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A Simulation of the Dependence of Tidal Interaction on Galaxy Type in Compact Groups
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作者 Mark J. Henriksen Mateo Mejia 《International Journal of Astronomy and Astrophysics》 2024年第2期85-100,共16页
We have investigated the role that different galaxy types have in galaxy-galaxy interactions in compact groups. N-body simulations of 6 galaxies consisting of a differing mixture of galaxy types were run to compare th... We have investigated the role that different galaxy types have in galaxy-galaxy interactions in compact groups. N-body simulations of 6 galaxies consisting of a differing mixture of galaxy types were run to compare the relative importance of galaxy population demographic on evolution. Three different groups with differing galaxy content were tested: all spiral, a single elliptical and 50% elliptical. Tidal interaction strength and duration were recorded to assess the importance of an interaction. A group with an equal number of spiral and elliptical galaxies has some of the longest and strongest interactions with elliptical-elliptical interactions being most significant. These elliptical-elliptical interactions are not dominated by a single large event but consist of multiple interactions. Elliptical galaxies tidally interacting with spiral galaxies, have the next strongest interaction events. For the case when a group only has a single elliptical, the largest magnitude tidal interaction is an elliptical on a spiral. Spirals interact with each other through many small interactions. For a spiral only group, the interactions are the weakest compared to the other group types. These spiral interactions are not dominated by any singular event that might be expected to lead to a merger but are more of an ongoing harassment. These results suggest that within a compact group, early type galaxies will not form via merger out of an assemblage of spiral galaxies but rather that compact groups, in effect form around an early type galaxy. 展开更多
关键词 galaxy Groups galaxy Clusters galaxy Evolution N-Body Simulations
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Solving the Conundrum of Dark Matter and Dark Energy in Galaxy Clusters
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作者 Manuel Abarca 《Journal of High Energy Physics, Gravitation and Cosmology》 CAS 2024年第4期1785-1805,共21页
This paper develops the Dark Matter by Quantum Gravitation theory, DMbQG theory hereafter, in clusters of galaxies in the cosmologic model ΛCDM of the Universe. Originally this theory was developed by the author for ... This paper develops the Dark Matter by Quantum Gravitation theory, DMbQG theory hereafter, in clusters of galaxies in the cosmologic model ΛCDM of the Universe. Originally this theory was developed by the author for galaxies, especially using MW and M31 rotation curves. An important result got by the DMbQG theory is that the total mass associated to a galactic halo depend on the square root of radius, being its dominion unbounded. Apparently, this result would be absurd because of divergence of the total mass. As the DE is negligible at galactic scale, it is needed to extend the theory to clusters in order to study the capacity of DE to counterbalance to DM. Thanks this property, the DMbQG theory finds unexpected theoretical results. In this work, it is defined, the total mass as baryonic matter plus DM and the gravitating mass as the addition of the total mass plus the negative mass associated to dark energy. In clusters it is defined the zero gravity radius (RZG hereafter) as the radius needed by the dark energy to counterbalance the total mass. It has been found that the ratio RZG/RVIRIAL ≈ 7.3 and its Total mass associated at RZG is ≈2.7 MVIRIAL. In addition, it has been calculated that the sphere with the extended halo radius RE = 1.85 RZG has a ratio DM density versus DE density equal to 3/7 and its total mass associated at RE is ≈3.6 MVIRIAL. This works postulates that the factor 3.6 may equilibrate perfectly the strong imbalance between the Local mater density parameter (0.08) versus the current Global matter density one (0.3). Currently, this fact is a big conundrum in cosmology, see chapter 7. Also it has been found that the zero velocity radius, RZV hereafter, i.e. the cluster border because of the Hubble flow, is ≈0.6 RZG and its gravitating mass is ≈ 1.5 MVIR. By derivation of gravitating mass function, it is calculated that at 0.49 RZG, this function reaches its maximum whose value is ≈1.57 MVIR. Throughout the paper, some of these results have been validated with recent data published for the Virgo cluster. As Virgo is the nearest big cluster, it is the perfect benchmark to validate any new theory about DM and DE. These new theoretical findings offer to scientific community a wide number of tests to validate or reject the theory. The validation of DMbQG theory would mean to know the nature of DM that at the present, it is an important challenge for the astrophysics science. 展开更多
关键词 Dark Matter Dark Energy galaxy Clusters Quantum Gravitation
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迈进Galaxy AI新时代,三星Galaxy S24系列正式发布
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《计算机应用文摘》 2024年第4期133-135,共3页
2024年1月18日,三星电子正式发布了新一代高端旗舰系列产品,包括三星GalaxyS24Ultra、Galaxy S24+和Galaxy S24。通过引入创新的GalaxyAI,新一代三星Galaxy S系列将重新定义移动设备,为用户提供更强大的功能,开启全新的移动体验时代。... 2024年1月18日,三星电子正式发布了新一代高端旗舰系列产品,包括三星GalaxyS24Ultra、Galaxy S24+和Galaxy S24。通过引入创新的GalaxyAI,新一代三星Galaxy S系列将重新定义移动设备,为用户提供更强大的功能,开启全新的移动体验时代。这一系列产品将利用智能文本和通话翻译等功能,实现无障碍交流;采用Galaxy超视觉影像释放用户创意;以全新的搜索方式助力Galaxy用户更好地探索世界。三星GalaxyS24系列将充分发挥人工智能的优势,全面提升用户的移动体验。 展开更多
关键词 移动设备 S24 galaxy 三星电子 人工智能 视觉影像 搜索方式 AI
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三星Galaxy Z Fold6/Z Flip6成都品鉴会:体验智慧AI“星”生活
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《计算机应用文摘》 2024年第18期208-209,共2页
8月21日,三星Galaxy新品媒体品鉴会在成都举行。本次品鉴会上,三星带来了旗下最新的第6代折叠屏手机Galaxy Z Fold6和Galaxy Z Flip6,以及三星智能穿戴设备Galaxy Ring,Galaxy Watch Ultra,Galaxy Watch7与Galaxy Buds3系列。这些产品... 8月21日,三星Galaxy新品媒体品鉴会在成都举行。本次品鉴会上,三星带来了旗下最新的第6代折叠屏手机Galaxy Z Fold6和Galaxy Z Flip6,以及三星智能穿戴设备Galaxy Ring,Galaxy Watch Ultra,Galaxy Watch7与Galaxy Buds3系列。这些产品不仅展示了三星对Galaxy AI的最新探索成果,将AI赋能到Galaxy新品后还会为人们提供更便捷、智能、高效的生活新体验。 展开更多
关键词 galaxy 品鉴会 智能穿戴设备 AI 三星 探索成果 新体验
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三星Galaxy S24系列中国发布,Galaxy AI塑造智能手机新体验
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《计算机应用文摘》 2024年第5期128-130,共3页
2024年1月25日,三星电子面向中国市场正式发布了新一代高端旗舰智能手机一—三星Galaxy S24系列,包括3款产品:三星GalaxyS24Ultra、Galaxy S24+和Galaxy S24。通过引人创新的Galaxy AI技术,三星Galaxy S24系列将人工智能优势融入智能手机。
关键词 智能手机 S24 三星电子 galaxy 人工智能 AI技术 新体验 发布
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HI in High Gas-phase Metallicity Dwarf Galaxy WISEA J230615.06+143927.9
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作者 Yan Guo C.Sengupta +2 位作者 T.C.Scott P.Lagos Y.Luo 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2024年第1期292-299,共8页
We present resolved Giant Metrewave Radio Telescope H I observations of the high gas-phase metallicity dwarf galaxy WISEA J230615.06+143927.9(z = 0.005)(hereafter J2306) and investigate whether it could be a Tidal Dwa... We present resolved Giant Metrewave Radio Telescope H I observations of the high gas-phase metallicity dwarf galaxy WISEA J230615.06+143927.9(z = 0.005)(hereafter J2306) and investigate whether it could be a Tidal Dwarf Galaxy(TDG) candidate. TDGs are observed to have higher metallicities than normal dwarfs. J2306 has an unusual combination of a blue g-r color of 0.23 mag, irregular optical morphology and high-metallicity(12 +log(O/H) = 8.68 ± 0.14), making it an interesting galaxy to study in more detail. We find J2306 to be an H I rich galaxy with a large extended, unperturbed rotating H I disk. Using our H I data we estimated its dynamical mass and found the galaxy to be dark matter(DM) dominated within its H I radius. The quantity of DM, inferred from its dynamical mass, appears to rule out J2306 as an evolved TDG. A wide area environment search reveals J2306 to be isolated from any larger galaxies which could have been the source of its high gas metallicity. Additionally, the H I morphology and kinematics of the galaxy show no indication of a recent merger to explain the high-metallicity.Further detailed optical spectroscopic observations of J2306 might provide an answer to how a seemingly ordinary irregular dwarf galaxy achieved such a high level of metal enrichment. 展开更多
关键词 galaxies:abundances galaxies:dwarf galaxies:irregular radio lines:galaxies radio lines:ISM
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A Possible X-ray Quasi-periodic Oscillation in the Narrow-line Seyfert 1 Galaxy Mrk 142
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作者 Xiao-Gu Zhong Jian-Cheng Wang +1 位作者 Yong-Yun Chen Xiao-Ling Yu 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2024年第6期191-200,共10页
A possible quasi-periodic oscillation(QPO) at frequency 7.045 × 10^(-5) Hz is found in the narrow-line Seyfert 1galaxy Mrk 142 in the data of XMM-Newton collected on 2020 April 11.We find that the QPO signal is s... A possible quasi-periodic oscillation(QPO) at frequency 7.045 × 10^(-5) Hz is found in the narrow-line Seyfert 1galaxy Mrk 142 in the data of XMM-Newton collected on 2020 April 11.We find that the QPO signal is statistically significantly larger than the 5σ level and highly coherent with quality factor Q > 5 at the 0.3–10 keV band by using the method of the Lomb–Scargle Periodogram,the Weighted Wavelet Z-transform and the REDFIT.We analyze the data in 0.3–0.6 keV,0.6–1 keV,1–3 keV and 3–10 keV energy bands,and find obvious QPO signals at 0.3–0.6 keV and 1–3 keV bands.We then analyze the time-average spectra and time variability at the QPO frequency of 7.045 × 10^(-5) Hz,and use a model to fit them.We find that the QPO signal mainly comes from the X-ray hot corona. 展开更多
关键词 X-rays:galaxies galaxies:Seyfert ACCRETION accretion disks radiation mechanisms:general
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Long Term X-Ray Spectral Variations of the Seyfert-1 Galaxy Mrk 279
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作者 K.Akhila Ranjeev Misra +1 位作者 Savithri H.Ezhikode K.Jeena 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2024年第6期307-314,共8页
We present the results from a long term X-ray analysis of Mrk 279 during the period 2018–2020.We use data from multiple missions–AstroSat,NuSTAR and XMM-Newton,for the purpose.The X-ray spectrum can be modeled as a ... We present the results from a long term X-ray analysis of Mrk 279 during the period 2018–2020.We use data from multiple missions–AstroSat,NuSTAR and XMM-Newton,for the purpose.The X-ray spectrum can be modeled as a double Comptonization along with the presence of neutral Fe Kαline emission,at all epochs.We determined the source’s X-ray flux and luminosity at these different epochs.We find significant variations in the source’s flux state.We also investigate the variations in the source’s spectral components during the observation period.We find that the photon index and hence the spectral shape follow the variations only over longer time periods.We probe the correlations between fluxes of different bands and their photon indices,and found no significant correlations between the parameters. 展开更多
关键词 galaxies:Seyfert galaxies:individual(Mrk 335) X-rays:galaxies
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New HⅠObservations Toward the NGC 5055 Galaxy Group with FAST
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作者 Xiao-Lan Liu Ming Zhu +5 位作者 Jin-Long Xu Peng Jiang Chuan-Peng Zhang Nai-Ping Yu Jun-Jie Wang Yan-Bin Yang 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2024年第7期249-256,共8页
We report a new high-sensitivity HⅠmapping observation of the NGC 5055 galaxy group over an area of 1°.5×0°.75 with the Five-hundred-meter Aperture Spherical radio Telescope(FAST).Our observation revea... We report a new high-sensitivity HⅠmapping observation of the NGC 5055 galaxy group over an area of 1°.5×0°.75 with the Five-hundred-meter Aperture Spherical radio Telescope(FAST).Our observation reveals that the warped HⅠdisk of NGC 5055 is more extended than what was previously observed by WSRT,out to239(61.7 kpc).The total HⅠmass of NGC 5055 is determined to be~1.1×10^(10)M_Θ.We identified three HⅠclouds with HⅠmasses of the order of~10^(7)M_Θat the southeastern edge of the HⅠdisk,as well as a candidate high-velocity cloud with an HⅠmass of(1.2±0.5)×10^(6)M_Θto the north of NGC 5055.The HⅠcontent of UGCA337 is robustly detected for the first time by the FAST observations.It has a narrow HⅠlinewidth of W_(50)=17.4±3.8 km s^(-1)with a total HⅠmass of(3.5±0.3)×10^(6)M_Θ.Comparing the gas content and g-r color of UGCA 337 with typical low-mass dwarf galaxies,UGCA 337 appears relatively gas-poor despite its blue color.This suggests that UGCA 337 may have undergone gas stripping in the past.We also analyzed the possible origin of the diffuse HⅠclouds located at the outskirts of NGC 5055,and speculate that they might be the remnant features of a merger event in the past. 展开更多
关键词 GALAXIES evolution-galaxies structure-galaxies individual(NGC 5055)-galaxies kinematics and dynamics-galaxies INTERACTIONS
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A Monte Carlo Study of the Evolution of the Scale Height of Normal Pulsars in the Galaxy 被引量:1
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作者 Ying-Chun Wei Xin-Ji Wu +2 位作者 Qiu-He Peng Na Wang Jin Zhang 《Chinese Journal of Astronomy and Astrophysics》 CSCD 2005年第6期610-618,共9页
Based on the undisturbed, finite thickness disk gravitational potential, we carried out 3-D Monte Carlo simulations of normal pulsars. We find that their scale height evolves in a similar way for different velocity di... Based on the undisturbed, finite thickness disk gravitational potential, we carried out 3-D Monte Carlo simulations of normal pulsars. We find that their scale height evolves in a similar way for different velocity dispersions (δv): it first increases linearly with time, reaches a peak, then gradually decreases, and finally approaches a stable asymptotic value. The initial velocity dispersion has a very large influence on the scale height. The time evolution of the scale height is studied. When the magnetic decay age is used as the time variable, the observed scale height has a similar trend as the simulated results in the linear stage, from which we derive velocity dispersions in the range 70 - 178km s^-1, which are near the statistical result of 90 - 270km s^-1 for 92 pulsars with known transverse velocities. If the characteristic age is used as the time variable, then the observed and theoretical curves roughly agree for t 〉 10^8 yr only if av 〈 25km s^-1. 展开更多
关键词 pulsar general - stars evolution - galaxy structure - galaxy DISK
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Measurement of the Dark Matter Velocity Dispersion with Galaxy Stellar Masses, UV Luminosities, and Reionization 被引量:1
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作者 Bruce Hoeneisen 《International Journal of Astronomy and Astrophysics》 2022年第3期258-272,共15页
The root-mean-square of non-relativistic warm dark matter particle velocities scales as v<sub>hrms</sub>(a)=v<sub>hrms</sub>(1)/a , where a is the expansion parameter of the universe. This velo... The root-mean-square of non-relativistic warm dark matter particle velocities scales as v<sub>hrms</sub>(a)=v<sub>hrms</sub>(1)/a , where a is the expansion parameter of the universe. This velocity dispersion results in a cut-off of the power spectrum of density fluctuations due to dark matter free-streaming. Let k<sub>fs </sub>(t<sub>eq</sub>) be the free-streaming comoving cut-off wavenumber at the time of equal densities of radiation and matter. We obtain , and , at 68% confidence, from the observed distributions of galaxy stellar masses and rest frame ultra-violet luminosities. This result is consistent with reionization. From the velocity dispersion cut-off mass we obtain the limits v<sub>hrms</sub>(1)k<sub>fs </sub>(t<sub>eq</sub>) >1.5 Mpc<sup>-1</sup>. These results are in agreement with previous measurements based on spiral galaxy rotation curves, and on the formation of first galaxies and reionization. These measured parameters determine the temperature-to-mass ratio of warm dark matter. This ratio happens to be in agreement with the no freeze-in and no freeze-out warm dark matter scenario of spin 0 dark matter particles decoupling early on from the standard model sector. Spin 1/2 and spin 1 dark matter are disfavored if nature has chosen the no freeze-in and no freeze-out scenario. An extension of the standard model of quarks and leptons, with scalar dark matter that couples to the Higgs boson that is in agreement with all current measurements, is briefly reviewed. Discrepancies with limits on dark matter particle mass that can be found in the literature are addressed. 展开更多
关键词 Warm Dark Matter galaxy Stellar Mass galaxy UV Luminosity REIONIZATION
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Segments of spiral arms of the Galaxy traced by classical Cepheids:effects of age heterogeneity
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作者 Angelina V.Veselova Igor’I.Nikiforov 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2020年第12期357-366,共10页
We investigated the dependence of the parameters of the segments of spiral arms of the Galaxy on the age of classical Cepheids.The catalog of Cepheids(Mel’nik et al.)was divided into two samples—relatively young(P&g... We investigated the dependence of the parameters of the segments of spiral arms of the Galaxy on the age of classical Cepheids.The catalog of Cepheids(Mel’nik et al.)was divided into two samples—relatively young(P>9d)and relatively old(P<9d)objects.The parameters of the spiral structure were determined both for two samples separately and jointly for the combination of two systems of segments traced by young and old objects.For most of the segments,their parameters for young and old objects differ significantly.Taking into account the difference between the two segment systems,we obtained the estimate R0 equal to 7.23^+0.19/-0.18 kpc,which in the modern Large Magellanic Cloud(LMC)calibration corresponds to the value of R0=8.08^+0.2/-10.20|stat.^+0.38/-0.36|cal.kpc.It is shown that the displacement between the segments is not reduced to the effect of differential rotation only.To interpret this displacement for objects of Perseus and Sagittarius-2 segments,we carried out a dynamic modeling of the change in the position of the segment points when moving in the smooth gravitational field of the Galaxy.At the angular velocity of rotation of the spiral pattern Ωp=25.2±0.5 km s 1 kpc 1(Dambis et al.)the observed displacement between segments on young and old objects can be explained by the amplitude of spiral perturbations of the radial velocity of u=10±1.5 km s 1.For the constructed double system of spiral segments,it is demonstrated that the assumption of constancy of the pitch angles within each segment and the assumption that the pole of the spiral pattern is in the direction of the nominal center of the Galaxy do not contradict the data within the range of uncertainty. 展开更多
关键词 galaxy:fundamental parameters galaxy:structure
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Galaxy Inmarsat—C/GPS TNL7001型C站的主要功能
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作者 高音 《航海技术》 1997年第3期33-35,共3页
本文对Inmarsat-C站的特点进行了说明,并着重阐述了Galaxy Inmar-sat-C/GPS TNL7001型C站电报模式的船位报告和查询功能。
关键词 galaxy Inmarsat-C站 通信 导航 船站 岸站 功能
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A Unifying Theory of Dark Energy, Dark Matter, and Baryonic Matter in the Positive-Negative Mass Universe Pair: Protogalaxy and Galaxy Evolutions
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作者 Ding-Yu Chung 《Journal of Modern Physics》 2020年第7期1091-1122,共32页
This paper modifies the Farnes’ unifying theory of dark energy and dark matter which are negative-mass, created continuously from the negative-mass universe in the positive-negative mass universe pair. The first modi... This paper modifies the Farnes’ unifying theory of dark energy and dark matter which are negative-mass, created continuously from the negative-mass universe in the positive-negative mass universe pair. The first modification explains that observed dark energy is 68.6%, greater than 50% for the symmetrical positive-negative mass universe pair. This paper starts with the proposed positive-negative-mass 11D universe pair (without kinetic energy) which is transformed into the positive-negative mass 10D universe pair and the external dual gravities as in the Randall-Sundrum model, resulting in the four equal and separate universes consisting of the positive-mass 10D universe, the positive-mass massive external gravity, the negative-mass 10D universe and the negative-mass massive external gravity. The positive-mass 10D universe is transformed into 4D universe (home universe) with kinetic energy through the inflation and the Big Bang to create positive-mass dark matter which is five times of positive-mass baryonic matter. The other three universes without kinetic energy oscillate between 10D and 10D through 4D, resulting in the hidden universes when D > 4 and dark energy when D = 4, which is created continuously to our 4D home universe with the maximum dark energy = 3/4 = 75%. In the second modification to explain dark matter in the CMB, dark matter initially is not repulsive. The condensed baryonic gas at the critical surface density induces dark matter repulsive force to transform dark matter in the region into repulsive dark matter repulsing one another. The calculated percentages of dark energy, dark matter, and baryonic matter are 68.6 (as an input from the observation), 26 and 5.2, respectively, in agreement with observed 68.6, 26.5 and 4.9, respectively, and dark energy started in 4.33 billion years ago in agreement with the observed 4.71 <span style="white-space:nowrap;">&plusmn;</span> 0.98 billion years ago. In conclusion, the modified Farnes’ unifying theory reinterprets the Farnes’ equations, and is a unifying theory of dark energy, dark matter, and baryonic matter in the positive-negative mass universe pair. The unifying theory explains protogalaxy and galaxy evolutions in agreement with the observations. 展开更多
关键词 Unifying Theory Farnes Dark Energy Dark Matter Baryonic Matter Negative Mass Positive-Negative Mass Universe Pair Protogalaxy Evolution galaxy Evolution
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放逐自己 三星GALAXYS4千里随行
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作者 陈芷若 《移动信息》 2013年第8期8-9,共2页
当你行走在路上,丰富的阅历会沉淀你的气质,开阔的眼界会拓展你的心胸,你的世界就是无垠的蓝天和广豪的大地。——要么读书,要么旅行,身体和灵魂,必须有一个在路上。
关键词 三星集团 galaxyS4 手机 移动通信
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Galaxy Ⅱ:完美的钢琴音色库 被引量:2
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作者 付佳音 《演艺设备与科技》 2008年第S1期38-40,共3页
本文介绍了Galaxy公司开发的一款新的钢琴音色库的特点。
关键词 galaxy 钢琴音色库 控制器 效果器
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The Principle of Equivalence: Periastron Precession, Light Deflection, Binary Star Decay, Graviton Temperature, Dark Matter, Dark Energy and Galaxy Rotation Curves 被引量:3
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作者 F. J. Oliveira 《Journal of High Energy Physics, Gravitation and Cosmology》 2021年第2期661-679,共19页
The nature of the principle of equivalence is explored. The path of gravitons is analyzed in an accelerating system equivalent to a gravitating system. The finite speed of the graviton results in a delay of the gravit... The nature of the principle of equivalence is explored. The path of gravitons is analyzed in an accelerating system equivalent to a gravitating system. The finite speed of the graviton results in a delay of the gravitational interaction with a particle mass. From the aberration found in the path of the graviton we derive the standard expression for the advancement of the periastron of the orbit of the mass around a star. In a similar way, by analysing the aberrations of the graviton and light paths in an accelerating reference frame, the expression for the deflection of light by a massive body is obtained identically to the standard result. We also examine the binary star system and calculate the decay in its orbital period. The decay is attributed to the redshift of the graviton frequency relative to the accelerating system. Here too, we obtain good agreement with experimental measurements. Also, hypothesizing that gravitons behave like photons, we determine the temperature of the gravitons in a binary star system and form the Bose-Einstein distribution. Finally, we show how the redshift of gravitons may be the source of dark matter, dark energy and flat line spiral galaxy rotation curves. 展开更多
关键词 GRAVITONS Binary Stars galaxy Rotations Dark Matter Dark Energy
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Distributions of Neutron Exposures in AGB Stars and the Galaxy 被引量:3
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作者 Wen-Yuan Cui Feng-Hua Zhang +2 位作者 Wei-Juan Zhang Lu Zhang Bo Zhang 《Chinese Journal of Astronomy and Astrophysics》 CSCD 2007年第2期224-234,共11页
Based on the s-process nucleosynthesis model with the 13C(α, n)16O reaction occurring under radiative conditions in the interpulse phases, we investigate the characteristics of the distribution of neutron exposure ... Based on the s-process nucleosynthesis model with the 13C(α, n)16O reaction occurring under radiative conditions in the interpulse phases, we investigate the characteristics of the distribution of neutron exposure in low-mass Asymptotic Giant Branch (AGB) stars. We introduce a new concept, the distribution of neutron exposures of the Galaxy (NEG), to study the chemical evolution characteristics of the Galaxy for s-process elements. Using a chemical evolution model of the Galaxy, we develop a model for the NEG and obtain the evolution results of the NEG in different epochs. The present results appear to reasonably reproduce the distribution of neutron exposures of the solar system (hereafter NES). The main component and the strong component in the NES are built up in different epochs. The strong component of the s-process is mainly synthesised in the low-mass and metal-poor AGB stars, and the main component is produced by the s-process in the low-mass AGB stars with higher metallicities. 展开更多
关键词 galaxy evolution- stars AGB and post-AGB- stars abundances
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The current status of galaxy formation 被引量:2
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作者 Joseph Silk Gary A.Mamon 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2012年第8期917-946,共30页
Understanding galaxy formation is one of the most pressing issues in cos- mology. We review the current status of galaxy formation from both an observational and a theoretical perspective, and summarize the prospects ... Understanding galaxy formation is one of the most pressing issues in cos- mology. We review the current status of galaxy formation from both an observational and a theoretical perspective, and summarize the prospects for future advances. 展开更多
关键词 galaxy formation -- galaxies: evolution -- galaxies: star formation --galaxies: active
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Cold or Warm Dark Matter?: A Study of Galaxy Stellar Mass Distributions 被引量:3
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作者 Bruce Hoeneisen 《International Journal of Astronomy and Astrophysics》 2020年第2期57-70,共14页
We compare the observed galaxy stellar mass distributions in the redshift range <img src="Edit_bc01f6dd-d7f9-42f9-9db0-dbd1148de50e.png" alt="" />with expectations of the cold ΛCDM and warm ... We compare the observed galaxy stellar mass distributions in the redshift range <img src="Edit_bc01f6dd-d7f9-42f9-9db0-dbd1148de50e.png" alt="" />with expectations of the cold ΛCDM and warm ΛWDM dark matter models, and obtain the warm dark matter cut-off wavenumber: <img src="Edit_ab3d491d-7145-4d59-b4b1-bea473d62333.png" alt="" />. This result is in agreement with the independent measurements with spiral galaxy rotation curves, confirms that <em>k</em><sub>fs</sub> is due to warm dark matter free-streaming, and is consistent with the scenario of dark matter with no freeze-in and no freeze-out. Detailed properties of warm dark matter can be derived from <em>k</em><sub>fs</sub>. The data disfavors the ΛCDM model. 展开更多
关键词 Dark Matter Warm Dark Matter Dark Matter Properties galaxy Stellar Mass
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