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First Digit Distributions of Gamma-Ray Bursts

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Research in Astronomy and Astrophysics 2024年第5期24卷 70-75页

作者： Hou-Yu Lai jun-jie wei Purple Mountain Observatory Chinese Academy of SciencesNanjing 210023China School of Astronomy and Space Sciences University of Science and Technology of ChinaHefei 230026China

The occurrence of the first significant digits from real world sources is usually not equally distributed,but is consistent with a logarithmic distribution instead,known as Benford’s *** this work,we perform a comprehensive investigation on the first digit distributions of the duration,fluence,and energy flux of gamma-ray bursts (GRBs) for the first *** a complete GRB sample detected by the Fermi satellite,we find that the first digits of the duration and fluence adhere to Benford’s ***,the energy flux shows a significant departure from this law,which may be due to the fact that a considerable part of the energy flux measurements is restricted by lack of spectral *** on the conventional duration classification scheme,we also check if the durations and fluences of long and short GRBs (with duration T_(90)>2 s and T_(90)≤2 s,respectively) obey Benford’s *** find that the fluences of both long and short GRBs still agree with the Benford distribution,but their durations do not follow Benford’s *** results hint that the long–short GRB classification scheme does not directly represent the intrinsic physical classification scheme.

关键词： (stars:)gamma-ray burst general-methods statistical-astronomical databases miscellaneous

Stability and Bifurcation Analysis in a System of Four Coupled Neurons with Multiple Delays

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Acta Mathematicae Applicatae Sinica 2013年第2期29卷 425-448页

作者： Xiu-ling LI jun-jie wei College of Applied Mathematics Jilin University of Finance and Economics Department of Mathematics Harbin Institute of Technology

A system of delay differential equations is studied which represent a model for four neurons with time delayed connections between the neurons and time delayed feedback from each neuron to itself. The linear stability and bifurcation of the system are studied in a parameter space consisting of the sum of the time delays between the elements and the product of the strengths of the connections between the elements. Meanwhile, the bifurcation set are drawn in the parameter space.

关键词： stability bifurcation multiple delays

Diffusion-induced Spatio-temporal Oscillations in an Epidemic Model with Two Delays

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Acta Mathematicae Applicatae Sinica 2022年第1期38卷 128-153页

作者： Yan-fei DU Ben NIU jun-jie wei School of Mathematics Harbin Institute of TechnologyHarbin 150001China School of Mathematics&Data Science Shaanxi University of Science and TechnologyXi'an 710021China Department of Mathematics Harbin Institute of TechnologyWeihai 264209China School of Science Jimei UniversityXiamen 361021China

We investigate a diffusive,stage-structured epidemic model with the maturation delay and freelymoving *** delays and diffusive rates as bifurcation parameters,the only possible way to destabilize the endemic equilibrium is through Hopf *** normal forms of Hopf bifurcations on the center manifold are calculated,and explicit formulae determining the criticality of bifurcations are *** are two different kinds of stable oscillations near the first bifurcation:on one hand,we theoretically prove that when the diffusion rate of infected immature individuals is sufficiently small or sufficiently large,the first branch of Hopf bifurcating solutions is always spatially homogeneous;on the other,fixing this diffusion rate at an appropriate size,stable oscillations with different spatial profiles are observed,and the conditions to guarantee the existence of such solutions are given by calculating the corresponding eigenfunction of the Laplacian at the first Hopf bifurcation *** bifurcation behaviors indicate that spatial diffusion in the epidemic model may lead to spatially inhomogeneous distribution of individuals.

关键词： epidemic model stage structure delay diffusion Hopf bifurcation spatio-temporal oscillation

Combined limit on the photon mass with nine localized fast radio bursts

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Research in Astronomy and Astrophysics 2020年第12期20卷 330-336页

A nonzero-mass hypothesis for the photon can produce a frequency-dependent dispersion of light, which results in arrival-time differences of photons with different frequencies originating from a given transient source. Extragalactic fast radio bursts(FRBs), with their low frequency emissions, short time durations, and long propagation distances, are excellent astrophysical probes to constrain the rest mass of the photon mγ. However, the derivation of a limit on mγis complicated by the similar frequency dependences of dispersion expected from the plasma and nonzero photon mass effects. If a handful measurements of redshift for FRBs are available, then the different redshift dependences of the plasma and photon mass contributions to the dispersion measure(DM) might be able to break dispersion degeneracy in testing the photon mass. For now, nine FRBs with redshift measurements have been reported, which can turn this idea into reality. Taking into account the DM contributions from both the plasma and a possible photon mass,we use the data on the nine FRBs to derive a combined limit of mγ≤ 7.1 × 10^-51 kg, or equivalently mγ≤ 4.0 × 10^-15 e V/c2 at 68% confidence level, which is essentially as good as or represents a factor of 7 improvement over previous limits obtained by the single FRBs. Additionally, a reasonable estimation for the DM contribution from the host galaxy, DMhost, can be simultaneously achieved in our analysis. The rapid progress in localizing FRBs will further tighten the constraints on both mγ and DMhost.

关键词： radio continuum:general intergalactic medium astroparticle physics

Self-organized criticality in multi-pulse gamma-ray bursts

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Frontiers of physics 2021年第1期16卷 91-98页

作者： Fen Lyu Ya-Ping Li Shu-Jin Hou jun-jie wei Jin-jun Geng Xue-Feng Wu Purple Mountain Observatory Chinese Academy of SciencesNanjing 210023China University of Chinese Academy of Sciences Beijing 100049China Theoretical Division Los Alamos National LaboratoryLos AlamosNM 87545USA College of Physics and Electronic Engineering Nanyang Normal UniversityNanyang 473061China School of Astronomy and Space Science University of Science and Technology of ChinaHefei 230026China School of Astronomy and Space Science Nanjing UniversityNanjing 210023China Institute of Astronomy and Astrophysics University of TubingenAuf der Morgenstelle 10D-72076TubingenGermany

The variability in multi-pulse gamma-ray bursts(GRBs)may help to reveal the mechanism of underlying processes from the central *** investigate whether the self-organized criticality(SOC)phenomena exist in the prompt phase of GRBs,we statistically study the proper ties of GRBs with more than 3 pulses in each burst by fitting the distributions of several observed physical variables with a Markov Chain Monte Carlo approach,including the isotropic energy E_(iso),the duration time T,and the peak count rate P of each *** sample consists of 454 pulses in 93 GRBs observed by the CGRO/BATSE *** best-fitting values and uncertainties for these power-law indices of the differential frequency distributions are:α_(E)^(d)=1.54±0.09,α_(T)^(d)=1.82_(-0.15)^(+0.14)andα_(P)^(d)=2.09_(-0.19)^(0.18),while the power-law indices in the cumulative frequency distributions are:α_(E)^(c)=1.44_(-0.10)^(+0.08),α_(T)^(c)=1.75_(-0.13)^(0.11)andα_(P)^(c)=1.99_(-0.19)^(+0.16).We find that these distributions are roughly consistent with the physical framework of a Fractal-Diffusive,Self^Organized Criticality(FD-SOC)system with the spatial dimension S=3 and the classical diffusionβ=*** results support that the jet responsible for the GRBs should be magnetically dominated and magnetic instabilities(e.g.,kink model,or tearing-model instability)lead the GRB emission region into the SOC state.

关键词： gamma-ray burst general methods statistical

A Mechanically Strong Conductive Hydrogel Reinforced by Diaminotriazine Hydrogen Bonding

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Chinese Journal of Polymer Science 2017年第10期35卷 1222-1230页

作者： Qian Wu Bing Xu jun-jie wei Qing Wang Qi-gang Wang 刘文广 School of Materials Science and Engineering Tianjin Key Laboratory of Composite and Functional Materials Tianjin University Tianjin 300350 China School of Chemical Science and Engineering Tongji University Shanghai 200092 China

Over the past decades, the urgent need for high strength conductive hydrogels in diverse applications has motivated an unremitting effort to combine the improved mechanical properties of hydrogels with conductive performances. In this work, high strength conductive hydrogels intensified with intermolecular hydrogen bonding are fabricated by in situ mixing poly（2-vinyl-4,6-diamino-1,3,5-triazine-co-polyethylene glycol diacrylates）（PVDT-PEGDA） hydrogels with poly（3,4-ethylenedioxythiophene）-poly（styrenesulfonate）（PEDOT/PSS）. The conductive hydrogels in deionized water exhibit high mechanical performances with compressive strength and tensile strength in the range of 7.58-9.52 MPa and 0.48-1.20 MPa respectively, which are ascribed to the intermolecular hydrogen bonding interactions of diaminotriazinediaminotriazine（DAT-DAT） in the network. Meanwhile, adding PEDOT/PSS can significantly increase both the specific conductivities and equilibrium water contents of the hydrogels. These cytocompatible conductive hydrogels may have a great potential to be used as electrical stimuli responsive soft biomaterials.

关键词： adhesive swell closure inorganic colorful hydrophobic clearly candidate healing equiv

New limits on the photon mass with radio pulsars in the Magellanic clouds

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Research in Astronomy and Astrophysics 2017年第2期17卷 17-21页

作者： jun-jie wei Er-Kang Zhang Song-Bo Zhang Xue-Feng Wu Purple Mountain Observatory Chinese Academy of SciencesNanjing 210008China Guangxi Key Laboratory for Relativistic Astrophysics Nanning 530004China Department of Physics University of California San Diego9500 Gilman Dr.La JollaCalifornia 92093USA University of Chinese Academy of Sciences Beijing 100049China Joint Center for Particle Nuclear Physics and CosmologyNanjing University-Purple Mountain ObservatoryNanjing 210008China School of Astronomy and Space Science University of Science and Technology of ChinaHefei 230026China

A conservative constraint on the rest mass of the photon can be estimated under the assump- tion that the frequency dependence of dispersion from astronomical sources is mainly contributed by the nonzero photon mass effect. Photon mass limits have been set earlier through the optical emissions of the Crab Nebula pulsar, but we demonstrate that these limits can be significantly improved with the dispersion measure （DM） measurements of radio pulsars in the Large and Small Magellanic Clouds. The combination of DM measurements of pulsars and distances of the Magellanic Clouds provides a strict upper limit on the photon mass as low as mγ≤2.0 ～ 10-45 g, which is at least four orders of magnitude smaller than the constraint from the Crab Nebula pulsar. Although our limit is not as tight as the current best result （～ 10-47 g） from a fast radio burst （FRB 150418） at a cosmological distance, the cosmological origin of FRB 150418 remains under debate; and our limit can reach the same high precision of FRB 150418 when it has an extragalactic origin （～10-45 g）.

关键词： pulsars: general -- Magellanic Clouds -- astroparticle physics

Regulation of seed traits in soybean

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aBIOTECH 2023年第4期4卷 372-385页

作者： Yang Hu Yue Liu jun-jie wei Wan-Ke Zhang Shou-Yi Chen Jin-Song Zhang State Key Lab of Plant Genomics Institute of Genetics and Developmental BiologyInnovative Academy of Seed DesignChinese Academy of SciencesBeijing 100101China College of Advanced Agricultural Sciences University of Chinese Academy of SciencesBeijing 100049China

Soybean (Glycine max) is an essential economic crop that provides vegetative oil and protein forhumans, worldwide. Increasing soybean yield as well as improving seed quality is of great *** weight/size, oil and protein content are the three major traits determining seed quality, and seedweight also influences soybean yield. In recent years, the availability of soybean omics data and thedevelopment of related techniques have paved the way for better research on soybean functionalgenomics, providing a comprehensive understanding of gene functions. This review summarizes theregulatory genes that influence seed size/weight, oil content and protein content in soybean. We alsoprovided a general overview of the pleiotropic effect for the genes in controlling seed traits andenvironmental stresses. Ultimately, it is expected that this review will be beneficial in breedingimproved traits in soybean.

关键词： Soybean Seed weight and size Oil Protein

A comparison between repeating bursts of FRB 121102 an giant pulses from Crab pulsar and its applications

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Frontiers of physics 2021年第2期16卷 201-207页

作者： Fen Lyu Yan-Zhi Meng Zhen-Fan Tang Ye Li jun-jie wei Jin-jun Geng Lin Lin Can-Min Deng Xue-Feng Wu Purple Mountain Observatory Chinese Academy of SciencesNanjing 210023China University of Chinese Academy of Sciences Beijing 100049China School of Astronomy and Space Science Nanjing UniversityNanjing 210023China Kavli Institute for Astronomy and Astrophysics Peking UniversityBeijing 100871China Institute of Astronomy and Astrophysics University of TubingenAuf der Morgenstelle 10D-72076TubingenGermany Department of Astronomy Beijing Normal UniversityBeijing 100875China Department of Astronomy University of Science and Technology of ChinaHefei 230026China School of Astronomy and Space Sciences University of Science and Technology of ChinaHefei 230026China

There are some similarities between bursts of repeating fast radio bursts(FRBs)and giant pulses(GPs)of *** explore possible relations between them,we study the cumulative energy distributions of these two phenomena using the observations of repeating FRB 121102 and the GPs of Crab *** find that the power-law slope of GPs(with fuence≥130 ***)is 2.85±*** energy distribution of FRB 121102 can be well fitted by a smooth broken power-law *** the bursts of FRB 121102 above the break energy(1.22×10^(37)erg),the best-ftting slope is 2.90^(+0.55)_(-0344),similar to the index of GPs at the same observing frequency(~1.4 GHz).We further discuss the physical origin of the repeating FRB 121102 in the framework of the super GPs *** we find that the super GPs model involving a millisecond pulsar is workable and favored for explaining FRB 121102 despite that the magnetar burst model is more popular.

关键词： pulsars radio sources general-methods:statistical