VR/AR技术作为一种崭新的教育手段,具有很高的潜力来改变中学生传统学习的方式。现如今,我国也在大力推动教育信息化建设,教育部明确将VR技术纳入教育信息化的重点工作。本研究通过实证研究法、实验研究法、问卷调查法对东兴中学高二年...VR/AR技术作为一种崭新的教育手段,具有很高的潜力来改变中学生传统学习的方式。现如今,我国也在大力推动教育信息化建设,教育部明确将VR技术纳入教育信息化的重点工作。本研究通过实证研究法、实验研究法、问卷调查法对东兴中学高二年级地理教学VR/AR应用情况进行调查分析,并在东兴中学高二年级物生地1班实施VR/AR技术辅助教学,发现VR/AR技术应用于地理教学有提升学生的学习动机和兴趣,改善学习成绩,提高地理素养的效果,对此提出运用VR/AR技术的教学内容设计策略、教学环境布置策略及教学资源准备策略。本研究为中学地理教学中实施VR/AR技术提供了有益的研究案例,对未来的相关研究具有一定的参考价值。As a brand-new educational method, VR/AR technology has high potential to change the traditional learning method of middle school students. Nowadays, China is also vigorously promoting the construction of education informatization, and the Ministry of Education has clearly included VR technology in the key work of education informatization. This study investigates and analyzes the application of VR/AR in the second-year geography teaching of Dongxing Middle School through empirical research method, experimental research method and questionnaire survey method, and implements VR/AR technology auxiliary teaching in Class 1 of the second year of Dongxing Middle School. It is found that the application of VR/AR technology in geography teaching has been improved. Students’ learning motivation and interests improve academic performance and improve the effect of geographical literacy. In this regard, the teaching content design strategy, teaching environment layout strategy and teaching resource preparation strategy using VR/AR technology are proposed. This research provides a useful research case for the implementation of VR/AR technology in middle school geography teaching, and has a certain reference value for future relevant research.展开更多
We consider constraints on purely kinetic k-essence models from the latest observational data （including 182 gold SNIa data, the shift parameter, and the acoustic scale）. We find the best-fit values of the parameter...We consider constraints on purely kinetic k-essence models from the latest observational data （including 182 gold SNIa data, the shift parameter, and the acoustic scale）. We find the best-fit values of the parameters are Ωm = 0.37 ± 0.01 and ko = 0.064 ± 0.013 at 68.3% confidence level The phase transition from deceleration to acceleration is found to occur at redshift zq=o - 0.48-0.52 in 68.3% confidence level limits. By applying modelcomparison statistics （F-test, AICc, and BIC）, we find that the purely kinetic k-essence scenario is favored over the ACDM model by the combined data. These results are aJso confirmed by combined data 307 SNIa＋R ＋ la.展开更多
Purely kinetic k-essence models in which the Lagrangian contains only a kinetic factor and does not depend explicitly on the field itself are considered, and a theoretical constraint is obtained： Fx -= F0a^-3. Under ...Purely kinetic k-essence models in which the Lagrangian contains only a kinetic factor and does not depend explicitly on the field itself are considered, and a theoretical constraint is obtained： Fx -= F0a^-3. Under this theoretical constraint, we discuss a kind of purely κ-essence with form F（X） = -（1 ＋ 2X^n）^1/2n, which can be considered as the generalized tachyon field, and find that this kind of κ-essence is not likely a candidate of dark energy to describe the present accelerated expansion of the Universe. This is contrary to a previous suggestion that κ-essence with such a form may be used to describe phantom cosmologies.展开更多
We restrict purely kinetic k-essence.Assuming that the equation of state is a power law of the kinetic energy,i.e.w=w0Xα,we find thatαmust be positive to obtain accelerated phases,constrained from the conditions for...We restrict purely kinetic k-essence.Assuming that the equation of state is a power law of the kinetic energy,i.e.w=w0Xα,we find thatαmust be positive to obtain accelerated phases,constrained from the conditions for stability and causality.In this case the k-essence behaves like a phantom.We also study the evolutions of the equation of state and the speed of sound with numerical simulations.展开更多
We formulate and solve the problem of spherically symmetric, steady state, adiabatic accretion onto a Schwarzschild-like black hole obtained recently. We derive the general analytic expressions for the critical points...We formulate and solve the problem of spherically symmetric, steady state, adiabatic accretion onto a Schwarzschild-like black hole obtained recently. We derive the general analytic expressions for the critical points, the critical velocity, the critical speed of sound, and subsequently the mass accretion rate. The case for polytropic gas is discussed in detail. We find the parameter characterizing the breaking of Lorentz symmetry will slow down the mass accretion rate, while has no effect on the gas compression and the temperature profile below the critical radius and at the event horizon.展开更多
Asymptotically safe gravity is an effective approach to quantum gravity.It is important to differentiate modified gravity,which is inspired by asymptotically safe gravity.In this study,we examine particle dynamics nea...Asymptotically safe gravity is an effective approach to quantum gravity.It is important to differentiate modified gravity,which is inspired by asymptotically safe gravity.In this study,we examine particle dynamics near the improved version of a Schwarzschild black hole.We assume that in the context of an asymptotically safe gravity scenario,the ambient matter surrounding the black hole is of isothermal nature,and we investigate the spherical accretion of matter by deriving solutions at critical points.The analysis of various values of the state parameter for isothermal test fluids,viz.,k=1,1/2,1/3,1/4 show the possibility of accretion onto an asymptotically safe black hole.We formulate the accretion problem as Hamiltonian dynamical system and explain its phase flow in detail,which reveals interesting results in the asymptotically safe gravity theory.展开更多
文摘VR/AR技术作为一种崭新的教育手段,具有很高的潜力来改变中学生传统学习的方式。现如今,我国也在大力推动教育信息化建设,教育部明确将VR技术纳入教育信息化的重点工作。本研究通过实证研究法、实验研究法、问卷调查法对东兴中学高二年级地理教学VR/AR应用情况进行调查分析,并在东兴中学高二年级物生地1班实施VR/AR技术辅助教学,发现VR/AR技术应用于地理教学有提升学生的学习动机和兴趣,改善学习成绩,提高地理素养的效果,对此提出运用VR/AR技术的教学内容设计策略、教学环境布置策略及教学资源准备策略。本研究为中学地理教学中实施VR/AR技术提供了有益的研究案例,对未来的相关研究具有一定的参考价值。As a brand-new educational method, VR/AR technology has high potential to change the traditional learning method of middle school students. Nowadays, China is also vigorously promoting the construction of education informatization, and the Ministry of Education has clearly included VR technology in the key work of education informatization. This study investigates and analyzes the application of VR/AR in the second-year geography teaching of Dongxing Middle School through empirical research method, experimental research method and questionnaire survey method, and implements VR/AR technology auxiliary teaching in Class 1 of the second year of Dongxing Middle School. It is found that the application of VR/AR technology in geography teaching has been improved. Students’ learning motivation and interests improve academic performance and improve the effect of geographical literacy. In this regard, the teaching content design strategy, teaching environment layout strategy and teaching resource preparation strategy using VR/AR technology are proposed. This research provides a useful research case for the implementation of VR/AR technology in middle school geography teaching, and has a certain reference value for future relevant research.
基金Supported by the Directional Research Project of the Chinese Academy of Sciences under Grant No KJCX2-YW-T03, the National Natured Science Foundation of China under Grant Nos 10821061, 10733010, 10725313 and 10847117, and the National Basic Research Program of China under Grant No 2009CB824800.
文摘We consider constraints on purely kinetic k-essence models from the latest observational data （including 182 gold SNIa data, the shift parameter, and the acoustic scale）. We find the best-fit values of the parameters are Ωm = 0.37 ± 0.01 and ko = 0.064 ± 0.013 at 68.3% confidence level The phase transition from deceleration to acceleration is found to occur at redshift zq=o - 0.48-0.52 in 68.3% confidence level limits. By applying modelcomparison statistics （F-test, AICc, and BIC）, we find that the purely kinetic k-essence scenario is favored over the ACDM model by the combined data. These results are aJso confirmed by combined data 307 SNIa＋R ＋ la.
基金Supported in part by the Ministry of Education of China, the Directional Research Project of the Chinese Academy of Sciences under Grant No KJCX2-YW-T03, and the National Natural Science Foundation of China under Grant Nos 10521001, 10733010 and 10725313. We thank Chang-Jun Gao, Pu-Xun Wu, Hao Wei, Yan Wu, Wei-Ke Xiao, Jian-Feng Zhou, Zhi-Xing Ling, and Bi-Zhu Jiang for discussions.
文摘Purely kinetic k-essence models in which the Lagrangian contains only a kinetic factor and does not depend explicitly on the field itself are considered, and a theoretical constraint is obtained： Fx -= F0a^-3. Under this theoretical constraint, we discuss a kind of purely κ-essence with form F（X） = -（1 ＋ 2X^n）^1/2n, which can be considered as the generalized tachyon field, and find that this kind of κ-essence is not likely a candidate of dark energy to describe the present accelerated expansion of the Universe. This is contrary to a previous suggestion that κ-essence with such a form may be used to describe phantom cosmologies.
基金Supported in part by the Natural Science Foundation of Hebei Province under Grant No.A2011201147the Research Fund for Doctoral Programs of Hebei University under Grant No.2009-155the Open Research Topics Fund of Key Laboratory of Particle Astrophysics,Institute of High Energy Physics,Chinese Academy of Sciences,under Grant No.0529410T41-200901.
文摘We restrict purely kinetic k-essence.Assuming that the equation of state is a power law of the kinetic energy,i.e.w=w0Xα,we find thatαmust be positive to obtain accelerated phases,constrained from the conditions for stability and causality.In this case the k-essence behaves like a phantom.We also study the evolutions of the equation of state and the speed of sound with numerical simulations.
基金Supported by National Natural Science Foundation of China under Grant No.11273010the Hebei Provincial Outstanding Youth Fund under Grant No.A2014201068+1 种基金the Outstanding Youth Fund of Hebei University under Grant No.2012JQ02the Midwest Universities Comprehensive Strength Promotion Project
文摘We formulate and solve the problem of spherically symmetric, steady state, adiabatic accretion onto a Schwarzschild-like black hole obtained recently. We derive the general analytic expressions for the critical points, the critical velocity, the critical speed of sound, and subsequently the mass accretion rate. The case for polytropic gas is discussed in detail. We find the parameter characterizing the breaking of Lorentz symmetry will slow down the mass accretion rate, while has no effect on the gas compression and the temperature profile below the critical radius and at the event horizon.
基金Supported in part by Hebei Provincial Natural Science Foundation of China(A2014201068)。
文摘Asymptotically safe gravity is an effective approach to quantum gravity.It is important to differentiate modified gravity,which is inspired by asymptotically safe gravity.In this study,we examine particle dynamics near the improved version of a Schwarzschild black hole.We assume that in the context of an asymptotically safe gravity scenario,the ambient matter surrounding the black hole is of isothermal nature,and we investigate the spherical accretion of matter by deriving solutions at critical points.The analysis of various values of the state parameter for isothermal test fluids,viz.,k=1,1/2,1/3,1/4 show the possibility of accretion onto an asymptotically safe black hole.We formulate the accretion problem as Hamiltonian dynamical system and explain its phase flow in detail,which reveals interesting results in the asymptotically safe gravity theory.
