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Dyons of Unit Topological Charges in Gauged Skyrme Model
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作者 WU Zhong-lin LI Dong-ya 《Chinese Quarterly Journal of Mathematics》 2019年第2期152-170,共19页
Dyons are an important family of topological solitons carrying both electric and magnetic charges and the presence of a nontrivial temporal component of the gauge field essential for the existence of electricity often... Dyons are an important family of topological solitons carrying both electric and magnetic charges and the presence of a nontrivial temporal component of the gauge field essential for the existence of electricity often makes the analysis of the underlying nonlinear equations rather challenging since the governing action functional assumes an indefinite form.In this work,developing a constrained variational technique,We establish an existence theorem for the dyon solitons in a Skyrme model coupled with SO(3)-gauge fields,formulated by Brihaye,Kleihaus,and Tchrakian.These solutions carry unit monopole and Skyrme charges. 展开更多
关键词 SKYRME model GAUGE fields DYONS CALCULUS of variations for INDEFINITE action FUNCTIONALS weak convergence
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Heavy neutral leptons in gauged U(1)Lμ-Lτ at muon collider
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作者 Ru-Yi He Jia-Qi Huang +3 位作者 Jin-Yuan Xu Fa-Xin Yang Zhi-Long Han Feng-Lan Shao 《Chinese Physics C》 SCIE CAS CSCD 2024年第9期36-49,共14页
Heavy neutral leptons N are the most appealing candidates to generate tiny neutrino masses.We studied the signature of heavy neutral leptons in gauged U(1)Lμ-Lτ at a muon collider.Charged under the U(1)Lμ-Lτ symme... Heavy neutral leptons N are the most appealing candidates to generate tiny neutrino masses.We studied the signature of heavy neutral leptons in gauged U(1)Lμ-Lτ at a muon collider.Charged under the U(1)Lμ-Lτ symmetry,the heavy neutral leptons can be pair produced via the new gauge boson Z' at the muon collider as μ^(+)μ^(-)→Z′*→NN AND μ^(+)μ^(-)→Z′(*)γ→NNγ.We then performed a detailed analysis on the lepton number violation signature μ^(+)μ^(-)→NN→μ^(±)μ^(±)W■W■ and μ^(+)μ^(-)→NN→μ^(±)μ^(±)W■W■γ at the 3 TeV muon collider,where the hadronic decays of W boson are treated as fat-jets J.These lepton number violation signatures have quite clean backgrounds at the muon collider.Our simulation shows that a wide range of viable parameter space is within the reach of the 3 TeV muon collider.For instance,with new gauge coupling g'=0.6 and an integrated luminosity of 1000 fb^(-1),the μ^(±)μ^(±)JJ signal could probe m_(Z′)■13 TeV.Meanwhile,if the gauge boson mass satisfies 2m_(N)<√s,the μ^(±)μ^(±)JJγ signature would be more promising than the μ^(±)μ^(±)JJ signature. 展开更多
关键词 heavy neutral leptons gauged U(1)_(Lμ-Lτ) muon collider lepton number violation
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Correlation functions of gauged linear σ-model 被引量:2
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作者 TIAN Gang XU GuangBo 《Science China Mathematics》 SCIE CSCD 2016年第5期823-838,共16页
This is the second paper in a series following Tian and Xu(2015), on the construction of a mathematical theory of the gauged linear σ-model(GLSM). In this paper, assuming the existence of virtual moduli cycles and th... This is the second paper in a series following Tian and Xu(2015), on the construction of a mathematical theory of the gauged linear σ-model(GLSM). In this paper, assuming the existence of virtual moduli cycles and their certain properties, we define the correlation function of GLSM for a fixed smooth rigidified r-spin curve. 展开更多
关键词 gauged linear σ-model correlation function moduli space
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Monitoring absolute vertical land motions and absolute sea-level changes from GPS and tide gauges data over French Polynesia
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作者 Xianjie Li Jean-Pierre Barriot +2 位作者 Bernard Ducarme Marania Hopuare Yidong Lou 《Geodesy and Geodynamics》 EI CSCD 2024年第1期13-26,共14页
In this study,we estimate the absolute vertical land motions at three tidal stations with collocated Global Navigation Satellite System(GNSS)receivers over French Polynesia during the period 2007-2020,and obtain,as an... In this study,we estimate the absolute vertical land motions at three tidal stations with collocated Global Navigation Satellite System(GNSS)receivers over French Polynesia during the period 2007-2020,and obtain,as ancillary results,estimates of the absolute changes in sea level at the same locations.To verify our processing approach to determining vertical motion,we first modeled vertical motion at the International GNSS Service(IGS)THTI station located in the capital island of Tahiti and compared our estimate with previous independent determinations,with a good agreement.We obtained the following estimates for the vertical land motions at the tide gauges:Tubuai island,Austral Archipelago-0.92±0.17 mm/yr,Vairao village,Tahiti Iti:-0.49±0.39 mm/yr,Rikitea,Gambier Archipelago-0.43±0.17 mm/yr.The absolute variations of the sea level are:Tubuai island,Austral Archipelago 5.25±0.60 mm/yr,Vairao village,Tahiti Iti:3.62±0.52 mm/yr,Rikitea,Gambier Archipelago 1.52±0.23 mm/yr.We discuss these absolute values in light of the values obtained from altimetric measurements and other means in French Polynesia. 展开更多
关键词 GPS Tide gauges Sea level changes Vertical land motion
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Research on the strain gauge mounting scheme of track wheel force measurement system based on high-speed wheel/rail relationship test rig
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作者 Yuanwu Cai Bo Chen Chongyi Chang 《Railway Sciences》 2024年第4期503-513,共11页
Purpose-This paper aims to analyze the stress and strain distribution on the track wheel web surface and study the optimal strain gauge location for force measurement system of the track wheel.Design/methodology/appro... Purpose-This paper aims to analyze the stress and strain distribution on the track wheel web surface and study the optimal strain gauge location for force measurement system of the track wheel.Design/methodology/approach-Finite element method was employed to analyze the stress and strain distribution on the track wheel web surface under varying wheel-rail forces.Locations with minimal coupling interference between vertical and lateral forces were identified as suitable for strain gauge installation.Findings-The results show that due to the track wheel web’s unique curved shape and wheel-rail force loading mechanism,both tensile and compressive states exit on the surface of the web.When vertical force is applied,Mises stress and strain are relatively high near the inner radius of 710 mm and the outer radius of 1110mmof the web.Under lateral force,high Mises stress and strain are observed near the radius of 670mmon the inner and outer sides of the web.As the wheel-rail force application point shifts laterally toward the outer side,the Mises stress and strain near the inner radius of 710 mm of the web gradually decrease under vertical force while gradually increasing near the outer radius of 1110 mm of the web.Under lateral force,the Mises stress and strain on the surface of the web remain relatively unchanged regardless of the wheel-rail force application point.Based on the analysis of stress and strain on the surface of the web under different wheel-rail forces,the inner radius of 870 mm is recommended as the optimal mounting location of strain gauges for measuring vertical force,while the inner radius of 1143 mm is suitable for measuring lateral force.Originality/value-The research findings provide valuable insights for determining optimal strain gauge locations and designing an effective track wheel force measurement system. 展开更多
关键词 Track wheel High-speed wheel/rail relationship test rig Instrumented wheelset Strain gauge Finite element
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Unification of Gravitational and Strong Interaction Fields Using Partial Gauge Symmetry
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作者 Young Hwan Yun Kiho Jang 《Journal of High Energy Physics, Gravitation and Cosmology》 CAS 2024年第2期515-533,共19页
We propose the new field potential by maintaining both the symmetry of the scalar gauge and the conservation law keeping N?ether’s theorem, while disregarding the symmetry of the vector gauge. The new potential forms... We propose the new field potential by maintaining both the symmetry of the scalar gauge and the conservation law keeping N?ether’s theorem, while disregarding the symmetry of the vector gauge. The new potential forms like the well-type potential where a particle behaves almost freely but is very hard to escape without external energy, which can be interpreted as local confinement and asymptotic freedom. By assuming a 2-dimensional metric tensor in 4-dimensional space-time, we suggest the existence of 3 kinds of particles that resemble QCD with 3 color charges. We also show that the mass term exists but comes to zero and derive the charge and spin values. We can regard the particle with this new potential as a gluon, and the interaction in this well-type potential as a strong interaction for the properties of mass, charge, spin, and its behavior. We suggest the eight-fold way with this new particle, which is similar to the existing method based on SU (3) symmetry. Even though the strong interaction has been analyzed in the standard model and string theory, we build a new consistent model based on the theory of relativity including Riemann geometry, and show the unification of gravitational and strong interactional field. 展开更多
关键词 Strong Interaction Gauge Symmetry RELATIVITY QCD CONFINEMENT Asymptotic Freedom
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Economic Upturn Boosts Confidence
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作者 Zhang Hui 《China Today》 2024年第1期2-2,共1页
As the eventful year of 2023 drew to a close,China’s decisive economic rebound over the preceding 11 months continued to propel steady recovery of the flagging global economy.Last November,China’s retail sales of co... As the eventful year of 2023 drew to a close,China’s decisive economic rebound over the preceding 11 months continued to propel steady recovery of the flagging global economy.Last November,China’s retail sales of consumer goods-a major gauge of consumption strength-maintained accelerated growth,evident in a registered year-on-year increase of 10.1 percent,according to National Bureau of Statistics(NBS)data published on December 15.During the January-November period,moreover,total retail sales of the country’s consumer goods swelled to RMB 42.79 trillion-a 7.2 percent increase over the previous year. 展开更多
关键词 maintained continued GAUGE
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A model with flavor-dependent gauged U(1)B-L1×U(1)B-L2-L3 symmetry
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作者 Linping Mu niroshi Okada Chao-Qiang Gen 《Chinese Physics C》 SCIE CAS CSCD 2018年第12期44-52,共9页
We propose a new model with flavor-dependent gauged U(1)B-L1×U(1)B-L2-L3symmetry in addition to the flavor-blind symmetry in the Standard Model. The model contains three right-handed neutrinos to cancel gauge ano... We propose a new model with flavor-dependent gauged U(1)B-L1×U(1)B-L2-L3symmetry in addition to the flavor-blind symmetry in the Standard Model. The model contains three right-handed neutrinos to cancel gauge anomalies and several Higgs bosons to construct the measured fermion masses. We show the generic features of the model and explore its phenomenology. In particular, we discuss the current bounds on the extra gauge bosons from the K and B meson mixings as well as the LEP and LHC data, and focus on their contributions to the lepton flavor violating processes of ?i+1→?iγ(i=1,2). 展开更多
关键词 flavor-dependent gauged Abelian symmetries model building numerical analysis of gauge boson masses and coupling
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Observation about the Classical Electromagnetic Gauge Transformation and Its Quantum Correspondence
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作者 Gustavo V. López Jorge A. Lizarraga 《Journal of Modern Physics》 2024年第4期474-479,共6页
Using the Landau and symmetric gauges for the vector potential of a constant magnetic field and the quantum problem of a charged particle moving on a flat surface, we show the classical electromagnetic gauge transform... Using the Landau and symmetric gauges for the vector potential of a constant magnetic field and the quantum problem of a charged particle moving on a flat surface, we show the classical electromagnetic gauge transformation does not correspond to a one-dimensional unitary group transformation U(1) of the wave function for the quantum case. In addition, with the re-examination of the relation between the magnetic field B and its vector potential  A, we found that, in order to have a consistent formulation of the dynamics of the charged particle with both expressions, we must have that B=∇×A if and only if B≠0. 展开更多
关键词 Gauge Transformation Harmonic Oscillator Quantum Hall Effect Electromagnetic Potentials
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Ashtekar-Kodama Gravity as a Classical and Quantum Extension of Loop Quantum Gravity
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作者 Jan Helm 《Journal of Modern Physics》 2024年第6期864-937,共74页
This paper presents a new theory of gravity, called here Ashtekar-Kodama (AK) gravity, which is based on the Ashtekar-Kodama formulation of loop quantum gravity (LQG), yields in the limit the Einstein equations, and i... This paper presents a new theory of gravity, called here Ashtekar-Kodama (AK) gravity, which is based on the Ashtekar-Kodama formulation of loop quantum gravity (LQG), yields in the limit the Einstein equations, and in the quantum regime a full renormalizable quantum gauge field theory. The three fundamental constraints (hamiltonian, gaussian and diffeomorphism) were formulated in 3-dimensional spatial form within LQG in Ashtekar formulation using the notion of the Kodama state with positive cosmological constant Λ. We introduce a 4-dimensional covariant version of the 3-dimensional (spatial) hamiltonian, gaussian and diffeomorphism constraints of LQG. We obtain 32 partial differential equations for the 16 variables E<sub>mn</sub> (E-tensor, inverse densitized tetrad of the metric) and 16 variables A<sub>mn</sub> (A-tensor, gravitational wave tensor). We impose the boundary condition: for large distance the E-generated metric g(E) becomes the GR-metric g (normally Schwarzschild-spacetime). The theory based on these Ashtekar-Kodama (AK) equations, and called in the following Ashtekar-Kodama (AK-) gravity has the following properties. • For Λ = 0 the AK equations become Einstein equations, A-tensor is trivial (constant), and the E-generated metric g(E) is identical with the GR-metric g. • When the AK-equations are developed into a Λ-power series, the Λ-term yields a gravitational wave equation, which has only at least quadrupole wave solutions and becomes in the limit of large distance r the (normal electromagnetic) wave equation. • AK-gravity, as opposed to GR, has no singularity at the horizon: the singularity in the metric becomes a (very high) peak. • AK-gravity has a limit scale of the gravitational quantum region 39 μm, which emerges as the limit scale in the objective wave collapse theory of Gherardi-Rimini-Weber. In the quantum region, the AK-gravity becomes a quantum gauge theory (AK quantum gravity) with the Lie group extended SU(2) = ε-tensor-group(four generators) as gauge group and a corresponding covariant derivative. • AK quantum gravity is fully renormalizable, we derive its Lagrangian, which is dimensionally renormalizable, the normalized one-graviton wave function, the graviton propagator, and demonstrate the calculation of cross-section from Feynman diagrams. 展开更多
关键词 Quantum Gravity Loop Quantum Gravity General Relativity Gravitational Wave Gauge Field Theory Graviton Hamiltonian Constraint Gaussian Constraint Diffeomorphism Constraint
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Supersymmetric AdS_4 vacua in N=3 gauged supergravity
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作者 曹贞斌 《Chinese Physics C》 SCIE CAS CSCD 2018年第5期42-45,共4页
We study the maximally supersymmetric AdS backgrounds of matter-coupled N=3 gauged supergravity in four dimensions. We find that to admit supersymmetric AdS vacua, the gauge group can only be of the form G0×H?SO(... We study the maximally supersymmetric AdS backgrounds of matter-coupled N=3 gauged supergravity in four dimensions. We find that to admit supersymmetric AdS vacua, the gauge group can only be of the form G0×H?SO(3,n) with G0=SO(3),SO(3,1) or SL(3,R) and H a compact group of dimension n+3-dim(G0). We also show that these AdS vacua have no moduli, namely they correspond to critical points in field space. 展开更多
关键词 gauge supergravity AdS background MODULI
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B^0-B^0 Mixing in Local Gauged Baryon and Lepton Numbers
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作者 孙飞 冯太傅 +3 位作者 罗国慧 赵树民 孙科盛 寇丽娜 《Communications in Theoretical Physics》 SCIE CAS CSCD 2013年第12期721-726,共6页
Using the effective Hamiltonian method, we analyze the B0-B0 mixing in the extension of the standard model (SM) where baryon number and lepton number are local gauge symmetries. The numerical results indicate the co... Using the effective Hamiltonian method, we analyze the B0-B0 mixing in the extension of the standard model (SM) where baryon number and lepton number are local gauge symmetries. The numerical results indicate the correction from the extra particles to the mass difference ArnB is significant. There is a 60% enhancement compared to the SM prediction for AraB at most, which agrees with the current experimental result. 展开更多
关键词 B0-B0 mixing Baryon number local gauge symmetry effective Hamiltonian
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Oblique parameters in gauged baryon and lepton numbers with a 125 GeV Higgs
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作者 杨秀一 聂晶 《Chinese Physics C》 SCIE CAS CSCD 2014年第5期1-11,共11页
In an extension of the standard model, where baryon number and lepton number are local gauge sym- metries, we analyze the effect of corrections from exotic fermions and scalars on the oblique parameters S, T, U. Becau... In an extension of the standard model, where baryon number and lepton number are local gauge sym- metries, we analyze the effect of corrections from exotic fermions and scalars on the oblique parameters S, T, U. Because a light neutral Higgs h0 with mass around 12-126 GeV strongly constrains the corresponding parameter space of this model, we also investigate the gluon fusion process gg→h0 and two photon decay of the lightest neutral Higgs h0→yy at the Large Hadron Collider. 展开更多
关键词 local gauge symmetry baryon and lepton numbers HIGGS
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t→cγ and t→cg in Local Gauged Baryon and Lepton Numbers
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作者 高铁军 冯太傅 孙飞 《Communications in Theoretical Physics》 SCIE CAS CSCD 2014年第1期95-100,共6页
In this paper, we calculate the top quark rare decays t →cγ and v in an extension of the standard model, where baryon number and lepton number are local gauge symmetries. Adopting reasonable assumptions on the param... In this paper, we calculate the top quark rare decays t →cγ and v in an extension of the standard model, where baryon number and lepton number are local gauge symmetries. Adopting reasonable assumptions on the parameter space, we find that the branching ratios of t →cγ and t →cg can reach 10^-6 and 10^-5 respectively, which can be detected in near future. 展开更多
关键词 local gauge symmetry baryon and lepton numbers top quark decays
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Influence of band microstructure on carbide precipitation behavior and toughness of 1 GPa-grade ultra-heavy gauge low-alloy steel 被引量:5
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作者 Peng Han Zhipeng Liu +4 位作者 Zhenjia Xie Hua Wang Yaohui Jin Xuelin Wang Chengjia Shang 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2023年第7期1329-1337,共9页
This study investigated the influence of band microstructure induced by centerline segregation on carbide precipitation behavior and toughness in an 80 mm-thick 1 GPa low-carbon low-alloy steel plate.The quarter-thick... This study investigated the influence of band microstructure induced by centerline segregation on carbide precipitation behavior and toughness in an 80 mm-thick 1 GPa low-carbon low-alloy steel plate.The quarter-thickness(1/4t)and half-thickness(1/2t)regions of the plate exhibited similar ductility and toughness after quenching.After tempering,the 1/4t region exhibited~50%and~25%enhancements in both the total elongation and low-temperature toughness at-40°C,respectively,without a decrease in yield strength,whereas the toughness of the 1/2t region decreased by~46%.After quenching,both the 1/4t and 1/2t regions exhibited lower bainite and lath martensite concentrations,but only the 1/2t region exhibited microstructure bands.Moreover,the tempered 1/4t region featured uniformly dispersed short rod-like M_(23)C_(6)carbides,and spherical MC precipitates with diameters of~20–100 nm and<20 nm,respectively.The uniformly dispersed nanosized M_(23)C_(6)carbides and MC precipitates contributed to the balance of high strength and high toughness.The band microstructure of the tempered 1/2t region featured a high density of large needle-like M3C carbides.The length and width of the large M3C carbides were~200–500 nm and~20–50 nm,respectively.Fractography analysis revealed that the high density of large carbides led to delamination cleavage fracture,which significantly deteriorated toughness. 展开更多
关键词 band microstructure carbides TOUGHNESS heavy gauge steel centerline segregation
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Combination of Tsoft and ET34-ANA-V80 software for the preprocessing and analysis of tide gauge data in French Polynesia 被引量:1
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作者 Bernard Ducarme Jean-Pierre Barriot Fangzhao Zhang 《Geodesy and Geodynamics》 CSCD 2023年第1期26-34,共9页
Since 2008 a network of five sea-level monitoring stations was progressively installed in French Polynesia.The stations are autonomous and data,collected at a sampling rate of 1 or 2 min,are not only recorded locally,... Since 2008 a network of five sea-level monitoring stations was progressively installed in French Polynesia.The stations are autonomous and data,collected at a sampling rate of 1 or 2 min,are not only recorded locally,but also transferred in real time by a radio-link to the NOAA through the GOES satellite.The new ET34-ANA-V80 version of ETERNA,initially developed for Earth Tides analysis,is now able to analyze ocean tides records.Through a two-step validation scheme,we took advantage of the flexibility of this new version,operated in conjunction with the preprocessing facilities of the Tsoft software,to recover co rrected data series able to model sea-level variations after elimination of the ocean tides signal.We performed the tidal analysis of the tide gauge data with the highest possible selectivity(optimal wave grouping)and a maximum of additional terms(shallow water constituents).Our goal was to provide corrected data series and modelled ocean tides signal to compute tide-free sea-level variations as well as tidal prediction models with centimeter precision.We also present in this study the characteristics of the ocean tides in French Polynesia and preliminary results concerning the non-tidal variations of the sea level concerning the tide gauge setting. 展开更多
关键词 Tide gauges Tidal data processing Mean sea level
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Water Gauge Image Denoising Model Based on Improved Adaptive Total Variation 被引量:1
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作者 SHI Zhenting ZHOU Xianchun +2 位作者 ZHANG Ying LI Ting LU Siqi 《Instrumentation》 2023年第1期59-68,共10页
As an important part of water level warning in water conservancy projects,often due to the influence of environmental factors such as light and stains,the acquired water gauge images have sticky,broken and bright spot... As an important part of water level warning in water conservancy projects,often due to the influence of environmental factors such as light and stains,the acquired water gauge images have sticky,broken and bright spot conditions,which affect the identification of water gauges.To solve this problem,a water gauge image denoising model based on improved adaptive total variation is proposed.Firstly,the regular term exponent in the adaptive total variational equation is changed to an inverse cosine function;secondly,the differential curvature is used to distinguish the image noise points and increase the smoothing strength at the noise points;finally,according to the characteristics of the gradient mode and adaptive gradient threshold after Gaussian filtering,the New model can adaptively denoise in the smooth area and protect the edge area,so as to have the characteristics of both edge-preserving denoising.The experimental results show that the new model has a great improvement in image vision,higher iteration efficiency and an average increase of 1.6 dB in peak signal-to-noise ratio,and an average increase of 9%in structural similarity,which is more beneficial to practical applications. 展开更多
关键词 Water Gauge Image Adaptive Total Variation Differential Curvature Gradient Mode Adaptive Gradient Threshold
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Feasibility of maintaining satellite altimetry calibration site based on qianliyan islet at the Yellow Sea
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作者 Bin Guan Zhongmiao Sun +2 位作者 Lei Yang Zhenhe Zhai Jian Ma 《Geodesy and Geodynamics》 EI CSCD 2023年第3期223-230,共8页
The calibration of the sea surface height(SSH)measured by satellite altimeters is essential to understand altimeter biases.Many factors affects the construction and maintenance of a permanent calibration site.In order... The calibration of the sea surface height(SSH)measured by satellite altimeters is essential to understand altimeter biases.Many factors affects the construction and maintenance of a permanent calibration site.In order to calibrate Chinese satellite altimetry missions,the feasibility of maintaining a calibration site based on the Qianliyan islet in Yellow Sea of China is taken into account.The related calibration facilities,such as the permanent tide gauge,GNSS reference station and meteorological station,were already operated by the Ministry of Natural Resources of China.The data could be fully used for satellite altimeter calibration with small fiscal expenditure.In addition,the location and marine environments of Qianliyan were discussed.Finally,we used the Jason-3 mission to check the possibility of calibration works.The result indicates that the brightness temperatures of three channels measured by microwave radiometer(MWR)and the derived wet tropospheric correction varies smoothly,which means the land contamination to MWR could be ignored.The high frequency waveforms at the Qianliyan site present no obvious difference from the normal waveforms received by satellite radar altimeter over the open ocean.In conclusion,the Qianliyan islet will not influence satellite altimetry observation.Following these analyses,a possible layout and mechanism of the Qianliyan calibration site are proposed. 展开更多
关键词 Satellite altimetry Altimeter calibration Satellite radar altimeter Microwave radiometer JASON Tide gauge
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A new Ignition-Growth reaction rate model for shock initiation
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作者 Yang Yang Zhuo-ping Duan +4 位作者 Shu-rui Li Lian-sheng Zhang Feng-lei Huang Yong Han Hui Huang 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2023年第5期126-136,共11页
Accurately predicting reactive flow is a challenge when characterizing an explosive under external shock stimuli as the shock initiation time is on the order of a microsecond.The present study constructs a new Ignitio... Accurately predicting reactive flow is a challenge when characterizing an explosive under external shock stimuli as the shock initiation time is on the order of a microsecond.The present study constructs a new Ignition-Growth reaction rate model,which can describe the shock initiation processes of explosives with different initial densities,particle sizes and loading pressures by only one set of model parameters.Compared with the Lee-Tarver reaction rate model,the new Ignition-Growth reaction rate model describes better the shock initiation process of explosives and requires fewer model parameters.Moreover,the shock initiation of a 2,4-Dinitroanisole(DNAN)-based melt-cast explosive RDA-2(DNAN/HMX(octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazoncine)/aluminum)are investigated both experimentally and numerically.A series of shock initiation experiments is performed with manganin piezoresistive pressure gauges and corresponding numerical simulations are carried out with the new Ignition-Growth reaction rate model.The RDA-2 explosive is found to have higher critical initiation pressure and lower shock sensitivity than traditional explosives(such as the Comp.B explosive).The calibrated reaction rate model parameters of RDA-2 could provide numerical basis for its further application. 展开更多
关键词 Shock initiation Ignition-growth reaction rate model Manganin pressure gauge Insensitive explosive DNAN-Based melt-cast explosive
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Numerical Simulation and Experimental Study of the Stress Formation Mechanism of FDM with Different Printing Paths
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作者 Heping Hou Yang Yue +2 位作者 Jian Liu Darun Xi Shanhui Liu 《Journal of Renewable Materials》 SCIE EI 2023年第1期273-289,共17页
Environmental contamination has been caused by petroleum-based polymeric materials in the melt deposition process.Nowadays biodegradable materials have been widely used in the fused deposition modeling(FDM)industry,su... Environmental contamination has been caused by petroleum-based polymeric materials in the melt deposition process.Nowadays biodegradable materials have been widely used in the fused deposition modeling(FDM)industry,such as polylactic acid(PLA).However,internal complex thermal stress and deformations in part caused by an uneven distribution of PLA filament deposition temperatures during FDM,which will seriously affect the geometric accuracy of the printed part.In order to reduce material waste and environmental pollution during the printing process,the accuracy of PLA part can be improved.Herein,numerical simulation was carried out to investigate the temperature field and stress field during the building and cooling process of cuboid specimens.The effects of printing path on the thermal stress and temperature field during the building process were mainly studied.The results show that the printing path has a significant effect on the stress distribution.The most uni-form stress distribution and the smallest deformation were obtained using the Zig Zag printing path.Finally,the residual stress during the cooling process was collected using strain gauges embedded at the mid-plane of the FDM built cuboid specimens.The simulation results are consistent with the experimental results. 展开更多
关键词 Fused deposition molding numerical simulation strain gauges stress measurement
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