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Fe-S共掺杂锐钛矿相TiO_2的第一性原理研究 被引量:11
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作者 吴国浩 郑树凯 刘磊 《中国有色金属学报》 EI CAS CSCD 北大核心 2013年第3期852-858,共7页
利用基于密度泛函理论的第一性原理平面波超软赝势方法对未掺杂、Fe和S单掺杂及Fe-S共掺杂锐钛矿相TiO2的电子结构进行计算,分析Fe、S单掺杂及Fe-S共掺杂对锐钛矿相TiO2的晶体结构、能带、态密度和光吸收性质的影响。结果表明,掺杂后TiO... 利用基于密度泛函理论的第一性原理平面波超软赝势方法对未掺杂、Fe和S单掺杂及Fe-S共掺杂锐钛矿相TiO2的电子结构进行计算,分析Fe、S单掺杂及Fe-S共掺杂对锐钛矿相TiO2的晶体结构、能带、态密度和光吸收性质的影响。结果表明,掺杂后TiO2的晶格发生畸变,原子间键长的变化使晶格发生膨胀;掺杂后TiO2的禁带宽度减小,并在禁带中引入杂质能级,导致TiO2的吸收带边红移;与Fe和S单掺杂相比,Fe-S共掺杂锐钛矿相TiO2的吸收带边红移程度更大。 展开更多
关键词 TIO2 Fe-s共掺杂 密度泛函理论 晶体结构 红移
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S高掺杂对锐钛矿TiO_2电子结构和红移影响的第一性原理研究 被引量:2
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作者 侯清玉 《内蒙古工业大学学报(自然科学版)》 2011年第3期197-203,共7页
基于密度泛函理论框架下的第一性原理平面波超软赝势方法,建立了未掺杂单胞和两种不同掺杂S原子浓度的锐钛矿TiO2模型,分别对模型进行了几何结构优化、态密度分布、能带分布、差分电荷密度分布、集居数和吸收光谱的计算.结果发现:掺杂后... 基于密度泛函理论框架下的第一性原理平面波超软赝势方法,建立了未掺杂单胞和两种不同掺杂S原子浓度的锐钛矿TiO2模型,分别对模型进行了几何结构优化、态密度分布、能带分布、差分电荷密度分布、集居数和吸收光谱的计算.结果发现:掺杂后O原子2p态、S原子3p态和Ti原子3d态在导带内发生了强烈的杂化耦合作用,Ti原子3d态的电子向S原子3p态转移,引起导带下移;O原子2p态和S原子3p态在价带中杂化耦合作用,引起价带上移,引起了带隙变窄发生红移现象,同时,高掺杂S原子浓度越高红移越显著,计算结果与实验结果相一致. 展开更多
关键词 s高掺杂锐钛矿TiO2 电子结构 红移 第一性原理
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Detection of Casimir Radiation from Our Sun 被引量:2
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作者 Richard A. Hutchin 《Optics and Photonics Journal》 2019年第9期141-154,共14页
This paper extends the previous experimental work on Planck’s constant h and the vacuum field, whose spectrum is determined by h. In particular it adds additional experimental evidence supporting temporal and spatial... This paper extends the previous experimental work on Planck’s constant h and the vacuum field, whose spectrum is determined by h. In particular it adds additional experimental evidence supporting temporal and spatial variations in the vacuum field, including the Sun as a source at 13 sigmas of certainty. The vacuum field has long been a mystery of physics, having enormous theoretical intensity set by Planck’s constant h and yet no obvious physical effect. Hendrick Casimir first proposed that this form of E & M radiation was real in 1948 and suggested an experiment to verify its existence. Over 50 experiments since then have confirmed that this vacuum radiation is real, is a form of electro-magnetic radiation, and varies in time and space over 10:1 in our laboratory compared to its standard QM spectrum. Two other authors have found the fine structure constant α (proportional to 1/h) is varying across the cosmos at up to 4.2 sigma certainty. All these results suggest that the vacuum field (and thus h) varies in time and space. In a previous paper we reported our tunnel diode experimental results as well as the results of six other organizations (including German, Russian and US national labs).The six organizations reported sinusoidal annual variations of 1000 - 3000 ppm (peak-to-valley) in the decay rates of 8 radionuclides over a 20-year span, including beta decay (weak interaction) and alpha decay (strong interaction). All decay rates peaked in January-February and minimized in July-August without any candidate cause suggested. We confirmed that Planck’s constant was the cause by verifying similar variations in Esaki tunnel diode current, which is purely electromagnetic. The combined data from previous strong and weak decays plus our own E & M tunnel data showed similar magnitude and time phasing for strong, weak and E & M interactions, except that the tunnel diode temporal variations were 180 deg out of phase—as we predicted. The logic for this 180 deg phase shift was straight forward. Radioactive decay and electron tunneling both have h in the denominator of the tunneling exponent, but tunnel diodes also have h2 in the numerator of the exponent due to the size of atoms being proportional to h2. This extra h2 makes the exponent proportional to h for electron tunneling instead of proportional to 1/h for strong and weak decay—shifting the annual oscillation for E & M tunnel current by 180 deg. Radioactive decay had a maximum around January-February of each year and a minimum around July-August of each year. Tunnel current (the equivalent to radioactive decay rate) had the opposite—a minimum around January of each year and a maximum around July of each year. This predicted and observed sign flip in the temporal variations between radioactive decay and electron tunneling provides strong evidence that h variations across the Earth’s orbit are the cause of these annual cycles. In this paper we take the next step by verifying whether the Sun and a potential more distant cosmic source radiate the vacuum E & M field, just as all stars generate massive amounts of regular E & M radiation. We reprocessed two years of data, 6 million data points, from our tunnel diode experiment to search for day-night oscillations in tunnel current. Here we assume that the Earth would block the radiated vacuum field half of each day. Sun-locked signals have 365 cycles per year and cosmos locked signals have 366 cycles per year. With our two years of data, these two signals are separated by a null-signal, which is not locked to the Earth or to the cosmos—allowing us to clearly distinguish the solar and cosmic sources. 1) We found sun-locked variations in the vacuum field, peaking around local noon with 10-13 probability of false alarm. Other potential causes are carefully examined and ruled out. 2) We also found cosmos-locked variations in the vacuum field, peaking at the right ascension of the red super-giant star Betelgeuse with 10-7 probability of false alarm. Cosmos locked sources are easily distinguished from the solar source because they have one extra cycle per year, two extra cycles during the two years of the experiment. They are thus independent Fourier components, easily separated by a Fourier transform. Both of these high probability detections support that the vacuum field spectrum may vary in space and time and be enhanced by stellar sources. 展开更多
关键词 Planck’s CONsTANT VARIABLE RADIOACTIVE Decay Rate VARIABLE Plank’s CONsTANT solar RADIATION CAsIMIR RADIATION COsMIC red shift
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On the Metric of Space-Time
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作者 Carl E. Wulfman 《Journal of Modern Physics》 2013年第11期1511-1518,共8页
Maxwell’s equations are obeyed in a one-parameter group of isotropic gravity-free flat space-times whose metric depends upon the value of the group parameter. An experimental determination of this value has been prop... Maxwell’s equations are obeyed in a one-parameter group of isotropic gravity-free flat space-times whose metric depends upon the value of the group parameter. An experimental determination of this value has been proposed. If it is zero, the metric is Minkowski’s. If it is non-zero, the metric is not Poincare invariant and local frequencies of electromagnetic waves change as they propagate. If the group parameter is positive, velocity-independent red-shifts develop and the group parameter play a role similar to that of Hubble’s constant in determining the relation of these red-shifts to propagation distance. In the resulting space-times, the velocity-dependence of red shifts is a function of propagation distance. If 2c times the group parameter and Hubble’s constant have approximately the same value, observed frequency shifts in radiation received from stellar sources can imply source velocities quite different from those implied in Minkowski space. Electromagnetic waves received from bodies in galactic Kepler orbits undergo frequency shifts which are indistinguishable from shifts currently attributed to dark matter and dark energy in Minkowski space, or to a non-Newtonian physics. 展开更多
关键词 sPACE-TIME METRIC hubble DARK Matter red shift AsTROPHYsICs ELECTRODYNAMICs
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Model of Universe as Described by Dynamic Universe Model
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作者 Satyavarapu Naga Parameswara Gupta 《Open Journal of Modelling and Simulation》 2019年第1期41-78,共38页
In this paper we will see the model of Universe according to Dynamic Universe Model of Cosmology by visualizing various processes that are happening in the Universe as per experimental evidences. For simplifying the m... In this paper we will see the model of Universe according to Dynamic Universe Model of Cosmology by visualizing various processes that are happening in the Universe as per experimental evidences. For simplifying the matter here, we will see in part 1: about the Galaxy life cycle, where the birth and death of Galaxies discussed. Probably Universe gives guidance for the movement of Galaxies. We call this Part 1: Thinking and Reproducing Universe or Mindless Universe? (Galaxy life cycle). We see every day Sun, Stars, Galaxies etc., dissipating enormous energy in the form of radiation by the way of fusion of Hydrogen to helium. So after sometime all the Hydrogen is spent and Universe will die, is it not? … Dynamic Universe Model says that the energy in the form of electromagnetic radiation passing grazingly near any gravitating mass changes in frequency and finally will convert into neutrinos (mass). Hence Dynamic Universe Model proposes another process where energy will be converted back into matter and the cycle energy to mass to energy continues, sustaining the Universe to maintain this present status for ever in this form something like a Steady state model without any expansion. This we will see in Part 2: Energy - Mass - Energy Cycle. After converting energy into mass “how various elements are formed and where they are formed?” will be next logical question. Dynamic Universe Model says that these various particles change into higher massive particles or may get bombarded into stars or planets and various elements are formed. Here we bifurcate the formation of elements into 6 processes. They are for Elementary particles and elements generated in frequency changing process, By Cosmic rays, By Small stars, By Large Stars, By Super Novae and Manmade elements By Neutron Stars. This we will discuss in Part 3: Nucleosynthesis. 展开更多
关键词 DYNAMIC UNIVERsE MODEL hubble space Telescope (HsT) sITA simulations (sITA-simulation of Inter Intra Tautness Attraction Forces Used by DYNAMIC UNIVERsE Model) singularity-Free COsMOLOGY Blue shifted GALAXIEs red shifted GALAXIEs Grazing Radiation Frequency Changes Formation of Elements Nucleosynthesis DYNAMIC UNIVERsE MODEL Energy to Mass Conversion Methods: N-Body simulations-Gravitation-Cosmology
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“大爆炸宇宙学”批评 被引量:2
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作者 黄志洵 《中国传媒大学学报(自然科学版)》 2015年第1期4-19,共16页
大爆炸宇宙创生理论是以天文学家Hubble的观测为基础的,他声称已发现那些遥远的天体正远离我们而去。此即Hubble氏的宇宙扩张理论。但该理论的证据并不充分,是主观想像。宇宙爆炸理论的另一重要证据是微波背景辐射的测量数据,但它并不... 大爆炸宇宙创生理论是以天文学家Hubble的观测为基础的,他声称已发现那些遥远的天体正远离我们而去。此即Hubble氏的宇宙扩张理论。但该理论的证据并不充分,是主观想像。宇宙爆炸理论的另一重要证据是微波背景辐射的测量数据,但它并不表示微波背景辐射温度数据一定是一次爆炸后的结果。把它看成一次原初大爆炸的余烬是勉强的。按照宇宙的定义,人们无法谈论"宇宙寿命",只可能谈论诸如"地球的寿命"、"太阳系的寿命"和"星系的寿命"。因此我们反对不靠谱的大爆炸宇宙学,因该理论体系漏洞百出,在科学上和在哲学上均不能成立。虽然宇宙中看来充满难于解释的力,暗物质和暗能量仍然只是两个假设。另一个假说是存在引力波,但也只是估计,实际情况可能不同。在Newton理论中引力速度是无限大,但在Einstein理论中引力传播速度和引力波波速都是光速c。广义相对论(GR)认为引力与电磁力不同,是弯曲时空的纯几何效应。但现在应思索某些不同的引力模型,例如把引力重新当作平直时空中的自然界的力的传播,从而又研究得出引力速度大于2×1010c(c是真空中光速)。虽然超光速的引力传播违反Einstein的狭义相对论(SR),却符合Lorentz的相对性理论(LR)。在美国,一个宇宙学家团队在2014年3月的一次新闻发布会上宣布,他们探测到了宇宙大爆炸之后最初瞬间所产生的引力波,从而导致宇宙的起源再次成为重大新闻。根据BICEP2南极望远镜团队的信息,其结果被誉为大爆炸暴涨理论及其后续理论(多元宇宙)的证明。该成果问鼎Nobel奖也在预测之中。BICEP2团队在其宇宙微波背景辐射极化图像中,确定了一个扭曲(B模式)图案,绪论是检测到原始的引力波。但在后来数月中,由来自Princeton大学和也在Princeton高等研究所的科学家们进行了认真的重新分析,其结论是BICEP2的B模式模型给出的大部分或全部最显著效应没有来自引力波的任何贡献。这种突然逆转应该让科学界认真考虑未来的宇宙学实验和理论。BICEP2事件也揭示了一个关于暴涨理论的真相;很清楚,暴涨范式是根本无法检验的,并因此在科学上是毫无意义的。 展开更多
关键词 大爆炸宇宙学 hubble红移 微波背景辐射 暗能量 引力波 暴涨理论
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卫星导航和惯性导航与时间和空间的理论
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作者 林金 《宇航学报》 EI CAS CSCD 北大核心 2011年第4期829-834,共6页
从卫星导航和惯性导航的测速定位机理分析出发讨论了时间和空间理论的有关基本问题。提供了一种卫星导航的原理完备的观测方程形式,包括惯性和非惯性物理效应。着重讨论了洛伦兹一次项的效应,伽里略变换自然进化到洛伦兹变换,"同地... 从卫星导航和惯性导航的测速定位机理分析出发讨论了时间和空间理论的有关基本问题。提供了一种卫星导航的原理完备的观测方程形式,包括惯性和非惯性物理效应。着重讨论了洛伦兹一次项的效应,伽里略变换自然进化到洛伦兹变换,"同地性"的相对性自然导致"同时性"的相对性。从卫星导航的单程光(电磁)信号的特点出发讨论了爱因斯坦"往"和"返"双程光信号定义带来的困惑。指出哈勃红移是超低速度和超大距离的狭义相对论效应验证。用爱因斯坦对惯性质量和引力质量等效原理的论述,论证了惯性导航的理论基础和超过3×108m/s的速度测量机理。 展开更多
关键词 卫星导航 惯性导航 时间和空间 洛伦兹一次项效应 哈勃红移
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中央红军长征前的军事经济准备 被引量:1
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作者 杜人淮 《军事历史研究》 CSSCI 2017年第2期74-85,共12页
1934年4月广昌保卫战失利后,中共中央主要领导开始考虑中央红军战略转移问题,并为中央红军撤离苏区进行战略转移着手进行军事经济等准备工作。这方面的准备工作大致可分为两个阶段。第一阶段为中央红军战略转移的举棋不定和军事经济准... 1934年4月广昌保卫战失利后,中共中央主要领导开始考虑中央红军战略转移问题,并为中央红军撤离苏区进行战略转移着手进行军事经济等准备工作。这方面的准备工作大致可分为两个阶段。第一阶段为中央红军战略转移的举棋不定和军事经济准备的酝酿及实施,时间为1934年5月到8月底。此阶段的军事经济准备,既是出于中央红军主力必要时撤离中央苏区的需要,更是出于用武力继续捍卫中央苏区的需要。第二阶段是中共中央最终决定中央红军突围转移和军事经济准备的紧急部署与展开,时间为1934年9月初到10月中下旬。此阶段中共中央最终决定中央红军实施突围转移,并秘密部署与展开军事经济准备的相关工作。中国共产党作为共产国际的一个支部,中央红军实施战略转移及为此所进行的军事经济准备受到了共产国际的深刻影响。 展开更多
关键词 中央红军 战略转移 军事经济准备 红军长征 共产国际
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