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A Number Theoretic Analysis of the Enthalpy, Enthalpy Energy Density, Thermodynamic Volume, and the Equation of State of a Modified White Hole, and the Implications to the Quantum Vacuum Spacetime, Matter Creation and the Planck Frequency
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作者 Michele Nardelli Amos S. Kubeka Alizera Amani 《Journal of Modern Physics》 2024年第1期1-50,共50页
In this paper, we analyze the enthalpy, enthalpy energy density, thermodynamic volume, and the equation of state of a modified white hole. We obtain new possible mathematical connections with some sectors of Number Th... In this paper, we analyze the enthalpy, enthalpy energy density, thermodynamic volume, and the equation of state of a modified white hole. We obtain new possible mathematical connections with some sectors of Number Theory, Ramanujan Recurring Numbers, DN Constant and String Theory, that enable us to extract the quantum geometrical properties of these thermodynamic equations and the implication to the quantum vacuum spacetime geometry of our early universe as they act as the constraints to the nature of quantum gravity of the universe. 展开更多
关键词 number Theory Ramanujan Recurring numbers DN Constant String Theory Loop Quantum Gravity Matter Creation Enthalpy Energy density Thermodynamic Volume ENTHALPY
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ESTIMATION OF THE NUMBER OF CORRELATED SOURCES WITH COMMON FREQUENCIES BASED ON POWER SPECTRAL DENSITY 被引量:5
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作者 LI Ning SGU Tielin 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2007年第4期88-93,共6页
Blind source separation and estimation of the number of sources usually demand that the number of sensors should be greater than or equal to that of the sources, which, however, is very difficult to satisfy for the co... Blind source separation and estimation of the number of sources usually demand that the number of sensors should be greater than or equal to that of the sources, which, however, is very difficult to satisfy for the complex systems. A new estimating method based on power spectral density (PSD) is presented. When the relation between the number of sensors and that of sources is unknown, the PSD matrix is first obtained by the ratio of PSD of the observation signals, and then the bound of the number of correlated sources with common frequencies can be estimated by comparing every column vector of PSD matrix. The effectiveness of the proposed method is verified by theoretical analysis and experiments, and the influence of noise on the estimation of number of source is simulated. 展开更多
关键词 Blind signal number of sources Power spectral density
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Experimental determination of distributions of soot particle diameter and number density by emission and scattering techniques
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作者 Huawei Liu Shu Zheng 《Chinese Physics B》 SCIE EI CAS CSCD 2019年第1期400-405,共6页
A diagnostics method was presented that uses emission and scattering techniques to simultaneously determine the distributions of soot particle diameter and number density in hydrocarbon flames. Two manta G-504 C camer... A diagnostics method was presented that uses emission and scattering techniques to simultaneously determine the distributions of soot particle diameter and number density in hydrocarbon flames. Two manta G-504 C cameras were utilized for the scattering measurement, with consideration of the attenuation effect in the flames according to corresponding absorption coefficients. Distributions of soot particle diameter and number density were simultaneously determined using the measured scattering coefficients and absorption coefficients under multiple wavelengths already measured with a SOC701 V hyper-spectral imaging device, according to the Mie scattering theory. A flame was produced using an axisymmetric laminar diffusion flame burner with 194 mL/min ethylene and 284 L/min air, and distributions of particle diameter and number density for the flame were presented. Consequently, the distributions of soot volume fraction were calculated using these two parameters as well, which were in good agreement with the results calculated according to the Rayleigh approximation,demonstrating that the proposed diagnostic method is capable of simultaneous determination of the distributions of soot particle diameter and number density. 展开更多
关键词 SOOT PARTICLE DIAMETER SOOT PARTICLE number density SOOT volume FRACTION SCATTERING measurement
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Charged Multiplicity Density and Number of Participant Nucleons in Relativistic Nuclear Collisions
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作者 SABen-Hao CAIXu 《Communications in Theoretical Physics》 SCIE CAS CSCD 2003年第2期212-218,共7页
The energy and centrality dependencies of charged particle pseudorapidity density in relativistic nuclear collisions were studied using a hadron and string cascade model, JPCIAE. Both the relativistic experimental da... The energy and centrality dependencies of charged particle pseudorapidity density in relativistic nuclear collisions were studied using a hadron and string cascade model, JPCIAE. Both the relativistic experimental data and the PHOBOS and PHENIX Au+Au data at RHIC energy could be fairly reproduced within the framework of JPCIAE model and without retuning the model parameters. The predictions for collisions at the LHC energy were also given. We computed the participant nucleon distributions using different methods. It was found that the number of participant nucleons is not a well defined variable both experimentally and theoretically. Thus it may be inappropriate to use the charged particle pseudorapidity density per participant pair as a function of the number of participant nucleons for distinguishing various theoretical models. 展开更多
关键词 charged multiplicity pseudorapidity density number of participant nucleons string fragmentation JPCIAE model
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A Model-Independent Discussion of Quark Number Density and Quark Condensate at Zero Temperature and Finite Quark Chemical Potential
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作者 徐书生 蒋宇 +2 位作者 史潮 崔著钫 宗红石 《Chinese Physics Letters》 SCIE CAS CSCD 2015年第12期14-17,共4页
Generally speaking, the quark propagator is dependent on the quark chemical potential in the dense quantum chromodynamics (QCD). By means of the generating functional method, we prove that the quark propagator actua... Generally speaking, the quark propagator is dependent on the quark chemical potential in the dense quantum chromodynamics (QCD). By means of the generating functional method, we prove that the quark propagator actually depends on p4 + iμ from the first principle of QCD. The relation between quark number density and quark condensate is discussed by analyzing their singularities. It is concluded that the quark number density has some singularities at certain # when T = 0, and the variations of the quark number density as well as the quark condensate are located at the same point. In other words, at a certain # the quark number density turns to nonzero, while the quark condensate begins to decrease from its vacuum value. 展开更多
关键词 QCD A Model-Independent Discussion of Quark number density and Quark Condensate at Zero Temperature and Finite Quark Chemical Potential
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Effect of Particle Number Density on Wave Dispersion in a Two-Dimensional Yukawa System
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作者 张壤月 刘艳红 +2 位作者 黄峰 陈朝阳 李春燕 《Chinese Physics Letters》 SCIE CAS CSCD 2017年第7期155-159,共5页
Effect of the particle number density on the dispersion properties of longitudinal and transverse lattice waves in a two-dimensional Yukawa charged-dust system is investigated using molecular dynamics simulation. The ... Effect of the particle number density on the dispersion properties of longitudinal and transverse lattice waves in a two-dimensional Yukawa charged-dust system is investigated using molecular dynamics simulation. The dispersion relations for the waves are obtained. It is found that the frequencies of both the longitudinal and transverse dust waves increase with the density and when the density is sufficiently high a cutoff region appears at the short wavelength. With the increase of the particle number density, the common frequency tends to increase, and the sound speed of the longitudinal wave also increases, but that of the transverse wave remains low. 展开更多
关键词 Effect of Particle number density on Wave Dispersion in a Two-Dimensional Yukawa System
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Microsegregation and Rayleigh number variation during the solidification of superalloy Inconel 718 被引量:6
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作者 Ling Wang Jianxin Dong +1 位作者 Yuliang Tian Lei Zhang 《Journal of University of Science and Technology Beijing》 CSCD 2008年第5期594-599,共6页
The microstructure and composition of the residual liquid at different temperatures were investigated by scanning electron microscopy (SEM) and energy dispersive X-ray spectrometer (EDX) associated with the Thermo... The microstructure and composition of the residual liquid at different temperatures were investigated by scanning electron microscopy (SEM) and energy dispersive X-ray spectrometer (EDX) associated with the Thermo-calc software calculation of the equilibrium phase diagrams of Inconel 718 and segregated liquid. The liquid density difference and Rayleigh number variation during solidification were estimated as well. It is found that the heavy segregation of Nb in liquid prompts the precipitation of δ and Laves phase directly from liquid and the resultant quenched liquid microstructure consists of pro-eutectic γ+eutectic,or complete eutectic according to the content of Nb from low to high. The liquid density increases with decreasing temperature during the solidification of Inconel 718 and the liquid density difference is positive. The largest relative Rayleigh number occurs at 1320°C when the liquid fraction is about 40vol%. 展开更多
关键词 superalloy Inconel 718 MICROSEGREGATION liquid density difference Rayleigh number
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Modeling Density and Anisotropy of Energetic Electrons Along Magnetic Field Lines 被引量:3
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作者 肖伏良 冯学尚 《Plasma Science and Technology》 SCIE EI CAS CSCD 2006年第3期279-284,共6页
The electromagnetic wave growth or damping depends basically on the number density and anisotropy of energetic particles as the resonant interaction takes place between the particles and waves in the magnetosphere. Th... The electromagnetic wave growth or damping depends basically on the number density and anisotropy of energetic particles as the resonant interaction takes place between the particles and waves in the magnetosphere. The variance of both the number density and anisotropy along the magnetic field line is evaluated systematically by modeling four typically prescribed distribution functions. It is shown that in the case of "the positive anisotropy" (namely, the perpendicular temperature T⊥ exceeds the parallel temperature T||), the number density of energetic electrons always decreases with the magnetic latitude for a regular increasing magnetic field and the maximum wave growth is therefore generally confined to the equator where the resonant energy is minimum, and the number density is the largest. However, the "loss-cone" anisotropy of the electrons with a "pancake" distribution or kappa distribution keeps invariant or nearly invariant, whereas the "temperature" anisotropy with a pure bi-Maxwellian distribution or Ashour-Abdalla and Kennel's distributions decreases with the magnetic latitude. The results may provide a useful approach to evaluating the number density and anisotropy of the energetic electrons at latitudes where the observation information is not available. 展开更多
关键词 number density ANISOTROPY distribution function magnetic field line
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Levy Constrained Search in Fock Space:An Alternative Approach to Noninteger Electron Number 被引量:1
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作者 AYERS Paul W. LEVY Mel 《物理化学学报》 SCIE CAS CSCD 北大核心 2018年第6期625-630,共6页
By extending the Levy wavefunction constrained search to Fock Space,one can define a wavefunction constrained search for electron densities in systems having noninteger number of electrons.For pure-state v-representab... By extending the Levy wavefunction constrained search to Fock Space,one can define a wavefunction constrained search for electron densities in systems having noninteger number of electrons.For pure-state v-representable densities,the results are equivalent to what one would obtain with the zero-temperature grand canonical ensemble.In other cases,the wavefunction constrained search in Fock space presents an upper bound to the grand canonical ensemble functional.One advantage of the Fock-space wavefunction constrained search functional over the zero-temperature grand-canonical ensemble constrained search functional is that certain specific excited states(i.e.,those that are not ground-statev-representable) are the stationary points of the Fock-space functional.However,a potential disadvantage of the Fock-space constrained search functional is that it is not convex. 展开更多
关键词 density FUNCTIONAL theory LEVY CONSTRAINED SEARCH FUNCTIONAL Fock space Fractional electron number Excited-state density FUNCTIONAL theory Universal density FUNCTIONAL Zero temperature grand canonicalensemble Convexity
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Joint probability density function of the stochastic responses of nonlinear structures 被引量:1
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作者 陈建兵 李杰 《Earthquake Engineering and Engineering Vibration》 SCIE EI CSCD 2007年第1期35-47,共13页
The joint probability density fimction (PDF) of different structural responses is a very important topic in the stochastic response analysis of nonlinear structures. In this paper, the probability density evolution ... The joint probability density fimction (PDF) of different structural responses is a very important topic in the stochastic response analysis of nonlinear structures. In this paper, the probability density evolution method, which is successfully developed to capture the instantaneous PDF of an arbitrary single response of interest, is extended to evaluate the joint PDF of any two responses. A two-dimensional partial differential equation in terms of the joint PDF is established. The strategy of selecting representative points via the number theoretical method and sieved by a hyper-ellipsoid is outlined. A two-dimensional difference scheme is developed. The free vibration of an SDOF system is examined to verify the proposed method, and a flame structure exhibiting hysteresis subjected to stochastic ground motion is investigated. It is pointed out that the correlation of different responses results from the fact that randomness of different responses comes from the same set of basic random parameters involved. In other words, the essence of the probabilistic correlation is a physical correlation. 展开更多
关键词 stochastic response NONLINEARITY joint probability density function probability density evolution method number theoretical method finite difference method
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Studies of Structural and Thermodynamic Properties for Polychlorinated Thianthrenes by Density Functional Theory 被引量:1
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作者 刘辉 孙萍 +2 位作者 柳红霞 王遵尧 王连生 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 北大核心 2008年第10期1255-1260,共6页
The structural and thermodynamic (PCTAs) in the ideal gas state at 298.15 K and 1.013 properties of 75 polychlorinated thianthrenes ×10^5 Pa have been calculated at the B3LYP/6- 31G* level using Gaussian 98 pr... The structural and thermodynamic (PCTAs) in the ideal gas state at 298.15 K and 1.013 properties of 75 polychlorinated thianthrenes ×10^5 Pa have been calculated at the B3LYP/6- 31G* level using Gaussian 98 program. Based on the output data of Gaussian, the isodesmic reactions were designed to calculate standard enthalpy of formation (△fH^θ) and standard free energy of formation (△fH^θ) of PCTAs congeners. The relations of these thermodynamic parameters with the number and position of C1 atom substitution (Npcs) were discussed, and it was found that there exists high correlation between thermodynamic parameters (total energy (TE), zero-point vibrational energy (ZPE), thermal correction to energy (Eth), heat capacity at constant volume (Cv^θ), entropy (S^θ), enthalpy (H^θ), free energy (G^θ), standard enthalpies of formation (△fH^θ) and standard Gibbs energies of formation (△fG^θ)) and Npcs. On the basis of the relative magnitude of their △fG^θ, the order of relative stability of PCTA congeners was theoretically proposed. In addition, the correlations between structural parameters and Npcs were also discussed. The good correlations were found between molecular average polarizability (α), energy of the highest occupied molecular orbital (EHOMO), molecular volume (Vm) and Npcs, and all R^2 values are larger than 0.95. Moreover, it was supposed that the isomer groups with higher toxicity should be Tri-CTA and TCTA. 展开更多
关键词 polychlorinated thianthrenes density functional theory (DFT) the number and position of CI atom substitution (Npcs) structural and thermodynamic parameters relative stability
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Effects of Plant Spacing,Row Spacing and Seedling Number Allocation on the Growth Dynamics of Different Populations of Two Types of Rice Varieties 被引量:1
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作者 Jingfang XUE Guangshan ZHAO +7 位作者 Shuqiang CHEN Xiaodong DU Limin YANG Haixin ZHAO Yongsheng CAI Tong ZHOU Linan WANG Mingxu ZHOU 《Agricultural Biotechnology》 CAS 2021年第2期37-44,共8页
[Objectives]This study was conducted to construct high-yielding,high-quality,and high-light-efficiency population structures of different types of rice varieties.[Methods]The effects of plant spacing,row spacing and s... [Objectives]This study was conducted to construct high-yielding,high-quality,and high-light-efficiency population structures of different types of rice varieties.[Methods]The effects of plant spacing,row spacing and seedling number allocation on stems and tillers,leaf area and dynamic traits of high-yielding rice populations(more than 9750 kg/hm^(2))and low-yielding populations(less than 9750 kg/hm^(2))were studied by two kinds of representative rice varieties with different tiller ability and panicle sizes in cold regions.[Results]Decreasing the plant and row spacing and increasing the number of planted seedlings per hole advanced the heading date and made the number of stems and tillers in the population increase.The impact on the super rice variety with fewer tillers and heavier panicles was greater than that of conventional variety with more tillers and lighter panicles.The stems and tillers of the high-yielding high-quality populations grew steadily in the early stage of development,until an appropriate number of panicles was reached at the critical leaf age for productive tillers(June 25),and the peak seedlings should appear in the jointing stage(July 9)with a small number(that value of Longjing 21,the super rice variety with fewer tillers and heavier panicles,was about 1.2 times the expected panicle number,and that of the conventional variety with more tillers and lighter panicles,Kongyu 131,was about 1.1 times the expected panicle number).The populations gradually declined since then,until reaching an appropriate number of panicles at the heading stage.The high-yielding high-quality populations had a higher leaf area index at the heading stage.The value of Longjing 21,the super rice variety with fewer tiller and heavier panicles,reached about 6.0,and that of Kongyu 131,the conventional variety with more tillers and lighter panicles,reached about 4.5.The values decreased thereafter.At the maturation stage,the leaf area index of Longjing 21 remained above 2.5,and that of Kongyu 131 remained above 2.0.[Conclusions]This study has an important guiding role and significance for their high-yielding and high-quality supporting cultivation in cold regions. 展开更多
关键词 Cold region RICE High yield Quality density Seeding number
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Target genes discovery through copy number alteration analysis in human hepatocellular carcinoma 被引量:6
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作者 De-Leung Gu Yen-Hsieh Chen +3 位作者 Jou-Ho Shih Chi-Hung Lin Yuh-Shan Jou Chian-Feng Chen 《World Journal of Gastroenterology》 SCIE CAS 2013年第47期8873-8879,共7页
High-throughput short-read sequencing of exomes and whole cancer genomes in multiple human hepatocellular carcinoma(HCC)cohorts confirmed previously identified frequently mutated somatic genes,such as TP53,CTNNB1 and ... High-throughput short-read sequencing of exomes and whole cancer genomes in multiple human hepatocellular carcinoma(HCC)cohorts confirmed previously identified frequently mutated somatic genes,such as TP53,CTNNB1 and AXIN1,and identified several novel genes with moderate mutation frequencies,including ARID1A,ARID2,MLL,MLL2,MLL3,MLL4,IRF2,ATM,CDKN2A,FGF19,PIK3CA,RPS6KA3,JAK1,KEAP1,NFE2L2,C16orf62,LEPR,RAC2,and IL6ST.Functional classification of these mutated genes suggested that alterations in pathways participating in chromatin remodeling,Wnt/β-catenin signaling,JAK/STAT signaling,and oxidative stress play critical roles in HCC tumorigenesis.Nevertheless,because there are few druggable genes used in HCC therapy,the identification of new therapeutic targets through integrated genomic approaches remains an important task.Because a large amount of HCC genomic data genotyped by high density single nucleotide polymorphism arrays is deposited in the public domain,copy number alteration(CNA)analyses of these arrays is a cost-effective way to reveal target genes through profiling of recurrent and overlapping amplicons,homozygous deletions and potentially unbalanced chromosomal translocations accumulated during HCC progression.Moreover,integration of CNAs with other high-throughput genomic data,such as aberrantly coding transcriptomes and non-coding gene expression in human HCC tissues and rodent HCC models,provides lines of evidence that can be used to facilitate the identification of novel HCC target genes with the potential of improving the survival of HCC patients. 展开更多
关键词 COPY number ALTERATION HIGH-density single NUCLEOTIDE POLYMORPHISM arrays Driver genes HEPATOCELLULAR carcinoma
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Influence of Jet Angle and Ion Density of Cathode Side on Low Current Vacuum Arc Characteristics
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作者 王立军 贾申利 史宗谦 《Plasma Science and Technology》 SCIE EI CAS CSCD 2008年第2期193-197,共5页
In this study, the influence of the initial jet angles (IJAs) and ion number densities (INDs) at the cathode side on the low current vacuum arc (LCVA) characteristics is simulated and analysed. The results show ... In this study, the influence of the initial jet angles (IJAs) and ion number densities (INDs) at the cathode side on the low current vacuum arc (LCVA) characteristics is simulated and analysed. The results show that the ion temperature, electron temperature, ion number density, axial current density and plasma pressure all decrease with the increase of the cathode IJAs. It is also shown that LCVA can cause a current constriction for lower cathode IND, and the anode sheath potential is more nonuniform, which is mainly related to the nonuniform distribution of the axial current density at the anode side. 展开更多
关键词 low current vacuum arc initial jet angles ion number density simulation
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Mathematical modeling of electromagnetic dimensionless number for electromagnetic casting of metals and its application 被引量:1
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作者 王辉 李廷举 金俊泽 《中国有色金属学会会刊:英文版》 CSCD 2005年第3期606-611,共6页
In order to estimate the feasibility of electromagnetic casting (EMC) for different metals, a mathematical model named the electromagnetic dimensionless number (EMDN) was presented, and its validity was proved by the ... In order to estimate the feasibility of electromagnetic casting (EMC) for different metals, a mathematical model named the electromagnetic dimensionless number (EMDN) was presented, and its validity was proved by the experiments of aluminum and Sn-3%Pb alloy. From the experiment and the analysis of EMDN it can be concluded that the EMC of steel can be attained only when the magnetic flux density is larger than 0.09T, while that required for aluminum is only 0.04T. The mathematical expression of the electromagnetic dimensionless number was given out. 展开更多
关键词 电磁维度 电磁铸造 磁流体密度 数学模型 EMDN
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Particle Density in Zero Temperature Symmetry Restoring Phase Transitions in Four-Fermion Interaction Models
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作者 ZHOUBang-Rong 《Communications in Theoretical Physics》 SCIE CAS CSCD 2004年第2期247-251,共5页
By means of critical behaviors of the dynamical fermion mass in four-fermion interaction models, we show by explicit calculations that when T = 0 the particle density will have a discontinuous jumping across the criti... By means of critical behaviors of the dynamical fermion mass in four-fermion interaction models, we show by explicit calculations that when T = 0 the particle density will have a discontinuous jumping across the critical chemical potential μ<SUB>c</SUB> in 2D and 3D Gross-Neveu (GN) model and these physically explain the first-order feature of the corresponding symmetry restoring phase transitions. For the second-order phase transitions in the 3D GN model when T → 0 and in 4D Nambu–Jona–Lasinio (NJL) model when T = 0, it is proven that the particle density itself will be continuous across μ<SUB>c</SUB> but its derivative over the chemical potential μ will have a discontinuous jumping. The results give a physical explanation of implications of the tricritical point in the 3D GN model. The discussions also show effectiveness of the critical analysis approach of phase transitions. 展开更多
关键词 Gross-Neveu and Nambu-Jona-Lasinio models symmetry restoration at zero temperature and high density particle number density first- and second-order phase transitions
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Ensuring Quality of Random Numbers from TRNG: Design and Evaluation of Post-Processing Using Genetic Algorithm
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作者 Jose J. Mijares Chan Parimala Thulasiraman +1 位作者 Gabriel Thomas Ruppa Thulasiram 《Journal of Computer and Communications》 2016年第4期73-92,共20页
Random numbers generated by pseudo-random and true random number generators (TRNG) are used in a wide variety of important applications. A TRNG relies on a non-deterministic source to sample random numbers. In this pa... Random numbers generated by pseudo-random and true random number generators (TRNG) are used in a wide variety of important applications. A TRNG relies on a non-deterministic source to sample random numbers. In this paper, we improve the post-processing stage of TRNGs using a heuristic evolutionary algorithm. Our post-processing algorithm decomposes the problem of improving the quality of random numbers into two phases: (i) Exact Histogram Equalization: it modifies the random numbers distribution with a specified output distribution;(ii) Stationarity Enforcement: using genetic algorithms, the output of (ii) is permuted until the random numbers meet wide-sense stationarity. We ensure that the quality of the numbers generated from the genetic algorithm is within a specified level of error defined by the user. We parallelize the genetic algorithm for improved performance. The post-processing is based on the power spectral density of the generated numbers used as a metric. We propose guideline parameters for the evolutionary algorithm to ensure fast convergence, within the first 100 generations, with a standard deviation over the specified quality level of less than 0.45. We also include a TestU01 evaluation over the random numbers generated. 展开更多
关键词 True Random number Generators Genetic Algorithms Auto-Correlation ENTROPY Power Spectral density
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A Study on Numerical Calculation Method of Small Cluster Density in Percolation Model
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作者 Xucheng Wang Junhui Gao 《Journal of Applied Mathematics and Physics》 2016年第8期1507-1512,共6页
Percolation theory deals with the numbers and properties of the clusters formed in the different occupation probability. In this Paper, we study the calculation method of small clusters. We calcu-lated the small clust... Percolation theory deals with the numbers and properties of the clusters formed in the different occupation probability. In this Paper, we study the calculation method of small clusters. We calcu-lated the small cluster density of 1, 2 and 3 in the percolation model with the exact method and the numerical method. The results of the two methods are very close, which can be verified by each other. We find that the cluster density of all three kinds of small clusters reaches the highest value when the occupation probability is between 0.1 and 0.2. It is very difficult to get the analytical formula for the exact method when the cluster area is relatively large (such as the area is more than 50), so we can get the density value of the cluster by numerical method. We find that the time required calculating the cluster density is proportional to the percolation area, which is indepen-dent of the cluster size and the occupation probability. 展开更多
关键词 Percolation Model Cluster number density Numerical Method
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An Inquiry into Two Intriguing Values of the Critical Current Density of Bi-2212
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作者 Gulshan Prakash Malik Vijaya Shankar Varma 《World Journal of Condensed Matter Physics》 CAS 2021年第3期53-64,共12页
The empirically reported values of the critical current density (<i>j<sub>c</sub></i>) of Bi-2212 as 2.4 × 10<sup>5</sup> (<i>j<sub>c</sub></i><sub&g... The empirically reported values of the critical current density (<i>j<sub>c</sub></i>) of Bi-2212 as 2.4 × 10<sup>5</sup> (<i>j<sub>c</sub></i><sub>1</sub>;Sample 1) and 1.0 × 10<sup>6</sup> A/cm<sup>2</sup> (<i>j<sub>c</sub></i><sub>2</sub>;Sample 2) are intriguing because both of them correspond to the <i>same</i> values of the temperature <i>T</i> = 4.2 K and the applied magnetic field <i>H</i> = 12 × 10<sup>4</sup> G. This difference is conventionally attributed to such factors—not all of which are quantifiable—as the geometry, dimensions and the nature of dopants and the manners of preparation of the samples which cause their granular structures, grain boundaries, alignment of the grains and so on to differ. Based on the premise that the chemical potential <i>μ</i> subsumes most of these features, given herein is a novel explanation of the said results in terms of the values of <i>μ</i> of the two samples. This paper revisits the problem that was originally addressed in [Malik G.P., Varma V.S. (2020) WJCMP, 10, 53-70] in the more accurate framework of a subsequent paper [Malik G.P., Varma V.S. (2021) JSNM, 34, 1551-1561]. Besides, it distinguishes between the contributions of the electro-electron (<i>e-e</i>) and the hole-hole (<i>h-h</i>) pairs to <i>j<sub>c</sub></i>—a feature to which no heed was paid earlier. The essence of our findings is that the <i>j<sub>c</sub></i>s of the two samples differ because they are characterized by different values of the <i>primary</i> variables <i>μ<sub>i</sub></i><sub> </sub>and <img src="Edit_e1b831e9-dc51-4c3b-bd84-fa905e3e62b5.png" alt="" />, where <img src="Edit_1f775a80-30ab-447d-861f-afb4ba8fba6a.png" alt="" /> is the effective mass of a charge-carrier and <i>m<sub>e</sub></i><sub> </sub>is the free-electron mass and <i>i</i> = 1 and 2 denote Sample 1 and Sample 2, respectively. In the scenario of the charge-carriers being <i>predominantly h-h</i> pairs, the values of these parameters are estimated to be: <i>μ</i><sub>1</sub> ≈ 12.3 meV, <i>η</i><sub>1</sub> ≈ 0.58;<i>μ</i><sub>2</sub> ≈ 22.7 meV, <i>η</i><sub>2</sub> ≈ 0.94. Following from these and similar estimates when the charge-carriers are <i>e-e</i> pairs, given below for each sample are the detailed results for the values of the <i>secondary</i> variables viz. the number density of the charge-carriers and their critical velocity, the number of occupied Landau levels and the magnetic interaction parameter. 展开更多
关键词 Chemical Potential- Temperature- and Applied Magnetic Field-Dependent Critical Current density of Superconductors number density Landau Quantization Law of Equipartition of Energy BI-2212
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Ultrafast Laser Energy Density and Retinal Absorption Cross-Section Determination by Saturable Absorption Measurements
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作者 Alfons Penzkofer Meike Luck +1 位作者 Tilo Mathes Peter Hegemann 《Journal of Analytical Sciences, Methods and Instrumentation》 2014年第1期19-26,共8页
Laser pulse nonlinear transmission measurements through saturable absorbers of known absorption parameters allow the measurement of their energy density. On the other hand, nonlinear transmission measurements of laser... Laser pulse nonlinear transmission measurements through saturable absorbers of known absorption parameters allow the measurement of their energy density. On the other hand, nonlinear transmission measurements of laser pulses of known energy density through absorbing media allow their absorption parameter determination. The peak energy density w0P of second harmonic pulses of a mode-locked titanium sapphire laser at wavelength λP = 400 nm is determined by nonlinear energy transmission measurement TE through the dye ADS084BE (1,4-bis(9-ethyl-3-car-bazovinylene)-2-methoxy-5-(2’-ethyl-hexyloxy)-benzene) in tetrahydrofuran. TE(w0P) calibration curves are calculated for laser pulse peak energy density reading w0P from measured pulse energy transmissions TE. The ground-state absorption cross-section σP and the excited-state absorption cross-section σex at λP, and the number density N0 of the retinal Schiff base isoform RetA in pH 7.4 buffer of the blue-light adapted recombinant rhodopsin fragment of the histidine kinase rhodopsin HKR1 from Chlamydomonas reinhardtii were determined by picosecond titanium sapphire second harmonic laser pulse energy transmission measurement TE through RetA as a function of laser input peak energy density w0P. The complete absorption cross-section spectrum 展开更多
关键词 Laser Pulse Peak Energy density DETERMINATION Ground-State ABSORPTION CROSS-SECTION DETERMINATION Excited-State ABSORPTION CROSS-SECTION DETERMINATION Saturable ABSORPTION ADS084BE Dye Histidine Kinase RHODOPSIN HKR1 RETINAL Schiff Base RetA Cofactor number density DETERMINATION
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