The nature of bonding in the title compound has been studed by using CASSCF techniques.The ground state of PtN is found to be(2)Pi state arising primarily from:1 sigma(2)2 sigma(2)1 pi(4)1 delta(4)3 sigma(2)2 pi(1)con...The nature of bonding in the title compound has been studed by using CASSCF techniques.The ground state of PtN is found to be(2)Pi state arising primarily from:1 sigma(2)2 sigma(2)1 pi(4)1 delta(4)3 sigma(2)2 pi(1)configuration,which forms triple bond between Pt and N atoms tone sigma,two pi).The lowest quartet state is(4)Sigma(-)State which has the configuration:...1 sigma(2)2 sigma(2)1 pi(4)1 delta(4)3 sigma(1)2 pi(2)and lies higher than the ground state by 0.43eV.展开更多
In this work,we propose the possible assignment of the newly observed X(2239),as well asη(2225),as a molecular state from the interaction of a baryonΛand an antibaryonΛ.With the help of effective Lagrangians,theΛ...In this work,we propose the possible assignment of the newly observed X(2239),as well asη(2225),as a molecular state from the interaction of a baryonΛand an antibaryonΛ.With the help of effective Lagrangians,theΛΛinteraction is described within the one-boson-exchange model withη,η′,ω,ϕ,andσexchanges considered.After inserting the potential kernel into the quasipotential Bethe-Salpeter equation,the bound states from theΛΛinteraction can be studied by searching for the pole of the scattering amplitude.Two loosely bound states with spin parities I^(G)(J^(PC))=0^(+)(0^(−+))and 0^(−)(1^(−−))appear near the threshold with almost the same parameter.The 0^(−)(1^(−−))state can be assigned to X(2239)observed at BESⅢ,which is very close to theΛΛthreshold.The scalar mesonη(2225)can be interpreted as a 0^(+)(0^(−+))state from theΛΛinteraction.The annihilation effect is also discussed through a coupled-channel calculation plus a phenomenological optical potential.It provides large widths to two bound states produced from theΛΛinteraction.The mass of the 1^(−)state is slightly larger than the mass of the 0^(−)state after including the annihilation effect,which is consistent with our assignment of these two states as X(2239)andη(2225),respectively.The results suggest that further investigation is required to understand the structures near theΛΛthreshold,such as X(2239),η(2225),and X(2175).展开更多
文摘本文采用Stillinger-Weber势函数,对液态锗的快速凝固过程进行了分子动力学模拟,运用均方位移(mean square displacement,MSD),对相关函数(pair correlation function PCF),配位数(coordination number)和Wendt-Abraham关系式分析锗快速凝固过程中微观结构的变化。模拟得到液态锗的对相关函数和实验基本一致,说明Stillinger-Weber势准确反映了锗原子之间的受力情况,Stillinger-Weber势模拟锗的熔点在2100 K左右。冷却过程中,对相关函数第一峰随温度的降低而逐渐变尖锐,第二峰逐渐分裂为前低后高的两个次峰,由此表明快速凝固过程中得到的是非晶态锗。模拟结果表明,锗凝固的温度范围是1200-600 K,玻璃转化温度Tg为646 K.
文摘The nature of bonding in the title compound has been studed by using CASSCF techniques.The ground state of PtN is found to be(2)Pi state arising primarily from:1 sigma(2)2 sigma(2)1 pi(4)1 delta(4)3 sigma(2)2 pi(1)configuration,which forms triple bond between Pt and N atoms tone sigma,two pi).The lowest quartet state is(4)Sigma(-)State which has the configuration:...1 sigma(2)2 sigma(2)1 pi(4)1 delta(4)3 sigma(1)2 pi(2)and lies higher than the ground state by 0.43eV.
基金Supported by the National Natural Science Foundation of China(11675228,11775050,61871124)the Fundamental Research Funds for the Central Universities,the national defense Pre-Research foundation of China,by State Key Laboratory of Acoustics,Chinese Academy of Sciences(SKLA201604)Science and Technology on Sonar Laboratory,the Stable Supporting Fund of Acoustic Science and Technology Laboratory。
文摘In this work,we propose the possible assignment of the newly observed X(2239),as well asη(2225),as a molecular state from the interaction of a baryonΛand an antibaryonΛ.With the help of effective Lagrangians,theΛΛinteraction is described within the one-boson-exchange model withη,η′,ω,ϕ,andσexchanges considered.After inserting the potential kernel into the quasipotential Bethe-Salpeter equation,the bound states from theΛΛinteraction can be studied by searching for the pole of the scattering amplitude.Two loosely bound states with spin parities I^(G)(J^(PC))=0^(+)(0^(−+))and 0^(−)(1^(−−))appear near the threshold with almost the same parameter.The 0^(−)(1^(−−))state can be assigned to X(2239)observed at BESⅢ,which is very close to theΛΛthreshold.The scalar mesonη(2225)can be interpreted as a 0^(+)(0^(−+))state from theΛΛinteraction.The annihilation effect is also discussed through a coupled-channel calculation plus a phenomenological optical potential.It provides large widths to two bound states produced from theΛΛinteraction.The mass of the 1^(−)state is slightly larger than the mass of the 0^(−)state after including the annihilation effect,which is consistent with our assignment of these two states as X(2239)andη(2225),respectively.The results suggest that further investigation is required to understand the structures near theΛΛthreshold,such as X(2239),η(2225),and X(2175).
