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 共查询到20条相似文献,搜索用时 31 毫秒
1.
以高真空多层绝热低温容器为研究对象,利用残余气体分析仪研究冷阴极真空规管、热阴极真空规管以及热阴极真空规管不同放置位置对低温容器真空夹层内残余气体的影响.结果表明:冷阴极真空规管对低温容器真空夹层内残余气体的影响几乎是可以忽略不计的;热阴极真空规管对低温容器真空夹层内残余气体的影响较大,热阴极的灯丝和残余气体之间存在化...  相似文献   

2.
SU(3) gauge field theory is studied in the Coulomb gauge, and the topologically distinct, but gauge equivalent, vacuum configurations are analysed. Considering the gauge transformations of the form U ε U(2) ?SU(3)/U(2), we have obtained a new class of vacuum fields characterized by the topological quantum number η = ±1.  相似文献   

3.
The Aharonov-Bohm effect shows that the vacuum is structured, and that there can exist a finite vector potentialA in the vacuum when the electric field strengthE and magnetic flux densityB are zero. It is shown on this basis that gauge theory produces energy inherent in the vacuum. The latter is considered as the internal space of the gauge theory, containing a field made up of components ofA, to which a local gauge transformation is applied to produce the electromagnetic field tensor, a vacuum charge/current density, and a topological charge g. Local gauge transformation is the result of special relativity and introduces spacetime curvature, which gives rise to an electromagnetic field whose source is a vacuum charge current density made up ofA and g. The field carries energy to a device which can in principle extract energy from the vacuum. The development is given forU(1) andO(3) invariant gauge theory applied to electrodynamics. Former Edward Davies Chemical Laboratories, University College of Wales, Aberystwyth SY32 1NE, Wales, United Kingdom.  相似文献   

4.
We analyze the geometrical structure of the local non-Abelian gauge theory in terms of the magnetic symmetry, using the resemblance between the non-Abelian gauge formulations and Einstein's theory of gravitation in a higher dimensional unified space. The mathematical foundation of dual QCD in fiber bundle form is then discussed and used for the analysis of the important problem of color confinement in QCD. The associated Lagrangian formulation in magnetic gauge is shown to lead to dual dynamics due to the emergence of the topological charges of magnetic nature. The dynamical breaking of magnetic symmetry is shown to lead to the magnetic condensation of the QCD vacuum. A state of the dual superconductivity in the QCD vacuum is then shown to evolve which ultimately pushes the QCD vacuum to the confining phase. The flux tube structure of the magnetically condensed QCD vacuum is analyzed by computing the asymptotic string solutions of the field equations. The energy content of such confining structures is computed and analyzed in terms of its logarithmic and linear nature.  相似文献   

5.
The phase transition of a simple local gauge model is investigated in terms of the Nambu-Jona-Lasinio mechanism and it is pointed out that the physical vacuum of QCD is bound state of quark-antiquark pairs which can be viewed, generally, as a nearly perfect color dia-electric medium. An important relation between the vacuum expectation value of gauge fields and scalar fields is also derived by solving the Euler equation for the gauge fields. Based on this relation the SUC(3) gauge potential is given which can be used to explain the asymptotic behavior and confinement of quarks in a hadron, and at the same time the Yukawa potential of strong interaction can be given too.  相似文献   

6.
介绍了一种基于热学知识设计的表面薄膜微型MEMS皮拉尼计,并将其用于圆片级真空封装腔体的真空度测量中。为了设计灵敏度较高的皮拉尼计,对不同结构的皮拉尼计的热量分布进行了数值计算与分析,并最终完成了加工。此皮拉尼计的结构和加工工艺比较简单,能用于一般的MEMS真空封装中。实验结果显示该皮拉尼计可以测量1-10^5Pa的真...  相似文献   

7.
The vacuum alignment problem is analyzed in the context of supersymmetric gauge theories with dynamical symmetry breaking. Three cases are distinguished, depending on whether the vacuum expectation value of the weak gauge current superfield in vacuum characterized by the orientation Ω is zero for all Ω, for some Ω, or for no Ω. In the first case, a non-renormalization theorem is proved to all orders in the weak coupling, showing that the usual criterion of minimizing the vacuum energy density is insufficient to determine the alignment, and possible resolutions of the problem are discussed. The second case is similar, except that the possible alignments are resricted to the range of Ω giving a vanishing VEV and the weak gauge group may then be broken non-minimally. In the third case, supersymmetry is itself broken at the tree level by the weak interactions. The supersymmetric generalization of the Schwinger mechanism for dynamical mass generation is described.  相似文献   

8.
WU Ning 《理论物理通讯》2002,38(2):151-156
The quantum gravity is formulated based on the principle of local gauge invariance. The model discussed in this paper has local gravitational gauge symmetry, and gravitational field is represented by gauge field. In the leading-order approximation, it gives out classical Newton's theory of gravity. In the first-order approximation and for vacuum, it gives out Einstein's general theory of relativity. This quantum gauge theory of gravity is a renormalizable quantum theory.  相似文献   

9.
The quantum gravity is formulated based on the principle of local gauge invariance. The model discussedin this paper has local gravitational gauge symmetry, and gravitational field is represented by gauge field. In the leading-order approximation, it gives out classical Newton‘s theory of gravity. In the first-order approximation and for vacuum,it gives out Einstein‘s general theory of relativity. This quantum gauge theory of gravity is a renormalizable quantumtheory.  相似文献   

10.
Green functions of on-mass-shell transverse gauge fields in a background gauge are proved to be obtained from Green functions in the perturbative vacuum by a mere translation.  相似文献   

11.
WU Ning 《理论物理通讯》2004,41(4):567-572
In 1992, E.E. Podkletnov and R. Nieminen found that under certain conditions, ceramic superconductor with composite structure reveals weak shielding properties against gravitational force. In classical Newton's theory of gravity and even in Einstein's general theory of gravity, there are no grounds of gravitational shielding effects. But in quantum gauge theory of gravity, the gravitational shielding effects can be explained in a simple and natural way. In quantum gauge theory of gravity, gravitational gauge interactions of complex scalar field can be formulated based on gauge principle. After spontaneous symmetry breaking, if the vacuum of the complex scalar field is not stable and uniform, there will be a mass term of gravitational gauge field. When gravitational gauge field propagates in this unstable vacuum of the complex scalar field, it will decays exponentially, which is the nature of gravitational shielding effects. The mechanism of gravitational shielding effects is studied in this paper, and some main properties of gravitational shielding effects are discussed.  相似文献   

12.
张虎忠  李得天  董长昆  成永军  肖玉华 《物理学报》2013,62(11):110703-110703
本文基于IE514分离规结构, 建立了碳纳米管阴极电离规物理模型, 根据电离规标准方程, 利用离子光学模拟软件SIMION 8.0分别研究了电极电压对灵敏度和Igrid/Ie的影响. 结果表明, 随着阳极/门极电压比值增大(Vgrid/Vgate), Igrid/Ie也将增大, 然而, 当阳极电压增大时, 会导致灵敏度降低, 进而影响真空测量下限的延伸; 该模拟结果与相关文献报道的实验结果符合性很好. 因此, 选择合适的电极电压, 将有利于提高灵敏度, 增大阳极电流, 进一步延伸真空测量下限. 本文所采用的数值模拟方法可推广应用于各种新型碳纳米管阴极极高真空电离规的研发和理论分析中, 为解决极高真空测量难题提供了有效的研究途径. 关键词: 碳纳米管阴极电离规 电极电压 灵敏度 阳极电流  相似文献   

13.
The effective potential for an on-shell BRST invariant gluon-ghost condensate of mass dimension 2 in the Curci-Ferrari gauge in SU(N) Yang-Mills is analysed by combining the local composite operator technique with the algebraic renormalization. We pay attention to the gauge parameter independence of the vacuum energy obtained in the considered framework and discuss the Landau gauge as an interesting special case.  相似文献   

14.
鲁长宏  张瑞  李玉兰 《物理实验》2006,26(11):31-34
介绍了TO-8型压力传感器的性能及电源电路.以气体导热系数测定实验为例,用TO-8型压力传感器制成的测压装置代替旋转式麦氏真空计,利用可调针孔式放气阀对真空气压进行连续调节,实现了对测试系统真空度的实时监测.  相似文献   

15.
《Nuclear Physics B》1988,301(1):93-114
The problem of the origin of the gauge particle's mass is considered in the framework of the BRS symmetry. A new approach is suggested where the global gauge group symmetry of the quantum theory is hidden by the condensation of bound states of the ghost fields in the perturbative vacuum. Dynamical mass generation for the gauge fields follows the Schwinger mechanism.  相似文献   

16.
Klumb-schwarz提出的同轴圆筒形辐射真空计,原则上可以作为低气压的绝对量具,然而由于迄今并未有人提出完整的灵敏度理论,困此限制了它作为绝对量具的可能性。本文叙述一种近似解法,可以得出灵敏度的绝对值,并从理论上决定其最佳几何结构。最后还对这种真空计的量程上下限作了讨论。 关键词:  相似文献   

17.
A gauge theory with gauge potentials that are compatible with right invariant metric of the gauge group is presented. It is shown that in the metric compatible torsion free gauge theory, gauge potentials can acquire the mass, without introducing the tliggs field. A plane-wave exact solution in vacuum is obtained.  相似文献   

18.
薛社生  冼鼎昌 《物理学报》1985,34(8):1084-1087
在U(1)规范场理论中,用Feynman路径积分方法,简明地显示了:(1)鬼粒子对真空能量(Casimir能量)的贡献;(2)不同的协变规范对真空能量的影响。 关键词:  相似文献   

19.
Three gauge invariant antisymmetric tensor fields are introduced in the nonabelian gauge theories. They are certain non-linear combinations of the conjugate field tensor and they obey O(3) algebra. An effective chiral lagrangian for these fields is derived. It describes 3 vector and 3 axial mesons with vacuum quantum numbers. The masses are generated by spontaneous restoration of Lorentz invariance.  相似文献   

20.
We formulate a conformally invariant gauge fixing for Maxwell fields. If the background space-time is vacuum then this gauge is related to but weaker than Lorentz gauge.  相似文献   

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