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
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
The microphase separation extent of biomedical segmented polyetherurethanes were greatly enhanced due to the presence of sulfoalkyl pendant groups contained in the hard segments,and the hard segments were more orderly...The microphase separation extent of biomedical segmented polyetherurethanes were greatly enhanced due to the presence of sulfoalkyl pendant groups contained in the hard segments,and the hard segments were more orderly aggregated through ionic interaction.展开更多
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
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
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
A cluster model is used to calculate electron energy-loss fine structures in crystal. The multiple-scattering self-consistent-field method is employed in the calculation. Our theoretical results of N near K-edge energ...A cluster model is used to calculate electron energy-loss fine structures in crystal. The multiple-scattering self-consistent-field method is employed in the calculation. Our theoretical results of N near K-edge energy loss fine structures in hexagonal GaN crystal are in good agreement with the experimental spectra. Future possible experiments in energy-filtered transmission electron microscopy (EFTEM) are discussed and proposed because our theoretical work can provide clear assignments for transmitted electrons with different energy losses.展开更多
Denote by SFin(v) the set of all integer pairs (t, s) for which there exist three symmetric Latin squares of order v on the same set having fine structure (t, s). We completely determine the set SFin(2n) for a...Denote by SFin(v) the set of all integer pairs (t, s) for which there exist three symmetric Latin squares of order v on the same set having fine structure (t, s). We completely determine the set SFin(2n) for any integer n ≥ 5.展开更多
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
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
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
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
In addition to the tens of millions of medical doses consumed annually around the world,a vast number of nuclear magnetic resonance imaging(MRI)contrast agents are being deployed in MRI research and development,offeri...In addition to the tens of millions of medical doses consumed annually around the world,a vast number of nuclear magnetic resonance imaging(MRI)contrast agents are being deployed in MRI research and development,offering precise diagnostic information,targeting capabilities,and analyte sensing.Superparamagnetic iron oxide nanoparticles(SPIONs)are notable among these agents,providing effective and versatile MRI applications while also being heavy-metal-free,bioconjugatable,and theranostic.We designed and implemented a novel two-pronged computational and experimental strategy to meet the demand for the efficient and rigorous development of SPION-based MRI agents.Our MATLAB-based modeling simulation and magnetic characterization revealed that extremely small maghemite SPIONs in the 1-3 nm range possess significantly reduced transversal relaxation rates(R_(2))and are therefore preferred for positive(T_(1)-weighted)MRI.Moreover,X-ray diffraction and X-ray absorption fine structure analyses demonstrated that the diffraction pattern and radial distribution function of our SPIONs matched those of the targeted maghemite crystals.In addition,simulations of the X-ray near-edge structure spectra indicated that our synthesized SPIONs,even at 1 nm,maintained a spherical structure.Furthermore,in vitro and in vivo MRI investigations showed that our 1-nm SPIONs effectively highlighted whole-body blood vessels and major organs in mice and could be cleared through the kidney route to minimize potential post-imaging side effects.Overall,our innovative approach enabled a swift discovery of the desired SPION structure,followed by targeted synthesis,synchrotron radiation spectroscopic studies,and MRI evaluations.The efficient and rigorous development of our high-performance SPIONs can set the stage for a computational and experimental platform for the development of future MRI agents.展开更多
Due to their high electrical conductivity and layered structure,two dimensional MXene materials are re⁃garded as promising candidates for energy storage applications.However,the relatively low stability and specific c...Due to their high electrical conductivity and layered structure,two dimensional MXene materials are re⁃garded as promising candidates for energy storage applications.However,the relatively low stability and specific ca⁃pacity of MXene materials limit their further utilization.In this study,these issues are addressed using a heterostruc⁃ture strategy via a one-step selenization method to form Mo_(₂)C@MoSe_(₂).Synchrotron radiation X-ray spectroscopic and high-resolution transmission electron microscopy(HRTEM)characterizations revealed the heterostructure consisting of in-situ grown MoSe_(2)on Mo_(2)C MXene.Electrochemical tests proved the heterojunction electrode’s superior rate perfor⁃mance of 289.06 mAh·g^(-1)at a high current density of 5 A·g^(-1)and long cycling stability of 550 mAh·g^(-1)after 900 cycles at 1 A·g^(-1).This work highlights the useful X-ray spectroscopic analysis to directly elucidate the heterojunction structure,providing an effective reference method for probing heterostructures.展开更多
The possible configurations of pyrrole absorbed on a Si(100)surface have been investigated by x-ray photoelectron spectroscopy(XPS)and near-edge x-ray absorption fine structure(NEXAFS)spectra.The C-1s XPS and NEXAFS s...The possible configurations of pyrrole absorbed on a Si(100)surface have been investigated by x-ray photoelectron spectroscopy(XPS)and near-edge x-ray absorption fine structure(NEXAFS)spectra.The C-1s XPS and NEXAFS spectra of these adsorption configurations have been calculated by using the density functional theory(DFT)method and fullcore hole(FCH)approximation to investigate the relationship between the adsorption configurations and the spectra.The result shows that the XPS and NEXAFS spectra are structurally dependent on the configurations of pyrrole absorbed on the Si(100)surface.Compared with the XPS,the NEXAFS spectra are relatively sensitive to the adsorption configurations and can accurately identify them.The NEXAFS decomposition spectra produced by non-equivalent carbon atoms have also been calculated and show that the spectral features vary with the diverse types of carbon atoms and their structural environments.展开更多
The Fine Structure Constant (eFSC) Model attempts to give a classical definition to a magical number that underlies much of quantum physics. The Fine Structure Constant (α) value equal to 137.03599206 represents a di...The Fine Structure Constant (eFSC) Model attempts to give a classical definition to a magical number that underlies much of quantum physics. The Fine Structure Constant (α) value equal to 137.03599206 represents a dimensionless constant that characterizes the strength of the electromagnetic (EM) interaction between subatomic charged particles. Python-generated property counts for the twin prime force F{139/137} show that the adjusted ratio gives a value of α = 137.036. This implies a mathematical framework underlying this constant is based on twin prime numbers and set theory. This study attempts to demonstrate a proof of concept that a hierarchy of fractional twin prime (αII) forces replicates the quantum nature of the universe and is aligned with the Standard Model of Particle Physics. An expanded eFSC Model demonstrates that twin prime forces and their property sets are mathematically viable substitutes for nuclear reactions, as demonstrated for the Beta-minus decay of neutrons into protons. Most significantly, the positive and negative prime numbers define these nuclear reactants and products as positive or negatively charged ions. Furthermore, the eFSC Model provides new insights regarding the hierarchy of EM forces underlying the quantum nature of the universe.展开更多
This study aims to demonstrate a proof of concept for a novel theory of the universe based on the Fine Structure Constant (α), derived from n-dimensional prime number property sets, specifically α = 137 and α = 139...This study aims to demonstrate a proof of concept for a novel theory of the universe based on the Fine Structure Constant (α), derived from n-dimensional prime number property sets, specifically α = 137 and α = 139. The FSC Model introduces a new perspective on the fundamental nature of our universe, showing that α = 137.036 can be calculated from these prime property sets. The Fine Structure Constant, a cornerstone in Quantum Electrodynamics (QED) and Quantum Chromodynamics (QCD), implies an underlying structure. This study identifies this mathematical framework and demonstrates how the FSC model theory aligns with our current understanding of physics and cosmology. The results unveil a hierarchy of α values for twin prime pairs U{3/2} through U{199/197}. These values, represented by their fraction parts α♊ (e.g., 0.036), define the relative electromagnetic forces driving quantum energy systems. The lower twin prime pairs, such as U{3/2}, exhibit higher EM forces that decrease as the twin pairs increase, turning dark when they drop below the α♊ for light. The results provide classical definitions for Baryonic Matter/Energy, Dark Matter, Dark Energy, and Antimatter but mostly illustrate how the combined α♊ values for three adjacent twin primes, U{7/5/3/2} mirrors the strong nuclear force of gluons holding quarks together.展开更多
Previously, we presented several empirical equations using the cosmic microwave background (CMB) temperature. Next, we propose an empirical equation for the fine-structure constant. Considering the compatibility among...Previously, we presented several empirical equations using the cosmic microwave background (CMB) temperature. Next, we propose an empirical equation for the fine-structure constant. Considering the compatibility among these empirical equations, the CMB temperature (Tc) and gravitational constant (G) were calculated to be 2.726312 K and 6.673778 × 10−11 m3∙kg−1∙s−2, respectively. Every equation can be explained numerically in terms of the Compton length of an electron (λe), the Compton length of a proton (λp) and α. Furthermore, every equation can also be explained in terms of the Avogadro number and the number of electrons at 1 C. We show that every equation can be described in terms of the Planck constant. Then, the ratio of the gravitational force to the electric force can be uniquely determined with the assumption of minimum mass. In this report, we describe the algorithms used to explain these equations in detail. Thus, there are no dimension mismatch problems.展开更多
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
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
基金the National Natural Science Foundation of China(Grant Nos.41831073,42174196,and 42374205)the Project of Stable Support for Youth Team in Basic Research Field,Chinese Academy of Sciences(CAS+4 种基金Grant No.YSBR-018)the Informatization Plan of CAS(Grant No.CAS-WX2021PY-0101)the Youth Cross Team Scientific Research project of the Chinese Academy of Sciences(Grant No.JCTD-2021-10)the Open Research Project of Large Research Infrastructures of CAS titled“Study on the Interaction Between Low-/Mid-Latitude Atmosphere and Ionosphere Based on the Chinese Meridian Project.”This work was also supported in part by the Specialized Research Fund and the Open Research Program of the State Key Laboratory of Space Weather.
文摘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.
基金supported by the National Natural Science Foundation of China (Grant Nos. 11974382 and 11474316)the support from NSERC and SHARCnet of Canada
文摘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^(+).
文摘The microphase separation extent of biomedical segmented polyetherurethanes were greatly enhanced due to the presence of sulfoalkyl pendant groups contained in the hard segments,and the hard segments were more orderly aggregated through ionic interaction.
基金Supported by the National Natural Science Foundation of Chinasupported by the National Basic Research Program of the MOST (Grant No.2011CB811403)the CAS-NSFC Key Project (Grant No. 10978006)
文摘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).
文摘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.
文摘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.
基金the National Natural Science Foundation of China ( Grant Nos.19874035, 59831020, 19734030), National 973 Project, National 863 Program, Climbing Project, The Ministry of Science and Technology of China, National High-Tec ICF Committee, the Ministry of
文摘A cluster model is used to calculate electron energy-loss fine structures in crystal. The multiple-scattering self-consistent-field method is employed in the calculation. Our theoretical results of N near K-edge energy loss fine structures in hexagonal GaN crystal are in good agreement with the experimental spectra. Future possible experiments in energy-filtered transmission electron microscopy (EFTEM) are discussed and proposed because our theoretical work can provide clear assignments for transmitted electrons with different energy losses.
基金Supported by National Natural Science Foundation of China (Grant No. 10771013)
文摘Denote by SFin(v) the set of all integer pairs (t, s) for which there exist three symmetric Latin squares of order v on the same set having fine structure (t, s). We completely determine the set SFin(2n) for any integer n ≥ 5.
文摘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.
文摘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.
文摘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.
文摘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.
基金supported by start-up funds from the laboratory of H.WFaculty Sponsored Student Research Awards(FSSRA)from the Department of Chemistry and Biochemistry in the College of Science and Mathematics at California State University,Fresno。
文摘In addition to the tens of millions of medical doses consumed annually around the world,a vast number of nuclear magnetic resonance imaging(MRI)contrast agents are being deployed in MRI research and development,offering precise diagnostic information,targeting capabilities,and analyte sensing.Superparamagnetic iron oxide nanoparticles(SPIONs)are notable among these agents,providing effective and versatile MRI applications while also being heavy-metal-free,bioconjugatable,and theranostic.We designed and implemented a novel two-pronged computational and experimental strategy to meet the demand for the efficient and rigorous development of SPION-based MRI agents.Our MATLAB-based modeling simulation and magnetic characterization revealed that extremely small maghemite SPIONs in the 1-3 nm range possess significantly reduced transversal relaxation rates(R_(2))and are therefore preferred for positive(T_(1)-weighted)MRI.Moreover,X-ray diffraction and X-ray absorption fine structure analyses demonstrated that the diffraction pattern and radial distribution function of our SPIONs matched those of the targeted maghemite crystals.In addition,simulations of the X-ray near-edge structure spectra indicated that our synthesized SPIONs,even at 1 nm,maintained a spherical structure.Furthermore,in vitro and in vivo MRI investigations showed that our 1-nm SPIONs effectively highlighted whole-body blood vessels and major organs in mice and could be cleared through the kidney route to minimize potential post-imaging side effects.Overall,our innovative approach enabled a swift discovery of the desired SPION structure,followed by targeted synthesis,synchrotron radiation spectroscopic studies,and MRI evaluations.The efficient and rigorous development of our high-performance SPIONs can set the stage for a computational and experimental platform for the development of future MRI agents.
基金National Key Research and Development Program of China(2020YFA0405800)National Natural Science Foundation of China(12322515,U23A20121,12225508)+2 种基金Youth Innovation Promotion Association of CAS(2022457)National Postdoctoral Program for Innovative Talents(BX20230346)China Postdoctoral Science Foundation(2023M743365)。
文摘Due to their high electrical conductivity and layered structure,two dimensional MXene materials are re⁃garded as promising candidates for energy storage applications.However,the relatively low stability and specific ca⁃pacity of MXene materials limit their further utilization.In this study,these issues are addressed using a heterostruc⁃ture strategy via a one-step selenization method to form Mo_(₂)C@MoSe_(₂).Synchrotron radiation X-ray spectroscopic and high-resolution transmission electron microscopy(HRTEM)characterizations revealed the heterostructure consisting of in-situ grown MoSe_(2)on Mo_(2)C MXene.Electrochemical tests proved the heterojunction electrode’s superior rate perfor⁃mance of 289.06 mAh·g^(-1)at a high current density of 5 A·g^(-1)and long cycling stability of 550 mAh·g^(-1)after 900 cycles at 1 A·g^(-1).This work highlights the useful X-ray spectroscopic analysis to directly elucidate the heterojunction structure,providing an effective reference method for probing heterostructures.
基金Project supported by the Shandong Provincial Natural Science Foundation,China(Grant Nos.ZR2022MA025 and ZR2020MA077).
文摘The possible configurations of pyrrole absorbed on a Si(100)surface have been investigated by x-ray photoelectron spectroscopy(XPS)and near-edge x-ray absorption fine structure(NEXAFS)spectra.The C-1s XPS and NEXAFS spectra of these adsorption configurations have been calculated by using the density functional theory(DFT)method and fullcore hole(FCH)approximation to investigate the relationship between the adsorption configurations and the spectra.The result shows that the XPS and NEXAFS spectra are structurally dependent on the configurations of pyrrole absorbed on the Si(100)surface.Compared with the XPS,the NEXAFS spectra are relatively sensitive to the adsorption configurations and can accurately identify them.The NEXAFS decomposition spectra produced by non-equivalent carbon atoms have also been calculated and show that the spectral features vary with the diverse types of carbon atoms and their structural environments.
文摘The Fine Structure Constant (eFSC) Model attempts to give a classical definition to a magical number that underlies much of quantum physics. The Fine Structure Constant (α) value equal to 137.03599206 represents a dimensionless constant that characterizes the strength of the electromagnetic (EM) interaction between subatomic charged particles. Python-generated property counts for the twin prime force F{139/137} show that the adjusted ratio gives a value of α = 137.036. This implies a mathematical framework underlying this constant is based on twin prime numbers and set theory. This study attempts to demonstrate a proof of concept that a hierarchy of fractional twin prime (αII) forces replicates the quantum nature of the universe and is aligned with the Standard Model of Particle Physics. An expanded eFSC Model demonstrates that twin prime forces and their property sets are mathematically viable substitutes for nuclear reactions, as demonstrated for the Beta-minus decay of neutrons into protons. Most significantly, the positive and negative prime numbers define these nuclear reactants and products as positive or negatively charged ions. Furthermore, the eFSC Model provides new insights regarding the hierarchy of EM forces underlying the quantum nature of the universe.
文摘This study aims to demonstrate a proof of concept for a novel theory of the universe based on the Fine Structure Constant (α), derived from n-dimensional prime number property sets, specifically α = 137 and α = 139. The FSC Model introduces a new perspective on the fundamental nature of our universe, showing that α = 137.036 can be calculated from these prime property sets. The Fine Structure Constant, a cornerstone in Quantum Electrodynamics (QED) and Quantum Chromodynamics (QCD), implies an underlying structure. This study identifies this mathematical framework and demonstrates how the FSC model theory aligns with our current understanding of physics and cosmology. The results unveil a hierarchy of α values for twin prime pairs U{3/2} through U{199/197}. These values, represented by their fraction parts α♊ (e.g., 0.036), define the relative electromagnetic forces driving quantum energy systems. The lower twin prime pairs, such as U{3/2}, exhibit higher EM forces that decrease as the twin pairs increase, turning dark when they drop below the α♊ for light. The results provide classical definitions for Baryonic Matter/Energy, Dark Matter, Dark Energy, and Antimatter but mostly illustrate how the combined α♊ values for three adjacent twin primes, U{7/5/3/2} mirrors the strong nuclear force of gluons holding quarks together.
文摘Previously, we presented several empirical equations using the cosmic microwave background (CMB) temperature. Next, we propose an empirical equation for the fine-structure constant. Considering the compatibility among these empirical equations, the CMB temperature (Tc) and gravitational constant (G) were calculated to be 2.726312 K and 6.673778 × 10−11 m3∙kg−1∙s−2, respectively. Every equation can be explained numerically in terms of the Compton length of an electron (λe), the Compton length of a proton (λp) and α. Furthermore, every equation can also be explained in terms of the Avogadro number and the number of electrons at 1 C. We show that every equation can be described in terms of the Planck constant. Then, the ratio of the gravitational force to the electric force can be uniquely determined with the assumption of minimum mass. In this report, we describe the algorithms used to explain these equations in detail. Thus, there are no dimension mismatch problems.
基金supported by the National Natural Science Foundation of China (10872096)the Open Fund of State Key Laboratory of Explosion Science and Technology,Beijing Institute of Technology (KFJJ09-13)
文摘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.
文摘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.