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Calculation of the Mass of the Universe, the Radius of the Universe, the Age of the Universe and the Quantum of Speed 被引量:3
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作者 Claude Mercier 《Journal of Modern Physics》 2019年第8期980-1001,共22页
The universe is vast and when we look at the sky, its parameters (dimensions, mass, and age) seems limitless. Lema&icirc;tre proposed that the universe began from a primeval-atom [1] which was later ironically nic... The universe is vast and when we look at the sky, its parameters (dimensions, mass, and age) seems limitless. Lema&icirc;tre proposed that the universe began from a primeval-atom [1] which was later ironically nicknamed by Hoyle “Big Bang” in a BBC broadcast in 1949 [2]. From general relativity, Einstein proposed a cosmological model [3] with a spatially finite universe. He assumed a uniform distribution of matter in a huge 4-D sphere. Even if his equations were showing that the universe was either contracting or expanding, Einstein introduced the “cosmological constant” in his equation to force the universe to be static (being consistent with the general way of thinking of his time). In 1929, from observations of galaxies, Hubble found that the universe was expanding. From that moment, Einstein discarded his cosmological constant as an unnecessary fudge factor. Many cosmological models have been built over time. Each of them excels in explaining some aspects of the universe. We consider that the global topology of the universe is not known, but making the assumptions that it is relatively homogenous and isotropic, its extrapolated local topology leads us to some global “apparent” parameters. From our new cosmological model, we calculate the main parameters of the universe which are its apparent mass mu, its apparent curving radius Ru, its apparent age Tu and the “quantum of speed” &epsilon;v. The quantum of speed is a new notion in physics. It is the smallest speed increment that may exist. For metrology purposes, we calculate these parameters from the most precise physics’ parameters available. 展开更多
关键词 MASS of the universe HUBBLE RADIUS age of the universe QUANTUM of SPEED Dirac Large Numbers Hypothesis
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Introducing a 2nd Universal Space-Time Constant Can Explain the Observed Age of the Universe and Dark Energy
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作者 Herman A. van Hoeve 《World Journal of Mechanics》 2024年第2期9-22,共14页
The purpose of this paper is to introduce new theoretical concepts as opposed to accepting the existence of dark entities, such as dark energy. This research sought to introduce a 2<sup>nd</sup> universal ... The purpose of this paper is to introduce new theoretical concepts as opposed to accepting the existence of dark entities, such as dark energy. This research sought to introduce a 2<sup>nd</sup> universal space-time constant, besides having a finite speed constant (speed of light in vacuum c). A finite universal age constant b is introduced. Namely, this paper shows that the changes in the Earth’s anomalistic year duration over time support the hypothesis of the age of the universe correlating with a maximum number of orbital revolutions constant. Neglecting the gravitational influence of other cosmological entities in the proximity of the Earth, the constant maximum number of revolutions is herewith determined solely by the Earth’s orbital revolutions around the Sun. The value of the universal age constant b is calculated to be around 13.8 billion orbital revolutions, derived out of an equation related to the changes in the Earth’s anomalistic year duration over time and the so-called Hubble tension. The above-mentioned calculated value b correlates well with the best fit to measured data of the cosmic microwave background radiation (CMBR) by the Planck spacecraft, the age of the observed universe is measured to be approximately 13.787 ± 0.020 billion years (2018 final data release). Developing a theory with this 2<sup>nd</sup> universal space-time constant b, being covariant with respect to the Lorentz transformations when time spans are large, gives results such as: A confirmation of the measured CMBR value of 13.787 ± 0.020 billion years. Correlating well with the observed expansion rate of the universe (dark energy). The universe’s expansion accelerating over the last four to five billion years. 展开更多
关键词 Anomalistic Year Orbital Revolution Hubble Tension age of the universe Cosmological Constant Dark Energy Cosmic Microwave Background
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Mass of the Universe from Quarks: A Plausible Solution to the Cosmological Constant Problem
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作者 Kevin Oramah 《Journal of Modern Physics》 2023年第12期1672-1692,共21页
A framework to estimate the mass of the universe from quarks is presented, taking spacetime into account. This is a link currently missing in our understanding of physics/science. The focus on mass-energy balance is a... A framework to estimate the mass of the universe from quarks is presented, taking spacetime into account. This is a link currently missing in our understanding of physics/science. The focus on mass-energy balance is aimed at finding a solution to the Cosmological Constant (CC) problem by attempting to quantize space-time and linking the vacuum energy density at the beginning of the universe and the current energy density. The CC problem is the famous disagreement of approximately 120 orders of magnitude between the theoretical energy density at the Planck scale and the indirectly measured cosmological energy density. Same framework is also used to determine the mass of the proton and neutron from first principles. The only input is the up quark (u-quark) mass, or precisely, the 1st generation quarks. The method assumes that the u-quark is twice as massive as the down-quark (d-quark). The gap equation is the starting point, introduced in its simplest form. The main idea is to assume that all the particles and fields in the unit universe are divided into quarks and everything else. Everything else means all fields and forces present in the universe. It is assumed that everything else can be “quark-quantized”;that is, assume that they can be quantized into similar sizeable u-quarks and/or it’s associated interactions and relations. The result is surprisingly almost as measured and known values. The proton structure and mass composition are also analysed, showing that it likely has more than 3 quarks and more than 3 valence quarks. It is also possible to estimate the percentage of dark matter, dark energy, ordinary matter, and anti-matter. Finally, the cosmological constant problem or puzzle is resolved by connecting the vacuum energy density of Quantum Field Theory (5.1E+96 kg/m<sup>3</sup>) and the energy density of General Relativity (1.04E−26 kg/m<sup>3</sup>). Upon maturation, this framework can serve as a bridging platform between Quantum Field Theory and General Relativity. Other aspects of natures’ 展开更多
关键词 Cosmological Constant Proton Mass-Structure Quark-Quantization Dark Matter Dark Energy age of the universe Energy Density Spacetime Quantization
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A New Physics Would Explain What Looks Like an Irreconcilable Tension between the Values of Hubble Constants and Allows <i>H<sub>0</sub></i>to Be Calculated Theoretically Several Ways
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作者 Claude Mercier 《Journal of Modern Physics》 2021年第12期1656-1707,共52页
<p> Observing galaxies receding from each other, Hubble found the universe’s expansion in 1929. His law that gives the receding speed as a function of distance implies a factor called Hubble constant <em>... <p> Observing galaxies receding from each other, Hubble found the universe’s expansion in 1929. His law that gives the receding speed as a function of distance implies a factor called Hubble constant <em>H</em><sub><em>0</em></sub>. We want to validate our theoretical value of <em style="white-space:normal;">H</em><sub style="white-space:normal;"><em>0</em></sub> ≈ 72.09548580(32) km<span style="white-space:nowrap;"><span style="white-space:nowrap;"><span style="white-space:nowrap;"><span style="white-space:nowrap;"><span style="white-space:nowrap;">&sdot;</span></span></span></span></span>s<span style="white-space:nowrap;"><span style="white-space:nowrap;"><sup><span style="white-space:nowrap;"><span style="white-space:nowrap;">-</span></span></sup></span></span><sup>1</sup><span style="white-space:nowrap;"><span style="white-space:nowrap;"><span style="white-space:nowrap;"><span style="white-space:nowrap;"><span style="white-space:nowrap;">&sdot;</span></span></span></span></span>MParsec<sup><span style="white-space:nowrap;"><span style="white-space:nowrap;"><span style="white-space:nowrap;"><span style="white-space:nowrap;">-</span></span></span></span>1</sup> with a new cosmological model found in 2019. This model predicts what may look like two possible values of <em style="white-space:normal;">H</em><sub style="white-space:normal;"><em>0</em></sub>. According to this model, the correct equation of the apparent age of the universe gives ~ 14.14 billion years. In approximation, we get the well-known equation 1/<em style="white-space:normal;">H</em><sub style="white-space:normal;"><em>0</em></sub> ≈ 13.56 billion years. When we force these ages to fit the 1/<em style="white-space:normal;">H</em><sub style="white-space:normal;"><em>0</em></sub> formula, it gives two different Hubble constant values of ~69.2 and 72.1 km<span style="white-space:nowrap;"><span style="white-space:nowrap;"><span style="white-space:nowrap;"><span style="white-space:nowrap;"><span style="white-space:nowrap;"><span style="white-s 展开更多
关键词 Hubble Constant H0 Hubble Tension age of the universe
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宇宙年龄研究的最新进展 被引量:1
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作者 李志宏 《原子能科学技术》 EI CAS CSCD 北大核心 2019年第10期1747-1754,共8页
宇宙年龄是宇宙模型的基本参量,对其精确测定有助于人们理解宇宙的起源、结构和演化过程,也能帮助认识暗物质和暗能量的本质。本文回顾天体物理应用普遍的3种测定宇宙年龄的方法,并叙述了部分最新研究进展。随着科技的进步,人们对宇宙... 宇宙年龄是宇宙模型的基本参量,对其精确测定有助于人们理解宇宙的起源、结构和演化过程,也能帮助认识暗物质和暗能量的本质。本文回顾天体物理应用普遍的3种测定宇宙年龄的方法,并叙述了部分最新研究进展。随着科技的进步,人们对宇宙年龄的认识逐渐趋于统一,即宇宙诞生于距今138亿年的宇宙大爆炸。一些重要的核天体物理数据对宇宙年龄起关键的约束作用,需进行细致研究以减少测量误差。宇宙常数精细测量结果还存在5%的差异,对此深入理解或许会孕育宇宙学领域重大突破。 展开更多
关键词 宇宙年龄 大爆炸 恒星演化 放射性纪年
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黏滞性流体与宇宙年龄问题
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作者 冯朝君 李新洲 《中国科学:物理学、力学、天文学》 CSCD 北大核心 2011年第12期1378-1384,共7页
在宇宙的演化过程当中,经历了暴胀、辐射以及物质为主时期.如果宇宙现在仍处于物质为主时期,那么理论上所得到的宇宙年龄大概是在80~100亿年左右.另一方面,人们测得一些古老星团的年龄超过了110亿年,由此可见,理论预言与观测结果不相符... 在宇宙的演化过程当中,经历了暴胀、辐射以及物质为主时期.如果宇宙现在仍处于物质为主时期,那么理论上所得到的宇宙年龄大概是在80~100亿年左右.另一方面,人们测得一些古老星团的年龄超过了110亿年,由此可见,理论预言与观测结果不相符合,这就是宇宙的年龄问题.当前的观测表明宇宙正处于加速膨胀时期,人们通常将加速的原因归结于宇宙中存在着一种被称为暗能量的物质组分.人们进一步发现由于这种组分可以使理论上预言的宇宙年龄变大,从而缓解了宇宙年龄问题.可是,最新的观测表明,仍有一些天体的年龄比预言的宇宙年龄要大,比如说类星体APM08279+5255,它在红移等于3.91时的年龄大概是21亿年,超过了当时的宇宙年龄.事实上,通常人们在研究宇宙学中,仅仅考虑了理想流体这一简单模型,而该模型可能过于简单.因此,本文将考虑带有黏滞性的流体.通过引入黏滞性,宇宙的年龄问题被进一步缓解了.尽管,本文考虑一类被称为Ricci暗能量的模型,但是所得到的结论可以推广和应用到各种暗能量模型中. 展开更多
关键词 黏滞性 宇宙学年龄 暗能量
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宇宙中物质的压力对宇宙年龄的影响
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作者 张同杰 郭守元 《北京师范大学学报(自然科学版)》 CAS CSCD 北大核心 2000年第5期657-658,共2页
While the pressureless dust assumption has been widely adopted in the standard model of cosmology, a quantitative estimate of the actual contributions of the baryonic matter and the hot/cold dark matter to the age of ... While the pressureless dust assumption has been widely adopted in the standard model of cosmology, a quantitative estimate of the actual contributions of the baryonic matter and the hot/cold dark matter to the age of the Universe has not yet been made in literature. They provide a simple scenario of how the solution, e.g. the age of the Universe, is affected by the inclusion of the thermal pressure of the baryon and dark matter particles. 展开更多
关键词 暗物质 热压力 宇宙年龄 宇宙学
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宇宙常数与宇宙年龄问题 被引量:1
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作者 俞允强 马駬 陈时 《天体物理学报》 CSCD 1997年第1期1-7,共7页
本文用球对称扰动模型导出了星系暗晕的平均密度与形成时间的关系 ,并由此估算银河系的形成时间tV.我们把球状星团的年龄作为银河系年龄tG 的代表 ,则tG+tV 是宇宙年龄 .对Ωλ=0 ,0 .7和 0 .8的平坦宇宙模型 ,本文计算并讨论了能与它... 本文用球对称扰动模型导出了星系暗晕的平均密度与形成时间的关系 ,并由此估算银河系的形成时间tV.我们把球状星团的年龄作为银河系年龄tG 的代表 ,则tG+tV 是宇宙年龄 .对Ωλ=0 ,0 .7和 0 .8的平坦宇宙模型 ,本文计算并讨论了能与它相洽的哈勃常数的范围 .结果表明 ,若哈勃常数大到 80km·s- 1 Mpc- 1 左右 。 展开更多
关键词 宇宙常数 宇宙年龄 星系形成
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Decisive Role of Gravitational Parameter G in Cosmology
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作者 Vladimir S. Netchitailo 《Journal of High Energy Physics, Gravitation and Cosmology》 2023年第3期611-625,共15页
In 1937, P. Dirac proposed the Large Number Hypothesis and the Hypothesis of the variable gravitational “constant”, and later added the notion of continuous creation of Matter in the World. The Hypersphere World-Uni... In 1937, P. Dirac proposed the Large Number Hypothesis and the Hypothesis of the variable gravitational “constant”, and later added the notion of continuous creation of Matter in the World. The Hypersphere World-Universe Model (WUM) follows these ideas, albeit introducing a different mechanism of Matter creation. In this paper, we show that Gravitational parameter G that can be measured directly makes measurable all Cosmological parameters, which cannot be measured directly. 展开更多
关键词 World-universe Model Fundamental Physical Constants Primary Cosmological Parameters Dirac Large Number Intergalactic Plasma Medium of the World age of universe Maxwell’s Equations
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A Possible Alternative to the Accelerating Universe III
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作者 Frank R. Tangherlini 《Journal of Modern Physics》 2016年第13期1829-1844,共16页
This work extends the author’s two previous works (2015), Journal of Modern Physics, 6, 78-87, and 1360-1370, by obtaining the index of refraction n of the dark energy for additional values of the cosmological densit... This work extends the author’s two previous works (2015), Journal of Modern Physics, 6, 78-87, and 1360-1370, by obtaining the index of refraction n of the dark energy for additional values of the cosmological density parameters, and for the two methods of obtaining n: least squares fit, and electromagnetic theory. Comparison of the alternative model with the accelerating universe for the new values of the density parameters and n is given in two tables. The new values for n are used to obtain a range of ages for the Einstein de Sitter (EdS) universe. It is shown that the EdS universe must be older than the comparison accelerating universe. This requirement is met for the Planck 2015 value of the Hubble constant, corrected for the speed of light reduction by n. A supporting measurement as well as a disagreeing measurement is also discussed. Possible support from a stellar age determination is also discussed. It is shown that the expression obtained earlier for the increased apparent magnitude of the SNe Ia provides as good a fit for a closed universe with Ω(tot = 1.005) , as it does for the flat EdS universe. Comparison is presented in a third table. An upper bound on Ω<sub>Λ</sub> is given for a closed universe that eventually collapses back on itself that is too small for the value needed for the accelerating universe. 展开更多
关键词 Dark Energy Speed of Light age of universe Closed universe
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A Possible Solution to the Disagreement about the Hubble Constant II
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作者 Frank R. Tangherlini 《Journal of Modern Physics》 2020年第8期1215-1235,共21页
This work continues the previous study (2018) Journal of Modern Physics. 9, 1827-1837, that proposes that the disagreement arises because the cosmic microwave background (CMB) value for the Hubble constant <em>H... This work continues the previous study (2018) Journal of Modern Physics. 9, 1827-1837, that proposes that the disagreement arises because the cosmic microwave background (CMB) value for the Hubble constant <em>H</em><sub><em>0</em></sub> is actually for a universe which is decelerating rather than accelerating. It is shown that when <em>H</em><sub><em>0</em></sub> of Freedman et al. (2019) Astrophysical Journal, 882: 34 (24 pp.) is re-determined for redshift <em>z </em>= 0.07, by replacing <em>q</em><sub><em>0 </em></sub>= <span style="white-space:nowrap;">&minus;</span>0.53 with <em style="white-space:normal;">q</em><sub style="white-space:normal;"><em>0 </em></sub><span style="white-space:normal;">= <span style="white-space:nowrap;">&minus;</span>0.5</span>, the new lower value is in excellent agreement (0.1%) with the CMB <em>H</em><sub><em>0</em></sub>. The model is modified to include the clustering of galaxies, and the recognition that there are clusters that do not experience the Hubble expansion, such as the Local Group, and hence, in accordance with the model, within the Local Group the speed of light is <em>c</em>. The bearing of this result on the neutrino and light time delay from SN1987a is discussed. It is suggested that the possible emission of a neutrino from the blazar TXS-0506+56, that was flaring at the time, as well as possible neutrino emission earlier, may arise instead from a more distant source that happens to be, angle-wise, near the blazar, and hence the correlation is accidental. The model is further modified to allow for a variable index of refraction, and a comparison with the ΛCDM model is given. The age of the universe for different values of<em> H</em><sub><em>0</em></sub> is studied, and comparison with the ages of the oldest stars in the Milky Way is discussed. Also, gravitational wave determination of <em>H</em><sub><em>0</em></sub> is briefly discussed. 展开更多
关键词 Hubble Constant Disagreement Decelerating universe Galactic Clusters age of universe
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宇宙微波背景辐射对超高能宇宙线流强的影响 被引量:2
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作者 覃克宇 覃绍先 《云南师范大学学报(自然科学版)》 2000年第6期32-34,共3页
文章指出 :(1 )在 E=5× 1 0 1 9e V附近 ,对所有 x(x是宇宙线飞行的距离 ) ,超高能宇宙线流强略有增强 ;(2 )在 1 .0× 1 0 2 0 e V≤ E≤ 5.0× 1 0 2 4e V能区内 ,宇宙微波背景辐射的作用仅使超高能宇宙线流强有所减弱 ,... 文章指出 :(1 )在 E=5× 1 0 1 9e V附近 ,对所有 x(x是宇宙线飞行的距离 ) ,超高能宇宙线流强略有增强 ;(2 )在 1 .0× 1 0 2 0 e V≤ E≤ 5.0× 1 0 2 4e V能区内 ,宇宙微波背景辐射的作用仅使超高能宇宙线流强有所减弱 ,在 x≤ 2 0 0 0 Mpc区域内 ,减弱系数 F(X,E)≡ j(x,E) /j(0 ,E)≥ 0 .34。 展开更多
关键词 超高能宇宙线 微波背景辐射 宇宙年龄
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Convergent Calculations That Dark Solutions Are Reflective of Mass-Energy yet to Occur
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作者 Michael A. Persinger 《International Journal of Astronomy and Astrophysics》 2012年第3期125-128,共4页
The discrepancy between the observed and expected estimates from universal constants of mass-energy within the universe is in the order of a factor of ~10. Discrepancies between numerical solutions between the models ... The discrepancy between the observed and expected estimates from universal constants of mass-energy within the universe is in the order of a factor of ~10. Discrepancies between numerical solutions between the models of Dirac, Szydowski-Godlowski, and Friedman could be accommodated by the gnomonic solution of 0.44 for a square that displays both linearity and curvature (flare). This value is also reflected in dimensionless parameter A, the term for 4D-G (gravitational constant) transformation, and the optimal k in Friedman’s universe. One interpretation from G? (density), as-suming an effective average mass of 1 proton/m3 as a universal, one-particle force, is that dark solutions reflect the matter yet to occur in the open cold matter model of ~90 billion years. 展开更多
关键词 DARK Matter Gravity Physical COSMOLOGY Square Gnomon age of universe
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恒星的年龄是怎样确定的
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作者 王家骥 《自然杂志》 北大核心 2012年第2期108-113,共6页
恒星年龄,是恒星物理学中一个十分重要的问题,这个问题是否能够得到很好的解决,涉及到天文学中很多其他的重要问题。小到为了确定外星行星的年龄,大到宇宙的年龄,都与恒星的年龄直接有关。本文将简要地介绍目前在天文学中究竟有哪些方... 恒星年龄,是恒星物理学中一个十分重要的问题,这个问题是否能够得到很好的解决,涉及到天文学中很多其他的重要问题。小到为了确定外星行星的年龄,大到宇宙的年龄,都与恒星的年龄直接有关。本文将简要地介绍目前在天文学中究竟有哪些方法可以用来推断和估计恒星的年龄,以及这些方法都还存在着哪些问题影响恒星年龄估值的准确性。 展开更多
关键词 恒星 恒星年龄 恒星演化 外星行星 宇宙年龄
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老年友好大学的主要做法及对我国高校开展老年教育的启示
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作者 江凤娟 万义文 余年年 《终身教育研究》 2024年第4期89-95,共7页
发展老年教育是积极应对人口老龄化国家战略的重要内容,高校开展老年教育对于丰富老年教育资源供给、缓解老年教育的主要矛盾具有重大意义。老年友好大学是美国老年学学会举办的旨在推动全球高校开展老年教育的国际联盟。研究基于资源... 发展老年教育是积极应对人口老龄化国家战略的重要内容,高校开展老年教育对于丰富老年教育资源供给、缓解老年教育的主要矛盾具有重大意义。老年友好大学是美国老年学学会举办的旨在推动全球高校开展老年教育的国际联盟。研究基于资源供给、人才培养、机制创新的框架对老年友好大学的做法进行系统性分析,提出增强高校服务老龄化社会的理念、开展终身学习项目等老年教育活动、以现代教育技术手段开发开放面向老年人的数字教育资源、加强老年教育学的学科建设和人才培养、创新管理与运行的机制、建设相关政策制度等对策建议,以促进我国高校开展老年教育。 展开更多
关键词 老年教育 高等教育 老年友好大学 老年大学
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Frequency Decay through Electromagnetic Radiation Absorption and Re-Emission by Inter-Galactic Dark Matter as an Alternate Explanation for the Hubble Constant
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作者 David Grant Taylor 《Journal of High Energy Physics, Gravitation and Cosmology》 2016年第3期301-311,共11页
There is an alternate cause for the decay rate defined by Edwin Hubble’s Cosmological Constant Theory. It can be proposed because inward motion is observed in the local Galaxies||Star groups around the Milky Way. The... There is an alternate cause for the decay rate defined by Edwin Hubble’s Cosmological Constant Theory. It can be proposed because inward motion is observed in the local Galaxies||Star groups around the Milky Way. The recession velocity of Galaxies farther out of is reasoned entirely from the increasing redshift in the frequency. The smaller the image of observed Galaxy/Cluster objects, the greater the downward shift in frequency of all Electro-Magnetic signals [EM]. An alternate cause for that downward shift could be through the absorption and re-emission through matter, leading to the absorption of some fraction of the energy quanta. There is nowhere in our Local Universe that is both absolutely devoid of matter and the continual formation of objects of all scales. If redshift was because of space expansion, it would increase the distance that signal had to travel. So a signal from GN-z11 stellar structure at 13.4 billion light years [LY] would take 13.4 billion years to travel. Assuming 13.8 billion years since the Big Bang would mean GN-z11 object travelled 13.4 billion LY in 400 million years. A current value for the Hubble constant is: H<sub>0</sub>=(67.8 ± 0.77) km s <sup>-1</sup> Mpc <sup>-1</sup>  a frequency is shift of 67.8/c over a single Mpc. An alternate expression would be a shift factor 2.261560E-5 over a distance of 3.08567E22 m or a redshift of 7.32923E-28 over a metre because of passage through a medium. Dark matter is a currently accepted phenomenon. It is proposed that properties include redshift’s all normal matters that are put upon EM||Boson signals at the fraction stated above. The signal reduction|| frequency distortion happens at a quantum level for each occurrence, and so is not detectable until passage through millions of LY of Dark Matter. Support for this alternate supposition is reasoned from the fact that the M31 Galaxy and the NGC 300 Galaxy are at distances inconsistent with their Hubble recession velocity. 展开更多
关键词 Big Bang Theory Dark Matter EM Frequency Decay GN-z11 Body Density ||Volume|| age universe Origin CMBR Comic Egg Infinite Milky Way [MW] Andromeda Galaxy [M31]
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宇宙核时钟不确定度的研究 被引量:1
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作者 张蔚泓 牛中明 +2 位作者 王枫 龚孝波 孙保华 《物理学报》 SCIE EI CAS CSCD 北大核心 2012年第11期201-207,共7页
基于经典快过程理论模型,研究了原子核物理输入量的不确定性对Th/U,Th/Hf,Th/Eu,Th/Os,Th/Ir等核时钟估算宇宙年龄的影响.其中利用蒙特卡罗模拟方法,计算了不同质量模型下由单中子分离能引起的不确定性.结果表明,Th/U核时钟由原子核质... 基于经典快过程理论模型,研究了原子核物理输入量的不确定性对Th/U,Th/Hf,Th/Eu,Th/Os,Th/Ir等核时钟估算宇宙年龄的影响.其中利用蒙特卡罗模拟方法,计算了不同质量模型下由单中子分离能引起的不确定性.结果表明,Th/U核时钟由原子核质量不确定性引起的误差大约为1.66 Ga,比其他核时钟小2 Ga以上.对Th/Eu,Th/Os和Th/Ir核时钟,该误差分别为5.15,3.93和3.95 Ga.由于Th/Hf核时钟受质量模型影响太大,而Th/Os和Th/Ir的计算结果又明显偏大,因此在年龄计算中都需谨慎使用.综合考虑原子核物理输入量和天文观测带来的误差,利用Th/U核时钟估算的宇宙年龄为14.1±3.8 Ga. 展开更多
关键词 宇宙年龄 核时钟 快中子俘获过程 原子核质量
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数字时代地方院校复合型出版人才培养模式研究 被引量:7
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作者 宋艳丽 《出版科学》 CSSCI 北大核心 2012年第6期62-65,共4页
通过对现阶段地方院校编辑出版学本科教育存在的问题进行梳理,探索如何从自身学科背景和现有教育资源出发,发挥优势,突出特色,培养为地方经济文化发展服务的复合型出版人才,同时对数字时代复合型出版人才的培养模式提出建议,以供同类院... 通过对现阶段地方院校编辑出版学本科教育存在的问题进行梳理,探索如何从自身学科背景和现有教育资源出发,发挥优势,突出特色,培养为地方经济文化发展服务的复合型出版人才,同时对数字时代复合型出版人才的培养模式提出建议,以供同类院校参考。 展开更多
关键词 数字出版时代 地方院校 编辑出版学专业 人才培养模式
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