High spin states of 84Sr were populated through the reaction 70Zn(18O,4n)84Sr at 75 MeV beam energy.Measurement of excitation function,γ-γ coincidences,directional correlation from oriented state (DCO) ratios and γ...High spin states of 84Sr were populated through the reaction 70Zn(18O,4n)84Sr at 75 MeV beam energy.Measurement of excitation function,γ-γ coincidences,directional correlation from oriented state (DCO) ratios and γ-transition intensities were performed using eight anticompton HPGe detectors and one planar HPGe detector.Based on the measured results,a new level scheme of 84Sr was established in which 12 new states and nearly 30 new γ-transitions were identified in the present work.The positive-parity states of the new level scheme were compared with the results from calculations in the framework of the projected shell model (PSM).One negative-parity band was extended to spin Iπ=19-and it can be found that in the high spin states,the γ-transition energies show the nature of signature staggering.The negative-parity band levels are in good agreement with deformed configuration-mixing shell model (DCM) calculations.展开更多
The level structure of ^19Opt has been studied experimentally using the ^176yb （^18O, 4n） reaction at beam energies of 88 and 95 MeV. γ-γ-t coincidence measurements were carried out. Based on the analysis of T-T ...The level structure of ^19Opt has been studied experimentally using the ^176yb （^18O, 4n） reaction at beam energies of 88 and 95 MeV. γ-γ-t coincidence measurements were carried out. Based on the analysis of T-T coincidence relationships, the level scheme of ^190Pt is extended to high-spin states. A new structure built on the 3413.6 keV 14＋ state has been observed, and the ＂vi13/2^-2 vh9/2^-1 vj （j = P3/2 or f5/2） configuration is tentatively assigned to it.展开更多
直流偏置光正交频分复用(DC-biased optical orthogonal frequency division multiplexing,DCO-OFDM)可见光通信(visible light communication,VLC)系统具有较高的峰均功率比(peak-to-average power ratio,PAPR)。为解决此问题,提出一...直流偏置光正交频分复用(DC-biased optical orthogonal frequency division multiplexing,DCO-OFDM)可见光通信(visible light communication,VLC)系统具有较高的峰均功率比(peak-to-average power ratio,PAPR)。为解决此问题,提出一种联合限幅和归一化μ律压扩算法抑制DCO-OFDM系统的PAPR。首先,该联合算法利用限幅操作对时域信号中的大峰值信号进行削波来降低信号的幅值;其次,对限幅后的信号再进行压扩变换。通过这种联合算法,DCO-OFDM系统的PAPR可以显著降低。实验仿真结果表明,当采用16QAM调制方式,互补累计函数的值为10^(-3)时,相比较于联合限幅和传统μ律压扩算法,此联合算法的PAPR下降了约2.206 dB。展开更多
基金supported by the Major State Basic Research Development Program in China (Grant No. 2007CB815003)the National Natural Science Foundation of China (Grant Nos. 11065001, 10547140, 10525520,60476043,10675170,10475002 and 10775064)+4 种基金the U.S. National Science Foundation (Grant No. 0500291)the Southeastern Universities Research Association,the Natural Science Foundation of Jiangxi Province (Grant Nos. 0612003 and 2007GZW0476)the LSU - LNNU Joint Research Program (Grant No. 9961)the Foundation of the Education Department of Jiangxi Province (Grant No. [2007]235)the Liaoning Education Department Fund (Grant No. 20060464)
文摘High spin states of 84Sr were populated through the reaction 70Zn(18O,4n)84Sr at 75 MeV beam energy.Measurement of excitation function,γ-γ coincidences,directional correlation from oriented state (DCO) ratios and γ-transition intensities were performed using eight anticompton HPGe detectors and one planar HPGe detector.Based on the measured results,a new level scheme of 84Sr was established in which 12 new states and nearly 30 new γ-transitions were identified in the present work.The positive-parity states of the new level scheme were compared with the results from calculations in the framework of the projected shell model (PSM).One negative-parity band was extended to spin Iπ=19-and it can be found that in the high spin states,the γ-transition energies show the nature of signature staggering.The negative-parity band levels are in good agreement with deformed configuration-mixing shell model (DCM) calculations.
基金Supported by National Natural Science Foundation of China(10505025,10475097)Chinese Academy of Sciences
文摘The level structure of ^19Opt has been studied experimentally using the ^176yb （^18O, 4n） reaction at beam energies of 88 and 95 MeV. γ-γ-t coincidence measurements were carried out. Based on the analysis of T-T coincidence relationships, the level scheme of ^190Pt is extended to high-spin states. A new structure built on the 3413.6 keV 14＋ state has been observed, and the ＂vi13/2^-2 vh9/2^-1 vj （j = P3/2 or f5/2） configuration is tentatively assigned to it.
