The new members of the charm-strange family Dsj^＊（2317）, Dsj（2460）, and Ds（2632）, which have the surprising properties, are challenging the present models. Many theoretical interpretations have been devoted to ...The new members of the charm-strange family Dsj^＊（2317）, Dsj（2460）, and Ds（2632）, which have the surprising properties, are challenging the present models. Many theoretical interpretations have been devoted to this issue. Most authors suggest that they are not the conventional cs^- quark model states, but possibly are four-quark states, molecule states, or mixtures of a P-wave cs^- and a four-quark state. In this work, we follow the four-quark-state picture, and study the masses of cnn^-s^-/css^-s^- states （n is u or d quark） in the chiral SU（3） quark model. The numerical results show that the mass of the mixed four-quark state （cnn^-s^-/css^-s^-） with spin parity j^P ： 0^＋ might not be Ds （2632）. At the same time, we also conclude that Dsj^＊（2317） and Dsj（2460） cannot be explained as the pure four-quark state.展开更多
在220 k V电压互感器的现场误差试验中,通常存在着调谐升压效率偏低、试验电源容量要求高等问题。基于电压电感多阶导数和功率因数判断的优化算法、开口铁心双向调节改进设计,研究设计了全自动工频谐振升压装置,实现了对220 k V电压互...在220 k V电压互感器的现场误差试验中,通常存在着调谐升压效率偏低、试验电源容量要求高等问题。基于电压电感多阶导数和功率因数判断的优化算法、开口铁心双向调节改进设计,研究设计了全自动工频谐振升压装置,实现了对220 k V电压互感器一次回路的工频全自动谐振升压。现场应用表明,该装置可自动在工频条件下动态调节电感量,准确寻找谐振点实现升压,同时比现有设备更加轻便,满足现场人员组合搬运要求,提高试验效率和安全水平。展开更多
The structures of Ωω states with spin-parity JP= 5/2^-, 3/2^-, and 1/2^- are dynamically studied in both the chlral SU（3） quark model and the extended chiral SU（3） quark model by solving a resonating group meth...The structures of Ωω states with spin-parity JP= 5/2^-, 3/2^-, and 1/2^- are dynamically studied in both the chlral SU（3） quark model and the extended chiral SU（3） quark model by solving a resonating group method （RGM） equation. The model parameters are taken from our previous work, which gave a satisfactory description of the energies of the baryon ground states, the binding energy of the deuteron, the nucleon-nucleon （NN） scattering phase shifts, and the hyperon-nucleon （YN） cross sections. The calculated results show that the Ωω state has an attractive interaction, and in the extended chiral SU（3） quark model such attraction can make for a Ωω quasi-bound state with spin-parity JP = 3/2^- or 5/2^- and the binding energy of about several MeV.展开更多
基金National Natural Science Foundation of China under Grant No 10475087
文摘The new members of the charm-strange family Dsj^＊（2317）, Dsj（2460）, and Ds（2632）, which have the surprising properties, are challenging the present models. Many theoretical interpretations have been devoted to this issue. Most authors suggest that they are not the conventional cs^- quark model states, but possibly are four-quark states, molecule states, or mixtures of a P-wave cs^- and a four-quark state. In this work, we follow the four-quark-state picture, and study the masses of cnn^-s^-/css^-s^- states （n is u or d quark） in the chiral SU（3） quark model. The numerical results show that the mass of the mixed four-quark state （cnn^-s^-/css^-s^-） with spin parity j^P ： 0^＋ might not be Ds （2632）. At the same time, we also conclude that Dsj^＊（2317） and Dsj（2460） cannot be explained as the pure four-quark state.
文摘在220 k V电压互感器的现场误差试验中,通常存在着调谐升压效率偏低、试验电源容量要求高等问题。基于电压电感多阶导数和功率因数判断的优化算法、开口铁心双向调节改进设计,研究设计了全自动工频谐振升压装置,实现了对220 k V电压互感器一次回路的工频全自动谐振升压。现场应用表明,该装置可自动在工频条件下动态调节电感量,准确寻找谐振点实现升压,同时比现有设备更加轻便,满足现场人员组合搬运要求,提高试验效率和安全水平。
基金The project supported in part by National Natural Science Foundation of China under Grant No. 10475087
文摘The structures of Ωω states with spin-parity JP= 5/2^-, 3/2^-, and 1/2^- are dynamically studied in both the chlral SU（3） quark model and the extended chiral SU（3） quark model by solving a resonating group method （RGM） equation. The model parameters are taken from our previous work, which gave a satisfactory description of the energies of the baryon ground states, the binding energy of the deuteron, the nucleon-nucleon （NN） scattering phase shifts, and the hyperon-nucleon （YN） cross sections. The calculated results show that the Ωω state has an attractive interaction, and in the extended chiral SU（3） quark model such attraction can make for a Ωω quasi-bound state with spin-parity JP = 3/2^- or 5/2^- and the binding energy of about several MeV.
