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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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Surface plasmon oscillations in a semi-bounded semiconductor plasma
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作者 M SHAHMANSOURI A P MISRA 《Plasma Science and Technology》 SCIE EI CAS CSCD 2018年第2期76-81,共6页
We study the dispersion properties of surface plasmon(SP) oscillations in a semi-bounded semiconductor plasma with the effects of the Coulomb exchange(CE) force associated with the spin polarization of electrons a... We study the dispersion properties of surface plasmon(SP) oscillations in a semi-bounded semiconductor plasma with the effects of the Coulomb exchange(CE) force associated with the spin polarization of electrons and holes as well as the effects of the Fermi degenerate pressure and the quantum Bohm potential.Starting from a quantum hydrodynamic model coupled to the Poisson equation,we derive the general dispersion relation for surface plasma waves.Previous results in this context are recovered.The dispersion properties of the surface waves are analyzed in some particular cases of interest and the relative influence of the quantum forces on these waves are also studied for a nano-sized Ga As semiconductor plasma.It is found that the CE effects significantly modify the behaviors of the SP waves.The present results are applicable to understand the propagation characteristics of surface waves in solid density plasmas. 展开更多
关键词 surface plasmon oscillations semiconductor plasma semi-bounded plasma
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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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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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MINIMIZERS OF L^(2)-SUBCRITICAL VARIATIONAL PROBLEMS WITH SPATIALLY DECAYING NONLINEARITIES IN BOUNDED DOMAINS
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作者 陈彬 高永帅 +1 位作者 郭玉劲 吴越 《Acta Mathematica Scientia》 SCIE CSCD 2024年第3期984-996,共13页
This paper is concerned with the minimizers of L^(2)-subcritical constraint variar tional problems with spatially decaying nonlinearities in a bounded domain Ω of R~N(N≥1).We prove that the problem admits minimizers... This paper is concerned with the minimizers of L^(2)-subcritical constraint variar tional problems with spatially decaying nonlinearities in a bounded domain Ω of R~N(N≥1).We prove that the problem admits minimizers for any M> 0.Moreover,the limiting behavior of minimizers as M→∞ is also analyzed rigorously. 展开更多
关键词 decaying nonlinearity L~2-subcritical MINIMIZERS bounded domains mass concentration
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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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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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Impact of a Bumpy Nonuniform Electric Field on Oscillations of a Massive Point-Like Charged Particle
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作者 Haiduke Sarafian 《American Journal of Computational Mathematics》 2024年第2期240-247,共8页
As a general feature, the electric field of a localized electric charge distribution diminishes as the distance from the distribution increases;there are exceptions to this feature. For instance, the electric field of... As a general feature, the electric field of a localized electric charge distribution diminishes as the distance from the distribution increases;there are exceptions to this feature. For instance, the electric field of a charged ring (being a localized charge distribution) along its symmetry axis perpendicular to the ring through its center rather than as expected being a diminishing field encounters a local maximum bump. It is the objective of this research-oriented study to analyze the impact of this bump on the characteristics of a massive point-like charged particle oscillating along the symmetry axis. Two scenarios with and without gravity along the symmetry axis are considered. In addition to standard kinematic diagrams, various phase diagrams conducive to a better understanding are constructed. Applying Computer Algebra System (CAS), [1] [2] most calculations are carried out symbolically. Finally, by assigning a set of reasonable numeric parameters to the symbolic quantities various 3D animations are crafted. All the CAS codes are included. 展开更多
关键词 Nonlinear oscillations Nonuniform Electric Field Computer Algebra System MATHEMATICA
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The Reality of Baryonic Acoustic Oscillations
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作者 J. C. Botke 《Journal of Modern Physics》 2024年第3期377-402,共26页
The initial idea for baryonic acoustic oscillations (BAO) came about during early efforts to understand the origin of galaxies by studying perturbed versions of the Friedmann-Robertson-Walker (FRW) model. In more rece... The initial idea for baryonic acoustic oscillations (BAO) came about during early efforts to understand the origin of galaxies by studying perturbed versions of the Friedmann-Robertson-Walker (FRW) model. In more recent times, the emphasis has shifted to the idea that 2-point galaxy correlations embedded in the distribution of matter by the BAO could be used as a standard ruler to fix the parameters of cosmological models. In this paper, we first consider the actual business of extracting the correlation length from large data sets of measured galaxy locations. To facilitate this process, we introduce a much-improved method for extracting the correlation peak from the data set. Fundamental to this process in any model is the use of a fiducial cosmological model to transition from redshift space to comoving coordinate space where the correlations actually exist. The belief is that the correlation length so determined can then be reverted to redshift space to fix the parameters of cosmological models. We show, however, that this process is circular and hence of no value whatsoever for fixing model parameters. All one obtains are the parameters of the model used to transition to comoving space in the first place. Finally, we present simple arguments that show that the idea of BAO being responsible for the structure of the universe, i.e. the cosmic web, is unworkable. 展开更多
关键词 Baryonic Acoustic oscillations Two-Point Correlations CMB Anisotropy Early Universe Time-Varying Curvature
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Derivation of a Revised Tsiolkovsky Rocket Equation That Predicts Combustion Oscillations
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作者 Zaki Harari 《Advances in Aerospace Science and Technology》 2024年第1期10-27,共18页
Our study identifies a subtle deviation from Newton’s third law in the derivation of the ideal rocket equation, also known as the Tsiolkovsky Rocket Equation (TRE). TRE can be derived using a 1D elastic collision mod... Our study identifies a subtle deviation from Newton’s third law in the derivation of the ideal rocket equation, also known as the Tsiolkovsky Rocket Equation (TRE). TRE can be derived using a 1D elastic collision model of the momentum exchange between the differential propellant mass element (dm) and the rocket final mass (m1), in which dm initially travels forward to collide with m1 and rebounds to exit through the exhaust nozzle with a velocity that is known as the effective exhaust velocity ve. We observe that such a model does not explain how dm was able to acquire its initial forward velocity without the support of a reactive mass traveling in the opposite direction. We show instead that the initial kinetic energy of dm is generated from dm itself by a process of self-combustion and expansion. In our ideal rocket with a single particle dm confined inside a hollow tube with one closed end, we show that the process of self-combustion and expansion of dm will result in a pair of differential particles each with a mass dm/2, and each traveling away from one another along the tube axis, from the center of combustion. These two identical particles represent the active and reactive sub-components of dm, co-generated in compliance with Newton’s third law of equal action and reaction. Building on this model, we derive a linear momentum ODE of the system, the solution of which yields what we call the Revised Tsiolkovsky Rocket Equation (RTRE). We show that RTRE has a mathematical form that is similar to TRE, with the exception of the effective exhaust velocity (ve) term. The ve term in TRE is replaced in RTRE by the average of two distinct exhaust velocities that we refer to as fast-jet, vx<sub>1</sub>, and slow-jet, vx<sub>2</sub>. These two velocities correspond, respectively, to the velocities of the detonation pressure wave that is vectored directly towards the exhaust nozzle, and the retonation wave that is initially vectored in the direction of rocket propagation, but subsequently becomes reflected from the thrust surface of the combustion chamber to exit through the exhaust nozzle with a time lag behind the detonation wave. The detonation-retonation phenomenon is supported by experimental evidence in the published literature. Finally, we use a convolution model to simulate the composite exhaust pressure wave, highlighting the frequency spectrum of the pressure perturbations that are generated by the mutual interference between the fast-jet and slow-jet components. Our analysis offers insights into the origin of combustion oscillations in rocket engines, with possible extensions beyond rocket engineering into other fields of combustion engineering. 展开更多
关键词 Tsiolkovsky Rocket Equation Ideal Rocket Equation Rocket Propulsion Newton’s Third Law Combustion oscillations Combustion Instability
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Evidence of Hydropassive Movement in Stomatal Oscillations of Glycyrrhiza inflata under Desert Conditions 被引量:8
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作者 王根轩 廖建雄 吴冬秀 《Acta Botanica Sinica》 CSCD 2001年第1期41-45,共5页
Stomatal conductance was found to change from steady-state to a slate of oscillations during daytime when vapour pressure deficit (VPD) increased to a value of 1 kPa in Glycyrrhiza inflata Batalin grown under the cond... Stomatal conductance was found to change from steady-state to a slate of oscillations during daytime when vapour pressure deficit (VPD) increased to a value of 1 kPa in Glycyrrhiza inflata Batalin grown under the conditions of arid desert in north-west China. The injected metabolic inhibitors (NaN3 or carbonyl cyanide-m-chlorophenyl-hydrazone (CCCP)) slightly reduced the stomatal conductance but did not significantly decrease the intensity of stomatal oscillations (amplitude/average). The oscillation intensity was found to he significantly correlated with VPD and root resistance, but not with the respiration rate. There might exist a minimum threshold of VPD (0.8 kPa) and root resistance (1/4 relative value) that induced stomatal oscillations. These results suggested that stomatal oscillations induced by atmospheric drought stress and root resistance were mainly a type of hydropassive movement. 展开更多
关键词 stomatal oscillations Glycyrrhiza inflata hydropassive movement stomatal conductance vapour pressure deficit
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Oscillations of the Solutions of Hyperbolic Partial Differential Equations of Neutral Type 被引量:4
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作者 刘安平 曹少琛 《Chinese Quarterly Journal of Mathematics》 CSCD 2002年第2期7-13,共7页
In this paper, oscillatory properties of solutions of certain nonlinear hyperbolic partial differential equations are investigated and a series of sufficient conditions for oscillations of the equations are establishe... In this paper, oscillatory properties of solutions of certain nonlinear hyperbolic partial differential equations are investigated and a series of sufficient conditions for oscillations of the equations are established. The results fully indicate that the oscillations are caused by delay. 展开更多
关键词 HYPERBOLIC DELAY OSCILLATION nonlinear NEUTRAL
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Completeness of bounded model checking temporal logic of knowledge
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作者 刘志锋 葛云 +1 位作者 章东 周从华 《Journal of Southeast University(English Edition)》 EI CAS 2010年第3期399-405,共7页
In order to find the completeness threshold which offers a practical method of making bounded model checking complete, the over-approximation for the complete threshold is presented. First, a linear logic of knowledge... In order to find the completeness threshold which offers a practical method of making bounded model checking complete, the over-approximation for the complete threshold is presented. First, a linear logic of knowledge is introduced into the past tense operator, and then a new temporal epistemic logic LTLKP is obtained, so that LTLKP can naturally and precisely describe the system's reliability. Secondly, a set of prior algorithms are designed to calculate the maximal reachable depth and the length of the longest of loop free paths in the structure based on the graph structure theory. Finally, some theorems are proposed to show how to approximate the complete threshold with the diameter and recurrence diameter. The proposed work resolves the completeness threshold problem so that the completeness of bounded model checking can be guaranteed. 展开更多
关键词 bounded model checking temporal logics of knowledge multi-agent system
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Study of thermal decoherence of harmonic oscillators
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作者 LI Jian ZHOU Gao-Liang +2 位作者 YAN Zheng-Xin LIU Wei WANG Zhao-Qi 《原子与分子物理学报》 CAS 北大核心 2025年第5期108-114,共7页
The thermal decoherence of harmonic oscillators is investigated here.The quantum system presented here is a one-dimensional oscillator with angular frequency,which is surrounded by a thermal bath of environmental osci... The thermal decoherence of harmonic oscillators is investigated here.The quantum system presented here is a one-dimensional oscillator with angular frequency,which is surrounded by a thermal bath of environmental oscillators.There are various environmental oscillators with different angular frequency(below an ultraviolet cutoff).At the beginning,the quantum system is a pure state and the environmental oscillators are in thermodynamic equilibrium with temperature.After a period,the system-environment interactions inspire significant decoherence of the quantum state.Such decoherence is displayed by explicit calculations of the purity and von Neumann entropy of the quantum system.It is worth noting that the decoherence could be significant even in the weak coupling and low temperature case due to the large amount of environmental degrees of freedom.Since the decoherence process is inspired between the quantum system and an ordinary thermal environment here,the thermal decoherence result is quite general. 展开更多
关键词 Quantum decoherence Grand canonical ensemble Oscillators
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牡丹花中不同形态酚类化合物及其抗氧化和α-葡萄糖苷酶抑制活性
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作者 陈玲 王学方 +3 位作者 李智宁 张立攀 李晓 宁二娟 《食品科学》 EI CAS 北大核心 2025年第1期83-89,共7页
对丹凤和香玉两种牡丹花中的游离酚、酯键合态酚、糖苷键合态酚和不溶性结合态酚进行提取,测定不同形态酚类化合物中总酚、总黄酮含量及其主要化合物组成和含量,并对其抗氧化活性和α-葡萄糖苷酶抑制活性进行研究。结果表明,丹凤和香玉... 对丹凤和香玉两种牡丹花中的游离酚、酯键合态酚、糖苷键合态酚和不溶性结合态酚进行提取,测定不同形态酚类化合物中总酚、总黄酮含量及其主要化合物组成和含量,并对其抗氧化活性和α-葡萄糖苷酶抑制活性进行研究。结果表明,丹凤和香玉牡丹花的游离酚的总酚和总黄酮含量最高,总酚含量分别为31.45、32.64 mg/g,总黄酮含量分别为41.11、40.67 mg/g,其次是酯键合态酚和糖苷键合态酚,不溶性结合态酚含量较低;两种牡丹花游离酚均含有17种成分,其主要成分是白藜芦醇、1,2,3,4,6-O-五没食子酰葡萄糖和大波斯菊苷;酯键合态酚、糖苷键合态酚中主要成分是山柰酚-7-O-β-D-葡萄糖苷和大波斯菊苷。不同形态酚类化合物中游离酚的抗氧化活性最强,丹凤、香玉牡丹花游离酚对1,1-二苯基-2-三硝基苯肼自由基、2,2′-联氮-二(3-乙基苯并噻唑-6-磺酸)阳离子自由基清除能力和铁离子还原能力分别为855.03、367.10、230.54μmol/g和499.06、290.64、196.39μmol/g;丹凤和香玉牡丹花的游离酚对α-葡萄糖苷酶抑制活性最强,半抑制浓度分别为12.15、13.87μg/mL。研究结果对丹凤和香玉多酚利用具有一定的参考价值。 展开更多
关键词 牡丹花 游离酚 酯键合态酚 糖苷键合态酚 不溶性结合态酚 抗氧化活性 α-葡萄糖苷酶抑制活性
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A New Kind of FACTS Device for Suppressing Inter Area Oscillations
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作者 倪明 HansGlavitsch 《Journal of Southeast University(English Edition)》 EI CAS 1999年第2期69-77,共9页
As a consequence of interconnections of large power systems electromechanical oscillations appear being known as inter area oscillations. In order to suppress such inter area oscillations, a FACTS device is conceive... As a consequence of interconnections of large power systems electromechanical oscillations appear being known as inter area oscillations. In order to suppress such inter area oscillations, a FACTS device is conceived which is designed on the basis of the analogy between the transmission line model and a longitudinal electromechanical model. The damping action is based on the phenomenon of impedance matching of the transmission line model. Modelling of the overall system, optimal placement and control strategy are being treated. A realistic 420kV longitudinal model and a complex power system model are used for simulation. In the simulation, the time response of this device and the effect of this device even under limiting conditions are studied. The results show that this device suppresses the inter area oscillations effectively. 展开更多
关键词 inter area oscillation FACTS DAMPING
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自激式混合原子自旋振荡器的实验研究
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作者 马千金 李二伟 刘国宾 《原子与分子物理学报》 CAS 北大核心 2025年第4期108-112,共5页
基于碱金属-惰性气体混合自旋体系的原子共磁力计被广泛应用于寻找新相互作用、暗物质粒子等基础物理研究,以及惯性导航与生物磁探测等现实应用领域.基于Rb-Xe原子共磁力计,我们实现了一种自激式的混合原子自旋振荡器.其原理是在z轴方... 基于碱金属-惰性气体混合自旋体系的原子共磁力计被广泛应用于寻找新相互作用、暗物质粒子等基础物理研究,以及惯性导航与生物磁探测等现实应用领域.基于Rb-Xe原子共磁力计,我们实现了一种自激式的混合原子自旋振荡器.其原理是在z轴方向上使用圆偏振光将碱金属原子极化,碱金属与惰性气体原子在高温下发生碰撞,进而将惰性气体的核自旋极化.当外磁场存在时,核自旋磁矩将在磁力矩的作用下以拉莫尔频率绕外磁场进动.在x方向上使用线偏振光进行探测,可得到原子自旋振荡信号,通过将光检信号放大、滤波、移相再施加到横向激励磁场线圈上,产生的交变磁场同步驱动核自旋进动,实现闭环自激的原子自旋无衰减振荡信号.本文从实验角度研究了该自旋振荡器的开环频率响应特性,及闭环状态下的自旋振荡频率移动随增益、相位参数变化的关系.实验结果与前期理论预期基本符合,并为提高该振荡器的频率稳定性提供重要参考. 展开更多
关键词 原子自旋振荡器 频移 增益 相位
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THE BASIC THEORY OF SOLUTIONS OF FUNCTIONAL DIFFERENTIAL EQUATIONS WITH BOUNDED DELAY IN THE SPACE OF INTEGRABLE FUNCTIONS
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作者 刘永清 李远清 《华南理工大学学报(自然科学版)》 EI CAS CSCD 北大核心 1997年第7期67-73,共7页
在可积函数空间中讨论有界滞量泛函微分方程,建立其解的基本理论,包括解的存在性,唯一性及延展性。
关键词 有界滞量的泛函微分方程 存在性 唯一性 延展性 可积函数空间
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