinyin': 'ru2', 'highest pitch': 10.54, 'lowest pitch': 7.39, 'duration': 0.18, 'prosody hierarchy': 'null'}, {'character': '何', 'pinyin': 'he2', 'highest pitch': 10.4, 'lowest pitch': 7.54, 'duration': 0.17, 'prosody hierarchy': '#1'}, {'character': '计', 'pinyin': 'ji4', 'highest pitch': 8.0, 'lowest pitch': 6.86, 'duration': 0.18, 'prosody hierarchy': 'null'}, {'character': '算', 'pinyin': 'suan4', 'highest pitch': 7.41, 'lowest pitch': 5.6, 'duration': 0.3, 'prosody hierarchy': '#4'}]