首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 484 毫秒
1.
2.
Based on a theory of primitive particles presented in two earlier papers, further applications to macro- and microphenomena are considered—for example, weather phenomena, earthquakes, photoemission, collision of particles, violation of parity, and decay modes. A broad class of leptons withSU(3) symmetry is proposed, together with a quarkless model of particles.  相似文献   

3.
4.
There exist classical systems whose canonical quantization yields relativistic wave equations. As a constructive proof, the classical mechanics of a translating-rotating five-frame is considered. Its quantization yields the Dirac, Weyl, Klein-Gordon, Maxwell-Proca, and higher spin equations, together with a rotational mass spectrum for the states predicted.  相似文献   

5.
6.
Fluidization of Nano-size Particles   总被引:2,自引:0,他引:2  
Fluidization and collapsing bed experiments were performed with 'Tullanox', 10nm diameter fumed silica. The minimum fluidization velocity was determined to be 0.0115m/s at the unusually low volume fraction of solids of 0.0077. The solids volume fraction was measured using a -ray densitometer. Fluidization was without large bubbles, with a high bed expansion ratio. The highest granular temperature was of the order of that of Geldart B particles, as measured by Cody et al. (1996). The sedimentation process was simulated using a two-fluid hydrodynamic model. The input into the model was a measured solids stress modulus and an agglomerate size determined from the settling curves. With these two rheological parameters, there was good agreement between the sedimentation theory and the experiment. This study shows that the standard collapse bed experiment used in industry is a good test of rheological properties of particles.  相似文献   

7.
This paper is a contribution to the problem of particle localization in non-relativistic Quantum Mechanics. Our main results will be (1) to formulate the problem of localization in terms of invariant subspaces of the Hilbert space, and (2) to show that the rigged Hilbert space incorporates particle localization in a natural manner.  相似文献   

8.
In this paper we adopt Peshkin's “maximum complexity method” for reactions 0 + 1/2 → j + s, γ + 0 → j + 0 with polarized initial particles. The produced particles undergo the decays s → 0 + 1/2, and j decays strongly into 0 + 0 + 0. Study of certain correlations in such processes allows to determine the spins of the produced particles. Because the spin of the X° (960) meson is not firmly established we apply the general results obtained to the reactions: K?p → X° Δ, πp → X°N, γHe → X°He.  相似文献   

9.
10.
Modifying a proposal by Harari and Shupe, we associate with each lepton, quark,and gauge boson a fundamental 4-vector with entries ±1 or 0. A Feynman vertexcorresponds to the addition of two fundamental vectors giving rise to a third.  相似文献   

11.
When an optical beam is incident on particles that are randomly distributed, and if the fractional volume is small, single scattering theory is adequate to explain the scattering characteristics of the medium. However, when the fractional volume is increased, multiple scattering effects cannot be ignored. This paper reviews the fundamental theories of multiple scattering including radiative transfer and diffusion theories. Also included are recent studies on polarization effects, localization, enhanced backscattering, resonant localization, pulse scattering and scattering in dense media.  相似文献   

12.
带电粒子与超晶格相互作用及其超高能粒子识别   总被引:2,自引:0,他引:2  
讨论了非沟道粒子与晶体的相互作用及其渡越辐射, 并将渡越辐射同沟道辐射进行了比较, 结果表明, 渡越辐射对沟道辐射的贡献主要是在长波区域使沟道辐射的本底增强; 由于超晶格是由两种不同介电性能的材料交替生长而成的多层薄膜结构, 它的渡越辐射比较强. 正是这个特点, 可望利用超晶格的渡越辐射来识别超高能粒子.  相似文献   

13.
Optics and Spectroscopy - We study the afterglow of a pulsed barrier discharge in helium with a small admixture of neon (10‒2%), which creates a plasma with a low density of metastable...  相似文献   

14.
A synergetic model permitting one to represent modes of motion of a group of living organisms is constructed. It is demonstrated that the translational motion is observed when the internal state parameter exceeds the critical value. The velocity distribution the form of which is determined by the relationship of the intensities of stochastic sources is retrieved.  相似文献   

15.
We briefly discuss the relevant equations for the motion of spinning particles in curved spacetime. We describe the generalized Killing equations for spinning spaces and derive the constants of motion. We apply the formalism to solve for the motion of a pseudoclassical spinning particle in Schwarzschild–de Sitter spacetime.  相似文献   

16.
This paper is about the metaphysical debate whether objects persist over time by the selfsame object existing at different times (nowadays called endurance by metaphysicians), or by different temporal parts, or stages, existing at different times (called perdurance). I aim to illuminate the debate by using some elementary kinematics and real analysis: resources which metaphysicians have, surprisingly, not availed themselves of. There are two main results, which are of interest to both endurantists and perdurantists. (1) I describe a precise formal equivalence between the way that the two metaphysical positions represent the motion of the objects of classical mechanics (both point-particles and continua). (2) I make precise, and prove a result about, the idea that the persistence of objects moving in a void is to be analysed in terms of tracking the continuous curves in spacetime that connect points occupied by matter. The result is entirely elementary: it is a corollary of the Heine–Borel theorem.Dedicated to the memory of Jim Cushing, an amazing mind and a wonderful man.  相似文献   

17.
The finely stratified sphere model was used to calculate electromagnetic fields inside homogeneous and radially inhomogeneous spheres which are illuminated by electromagnetic plane waves. A complete picture of the internal fields is given for spheres whose diameters are comparable to the wavelength (α = 1.5 and 5, where α = 2 πa/γs is the size parameter of the sphere) and spheres whose diameters are much larger than the, wavelength (α as high as 150), for coated spheres (spheres composed of a homogeneous core and a homogeneous shell) and gradient-index spheres (spheres with a continuous of refractive index), for spheres at states of morphology-dependent resonances (MDRs) and those at non-resonant states.  相似文献   

18.
Unstable particles, together with their stable decay products, constitute probability collectives that are defined as Hilbert spaces with dimension higher than one, nondecomposable in a particle basis. Their structure is considered in the framework of Birkhoff-von Neumann's Hilbert subspace lattices. Bases with particle states are related to bases with a diagonal scalar product by a Hilbert-bein involving the characteristic decay parameters (in some analogy to the n-bein structures of metrical manifolds). Probability predictions as expectation values, involving unstable particles, have to take into account all members of the higher dimensional collective. For example, the unitarity structure of the S-matrix for an unstable particle collective can be established by a transformation with its Hilbert-bein.  相似文献   

19.
Diffusion-limited aggregation (DLA) assumes that particles perform pure random walk at a finite temperature and aggregate when they come close enough and stick together. Although it is well known that DLA in two dimensions results in a ramified fractal structure, how the particle shape influences the formed morphology is still unclear. In this work, we perform the off-lattice two-dimensional DLA simulations with different particle shapes of triangle, quadrangle, pentagon, hexagon, and octagon, respectively, and compare with the results for circular particles. Our results indicate that different particle shapes only change the local structure, but have no effects on the global structure of the formed fractal cluster. The local compactness decreases as the number of polygon edges increases.  相似文献   

20.
The efficiency of reactors fed with particulate mixtures is often reduced by segregation of solids. Placing continuous mixers directly ahead of a reactor may be a solution to this problem. The performance of such mixers can be monitored for appropriate binary solids systems with an optical in-line measuring system. The tracer concentration (SiC or Irgalite) in Al(OH)3 was registered with high time resolution, thus making possible an extended statistical analysis of mixing processes using the power density spectrum. Experimental mixers with a maximum -throughput of 300 kg/h were fed with a fluctuating tracer concentration and the variance reduction ratios were determined. A model was developed that takes into account feeding constancy, residence time distribution and the limited homogeneity of particulate mixtures. Diagrams for continuous solids mixing processes are derived therefrom. They demonstrate the importance of high-accuracy feed-rate control.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号