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论功及动能变化量的相对性和绝对性 被引量:1
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作者 王小平 《物理教师》 北大核心 2015年第3期91-93,共3页
功、动能、动能的变化量及动能定理不但是高中物理的一个重要内容,也是学生学习的一个难点,特别是动能定理的使用条件不清楚.因此,本文将通过两个具体的物理过程来论述功和动能变化量的相对性与绝对性,并由此理解动能定理和能量守恒定... 功、动能、动能的变化量及动能定理不但是高中物理的一个重要内容,也是学生学习的一个难点,特别是动能定理的使用条件不清楚.因此,本文将通过两个具体的物理过程来论述功和动能变化量的相对性与绝对性,并由此理解动能定理和能量守恒定律的适用范围. 展开更多
关键词 动能变化量 相对性 绝对性 参考系
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稳定流动干绝热递减率的研究
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作者 魏亮 《日用电器》 2015年第8期165-167,共3页
经过分析和推导,发现"干绝热递减率"在实际应用中有一定的局限性。本文在此基础上,根据空气流动的不等速性,运用稳定流动方程重新推导了更具有普适性的干绝热递减率公式,称为稳定流动干绝热递减率。并分析了两个干绝热递减率... 经过分析和推导,发现"干绝热递减率"在实际应用中有一定的局限性。本文在此基础上,根据空气流动的不等速性,运用稳定流动方程重新推导了更具有普适性的干绝热递减率公式,称为稳定流动干绝热递减率。并分析了两个干绝热递减率的区别和联系,有一定的理论意义。 展开更多
关键词 稳定流动 温度梯度 干绝热递减率 动能变化量
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Extended Active Contour Algorithm Based on Color Variance
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作者 Seung-tae LEE Young-jun HAN Hern-soo HAHN 《Journal of Measurement Science and Instrumentation》 CAS 2010年第1期50-53,共4页
General active contour algorithm, which uses the intensity of the image, has been used to actively segment objects. Because the objects have a similar intensity but different colors, it is difficult to segment any obj... General active contour algorithm, which uses the intensity of the image, has been used to actively segment objects. Because the objects have a similar intensity but different colors, it is difficult to segment any object from the others, Moreover, this algodthm can only be used in the simple environment since it is very sensitive to noise. In tinter to solve these problems. This paper proposes an extended active contour algorithm based on a color variance. In complex images, the color variance energy as the image energy is introduced into the general active contour algorithm. Experimental results show that the proposed active contour algorithm is very effective in various environments. 展开更多
关键词 extended active contour algorithm color variance segmentaion method
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Modified Nonlinear Model of Arcsin-Electrodynamics
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作者 S.I.Kruglov 《Communications in Theoretical Physics》 SCIE CAS CSCD 2016年第7期59-65,共7页
A new modified model of nonlinear arcsin-electrodynamics with two parameters is proposed and analyzed.We obtain the corrections to the Coulomb law. The effect of vacuum birefringence takes place when the external cons... A new modified model of nonlinear arcsin-electrodynamics with two parameters is proposed and analyzed.We obtain the corrections to the Coulomb law. The effect of vacuum birefringence takes place when the external constant magnetic field is present. We calculate indices of refraction for two perpendicular polarizations of electromagnetic waves and estimate bounds on the parameter γ from the BMV and PVLAS experiments. It is shown that the electric field of a point-like charge is finite at the origin. We calculate the finite static electric energy of point-like particles and demonstrate that the electron mass can have the pure electromagnetic nature. The symmetrical Belinfante energy-momentum tensor and dilatation current are found. We show that the dilatation symmetry and dual symmetry are broken in the model suggested. We have investigated the gauge covariant quantization of the nonlinear electrodynamics fields as well as the gauge fixing approach based on Dirac's brackets. 展开更多
关键词 vacuum birefringence energy-momentum tensor static electric energy dilatation current dual symmetry quantization Dirac's brackets
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Analysis of Generalized Ghost Dark Energy in LQC and Galileon Gravity
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作者 mahasweta biswas ujjal debnath 《Communications in Theoretical Physics》 SCIE CAS CSCD 2016年第1期121-126,共6页
A so-called ghost dark energy was recently proposed to explain the present acceleration of the universe.The energy density of ghost dark energy,which originates from Veneziano ghost of Quantum Chromodynamics(QCD),in a... A so-called ghost dark energy was recently proposed to explain the present acceleration of the universe.The energy density of ghost dark energy,which originates from Veneziano ghost of Quantum Chromodynamics(QCD),in a time dependent background,can be written in the form,ρD=αH + βH^2 where H is the Hubble parameter.We investigate the generalized ghost dark energy(GGDE) model in the setup of loop quantum Cosmology(LQC) and Galileon Cosmology.We study the cosmological implications of the models.We also obtain the equation of state and the deceleration parameters and differential equations governing the evolution of this dark energy model for LQC and Galileon Cosmology. 展开更多
关键词 ghost dark energy loop equation cosmology Galileon gravity
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