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Transfer characteristics of dynamic biochemical signals in non-reversing pulsatile flows in a shallow Y-shaped microfluidic channel: signal filtering and nonlinear amplitude-frequency modulation
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作者 Zongzheng CHEN Weimo YUAN +4 位作者 A.R.AZIZ Zhengming GAO Depei ZENG Bo LIU Kairong QIN 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI CSCD 2017年第10期1481-1496,共16页
The transports of the dynamic biochemical signals in the non-reversing pulsatile flows in the mixing microchannel of a Y-shaped microfluidic device are ana- lyzed. The results show that the mixing micro-channel acts a... The transports of the dynamic biochemical signals in the non-reversing pulsatile flows in the mixing microchannel of a Y-shaped microfluidic device are ana- lyzed. The results show that the mixing micro-channel acts as a low-pass filter, and the biochemical signals are nonlinearly modulated by the pulsatile flows, which depend on the biochemical signal frequency, the flow signal frequency, and the biochemical signal transporting distance. It is concluded that, the transfer characteristics of the dynamic biochemical signals, which are transported in the time-varying flows, should be carefully considered for better loading biochemical signals on the cells cultured on the bottom of the microfluidic channel. 展开更多
关键词 shallow Y-shaped microfluidic channel dynamic biochemical signal non-reversing pulsatile flow nonlinear amplitude-frequency modulation Taylor-Aris disper-sion
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Obstructive sleep apnea-hypopnea syndrome immunological relationship
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作者 Mahmoud Ali Alaa Ramadan Salim Surani 《World Journal of Clinical Cases》 SCIE 2024年第27期6011-6014,共4页
Obstructive sleep apnea-hypopnea syndrome(OSAHS)is a complex disorder cha-racterized by symptoms resulting from intermittent hypoxia and hypopnea,with research indicating a crucial role of immune system dysregulation ... Obstructive sleep apnea-hypopnea syndrome(OSAHS)is a complex disorder cha-racterized by symptoms resulting from intermittent hypoxia and hypopnea,with research indicating a crucial role of immune system dysregulation and genetic variations in its pathogenesis.A recent Zhao et al study utilizes Mendelian ran-domization analysis to explore the causal relationship between immune cell characteristics and OSAHS.The study identifies specific lymphocyte subsets as-sociated with OSAHS,providing valuable insights into the disease's pathophy-siology and potential targets for therapeutic intervention.The findings underscore the significance of genetic and immunological factors in sleep disorders,offering a fresh perspective on OSAHS's complexities.Compared to existing literature,Zhao et al's study stands out for its focus on genetic markers and specific immune responses associated with OSAHS,expanding upon previous research primarily centered on systemic inflammation.In conclusion,the study represents a signi-ficant advancement in the field,shedding light on the causal role of immune cells in OSAHS and paving the way for future research and targeted treatments. 展开更多
关键词 Obstructive sleep apnea Mendelian randomization Lymphocyte charac-teristics IMMUNOLOGY Obstructive sleep apnea-hypopnea syndrome
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Vibration isolation performance analysis of a bilateral supported bio-inspired anti-vibration control system
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作者 Shihua ZHOU Dongsheng ZHANG +1 位作者 Bowen HOU Zhaohui REN 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI CSCD 2023年第5期759-772,共14页
To achieve better anti-vibration performance in a low frequency region and expand the range of vibration isolation,a bilateral supported bio-inspired anti-vibration(BBAV)structure composed of purely linear elements is... To achieve better anti-vibration performance in a low frequency region and expand the range of vibration isolation,a bilateral supported bio-inspired anti-vibration(BBAV)structure composed of purely linear elements is proposed,inspired by the motion form of bird legs and the nonlinear extension and compression of muscles and tendons.The kinematic relations and nonlinear dynamic model considering vertical and rotational vibrations are established.The loading capacity and equivalent stiffness are investigated with key parameters.The amplitude-frequency characteristics and force transmissibility are used to evaluate the stability and anti-vibration performance with the effects of the excitation amplitude,rod length,installation angle,and spring stiffness.The results show that the loading requirements and resonant characteristics of the BBAV structure are adjustable,and superior vibration isolation performance can be achieved readily by tuning the parameters.The X-shaped vibration structure is sensitive to the spring stiffness,which exhibits a wider vibration isolation bandwidth with smaller spring stiffness.Besides,depending on the parameters,the nonlinear behavior of the BBAV system can be interconverted between the softening type and the hardening type.The theoretical analysis in this study demonstrates the advantages and effectiveness of the vibration isolation structure. 展开更多
关键词 bio-inspired X-shaped structure anti-vibration performance force transmissibility loading capacity amplitude-frequency curve
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Impact Damage Identification of Aluminum Alloy Reinforced Plate Based on GWO-ELM Algorithm
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作者 Wei Li Benjian Zou +4 位作者 Yuxiang Luo Ning Yang Faye Zhang Mingshun Jiang Lei Jia 《Structural Durability & Health Monitoring》 EI 2023年第6期485-500,共16页
As a critical structure of aerospace equipment,aluminum alloy stiffened plate will influence the stability of spacecraft in orbit and the normal operation of the system.In this study,a GWO-ELM algorithm-based impact d... As a critical structure of aerospace equipment,aluminum alloy stiffened plate will influence the stability of spacecraft in orbit and the normal operation of the system.In this study,a GWO-ELM algorithm-based impact damage identification method is proposed for aluminum alloy stiffened panels to monitor and evaluate the damage condition of such stiffened panels of spacecraft.Firstly,together with numerical simulation,the experimental simulation to obtain the damage acoustic emission signals of aluminum alloy reinforced panels is performed,to establish the damage data.Subsequently,the amplitude-frequency characteristics of impact damage signals are extracted and put into an extreme learning machine(ELM)model to identify the impact location and damage degree,and the Gray Wolf Optimization(GWO)algorithm is employed to update the weight parameters of the model.Finally,experiments are conducted on the irregular aluminum alloy stiffened plate with the size of 2200 mm×500 mm×10 mm,the identification accuracy of impact position and damage degree is 98.90% and 99.55% in 68 test areas,respectively.Comparative experiments with ELM and backpropagation neural networks(BPNN)demonstrate that the impact damage identification of aluminum alloy stiffened plate based on GWO-ELM algorithm can serve as an effective way to monitor spacecraft structural damage. 展开更多
关键词 GWO-ELM aluminum alloy stiffened plate damage identification amplitude-frequency characteristic
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Isolation and Biological Characteristics of Bacteriophage of an Antibiotic-resistant Escherchia coli Strain 被引量:1
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作者 李淑芳 邓瑞玲 +3 位作者 张帅领 张智慧 梁垲珊 张继东 《Agricultural Science & Technology》 CAS 2016年第12期2692-2695,2706,共5页
In this study, bacteriophage of an antibiotic-resistant Escherchia coil strain isolated from feces of chicken was isolated. Its host range was determined by the method of spotting sample on monolayer agar, and its lys... In this study, bacteriophage of an antibiotic-resistant Escherchia coil strain isolated from feces of chicken was isolated. Its host range was determined by the method of spotting sample on monolayer agar, and its lysis titer, optimal multiplicity of infection (MOI), temperature tolerance and pH tolerance were determined by the double-layer agar plate method. The results showed that the bacteriophage had a broad host range. The biological assay demonstrated that two strains of E. coil were fully lysed and one strain of E. coil was weakly lysed by the bacteriophage. The lysis titer and MOI of the bacteriophage were 1.20×10^8 PFU/ml and 1, respec- tively. Under the optimum temperature of 40℃, the Jysis titer of the bacteriophage reached 8.90×10^9 PFU/ml; however, the bacteriophage lost its infectivity at the tem- perature of 80℃. In the pH range of 5-11, the lysis titer of the bacteriophage ranged from10^6 to 10^9 PFU/mI. Under the condition of pH 4 and 12, the bacterio- phage was invalid. 展开更多
关键词 BACTERIOPHAGE Escherchia coli Antibiotic resistance Biological charac-teristics
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Nonlinear principal resonance of magneto-electro-elastic thin plate 被引量:2
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作者 薛春霞 任秀娟 《Journal of Measurement Science and Instrumentation》 CAS 2014年第4期93-98,共6页
Considering magneto-electro-elastic thin plate, the von Karman plate theory of large deflection and the geometric nonlinearity, the mathematical model of nonlinear undamped forced vibration is established. Making use ... Considering magneto-electro-elastic thin plate, the von Karman plate theory of large deflection and the geometric nonlinearity, the mathematical model of nonlinear undamped forced vibration is established. Making use of the improved Lindstedt-Poincare (L-P) method, the undamped forced vibration problem is solved, and the amplitude-frequency response equation of thin plate is obtained. Furthermore, the amplitude frequency response curves of system under different condi- tions are obtained by numerical simulation. The results show that the thickness of the plate, mechanical excitation, parame- ter e, pure piezoelectric material of BaTiO3, pure piezomagnetic material of CoFe2 04, different magneto-electro-elastic ma- terials of BaTiO3/CoFe2 04 and Terfenol-D/PZT will have an impact on the system frequency response. The main effects in- volve principal resonance interval, spring stiffness characteristic and amplitude jumping phenomena. 展开更多
关键词 magneto-electro-elastic thin plate improved Lindstedt-Poincare (L-P) method principal resonance amplitude-frequency response curve
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Rock fragmentation mechanisms and an experimental study of drilling tools during high-frequency harmonic vibration 被引量:9
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作者 Li Wei Yan Tie +1 位作者 Li Siqi Zhang Xiaoning 《Petroleum Science》 SCIE CAS CSCD 2013年第2期205-211,共7页
Resonance drilling is a new technology, still at the laboratory stage. It has great potential to improve rock fragmentation efficiency. We analyzed the amplitude-frequency characteristics of steady- state mechanical v... Resonance drilling is a new technology, still at the laboratory stage. It has great potential to improve rock fragmentation efficiency. We analyzed the amplitude-frequency characteristics of steady- state mechanical vibration excited by harmonic vibration in rocks and an apparatus was built to achieve high fi'equency vibration of rock. The influence of rock drillability, rotary speed, excitation frequency, and other parameters on the rate of penetration (ROP) in resonance drilling was analyzed. The results show that the rock drillability decreased with an increase in excitation frequency. When drilling with a large size drill bit, the ROP increased with excitation frequency. The ROP reached a maximum value at the resonant frequency of the rock. Tile ROP of the bit increased linearly with rotary speed when no vibration was applied on the rock and increased approximately exponentially when harmonic vibration was applied. In addition, the resonant frequency of the rock was changing during the process of rock fi'agmentation, so in order to achieve tile desired resonance of the rock, it is necessary to detemaine an appropriate hamlonic vibration excitation frequency. 展开更多
关键词 Resonance drilling high frequency excitation amplitude-frequency characteristics naturalfrequency DRILLABILITY
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Digitalization of inverting filter shaping circuit for nuclear pulse signals 被引量:7
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作者 Huai-Qiang Zhang Hong-Tao Shi +1 位作者 Zhuo-Dai Li Yu-Wen Li 《Nuclear Science and Techniques》 SCIE CAS CSCD 2020年第9期16-24,共9页
In the design of filter shaping circuits for nuclear pulse signals,inverting filter shaping circuits perform better than non-inverting filter shaping circuits.Because these circuits facilitate changing the phase of a ... In the design of filter shaping circuits for nuclear pulse signals,inverting filter shaping circuits perform better than non-inverting filter shaping circuits.Because these circuits facilitate changing the phase of a pulse signal,they are widely used in processing nuclear pulse signals.In this study,the transfer functions of four types of inverting filter shaping circuits,namely the common inverting filter shaping,improved inverting filter shaping,multiple feedback low-pass filter shaping,and third-order multiple feedback low-pass filter shaping,in the Laplacian domain,are derived.We establish the numerical recursive function models and digitalize the four circuits,obtain the transfer functions in the Z domain,and analyze the filter performance and amplitude-frequency response characteristics in the frequency domain.Based on the actual nuclear pulse signal of the Si-PIN detector,we realize four types of inverting digital shaping.The results show that under the same shaping parameters,the common inverting digital shaping has better amplitude extraction characteristics,the third-order multiple feedback low-pass digital shaping has better noise suppression performance,and the multiple feedback digital shaping takes into account both pulse amplitude extraction and noise suppression performance. 展开更多
关键词 Nuclear pulse signal Inverting filter shaping circuit Digital shaping amplitude-frequency response
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Characterization of TGMS Line 33S in Rice
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作者 谢红军 汤国华 +1 位作者 余应弘 吴升高 《Agricultural Science & Technology》 CAS 2015年第4期719-721,共3页
The research expIored morphoIogical characteristics, fertiIity, and tralts re-Iating to outcrossing of 33S which was of good shapes in pIant and Ieaf, with Iow infertiIity temperature, earIy fIowering period, high fIo... The research expIored morphoIogical characteristics, fertiIity, and tralts re-Iating to outcrossing of 33S which was of good shapes in pIant and Ieaf, with Iow infertiIity temperature, earIy fIowering period, high fIowering rate before noon, and good tralts reIating to outcrossing. 展开更多
关键词 Hybrid rice 33S Thermo-sensitive genie male sterility (TGMS) charac-teristics
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Optimal design study of high order FIR digital filters based on neural network algorithm 被引量:2
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作者 Wang Xiaohua & He YigangCollege of Electrical and Information Engineering, Hunan University, Changsha 410082, P. R. China College of Electrical and Information Engineering, Changsha University of Science and Technology,Changsha 410077, P. R. China 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2004年第2期115-119,130,共6页
An optimal design approach of high order FIR digital filter is developed based on the algorithm of neural networks with cosine basis function . The main idea is to minimize the sum of the square errors between the amp... An optimal design approach of high order FIR digital filter is developed based on the algorithm of neural networks with cosine basis function . The main idea is to minimize the sum of the square errors between the amplitude response of the desired FIR filter and that of the designed by training the weights of neural networks, then obtains the impulse response of FIR digital filter . The convergence theorem of the neural networks algorithm is presented and proved, and the optimal design method is introduced by designing four kinds of FIR digital filters , i.e., low-pass, high-pass, bandpass , and band-stop FIR digital filter. The results of the amplitude responses show that attenuation in stop-bands is more than 60 dB with no ripple and pulse existing in pass-bands, and cutoff frequency of passband and stop-band is easily controlled precisely .The presented optimal design approach of high order FIR digital filter is significantly effective. 展开更多
关键词 high order FIR digital filters amplitude-frequency response neural network convergence theorem optimal design.
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A new method for improving the inductively coupled data transmission rate of mooring buoy based on carrier signal frequency selection 被引量:1
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作者 Rong Du Xingfei Li +1 位作者 Shaobo Yang Hongyu Li 《Nanotechnology and Precision Engineering》 EI CAS CSCD 2020年第2期96-103,共8页
In the inductively coupled data transmission system of the mooring buoy, the carrier signal frequency of the transmission channel is limited due to the inherent characteristics of the system, resulting in limited chan... In the inductively coupled data transmission system of the mooring buoy, the carrier signal frequency of the transmission channel is limited due to the inherent characteristics of the system, resulting in limited channel bandwidth. The limited channel bandwidth limits the increase in inductively coupled data transmission rate.In order to improve the inductively coupled data transmission rate of mooring buoy as much as possible without damaging the data transmission performance, a new method was proposed in this paper. The method is proposed to improve the data transmission rate by selecting the appropriate carrier signal frequencies based on the principle of maximizing the amplitude value of amplitude-frequency characteristic curve of the system. Research has been done according to this method as follows. Firstly, according to the inductively coupled transmission mooring buoy structure, the inductively coupled data transmission circuit model was established. The binary frequency shift keying(2FSK) digital signal modulation mode was selected. Through theoretical analysis, the relation between the carrier signal frequency and the data transmission performance, the relation between the carrier signal frequency and the 2FSK signal bandwidth were obtained. Secondly, the performance and the bandwidth of the signal transmission were studied for the inherent characteristics of the actual inductively coupled data transmission system. The amplitude-frequency characteristic of the system was analyzed by experiments. By selecting the appropriate carrier signal frequency parameters, an excellent data transmission performance was guaranteed and a large 2FSK signal bandwidth was obtained. Finally, an inductively coupled data transmission rate optimization experiment and a bit error rate analysis experiment were designed and carried out. The results show that the high-speed and reliable data transmission of the system was realized and the rate can reach 100 kbps. 展开更多
关键词 Mooring buoy Inherent characteristics Inductively coupled data transmission rate Carrier signal frequency Data transmission performance amplitude-frequency characteristic
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Pendulum-type laser strainmeter
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作者 Grigory Ivanovich Dolgikh 《Earthquake Science》 CSCD 2015年第4期311-317,共7页
Constructive disposition principles of the basic optical units of Michelson interferometers are used in making one-coordinate laser strainmeters of unequal-arm type. The fundamental advantages of pendulurn-type laser ... Constructive disposition principles of the basic optical units of Michelson interferometers are used in making one-coordinate laser strainmeters of unequal-arm type. The fundamental advantages of pendulurn-type laser strainmeter more than classical-type laser strainmeter are displayed. 展开更多
关键词 amplitude-frequency characteristic Classical-type laser strainmeter Elastic wave INFRASOUND Pendulum-type laser strainmeter
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Thin-interbedded reservoirs prediction based on seismic sedimentology
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作者 NI Changkuan SU Mingjun +2 位作者 YUAN Cheng LIU Huaqing CUI Xiangli 《Petroleum Exploration and Development》 CSCD 2022年第4期851-863,共13页
Interference of thin-interbedded layers in seismic reflections has great negative impact on thin-interbedded reservoirs prediction.To deal with this,two novel methods are proposed that can predict the thin-interbedded... Interference of thin-interbedded layers in seismic reflections has great negative impact on thin-interbedded reservoirs prediction.To deal with this,two novel methods are proposed that can predict the thin-interbedded reservoirs distribution through strata slices by suppressing the interference of adjacent layer with the help of seismic sedimentology.The plane distribution of single sand bodies in thin-interbedded reservoirs can be clarified.(1)The minimum interference frequency slicing method,uses the amplitude-frequency attribute estimated by wavelet transform to find a constant seismic frequency with the minimum influence on the stratal slice of target layer,and then an optimal slice corresponding the constant frequency mentioned above can be obtained.(2)The superimposed slicing method can calculate multiple interference coefficients of reservoir and adjacent layers of target geological body,and obtain superimposed slice by weighted stacking the multiple stratal slices of neighboring layers and target layer.The two proposed methods were used to predict the distribution of the target oil layers of 6 m thick in three sets of thin-interbedded reservoirs of Triassic Kelamayi Formation in the Fengnan area of Junggar Basin,Northwestern China.A comparison with drilling data and conventional stratal slices shows that the two methods can predict the distribution of single sand bodies in thin-interbedded reservoirs more accurately. 展开更多
关键词 seismic sedimentology thin-interbedded reservoir stratal slice amplitude-frequency spectrum Triassic Kelamayi Formation Junggar Basin
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Nonlinear free vibration of reticulated shallow spherical shells taking into account transverse shear deformation
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作者 Rong WANG Guohua NIE 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI CSCD 2018年第12期1825-1836,共12页
This paper deals with nonlinear free vibration of reticulated shallow spherical shells taking into account the effect of transverse shear deformation. The shell is formed by beam members placed in two orthogonal direc... This paper deals with nonlinear free vibration of reticulated shallow spherical shells taking into account the effect of transverse shear deformation. The shell is formed by beam members placed in two orthogonal directions. The nondimensional fundamental governing equations in terms of the deflection, rotational angle, and force function are presented, and the solution for the nonlinear free frequency is derived by using the asymptotic iteration method. The asymptotic solution can be used readily to perform the parameter analysis of such space structures with numerous geometrical and material parameters. Numerical examples are given to illustrate the characteristic amplitudefrequency relation and softening and hardening nonlinear behaviors as well as the effect of transverse shear on the linear and nonlinear frequencies of reticulated shells and plates. 展开更多
关键词 nonlinear free vibration reticulated shallow spherical shell transverse shear effect asymptotical iteration method amplitude-frequency relation
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Disk Bimorph-Type Piezoelectric Energy Harvester
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作者 V. Tsaplev R. Konovalov K. Abbakumov 《Journal of Power and Energy Engineering》 2015年第4期63-68,共6页
The study of the experimental investigation of a disk-type piezoelectric energy harvester presented. The harvester contains disk bimorph piezoceramic element of the umbrella form and contains two disk PZT plates. The ... The study of the experimental investigation of a disk-type piezoelectric energy harvester presented. The harvester contains disk bimorph piezoceramic element of the umbrella form and contains two disk PZT plates. The element is excited at the base point at its center. The element is supplied by a loading ring mass to decrease its resonance frequency. The dependences of the vibration displacement along the radii of the bimorph and the ring mass from the frequency of excitation are presented and the output voltage frequency response is also presented as well. The idle mode and the load duty are investigated. The value of the internal resistance of the harvester is obtained using the load characteristic. The piezoelectric specific power is estimated experimentally. 展开更多
关键词 PIEZOELECTRIC Energy HARVESTER UMBRELLA BIMORPH Plate amplitude-frequency Characteristic FLEXURAL Vibration Specific Power Output Voltage
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Developments of parabolic equation method in the period of 2000–2016 被引量:2
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作者 徐传秀 唐骏 +2 位作者 朴胜春 刘佳琪 张士钊 《Chinese Physics B》 SCIE EI CAS CSCD 2016年第12期106-117,共12页
Parabolic equation (PE) method is an efficient tool for modelling underwater sound propagation, particularly for problems involving range dependence. Since the PE method was first introduced into the field of underw... Parabolic equation (PE) method is an efficient tool for modelling underwater sound propagation, particularly for problems involving range dependence. Since the PE method was first introduced into the field of underwater acoustics, it has been about 40 years, during which contributions to extending its capability has been continuously made. The most recent review paper surveyed the contributions made before 1999. In the period of 2000-2016, the development of PE method basically focuses on seismo-acoustic problems, three-dimensional problems, and realistic applications. In this paper, a review covering the contribution from 2000 to 2016 is given, and what should be done in future work is also discussed. 展开更多
关键词 parabolic equation method underwater sound propagation seismo-acoustic transmission charac-teristics modelling three-dimensional problems
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Dynamic test methods for natural frequency of footbridge
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作者 王彩锋 高世桥 金磊 《Journal of Measurement Science and Instrumentation》 CAS 2013年第3期218-222,共5页
Using environmental random vibration as the excitation,traditional accelerometer method,non-contact video method and non-contact laser method were employed to determine the natural frequency of Kunyu River footbridge.... Using environmental random vibration as the excitation,traditional accelerometer method,non-contact video method and non-contact laser method were employed to determine the natural frequency of Kunyu River footbridge.All the results of these three methods are close to 2.70 Hz,which are concordant with each other and hence credible. 展开更多
关键词 test method NON-CONTACT natural frequency amplitude-frequency curveCLC number:TU997 Document code:AArticle ID:1674-8042(2013)03-0218-05
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Electrical characteristics of a fractional-order 3×n Fan network
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作者 Zhi-Zhong Tan Xin Wang 《Communications in Theoretical Physics》 SCIE CAS CSCD 2024年第4期176-187,共12页
In this article a new achievement of fractional-order 3×n Fan networks is presented.In the first step,the RT-I method is used to derive the general formulae of the equivalent impedance of fractional-order 3×... In this article a new achievement of fractional-order 3×n Fan networks is presented.In the first step,the RT-I method is used to derive the general formulae of the equivalent impedance of fractional-order 3×n Fan networks.In the second part,the effects of five system parameters(L,C,n,α and β)on amplitude-frequency and phase-frequency characteristics are analyzed.At the same time,the amplitude-frequency and phase-frequency characteristics of the fractional order 3×n Fan network are revealed by Matlab drawing.This work has important theoretical and practical significance for resistor network models in the field of natural science and engineering technology. 展开更多
关键词 fractional-order circuit amplitude-frequency characteristics phase-frequency characteristics RT-V theory
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Multi–physical-field characteristics modeling and structure optimization for kW-level ultra-high-speed PM motors with integrated support system
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作者 Qixing GAO Xiaolin WANG Yan ZHANG 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 2023年第4期455-467,共13页
In the aerospace industry,the low-mass ultra-high-speed flywheel system play a critical role.In this paper,a kW-level Ultra-High Speed Permanent Magnet Synchronous Motor(UHSPMSM)as the core component of flywheel syste... In the aerospace industry,the low-mass ultra-high-speed flywheel system play a critical role.In this paper,a kW-level Ultra-High Speed Permanent Magnet Synchronous Motor(UHSPMSM)as the core component of flywheel system is proposed and analyzed with consideration of multiple physical fields,including electromagnetic characteristics,mechanical strength and rotor dynamics.The integrated support structure is put forward to improve rotation accuracy and operation stability of the UHSPMSM.Further,influence of the integrated support structure on critical speed is explored,and the key parameters such as support position and support stiffness are designed.Moreover,the rotor strength is analyzed by analytical model developed of rotor stress that can deal with multiple boundary types.Material and thickness of the sleeve are optimized,and range of interference value is accurately limited based on four extreme operating conditions.The 3-D Finite Element Model(FEM)is used to validate the strength characteristics and stress distribu-tion of rotor.A 1.5 kW-150000 r/min UHSPMSM with integrated support system is manufactured and tested.The feasibility of UHSPMSM proposed and the accuracy of analysis method are verified through electromagnetic,temperature rise and vibration characteristics test.The machine prototype realizes the load operation at rated speed and the multi-physical-field characteristics achieve the design specification. 展开更多
关键词 Flywheel energy storage Integrated support system Multi–physical-field charac-teristics Mechanical strength Rotor dynamics Ultra-high-speed motor
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Kinetic modeling of multiphase fow based on simplified Enskog equation 被引量:4
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作者 Yu-Dong Zhang Ai-Guo Xu +2 位作者 Jing-Jiang Qiu Hong-Tao Wei Zung Hang Wei 《Frontiers of physics》 SCIE CSCD 2020年第6期133-145,共13页
A new kinetic model for multiphase flow was presented under the framework of the discrete Boltzmann method(DBM).Significantly different from the previous DBM,a bottom-p approach was adopted in this model.The effects o... A new kinetic model for multiphase flow was presented under the framework of the discrete Boltzmann method(DBM).Significantly different from the previous DBM,a bottom-p approach was adopted in this model.The effects of molecular size and repulsion potential were described by the Enskog collision model;the attraction potential was obtained through the mean field approximation method.The molecular interactions,which result in the non-ideal equation of state and surface tension,were directly introduced as an external force term.Several typical benchmark problems,including Couette flow,two-phase coexistence curve,the Laplace law,phase separation,and the collision of two droplets,were simulated to verify the model.Especially,for two types of droplet collisions,the strengths of two non-equilibrium ffcts,D*2 and D*3,defined through the second and third order non-conserved kinetic moments of(f-feq),are comparatively investigated,where f(feq)is the(equilibrium)distribution function.It is interesting to find that during the collision process,D*2is always significantly larger than D*3,D*2 can be used to identify the different stages of the collision process and to distinguish different types of collisions.The modeling method can be directly extended to a higher.order model for the case where the non-equilibrium pffect is strong,and the linear constitutive law of viscous stress is no longer valid. 展开更多
关键词 multiphase flow discrete Boltzmann method Enskog equation non-equilibrium charac-teristics
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