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Experiment of gas plasma plume deflection by magnetic control

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航空动力学报 2020年第3期35卷 581-588页

作者： ZHAO Kai HU Jianbo LU Yongji LI Feng MING Ming SUN Baigang School of Energy and Power Engineering Beijing University of Aeronautics and AstronauticsBeijing 100191China School of Aviation Operations and Services Aviation University of Air ForceChangchun Jilin 130022China Department of Contract Tactics Air Force Command CollegeBeijing 100097China

To investigate the deflection effect of gas plasma plume controlled by magnetic field,a novel experimental scheme was *** Cs2CO3 catalytic ionization seeds were injected into the combustion chamber to obtain gas plasma on a high temperature magneto hydrodynamic(MHD)experiment *** plasma jet was deflected under the action of an external magnetic field,resulting in a thrust-vector *** image velocimetry(PIV)collected two-dimensional images of jet flow *** image processing and velocity vector analysis,the jet deflection angle can be obtained *** 1800-2500 K,the jet deflection was verified experimentally under the condition of 0.45 T magnetic field *** results indicate that the jet deflection angle increases gradually with the increase of gas temperature,and above 2200 K,the jet deflection angle increase *** the process of gas plasma jet,it is feasible to realize the jet deflection controlled by MHD by adding an external magnetic field.

关键词： gas plasma plume deflection magnetic fluid thrust vector particle image velocimetry

Experimental investigation on plasma jet deflection with magnetic fluid control based on PIV measurement

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Plasma Science and Technology 2019年第2期21卷 83-89页

作者： Kai ZHAO Baigang SUN Yongji LU Feng LI Yongbo LIU Xiangbin LIU Kefu WANG School of Energy and Power Engineering Beihang University School of Aviation Operations and Services Aviation University of Air Force Air Force Command College Air Force Harbin Flight Academy

This paper is devoted to experimentally investigating the influence of magnetic field intensity and gas temperature on the plasma jet deflection controlled by magneto hydrodynamics. The catalytic ionization seed CS_2CO_3 is injected into combustion gas by artificial forced ionization to obtain plasma fluid on a high-temperature magnetic fluid experimental platform. The plasma jet was deflected under the effect of an external magnetic field, forming a thrust-vector *** oxide was selected as a tracer particle, and a two-dimensional image of the jet flow field was collected using the particle image velocimetry(PIV) measurement method. Through image processing and velocity vector analysis of the flow field, the value of the jet deflection angle was obtained quantitatively to evaluate the thrust-vector effect. The variation of the jet deflection angle with the magnetic field intensity and gas temperature was studied under different experimental conditions. Experimental results show that the jet deflection angle increased gradually with a rise in gas temperature and then increased substantially when the gas temperature exceeded 2300 K. The jet deflection angle also increased with an increase in magnetic induction intensity. Experiments demonstrate it is feasible to use PIV test technology to study the thrust vector under magnetic control conditions.

关键词： PIV plasma jet deflection MHD image processing

Large nonlinear deflection behavior of IPMC actuators analyzed with an electromechanical model

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Acta Mechanica Sinica 2019年第5期35卷 992-1000页

作者： H.G.Liu K.Bian K.Xiong Faculty of Civil Engineering and Mechanics Jiangsu UniversityZhenjiang 212013China State Key Laboratory of Mechanics and Control of Mechanical Structures Nanjing University of Aeronautics and AstronauticsNanjing 210016China School of Mechanical and Electrical Engineering Guangzhou UniversityGuangzhou 510006China

This study presents an electromechanical engineering model for the analysis of the large deflection curves of ionic polymer-metal composite(IPMC)cantilever actuators under direct current(DC)*** this paper,the longitudinal normal strain performance of the material was investigated using digital image correlation on a *** deflection of the actuator is analytically obtained with the application of an elliptic integration method based on the relationship between strain gradient and excitation voltage,and the minimum excitation voltage is derived based on the assumption that the actuators have small *** validity of the electromechanical model is then justified with the experimental results obtained from Pt-and Ag-IPMC actuators at various excitation *** findings of this study confirm that the introduced electromechanical model can accurately describe the large nonlinear deflection behavior of IPMC actuators.

关键词： Actuator Ionic polymer metal composite Large deflection Electromechanical model

Improved prediction of pile bending moment and deflection due to adjacent braced excavation

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Frontiers of Structural and Civil Engineering 2023年第11期17卷 1739-1759页

作者： Chana PHUTTHANANON Pornkasem JONGPRADIST Duangkamol SIRIRAK Prateep LUEPRASERT Pitthaya JAMSAWANG Construction Innovations and Future Infrastructures Research Center Department of Civil EngineeringFaculty of EngineeringKing Mongkut's University of Technology ThonburiBangkok 10140Thailand Department of Civil Engineering School of EngineeringKing Mongkut's Institute of Technology LadkrabangBangkok 10520Thailand Soil Engineering Research Center Department of Civil EngineeringKing Mongkut's University of Technology North BangkokBangkok10800Thailand

Deep excavations in dense urban areas have caused damage to nearby existing structures in numerous past construction *** assessment is crucial in the initial design *** study develops equations to predict the existing pile bending moment and deflection produced by adjacent braced *** parameters(i.e.,the excavation geometry,diaphragm wall thickness,pile geometry,strength and small-strain stiffness of the soil,and soft clay thickness)were considered and employed in the developed *** is practically unfeasible to obtain measurement data;hence,artificial data for the bending moment and deflection of existing piles were produced from well-calibrated numerical analyses of hypothetical cases,using the three-dimensional finite element *** developed equations were established through a multiple linear regression analysis of the artificial data,using the transformation *** addition,the three-dimensional nature of the excavation work was characterized by considering the excavation corner effect,using the plane strain ratio *** estimation results of the developed equations can provide satisfactory pile bending moment and deflection data and are more accurate than those found in previous studies.

关键词： pile responses excavation prediction deflection bending moments

Variational analysis of mid-span deflection of gantry cranes

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Journal of Central South University 2017年第11期24卷 2705-2716页

作者： ZHANG Da-peng CHENG Wen-ming WANG Bin School of Mechanical and Electronic Engineering Mianyang Teachers’CollegeMianyang 621000China Research Institute of Mechanical Engineering Southwest Jiaotong UniversityChengdu 610031China Brunel University LondonUK

In practical application, it is very important to master the influence of structure parameters on the mid-span deflection quantificationally. For large-span and heavy-duty gantry cranes, the influence of the rigid leg and the soft leg on mid-span deflection has not been considered in the past. In the paper, the mathematical model is established for universal large-span and heavy-duty gantry cranes. The analytical solution for the mid-span deflection of gantry-frame structure girder is derived and obtained based on the variation principle by considering the coupling effect of the bending moments of girder and legs, the axial force and the secondary bending moments. The relation between the load and the deflection on the mid-span of the gantry-frame structure girder is known. Then, the experimental model is designed according to dimensional analysis method. And experiments were performed on the WEW-600 B type testing machine. Hackling experimental data, the regular of the load and deflection on the girder mid-span is obtained, namely, the deformation of the gantry-frame structure resists the external load to do work. The validity of the nonlinear analytical solution of the girder deflection is verified. Experimental results show that the analytical solution of the gantry-frame structure deflection has much higher calculation accuracy than previous calculation method. This work provides a theoretical basis for the design and inspection of gantry-frame structures.

关键词： gantry crane deflection structural stiffness variational analysis

The Application of Similarity Theory in Designing Large deflection Buckling Spring-Piece

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上海交通大学学报 2004年第z2期38卷 42-47页

作者： Huang Tiequn Jia Shushi Sun Yueming Cheng Yaodong China Institute of Metrology Hangzhou310018 China Zhejiang University Hangzhou310027 China Zhejiang University Hangzhou310027 China Zhejiang University Hangzhou310027 China

Large deflection Buckling Spring-Piece (LDBSP) refers to the deformation of an end-fixed flat spring-piece under normal loadings. Plastic deformation usually appears in *** static characteristic curve is very particular, because within its linear deflection region, the spring constant can be designed to be any value from minus to plus. With its obvious advantages of large liner deflection range, low spring constant, etc., the LDBSP has now been extensively applied to the exciting device, low-frequency shock absorbers and so on. The static characteristic curve of LDBSP belongs to the nonlinear problem of an arch with varying section. Therefore, it is difficult to obtain it theoretically. The formulae for designing LDBSP have not been set up yet. In this study,the authors apply similarity theory to analyze the liner deflection range A and the spring constant K, and derive the relationship of similarity criterion, finally obtain a set of formulae for designing LDBSP by model test and the least square method, which can be applied in engineering *** the research, it is proved that it is unnecessary to keep geometrical similarity of spring-piece shape. This fact extends the application scope of the formulae. The proposed formulae for designing LDBSP thereby can be applied for any dimensions within the range allowed.

关键词： similarity theory similarity criterion dimension model test deflection spring spring constant plastic deformation

High-angle deflection of metagrating-integrated laser emission for high-contrast microscopy

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Light(Science & Applications) 2023年第11期12卷 2434-2442页

作者： Mindaugas Juodėnas Erik Strandberg Alexander Grabowski Johan Gustavsson HanaŠípová-Jungová Anders Larsson Mikael Käll Department of Physics Chalmers University of Technology41296 GothenburgSweden Department of Microtechnology and Nanoscience Chalmers University of Technology41296 GothenburgSweden

Flat metaoptics components are looking to replace classical optics elements and could lead to extremely compact biophotonics devices if integrated with on-chip light sources and ***,using metasurfaces to shape light into wide angular range wavefronts with high efficiency,as is typically required in high-contrast microscopy applications,remains a *** we demonstrate curved GaAs metagratings integrated on vertical-cavity surface-emitting lasers(VCSELs)that enable on-chip illumination in total internal reflection and dark field *** on an unconventional design that circumvents the aspect ratio dependent etching problems in monolithic integration,we demonstrate off-axis emission centred at 60°in air and 63°in glass with>90%and>70%relative deflection efficiency,*** resulting laser beam is collimated out-of-plane but maintains Gaussian divergence in-plane,resulting in a long and narrow illumination *** show that metagrating-integrated VCSELs of different kinds can be combined to enable rapid switching between dark-field and total internal reflection *** approach provides a versatile illumination solution for high-contrast imaging that is compatible with conventional microscopy setups and can be integrated with biophotonics devices,such as portable microscopy,NIR-II range bioimaging,and lab-on-a-chip devices.

关键词： illumination deflection optics

Electrocardiographic markers of cardiac resynchronization therapy response:delayed time to intrinsicoid deflection onset in lateral leads

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Journal of Geriatric Cardiology 2022年第1期19卷 21-30页

作者： Rubén KA Tapia-Orihuela S Michael Gharacholou Samuel J Asirvatham Freddy Del-Carpio Munoz Department of Medicine Universidad Nacional Mayor de San MarcosFacultad de Medicina de San FernandoLimaPeru Department of Cardiovascular Diseases Mayo ClinicJacksonvilleFLUSA Department of Cardiovascular Diseases Mayo ClinicRochesterMNUSA

Cardiac resynchronization therapy(CRT)has emerged as an important intervention for patients with heart failure(HF)with reduced ejection fraction and delayed ventricular *** these patients,CRT has demonstrated to improve quality of life,promote reverse left ventricular(LV)remodeling,reduce HF hospitalizations,and extend ***,despite advancements in our understanding of CRT,a significant number of patients do not respond to this *** invasive and non-invasive parameters have been assessed to predict response to CRT,but the electrocardiogram(ECG)has remained as the prevailing screening method albeit with ***,an accurate,simple,and reproducible ECG marker or set of markers would dramatically overcome the current *** describe the clinical utility of an old ECG parameter that can estimate ventricular activation delay:the onset to intrinsicoid deflection(ID).Based on the concept of direct measurement of ventricular activation time(intrinsic deflection onset),time to ID onset measures on the surface ECG the time that the electrical activation time takes to reach the area subtended by the corresponding surface ECG *** on this principle,the time to ID on the lateral leads can estimate the delay activation to the lateral LV wall and can be used as a predictor for CRT response,particularly in patients with non-specific intraventricular conduction delay or in patients with left bundle branch block and QRS<150 *** aim of this review is to present the current evidence and potential use of this ECG parameter to estimate LV activation and predict CRT response.

关键词： deflection intrinsic synchronization

Analysis on deflection Characteristics of Steel Cable-Stayed Bridge

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Transactions of Nanjing University of Aeronautics and Astronautics 2018年第5期35卷 890-895页

作者： Liu Xiaoling Huang Qiao Ren Yuan Faculty of Maritime and Transportation Ningbo University School of Transportation Southeast University

Various kinds of deflection characteristics on the steel cable-stayed bridge(Nanjing No.3 Yangtze River Bridge)are investigated by different mathematical statistical ***,via Pearson correlation coefficient calculation,it shows good consistency between the adjacent measuring point of side span or middle ***,taking mid-span deflection as an example,the correlation analysis of deflection and temperature is *** are synchronous via cross correlation coefficient calculation but not completely linear and a"hysteresis loop"phenomenon of three stages is *** fitting result on the monitoring data at day time is consistent with the numerical value through the application of unit temperature difference between the cable and girder and the positive temperature gradient of girder in the finite element *** the temperature effect is *** loads effect is obtained from wavelet *** extracted curve can indirectly reflect the change of traffic ***,the structural damage is analyzed through the trend fusion on the deflection,cable force and visual inspection from 2006 to *** conclusions can provide a basis for management departments to carry out special detection.

关键词： steel cable-stayed bridge health monitoring deflection characteristics analysis