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Cortico-striatal gamma oscillations are modulated by dopamine D3 receptors in dyskinetic rats
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作者 Pengfei Wang Yuewei Bi +6 位作者 Min Li Jiazhi Chen Zhuyong Wang Huantao Wen Ming Zhou Minjie Luo Wangming Zhang 《Neural Regeneration Research》 SCIE CAS 2025年第4期1164-1177,共14页
Long-term levodopa administration can lead to the development of levodopa-induced dyskinesia.Gamma oscillations are a widely recognized hallmark of abnormal neural electrical activity in levodopa-induced dyskinesia.Cu... Long-term levodopa administration can lead to the development of levodopa-induced dyskinesia.Gamma oscillations are a widely recognized hallmark of abnormal neural electrical activity in levodopa-induced dyskinesia.Currently,studies have reported increased oscillation power in cases of levodopa-induced dyskinesia.However,little is known about how the other electrophysiological parameters of gamma oscillations are altered in levodopa-induced dyskinesia.Furthermore,the role of the dopamine D3 receptor,which is implicated in levodopa-induced dyskinesia,in movement disorder-related changes in neural oscillations is unclear.We found that the cortico-striatal functional connectivity of beta oscillations was enhanced in a model of Parkinson’s disease.Furthermore,levodopa application enhanced cortical gamma oscillations in cortico-striatal projections and cortical gamma aperiodic components,as well as bidirectional primary motor cortex(M1)↔dorsolateral striatum gamma flow.Administration of PD128907(a selective dopamine D3 receptor agonist)induced dyskinesia and excessive gamma oscillations with a bidirectional M1↔dorsolateral striatum flow.However,administration of PG01037(a selective dopamine D3 receptor antagonist)attenuated dyskinesia,suppressed gamma oscillations and cortical gamma aperiodic components,and decreased gamma causality in the M1→dorsolateral striatum direction.These findings suggest that the dopamine D3 receptor plays a role in dyskinesia-related oscillatory activity,and that it has potential as a therapeutic target for levodopa-induced dyskinesia. 展开更多
关键词 aperiodic components dopamine D3 receptor dorsolateral striatum functional connectivity gamma oscillations levodopa-induced-dyskinesia local field potentials NEUROMODULATION Parkinson’s disease primary motor cortex
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A study of the relation between intensity oscillations and magnetic field parameters in a sunspot: Hinode observations 被引量:1
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作者 A.Raja Bayanna Shibu K.Mathew +2 位作者 Brajesh Kumar Rohan E.Louis P.Venkatakrishnan 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2014年第11期1458-1468,共11页
We present properties of intensity oscillations of a sunspot in the photo- sphere and chromosphere using G band and Ca u H filtergrams from Hinode. Intensity power maps as function of magnetic field strength and frequ... We present properties of intensity oscillations of a sunspot in the photo- sphere and chromosphere using G band and Ca u H filtergrams from Hinode. Intensity power maps as function of magnetic field strength and frequency reveal reduction of power in the G band with an increase in photospheric magnetic field strength at all frequencies. In Ca II H, however, stronger fields exhibit more power at high frequen- cies, particularly in the 4.5-8.0 mHz band. Power distributions in different locations of the active region show that the oscillations in Ca II H exhibit more power compared to that of the G band. We also relate the power in intensity oscillations with differ- ent components of the photospheric vector magnetic field using near simultaneous spectro-polarimetric observations of the sunspot from the Hinode spectropolarime- ter. The photospheric umbral power is strongly anti-correlated with the magnetic field strength and its line-of-sight component but there is a good correlation with the trans- verse component. A reversal of this trend is observed in the chromosphere except at low frequencies (V≤ 1.5 mHz). The power in sunspot penumbrae is anti-correlated with the magnetic field parameters at all frequencies (1.0 ≤ v ≤ 8.0 mHz) in both the photosphere and chromosphere, except that the chromospheric power shows a strong correlation in the frequency range 3-3.5 mHz. 展开更多
关键词 sun photosphere -- sun chromosphere -- sun oscillations -- sun magnetic fields -- sun Hinode
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Local sunspot oscillations and umbral dots 被引量:1
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作者 Yuzef Zhugzhda Robert Sych 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2018年第9期1-12,共12页
Data analysis of sunspot oscillations based on a 6-hr SDO run of an observation showed that low frequency (0.2 〈ω 〈 1 mHz) oscillations are locally similar to three and five minute oscillations. The oscillations ... Data analysis of sunspot oscillations based on a 6-hr SDO run of an observation showed that low frequency (0.2 〈ω 〈 1 mHz) oscillations are locally similar to three and five minute oscillations. The oscillations in the sunspot are concentrated in cells of a few arcsec, each of which has its own oscillation spectrum. The analysis of two scenarios for sunspot oscillations leads to a conclusion that local sunspot oscillations occur due to a subphotospheric resonator for slow MHD waves. Empirical models of a sunspot atmosphere and the theory of slow waves in thin magnetic flux tubes are applied to modeling the subphotospheric resonator. The spectrum of local oscillations consists of a great number of lines. This kind of spectrum can occur only if the subphotospheric resonator is a magnetic tube with a rather weak magnetic field. Magnetic tubes of this sort are umbral dots that appear due to the convective tongues in monolithic sunspots. The interrelation of local oscillations with umbral dots and wavefronts of traveling waves in sunspots is discussed. 展开更多
关键词 sun sunspot - methods numerical - waves
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Chromospheric Internetwork Oscillations at Various Locations of the Quiet Sun 被引量:1
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作者 Zong-JunNing Ming-DeDing 《Chinese Journal of Astronomy and Astrophysics》 CSCD 2005年第3期273-284,共12页
We analyze oscillation behaviours in chromospheric internetwork regions using spectral observations of the C<SUB>II</SUB> 1334 ? line obtained with the Solar Ultraviolet Measurements of Emitted Radiation s... We analyze oscillation behaviours in chromospheric internetwork regions using spectral observations of the C<SUB>II</SUB> 1334 ? line obtained with the Solar Ultraviolet Measurements of Emitted Radiation spectrograph (SUMER) aboard Solar and Heliospheric Observatory (SOHO). Three areas, 26&#x00d7;120arcsec<SUP>2</SUP> each, at the various latitudes from the disk center to the north polar coronal hole, were rastered with a cadence of about 40–60 s in the solar minimum year. We obtained the time evolution of two-dimensional (2D) line intensity, continuum and line core shift. The continuum and the line shift show ~3 min chromospheric oscillations in the internetwork regions underlying the coronal hole as well as at the disk center. We find that the C<SUB>II</SUB> 1334 ? line shift oscillates with an average speed of ~1.7km<SUP>-1</SUP>, independent of the latitude, while its coherent scale decreases with latitude. On the other hand, the oscillation amplitude of the continuum around the 1334 ? and the phase delay between the Doppler shift and continuum slightly increase with latitude. 展开更多
关键词 CHROMOSPHERE oscillations
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Inter-correlation between Sunspot Oscillations and Their Internal Structures
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作者 Libo Fu Zizhan Zhu +3 位作者 Ding Yuan Jiaoyang Wang Song Feng Sergey Anfinogentov 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2022年第11期97-106,共10页
Three-and five-minute oscillations are commonly observed in any sunspot.Because they are modulated by the internal thermal and magnetic structures of a sunspot,they could be used as an effective tool for researching s... Three-and five-minute oscillations are commonly observed in any sunspot.Because they are modulated by the internal thermal and magnetic structures of a sunspot,they could be used as an effective tool for researching sunspot seismology.In this paper,we investigate the properties of oscillations in sunspot groups with varying sizes and magnetic fields,and aim to establish the relationships between sunspot oscillations and its internal structure comparatively.We selected three groups of the unipolar sunspot with approximately axial-symmetric magnetic field and calculated their Fourier spectra based on the ultraviolet/extreme ultraviolet emission intensity variations recorded by the Solar Dynamics Observatory/Atmospheric Imaging Assembly.We found that the distribution of three-minute oscillation is defined by the joint effect of diverging magnetic field and the stratification of the sunspot atmosphere.Its distribution could be modified by any invading magnetic structures in the umbra.In contrast,the five-minute oscillations are more prominent in small spots,implying that five-minute oscillation is very closely connected with umbral dynamics. 展开更多
关键词 (sun:)sunspots sun:oscillations methods:data analysis
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Django框架下的Sun求职平台构建与功能实现
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作者 梁孟晗 彭漠 +1 位作者 刘亚楠 于歌 《信息与电脑》 2024年第8期104-106,共3页
本文基于Django框架,设计与实现了Sun求职平台,旨在为求职者和招聘方提供一个高效、便捷的互联网招聘平台。通过采用Django的模型-视图-控制器(Model-View-Controller)架构,实现了用户注册、登录、简历上传、职位发布等核心功能。在前... 本文基于Django框架,设计与实现了Sun求职平台,旨在为求职者和招聘方提供一个高效、便捷的互联网招聘平台。通过采用Django的模型-视图-控制器(Model-View-Controller)架构,实现了用户注册、登录、简历上传、职位发布等核心功能。在前端方面,采用了Bootstrap框架进行页面布局,使界面简洁美观且具有响应性。在后端方面,利用Django的ORM系统实现了数据库的管理和交互,确保了系统的稳定性和安全性。通过整合第三方认证系统,提高了用户体验的同时,保障了信息的真实性。最终,Sun求职平台通过完善的功能和友好的界面,为求职者和企业搭建了一个高效的沟通桥梁,促进了人才与岗位的精准匹配。 展开更多
关键词 DJANGO 互联网招聘 sun求职平台 ORM系统
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Sunspot Group Detection and Classification by Dual Stream Convolutional Neural Network Method
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作者 Nyasha Mariam Mkwanda Weixin Tian Junlin Li 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2024年第9期248-259,共12页
The automatic detection and analysis of sunspots play a crucial role in understanding solar dynamics and predicting space weather events.This paper proposes a novel method for sunspot group detection and classificatio... The automatic detection and analysis of sunspots play a crucial role in understanding solar dynamics and predicting space weather events.This paper proposes a novel method for sunspot group detection and classification called the dual stream Convolutional Neural Network with Attention Mechanism(DSCNN-AM).The network consists of two parallel streams each processing different input data allowing for joint processing of spatial and temporal information while classifying sunspots.It takes in the white light images as well as the corresponding magnetic images that reveal both the optical and magnetic features of sunspots.The extracted features are then fused and processed by fully connected layers to perform detection and classification.The attention mechanism is further integrated to address the“edge dimming”problem which improves the model’s ability to handle sunspots near the edge of the solar disk.The network is trained and tested on the SOLAR-STORM1 data set.The results demonstrate that the DSCNN-AM achieves superior performance compared to existing methods,with a total accuracy exceeding 90%. 展开更多
关键词 sun:magnetic fields sun:flares (sun:)sunspots DSCNN Attention mechanism Edge dimming
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The Influence of the Sun and Moon on the Observation of Very High Energy Gamma-ray Sources Using EAS Arrays
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作者 Tao Wen Songzhan Chen Benzhong Dai 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2024年第6期245-252,共8页
With great advance of ground-based extensive air shower arrays,such as LHAASO and HAWC,many very high energy(VHE)gamma-ray sources have been discovered and are being monitored regardless of the day and the night.Hence... With great advance of ground-based extensive air shower arrays,such as LHAASO and HAWC,many very high energy(VHE)gamma-ray sources have been discovered and are being monitored regardless of the day and the night.Hence,the Sun and Moon would have some impacts on the observation of gamma-ray sources,which have not been taken into account in previous analysis.In this paper,the influence of the Sun and Moon on the observation of very high energy gamma-ray sources when they are near the line of sight of the Sun or Moon is estimated.The tracks of all the known VHE sources are scanned and several VHE sources are found to be very close to the line of sight of the Sun or Moon during some period.The absorption of very high energy gamma rays by sunlight is estimated with detailed method and some useful conclusions are achieved.The main influence is the block of the Sun and Moon on gamma rays and the shadow on the cosmic ray background.The influence is investigated considering the detector angular resolution and some strategies on data analysis are proposed to avoid the underestimation of the gamma-ray emission. 展开更多
关键词 astroparticle physics sun:general methods:observational sun:UV radiation
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Nonlinear Violence in Nonlinear Oscillations at High Energy
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作者 Yair Zarmi 《Applied Mathematics》 2024年第1期65-95,共31页
This paper focuses on the characteristics of solutions of nonlinear oscillatory systems in the limit of very high oscillation energy, E;specifically, systems, in which the nonlinear driving force grows with energy muc... This paper focuses on the characteristics of solutions of nonlinear oscillatory systems in the limit of very high oscillation energy, E;specifically, systems, in which the nonlinear driving force grows with energy much faster for x(t) close to the turning point, a(E), than at any position, x(t), that is not too close to a(E). This behavior dominates important aspects of the solutions. It will be called “nonlinear violence”. In the vicinity of a turning point, the solution of a nonlinear oscillatory systems that is affected by nonlinear violence exhibits the characteristics of boundary-layer behavior (independently of whether the equation of motion of the system can or cannot be cast in the traditional form of a boundary-layer problem.): close to a(E), x(t) varies very rapidly over a short time interval (which vanishes for E → ∞). In traditional boundary layer systems this would be called the “inner” solution. Outside this interval, x(t) soon evolves into a moderate profile (e.g. linear in time, or constant)—the “outer” solution. In (1 + 1)-dimensional nonlinear energy-conserving oscillators, if the solution is reflection-invariant, nonlinear violence determines the characteristics of the whole solution. For large families of nonlinear oscillatory systems, as E → ∞, the solutions for x(t) tend to common, indistinguishable profiles, such as periodic saw-tooth profiles or step-functions. If such profiles are observed experimentally in high-energy oscillations, it may be difficult to decipher the dynamical equations that govern the motion. The solution of motion in a central field with a non-zero angular momentum exhibits extremely fast rotation around a turning point that is affected by nonlinear violence. This provides an example for the possibility of interesting phenomena in (1 + 2)-dimensional oscillatory systems. 展开更多
关键词 High-Energy oscillations Nonlinear Violence Boundary-Layer Characteristics
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Solving the Olbers’s Paradox, Explaining the “Red-Shift”, and Challenging the Relativities by “Sun Matters Theory” and “Sun Model of Universe”, an Evolution of the Einstein’s Static Universe Model
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作者 Wanpeng Sun 《Natural Science》 2024年第2期7-18,共12页
Olbers’s paradox, known as the dark night paradox, is an argument in astrophysics that the darkness of the night sky conflicts with the assumption of an infinite and eternal static universe. Big-Bang theory was used ... Olbers’s paradox, known as the dark night paradox, is an argument in astrophysics that the darkness of the night sky conflicts with the assumption of an infinite and eternal static universe. Big-Bang theory was used to partially explain this paradox, while introducing new problems. Hereby, we propose a better theory, named Sun Matters Theory, to explain this paradox. Moreover, this unique theory supports and extended the Einstein’s static universe model proposed by Albert Einstein in 1917. Further, we proposed our new universe model, “Sun Model of Universe”. Based on the new model and novel theory, we generated innovative field equation by upgrading Einstein’s Field Equation through adding back the cosmological constant, introducing a new variable and modifying the gravitationally-related concepts. According to the Sun Model of Universe, the dark matter and dark energy comprise the so-called “Sun Matters”. The observed phenomenon like the red shift is explained as due to the interaction of ordinary light with Sun Matters leading to its energy and frequency decrease. In Sun Model, our big universe consists of many universes with ordinary matter at the core mixed and surrounded with the Sun Matters. In those universes, the laws of physics may be completely or partially different from that of our ordinary universe with parallel civilizations. The darkness of night can be easily explained as resulting from the interaction of light with the Sun Matters leading to the sharp decrease in the light intensity. Sun Matters also scatter the light from a star, which makes it shining as observed by Hubble. Further, there is a kind of Sun Matters named “Sun Waters”, surrounding every starts. When lights pass by the sun, the Sun Waters deflect the lights to bend the light path. According to the Sun Model, it is the light bent not the space bent that was proposed in the theory of relativities. 展开更多
关键词 Olbers’s Paradox sun Matters Theory sun Model of Universe Einstein’s Universe Dark Mass
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Necessary and Sufficient Conditions for Oscillations of the Generalized Liénard Systems
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作者 Hongtao Zhang Xiaolin Liu Ping Yan 《Applied Mathematics》 2024年第6期391-405,共15页
In this paper, we study the second-order nonlinear differential systems of Liénard-type x˙=1a(x)[ h(y)−F(x) ], y˙=−a(x)g(x). Necessary and sufficient conditions to ensure that all nontrivial solutions are oscil... In this paper, we study the second-order nonlinear differential systems of Liénard-type x˙=1a(x)[ h(y)−F(x) ], y˙=−a(x)g(x). Necessary and sufficient conditions to ensure that all nontrivial solutions are oscillatory are established by using a new nonlinear integral inequality. Our results substantially extend and improve previous results known in the literature. 展开更多
关键词 Generalized Liénard System Nonlinear Integral Inequality OSCILLATION
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The de Haas-van Alphen quantum oscillations in the kagome metal RbTi_(3)Bi_(5)
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作者 Zixian Dong Lei Shi +7 位作者 Bin Wang Mengwu Huo Xing Huang Chaoxin Huang Peiyue Ma Yunwei Zhang Bing Shen Meng Wang 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第10期356-361,共6页
The kagome system has attracted great interest in condensed matter physics due to its unique structure that canhost various exotic states such as superconductivity(SC),charge density waves(CDWs)and nontrivial topologi... The kagome system has attracted great interest in condensed matter physics due to its unique structure that canhost various exotic states such as superconductivity(SC),charge density waves(CDWs)and nontrivial topological states.The topological semimetal RbTi_(3)Bi_(5)consisting of a Ti kagome layer shares a similar crystal structure to the topologicalcorrelated materials AV_(3)Sb_(5)(A=K,Rb,Cs)but without the absence of CDW and SC.Systematic de Haas-van Alphenoscillation measurements are performed on single crystals of RbTi_(3)Bi_(5)to pursue nontrivial topological physics and exoticstates.Combining this with theoretical calculations,the detailed Fermi surface topology and band structure are investigated.A two-dimensional Fermi pocket b is revealed with a light effective mass,consistent with the semimetal predictions.TheLandau fan diagram of RbTi_(3)Bi_(5)reveals a zero Berry phase for the b oscillation in contrast to that of CsTi_(3)Bi_(5).Theseresults suggest that kagome RbTi_(3)Bi_(5)is a good candidate for exploring nontrivial topological exotic states and topologicalcorrelated physics. 展开更多
关键词 OSCILLATION Fermi surface band structure
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Jovian Planet Influence on the Forcing of Sunspot Cycles
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作者 Fred J. Cadieu 《World Journal of Condensed Matter Physics》 CAS 2024年第1期1-9,共9页
The history of our solar system has been greatly influenced by the fact that there is a large gas giant planet, Jupiter that has a nearly circular orbit. This has allowed relics of the early solar system formation to ... The history of our solar system has been greatly influenced by the fact that there is a large gas giant planet, Jupiter that has a nearly circular orbit. This has allowed relics of the early solar system formation to still be observable today. Since Jupiter orbits the Sun with a period of approximately 12 years, it has always been thought that this could be connected to the nearly 11-year periodic peak in the number of sunspots observed. In this paper, the Sun and planets are considered to be moving about a center of mass point as the different planets orbit the Sun. This is the action of gravity that holds the solar system together. The center of mass for the Jupiter-Sun system actually lies outside the Sun. The four gas giant planets dominate such effects and the four gas giant Jovian planets can be projected together to determine an effective distance from the Sun’s center. Taken together these effects do seem to function as a sunspot forcing factor with a periodicity very close to 11 years. These predictions are made without consideration of any details of what is happening in the interior of the Sun. From these estimates, sunspot cycle 25 will be expected to peak in about September-October of 2025. Sunspot cycle 26 should peak in the year March of 2037. 展开更多
关键词 sun Cycles Solar System Formation JUPITER
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Variation in the Flaring Potential of Different Sunspot Groups During Different Phases of Solar Cycles 23 and 24
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作者 Abha Singh Anurag Chaudhari +1 位作者 Gyaneshwar Sharma A.K.Singh 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2024年第2期144-153,共10页
In this present study,we have analyzed different types of X-ray solar flares(C,M,and X classes)coming out from different classes of sunspot groups(SSGs).The data which we have taken under this study cover the duration... In this present study,we have analyzed different types of X-ray solar flares(C,M,and X classes)coming out from different classes of sunspot groups(SSGs).The data which we have taken under this study cover the duration of 24 yr from 1996 to 2019.During this,we observed a total of 15015 flares(8417 in SC-23 and 6598 in SC-24)emitted from a total of 33780 active regions(21746 in SC-23 and 12034 in SC-24)with sunspot only.We defined the flaring potential or flare-production potential as the ratio of the total number of flares produced from a particular type of SSG to the total number of the same-class SSGs observed on the solar surface.Here we studied yearly changes in the flaring potential of different McIntosh class groups of sunspots in different phases of SC-23 and 24.In addition,we investigated yearly variations in the potential of producing flares by different SSGs(A,B,C,D,E,F,and H)during different phases(ascending,maximum,descending,and minimum)of SC-23 and 24.These are our findings:(1)D,E,and F SSGs have the potential of producing flares≥8 times greater than A,B,C and H SSGs;(2)The larger and more complex D,E,and F SSGs produced nearly 80%of flares in SC-23 and 24;(3)The A,B,C and H SSGs,which are smaller and simpler,produced only 20%of flares in SC-23 and 24;(4)The biggest and most complex SSGs of F-class have flaring potential 1.996 and 3.443 per SSG in SC-23 and 24,respectively.(5)The potential for producing flares in each SSG is higher in SC-24 than in SC-23,although SC-24 is a weaker cycle than SC-23.(6)The alterations in the number of flares(C+M+X)show different time profiles than the alterations in sunspot numbers during SC-23 and 24,with several peaks.(7)The SSGs of C,D,E,and H-class have the highest flaring potential in the descending phase of both SC-23 and 24.(8)F-class SSGs have the highest flaring potential in the descending phase of SC-23 but also in the maximum phase of SC-24. 展开更多
关键词 (sun:)sunspots-sun flares-sun activity-sun magnetic fields-sun filaments-prominences
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Two-dimensional Sb net generated nontrivial topological states in SmAgSb_(2) probed by quantum oscillations
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作者 袁健 石贤彪 +7 位作者 杜红 李田 郗传英 王霞 夏威 王保田 钟瑞丹 郭艳峰 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第7期51-58,共8页
The REAgSb_(2)(RE = rare earth and Y) family has drawn considerable research interest because the two-dimensional Sb net in their crystal structures hosts topological fermions and hence rich topological properties. We... The REAgSb_(2)(RE = rare earth and Y) family has drawn considerable research interest because the two-dimensional Sb net in their crystal structures hosts topological fermions and hence rich topological properties. We report herein the magnetization and magnetotransport measurements of SmAgSb_(2) single crystal, which unveil very large magnetoresistance and high carrier mobility up to 6.2 × 10^(3)% and 5.58 × 10^(3)cm^(2)·V^(-1)·s^(-1), respectively. The analysis of both Shubnikov–de Haas and de Haas–van Alphen quantum oscillations indicates nontrivial Berry phases in the paramagnetic state while trivial Berry curvature in the antiferromagnetic state, indicating a topological phase transition induced by the antiferromagnetic order. It is also supported by the first-principles calculations. The results not only provide a new interesting topological material but also offer valuable insights into the correlation between magnetism and nontrivial topological states. 展开更多
关键词 large magnetoresistance quantum oscillations topological phase transition
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Review of the Analysis and Suppression for High-frequency Oscillations of the Grid-connected Wind Power Generation System
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作者 Bo Pang Qi Si +4 位作者 Pan Jiang Kai Liao Xiaojuan Zhu Jianwei Yang Zhengyou He 《CES Transactions on Electrical Machines and Systems》 EI CSCD 2024年第2期127-142,共16页
High-frequency oscillation(HFO)of gridconnected wind power generation systems(WPGS)is one of the most critical issues in recent years that threaten the safe access of WPGS to the grid.Ensuring the WPGS can damp HFO is... High-frequency oscillation(HFO)of gridconnected wind power generation systems(WPGS)is one of the most critical issues in recent years that threaten the safe access of WPGS to the grid.Ensuring the WPGS can damp HFO is becoming more and more vital for the development of wind power.The HFO phenomenon of wind turbines under different scenarios usually has different mechanisms.Hence,engineers need to acquire the working mechanisms of the different HFO damping technologies and select the appropriate one to ensure the effective implementation of oscillation damping in practical engineering.This paper introduces the general assumptions of WPGS when analyzing HFO,systematically summarizes the reasons for the occurrence of HFO in different scenarios,deeply analyses the key points and difficulties of HFO damping under different scenarios,and then compares the technical performances of various types of HFO suppression methods to provide adequate references for engineers in the application of technology.Finally,this paper discusses possible future research difficulties in the problem of HFO,as well as the possible future trends in the demand for HFO damping. 展开更多
关键词 Damping method High-frequency oscillation STABILITY Wind power generation
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New Insight to the Surface Temperature of the Sun
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作者 Ryszard Petela 《Energy and Power Engineering》 2024年第8期285-292,共8页
Information is given on thermal radiation from the Sun, considered in practical engineering calculations of heat exchange. It was found that although the surface temperature of the Sun is assumed to be about 5800 K, t... Information is given on thermal radiation from the Sun, considered in practical engineering calculations of heat exchange. It was found that although the surface temperature of the Sun is assumed to be about 5800 K, the solar spectrum data measured by Kondratyev lead to a value of at least 7134 K. Such a higher value can be obtained by interpreting the Planck formula for the black radiation spectrum for the Kondratyev data. In addition, using the Stefan-Boltzmann law, the energetic emissivity of the Sun’s surface was determined to be 0.431. Furthermore, based on Petela’s formulae for exergy of thermal radiation, the exergetic emissivity of the Sun’s surface was also calculated at the level of 0.426. 展开更多
关键词 Thermal Radiation Radiation Temperature Surface Temperature Surface Emissivity sun Radiation Spectrum Plank Law Exergy of Radiation Photosphere
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Detection of Oscillations in Process Control Loops From Visual Image Space Using Deep Convolutional Networks
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作者 Tao Wang Qiming Chen +3 位作者 Xun Lang Lei Xie Peng Li Hongye Su 《IEEE/CAA Journal of Automatica Sinica》 SCIE EI CSCD 2024年第4期982-995,共14页
Oscillation detection has been a hot research topic in industries due to the high incidence of oscillation loops and their negative impact on plant profitability.Although numerous automatic detection techniques have b... Oscillation detection has been a hot research topic in industries due to the high incidence of oscillation loops and their negative impact on plant profitability.Although numerous automatic detection techniques have been proposed,most of them can only address part of the practical difficulties.An oscillation is heuristically defined as a visually apparent periodic variation.However,manual visual inspection is labor-intensive and prone to missed detection.Convolutional neural networks(CNNs),inspired by animal visual systems,have been raised with powerful feature extraction capabilities.In this work,an exploration of the typical CNN models for visual oscillation detection is performed.Specifically,we tested MobileNet-V1,ShuffleNet-V2,Efficient Net-B0,and GhostNet models,and found that such a visual framework is well-suited for oscillation detection.The feasibility and validity of this framework are verified utilizing extensive numerical and industrial cases.Compared with state-of-theart oscillation detectors,the suggested framework is more straightforward and more robust to noise and mean-nonstationarity.In addition,this framework generalizes well and is capable of handling features that are not present in the training data,such as multiple oscillations and outliers. 展开更多
关键词 Convolutional neural networks(CNNs) deep learning image processing oscillation detection process industries
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SunGas Renewables公司与C2X公司合作扩大北美绿色甲醇产能
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作者 程钰丹(译) 《石油炼制与化工》 CAS CSCD 北大核心 2024年第8期17-17,共1页
SunGas Renewables公司和C2X公司宣布建立战略合作伙伴关系,共同在北美开发和运营多个绿色甲醇生产设施,以增加可持续燃料的供应,并推进全球难减排行业的脱碳。SunGas Renewables公司是GTI Energy公司的分拆公司,是为可再生燃料生产提... SunGas Renewables公司和C2X公司宣布建立战略合作伙伴关系,共同在北美开发和运营多个绿色甲醇生产设施,以增加可持续燃料的供应,并推进全球难减排行业的脱碳。SunGas Renewables公司是GTI Energy公司的分拆公司,是为可再生燃料生产提供成熟工艺技术和设备的领导者。 展开更多
关键词 甲醇生产 可再生燃料 战略合作伙伴关系 sun 绿色
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Simulation and Performance Analysis of Six Types of Sun Tracker Approaches:A Comparative Analysis for Solar Concentrating Technology Application at Burkina Faso
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作者 Stanislas Sanfo Serge Dimitri Bazyomo +1 位作者 Tizane Daho Abdoulaye Ouedraogo 《Journal of Energy and Power Engineering》 CAS 2024年第1期1-8,共8页
Modelization equations of six approaches for tracking the sun are recalled and used to evaluate the constraints and performances to which they lead to.The geographical study case is taken for the specific latitude of ... Modelization equations of six approaches for tracking the sun are recalled and used to evaluate the constraints and performances to which they lead to.The geographical study case is taken for the specific latitude of 12 North that is a good matching with the location of the country of Burkina Faso.Three decisive periods were locally established in order to consider the different travels of the sun on sky during one year.This work presents some technical data which facilitates the choice of sun tracking approaches with concern of a concentrator limits such as its angle of acceptance,its motion control card interpolation model,or its minimum irradiation level for energy conversion effectiveness. 展开更多
关键词 Solar radiation sun tracker Burkina Faso experimental data
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