American Journal of Modern Physics最新文献_第4页

Dynamics of Dusty Pair-Ion-Electron Plasma Modeled by the Cylindrical Kadomtsev-Petviashvili Equations 用圆柱Kadomtsev-Petviashvili方程模拟的尘埃对离子-电子等离子体动力学

American Journal of Modern Physics Pub Date : 2021-03-17 DOI: 10.11648/J.AJMP.20211001.13

Bertrand Noel Tagne Wafo, F. M. Kakmeni

引用次数: 1

The Evolution of Star Formation Rate Density of Galaxies 星系中恒星形成速率密度的演化

American Journal of Modern Physics Pub Date : 2021-02-20 DOI: 10.11648/J.AJMP.20211001.11

J. Wirsich

{"title":"The Evolution of Star Formation Rate Density of Galaxies","authors":"J. Wirsich","doi":"10.11648/J.AJMP.20211001.11","DOIUrl":"https://doi.org/10.11648/J.AJMP.20211001.11","url":null,"abstract":"We present a semi-analytical calculation of the global star formation density (SFD) by using the well constrained cold dark matter (CDM) halo mass function. Both, halo masses MH(z) and stellar masses M*(z) are taken from observations of Lyα emitter (LAEs) and/or Lyman break galaxies (LBGs). Most of them, spectroscopically selected, are characterized by high star formation rates. The view of galaxy formation is mainly based on the hierarchical (“botton-up”) cold dark matter model for structure formation. We have used the connection between the halo mass and the star formation rate in galaxies of the halo mass MH at redshift z. Our model has the advantage that we are able to calculate the global star formation rate ρ*(z) (in Mʘy-1Mpc-3) by a closed equation. All parameters (MH; M* and n) have a well-defined physical meaning. From the CDM spectrum, the power law index of the halo mass function is well constrained. Our results are compiled in Table 1 and Figure 1. Here our results are compared with observations and hydrodynamical simulations. The physical meaning of the evolution of comoving cosmic star density as a function of redshift with three epochs is discussed. We find a good agreement between the SFD inferred from observations and our model in the range of redshifts z = 0 - 7.","PeriodicalId":7717,"journal":{"name":"American Journal of Modern Physics","volume":"20 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-02-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89431150","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Thermoelectric and Galvanomagnetic Properties of the Alloy Bi₂Te₃ + 0.04 Weight% Ni in the Temperature Range 77 ÷ 300 K Bi2Te3 + 0.04重量% Ni合金在77 ~ 300 K温度范围内的热电和电磁性能

American Journal of Modern Physics Pub Date : 2021-01-01 DOI: 10.11648/j.ajmp.20211006.12

Toolanboy Marifjonovich Azimov, Kizlarhon Isroilovna Gaynazarova, Maksadjon Karimberdiyvich Onarkulov, Abror Abduvosidovich Yuldashev

引用次数: 1

Determining the Dirac CP Violation Phase and Neutrino Mass Hierarchy 确定狄拉克CP破坏相和中微子质量层次

American Journal of Modern Physics Pub Date : 2021-01-01 DOI: 10.11648/j.ajmp.20211004.11

Zoran Bozidar Todorovic

引用次数: 0

Nucleation Phenomena Interpreted by Fluctuation/Dissipation Theory 波动/耗散理论解释的成核现象

American Journal of Modern Physics Pub Date : 2021-01-01 DOI: 10.11648/j.ajmp.20211003.12

Nicholas F. Borrelli, Joseph F. Schroeder

引用次数: 0

Elastic Scattering of Electrons by Helium Atoms in Born Approximation 玻恩近似下氦原子对电子的弹性散射

American Journal of Modern Physics Pub Date : 2020-12-08 DOI: 10.11648/J.AJMP.20200906.11

S. Diallo, L. Gomis, I. Faye, M. Tall, I. Diédhiou

{"title":"Elastic Scattering of Electrons by Helium Atoms in Born Approximation","authors":"S. Diallo, L. Gomis, I. Faye, M. Tall, I. Diédhiou","doi":"10.11648/J.AJMP.20200906.11","DOIUrl":"https://doi.org/10.11648/J.AJMP.20200906.11","url":null,"abstract":"Elastic scattering phenomena arising in electron-helium scattering are dominant processes. The determination of accurate elastic differential cross sections for electron-helium scattering has a considerable importance. An accurate calculation of the plane-wave first Born exchange amplitude of electrons elastic scattering by helium atoms is reported. The direct and exchange amplitudes are calculated analytically from the Hartree-Fock orbital wave functions by using a variational method. The forms of these wave functions are very suitable for analytical calculations and powerful to generalize to more complex atomic systems. The interaction potential is modelled by the static Coulomb interaction between the incident electron and the atomic system. The differential cross sections are calculated at intermediate energies taking into account the exchange effects. We have established in the high energies region, by neglecting the exchange effects, the analytical expressions of the total and momentum transport cross sections suitable for the calculation of the plasma transport properties. A very compact form of the Born amplitude has been proposed as a finite series of Gaussian functions, which represents a major tool in the calculations of differential cross sections of two-electron atomic systems. Numerical results are used to analyze the contribution of the exchange amplitude to the differential cross sections at intermediate and high energies. The differential cross sections are calculated for the energy range 30-400 eV. We find good agreement in high energy domain scattering with experimental results and other sophisticated calculations without using any adjustable parameter.","PeriodicalId":7717,"journal":{"name":"American Journal of Modern Physics","volume":"72 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-12-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86140026","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

A Theoretical Explanation on Gell-Mann-Nishijima Formula with Singular Number and the Establishment of Lepton Quantum Number Constrained Equation 奇异数Gell-Mann-Nishijima公式的理论解释及轻子量子数约束方程的建立

American Journal of Modern Physics Pub Date : 2020-12-08 DOI: 10.11648/J.AJMP.20200906.12

Hua Ma

{"title":"A Theoretical Explanation on Gell-Mann-Nishijima Formula with Singular Number and the Establishment of Lepton Quantum Number Constrained Equation","authors":"Hua Ma","doi":"10.11648/J.AJMP.20200906.12","DOIUrl":"https://doi.org/10.11648/J.AJMP.20200906.12","url":null,"abstract":"In this paper, two fundamental problems of particle physics are studied theoretically. The first one is: to solve the problem of establishing general quantum number constrained equation, the symmetry transformation mechanism of charge eigenstates for elementary particles is adopted, and the general quantum number constrained equations are established, which are applicable to physical particles. For hadrons, an equation is completely consistent with Gell-Mann-Nishijima formula. For leptons, the lepton quantum numbers are exactly the solutions of an equation, which is just the lepton quantum number constrained equation. The second problem is: to solve the problem of understanding singularity and calculating singular numbers, a hypothesis that a composite particle may has virtual structure is proposed. According to this hypothesis, the singular particles must be composite particles, and have virtual structures. In a virtual structure, the particles and antiparticles of component particles can form particle-antiparticle pairs, which have great influence such as improving mass and changing life of composite particles. Therefore, the composite particle with particle-antiparticle pairs in its virtual structure is singular particle, and the singular number is the number of particle-antiparticle pairs. These two theoretical results are in good agreement with the already achieved experimental results of particle physics, can explain the related phenomena of physical particles from a deeper physical mechanism, and theoretically predict the existence of singular leptons and several new singular hadrons.","PeriodicalId":7717,"journal":{"name":"American Journal of Modern Physics","volume":"33 1","pages":"84"},"PeriodicalIF":0.0,"publicationDate":"2020-12-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81057457","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 2

On the Justification and Validity of the Kennard Inequality 论肯纳德不等式的正当性和有效性

American Journal of Modern Physics Pub Date : 2020-12-04 DOI: 10.11648/j.ajmp.20200905.12

Haengjin Choe

{"title":"On the Justification and Validity of the Kennard Inequality","authors":"Haengjin Choe","doi":"10.11648/j.ajmp.20200905.12","DOIUrl":"https://doi.org/10.11648/j.ajmp.20200905.12","url":null,"abstract":"In 1927, Earle Hesse Kennard derived an inequality describing Heisenberg’s uncertainty principle. Since then, we have traditionally been using the standard deviation as the measure of uncertainty in quantum mechanics. But Jan Hilgevoord asserts that the standard deviation is neither a natural nor a generally adequate measure of quantum uncertainty. Specifically, he asserts that the standard deviations are inadequate to use as the quantum uncertainties in the single- and double-slit diffraction experiments. He even tells that from these examples it will become clear that the standard deviation is the wrong concept to express the uncertainty principle generally and that the Kennard relation has little to do with the uncertainty principle. We will investigate what are adequate as the measures of quantum uncertainty. And, beyond that, we will investigate the effects of multiplying the two uncertainties; namely, characteristics which is hiding in deep interior of the Kennard inequality. Through investigations we’ll come to naturally realize that his assertions were wrong. All of our discussions will help raise understanding of the Heisenberg uncertainty principle. Our discussions will afford us an opportunity to think about the essence of the Fourier transform. The aim of this paper is to draw conclusions about whether the Kennard inequality is justified or not.","PeriodicalId":7717,"journal":{"name":"American Journal of Modern Physics","volume":"70 1","pages":"73"},"PeriodicalIF":0.0,"publicationDate":"2020-12-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78855580","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Dynamics of the Quantum Discord with Weak Measurement for a Two-atom System in Thermal Reservoirs 热储中双原子系统量子不和谐的弱测量动力学

American Journal of Modern Physics Pub Date : 2020-11-11 DOI: 10.11648/j.ajmp.20200905.11

M. Bai, H. Xu, Xue-qun Yan

{"title":"Dynamics of the Quantum Discord with Weak Measurement for a Two-atom System in Thermal Reservoirs","authors":"M. Bai, H. Xu, Xue-qun Yan","doi":"10.11648/j.ajmp.20200905.11","DOIUrl":"https://doi.org/10.11648/j.ajmp.20200905.11","url":null,"abstract":"Weak measurement is a kind of state partial collapse measurement developed on the basis of von Neumann measurement and positive operator value measurement, which allows us to explore the quantum world which has the least influence on the research system. Based on the weak measurement theory, the dynamics of quantum discord for two isolated atoms in their own thermal reservoirs is presented. We examine the time evolution of both standard quantum discord and quantum discord with weak measurement for the two-atom system, and analyzes the differences between the standard quantum discord and quantum discord with weak measurement in the evolution process with time, as well as the general role of the strength parameter in determing the discord and affecting its dynamic evolution. We show that quantum discords depend on how weak or strong one perturbs the quantum system. We also show that the difference of the standard quantum discord and the quantum discord with weak measurements increases as the strength parameter decreases. This means that the weak measurements can capture more quantum discord of a bipartite system. Our results show that the weak measurement performed on one of the subsystems can lead to the quantum discord that is a more natural measure of quantum correlations than the standard quantum discord captured by the projective measurements.","PeriodicalId":7717,"journal":{"name":"American Journal of Modern Physics","volume":"4 1","pages":"68"},"PeriodicalIF":0.0,"publicationDate":"2020-11-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81974443","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Charge-Mass Equivalence leading to Ilectron from the Electron 从电子产生电子的电荷-质量等价

American Journal of Modern Physics Pub Date : 2020-09-15 DOI: 10.11648/J.AJMP.20200904.12

D. Giri, Ian Leonard Gallon, C. Baum

{"title":"Charge-Mass Equivalence leading to Ilectron from the Electron","authors":"D. Giri, Ian Leonard Gallon, C. Baum","doi":"10.11648/J.AJMP.20200904.12","DOIUrl":"https://doi.org/10.11648/J.AJMP.20200904.12","url":null,"abstract":"Hydrogen atom was considered as the smallest “bit of matter” until the electron was discovered. Nearly all attributes of the electron have been experimentally measured except for its radius. Electron’s radius has been derived in classical mechanics. The angular momentum of the electron has been understood as a purely quantum mechanical effect. In this paper, we have established an equivalence between the charge and mass of a fundamental particle. This leads to a definition of a complex charge or a complex mass, which combine both charge and mass. Every fundamental particle with charge and mass can be defined by a single complex charge. Interaction of two complex charges leads to the familiar Coulomb and Gravitational forces. It also points out the possibility of a 5th force of nature. By writing the charge and mass of the electron as mass and charge, we come up with a new particle which we have called the ilectron. Some attributes of the ilectron have been derived in this paper and its relation to Planck’s mass and charge are explored. This is a comprehensive paper that has been adapted from material we published in [1-3] for disseminating this information in the Physics community.","PeriodicalId":7717,"journal":{"name":"American Journal of Modern Physics","volume":"80 1","pages":"60"},"PeriodicalIF":0.0,"publicationDate":"2020-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88531457","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1