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A quark nova in the wake of a core-collapse supernova:a unifying model for long duration gamma-ray bursts and fast radio bursts

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Research in Astronomy and Astrophysics 2020年第2期20卷 119-186页

作者： Rachid Ouyed denis Leahy Nico Koning Department of Physics and Astronomy University of Calgary

By appealing to a quark nova(QN;the explosive transition of a neutron star to a quark star) in the wake of a core-collapse supernova(CCSN) explosion of a massive star,we develop a unified model for long duration gamma-ray bursts(LGRBs) and fast radio bursts(FRBs).The time delay(years to decades)between the SN and the QN,and the fragmented nature(i.e.,millions of chunks) of the relativistic QN ejecta are key to yielding a robust LGRB *** our model,an LGRB light curve exhibits the interaction of the fragmented QN ejecta with turbulent(i.e.,filamentary and magnetically saturated) SN ejecta which is shaped by its interaction with an underlying pulsar wind nebula(PWN).The afterglow is due to the interaction of the QN chunks,exiting the SN ejecta,with the surrounding *** model can fit BAT/XRT prompt and afterglow light curves simultaneously with their spectra,thus yielding the observed properties of LGRBs(e.g.,the Band function and the X-ray flares).We find that the peak luminositypeak photon energy relationship(i.e.,the Yonetoku law),and the isotropic energy-peak photon energy relationship(i.e.,the Amati law) are not fundamental but ***-like emission in our model results from coherent synchrotron emission(CSE) when the QN chunks interact with non-turbulent weakly magnetized PWN-SN ejecta,where conditions are prone to the Weibel *** field amplification induced by the Weibel instability in the shocked chunk frame sets the bunching length for electrons and pairs to radiate *** resulting emission frequency,luminosity and duration in our model are consistent with FRB *** find a natural unification of high-energy burst phenomena from FRBs(i.e.,those connected to CCSNe) to LGRBs including X-ray flashes(XRFs) and X-ray rich GRBs(XRR-GRBs) as well as superluminous SNe(SLSNe).We find a possible connection between ultra-high energy cosmic rays and FRBs and propose that a QN following a binary neutron star merger can yiel

关键词： stars:neutron stars:quark pulsars:general supernovae:general gamma-ray burst:general fast radio burst:general

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爱神的诞生！被神话选中的海滨小城

环球人文地理 2024年第15期 144-152页

作者：刘梦缘 kirill_makarov Serg Zastavkin denis Gladkiy DedMityay dudlajzov Alexanderkonsta Anatoliy Sadovskiy Lisichkin Grispb Lukas 摄图网

走进帕福斯，仿佛穿越时光隧道，来到古希腊与罗马帝国的辉煌时代，听见爱神阿芙洛狄忒的低语。在塞浦路斯西南部，距离利马索尔港口约50公里处，隐藏着一座古老的海滨小城——帕福斯（Paphos）。希腊神话中，塞浦路斯国王皮格马利翁不...

走进帕福斯，仿佛穿越时光隧道，来到古希腊与罗马帝国的辉煌时代，听见爱神阿芙洛狄忒的低语。在塞浦路斯西南部，距离利马索尔港口约50公里处，隐藏着一座古老的海滨小城——帕福斯（Paphos）。希腊神话中，塞浦路斯国王皮格马利翁不爱凡间女子，独爱由自己雕刻的象牙少女像，并如同对待真人那样，每日为象牙少女沐浴更衣。爱神阿芙洛狄忒（维纳斯）被国王的真情打动，赋予了雕像生命，让他们结为夫妻。国王和象牙少女生下的孩子叫做帕福斯，而专门供奉爱神阿芙洛狄忒的城市，也命名为帕福斯。

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Melatonin, circadian rhythms and glaucoma: current perspective

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Neural Regeneration Research 2022年第8期17卷 1759-1760页

作者： denis Gubin Dietmar Weinert Chronobiology&Chronomedicine Laboratory Medical UniversityTyumen/Department of BiologyMedical UniversityTyumen/Tyumen Cardiology Research CenterTomsk National Research Medical CenterRussian Academy of ScienceTomskRussia Institute of Biology/Zoology Martin Luther UniversityHalle-WittenbergGermany

Primary open-angle glaucoma as a causal factor for circadian disruption:Living by the clock,in alignment with external time cues is an important condition for human health and *** changes in the ambient light serve as a key factor to synchronize the endogenously generated circadian *** retina perceives the photic signals and transmits them to the central body clock,the suprachiasmatic nuclei(SCN),via the retinohypothalamic tract.

关键词： ambient alignment Periodic

Thermogravimetric analysis and kinetic modeling of the co-pyrolysis of a bituminous coal and poplar wood

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Chinese Journal of Chemical Engineering 2023年第6期58卷 53-68页

作者： Wei Wang Romain Lemaire Ammar Bensakhria denis Luart Department of Mechanical Engineering École de technologie supérieureMontrealQuebec H3C 1K3Canada Universitéde Technologie de Compiègne Centre de recherche de RoyallieuEA 4297-TIMRBP2052960205 CompiègneFrance École Supérieure de Chimie Organique et Minérale 1 Rue du Réseau Jean-Marie Buckmaster60200 CompiègneFrance

The co-pyrolysis of coal and biomass has proven to be a promising route to produce liquid and gaseous fuels as well as specific value-added chemicals while contributing to mitigating CO_(2) *** interactions between the co-processed feedstocks,however,need to be elucidated to support the development of such a thermochemical conversion *** this context,the present work covers the kinetic analysis of the co-pyrolysis of a bituminous coal with poplar *** this research,biomass was blended with coal at two different mass ratios(10%(mass)and 20%(mass)).Thermogravimetric analyses were carried out with pure and blended samples at four heating rates(5,10,15 and 30℃·min^(-1)).A direct comparison of experimental and theoretical results(based on a simple additivity rule)failed to yield a clear-cut conclusion regarding the existence of synergistic *** analyses have therefore been achieved using two model-free methods(the Ozawa-Flynn-Wall and Kissinger-Akahira-Sunose models)to estimate the rate constant parameters related to the pyrolysis process.A significant decrease of the activation energy has thus been observed when adding wood to coal(activation energies associated with the blend containing 20%(mass)of biomass being even lower than those estimated for pure wood at low conversion degrees).This trend was attributed to the possible presence of synergies whose related mechanisms are *** rate constant parameters derived by means of the two tested models were finally used to simulate the evolution of the conversion degree of each sample as a function of the temperature,thus leading to a satisfying agreement between measured and simulated data.

关键词： Co-pyrolysis Coal Wood Kinetics Synergistic effects

Hints of a second explosion(a quark nova) in Cassiopeia A supernova

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Research in Astronomy and Astrophysics 2015年第4期15卷 483-500页

作者： Rachid Ouyed denis Leahy Nico Koning Department of Physics and Astronomy University of Calgary

We show that the explosive transition of the neutron star （NS） to a quark star （QS）（a Quark Nova） in Cassiopeia A （Cas A） a few days following the supernova （SN） proper can account for several of the puzzling kinematic and nucleosynthetic features that are observed. The observed decoupling between Fe and 44Ti and the lack of Fe emission within 44Ti regions is expected in the QN model owing to the spallation of the inner SN ejecta by relativistic QN neutrons. Our model predicts the 44Ti to be more prominent to the NW of the central compact object （CCO） than in the SE and little of it along the NE-SW jets, in agreement with NuStar observations. Other intriguing features of Cas A are addressed, such as the lack of a pulsar wind nebula and the reported few percent drop in the CCO temperature over a period of 10 yr.

关键词： ISM: individual object (Cassiopeia A) -- ISM: supemova remnants --stars: neutron

Polarization in cyclotron radiation in strong magnetic fields

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Research in Astronomy and Astrophysics 2010年第10期10卷 1023-1040页

作者： Luidmila Semionova denis Leahy Jorge Paez Department of Physics Universidad National Department of Physics and Astronomy University of CalgaryA Space Research Center University of Costa Rica

We revisit the problem of radiative transitions of electrons in the presence of a strong magnetic field. We derive fully relativistic cyclotron transition rates for an arbitrary magnetic field, for any orientation of electron spin and for any polarization of the emitted radiation. Also, we obtain the transition rates for any value of the initial electron＇s parallel momentum. For very strong magnetic fields, transitions to the ground state predominate. Transition rates summed over the electron＇s spin orientation and for unpolarized radiation are also obtained, which confirm previous results by Latal. Transition widths are calculated for different electron spin orientations and different polarizations of radiation. We obtain general expressions for transition rates that reduce to the results for the non-relativistic case and for unpolarized radiation. Additionally we get, for the non-relativistic approximation, the transition rates for any polarization of radiation. As an application, the first five emission lines are evaluated and compared to the X-ray emitting neutron star V0332＋53, which has multiple observable cyclotron lines, taking into account gravitational redshift. The most probable polarization is ε（2）.

关键词： stars neutron -- radiation mechanisms non-thermal -- stars magneticfields -- polarization

Relaxor behaviour and phase transition of perovskite ferroelectrics-type complex oxides(1–x)Na_(0.5)Bi_(0.5)TiO_3–xCaTiO_3 system

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Journal of Advanced Ceramics 2018年第2期7卷 124-142页

作者： Roy ROUKOS Nissrine ZAITER denis CHAUMONT Laboratoire Interdisciplinaire Carnot de Bourgogne UMR 6303 CNRS Université de Bourgogne

Polycrystalline powders of (1–x)Na_(0.5)Bi_(0.5)TiO_3–xCaTiO_3 ((1–x)NBT–xCT, 0 ≤ x ≤ 0.55) have been synthesized by solid state route. The effects of simultaneous substitution of Na^+/Bi^(3+) at A-site in NBT on structural and dielectric properties were investigated. X-ray diffraction analysis revealed the phase transition from rhombohedral structure(x = 0) to orthorhombic structure(x ≥0.15). A distinct behaviour in dielectric properties was obtained, where for x = 0, a normal ferroelectric behaviour was observed, whereas for x ≥ 0.15, a broad dielectric anomaly was revealed such that the maximum temperature(T_m) strongly depended on the frequency and shifted towards low temperature with CT. The dielectric dispersion indicated a relaxor behaviour revealed by the degree of diffuseness and modelled via Vogel–Fulcher relation. The study highlighted the relaxor behaviour as a function of frequency and proved the transformation from a relaxor high-frequency dependence to a paraelectric phase at temperature T_s. The distinct variation of the Raman spectra at room temperature was correlated with X-ray diffraction results and proved the already mentioned transition. On heating(-193–500 ℃), the Raman spectra confirmed the structural stability(Pnma) of the materials. The phonon behaviour for x = 0.15 was discussed in terms of the appearance of polar nanoregions(PNRs) into a non-polar orthorhombic matrix responsible of the relaxor behaviour. For x = 0.20, unchanged phonon behaviour confirmed the variation in dielectric behaviour where the solids transformed from a relaxor to a paraelectric state without structural phase transition.

关键词： relaxor behaviour dielectric properties Vogel–Fulcher relationship polar nanoregions (PNRs) X-ray diffraction Raman spectroscopy

Situational interest impacts college students’physical activity in a design-based bike exergame

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Journal of Sport and Health Science 2022年第2期11卷 172-178,I0002页

作者： denis Pasco Cédric Roure School of Education University of Bourgogne Franche-ComtéBesan¸con 25000France Teaching and Research Unit in Physical Education and Sport University of Teacher EducationLausanne 1014Switzerland

Background:Active videogames or exergames have been used as an innovative way to promote physical activity(PA)among various populations.A player’s interest in active videogames is associated with the fun and entertaining nature of the games and may trigger situational interest,thus increasing *** goal of this study was to examine the impact of situational interest dimensions on college students’PA when playing the design-based bike exergame Greedy Rabbit(Vescape,Berlin,Germany).Methods:Sixty undergraduate students(age:20.8±1.3 years,mean±SD,18-25 years old;51.7%males)were recruited from the kinesiology department of a university located in the southern region of *** participants were assigned to an experimental group(n=41)or a control group(n=19)based on an incremental cycling *** in the experimental group engaged in 1 session of Greedy Rabbit(Vescape)while students in the control group engaged in 1 session of a placebo version of Greedy Rabbit(Vescape).The length of the sessions ranged from 24 min to 31 ***:Results for the control group indicated that the players’PA metrics(cadence:F(19,360)=1.43,p=0.11;heart rate:F(19.360)=1.16,p=0.29;oxygen consumption:F(19,360)=0.83,p=0.67)were stable during the *** for the experimental group demonstrated the effects of time on the players’PA metrics and revealed significant associations between the change in the players’situational interest dimensions and PA metrics(cadence:F(19,800)=26.30,p<0.01;heart rate:F(19,800)=19.77,p<0.01;oxygen consumption:F(19,800)=10.04,p<0.01).Conclusion:An approach using a design-based exergame may be a relevant strategy for promoting levels of PA that yields positive health-related outcomes among college students.

关键词： Active videogame College students Exergame Physical activity Situational interest

SN 2009ip and SN 2010mc as dual-shock Quark-Novae

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Research in Astronomy and Astrophysics 2013年第12期13卷 1463-1470页

作者： Rachid Ouyed Nico Koning denis Leahy Department of Physics and Astronomy University of Calgary 2500 University Drive NW

In recent years a number of double-humped supernovae （SNe） have been discovered. This is a feature predicted by the dual-shock Quark-Nova （QN） model where an SN explosion is followed （a few days to a few weeks later） by a QN explo- sion. SN 2009ip and SN 2010mc are the best observed examples of double-humped SNe. Here, we show that the dual-shock QN model naturally explains their light curves including the late time emission, which we attribute to the interaction between the mixed SN and QN ejecta and the surrounding circumstellar matter. Our model applies to any star （O-stars, luminous blue variables, Wolf-Rayet stars, etc.） provided that the mass involved in the SN explosion is ~ 20 Mo which provides good conditions for forming a QN.

关键词： circumstellar matter -- stars: evolution -- stars: winds outflows --supernovae: general -- supernovae: individual (SN 2009ip SN 2010mc)