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A toroidal SAW gyroscope with focused IDTs for sensitivity enhancement

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Microsystems & Nanoengineering 2024年第2期10卷 47-56页

作者： Lu Tian Haitao Zhao Qiang Shen Honglong Chang Ministry of Education Key Laboratory of Micro and Nano Systems for Aerospace School of Mechanical EngineeringNorthwestern Polytechnical UniversityXi’an710072China

A surface acoustic wave(SAW)gyroscope measures the rate of rotational angular velocity by exploiting a phenomenon known as the SAW gyroscope effect.Such a gyroscope is a great candidate for application in harsh environments because of the simplification of the suspension vibration mechanism necessary for traditional microelectromechanical system(MEMS)gyroscopes.Here,for the first time,we propose a novel toroidal standing-wave-mode SAW gyroscope using focused interdigitated transducers(FIDTs).Unlike traditional SAW gyroscopes that use linear IDTs to generate surface acoustic waves,which cause beam deflection and result in energy dissipation,this study uses FIDTs to concentrate the SAW energy based on structural features,resulting in better focusing performance and increased SAW amplitude.The experimental results reveal that the sensitivity of the structure is 1.51µV/(°/s),and the bias instability is 0.77°/s,which are improved by an order of magnitude compared to those of a traditional SAW gyroscope.Thus,the FIDT component can enhance the performance of the SAW gyroscope,demonstrating its superiority for angular velocity measurements.This work provides new insights into improving the sensitivity and performance of SAW gyroscopes.

关键词： angular deflection gyroscope

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 activation.In these patients,CRT has demonstrated to improve quality of life,promote reverse left ventricular(LV)remodeling,reduce HF hospitalizations,and extend survival.However,despite advancements in our understanding of CRT,a significant number of patients do not respond to this therapy.Several 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 limitations.Ideally,an accurate,simple,and reproducible ECG marker or set of markers would dramatically overcome the current limitations.We 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 lead.Based 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 ms.The 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

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 cases.Proper assessment is crucial in the initial design stages.This study develops equations to predict the existing pile bending moment and deflection produced by adjacent braced excavations.Influential 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 equations.It 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 method.The developed equations were established through a multiple linear regression analysis of the artificial data,using the transformation technique.In addition,the three-dimensional nature of the excavation work was characterized by considering the excavation corner effect,using the plane strain ratio parameter.The 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

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 detectors.However,using metasurfaces to shape light into wide angular range wavefronts with high efficiency,as is typically required in high-contrast microscopy applications,remains a challenge.Here 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 microscopy.Based 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,respectively.The resulting laser beam is collimated out-of-plane but maintains Gaussian divergence in-plane,resulting in a long and narrow illumination area.We show that metagrating-integrated VCSELs of different kinds can be combined to enable rapid switching between dark-field and total internal reflection illumination.Our 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

deflection Compensation Model for Flatness Measuring Roll

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Journal of Iron and Steel Research(International) 2010年第12期17卷 35-37,45页

作者： LIU Jia-wei ZHANG Dian-hua WANG Jun-sheng WANG Peng-fei State Key Laboratory of Rolling and Automation Northeastern University Shenyang 110004 Liaoning China Anshan Iron and Steel Company Anshan 114001 Liaoning China

In flatness measuring system, the flatness measuring signal can be affected by the deflection of flatness measuring roll. The stress on flatness measuring roll was analyzed and a deflection model for the flatness measuring roll was obtained by using the influence function method. The model was developed on the basis of the deformation of flatness measuring roll in roiling process and compensation curve was obtained. The results indicated that the set curve of flatness is in good agreement with the online measured curve of flatness, and good strip flatness can be obtained.

关键词： flatness measuring roll deflection influence function method compensation curve

Experimental-mechanistic analysis of pavement base deflections measured with light weight deflectometer

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Journal of Traffic and Transportation Engineering(English Edition) 2023年第2期10卷 320-330页

作者： Yao Yao Shuo Li Guangyuan Zhao Yi Jiang Shanghai Urban Construction Design and Research Institute(Group)Co.Ltd. Shanghai 200000China Indiana Department of Transportation West LafayetteIN 47906USA Department of Civil and Environmental Engineering University of WaterlooWaterlooON N2L 3G1Canada School of Construction Management Technology Purdue UniversityWest LafayetteIN 47907USA

An extensive experimental-mechanistic study was conducted to reveal the relationship between the light weight deflectometer(LWD)measured deflections and the degree of compaction of pavement base materials.Both laboratory experiments and test pits experiments were performed with different types of pavement base materials.The modulus based maximum allowable LWD deflections under different structural and compaction conditions were developed for the most commonly used pavement base aggregate in Indiana.The maximum allowable deflections are based on the equivalent subgrade modulus and the thickness of the layer to be compacted.It is emphasized that the LWD deflections must be measured as soon as the material is compacted or before the moisture content decreases beyond a specified range.Therefore,the maximum allowable deflections are specified in terms of the difference between the actual moisture content and the optimum moisture content.The maximum allowable deflection values provide a sound basis for compaction quality control using LWD devices.

关键词： Pavement Light weight deflectometer Compaction deflection Moisture content Modulus

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 presented.The Cs2CO3 catalytic ionization seeds were injected into the combustion chamber to obtain gas plasma on a high temperature magneto hydrodynamic(MHD)experiment rig.The plasma jet was deflected under the action of an external magnetic field,resulting in a thrust-vector effect.Particle image velocimetry(PIV)collected two-dimensional images of jet flow field.Through image processing and velocity vector analysis,the jet deflection angle can be obtained quantitatively.At 1800-2500 K,the jet deflection was verified experimentally under the condition of 0.45 T magnetic field strength.The results indicate that the jet deflection angle increases gradually with the increase of gas temperature,and above 2200 K,the jet deflection angle increase obviously.In 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

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：张大鹏程文明王彬 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

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)voltages.In this paper,the longitudinal normal strain performance of the material was investigated using digital image correlation on a micro-scale.The 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 deformations.The validity of the electromechanical model is then justified with the experimental results obtained from Pt-and Ag-IPMC actuators at various excitation voltages.The 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