期刊文献+
共找到20篇文章
< 1 >
每页显示 20 50 100
Measure synchronization in hybrid quantum-classical systems
1
作者 Haibo Qiu Yuanjie Dong +1 位作者 Huangli Zhang Jing Tian 《Chinese Physics B》 SCIE EI CAS CSCD 2022年第12期111-116,共6页
Measure synchronization in hybrid quantum-classical systems is investigated in this paper.The dynamics of the classical subsystem is described by the Hamiltonian equations,while the dynamics of the quantum subsystem i... Measure synchronization in hybrid quantum-classical systems is investigated in this paper.The dynamics of the classical subsystem is described by the Hamiltonian equations,while the dynamics of the quantum subsystem is governed by the Schr¨odinger equation.By increasing the coupling strength in between the quantum and classical subsystems,we reveal the existence of measure synchronization in coupled quantum-classical dynamics under energy conservation for the hybrid systems. 展开更多
关键词 measure synchronization quantum measure synchronization hybrid quantum-classical systems
下载PDF
Measure Synchronization on Symplectic Map
2
作者 CHENShao-Ying XUHai-Bo +1 位作者 WANGGuang-Rui CHENShi-Gang 《Communications in Theoretical Physics》 SCIE CAS CSCD 2004年第6期886-894,共9页
Measure synchronization in coupled Hamiltonian systems is a novel synchronization phenomenon. The measure synchronization on symplectic map is observed numerically, for identical coupled systems with different paramet... Measure synchronization in coupled Hamiltonian systems is a novel synchronization phenomenon. The measure synchronization on symplectic map is observed numerically, for identical coupled systems with different parameters. We have found the properties of the characteristic frequency and the amplitude of phase locking in regular motion when the measure synchronization of coupled systems is obtained. The relations between the change of the largest Lyapunov exponent and the course of phase desynchronization are also discussed in coupled systems, some useful results are obtained. A new approach is proposed for describing the measure synchronization of coupled systems numerically,which is advantage in judging the measure synchronization, especially for the coupled systems in nonregular region. 展开更多
关键词 symplectic map measure synchronization phase locking Lyapunov exponent
下载PDF
Bunch-length measurement at a bunch-by-bunch rate based on time–frequency-domain joint analysis techniques and its application
3
作者 Hong-Shuang Wang Xing Yang +2 位作者 Yong-Bin Leng Yi-Mei Zhou Ji-Gang Wang 《Nuclear Science and Techniques》 SCIE EI CAS CSCD 2024年第4期165-175,共11页
This paper presents a new technique for measuring the bunch length of a high-energy electron beam at a bunch-by-bunch rate in storage rings.This technique uses the time–frequency-domain joint analysis of the bunch si... This paper presents a new technique for measuring the bunch length of a high-energy electron beam at a bunch-by-bunch rate in storage rings.This technique uses the time–frequency-domain joint analysis of the bunch signal to obtain bunch-by-bunch and turn-by-turn longitudinal parameters,such as bunch length and synchronous phase.The bunch signal is obtained using a button electrode with a bandwidth of several gigahertz.The data acquisition device was a high-speed digital oscilloscope with a sampling rate of more than 10 GS/s,and the single-shot sampling data buffer covered thousands of turns.The bunch-length and synchronous phase information were extracted via offline calculations using Python scripts.The calibration coefficient of the system was determined using a commercial streak camera.Moreover,this technique was tested on two different storage rings and successfully captured various longitudinal transient processes during the harmonic cavity debugging process at the Shanghai Synchrotron Radiation Facility(SSRF),and longitudinal instabilities were observed during the single-bunch accumulation process at Hefei Light Source(HLS).For Gaussian-distribution bunches,the uncertainty of the bunch phase obtained using this technique was better than 0.2 ps,and the bunch-length uncertainty was better than 1 ps.The dynamic range exceeded 10 ms.This technology is a powerful and versatile beam diagnostic tool that can be conveniently deployed in high-energy electron storage rings. 展开更多
关键词 Bunch-by-bunch diagnostic Bunch-length measurement Synchronous phase measurement Joint time–frequency-domain analysis Longitudinal instability
下载PDF
Different Frequency Synchronization Theory and Its Frequency Measurement Practice Teaching Innovation Based on Lissajous Figure Method 被引量:1
4
作者 Xin Geng Songlin Li +2 位作者 Guangming Huang Baoqiang Du Jianhua Chen 《Journal of Beijing Institute of Technology》 EI CAS 2018年第2期198-205,共8页
According to the requirement of multi-parameter time and frequency measurement without frequency normalization,a different frequency synchronization theory is proposed based on Lissajous figure method and the variatio... According to the requirement of multi-parameter time and frequency measurement without frequency normalization,a different frequency synchronization theory is proposed based on Lissajous figure method and the variation lawof Lissajous figure which are used in practice teaching of frequency measurement. The theory can achieve high-precision transmission and comparison of time and frequency and precise locking and tracking of phase and frequency,improve the level of scientific research on time and frequency for postgraduate,and promote practice teaching innovation of time frequency measurement for undergraduate. Utilizing the ratio of horizontal and vertical inflection point of the Lissajous figure,the nominal frequency of the measured signal is precisely calculated.The frequency deviation between the measured frequency and its nominal frequency can be obtained by combining the turning cycle of the Lissajous figure. By observing the phase relationship between the frequency standard signal and the measured signal,the accurate measurement of the frequency is implemented. Experimental results showthat the direct measurement and comparison better than the 10-11 order of magnitude with common frequency source can be finished between any signal frequencies.The frequency measurement method based on the theory has the advantage of simple operation,quick measurement speed,small error,lownoise and high measurement precision. It plays an important role in time synchronization,communications,metrology,scientific research,educational technology practice and equipment and other fields. 展开更多
关键词 Lissajous figure different frequency synchronization frequency measurement
下载PDF
Resilient Smart Power Grid Synchronization Estimation Method for System Resilience with Partial Missing Measurements
5
作者 Yi Wang Yanxin Liu +3 位作者 Mingdong Wang Venkata Dinavahi Jun Liang Yonghui Sun 《CSEE Journal of Power and Energy Systems》 SCIE EI CSCD 2024年第3期1307-1319,共13页
With the increasing demand for power system stability and resilience,effective real-time tracking plays a crucial role in smart grid synchronization.However,most studies have focused on measurement noise,while they se... With the increasing demand for power system stability and resilience,effective real-time tracking plays a crucial role in smart grid synchronization.However,most studies have focused on measurement noise,while they seldom think about the problem of measurement data loss in smart power grid synchronization.To solve this problem,a resilient fault-tolerant extended Kalman filter(RFTEKF)is proposed to track voltage amplitude,voltage phase angle and frequency dynamically.First,a threephase unbalanced network’s positive sequence fast estimation model is established.Then,the loss phenomenon of measurements occurs randomly,and the randomness of data loss’s randomness is defined by discrete interval distribution[0,1].Subsequently,a resilient fault-tolerant extended Kalman filter based on the real-time estimation framework is designed using the timestamp technique to acquire partial data loss information.Finally,extensive simulation results manifest the proposed RFTEKF can synchronize the smart grid more effectively than the traditional extended Kalman filter(EKF). 展开更多
关键词 Dynamic state estimation Kalman filter partial missing measurements power systems smart grid synchronized measurements
原文传递
Research on synchronous measurement technique of temperature and deformation fields using multispectral camera with bilateral telecentric lens 被引量:1
6
作者 Wenxiong Shi Yangyang Li +4 位作者 Ru Chen Chenghao Zhang Zhanwei Liu Huimin Xie Fei Liu 《Theoretical & Applied Mechanics Letters》 CAS CSCD 2022年第3期137-144,共8页
The hot-section parts easily occur the creep-fatigued interaction under the condition of mechanicalthermal coupled load during the period of service, which may lead to the damage of the parts, and therefore, the measu... The hot-section parts easily occur the creep-fatigued interaction under the condition of mechanicalthermal coupled load during the period of service, which may lead to the damage of the parts, and therefore, the measurement and characterization of thermal-deformed fields of the parts are important to understand its damage process. Aiming at relevant demand, the bilateral telecentric-multispectral imaging system was established, the research of synchronous measurement technique of the temperature and deformation fields was developed. On the one hand, the measurement technology for surface temperature of the object was developed using the two-color images captured by the multispectral camera with bilateral telecentric lens and combined with colorimetric method. On the other hand, the 2 D-DIC measurement technique of the multispectral camera was developed by conducting digital image correlation analysis using the blue light images before and after deformation, which can measure the high temperature deformation field of the object(the blue light images were filtered by multispectral camera).Results showed that the bilateral telecentric lens is used to replace the ordinary optical lens for imaging,which can effectively eliminate the distortion of the multispectral imaging system. Since the temperature measurement process of this measurement system is little affected by the emissivity of the object, therefore, it has excellent robustness. The thermal expansion coefficients of the nickel alloys are evaluated at the temperature ranges of 700–1000℃, indicating this system can achieve the synchronous and precise measurement of the temperature and deformation fields of the object. 展开更多
关键词 Bilateral telecentric-multispectral measuring system Colorimetric method Digital image correlation Synchronous measurement Temperature and deformation fields
下载PDF
Synchronous Measurement of Ultrafast Anisotropy Decay of the B850 in Bacterial LH2 Complex
7
作者 王云鹏 都鲁超 +2 位作者 朱刚贝 王专 翁羽翔 《Chinese Physics Letters》 SCIE CAS CSCD 2015年第2期48-51,共4页
Ultrafast anisotropic decay is a prominent parameter revealing ultrafast energy and electron transfer; however, it is dimcult to be determined reliably owing to the requirement of a simultaneous availability of the pa... Ultrafast anisotropic decay is a prominent parameter revealing ultrafast energy and electron transfer; however, it is dimcult to be determined reliably owing to the requirement of a simultaneous availability of the parallel and perpendieular polarized decay kinetics. Nowadays, any measurement of anisotropic decay is a kind of approach to the exact simultaneity. Here we report a novel method for a synchronous ultrafast anisotropy decay measurement, which can well determine the anisotropy, even at a very early time, as the rising phase of the excitation laser pulse. The anisotropic decay of the B850 in bacteriM light harvesting antenna complex LH2 of rhodobacter sphaeroides in solution at room temperature with coherent excitation is detected by this method, which shows a polarization response time of 30 fs, and the energy transfer from the initial excitation to the bacteriochlorophylls in B850 ring takes about 7Ors. The anisotropic decay that is probed at the red side of the absorption spectrum, such as 880 nm, has an initial value of 0.4, corresponding to simulated emission, while the blue side with an anisotropy of 0.1 contributes to the ground-state bleaching. Our results show that the coherent excitation covering the whole ring might not be realized owing to the symmetry breaking of LH2: from C9 symmetry in membrane to C2 symmetry in solution. 展开更多
关键词 Synchronous measurement of Ultrafast Anisotropy Decay of the B850 in Bacterial LH2 Complex LH
下载PDF
Optimal Placement of Phasor Measurement Units Using a Modified Canonical Genetic Algorithm for Observability Analysis
8
作者 Rodrigo Albuquerque Frazao Aureio Luiz Magalhfies +2 位作者 Denisson Oliveira Shigeaki Lima Igor Santos 《Journal of Mechanics Engineering and Automation》 2014年第3期187-194,共8页
This paper proposes a method for optimal placement of synchronized PMUs (phasor measurement units) in electrical power systems using a MCGA (modified canonical genetic algorithm), which the goal is to determine th... This paper proposes a method for optimal placement of synchronized PMUs (phasor measurement units) in electrical power systems using a MCGA (modified canonical genetic algorithm), which the goal is to determine the minimum number of PMUs, as well as the optimal location of these units to ensure the complete topological observability of the system. In case of more than one solution, a strategy of analysis of the design matrix rank is applied to determine the solution with the lower number of critical measurements. In the proposed method of placement, modifications are made in the crossover and mutation genetic operators, as well as in the formation of the subpopulation, and are considered restrictive hypotheses in the search space to improve the performance in solving the optimization problem. Simulations are performed using the IEEE 14-bus, IEEE 30-bus and New England 39-bus test systems. The proposed method is applied on the IEEE 118-bus test system considering the presence of observable zones formed by conventional measurements. 展开更多
关键词 Synchronized phasor measurement units electrical power systems modified canonical genetic algorithm topologicalobservability critical measurements.
下载PDF
Stability Monitoring and Control of Generation Based on the Synchronized Measurements in Nodes of Its Connection
9
作者 Alexander Fishov Maria Shiller +1 位作者 Anton Dekhterev Vladimir Fishov 《Journal of Energy and Power Engineering》 2015年第1期59-67,共9页
Synchronized distributed measurements of mode parameters create a technical feasibility for development and implementing new technologies of control the mode stability and the admissibility of EPS (electric power sys... Synchronized distributed measurements of mode parameters create a technical feasibility for development and implementing new technologies of control the mode stability and the admissibility of EPS (electric power system) mode. Discussion will focus on different models obtained from data synchronized measurements for operational and automatic emergency control without EPS being totally controlled. According to the proposed technology, the generator's output power restrictions are determined in real-time by the terms a static stability using the generators' mode model as a multipole with connection nodes of generators' electromotive forces (the matrix of SMA (self and mutual admittances) of electromotive forces of generators). Potential applications of the technology are distribution network with the main substation and generators of commensurable capacity, and transmission network with large power plants (generators) distributed into the network. The one-level control system for all of generators with defining the generator's power limits relative to the main substation is implemented in the first case. In the second case, the two-level control system is brought in, based on the separation of large and small generation motion. The results of the method and technology efficiency verification are shown in the paper, by both computer simulations of the power system modes and its physical model. 展开更多
关键词 Power system static stability synchronized measurements normal mode transient mode post emergency mode matrix of self and mutual admittances.
下载PDF
Rheo-optic in situ synchronous study on the gelation behaviour and mechanism of waxy crude oil emulsions 被引量:1
10
作者 Jian Zhao Xiao-Feng Li +1 位作者 Hang Dong Zhi-Hua Wang 《Petroleum Science》 SCIE EI CAS CSCD 2023年第2期1266-1288,共23页
An improved rheo-optic in situ synchronous measurement system was employed to investigate the gelation behaviour and mechanism of waxy crude oil emulsions. By combining transmitted natural light and reflected polarize... An improved rheo-optic in situ synchronous measurement system was employed to investigate the gelation behaviour and mechanism of waxy crude oil emulsions. By combining transmitted natural light and reflected polarized light microscopy, a multiangle composite light source was built to achieve the simultaneous observation of wax crystals and emulsified water droplets, as well as their dynamic aggregation process. Main outcomes on the microscopic mechanism were obtained by developed microscopic image processing method. It was found that the microstructure of W/O waxy crude oil emulsion has the evolution of “individual structure--homogeneous aggregate structure--heterogeneous coaggregate structure--floc structure” during the static cooling, which results in the four stages during gelation process. Different from previous studies, the aggregation of emulsified water droplets was found to be more significant and contributes to the formation and development of the wax crystals-emulsified water droplets coaggregate, which plays a decisive role in the further evolution of the gelled microstructure. Time series microscopic images show the dynamic aggregation of emulsified water droplets and wax crystals. Two different aggregation behaviours between wax crystals and water droplets were observed. That wax crystals can not only embed in gaps between adjacent water droplets and enhance the structure, but also surround the outside of the water droplets and continue to grow resulting in the interconnection of different coaggregates to form a larger floc structure. In addition, correlation between viscoelasticity and microstructure evolution of waxy crude oil emulsions of different water contents was discussed. With increasing water contents, the microstructure is changed from wax crystal flocculation structure as the main skeleton and the emulsified water droplets embedded in it, into the aggregation of emulsified water droplets occupying the main position. When the number of wax crystals and water droplets reaches a certain ratio, did wax crystals form coaggregates with emulsified water droplets, and the remaining wax crystals formed an overall flocculation structure, the viscoelasticity of the waxy crude oil emulsion is the highest. 展开更多
关键词 Waxy crude oil emulsion Rheo-optic in situ synchronous measurement GELATION Microscopic mechanism Structural behaviour
下载PDF
Collective dynamics in a non-dissipative two-coupled pendulum system
11
作者 陈子辰 李博 +1 位作者 邱海波 惠小强 《Chinese Physics B》 SCIE EI CAS CSCD 2014年第5期154-160,共7页
We study the collective dynamics of a non-dissipative two-coupled pendulum system, including phase synchronization (PS) and measure synchronization (MS). We find that as the coupling intensity between the two pend... We study the collective dynamics of a non-dissipative two-coupled pendulum system, including phase synchronization (PS) and measure synchronization (MS). We find that as the coupling intensity between the two pendulums increases, the PS happens prior to the MS. We also present a three-dimensional phase space representation of MS, from which a more detailed information about evolution can be obtained. Fu~.hermore, the order parameters are introduced to describe the phase transition between PS and MS. Finally, through the analysis of the Poincar6 sections, we show that the system exhibits separatrix crossing behavior right at the MS transition point, and as the total initial energy increases, the Hamiltonian chaos will arise with separatrix chaos at the chaotic MS transition point. 展开更多
关键词 two-coupled pendulum system phase synchronization measure synchronization Poincar6 sectionanalysis
下载PDF
A Simplified Nonlinear Model of Vertical Vortex-Induced Force on Box Decks for Predicting Stable Amplitudes of Vortex-Induced Vibrations 被引量:7
12
作者 Le-Dong Zhu Xiao-Liang Meng +1 位作者 Lin-Qing Du Ming-Chang Ding 《Engineering》 SCIE EI 2017年第6期854-862,共9页
Wind-tunnel tests of a large-scale sectional model with synchronous measurements of force and vibration responses were carried out to investigate the nonlinear behaviors of vertical vortex-induced forces (VIFs) on t... Wind-tunnel tests of a large-scale sectional model with synchronous measurements of force and vibration responses were carried out to investigate the nonlinear behaviors of vertical vortex-induced forces (VIFs) on three typical box decks (i.e., fully closed box, centrally slotted box, and semi-closed box). The mechanisms of the onset, development, and self-limiting phenomenon of the vertical vortex-induced vibration (VlV) were also explored by analyzing the energy evolution of different vertical VIF components and their contributions to the vertical VIV responses. The results show that the nonlinear components of the vertical VIF often differ from deck to deck; the most important components of the vertical VIF, governing the stable amplitudes of the vertical VIV responses, are the linear and cubic components of velocity contained in the self-excited aerodynamic damping forces. The former provides a constant negative damping ratio to the vibration system and is thus the essential power driving the development of the VIV amplitude, while the latter provides a positive damping ratio proportional to the square of the vibration velocity and is actually the inherent factor making the VIV amplitude self-limiting. On these bases, a universal simplified nonlinear mathematical model of the vertical VIF on box decks of bridges is presented and verified in this paper; it can be used to predict the stable amplitudes of the vertical VIV of long-span bridges with satisfactory accuracy. 展开更多
关键词 Box deck of bridge Vertical vortex-induced vibration Vertical vortex-induced force Simplified nonlinear model Wind-tunnel test Large-scale sectional model Synchronous measurement of force and vibration
下载PDF
New generation traction power supply system and its key technologies for electrified railways 被引量:6
13
作者 Qunzhan Li 《Journal of Modern Transportation》 2015年第1期1-11,共11页
Unlike the traditional traction power supply system which enables the electrified railway traction sub- station to be connected to power grid in a way of phase rotation, a new generation traction power supply system w... Unlike the traditional traction power supply system which enables the electrified railway traction sub- station to be connected to power grid in a way of phase rotation, a new generation traction power supply system without phase splits is proposed in this paper. Three key techniques used in this system have been discussed. First, a combined co-phase traction power supply system is applied at traction substations for compensating negative sequence current and eliminating phase splits at exits of substations; design method and procedure for this system are presented. Second, a new bilateral traction power supply technology is proposed to eliminate the phase split at section post and reduce the influence of equalizing current on the power grid. Meanwhile, power factor should be adjusted to ensure a proper voltage level of the traction network. Third, a seg- mental power supply technology of traction network is used to divide the power supply arms into several segments, and the synchronous measurement and control technology is applied to diagnose faults and their locations quickly and accurately. Thus, the fault impact can be limited to a min- imum degree. In addition, the economy and reliability of the new generation traction power supply system are analyzed. 展开更多
关键词 New generation traction power supplysystem Combined co-phase power supply Bilateralpower supply Segmental power supply technology Synchronous measurement and control
下载PDF
GCN-LSTM spatiotemporal-network-based method for post-disturbance frequency prediction of power systems 被引量:2
14
作者 Dengyi Huang Hao Liu +1 位作者 Tianshu Bi Qixun Yang 《Global Energy Interconnection》 EI CAS CSCD 2022年第1期96-107,共12页
Owing to the expansion of the grid interconnection scale,the spatiotemporal distribution characteristics of the frequency response of power systems after the occurrence of disturbances have become increasingly importa... Owing to the expansion of the grid interconnection scale,the spatiotemporal distribution characteristics of the frequency response of power systems after the occurrence of disturbances have become increasingly important.These characteristics can provide effective support in coordinated security control.However,traditional model-based frequencyprediction methods cannot satisfactorily meet the requirements of online applications owing to the long calculation time and accurate power-system models.Therefore,this study presents a rolling frequency-prediction model based on a graph convolutional network(GCN)and a long short-term memory(LSTM)spatiotemporal network and named as STGCN-LSTM.In the proposed method,the measurement data from phasor measurement units after the occurrence of disturbances are used to construct the spatiotemporal input.An improved GCN embedded with topology information is used to extract the spatial features,while the LSTM network is used to extract the temporal features.The spatiotemporal-network-regression model is further trained,and asynchronous-frequency-sequence prediction is realized by utilizing the rolling update of measurement information.The proposed spatiotemporal-network-based prediction model can achieve accurate frequency prediction by considering the spatiotemporal distribution characteristics of the frequency response.The noise immunity and robustness of the proposed method are verified on the IEEE 39-bus and IEEE 118-bus systems. 展开更多
关键词 Synchronous phasor measurement Frequency-response prediction Spatiotemporal distribution characteristics Improved graph convolutional network Long short-term memory network Spatiotemporal-network structure
下载PDF
A SVM Based Condition Monitoring of Transmission Line Insulators Using PMU for Smart Grid Environment 被引量:3
15
作者 Kailasam Saranya Chinnusamy Muniraj 《Journal of Power and Energy Engineering》 2016年第3期47-60,共14页
A new methodology for the detection and identification of insulator arc faults for the smart grid environment based on phasor angle measurements is presented in this study and the real time phase angle data are collec... A new methodology for the detection and identification of insulator arc faults for the smart grid environment based on phasor angle measurements is presented in this study and the real time phase angle data are collected using Phasor Measurement Units (PMU). Detection of insulator arcing faults is based on feature extraction and frequency component analysis. The proposed methodology pertains to the identification of various stages of insulator arcing faults in transmission lines network based on leakage current, frequency characteristics and synchronous phasor measurements of voltage. The methodology is evaluated for IEEE 14 standard bus system by modeling the PMU and insulator arc faults using MATLAB/Simulink. The classification of insulator arcs is done using Support Vector Machine (SVM) technique to avoid empirical risk. The proposed methodology using phasor angle measurements employing PMU is used for fault detection/classification of insulator arcing which further helps in efficient protection of the system and its stable operation. In addition, the methodology is suitable for wide area condition monitoring of smart grid rather than end to end transmission lines. 展开更多
关键词 Phasor measurement Units Insulator Arc Feature Extraction Synchronous Phasor measurements Leakage Current Support Vector Machine
下载PDF
Synchronous measurement of tribocharge and force at the footpads of freely moving animals 被引量:3
16
作者 Yi SONG Zhouyi WANG +2 位作者 Jun ZHOU Yang LI Zhendong DAI 《Friction》 SCIE CSCD 2018年第1期75-83,共9页
Hypothesis on electrostatic attraction mechanisms involving the hairy adhesion of climbing animals has been a matter of controversy for several years. The detection of tribocharge and forces at attachment organs of an... Hypothesis on electrostatic attraction mechanisms involving the hairy adhesion of climbing animals has been a matter of controversy for several years. The detection of tribocharge and forces at attachment organs of animals is a practical method of clarifying the dispute with respect to electrostatic attraction in the attachment of animals. Nonetheless, the tribo-electrification is rarely examined in the contact-adhesion of animals(especially in their free and autonomous attachment) due to the lack of available devices. Therefore, the present study involves establishing a method and an apparatus that enables synchronous detection of tribocharge and contact forces to study tribo-electrification in the free locomotion of geckos. A type of a combined sensor unit that consists of a three-dimensional force transducer and a capacitor-based charge probe is used to measure contact forces and tribocharge with a magnitude corresponding to several nano-Coulombs at a footpad of geckos when they climb vertically upward on an acrylic oligomer substrate. The experimental results indicate that tribocharge at the footpads of geckos is related to contact forces and contact areas. The measured charge allows the expectation of an exact attraction with magnitude corresponding to dozens of newtons per square meter and provides a probability of examining tribo-electrification in animal attachment from a macro level. 展开更多
关键词 tribocharge FORCES synchronous measurement ANIMAL free locomotion
原文传递
Improved monochromatic pyrometry for synchronous measurement of full-field temperature and deformation 被引量:1
17
作者 ZHANG JinSong YUE MengKun +4 位作者 WANG JinYang TANG YunLong JIANG JinSong GUI YeWei FENG Xue 《Science China(Technological Sciences)》 SCIE EI CAS CSCD 2021年第9期2033-2046,共14页
Measuring the temperature and deformation synchronously at elevated temperatures is technically challenging and has become a major concern in the evaluation of mechanical properties. In this study, a simple, easy-to-i... Measuring the temperature and deformation synchronously at elevated temperatures is technically challenging and has become a major concern in the evaluation of mechanical properties. In this study, a simple, easy-to-implement, yet effective monochromatic pyrometry is established for non-contact and full-field temperature measurements, which can significantly reduce the error caused by the camera’s channel crosstalk that commonly occurs in the existing improved two-color method. In addition, hightemperature digital image correlation, combined with band-pass filtering and monochromatic illumination, is applied for deformation measurement. Subsequently, an experimental system was set up to validate the accuracy of the proposed method,which consists of a CCD camera for image capturing, a blue bandpass filter for radiation suppression, blue light irradiation for light compensation, and an infrared pyrometer for temperature recording. The results of the thermal heating experiment on the C/SiC sample proved that the selection of camera channel R in monochromatic pyrometry can reduce the error by channel crosstalk,and the proposed method is applicable for synchronous measurement of temperature and deformation. 展开更多
关键词 synchronous measurement monochromatic pyrometry high-temperature DIC
原文传递
Symmetry restoring dynamics in a two-species bosonic Josephson junction by using occasional coupling
18
作者 Jing Tian Yi-Fan Wang Hai-Bo Qiu 《Communications in Theoretical Physics》 SCIE CAS CSCD 2020年第5期113-119,共7页
In this paper,by employing an occasionally coupling scheme in a two-species bosonic Josephson junction,it is found that for nonlocal measure synchronized states appearing in the two dynamic modes,known as 0-phase mode... In this paper,by employing an occasionally coupling scheme in a two-species bosonic Josephson junction,it is found that for nonlocal measure synchronized states appearing in the two dynamic modes,known as 0-phase mode andπphase mode,their broken-symmetry can be restored.Nevertheless,there are dramatic differences for the results.For 0-phase mode,we can restore the broken symmetry by turning the nonlocal MS state into a conventional quasiperiodic MS state.However,for theπ-phase mode,the broken symmetry is restored accompanied by the appearance of chaotic MS states. 展开更多
关键词 symmetry restoring nonlocal measure synchronization bosonic Josephson junction
原文传递
Deployment and demonstration of wide area monitoring system in power system of Great Britain 被引量:1
19
作者 Peter WALL Papiya DATTARAY +8 位作者 Zhaoyang JIN Priyanka MOHAPATRA James YU Douglas WILSON Karine HAY Stuart CLARK Mark OSBORNE Phillip M.ASHTON Vladimir TERZIJA 《Journal of Modern Power Systems and Clean Energy》 SCIE EI 2016年第3期506-518,共13页
The creation of a suitable wide area monitoring system(WAMS) is widely recognized as an essential aspect of delivering a power system that will be secure,efficient and sustainable for the foreseeable future. In Great ... The creation of a suitable wide area monitoring system(WAMS) is widely recognized as an essential aspect of delivering a power system that will be secure,efficient and sustainable for the foreseeable future. In Great Britain(GB), the deployment of the first WAMS to monitor the entire power system in real time was the responsibility of the visualization of real time system dynamics using enhanced monitoring(VISOR) project. The core scope of the VISOR project is to deploy this WAMS and demonstrate how WAMS applications can in the near term provide system operators and planners with clear, actionable information. This paper presents the wider scope of the VISOR project and the GB wide WAMS that has been deployed. Furthermore, the paper describes some of the WAMS applications that have been deployed and provides examples of the measurement device performance issues that have been encountered during the project. 展开更多
关键词 Model validation Line parameter estimation Subsynchronous oscillation Subsynchronous resonance synchronized measurement technology Wide area monitoring
原文传递
A dynamic phasor estimation algorithm based on angle-shifted energy operator 被引量:1
20
作者 JIN XiaNing WANG FuPing WANG ZanJi 《Science China(Technological Sciences)》 SCIE EI CAS 2013年第6期1322-1329,共8页
Under dynamic conditions, the signals of power system have time-varying magnitude and frequency, which might lead to considerable errors for synchrophasor measurement. The traditional discrete Fourier transform (DFT) ... Under dynamic conditions, the signals of power system have time-varying magnitude and frequency, which might lead to considerable errors for synchrophasor measurement. The traditional discrete Fourier transform (DFT) based algorithms used in Phasor Measurement Unit (PMU) are hard to meet the requirements of measurement accuracy because of the existence of spectral leakage. A dynamic phasor measurement algorithm is proposed in this paper in which the input sampled data are considered as non-stationary signals with amplitude modulation-frequency modulation (AM-FM) form, and the measurement is achieved by AM-FM demodulation. An angle-shifted energy operator (ASEO) is used to extract the instantaneous amplitude and low pass differential filter is introduced for frequency estimation. Simulation results indicate that the proposed algorithm can effectively improve the phasor measurement accuracy and has very short response time for PMU under dynamic conditions. 展开更多
关键词 synchronous phasor measurement discrete Fourier transform (DFT) dynamic conditions energy operator
原文传递
上一页 1 下一页 到第
使用帮助 返回顶部