The geochemical behaviors of hydrogen and oxygen isotopes in the hydrothermal system and their inher-ent relationship with the water / rock exchange are discussed in this paper In addition to the temperature con-ditio...The geochemical behaviors of hydrogen and oxygen isotopes in the hydrothermal system and their inher-ent relationship with the water / rock exchange are discussed in this paper In addition to the temperature con-ditions, the effective W / R ratio is another factor controlling the changes in H and O isotope compositions ofthe altered rock and hydrothermal water. Besides, the application and geological significance of the water-rockexchange theory are also discussed in the light of the H and O isotope compositions and their variation charac-teristics of the mineralizing hydrothermal water and altered rocks from several mineral deposits. Finally, abrief evolutional model of H and O istotope compositions of meteoric and magmatic hydrothermal waters in ahydrothermal system is given.展开更多
为了改善正交频分复用(orthogonal frequency division multiplexing,OFDM)系统的峰均功率比(peak-to-average power ratio,PAPR)性能,提出了一种基于动态功率阈值的低复杂度部分传输序列(partial transmit sequences,PTS)方法。在新的...为了改善正交频分复用(orthogonal frequency division multiplexing,OFDM)系统的峰均功率比(peak-to-average power ratio,PAPR)性能,提出了一种基于动态功率阈值的低复杂度部分传输序列(partial transmit sequences,PTS)方法。在新的PTS方法中,引入了基于功率的判别函数,并给出了一种基于功率合理选择阈值的方法。在选取最小的PAPR值进行传输时,只对Pn大于等于阈值的样本信号进行峰值功率的计算。与传统的PTS算法相比,本文提出的算法在保证PAPR性能和误码率的情况下,能够更有效地降低计算复杂度。展开更多
文摘The geochemical behaviors of hydrogen and oxygen isotopes in the hydrothermal system and their inher-ent relationship with the water / rock exchange are discussed in this paper In addition to the temperature con-ditions, the effective W / R ratio is another factor controlling the changes in H and O isotope compositions ofthe altered rock and hydrothermal water. Besides, the application and geological significance of the water-rockexchange theory are also discussed in the light of the H and O isotope compositions and their variation charac-teristics of the mineralizing hydrothermal water and altered rocks from several mineral deposits. Finally, abrief evolutional model of H and O istotope compositions of meteoric and magmatic hydrothermal waters in ahydrothermal system is given.
文摘为了改善正交频分复用(orthogonal frequency division multiplexing,OFDM)系统的峰均功率比(peak-to-average power ratio,PAPR)性能,提出了一种基于动态功率阈值的低复杂度部分传输序列(partial transmit sequences,PTS)方法。在新的PTS方法中,引入了基于功率的判别函数,并给出了一种基于功率合理选择阈值的方法。在选取最小的PAPR值进行传输时,只对Pn大于等于阈值的样本信号进行峰值功率的计算。与传统的PTS算法相比,本文提出的算法在保证PAPR性能和误码率的情况下,能够更有效地降低计算复杂度。