期刊文献+
共找到31篇文章
< 1 2 >
每页显示 20 50 100
Astrobiological Constraints on Astrophysics
1
作者 Charles H. McGruder III Dirk Schulze-Makuch 《Journal of Modern Physics》 2024年第11期1959-1979,共21页
Life exists in the universe and therefore the astrophysical properties of the universe must be such that they allow the origin of life. We connect astrobiology and astrophysics via one astrobiological quantity—the pr... Life exists in the universe and therefore the astrophysical properties of the universe must be such that they allow the origin of life. We connect astrobiology and astrophysics via one astrobiological quantity—the probability of the origin of life. We show how this probability, if it is very low, will allow us to answer profound astrophysical questions such as the type of universe we live in, the fate of our universe, whether neutron stars, white and brown dwarfs evaporate and whether protons decay. 展开更多
关键词 ASTROBIOLOGY astrophysICS cosmologY RELATIVITY
下载PDF
BL Lacertae objects and the extragalactic γ-ray background
2
作者 Fan Li Xin-Wu Cao 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2011年第8期879-887,共9页
A tight correlation between γ-ray and radio emission is found for a sample of BL Lacertae (BL Lac) objects detected by the Fermi Gamma-ray Space Telescope (Fermi) and the Energetic Gamma-Ray Experiment Telescope ... A tight correlation between γ-ray and radio emission is found for a sample of BL Lacertae (BL Lac) objects detected by the Fermi Gamma-ray Space Telescope (Fermi) and the Energetic Gamma-Ray Experiment Telescope (EGRET). The γ-ray emission of BL Lac objects exhibits strong variability, and the detection rate of γ-ray BL Lac objects is low, which may be related to the γ-ray duty cycle of BL Lac objects. We estimate the γ-ray duty cycle, δγ ≌ 0.11, for BL Lac objects detected by EGRET and Fermi. Using the empirical relation of γ-ray emission with radio emission and the estimated γ-ray duty cycle δγ, we derive the γ-ray luminosity function (LF) of BL Lac objects from their radio LE Our derived γ-ray LF of BL Lac objects can almost reproduce that calculated with the recently released Fermi bright active galactic nuclei (AGN) sample. Comparison of the derived LF of the γ-ray BL Lac objects in this work with that derived by Abdo et al. (2009a) requires the γ-ray duty cycle of BL Lac objects to be almost luminosity-independent. We find that - 45% of the extragalactic diffuse γ-ray background (EGRB) is contributed by BL Lac objects. Combining the estimate of the quasar contribution to the EGRB in the previous work, we find that 77% of the EGRB is contributed by BL Lac objects and radio quasars. 展开更多
关键词 GALAXIES active -- galaxies BL Lacertae objects general -- cosmology diffuse radiation -- gamma rays THEORY
下载PDF
Revealing the Uncertainty and Absolute Certainty Principles in the Kinetics of Objects Formation
3
作者 Emil Edipovich Lin 《World Journal of Mechanics》 2018年第4期82-93,共12页
The paper presents some examples revealing the uncertainty and absolute certainty principles in kinetics of objects formation that are different in their physical nature and in space scales: sub-stances of microcosm, ... The paper presents some examples revealing the uncertainty and absolute certainty principles in kinetics of objects formation that are different in their physical nature and in space scales: sub-stances of microcosm, nanoparticles and mesostructures, astrophysical and cosmological objects. Under the proposed kinetic approach, the uncertainty principle covers a wider spectrum of processes of approaching to equilibrium and object formation, than the absolute certainty principle. It refers, in particular, to nano-range-of-problems and mesoscopics as well as to cosmology. Both principles predict formation of objects that are not well-known or, at least, well-described so far. Among these are neutron-rich super-heavy and giant nuclei, biologic and organic-silicon mesoobjects, cosmological objects with the sizes considerably exceeding the size of a light sphere. 展开更多
关键词 objects Formation KINETICS PRINCIPLES UNCERTAINTY ABSOLUTE CERTAINTY Microcosm Nanoparticles and Mesostructures astrophysical and cosmological objects
下载PDF
Another Collimation Mechanism of Astrophysical Jet
4
作者 Yoshinari Minami 《Journal of Earth Science and Engineering》 2017年第2期74-89,共16页
The acceleration mechanism of astrophysical jet and the collimation mechanism narrowing down to a long distance have been examined so far. It is a collimation problem of how to narrow the astrophysical jet narrowly. F... The acceleration mechanism of astrophysical jet and the collimation mechanism narrowing down to a long distance have been examined so far. It is a collimation problem of how to narrow the astrophysical jet narrowly. Further, the model of the astrophysical jet acceleration mechanism is required to solve this collimation problem at the same time as well as its acceleration. At the present time, the magnetic force model (magnetic centrifugal force and magnetic pressure) is regarded as the most dominant theory which solves the two problems of astrophysical jet acceleration and collimation at the same time. In addition to the present astrophysical jet narrow collimation mechanism by magnetic tension (pinch) force, in this article, another collimation mechanism which narrows down an astrophysical jet is newly introduced. That is, since a curvature is generated in the space around the astrophysical jet by magnetic field, a kind of pressure equivalent to the gravitational effect is generated in the direction of the interior of astrophysical jet as well as the pinch force from the outer circumferential surface of the astrophysical jet. 展开更多
关键词 astrophysical jet accretion disk black hole collimation mechanism acceleration mechanism magnetic field continuum curvature space-time cosmology.
下载PDF
A Cosmological Model for the Early Universe: The Formation of Fundamental Particles
5
作者 Tharwat Mahmoud El-Sherbini 《Journal of High Energy Physics, Gravitation and Cosmology》 CAS 2022年第4期1073-1083,共11页
A cosmological model for the very early universe is proposed which may modify the present point of view of physicists and astrophysicists, concerning the very early universe at a miniscule fraction of a second, approx... A cosmological model for the very early universe is proposed which may modify the present point of view of physicists and astrophysicists, concerning the very early universe at a miniscule fraction of a second, approximately 10<sup>-60</sup> seconds after the Big Bang. The model proposes the presence of a primordial s-particle that, following the Big Bang, was violently ejected in all spatial directions together with extremely high-frequency radiation that dominates this era. The proposed s-particles underwent two geometrical phase transitions in space-time that led to the formation of the known fundamental particles (i.e., dark matter, quarks, electrons, neutrinos, etc.). Furthermore, in the model, the four fundamental forces may be accommodated within one structural framework. It shows that the electronic charge is not a fundamental quantity (intrinsic property of the particle), but rather that it can be derived from the tangential velocity of the s-particle. Moreover, it appears that the masses of the fundamental particles are proportional to the curvature of the path of the s-particle. 展开更多
关键词 cosmologY Nongalactic astrophysics Particle Physics High Energy Physics Atomic Physics
下载PDF
A Model for a Dual Universe
6
作者 Tharwat Mahmoud El-Sherbini 《Journal of High Energy Physics, Gravitation and Cosmology》 CAS 2024年第1期52-66,共15页
A model for a dual universe is proposed, based on the assumption that simultaneously with our universe an anti-matter counterpart was initiated immediately following the Big Bang. At the heart of the model is a primor... A model for a dual universe is proposed, based on the assumption that simultaneously with our universe an anti-matter counterpart was initiated immediately following the Big Bang. At the heart of the model is a primordial anti-particle that differentiates itself from its counterpart, a previously hypothesized S-particle responsible for the formation of our own universe, through its course of rotation. The angular rotation of the anti-particle, in accordance with space-time rotation, together with the counter rotation of the S-particle, resulted in a time difference in the formation processes of both universes and consequently led to a large distance between the spatial locations occupied by our universe and its dual counterpart in the same space-time continuum. The existence of this anti-matter universe might solve the present mystery of matter anti-matter asymmetry and thus explain why hardly any free anti-matter can be observed in our universe. Moreover, the model implicates the possibility of the presence of a repulsive gravitational force exerted by the clusters of anti-particles in the anti-matter universe upon our universe. The repulsive gravitational force from the clusters of antiparticles in the dual universe as a whole upon our universe is completely different from the electrostatic repulsive force between similarly charged particles. It is also different from that due to possible gravitational or anti-gravitational interaction between individual matter and antimatter or particle and its antiparticle that might violate the CPT invariance, the theory of general relativity or the law of energy conservation. It is rather, a kind of negative gravity that affects our universe as a whole, due to the opposite course of rotation of the dual anti-universe relative to ours. The effect of this opposite rotation of the dual universe can cause anti-gravitational waves that penetrate our universe interacting with the space-time mesh around the galaxies in our universe as a whole, resulting in a negative-like curvature in the shape of the space around them. This negative curvature pushes the galaxies outward, away from each other, leading to the accelerated expansion of our universe. The continuous anti-gravitational waves that permeate and fill our universe might cause a constant background ripples (space fluctuations) in the space of our solar system that can be experimentally observed. The repulsive force exerted by our dual universe could together with the expansion of space-time, influence our universe and might yield more insight on the origin of dark energy. . 展开更多
关键词 cosmologY ANTIMATTER High Energy astrophysics Particle Physics
下载PDF
等离子天体物理学与现代等离子体宇宙观 被引量:1
7
作者 吴德金 陈玲 《天文学报》 CAS CSCD 北大核心 2023年第3期4-27,共24页
现代科学表明宇宙中99%以上的可观测物质都处于等离子体状态,从小尺度的微观粒子动力学集体过程与能量转换机制到大尺度的宇宙等离子天体结构状态与爆发活动现象,都是等离子天体物理学的研究课题.从宇宙演化历史、大尺度结构形成以及爆... 现代科学表明宇宙中99%以上的可观测物质都处于等离子体状态,从小尺度的微观粒子动力学集体过程与能量转换机制到大尺度的宇宙等离子天体结构状态与爆发活动现象,都是等离子天体物理学的研究课题.从宇宙演化历史、大尺度结构形成以及爆发活动现象等方面,系统地论述了等离子天体物理学在现代天文学发展以及现代等离子体宇宙观形成中的重要作用.同时,结合空间卫星科学探测研究及其对现代天文学的巨大影响,进一步阐述了地球磁层和日球层等空间等离子体实地探测研究在等离子天体物理学研究中所扮演的“天然实验室”的独特作用. 展开更多
关键词 大爆炸宇宙论 宇宙大尺度结构 高能天体物理学:天体爆发活动 等离子天体物理学 宇宙论:等离子体宇宙观
下载PDF
How Dark Energy Might Be Produced by Black Holes
8
作者 Eugene Terry Tatum 《Journal of Modern Physics》 CAS 2023年第5期573-582,共10页
If confirmed, the new galactic observations in support of rapidly growing supermassive black holes in association with their production of dark energy may provide for a quantum leap forward in our understanding of bla... If confirmed, the new galactic observations in support of rapidly growing supermassive black holes in association with their production of dark energy may provide for a quantum leap forward in our understanding of black holes, dark energy, and universal expansion. The primary implication of these observations is that growth of black holes may well be coupled with universal expansion (“cosmological coupling”). Study of the Flat Space Cosmology (FSC) model, in conjunction with these new observations, suggests a novel mechanism of “black hole dark energy radiation”. This brief note gives a rationale for how the high gravitational energy density vacuum within or adjacent to a black hole horizon could be sufficiently energetic to pull entangled pairs of positive matter energy particles and negative dark energy “particles” of equal magnitude out of the horizon vacuum and send them off in opposite directions (i.e., gravitationally-attractive matter inward and gravitationally-repelling dark energy outward). One effect would be that a black hole can rapidly grow in mass-energy without mergers or the usual accretion of pre-existing matter. A second effect would be continual production of dark energy within the cosmic vacuum, fueling a continuous and finely-tuned light-speed expansion of the universe. 展开更多
关键词 astrophysics: Galaxies Black Holes Dark Energy Vacuum Energy cosmological Coupling Flat Space cosmology ER = EPR Gravitized Vacuum Dark Matter Hawking Radiation
下载PDF
观测宇宙学的一些新进展 被引量:2
9
作者 陈阳 何香涛 +1 位作者 李丹丹 王竞 《北京师范大学学报(自然科学版)》 CAS CSCD 北大核心 2005年第3期264-267,共4页
系统介绍了观测宇宙学和其最新进展,包括观测手段和哈勃常数和宇宙的年龄、宇宙的暗物质、暗能量、背景辐射、大尺度结构、元素丰度、活动星系核、中微子、γ暴等热点问题,并提出了观测宇宙学存在的问题和挑战.
关键词 天体物理学 观测宇宙学 新进展
下载PDF
伽玛射线暴与爱因斯坦相对论 被引量:3
10
作者 吴雪峰 陆埮 《物理学进展》 CSCD 北大核心 2006年第1期1-21,共21页
伽玛射线暴(简称伽玛暴)是当今天体物理领域最热门的研究领域之一。继过去几年内长时标伽玛暴(持续时标长于2秒)研究取得的不断突破,2005年以来短时标伽玛暴(短于2秒)之谜也开始被解开,短暴的双中子星并合模型第一次得到观测支持。最近... 伽玛射线暴(简称伽玛暴)是当今天体物理领域最热门的研究领域之一。继过去几年内长时标伽玛暴(持续时标长于2秒)研究取得的不断突破,2005年以来短时标伽玛暴(短于2秒)之谜也开始被解开,短暴的双中子星并合模型第一次得到观测支持。最近还发现一个红移高达6.3的伽玛暴,这标志着伽玛暴开始成为研究高红移宇宙学的探针。本文旨在对伽玛暴研究的历史和现状作一个回顾和评述,并就爱因斯坦所创立的相对论和宇宙学具体在伽玛暴研究中的应用作一些讨论。 展开更多
关键词 天体物理学 伽玛射线暴 综述 相对论 宇宙学
下载PDF
比较文化阐释学方法论 被引量:2
11
作者 安乐哲 赵延风(译) 温海明(译审) 《孔学堂》 CSSCI 2022年第3期4-13,I0004-I0014,共21页
本文从杜威关于直接经验的预设出发,阐述我的比较文化阐释学方法论。在比较文化阐释学领域,随着对一个尚未理解的传统中所包含的不同寻常的文化预设探究的深入,我们对自身哲学预设理解的自觉性也日益增强。这种通过其自身术语来理解某... 本文从杜威关于直接经验的预设出发,阐述我的比较文化阐释学方法论。在比较文化阐释学领域,随着对一个尚未理解的传统中所包含的不同寻常的文化预设探究的深入,我们对自身哲学预设理解的自觉性也日益增强。这种通过其自身术语来理解某一传统之类比的方法,要求我们对于客观性必须抛弃自己所熟悉的实有论之理解,而以一种共同的阐释性目标代之。为了这个我们可以信任的共同目标,我们放弃了存在绝对真理的客观性预设。 展开更多
关键词 阐释学 伽达默尔式“成见” 客观性 直接经验主义 过程宇宙论
下载PDF
论考古学学科目标和文化遗产的核心价值 被引量:7
12
作者 段清波 《中原文化研究》 2016年第3期87-94,共8页
承载文化与文明发生发展过程中核心基因的物质文化遗产,是不同时期宇宙观、社会治理体系及核心价值观三者相互作用的产物,是不同时期统领社会进程的核心价值观影响下的产物,它体现的是全社会成员在核心价值观指导下所形成的物质形态及... 承载文化与文明发生发展过程中核心基因的物质文化遗产,是不同时期宇宙观、社会治理体系及核心价值观三者相互作用的产物,是不同时期统领社会进程的核心价值观影响下的产物,它体现的是全社会成员在核心价值观指导下所形成的物质形态及其展现出来的观念体系。文化遗产不仅具有与生俱来的历史、艺术和科学等价值,还蕴含超越这三大价值之上的核心价值即文化价值。物质文化遗产的文化价值迄今并未得到深入的发掘和系统的诠释,与中国考古学学科目标及人才培养体系仅探求文化遗产的三大价值理念有关。突破传统价值认知框架的局限,创新考古学学科定位,形成长时段观察文化和文明的研究理念,探索发现和阐释文化遗产文化价值的研究路径和研究方法,弘扬中国文化和文明发展演变过程中优秀文化的当代价值,方可在全社会形成文化遗产就像生命中的空气、阳光和水一样须臾不可或缺的共识,让文化遗产的文化价值活起来,有助于形成未来中国社会发展的文化软实力。 展开更多
关键词 考古学学科目标 核心价值 宇宙观 社会治理体系
下载PDF
天体物理学的世纪回顾与展望
13
作者 何香涛 李庆康 《北京师范大学学报(自然科学版)》 CAS CSCD 北大核心 2000年第4期427-434,共8页
系统介绍 2 0世纪天文学研究取得的伟大成就 ,包括爱因斯坦的相对论 ,以及哈勃定律、大爆炸宇宙学模型等 .回顾了 2 0世纪天体物理学的“四大发现”以及“四大疑难问题”,并对 2
关键词 天体物理学 相对论 宇宙模型 哈勃定律
下载PDF
无我之境的抒情内涵
14
作者 徐炼 《南京师范大学文学院学报》 CSSCI 2014年第1期64-71,共8页
"无我之境"和"有我之境"的区别不仅仅是抒情形式的差异。"无我之境"的观照方式"以物观物"源于庄子"丧我"、"物化"思想,所表现的是本真的宇宙生命情怀。"无我之境&qu... "无我之境"和"有我之境"的区别不仅仅是抒情形式的差异。"无我之境"的观照方式"以物观物"源于庄子"丧我"、"物化"思想,所表现的是本真的宇宙生命情怀。"无我之境"和儒家、道家性情论有关。 展开更多
关键词 无我之境 以物观物 宇宙生命情怀
下载PDF
天文望远镜的历史与展望——兼论清华宽视场巡天望远镜(MUST) 被引量:5
15
作者 蔡峥 张超 樊凡 《实验技术与管理》 CAS 北大核心 2021年第5期1-9,37,共10页
最近10年,天文学、天体物理学5获诺贝尔物理学奖,整个领域呈加速发展态势。目前,天文学已进入多信使、海量数据、大科学工程的时代,人类对宇宙的观测和理解在深度、广度和时域维度上都将实现跨越式发展,有望发现宇宙的全新规律。该文回... 最近10年,天文学、天体物理学5获诺贝尔物理学奖,整个领域呈加速发展态势。目前,天文学已进入多信使、海量数据、大科学工程的时代,人类对宇宙的观测和理解在深度、广度和时域维度上都将实现跨越式发展,有望发现宇宙的全新规律。该文回顾了数百年望远镜的发展史,介绍了清华大学即将建设的宽视场光谱巡天望远镜(multiplexed survey telescope,MUST)。MUST建成后,其光谱巡天能力将比现有水平提高10倍以上。配合未来的全波段巡天设备,MUST有望在暗能量演化、星系宇宙学、引力波宇宙学等方向取得突破,使我国在地基天文观测和相关技术领域达到国际一流或领先水平。此外,MUST将带动先进光学、精密机械、高性能探测器等领域的巨大进步。 展开更多
关键词 天文望远镜 宇宙学 天体物理
下载PDF
Thirty Meter Telescope Detailed Science Case:2015 Warren Skidmore on behalf of the TMT International Science Development Teams &TMT Science Advisory Committee 被引量:4
16
作者 Thirty Meter Telescope International Observatory 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2015年第12期1945-2140,共196页
The TMT Detailed Science Case describes the transformational science that the Thirty Meter Telescope will enable. Planned to begin science operations in 2024, TMT will open up opportunities for revolutionary discoveri... The TMT Detailed Science Case describes the transformational science that the Thirty Meter Telescope will enable. Planned to begin science operations in 2024, TMT will open up opportunities for revolutionary discoveries in essen- tially every field of astronomy, astrophysics and cosmology, seeing much fainter objects much more clearly than existing telescopes. Per this capability, TMT's sci- ence agenda fills all of space and time, from nearby comets and asteroids, to exo- planets, to the most distant galaxies, and all the way back to the very first sources of light in the universe. More than 150 astronomers from within the TMT partner- ship and beyond offered input in compiling the new 2015 Detailed Science Case. The contributing astronomers represent the entire TMT partnership, including the California Institute of Technology (Caltech), the Indian Institute of Astrophysics (HA), the National Astronomical Observatories of the Chinese Academy of Sciences (NAOC), the National Astronomical Observatory of Japan (NAOJ), the University of California, the Association of Canadian Universities for Research in Astronomy (ACURA) and US associate partner, the Association of Universities for Research in Astronomy (AURA). 展开更多
关键词 instrumentation and method -- cosmology and nongalactic astrophysics-- Earth and planetary astrophysics -- astrophysics of galaxies -- high energy astro-physical phenomena
下载PDF
实验室研究HH天体喷流进展介绍
17
作者 刘畅 贺汀兰 仲佳勇 《北京师范大学学报(自然科学版)》 CAS CSCD 北大核心 2017年第4期399-405,共7页
实验室天体物理是一门利用实验室环境来模拟、研究天体物理现象的新兴学科.天体物理中的喷流现象,尤其是Herbig-Haro天体,一直是实验室天体物理的研究热点.通过不同的实验方法,如激波挤压、Z箍缩装置和激光驱动等方式制造喷流,研究者对... 实验室天体物理是一门利用实验室环境来模拟、研究天体物理现象的新兴学科.天体物理中的喷流现象,尤其是Herbig-Haro天体,一直是实验室天体物理的研究热点.通过不同的实验方法,如激波挤压、Z箍缩装置和激光驱动等方式制造喷流,研究者对于实验室天体物理中的喷流现象的认识在不断深入.本文对这些研究进行简要介绍,并对未来的研究进行一些展望. 展开更多
关键词 实验室天体物理 强激光 等离子体 喷流 Herbig—Haro天体
下载PDF
WMAP第3年的宇宙学参数对星系团中巨弧数目的影响
18
作者 李国亮 《天文学进展》 CSCD 北大核心 2007年第3期262-269,共8页
该文利用高精度的大尺度N体数值模拟,研究了WMAP(Wilkinson Microwave Anisotropy Probe)第3年的观测结果对星系团中的巨弧数目的影响,发现预言的巨弧数目比主流的ACDM模型预言的要低80%多。加入绝热气体几乎不会改变巨弧的发生概率,而... 该文利用高精度的大尺度N体数值模拟,研究了WMAP(Wilkinson Microwave Anisotropy Probe)第3年的观测结果对星系团中的巨弧数目的影响,发现预言的巨弧数目比主流的ACDM模型预言的要低80%多。加入绝热气体几乎不会改变巨弧的发生概率,而引入恒星形成和超新星反馈后得到的概率不会大于原来的1.3倍。如此小的贡献是因为虽然有恒星的数值模拟得到的星系团具有更高的中心密度,但同时星系团的形状更趋球对称,这是影响巨弧概率的2个相反的因素。以前基于ACDM模型预言的巨弧概率还不能很好地与观测相符,WMAP第3年的观测结果将更难以解释。 展开更多
关键词 天体物理学 宇宙学 星系团 引力透镜
下载PDF
On Boundaries of Cosmos
19
作者 Emil Edipovich Lin 《World Journal of Mechanics》 2015年第1期1-6,共6页
This paper establishes asymptotic time dependences of characteristic sizes of astrophysical and cosmological objects. These dependences are obtained on the basis of uncertainty principle applied in cosmic scales in ap... This paper establishes asymptotic time dependences of characteristic sizes of astrophysical and cosmological objects. These dependences are obtained on the basis of uncertainty principle applied in cosmic scales in approximation of spherical symmetry in Euclidean geometry. The proposed analytical approach makes it possible to determine spatial boundaries of the uniformity of matter distribution in the Universe, and a size of cosmic sphere which contains numerous groups of interacting universes. 展开更多
关键词 Uncertainty PRINCIPLE COSMOS astrophysical/cosmological objects CHARACTERISTIC SIZES Time
下载PDF
Neutron Star Motion in the Disk Galaxy
20
作者 魏迎春 A. Taani 潘元月 王静 蔡炎 刘高潮 罗阿里 张洪波 赵永恒 《Chinese Physics Letters》 SCIE CAS CSCD 2010年第11期212-215,共4页
The neutron star motions are based on the undisturbed finitely thick galactic disk gravitational potential model. Two initial conditions, i.e. the locations and velocities, are considered. The Monte Carlo method is em... The neutron star motions are based on the undisturbed finitely thick galactic disk gravitational potential model. Two initial conditions, i.e. the locations and velocities, are considered. The Monte Carlo method is employed to separate rich diversities of the orbits of neutron stars into several sorts. The Poineare section has the potential to play an important role in the diagnosis of the neutron star motion. It has been observed that the increasing ratio of the motion range vertical to the galactic plane to that parallel to the galactic plane results in the irregularity of neutron star motion. 展开更多
关键词 Gravitation and cosmology astrophysics and astroparticles
下载PDF
上一页 1 2 下一页 到第
使用帮助 返回顶部