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Experimental Investigation on Vibration Control of Rotor-bearing System with Active Magnetic Exciter 被引量:12
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作者 WANG Weimin GAO Jinji +1 位作者 HUANG Liquan XIN Zhengqiu 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2011年第6期1013-1021,共9页
Vibration control is an efficient way to minimize a rotating machine’s vibration level so that its vibration fault-free can be realized.While,several factors,such as unbalance,misalignment and instability,contribute ... Vibration control is an efficient way to minimize a rotating machine’s vibration level so that its vibration fault-free can be realized.While,several factors,such as unbalance,misalignment and instability,contribute to the serious vibration of rotating machines.It is necessary that one apparatus can depress vibration caused by two or more reasons.The fault self-recovery(FSR) mechanism is introduced and investigated.Strategies of vibration control are investigated theoretically using numerical method firstly.Active magneticelectric exciter(AME) are selected as the actuator of a FSR device because it can provide suitable force by varying the control current in the exciters depending upon a proportional and derivative control law.By numerical study,it is indicate that only a small control force is needed to improve stability margins of the compressor and prevent subsynchronous vibration fault efficiently.About synchronous vibration,three control strategies,searching in whole circle,fast optimizing control(FOC),and none mistaking control,are investigated to show which of the control strategy can realize the fault self-recovery in the shortest time.Experimental study is conducted on a test rig with variable rotating speed.Results of the test indicate that the non-mistake control strategy can minimize synchronous vibration in less than three seconds.The proposed research can provide a new insight for subsynchronous and synchronous vibration restraining about centrifugal compressor. 展开更多
关键词 vibration control rotor-bearing system active magnetic exciter subsynchronous
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Separate Control of High Frequency Electro-hydraulic Vibration Exciter 被引量:7
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作者 JIA Wen'ang RUAN Jian REN Yan 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2011年第2期293-302,共10页
The working frequency of the conventional electro-hydraulic vibration exciters,which consist of a servo valve and a hydraulic cylinder,is generally restricted within a narrow range due to limited frequency response ca... The working frequency of the conventional electro-hydraulic vibration exciters,which consist of a servo valve and a hydraulic cylinder,is generally restricted within a narrow range due to limited frequency response capability of the servo valve itself.To counteract such restriction,a novel scheme for an electro-hydraulic vibrator,controlled by a two-dimensional valve(2D valve)and a bias valve in parallel,is therefore proposed.The frequency,amplitude and offset are independently controlled by rotary speed,axial sliding of the spool of the 2D valve and axial sliding of the spool of the bias valve.The principle of separate control was presented and the regulation approach of frequency,amplitude and offset was discussed.A mathematical model of the hydraulic power mechanism for the proposed vibration exciter was established to investigate the relationship between the amplitude and the axial sliding of the 2D valve'spool,as well as that between the offset and the axial sliding of the bias valve's spool at various frequencies.An experimental system was built to validate the theoretical analysis.It is verified that the 2D exciter is capable of working smoothly in a frequency range of 5-200 Hz.And its frequency,amplitude and offset can be controlled respectively by either closed loop or open loop method.There is a linear relationship between the output amplitude and the spool axial opening of the 2D valve until a point when the flow rate becomes saturate and the amplitude remains constant.The offset displacement of the cylinder's piston is linearly proportional to the axial displacement of the spool of the bias valve,when the valve opening is less than 25%.Thereafter,the slop of the offset curve decreases and tends to saturate.The proposed electro-hydraulic vibration controlled by the 2D valve not only facilitates the realization of high-frequency electro-hydraulic vibration,the high-accuracy of vibration can also be achieved by means of independent controls to the frequency,amplitude and offset. 展开更多
关键词 control valves electro-hydraulic system vibration exciter dynamics characteristics
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Mechanism of electro-hydraulic exciter for new tamping device 被引量:6
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作者 刘毅 龚国芳 +2 位作者 杨华勇 韩冬 杨学兰 《Journal of Central South University》 SCIE EI CAS 2014年第2期511-520,共10页
A new tamping device which is driven by an electrohydraulic exciter was proposed to overcome the limitations of mechanically driven devices.The double-rod oscillation cylinder drives the tamping arm to realize vibrati... A new tamping device which is driven by an electrohydraulic exciter was proposed to overcome the limitations of mechanically driven devices.The double-rod oscillation cylinder drives the tamping arm to realize vibration.A new spin valve was designed in order to fulfill dynamic state requirements of the oscillation cylinder.Parametric analysis was carried out by establishing mathematic model.Then,the relationships among the structure of valve port and the frequency,amplitude,output shock force of the cylinder were researched.An experimental device of the electrohydraulic exciter was established to validate the theoretical results.The signals were acquired by AVANT dynamic signal analyser of vibration.The results show that new tamping device can satisfy all kinds of complex working conditions with the flexible adjustment of frequency and amplitude. 展开更多
关键词 tamping device spin valve oscillation cylinder electro-hydraulic exciter variable damping parametric analysis
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Non-Contact Electromagnetic Exciter Design with Linear Control Method
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作者 WANG Lin XIONG Xianzhi XU Hua 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2017年第1期135-143,共9页
A non-contact type force actuator is necessary for studying the dynamic performance of a high-speed spindle system owing to its high-speed operating conditions. A non-contact electromagnetic exciter is designed for id... A non-contact type force actuator is necessary for studying the dynamic performance of a high-speed spindle system owing to its high-speed operating conditions. A non-contact electromagnetic exciter is designed for identifying the dynamic coefficients of journal bearings in high-speed grinding spindles. A linear force control method is developed based on PID controller. The influence of amplitude and frequency of current, misalignment and rotational speed on magnetic field and excitation force is investigated based on two-dimensional finite element analysis. The electromagnetic excitation force is measured with the auxiliary coils and calibrated by load cells. The design is validated by the experimental results. Theoretical and experimental investigations show that the proposed design can accurately generate linear excitation force with sufficiently large amplitude and higher signal to noise ratio. Moreover, the fluctuations in force amplitude are reduced to a greater extent with the designed linear control method even when the air gap changes due to the rotor vibration at high-speed conditions. Besides, it is possible to apply various types of excitations: constant, synchronous, and non-synchronous excitation forces based on the proposed linear control method. This exciter can be used as linear-force exciting and controlling system for dynamic performance study of different high-speed rotor-bearing systems. 展开更多
关键词 non-contact excitation electromagnetic exciter journal bearing finite element analysis
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Analysis on the Pressure Fluctuation Law of a Hydraulic Exciting System with a Wave-exciter 被引量:1
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作者 WEI Xiu-ye KOU Zi-ming LU Zi-rong 《International Journal of Plant Engineering and Management》 2011年第4期208-214,共7页
A hydraulic exciting system with a wave exciter has been constructed in order to study the hydraulic vibra- tion law. The system consists of an oil source, wave-exciter and oil cylinder, and is controlled by a wave-ex... A hydraulic exciting system with a wave exciter has been constructed in order to study the hydraulic vibra- tion law. The system consists of an oil source, wave-exciter and oil cylinder, and is controlled by a wave-exciter. The working principle of the hydraulic exciting system and wave exciter has been analyzed, and its excitation process has been illustrated. The law of every pipe's pressure fluctuation of the system is obtained by experiment. The theo- retical analysis and experimental data prove that the pipeline pressure periodically changes and the pipeline pressure fluctuation frequency is independently controlled by the excitation frequency of the wave-exciter. Every pipelinc's pressure wave is produced by system flow fluctuation and water hammer coupling. The pressure fluctuation rules of the system provide a theoretical basis for the study of the associated liberation system. 展开更多
关键词 hydraulic exciting system wave-exciter pressure fluctuation
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Giant Magnetostrictive Material Exciter for Panel Loudspeaker
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作者 王睿 张永发 《Journal of Beijing Institute of Technology》 EI CAS 2008年第3期361-364,共4页
The exciter component in a panel loudspeaker has a profound effect on the overall performance of the system. The equivalent circuit analysis of the combination of giant magnetostrictive material exciter and distribute... The exciter component in a panel loudspeaker has a profound effect on the overall performance of the system. The equivalent circuit analysis of the combination of giant magnetostrictive material exciter and distributed mode panel is introduced and how exciter parameters influence panel lo'udspeaker' s performance is discussed. Numerical predictions are given in order to show how these influences are manifested. 展开更多
关键词 panel loudspeaker giant magnetostrictive material exciter far-field sound pressure
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The Analysis and Improving of the Microwave Exciter in the Lower Hybrid Wave System
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作者 ZENG Hao BAI Xingyu RAO Jun 《Southwestern Institute of Physics Annual Report》 2004年第1期65-67,共3页
When we carry out lower hybrid wave heating and current driving plasma experiment at tokamak, we need mega-watt order of microwave power. The microwave signal at frequency of 2450 MHz is generated by a microwave ex... When we carry out lower hybrid wave heating and current driving plasma experiment at tokamak, we need mega-watt order of microwave power. The microwave signal at frequency of 2450 MHz is generated by a microwave exciter. According to the experiment's demands, the microwave exciter must provide output power of 1.5~ 2. 5 W with stabilized frequency and amplitude tobe used as the klystron input. Being amplified by the klystron, the microwave signal is transmitted through the transmitting system to the antenna and is emitted into the HL-2A tokamak. So we can see that the microwave exciter's function is very important to the lower hybrid wave heating and current driving plasma experiment. 展开更多
关键词 Lower hybrid wave Microwave exciter
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The Design of the Microwave Exciter for Klystron
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作者 ZENG Hao RAO Jun 《Southwestern Institute of Physics Annual Report》 2005年第1期63-64,共2页
To carry out lower hybrid wave heating and current drive plasma experiment on tokamak, we need mega-watt order of microwave power generated by the parallel-running klystrons. Those klystrons must be driven by the micr... To carry out lower hybrid wave heating and current drive plasma experiment on tokamak, we need mega-watt order of microwave power generated by the parallel-running klystrons. Those klystrons must be driven by the microwave exciter. Now our microwave exciter is used for many years and its performance is decreased very much. It can not satisfy any more the hybrid wave heating and current drive plasma experiment. So we set out to design a new microwave exciter that is consist of the microwave solid components, amplitudestabilization control, modularization design with multitude-outputs, microwave phase control in order to satisfy the demand of the different work in the hybrid wave heating and current drive plasma experiment. 展开更多
关键词 Microwave exciter Klystron
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Robust control of exciting force for vibration control system with multi-exciters 被引量:10
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作者 SONG QiaoZhi YANG ZhiChun WANG Wei 《Science China(Technological Sciences)》 SCIE EI CAS 2013年第10期2516-2524,共9页
Due to the dynamical character of electromagnetic exciter and the coupling between structure and exciter(s),the actual output force acting on the structure is usually not equal to the exact value that is supposed to b... Due to the dynamical character of electromagnetic exciter and the coupling between structure and exciter(s),the actual output force acting on the structure is usually not equal to the exact value that is supposed to be,especially when multi-exciters are used as actuators to precisely actuate large flexible structure.It is necessary to consider these effects to ensure the force generated by each exciter is the same as required.In this paper,a robust control method is proposed for the multi-input and multi-output(MIMO)structural vibration control system to trace the target actuating force of each exciter.A special signal is designed and put into the coupled mul-ti-exciter-structure system,and the input and output signals of the system are used to build a dynamic model involving both the dynamical characters of the exciters and the structure using the subspace identification method.Considering the uncertainty factors of the multi-exciter/structure system,an H-infinity robust controller is designed to decouple the coupling between structure and exciters based on the identified system model.A MIMO vibration control system combined with a flexible plate and three electromagnetic exciters is adopted to demonstrate the proposed method,both numerical simulation and model experiments showing that the output force of each exciter can trace its target force accurately within the requested frequency band. 展开更多
关键词 multi-exciters system exciting force control subspace identification robust control experiment modeling
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Epilepsy therapy beyond neurons: Unveiling astrocytes as cellular targets
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作者 Yuncan Chen Jiayi Hu +5 位作者 Ying Zhang Lulu Peng Xiaoyu Li Cong Li Xunyi Wu Cong Wang 《Neural Regeneration Research》 2026年第1期23-38,共16页
Epilepsy is a leading cause of disability and mortality worldwide. However, despite the availability of more than 20 antiseizure medications, more than one-third of patients continue to experience seizures. Given the ... Epilepsy is a leading cause of disability and mortality worldwide. However, despite the availability of more than 20 antiseizure medications, more than one-third of patients continue to experience seizures. Given the urgent need to explore new treatment strategies for epilepsy, recent research has highlighted the potential of targeting gliosis, metabolic disturbances, and neural circuit abnormalities as therapeutic strategies. Astrocytes, the largest group of nonneuronal cells in the central nervous system, play several crucial roles in maintaining ionic and energy metabolic homeostasis in neurons, regulating neurotransmitter levels, and modulating synaptic plasticity. This article briefly reviews the critical role of astrocytes in maintaining balance within the central nervous system. Building on previous research, we discuss how astrocyte dysfunction contributes to the onset and progression of epilepsy through four key aspects: the imbalance between excitatory and inhibitory neuronal signaling, dysregulation of metabolic homeostasis in the neuronal microenvironment, neuroinflammation, and the formation of abnormal neural circuits. We summarize relevant basic research conducted over the past 5 years that has focused on modulating astrocytes as a therapeutic approach for epilepsy. We categorize the therapeutic targets proposed by these studies into four areas: restoration of the excitation–inhibition balance, reestablishment of metabolic homeostasis, modulation of immune and inflammatory responses, and reconstruction of abnormal neural circuits. These targets correspond to the pathophysiological mechanisms by which astrocytes contribute to epilepsy. Additionally, we need to consider the potential challenges and limitations of translating these identified therapeutic targets into clinical treatments. These limitations arise from interspecies differences between humans and animal models, as well as the complex comorbidities associated with epilepsy in humans. We also highlight valuable future research directions worth exploring in the treatment of epilepsy and the regulation of astrocytes, such as gene therapy and imaging strategies. The findings presented in this review may help open new therapeutic avenues for patients with drugresistant epilepsy and for those suffering from other central nervous system disorders associated with astrocytic dysfunction. 展开更多
关键词 ASTROCYTE cellular microenvironment drug resistance EPILEPSY EXCITABILITY homeostasis metabolism neural networks NEUROINFLAMMATION neuron
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Performance and Microscopic Influence Mechanism of Solidified Cadmium Contaminated Soil by Rice Husk Ash Based Geopolymer
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作者 CHEN Wei HAN Jianhong +5 位作者 YU Hongbao XU Hong WANG Ying FAN Wenxiao ZHAO Lina LIU Peijie 《Journal of Wuhan University of Technology(Materials Science)》 2026年第1期171-178,共8页
In order to realize the comprehensive utilization of industrial solid waste rice husk ash and heavy metal cadmium contaminated soil,rice husk ash-based geopolymer prepared by alkaline activator was used to modify cadm... In order to realize the comprehensive utilization of industrial solid waste rice husk ash and heavy metal cadmium contaminated soil,rice husk ash-based geopolymer prepared by alkaline activator was used to modify cadmium contaminated soil.The main physical and chemical properties of rice husk ash were clarified by SEM,XRF and X-ray diffraction.The unconfined compressive strength test and toxicity leaching test were carried out on the modified soil.Combined with FTIR and TG micro-level,the solidification mechanism of rice husk ash-based geopolymer solidified cadmium contaminated soil was discussed.The results show that the strength of geopolymer modified soil is significantly higher than that of plain soil,and the unconfined compressive strength at 7 d age is 4.2 times that of plain soil.The strength of modified soil with different dosage of geopolymer at 28 d age is about 36% to 40% higher than that of modified soil at 7 d age.Geopolymer has a significant effect on the leaching of heavy metals in contaminated soil.When the cadmium content is 100 mg/kg,it meets the standard limit.In the process of complex depolymerization-condensation reaction,on the one hand,geopolymers are cemented and agglomerated to form a complex spatial structure,which affects the macro and micro characteristics of soil.On the other hand,it has significant adsorption,precipitation and replacement effects on heavy metal ions in soil,showing good strength and low heavy metal leaching toxicity. 展开更多
关键词 rice husk ash alkali excitation heavy metals curing mechanism
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Noradrenergic excitation of astrocytes supports cognitive reserve
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作者 Robert Zorec Alexei Verkhratsky 《Neural Regeneration Research》 2026年第4期1546-1547,共2页
The concept of the brain cognitive reserve is derived from the well-acknowledged notion that the degree of brain damage does not always match the severity of clinical symptoms and neurological/cognitive outcomes.It ha... The concept of the brain cognitive reserve is derived from the well-acknowledged notion that the degree of brain damage does not always match the severity of clinical symptoms and neurological/cognitive outcomes.It has been suggested that the size of the brain(brain reserve) and the extent of neural connections acquired through life(neural reserve) set a threshold beyond which noticeable impairments occur.In contrast,cognitive reserve refers to the brain's ability to adapt and reo rganize stru cturally and functionally to resist damage and maintain function,including neural reserve and brain maintenance,resilience,and compensation(Verkhratsky and Zorec,2024). 展开更多
关键词 ASTROCYTES brain reserve cognitive reserve clinical symptoms noradrenergic excitation neural reserve neural connections brain cognitive reserve
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Synaptic and synchronic impairments in subcortical brain regions associated with early non-cognitive dysfunction in Alzheimer's disease
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作者 Nicolás Riffo-Lepe Juliana González-Sanmiguel +5 位作者 Lorena Armijo-Weingart Paulina Saavedra-Sieyes David Hernandez Gerson Ramos Loreto S.San Martín Luis G.Aguayo 《Neural Regeneration Research》 2026年第1期248-264,共17页
For many decades,Alzheimer's disease research has primarily focused on impairments within cortical and hippocampal regions,which are thought to be related to cognitive dysfunctions such as memory and language defi... For many decades,Alzheimer's disease research has primarily focused on impairments within cortical and hippocampal regions,which are thought to be related to cognitive dysfunctions such as memory and language deficits.The exact cause of Alzheimer's disease is still under debate,making it challenging to establish an effective therapy or early diagnosis.It is widely accepted that the accumulation of amyloid-beta peptide in the brain parenchyma leads to synaptic dysfunction,a critical step in Alzheimer's disease development.The traditional amyloid cascade model is initiated by accumulating extracellular amyloid-beta in brain areas essential for memory and language.However,while it is possible to reduce the presence of amyloid-beta plaques in the brain with newer immunotherapies,cognitive symptoms do not necessarily improve.Interestingly,recent studies support the notion that early alterations in subcortical brain regions also contribute to brain damage and precognitive decline in Alzheimer's disease.A body of recent evidence suggests that early Alzheimer's disease is associated with alterations(e.g.,motivation,anxiety,and motor impairment)in subcortical areas,such as the striatum and amygdala,in both human and animal models.Also,recent data indicate that intracellular amyloid-beta appears early in subcortical regions such as the nucleus accumbens,locus coeruleus,and raphe nucleus,even without extracellular amyloid plaques.The reported effects are mainly excitatory,increasing glutamatergic transmission and neuronal excitability.In agreement,data in Alzheimer's disease patients and animal models show an increase in neuronal synchronization that leads to electroencephalogram disturbances and epilepsy.The data indicate that early subcortical brain dysfunctions might be associated with non-cognitive symptoms such as anxiety,irritability,and motivation deficits,which precede memory loss and language alterations.Overall,the evidence reviewed suggests that subcortical brain regions could explain early dysfunctions and perhaps be targets for therapies to slow disease progression.Future research should focus on these non-traditional brain regions to reveal early pathological alterations and underlying mechanisms to advance our understanding of Alzheimer's disease beyond the traditionally studied hippocampal and cortical circuits. 展开更多
关键词 Alzheimer's disease AMPA receptors AMYGDALA epilepsy gamma-aminobutyric acid GLUTAMATE hippocampus NEURODEGENERATION neuronal excitability N-methyl-D-aspartate receptors non-cognitive nucleus accumbens
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Multi-shell Au@Rh nanoantenna reactor with collective plasmonic excitation for photothermal CO_(2)methanation
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作者 Hengrui Zhao Jiazheng Wang +4 位作者 Yunhao Song Dehui Sun Qiang Zhang Wei Lu Haiqing Wang 《Nano Research》 2026年第1期356-366,共11页
The photothermal pathway for converting carbon dioxide(CO_(2))into hydrocarbons presents an effective and straightforward production for solar fuels.Nonetheless,the rational design of a robust solar-driven catalytic s... The photothermal pathway for converting carbon dioxide(CO_(2))into hydrocarbons presents an effective and straightforward production for solar fuels.Nonetheless,the rational design of a robust solar-driven catalytic system for efficient CO_(2)conversion remains a persistent challenge.In this work,we elaborately construct a multi-shell Au@Rh nanoantenna reactor for photothermal CO_(2)methanation.The plasmonically active multi-shell Au structure serves as“antenna”,and the catalytically active Rh nanoparticles function as“reactor”.The reactor exhibits a superior CH_(4) yield rate and nearly 100% selectivity,in comparison with the other Au structures(single-shell(SS)and nanoparticle)and the kinds of active sites(Ru,Ir,and Co).The well-arranged Au nanoparticles in multi-shell structure provide the collective plasmon-coupled excitation,leading to the strong localized surface plasmon resonance(LSPR)effect.Then,the antenna could convert the wide-spectrum solar energy to high surface temperature and enhanced electric field.The in-situ spectra and theoretical calculation indicate that the CO_(2)methanation reaction in Au@Rh nanoantenna reactor follows the formyl pathway.The strong electron-proton coupling transfer ability of Au@Rh nanoantenna reactor contributes to the complex reaction pathway for CO_(2)methanation.Especially,compared with Au catalyst,both the formation of intermediate and the key transformation from to in Au@Rh nanoantenna reactor were promoted through the adequate supply of proton-electron pair and the strong interaction between Au and Rh sites.The ingenious design for nanoantenna reactor and the new findings in photothermal CO_(2)methanation will inspire the development of mild hydrogenation for boosting CO_(2)-to-fuel conversion. 展开更多
关键词 nanoantenna reactor photothermal catalysis CO_(2)reduction CO_(2)methanation collective plasmon excitation
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The second near-infrared (NIR-II) window excitable/emissive organic/polymeric fluorescent molecules for bioimaging application 被引量:1
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作者 Guannan Liu Chenguang Wang Geyu Lu 《Journal of Innovative Optical Health Sciences》 2025年第3期25-43,共19页
The fluorescence imaging (FLI) in the second near-infrared window (NIR-II, 1000–1700nm) has attracted considerable attention in the past decade. In contrast to conventional NIR-I window excitation (808nm/980nm), FLI ... The fluorescence imaging (FLI) in the second near-infrared window (NIR-II, 1000–1700nm) has attracted considerable attention in the past decade. In contrast to conventional NIR-I window excitation (808nm/980nm), FLI with NIR-II window excitation (1064nm/other wavelength beyond 1000nm) can afford deeper tissue penetration depth with high clarity due to the merits of suppressed photon scattering and diminished autofluorescence. In this review, we have summarized NIR-II window excitable/emissive organic/polymeric fluorophores recently developed. The characteristics of these fluorophores such as chemical structures and photophysical properties have also been critically discussed. Furthermore, the latest development of noninvasive in vivo FLI with NIR-II excitation was highlighted. The ideal imaging results emphasized the importance of NIR-II excitation of these fluorophores in enabling deep tissue penetration and high-resolution imaging. Finally, a perspective on the challenges and prospects of NIR-II excitable/emissive organic/polymeric fluorophores was also discussed. We expected this review will be served as a source of inspiration for researchers, stimulating the creation of novel NIR-II excitable fluorophores and fostering the development of bioimaging applications. 展开更多
关键词 Fluorescence imaging NEAR-INFRARED excitation wavelength organic fluorophores conjugated polymers
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Dynamic Behavior of a Pipe Conveying a Gas-Liquid Two-Phase Flow Under External Excitations 被引量:1
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作者 FU Guang-ming WANG Xiao +4 位作者 JIAO Hui-lin WANG Bo-ying SHAN Zheng-feng SUN Bao-jiang SU Jian 《China Ocean Engineering》 2025年第5期822-838,共17页
This work investigated the dynamic behavior of vertical pipes conveying gas-liquid two-phase flow when subjected to external excitations at both ends.Even with minimal excitation amplitude,resonance can occur when the... This work investigated the dynamic behavior of vertical pipes conveying gas-liquid two-phase flow when subjected to external excitations at both ends.Even with minimal excitation amplitude,resonance can occur when the excitation frequency aligns with the natural frequency of the pipe,significantly increasing the degree of operational risk.The governing equation of motion based on the Euler-Bernoulli beam is derived for the relative deflection with stationary simply supported ends,with the effects of the external excitations represented by source terms distributed along the pipe length.The fourth-order partial differential equation is solved via the generalized integral transform technique(GITT),with the solution successfully verified via comparison with results in the literature.A comprehensive analysis of the vibration phenomena and changes in the motion state of the pipe is conducted for three classes of external excitation conditions:same frequency and amplitude(SFSA),same frequency but different amplitudes(SFDA),and different frequencies and amplitudes(DFDA).The numerical results show that with increasing gas volume fraction,the position corresponding to the maximum vibration displacement shifts upward.Compared with conditions without external excitation,the vibration displacement of the pipe conveying two-phase flow under external excitation increases significantly.The frequency of external excitation has a significant effect on the dynamic behavior of a pipe conveying two-phase flow. 展开更多
关键词 pipe conveying fluid integral transform two-phase flow external excitations dynamic response forced vibrations
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Characteristics and phytotoxicity of hydrochar-derived dissolved organic matter:Effects of feedstock type and hydrothermal temperature 被引量:1
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作者 Qianqian Lang Xuan Guo +8 位作者 Chao Wang Lingyao Li Yufei Li Junxiang Xu Xiang Zhao Jijin Li Bensheng Liu Qinping Sun Guoyuan Zou 《Journal of Environmental Sciences》 2025年第3期139-148,共10页
The dissolved organic matter(DOM)with high mobility and reactivity plays a crucial role in soil.In this study,the characteristics and phytotoxicity ofDOMreleased fromthe hydrochars prepared from different feedstocks(c... The dissolved organic matter(DOM)with high mobility and reactivity plays a crucial role in soil.In this study,the characteristics and phytotoxicity ofDOMreleased fromthe hydrochars prepared from different feedstocks(cowmanure,corn stalk and Myriophyllum aquaticum)under three hydrothermal carbonization(HTC)temperatures(180,200 and 220°C)were evaluated.The results showed that the hydrochars had high dissolved organic carbon content(20.15 to 37.65 mg/g)and its content showed a gradual reduction as HTC temperature increased.Three fluorescent components including mixed substance of fulvic acid-like and humic acid-like substances(C1,30.92%-58.32%),UVA humic acid-like substance(C2,25.27%-29.94%)and protein-like substance(C3,11.74%-41.92%)were identified in hydrochar DOM by excitation emission matrix spectra coupled with parallel factor analysis.High HTC temperature increased the relative proportion of aromatic substances(C1+C2)and humification degree of hydrochar DOM from cow manure,while it presented adverse effects on the hydrochar DOM from corn stalk and Myriophyllum.aquaticum.The principal component analysis suggested that feedstock type and HTC temperature posed significant effects on the characteristics of hydrochar DOM.Additionally,seed germination test of all hydrochar DOM demonstrated that the root length was reduced by 8.88%-26.43%in contrast with control,and the germination index values were 73.57%-91.12%.These findings provided new insights into the potential environmental effects for hydrochar application in soil. 展开更多
关键词 Hydrochar Hydrothermal temperature Dissolved organic matter Excitation emission matrix Parallel factor analysis PHYTOTOXICITY
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Donor-acceptor type organic cocrystals for deep-red circularly polarized luminescence and two-photon excited emission 被引量:1
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作者 Jiawei Li Cheng Chen Mingyan Wu 《Chinese Journal of Structural Chemistry》 2025年第3期21-25,共5页
Circularly polarized luminescence(CPL)and two-photon absorption(TPA)materials have garnered considerable attentions due to their minimal energy loss and superior optical penetration[1,2].However,the current challenge ... Circularly polarized luminescence(CPL)and two-photon absorption(TPA)materials have garnered considerable attentions due to their minimal energy loss and superior optical penetration[1,2].However,the current challenge lies in the absence of well-developed strategies for designing materials that combine these two exceptional optical properties. 展开更多
关键词 deep red circularly polarized luminescence organic cocrystals two photon absorption two photon excited emission circularly polarized luminescence donor acceptor circularly polarized luminescence cpl optical properties
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Rydberg-State Excitation and Ionization of Argon Atoms Subject to Strong Circularly Polarized Two-Color Few-Cycle Laser Fields
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作者 Zhiqiang Wang Wei Quan +3 位作者 Yanlan Wang Xiaolei Hao Jing Chen Xiaojun Liu 《Chinese Physics Letters》 2025年第5期12-20,共9页
The ultrafast excitation dynamics of atoms and molecules exposed to circularly polarized two-color(CPTC)laser fields constitute a fascinating topic in attosecond science. Although extensive research has established th... The ultrafast excitation dynamics of atoms and molecules exposed to circularly polarized two-color(CPTC)laser fields constitute a fascinating topic in attosecond science. Although extensive research has established the relationship between the Rydberg state excitation(RSE) yields and the CPTC field parameters, such as field amplitude ratios and helicity of two components, the role of the relative phase(φ) in modulating RSE efficiency remains unclear. In this work, we theoretically investigate the φ dependence of RSE and ionization yields in the co-rotating and counter-rotating circularly polarized two-color(CPTC) few-cycle laser fields by a semiclassical model. We find that, in co-rotating CPTC fields, both RSE and ionization yields display pronounced oscillations as a function of φ and these oscillations are significantly suppressed in the counter-rotating configuration, particularly for ionization yields. Moreover, the ratio of RSE to ionization yields exhibits an out-of-phase oscillatory pattern between low-and high-intensity regimes. These results can be comprehended by the unique feature of φ dependence of CPTC few-cycle fields, based on our semiclassical analysis. Our results demonstrate that phase-controlled CPTC fields offer a versatile tool for steering ultrafast ionization and RSE dynamics of atoms and molecules. 展开更多
关键词 ionization theoretically investigate dependence ultrafast excitation dynamics field parameters helicity two components attosecond science rydberg state excitation rse Rydberg state excitation
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Does acupuncture at motor-related acupoints affect corticospinal excitability?A systematic review and meta-analysis
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作者 Renming Liu Aung Aung Kywe Moe +2 位作者 Weiting Liu Maryam Zoghi Shapour Jaberzadeh 《Journal of Integrative Medicine》 2025年第2期113-125,共13页
Background:Acupuncture is widely used in modulating brain excitability and motor function,as a form of complementary and alternative medicine.However,there is no existing meta-analysis evaluating the effectiveness and... Background:Acupuncture is widely used in modulating brain excitability and motor function,as a form of complementary and alternative medicine.However,there is no existing meta-analysis evaluating the effectiveness and safety of acupuncture on corticospinal excitability(CSE),and the credibility of the evidence has yet to be quantified.Objective:This study was designed to assess the efficacy and safety of electroacupuncture(EA)and manual acupuncture(MA)in enhancing brain excitability,specifically focusing on CSE as measured by transcranial magnetic stimulation(TMS).Search strategy:This study followed a systematic approach,searching 9 databases up to August 2024 and examining grey literature,in compliance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines.Inclusion criteria:Studies were included if they compared the clinical efficacy of EA or MA with sham acupuncture,no treatment or usual training.Data extraction and analysis:Three investigators independently conducted literature screening,data extraction,and risk of bias assessment.The primary outcome focused on motor-evoked potentials as measured by TMS,with treatment effects quantified using mean differences or standardized mean differences between pre-and post-treatment.Subgroup analyses were conducted using mixed-effects models,while random-effects or fixed-effects models were used to estimate average treatment differences across studies.Results:Based on 34 studies involving 1031 adults,acupuncture techniques significantly enhanced CSE.EA had a greater impact than MA,with effect sizes of 0.53 mV vs 0.43 mV(95%confidence interval[CI]:[0.30,0.76],P<0.00001 vs 95%CI:[0.28,0.59],P<0.00001).The 5 most frequently used acupoints were LI4(Hegu,32 times),ST36(Zusanli,10 times),LI11(Quchi,7 times),TE5(Waiguan,6 times),and GB34(Yanglingquan,5 times).Conclusion:This systematic review indicates that both EA and MA could effectively and safely enhance CSE,bringing the corticospinal pathway closer to the threshold for firing,which may ultimately improve motor function.LI4,ST36,LI11,TE5 and GB34 are the most commonly used acupoints. 展开更多
关键词 ACUPUNCTURE Brain excitability Corticospinal excitability Motor-related acupoints Motor function
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