A systematic method is developed to studY the classical motion of a mass point in gravitational gauge field. First, by using Mathematica, a spherical symmetric solution of the field equation of gravitational gauge fie...A systematic method is developed to studY the classical motion of a mass point in gravitational gauge field. First, by using Mathematica, a spherical symmetric solution of the field equation of gravitational gauge field is obtained, which is just the traditional Schwarzschild solution. Combining the principle of gauge covariance and Newton＇s second law of motion, the equation of motion of a mass point in gravitational field is deduced. Based on the spherical symmetric solution of the field equation and the equation of motion of a mass point in gravitational field, we can discuss classical tests of gauge theory of gravity, including the deflection of light by the sun, the precession of the perihelia of the orbits of the inner planets and the time delay of radar echoes passing the sun. It is found that the theoretical predictions of these classical tests given by gauge theory of gravity are completely the same as those given by general relativity.展开更多
In general relativity, the equation of motion of the spin is given by the equation of parallel transport, which is a result of the space-time geometry. Any result of the space-time geometry cannog be directly applied ...In general relativity, the equation of motion of the spin is given by the equation of parallel transport, which is a result of the space-time geometry. Any result of the space-time geometry cannog be directly applied to gauge theory of gravity. In gauge theory of gravity, based on the viewpoint of the coupling between the spin and gravitational field, an equation of motlon of the spin is deduced. In the post Newtonian approximation, it is proved that this equation gives the same result as that of the equation of parallel transport. So, in the post Newtonian approximation, gauge theory of gravity gives out the same prediction on the precession of orbiting gyroscope as that of general relativity.展开更多
Background:The recently developed Depression,Anxiety,and Stress Scales–Youth Version(DASS-Y)shows promise as a tool for assessing youth mental health,but its consistency across timepoints and diverse ages remains und...Background:The recently developed Depression,Anxiety,and Stress Scales–Youth Version(DASS-Y)shows promise as a tool for assessing youth mental health,but its consistency across timepoints and diverse ages remains underexplored.The present study evaluated whether the DASS-Y reliably measured depression,anxiety,and stress among school-aged youth(aged 9–18 years)across distinct time periods and educational stages.Methods:Two studies were conducted.Study 1 examined consistency over three months using data from 736 Central Chinese high school students who completed surveys at both timepoints.Study 2 tested consistency across educational levels among 2321 primary and 1676 middle school students.Traditional confirmatory factor analysis(CFA),exploratory structural equation modeling(ESEM),and Rasch analysis were employed to assess the scale’s construct validity and measurement invariance.Results:Rasch analysis indicated acceptable DASS-Y item fit(infit/outfit statistics=0.50–1.50)and moderate test-retest reliability(ICCs=0.64–0.69).The ESEM approach demonstrated superior model fit compared to CFA,achieving a good RMSEA(0.056–0.062)and lower latent factor correlations(r=0.40–0.60),supporting longitudinal scalar invariance.Across educational levels,measurement invariance was supported,with only a small number of items exhibiting differential item functioning(DIF).Conclusion:The present study demonstrates that the DASS-Y is a reliable tool for assessing emotional health among non-clinical school-aged youth,offering educators a validated measure to monitor psychological well-being across developmental stages and time,thereby informing strategies to support youth mental health in community and educational settings.Future research among clinical populations is needed to extend its utility for diagnostic purposes.展开更多
Objective： To evaluate a scale of patient-reported outcomes for the assessment of myasthenia gravis patients （MG-PRO） in China. Methods： A total of 100 MG patients were interviewed for the field testing. Another 5...Objective： To evaluate a scale of patient-reported outcomes for the assessment of myasthenia gravis patients （MG-PRO） in China. Methods： A total of 100 MG patients were interviewed for the field testing. Another 56 MG patients were selected and assessed with the MG-PRO scale before treatment and at 1, 2 and 4 weeks after treatment. The classical test theory and item response theory （IRT） were used to assess the psychometric characteristics of the MG-PRO scale, Results： The MG-PRO scale included 4 dimensions： physical, psychological, social environment, and treatment. Confirmatory factor analysis showed that each dimension was consistent with the theoretical construct. The scores of the physical and psychological dimensions increased significantly at 1 week after treatment （P〈0.05）. All the dimension scores and the MG-PRO score increased significantly at 2 and 4 weeks after treatment （P〈0.05）. IRT showed that person separation indices were greater than 0.8, most of the item fit residual statistics were within ＋ 2.5, and no item had uniform or non-uniform differential item functioning （DIF） between gender and age （〈40, 〉140）. Conclusions： The MG-PRO scale is valid for measuring the quality of life （QOL） of MG patients, with good reliability, validity, responsiveness, and good psychometric characteristics from IRT. It can be applied to evaluate the QOL of MG patients and to assess treatment effects in clinical trials.展开更多
文摘A systematic method is developed to studY the classical motion of a mass point in gravitational gauge field. First, by using Mathematica, a spherical symmetric solution of the field equation of gravitational gauge field is obtained, which is just the traditional Schwarzschild solution. Combining the principle of gauge covariance and Newton＇s second law of motion, the equation of motion of a mass point in gravitational field is deduced. Based on the spherical symmetric solution of the field equation and the equation of motion of a mass point in gravitational field, we can discuss classical tests of gauge theory of gravity, including the deflection of light by the sun, the precession of the perihelia of the orbits of the inner planets and the time delay of radar echoes passing the sun. It is found that the theoretical predictions of these classical tests given by gauge theory of gravity are completely the same as those given by general relativity.
文摘In general relativity, the equation of motion of the spin is given by the equation of parallel transport, which is a result of the space-time geometry. Any result of the space-time geometry cannog be directly applied to gauge theory of gravity. In gauge theory of gravity, based on the viewpoint of the coupling between the spin and gravitational field, an equation of motlon of the spin is deduced. In the post Newtonian approximation, it is proved that this equation gives the same result as that of the equation of parallel transport. So, in the post Newtonian approximation, gauge theory of gravity gives out the same prediction on the precession of orbiting gyroscope as that of general relativity.
基金supported by a special grant from the Taishan Scholars Project(Project No.tsqn202211130).
文摘Background:The recently developed Depression,Anxiety,and Stress Scales–Youth Version(DASS-Y)shows promise as a tool for assessing youth mental health,but its consistency across timepoints and diverse ages remains underexplored.The present study evaluated whether the DASS-Y reliably measured depression,anxiety,and stress among school-aged youth(aged 9–18 years)across distinct time periods and educational stages.Methods:Two studies were conducted.Study 1 examined consistency over three months using data from 736 Central Chinese high school students who completed surveys at both timepoints.Study 2 tested consistency across educational levels among 2321 primary and 1676 middle school students.Traditional confirmatory factor analysis(CFA),exploratory structural equation modeling(ESEM),and Rasch analysis were employed to assess the scale’s construct validity and measurement invariance.Results:Rasch analysis indicated acceptable DASS-Y item fit(infit/outfit statistics=0.50–1.50)and moderate test-retest reliability(ICCs=0.64–0.69).The ESEM approach demonstrated superior model fit compared to CFA,achieving a good RMSEA(0.056–0.062)and lower latent factor correlations(r=0.40–0.60),supporting longitudinal scalar invariance.Across educational levels,measurement invariance was supported,with only a small number of items exhibiting differential item functioning(DIF).Conclusion:The present study demonstrates that the DASS-Y is a reliable tool for assessing emotional health among non-clinical school-aged youth,offering educators a validated measure to monitor psychological well-being across developmental stages and time,thereby informing strategies to support youth mental health in community and educational settings.Future research among clinical populations is needed to extend its utility for diagnostic purposes.
基金Supported by the Major State Basic Research Development Program of China(973 Program,No.2005CB523500)the Key Project of the National 11th Five Year Research Program of China(No.2006BAI04A12)
文摘Objective： To evaluate a scale of patient-reported outcomes for the assessment of myasthenia gravis patients （MG-PRO） in China. Methods： A total of 100 MG patients were interviewed for the field testing. Another 56 MG patients were selected and assessed with the MG-PRO scale before treatment and at 1, 2 and 4 weeks after treatment. The classical test theory and item response theory （IRT） were used to assess the psychometric characteristics of the MG-PRO scale, Results： The MG-PRO scale included 4 dimensions： physical, psychological, social environment, and treatment. Confirmatory factor analysis showed that each dimension was consistent with the theoretical construct. The scores of the physical and psychological dimensions increased significantly at 1 week after treatment （P〈0.05）. All the dimension scores and the MG-PRO score increased significantly at 2 and 4 weeks after treatment （P〈0.05）. IRT showed that person separation indices were greater than 0.8, most of the item fit residual statistics were within ＋ 2.5, and no item had uniform or non-uniform differential item functioning （DIF） between gender and age （〈40, 〉140）. Conclusions： The MG-PRO scale is valid for measuring the quality of life （QOL） of MG patients, with good reliability, validity, responsiveness, and good psychometric characteristics from IRT. It can be applied to evaluate the QOL of MG patients and to assess treatment effects in clinical trials.
