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Influence of topography on the fine structures of stratospheric gravity waves:An analysis using COSMIC-2 temperature data 被引量:1
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作者 JiaRui Wei Xiao Liu +2 位作者 JiYao Xu QinZeng Li Hong Gao 《Earth and Planetary Physics》 EI CAS CSCD 2024年第3期497-513,共17页
We derive the potential energy of gravity waves(GWs)in the upper troposphere and stratosphere at 45°S-45°N from December 2019 to November 2022 by using temperature profiles retrieved from the Constellation O... We derive the potential energy of gravity waves(GWs)in the upper troposphere and stratosphere at 45°S-45°N from December 2019 to November 2022 by using temperature profiles retrieved from the Constellation Observing System for Meteorology,Ionosphere,and Climate-2(COSMIC-2)satellite.Owing to the dense sampling of COSMIC-2,in addition to the strong peaks of gravity wave potential energy(GWPE)above the Andes and Tibetan Plateau,we found weak peaks above the Rocky,Atlas,Caucasus,and Tianshan Mountains.The land-sea contrast is responsible for the longitudinal variations of the GWPE in the lower and upper stratosphere.At 40°N/S,the peaks were mainly above the topographic regions during the winter.At 20°N/S,the peaks were a slight distance away from the topographic regions and might be the combined effect of nontopographic GWs and mountain waves.Near the Equator,the peaks were mainly above the regions with the lowest sea level altitude and may have resulted from convection.Our results indicate that even above the local regions with lower sea level altitudes compared with the Andes and Tibetan Plateau,the GWPE also exhibits fine structures in geographic distributions.We found that dissipation layers above the tropopause jet provide the body force to generate secondary waves in the upper stratosphere,especially during the winter months of each hemisphere and at latitudes of greater than 20°N/S. 展开更多
关键词 TOPOGRAPHY fine structures stratospheric gravity waves Constellation Observing System for Meteorology Ionosphere and Climate-2(COSMIC-2) dissipation layers
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Quick-scanning X-ray absorption fine structure beamline at SSRF
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作者 Yu Chen Qian Gao +2 位作者 Zheng Jiang Jiong Li Shuo Zhang 《Nuclear Science and Techniques》 SCIE EI CAS CSCD 2024年第6期1-13,共13页
The layout and characteristics of the hard X-ray spectroscopy beamline(BL11B)at the Shanghai synchrotron radiation facility are described herein.BL11B is a bending-magnet beamline dedicated to conventional and millise... The layout and characteristics of the hard X-ray spectroscopy beamline(BL11B)at the Shanghai synchrotron radiation facility are described herein.BL11B is a bending-magnet beamline dedicated to conventional and millisecond-scale quick-scanning X-ray absorption fine structures.It is equipped with a cylindrical collimating mirror,a double-crystal monochromator comprising Si(111)and Si(311),a channel-cut quick-scanning Si(111)monochromator,a toroidal focusing mirror,and a high harmonics rejection mirror.It can provide 5-30 keV of X-rays with a photon flux of~5×10^(11)photons/s and an energy resolution of~1.31×10^(-4)at 10 keV.The performance of the beamline can satisfy the demands of users in the fields of catalysis,materials,and environmental science.This paper presents an overview of the beamline design and a detailed description of its performance and capabilities. 展开更多
关键词 Bending magnet beamline X-ray absorption fine structure Quick-scanning XAFS In situ Synchrotron radiation
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Fine and hyperfine structures of pionic helium atoms
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作者 白志达 钟振祥 +1 位作者 严宗朝 史庭云 《Chinese Physics B》 SCIE EI CAS CSCD 2023年第2期236-241,共6页
The fine and hyperfine structures of pionic helium metastable states is calculated within the formalism of the Breit-Pauli Hamiltonian by using the variationally generated wave functions in Hylleraas coordinates.Our r... The fine and hyperfine structures of pionic helium metastable states is calculated within the formalism of the Breit-Pauli Hamiltonian by using the variationally generated wave functions in Hylleraas coordinates.Our results not only verify the existing values of Hori et al.[Phys.Rev.A 89,042515(2014)]for the fine structure of π^(4)He^(+),but also determine the hyperfine structure of π^(3)He^(+). 展开更多
关键词 exotic atom pionic helium fine structure hyperfine structure
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An Electron Model Based on the Fine Structure Constant
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作者 Arlen Young 《Journal of Modern Physics》 CAS 2023年第5期553-561,共9页
In previous publications, the author has proposed a model of the electron’s internal structure, wherein a positively-charged negative mass outer shell and a negatively-charged positive mass central core are proposed ... In previous publications, the author has proposed a model of the electron’s internal structure, wherein a positively-charged negative mass outer shell and a negatively-charged positive mass central core are proposed to resolve the electron’s charge and mass inconsistencies. That model is modified in this document by assuming the electron’s radius is exactly equal to the classical electron radius. The attributes of the internal components of the electron’s structure have been recalculated accordingly. The shape of the electron is also predicted, and found to be slightly aspherical on the order of an oblate ellipsoid. This shape is attributed to centrifugal force and compliant outer shell material. It is interesting to note that all of the electron’s attributes, both external and internal, with the exception of mass and angular moment, are functions of the fine structure constant a, and can be calculated from just three additional constants: electron mass, Planck’s constant, and speed of light. In particular, the ratios of the outer shell charge and mass to the electron charge and mass, respectively, are 3/2a. The ratios of the central core charge and mass to the electron charge and mass, respectively, are 1-(3/2a). Attributes of the electron are compared with those of the muon. Charge and spin angular momentum are the same, while mass, magnetic moment, and radius appear to be related by the fine structure constant. The mass of the electron outer shell is nearly equal to the mass of the muon. The muon internal structure can be modeled exactly the same as for the electron, with exactly the same attribute relationships. 展开更多
关键词 fine structure Constant Negative Mass Electron Shape Electron structure Electron Mass Inconsistency Electron Charge Inconsistency MUON
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On the Fine Structure and the Other Coupling Constants at the Planck Scale
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作者 Paolo Christillin 《Journal of Modern Physics》 CAS 2023年第5期666-669,共4页
It is shown that the fine structure constant at Planck times tends to one as well as those of the weak and strong interactions. This results by constraining them at the Planck force. That seems to provide interesting ... It is shown that the fine structure constant at Planck times tends to one as well as those of the weak and strong interactions. This results by constraining them at the Planck force. That seems to provide interesting new results which confirm that at the beginning of space time (Planck scale) all fundamental forces converge to the same unit value. 展开更多
关键词 fine structure Constant Fundamental Interactions Coupling Constants Unification at Planck Scale
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A Conceptual Model of Our Universe Derived from the Fine Structure Constant (α)
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作者 John R. Crary 《American Journal of Computational Mathematics》 2023年第4期524-532,共9页
The Fine Structure Constant (α) is a dimensionless value that guides much of quantum physics but with no scientific insight into why this specific number. The number defines the coupling constant for the strength of ... The Fine Structure Constant (α) is a dimensionless value that guides much of quantum physics but with no scientific insight into why this specific number. The number defines the coupling constant for the strength of the electromagnetic force and is precisely tuned to make our universe functional. This study introduces a novel approach to understanding a conceptual model for how this critical number is part of a larger design rather than a random accident of nature. The Fine Structure Constant (FSC) model employs a Python program to calculate n-dimensional property sets for prime number universes where α equals the whole number values 137 and 139, representing twin prime universes without a fractional constant. Each property is defined by theoretical prime number sets that represent focal points of matter and wave energy in their respective universes. This work aims to determine if these prime number sets can reproduce the observed α value, giving it a definable structure. The result of the FSC model produces a α value equal to 137.036, an almost exact match. Furthermore, the model indicates that other twin prime pairs also have a role in our functional universe, providing a hierarchy for atomic orbital energy levels and alignment with the principal and azimuthal quantum numbers. In addition, it construes stable matter as property sets with the highest ratio of twin prime elements. These results provide a new perspective on a mathematical structure that shapes our universe and, if valid, has the structural complexity to guide future research. 展开更多
关键词 fine structure Constant Conceptual Model Prime Numbers Property Sets Quantum PHYSICS UNIVERSE
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Comparative Studies on the Fine Structure and Elemental Composition of Envelopes of Trachelomonas and Strombomonas (Euglenophyta) 被引量:1
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作者 王全喜 刘洪家 +3 位作者 于晶 孙世琴 张大维 包文美 《Acta Botanica Sinica》 CSCD 2003年第5期601-607,共7页
Fine structure and elemental composition of envelopes of 10 taxa of Trachelomonas and Strombomonas from natural freshwater bodies in China were studied and phylogeny of both genera were discussed. The results indicate... Fine structure and elemental composition of envelopes of 10 taxa of Trachelomonas and Strombomonas from natural freshwater bodies in China were studied and phylogeny of both genera were discussed. The results indicate that iron (Fe) and silicon (Si) are the primary mineral elements of the envelopes. Composition of mineral elements was uncorrelated with envelope color, however, it was highly correlated with the microarchitecture of the envelopes. Content of Si was higher than that of Fe in all species of Strombomonas and some species of Trachelomonas with rough surface. In most species of Trachelomonas, especially those with dense and smoothy surface, content of Fe was higher than that of Si. Based on the above results, we propose to assign those species of Strombomonas into Trachelomonas and consider them as a group of the latter. These species were the most primitive among the group with envelopes in Euglenaceae. 展开更多
关键词 Trachelomonas Strombomonas ENVELOPE elemental composition fine structure
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Periodic oscillation and fine structure of wedge-induced oblique detonation waves 被引量:11
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作者 Ming-Yue Gui Bao-Chun Fan Gang Dong 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 2011年第6期922-928,共7页
An oblique detonation wave for a Mach 7 inlet flow over a long enough wedge of 30 turning angle is simulated numerically using Euler equation and one-step rection model.The fifth-order WENO scheme is adopted to captur... An oblique detonation wave for a Mach 7 inlet flow over a long enough wedge of 30 turning angle is simulated numerically using Euler equation and one-step rection model.The fifth-order WENO scheme is adopted to capture the shock wave.The numerical results show that with the compression of the wedge wall the detonation wave front structure is divided into three sections:the ZND model-like strcuture,single-sided triple point structure and dual-headed triple point strucuture.The first structure is the smooth straight,and the second has the characteristic of the triple points propagating dowanstream only with the same velocity,while the dual-headed triple point structure is very complicated.The detonation waves facing upstream and downstream propagate with different velocities,in which the periodic collisions of the triple points cause the oscillation of the detonation wave front.This oscillation process has temporal and spatial periodicity.In addition,the triple point trace are recorded to obtain different cell structures in three sections. 展开更多
关键词 Oblique detonation wave Wedge - Periodic oscillation fine structure
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MICROSTRUCTURE TRANSFORMATION IN THE WELDING HEAT AFFECTED ZONE OF 800MPa GRADE ULTRA FINE STRUCTURED STEEL 被引量:1
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作者 J.B. Liu L.J. Hu +3 位作者 Y.T.Wang Z. Q. Liu K. Miao Z.L. Tian 《Acta Metallurgica Sinica(English Letters)》 SCIE EI CAS CSCD 2004年第3期238-246,共9页
The transformation behavior and microstructure development in the heat affected zone(HAZ)of 800MPa grade ultra fine structured steel was investigated.It was found that the HAZ has intermediate temperature transformati... The transformation behavior and microstructure development in the heat affected zone(HAZ)of 800MPa grade ultra fine structured steel was investigated.It was found that the HAZ has intermediate temperature transformation characteristics in a wide range of cooling rates,with the bainite sheaves consisting of bainite ferrite plates without carbide precipitation and retained austenite in the fast cooling regime.At relatively high cooling rates,which corresponded to low heat inputs,the hardness of the simulated HAZ was above that of the base metal.When the cooling rate was below 9C/s,the welding HAZ would have an obvious softening.The analysis of transformation rates in continuous cooling processes was completed by numerical differential method.The result indicated that the microstructure transformation rate of the HAZ in 800MPa grade ultra fine structured steel changed sharply to slow speeds when the cooling time t8/5 is longer than 7s. 展开更多
关键词 ultra fine structured steel WELD heat affected zone transformation rate microstructure
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Precision calculation of fine structure in helium and Li^+ 被引量:1
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作者 张佩佩 钟振祥 +1 位作者 严宗朝 史庭云 《Chinese Physics B》 SCIE EI CAS CSCD 2015年第3期111-117,共7页
The fine structure constant α can be extracted from high-precision spectroscopy of the 2^3 P J fine structure splittings in helium and light helium-like ions. In this work, the 2^3 P J fine structure splittings of he... The fine structure constant α can be extracted from high-precision spectroscopy of the 2^3 P J fine structure splittings in helium and light helium-like ions. In this work, the 2^3 P J fine structure splittings of helium and Li^+ ion are calculated,including relativistic and QED corrections of order mα^4, mα^4(m/M), mα^5, mα^5(m/M), and Douglas–Kroll operators of mα^6 and mα^6(m/M), which provide an independent verification for the previous calculations performed by Drake [Can.J. Phys. 80 1195(2002)] and by Pachucki and Yerokhin [Phys. Rev. A 79 062516(2009); Phys. Rev. Lett. 104 070403(2010); Can. J. Phys. 89 1139(2011)]. The results of the three groups agree with each other. 展开更多
关键词 fine structure HELIUM Li^+ ion QED theory
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Shell-driven Fine Structure Transition of Core Materials in Co@Au Core-shell Nanoparticles 被引量:1
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作者 Yujun Song Yinghui Wang +1 位作者 Shaoxia Ji Jie Ding 《Nano-Micro Letters》 SCIE EI CAS 2012年第4期235-242,共8页
Co@Au core shell nanoparticles(NPs) of different shell thicknesses were fabricated by a combination of the displacement process and the reduction-deposition process in a microfluidic reactor. The effect of the shell t... Co@Au core shell nanoparticles(NPs) of different shell thicknesses were fabricated by a combination of the displacement process and the reduction-deposition process in a microfluidic reactor. The effect of the shell thickness on the fine structures(local atom arrangement) of core materials was investigated by X-ray Absorption Near Edge Structure(XANES) and Extended X-ray Absorption Fine Structure(EXAFS).The results indicate that the shell thickness affects the fine structure of the core materials by causing atomic re-arrangement between the hexagonal close pack(hcp) and the face centered cubic(fcc) structure, and forming Co-Au bonds in the core-shell interface. 展开更多
关键词 NANOPARTICLE CORE-SHELL fine structure Microfluidic
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A New Theory on the Origin and Nature of the Fine Structure Constant 被引量:3
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作者 Nader Butto 《Journal of High Energy Physics, Gravitation and Cosmology》 2020年第4期579-589,共11页
The nature and the origin of the fine structure are described. Based on the vortex model and hydrodynamics, a comprehensible interpretation of the fine structure constant is developed. The vacuum considered to have su... The nature and the origin of the fine structure are described. Based on the vortex model and hydrodynamics, a comprehensible interpretation of the fine structure constant is developed. The vacuum considered to have superfluid characteristics and elementary particles such as the electron and Hydrogen molecule are irrotational vortices of this superfluid. In such a vortex, the angular rotation ω is maintained, and the larger the radius, the slower the rotational speed. The fine structure value is derived from the ratio of the rotational speed of the boundaries of the vortex to the speed of the vortex eye in its center. Since the angular rotation is constant, the same value was derived from the ratio between the radius of the constant vortex core and the radius of the hall vortex. Therefore, the constancy of alpha is an expression of the constancy relation in the vortex structure. 展开更多
关键词 fine structure Constant Angular Rotation Irrotational Vortex Vortex Electron structure Hydrogen Atom structure
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Possible radio precursors/signatures of the CMEs onset:radio type Ⅲ bursts and fine structures in the centimeter-metric wavelength region 被引量:2
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作者 MinWang Guan-NanGa01 +1 位作者 Rui-XiangXie Cheng-MingTan 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2011年第5期607-616,共10页
Seventy-one occurrences of coronal mass ejections (CMEs) associated with radio bursts, seemingly associated with type III bursts/fine structures (FSs), in the centimeter-metric frequency range during 2003-2005, we... Seventy-one occurrences of coronal mass ejections (CMEs) associated with radio bursts, seemingly associated with type III bursts/fine structures (FSs), in the centimeter-metric frequency range during 2003-2005, were obtained with the spectrometers at the National Astronomical Observatories, Chinese Academy of Sciences (NAOC) and the Culgoora radio spectrometer and are presented. The statistical results of 68 out of 71 events associated with the radio type III bursts or FSs during the initiation or early stages of the CMEs indicate that most CMEs contain the emissions of radio type III bursts/FSs near the time of the CME's onset, in spite of their fast or slow speeds. Therefore, we propose that type III bursts and FSs are possible precursors of the onset of CMEs. We stress that the radio type III bursts/FSs in the centimetermetric wavelength region and the CME transients possibly occurred in conjunction with the origin of the coronal precursor structures. Thus, the statistical results support the suggestions that type III bursts/FSs are indicators of extra energy input into the corona at the CMEs' onset, and that the type III bursts/FSs are produced primarily due to a coronal instability which eventually triggers the CME process. This may signify that the centimeter-metric radio bursts corresponding to or near the CME's onset are caused by the disturbed corona (possibly including minor magnetic reconnections). 展开更多
关键词 Sun: radio burst - radio fine structure -coronal mass ejection
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Calculation of <i>G</i>Gravity Constant from the Mass and Electron Charge, and Fine Structure Constant 被引量:1
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作者 Valentino Straser 《Journal of Modern Physics》 2021年第8期1172-1181,共10页
This study proposes, from the theoretical point of view, the calculation of the gravitational constant <em>G</em>, made starting from the charge and the electron mass, taking the constant of the Fine Struc... This study proposes, from the theoretical point of view, the calculation of the gravitational constant <em>G</em>, made starting from the charge and the electron mass, taking the constant of the Fine Structure into examination. In the empty space, couples of virtual positron electrons dematerialize, giving virtual photon origin. They, at their time, will become electrons, positrons and so on. These transformations are made keeping the board of their “amount of movement” and when they meet the matter, these couples come, reissued depending on the field and on the matter mass. The matter is the change of the trend of their gyromagnetic movement relationship which puts under pressure. In presence of two masses, this gyromagnetic movement relationship is already partially oriented towards the other mass. From here a force is established between these two masses that give as calculated constant equal to 6.678532. This value of <em>G</em>, obtained leaving from the charge and the electron mass, is very near the experimental values estimated in these last decades regard the value of the gravitational constant of <em>G</em>. 展开更多
关键词 ELECTRON POSITRON Gravitational Constant String Theory Theory of Everything fine structure Constant
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Evaluation of the Fine Structure Constant 被引量:1
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作者 Adriano Alippi 《Journal of Modern Physics》 2020年第12期1918-1925,共8页
An equation is given for analytically defining the value of the fine structure constant, whose derivation follows two main steps, relative to the generation of electric charges and to the polarizability of vacuum due ... An equation is given for analytically defining the value of the fine structure constant, whose derivation follows two main steps, relative to the generation of electric charges and to the polarizability of vacuum due to virtual dipoles. The obtained value matches the experimental one by a factor lower than the relative standard uncertainty produced by the National Institute of Standards and Technology (NIST). 展开更多
关键词 fine structure Constant Virtual Particles Vacuum Permittivity
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Fundamental Harmonic Power Laws Relating the Frequency Equivalents of the Electron, Bohr Radius, Rydberg Constant with the Fine Structure, Planck’s Constant, 2 and π 被引量:1
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作者 Donald William Chakeres 《Journal of Modern Physics》 2016年第13期1801-1810,共10页
We evaluate three of the quantum constants of hydrogen, the electron, e<sup>-</sup>, the Bohr radius, a<sub>0</sub>, and the Rydberg constants, , as natural unit frequency equivalents, v. This ... We evaluate three of the quantum constants of hydrogen, the electron, e<sup>-</sup>, the Bohr radius, a<sub>0</sub>, and the Rydberg constants, , as natural unit frequency equivalents, v. This is equivalent to Planck’s constant, h, the speed of light, c, and the electron charge, e, all scaled to 1 similar in concept to the Hartree atomic, and Planck units. These frequency ratios are analyzed as fundamental coupling constants. We recognize that the ratio of the product of 8π<sup>2</sup>, the v<sub>e</sub><sub>-</sub> times the v<sub>R</sub> divided by v<sub>a</sub><sub>0</sub> squared equals 1. This is a power law defining Planck’s constant in a dimensionless domain as 1. We also find that all of the possible dimensionless and dimensioned ratios correspond to other constants or classic relationships, and are systematically inter-related by multiple power laws to the fine structure constant, α;and the geometric factors 2, and π. One is related to an angular momentum scaled by Planck’s constant, and another is the kinetic energy law. There are harmonic sinusoidal relationships based on 2π circle geometry. In the dimensionless domain, α is equivalent to the free space constant of permeability, and its reciprocal to permittivity. If any two quanta are known, all of the others can be derived within power laws. This demonstrates that 8π2 represents the logical geometric conversion factor that links the Euclid geometric factors/three dimensional space, and the quantum domain. We conclude that the relative scale and organization of many of the fundamental constants even beyond hydrogen are related to a unified power law system defined by only three physical quanta of v<sub>e</sub><sub>-</sub>, v<sub>R</sub>, and v<sub>a</sub><sub>0</sub>. 展开更多
关键词 Fundamental Physical Constants Unification Models Hydrogen ELECTRON Bohr Radius Rydberg Constant fine structure Constant
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Extended X-ray absorption fine structure (EXAFS) of FAPbI_(3) for understanding local structure-stability relation in perovskite solar cells
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作者 Dong-Ho Kang Yong-Jun Park +1 位作者 Yun-Sung Jeon Nam-Gyu Park 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2022年第4期549-554,共6页
Perovskite solar cells (PSCs) employing formamidinium lead iodide (FAPbI_(3)) have shown high efficiency.However,operational stability has been issued due to phase instability of α phase FAPbI_(3) at ambient temperat... Perovskite solar cells (PSCs) employing formamidinium lead iodide (FAPbI_(3)) have shown high efficiency.However,operational stability has been issued due to phase instability of α phase FAPbI_(3) at ambient temperature.Excess precursors in the perovskite precursor solution has been proposed to improve not only power conversion efficiency (PCE) but also device stability.Nevertheless,there is a controversial issue on the beneficial effect on PCE and/or stability between excess FAI and excess PbI_(2).We report here extended X-ray absorption fine structure (EXAFS) of FAPbI_(3) to study local structural change and explain the effect of excess precursors on photovoltaic performance and stability.Perovskite films prepared from the precursor solution with excess PbI_(2)shows better stability than those from the one with excess FAI,despite similar PCE.A rapid phase transition from α phase to non-perovskite δ phase is observed from the perovskite film formed by excess FAI.Furthermore,the (Pb-I) bond distance evaluated by the Pb L_(III)-edge EXAFS study is increased by excess FAI,which is responsible for the phase transition and poor device stability.This work can provide important insight into local structure-stability relation in the FAPbI_(3)-based PSCs. 展开更多
关键词 Extended X-ray absorption fine structure EXAFS Excess precursor Local structure STABILITY Perovskite solar cells
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Fine structure and phase composition of Fe–14Mn–1.2C steel:influence of a modified mixture based on refractory metals
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作者 Anna Zykova Natalya Popova +1 位作者 Mark Kalashnikov Irina Kurzina 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2017年第5期523-529,共7页
The effect of TiO;,ZrO;and Na;AlF;ultrafine powders on the fine structure and the phase composition of Fe–14Mn–1.2C steel was investigated.The introduction of the ultrafine powders into the melt influenced the grain... The effect of TiO;,ZrO;and Na;AlF;ultrafine powders on the fine structure and the phase composition of Fe–14Mn–1.2C steel was investigated.The introduction of the ultrafine powders into the melt influenced the grain size,the quantity,and the character of distribution of nonmetallic inclusions in the railroad frogs.The microstructure of castings was improved significantly because of the refinement of the grain structure and an increase of the grain-boundary area.After the modifying mixture was introduced into the melt,either the microtwins of one or two intersecting systems or the precipitations of ε-martensite of different types,or simultaneously the microtwins and wafers of ε-martensite,were present in each grain. 展开更多
关键词 manganese steel fine structure phase composition refractory metals
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FINE STRUCTURE VARIATION OF 18R MARTENSITE UNDER DEFORMATION IN POLYCRYSTALLINE CuZnAl AI JOY
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作者 ZHU Min LI Guobin YANG Dazhi Dilian University of Technology,Dalian,China Dept.of Materials Engineering,Dalian University of Technology,Dalian 116024,China 《Acta Metallurgica Sinica(English Letters)》 SCIE EI CAS CSCD 1990年第4期300-303,共4页
The transmission electron microscopy has been used to investigate the fine structure variation of 18R martensite under deformation in a polycrvstalline CuZnAl shape memory alloys.It has been found that the strain is g... The transmission electron microscopy has been used to investigate the fine structure variation of 18R martensite under deformation in a polycrvstalline CuZnAl shape memory alloys.It has been found that the strain is gabined by the reorientation of martensite variants in the ini- tial deformation stage.In addition to the result of optical microscopy studies,however,the reorientation is often incomplete and the interfaces among the prior variants still remain.A lot of twins will appear in martensite under enormous deformation,and the twin plane is(001) phane of martensite lattice.The dislocations has also been observed in some regions.In this case,the martensite will lose its thermoelasticitv and the shape memory effect will be damaged. 展开更多
关键词 fine structure shape memory alloy CuZnAl alloy martensitic transformations
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FINE STRUCTURES OF BOTH INTERFACES AND INTERFACIAL REACTION PRODUCTS
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作者 LI Douxing PING Dehai NING Xiaoguang YE Hengqiang Laboratory of Atomic Imaging of Solids,Institute of Metal Research,Academia Sinica,Shenyang.China Professor,Institute of Metal Research,Academia Sinica,Shenyang 110015,China 《Acta Metallurgica Sinica(English Letters)》 SCIE EI CAS CSCD 1993年第1期1-20,共20页
The characteristic of interface depending on the atomic structure exerts an inportant,and sometime controlling,influence on performance of the interacial materials. The present paper reviews the main studies on fine s... The characteristic of interface depending on the atomic structure exerts an inportant,and sometime controlling,influence on performance of the interacial materials. The present paper reviews the main studies on fine structure of both the materials inter- faces and interfacial reaction products in semiconductor uperlattice,metal multilayer ceram- ics and composite materials by mean of selected area electron doffraction patterns and high resolution electron microscopy. The following features of interfaces are reviewed:the orientation relationships;the char- acteristic of steps,facets and ronghness of interfaces;atomic bonding across the interface;the degree of coherency,the structure of misfit dislocations and elastic relaxations at the inter- faces:the presence of defects at the onterfaces:the structure of the interfacial reaction prod- ucts as well as the reaction kinetics and reaetion mechanism. 展开更多
关键词 fine structure of the interfaces interfacial solid state reaction orientation relationship high resolution electron microscopy
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