In this paper, collective excitations in the boson-fermion model are investigated by means of functional integration method. The equations of energy gap and excitation spectrum are derived. Moreover, the Bose energy s...In this paper, collective excitations in the boson-fermion model are investigated by means of functional integration method. The equations of energy gap and excitation spectrum are derived. Moreover, the Bose energy spectrum of zero wave vector Fermi fields is also calculated.展开更多
We propose QCD inspired model to calculate ^-pp and pp elastic scatterings at high energies in this paper. A calculation for total cross section of ^-pp and pp is performed in which the contributions from gluon-gluon,...We propose QCD inspired model to calculate ^-pp and pp elastic scatterings at high energies in this paper. A calculation for total cross section of ^-pp and pp is performed in which the contributions from gluon-gluon, quark-quark, and gluon-quark interactions are included. Our results show that the QCD inspired model gives a perfect fit to experimental data of total cross section both for ^-pp and pp elastic scatterings at the whole energy region where experimental data existed at FNAL and CERN.展开更多
As a pivotal element within the modern service industry,tourism possesses the capacity to reconfigure regional economic dynamics,alter resource flow patterns,and notably influence urban green development.By establishi...As a pivotal element within the modern service industry,tourism possesses the capacity to reconfigure regional economic dynamics,alter resource flow patterns,and notably influence urban green development.By establishing an evaluation index system for urban green development across 60 prefecture-level cities within the Yellow River Basin from 2006 to 2021,this study employs the spatial Durbin model to delve into the nonlinear relationship between the tourism economy and urban green development.Furthermore,it investigates the heterogeneous impact of the tourism economy on green development across varying levels of urbanization.This study reveals several key findings:(1)Both tourism economy and urban green development exhibit significant spatial clustering,with tourism economy showing“midstream>downstream>upstream”and urban green development showing“downstream>midstream>upstream”.(2)The tourism economy exerts a non-linear positive influence on the green development of cities,characterized by a non-linear inverted“S”shape in its direct impact and a nonlinear“S”shape in its indirect impact.(3)As urbanization rate level escalate,the positive influence of the tourism economy on urban green development follows a non-linear trajectory,initially declining before ascending.Specifically,when the urbanization rate level is below the first threshold value,the tourism economy notably promotes urban green development.However,between the first and second threshold values,this positive impact diminishes,only to rebound beyond the second threshold value.展开更多
With the rapid development of the marine economy,the demand for marine resources development and the pressure on marine environmental protection are gradually increasing.It is critical to evaluate and analyze the driv...With the rapid development of the marine economy,the demand for marine resources development and the pressure on marine environmental protection are gradually increasing.It is critical to evaluate and analyze the driving forces of marine sustainable development in order to promote the coordinated development of the marine economy,resources and environment.Taking Jiangsu Province of China as an example,this paper constructs an evaluation index system for marine sustainable development from the three aspects of marine economy,resources and environment,and calculates the weight of the variation coefficient for each indicator.Based on the grey relational model,the average value of the relational degree,calculated by the average value method of correlation coefficients and the weighting method,is then used to evaluate the status of marine sustainable development in this province.The comprehensive index model is used to analyze the dynamic trend of the evolution of marine sustainable development.The driving forces of marine sustainable development are analyzed by the path analysis method combined with the average values of the grey relational degree for each indicator.This analysis found that the marine sustainable development in 2016 and 2012 was good,the situation in 2007 was bad,and the remaining years were intermediate.Compared with the previous years,the optimal conditions of 2008 and 2012 were obvious.The main driving factors of marine sustainable development are cargo throughput of coastal ports,economic losses caused by storm surges in coastal areas,the area of marine nature reserves in coastal areas,coastal wind power generation capacity,and marine biodiversity.展开更多
Green development is an important way to achieve global sustainable development goals, and has become one of the main research hotspots in recent years. Balancing economic development and environmental protection has ...Green development is an important way to achieve global sustainable development goals, and has become one of the main research hotspots in recent years. Balancing economic development and environmental protection has turned out to be a great challenge in Beijing, the capital of China, which can provide some suggestions on ecological civilization construction and green development for other cities. However, there have been limited studies on this crucial topic. Therefore, based on the statistical data for Beijing from 2006 to 2016, this paper constructed the green development evaluation system of Beijing, and used the Projection Pursuit Model and spatial analysis method to analyze the spatial and temporal changes in its green development level. We also aimed to further explore the influences of key factors on green development. Our results illustrated that:(1) the overall and average levels of green development in Beijing showed significant increasing trends;(2) there are obvious spatial differences in green development among districts in Beijing, with the outer districts showing higher values;and(3) the environmental condition and human consumption were two important factors driving the green development in Beijing.展开更多
基金The project supported by the Science Foundation of Sichuan Normal University
文摘In this paper, collective excitations in the boson-fermion model are investigated by means of functional integration method. The equations of energy gap and excitation spectrum are derived. Moreover, the Bose energy spectrum of zero wave vector Fermi fields is also calculated.
基金The project supported in part by National Natural Science Foundation of China under Grant Nos. 10647002 and 10565001 and the Science Foundation of Guangxi Province of China under Grant Nos. 0481030, 0542042, and 0575020
文摘We propose QCD inspired model to calculate ^-pp and pp elastic scatterings at high energies in this paper. A calculation for total cross section of ^-pp and pp is performed in which the contributions from gluon-gluon, quark-quark, and gluon-quark interactions are included. Our results show that the QCD inspired model gives a perfect fit to experimental data of total cross section both for ^-pp and pp elastic scatterings at the whole energy region where experimental data existed at FNAL and CERN.
基金The National Social Science Foundation of China(20BJL103,23BTJ001)The National Natural Science Foundation of China(71934001)+1 种基金The Philosophy and Social Science Foundation of Anhui Province(AHSKZ2022D16)The Project of Graduate Student Research InnovationFund of Anhui University of Finance and Economics(ACYC2022155).
文摘As a pivotal element within the modern service industry,tourism possesses the capacity to reconfigure regional economic dynamics,alter resource flow patterns,and notably influence urban green development.By establishing an evaluation index system for urban green development across 60 prefecture-level cities within the Yellow River Basin from 2006 to 2021,this study employs the spatial Durbin model to delve into the nonlinear relationship between the tourism economy and urban green development.Furthermore,it investigates the heterogeneous impact of the tourism economy on green development across varying levels of urbanization.This study reveals several key findings:(1)Both tourism economy and urban green development exhibit significant spatial clustering,with tourism economy showing“midstream>downstream>upstream”and urban green development showing“downstream>midstream>upstream”.(2)The tourism economy exerts a non-linear positive influence on the green development of cities,characterized by a non-linear inverted“S”shape in its direct impact and a nonlinear“S”shape in its indirect impact.(3)As urbanization rate level escalate,the positive influence of the tourism economy on urban green development follows a non-linear trajectory,initially declining before ascending.Specifically,when the urbanization rate level is below the first threshold value,the tourism economy notably promotes urban green development.However,between the first and second threshold values,this positive impact diminishes,only to rebound beyond the second threshold value.
基金Jiangsu Social Science Fund(19GLC013,17GLB003)Open Fund of Key Laboratory of Marine Management Technology of State Oceanic Administration(2015105HX90085)。
文摘With the rapid development of the marine economy,the demand for marine resources development and the pressure on marine environmental protection are gradually increasing.It is critical to evaluate and analyze the driving forces of marine sustainable development in order to promote the coordinated development of the marine economy,resources and environment.Taking Jiangsu Province of China as an example,this paper constructs an evaluation index system for marine sustainable development from the three aspects of marine economy,resources and environment,and calculates the weight of the variation coefficient for each indicator.Based on the grey relational model,the average value of the relational degree,calculated by the average value method of correlation coefficients and the weighting method,is then used to evaluate the status of marine sustainable development in this province.The comprehensive index model is used to analyze the dynamic trend of the evolution of marine sustainable development.The driving forces of marine sustainable development are analyzed by the path analysis method combined with the average values of the grey relational degree for each indicator.This analysis found that the marine sustainable development in 2016 and 2012 was good,the situation in 2007 was bad,and the remaining years were intermediate.Compared with the previous years,the optimal conditions of 2008 and 2012 were obvious.The main driving factors of marine sustainable development are cargo throughput of coastal ports,economic losses caused by storm surges in coastal areas,the area of marine nature reserves in coastal areas,coastal wind power generation capacity,and marine biodiversity.
基金The National Natural Science Foundation of China (41801202, 41911530693)。
文摘Green development is an important way to achieve global sustainable development goals, and has become one of the main research hotspots in recent years. Balancing economic development and environmental protection has turned out to be a great challenge in Beijing, the capital of China, which can provide some suggestions on ecological civilization construction and green development for other cities. However, there have been limited studies on this crucial topic. Therefore, based on the statistical data for Beijing from 2006 to 2016, this paper constructed the green development evaluation system of Beijing, and used the Projection Pursuit Model and spatial analysis method to analyze the spatial and temporal changes in its green development level. We also aimed to further explore the influences of key factors on green development. Our results illustrated that:(1) the overall and average levels of green development in Beijing showed significant increasing trends;(2) there are obvious spatial differences in green development among districts in Beijing, with the outer districts showing higher values;and(3) the environmental condition and human consumption were two important factors driving the green development in Beijing.