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论有质粒子作超光速运动的可能性 被引量:4
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作者 黄志洵 《中国传媒大学学报(自然科学版)》 2015年第3期1-16,共16页
狭义相对论(SR)中运动的有质粒子的长度(l)、质量(m)、能量(E或W)随速度v变化。当v增大,l减小而m和E加大。如果v=c,运动粒子的质量、能量成为无限大。故Einstein断言讨论超越光速c是无意义的。然而在实际上从未发现过物体长度随速度增... 狭义相对论(SR)中运动的有质粒子的长度(l)、质量(m)、能量(E或W)随速度v变化。当v增大,l减小而m和E加大。如果v=c,运动粒子的质量、能量成为无限大。故Einstein断言讨论超越光速c是无意义的。然而在实际上从未发现过物体长度随速度增加而减小。对质量而言,Newton力学中质量与速度无关;质量随速度变来自1904年的Lorentz公式m=m0[1-(v2/c)]-1/2,即使它适用于电子也不能像SR那样推广于一切动体,实际上缺少"Lorentz质速公式适用于中性粒子和中性物体"的实验。故所谓"光障"不一定真的存在。电子并不是一个普通的动体,而是特殊的带有电荷的动体。故即使v=c,能量也不是无限大。另外,还可证明当速度v增大时动体荷电量q和受力F都减小。这就很好的解释了1901年的Kaufmann实验。类似地,分析表明1964年的Bertozi实验也不能证明光速c不可超越。本文把今日的"光障"问题与过去的"声障"问题作了比较,认为可压缩流体力学可用在超光速研究中,空气动力学发展对突破光障有参考作用。在超声速飞机问世前,当飞机速度接近声速将形成气体超大密度的激波,飞机将无法穿越它。但深入的理论分析和风洞实验使科学家获悉,即使v=c(在这里c为声速),密度仅增大6倍,不是无限大;故工程师开始设计和建造超声速飞机。1947年10月14日美国空军完成了人类首次超声速飞行。……我们相信对所谓光障也会是同样的情况。由于量子力学中的波粒二象性,科学家可按两条路径(粒子或波)展开研究。过去认为微观客体会呈现为粒子或波,但不会同时体现这两者。然而最新的研究却证明可在实验中又是粒子又是波。本文建议设计针对物质波的实验。由于现时有大量的群速超光速实验已获成功,可以期待超光速有质粒子(电子或质子)的存在和发现。……总之,结论是有质粒子可以作超光速运动,但有待将来的直接实验证明。 展开更多
关键词 有质粒子 光障 超光速运动
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有质粒子在引力场中的偏转
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作者 周晨立 《宝鸡文理学院学报(自然科学版)》 CAS 1993年第2期77-82,共6页
根据广义相对论,讨论了静质量不为零的粒子在球对称场中的偏转,并与牛顿引力理论和狭义相对论的结果对比,指出在高速情况时三种理论预测间的明显差别。
关键词 广义相对论 有质粒子 引力场 偏转
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Time Varying Gravitational Constant G via Entropic Force 被引量:1
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作者 M.R.Setare D.Momeni 《Communications in Theoretical Physics》 SCIE CAS CSCD 2011年第10期691-694,共4页
If the uncertainty principle applies to the Verlinde entropic idea, it leads to a new term in the Newton's second law of mechanics in the Planck's scale. This curious velocity dependent term inspires a frictional fe... If the uncertainty principle applies to the Verlinde entropic idea, it leads to a new term in the Newton's second law of mechanics in the Planck's scale. This curious velocity dependent term inspires a frictional feature of the gravity. In this short letter we address that this new term modifies the effective mass and the Newtonian constant as the time dependent quantities. Thus we must have a running on the value of the effective mass on the particle mass m near the holographic screen and the G. This result has a nigh relation with the Dirac hypothesis about the large numbers hypothesis (L.N.H.). We propose that the corrected entropie terms via Verlinde idea can be brought as a holographic evidence for the authenticity of the Dirac idea. 展开更多
关键词 gravitational constant general relativing
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Measurement of aerosol effective density by single particle mass spectrometry 被引量:2
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作者 ZHANG GuoHua BI XinHui +5 位作者 HAN BingXue QIU Ning DAI ShouHui WANG XinMing SHENG GuoYing FU JiaMo 《Science China Earth Sciences》 SCIE EI CAS CSCD 2016年第2期320-327,共8页
Single particle mass spectrometry has been widely used to determine the size and chemical compositions of at- mospheric aerosols; however, it is still rarely used for the microphysical properties measurement. In this ... Single particle mass spectrometry has been widely used to determine the size and chemical compositions of at- mospheric aerosols; however, it is still rarely used for the microphysical properties measurement. In this study, two methods were developed for determining aerosol effective density by a single particle aerosol mass spectrometer (SPAMS). Method I retrieved effective density through comparison between measured light scattering intensities and Mie theoretical modelled par- tial scattering cross section. Method Ⅱ coupled a differential mobility analyzer (DMA) with SPAMS to simultaneously deter- mine the electric mobility and vacuum aerodynamic diameter, and thus the effective density. Polystyrene latex spheres, ammo- nium sulfate and sodium nitrate were tested by these methods to help validate their effectiveness for determining the aerosol effective density. This study effectively extends SPAMS measurements to include particle size, chemical composition, light scattering, and effective density, and thus helps us better understand the environment and climate effects of aerosols. 展开更多
关键词 Effective density Single particle SPAMS Mie theory DMA
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