An experiment was conducted for studying the cluster structure of Be induced by He ions at an energy of 30 MeV.As results of the nuclear reaction^(3)He+^(9)Be,the differential cross sections for the exit channels–ela...An experiment was conducted for studying the cluster structure of Be induced by He ions at an energy of 30 MeV.As results of the nuclear reaction^(3)He+^(9)Be,the differential cross sections for the exit channels–elastic,inelastic,α+^(8)Be,^(6)He+^(6)Be,^(6)Li+^(6)Li,and^(7)Be+^(5)He–were measured.Elastic and inelastic scattering data were treated within both the optical model and coupled channel method.A new set of optical potentials was considered for the elastic scattering.The deformation parameter was established for the transition 3/2→5/2.Cluster transfer reactions were analyzed via the coupled reaction channel method.The nuclear reactions with the exit channels^(6)He+^(6)Be,^(6)Li+^(6)Li,and^(7)Be+^(5)He were complemented by two-step transfer mechanisms.The contribution of each reaction mechanism were shown and compared with the findings of other authors.展开更多
This paper develops a dynamic theoretical framework for global competitiveness, which describes the relationships among organizations in an industry cluster. The spiral for knowledge transfer, culture variables and em...This paper develops a dynamic theoretical framework for global competitiveness, which describes the relationships among organizations in an industry cluster. The spiral for knowledge transfer, culture variables and embeddedness influence knowledge transfer. Embeddedness and knowledge transfer are the key determinants of industry clusters that lead to global competitiveness. Industry clusters are characterized by external economies, generalized reciprocity and flexible specialization.展开更多
轨道交通网络中乘客的出行受网络结构和运营状况变化的影响,个体出行偏好对这些变化的响应也各异。为分析轨道交通远郊区段计划性停运对常乘客的出行转移影响,本文提出考虑转移类型和转移比例的乘客出行特征刻画方法,结合时段属性生成...轨道交通网络中乘客的出行受网络结构和运营状况变化的影响,个体出行偏好对这些变化的响应也各异。为分析轨道交通远郊区段计划性停运对常乘客的出行转移影响,本文提出考虑转移类型和转移比例的乘客出行特征刻画方法,结合时段属性生成乘客特征—时序(FeatureTemporal,F-T)矩阵;通过改进的欧氏距离计算F-T矩阵间的相似性,实现F-T矩阵的相似性度量;提出一种基于相似度矩阵的K-Means聚类和层次聚类相结合的两步聚类方法(Two-step Clustering of K-Means Clustering and Hierarchical Clustering,KMHC)划分乘客影响群体,分析影响乘客出行转移的因素;以新冠肺炎疫情期间上海轨道交通11号线昆山段停运作为实例,对本文方法进行验证。研究结果表明:昆山段停运后,常乘客呈现出5种主要的出行转移影响群体,占常乘客总数的94.4%;各影响群体的转移距离、通勤时间和出行频率差异明显,是影响区段停运后常乘客出行选择的重要因素。本文方法可为其他计划性停运场景提供借鉴和参考,也可为区段停运后的网络客流变化预测,行车和客运组织方案优化提供支撑。展开更多
The steady-state fluorescence spectrum characteristic of ethanol-water excimer has been studied in this paper. By analysing the features of the sharp emission spectrum with fine structures in a shortwave band and the ...The steady-state fluorescence spectrum characteristic of ethanol-water excimer has been studied in this paper. By analysing the features of the sharp emission spectrum with fine structures in a shortwave band and the characteristics of the broad and featureless fluorescence peaks in the longwave band, one can conclude that the excimers are formed between the new ethanol-water cluster molecules in the excited state and the ground state through the interaction among different chromophores. The excitation spectra in the two fluorescence bands have been studied, and their emission mechanisms have been ascertained based on the energy transfer theory. Furthermore, the critical distance of the resonance energy transfer has been calculated.展开更多
The electronic and physical properties of PtmPdn （m＋n≤5） metal clusters and their interactions with dioxygen have been studied by using hybrid density functional B3LYP method. The total energies, atomization energ...The electronic and physical properties of PtmPdn （m＋n≤5） metal clusters and their interactions with dioxygen have been studied by using hybrid density functional B3LYP method. The total energies, atomization energies, vibration frequencies, and charge distributions were reported. The Pt-Pt bridge site modified by Pd atoms was found to be the most active site for the dissociation of dioxygen, which was mainly due to the change of electronic structures of the Pt atoms in bimetallic Pt-Pd clusters.展开更多
Multiphoton ionization (MPI) of the hydrogen-bonded clusters C4H5N-(H2O)(m) was studied with a time of flight (TOF) mass spectrometer at 355 nm. Series of the pyrrole-water cluster ions were observed, including unprot...Multiphoton ionization (MPI) of the hydrogen-bonded clusters C4H5N-(H2O)(m) was studied with a time of flight (TOF) mass spectrometer at 355 nm. Series of the pyrrole-water cluster ions were observed, including unprotonated cluster ions [C4H5N-(H2O)(n)](+), protonated cluster ions [C4H5N-(H2O)(n)H](+) and dehydrogenated cluster ions [C4H4N-(H2O)(n)](+). Both the experimental and ab initio calculated results agree with that the dehydrogenation has more probabilities to occur while the value of n is raised.展开更多
基金Supported by the Science Committee of the Ministry of Science and Higher Education of the Republic of Kazakhstan(AP14870958)。
文摘An experiment was conducted for studying the cluster structure of Be induced by He ions at an energy of 30 MeV.As results of the nuclear reaction^(3)He+^(9)Be,the differential cross sections for the exit channels–elastic,inelastic,α+^(8)Be,^(6)He+^(6)Be,^(6)Li+^(6)Li,and^(7)Be+^(5)He–were measured.Elastic and inelastic scattering data were treated within both the optical model and coupled channel method.A new set of optical potentials was considered for the elastic scattering.The deformation parameter was established for the transition 3/2→5/2.Cluster transfer reactions were analyzed via the coupled reaction channel method.The nuclear reactions with the exit channels^(6)He+^(6)Be,^(6)Li+^(6)Li,and^(7)Be+^(5)He were complemented by two-step transfer mechanisms.The contribution of each reaction mechanism were shown and compared with the findings of other authors.
文摘This paper develops a dynamic theoretical framework for global competitiveness, which describes the relationships among organizations in an industry cluster. The spiral for knowledge transfer, culture variables and embeddedness influence knowledge transfer. Embeddedness and knowledge transfer are the key determinants of industry clusters that lead to global competitiveness. Industry clusters are characterized by external economies, generalized reciprocity and flexible specialization.
文摘轨道交通网络中乘客的出行受网络结构和运营状况变化的影响,个体出行偏好对这些变化的响应也各异。为分析轨道交通远郊区段计划性停运对常乘客的出行转移影响,本文提出考虑转移类型和转移比例的乘客出行特征刻画方法,结合时段属性生成乘客特征—时序(FeatureTemporal,F-T)矩阵;通过改进的欧氏距离计算F-T矩阵间的相似性,实现F-T矩阵的相似性度量;提出一种基于相似度矩阵的K-Means聚类和层次聚类相结合的两步聚类方法(Two-step Clustering of K-Means Clustering and Hierarchical Clustering,KMHC)划分乘客影响群体,分析影响乘客出行转移的因素;以新冠肺炎疫情期间上海轨道交通11号线昆山段停运作为实例,对本文方法进行验证。研究结果表明:昆山段停运后,常乘客呈现出5种主要的出行转移影响群体,占常乘客总数的94.4%;各影响群体的转移距离、通勤时间和出行频率差异明显,是影响区段停运后常乘客出行选择的重要因素。本文方法可为其他计划性停运场景提供借鉴和参考,也可为区段停运后的网络客流变化预测,行车和客运组织方案优化提供支撑。
文摘The steady-state fluorescence spectrum characteristic of ethanol-water excimer has been studied in this paper. By analysing the features of the sharp emission spectrum with fine structures in a shortwave band and the characteristics of the broad and featureless fluorescence peaks in the longwave band, one can conclude that the excimers are formed between the new ethanol-water cluster molecules in the excited state and the ground state through the interaction among different chromophores. The excitation spectra in the two fluorescence bands have been studied, and their emission mechanisms have been ascertained based on the energy transfer theory. Furthermore, the critical distance of the resonance energy transfer has been calculated.
基金This work was partly supported by Innovation Foundation of the Chinese Academy of Sciences (K2003D2), National Natural Science Foundation of China (No. 20173060), Hi-tech Research and Development Program of China (2003AA517040) and Knowledge Innovation Program of the Chinese Academy of Sciences (KGCX2-SW-310)
文摘The electronic and physical properties of PtmPdn （m＋n≤5） metal clusters and their interactions with dioxygen have been studied by using hybrid density functional B3LYP method. The total energies, atomization energies, vibration frequencies, and charge distributions were reported. The Pt-Pt bridge site modified by Pd atoms was found to be the most active site for the dissociation of dioxygen, which was mainly due to the change of electronic structures of the Pt atoms in bimetallic Pt-Pd clusters.
基金the National Natural Science Foundation of China (No.29833080).
文摘Multiphoton ionization (MPI) of the hydrogen-bonded clusters C4H5N-(H2O)(m) was studied with a time of flight (TOF) mass spectrometer at 355 nm. Series of the pyrrole-water cluster ions were observed, including unprotonated cluster ions [C4H5N-(H2O)(n)](+), protonated cluster ions [C4H5N-(H2O)(n)H](+) and dehydrogenated cluster ions [C4H4N-(H2O)(n)](+). Both the experimental and ab initio calculated results agree with that the dehydrogenation has more probabilities to occur while the value of n is raised.
