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angle of Attack between Blood Flow and Mitral Valve Leaflets in Hypertrophic Obstructive Cardiomyopathy: An In Vivo Multipatient CT-based FSI Study

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Computer Modeling in Engineering & Sciences 2018年第8期116卷 115-125页

作者： Long Deng Xueying Huang Heng Zuo Yuan Zheng Chun Yang Yunhu Song Dalin Tang Department of Cardiac Surgery Fuwai HospitalChinese Academy of Medical Sciences and Peking Union Medical CollegeBeijingChina. School of Mathematical Sciences Fujian Provincial Key Laboratory of Mathematical Modeling and High-Performance Scientific ComputationXiamen UniversityXiamenFujianChina. Department of Mathematical Sciences Worcester Polytechnic InstituteMAUSA. School of Mathematical Sciences Sichuan Normal UniversityChengduSichuanChina. China Information Technology Designing&Consulting Institute Co. Ltd.BeijingChina. School of Biological Science&Medical Engineering Southeast UniversityNanjingChina.

The mechanisms of systolic anterior motion(SAM)of the mitral valve in hypertrophic obstructive cardiomyopathy(HOCM)remain *** investigate the angle of attack between blood flow and mitral valve leaflets at pre-SAM time point,patient-specific CT-based computational models were constructed for 5 patients receiving septal myectomy surgery to obtain pre-and post-operative 2D vector flow *** comparisons between pre-and post-operative angles of attack based on 2D vector flow mapping of 5 patients were *** was found that there was no statistically significant difference between pre-and post-operative angles of attack(61.1±t wa o vs.56.2±56.o,p=0.306,n=5).Therefore,we propose that the angle of attack might not play an important role in the initiation of SAM.

关键词： Hypertrophic obstructive cardiomyopathy systolic anterior motion mitralvalve leaflets computational model angle of attack

Enhanced third-harmonic generation by manipulating the twist angle of bilayer graphene

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Light(Science & Applications) 2021年第2期10卷 176-185页

作者： Seongju Ha Nam Hun Park Hyeonkyeong Kim Jiseon Shin Jungseok Choi Sungmin Park Ji-Yun Moon Kwanbyung Chae Jeil Jung Jae-Hyun Lee Youngdong Yoo Ji-Yong Park Kwang Jun Ahn Dong-Il Yeom Department of Energy Systems Research Ajou University206 Worldcup-roYeongtong-guSuwon 16499Republic of Korea Korea Research Institute of Standards and Science Daejeon 34113Republic of Korea Department of Physics University of Seoul163 SiripdaeroDongdaemun-guSeoul 02504Republic of Korea Department of Smart Cities University of Seoul163 SiripdaeroDongdaemun-guSeoul 02504Republic of Korea Department of Materials Science and Engineering Ajou University206 Worldcup-roYeongtong-guSuwon 16499Republic of Korea Department of Chemistry Ajou University206 Worldcup-roYeongtong-guSuwon 16499Republic of Korea Department of Physics Ajou University206 Worldcup-roYeongtong-guSuwon 16499Republic of Korea

Twisted bilayer graphene(tBLG)has received substantial attention in various research fields due to its unconventional physical properties originating from Moire *** electronic band structure in tBLG modified by interlayer interactions enables the emergence of low-energy van Hove singularities in the density of states,allowing the observation of intriguing features such as increased optical conductivity and photocurrent at visible or near-infrared ***,we show that the third-order optical nonlinearity can be considerably modified depending on the stacking angle in *** third-harmonic generation(THG)efficiency is found to significantly increase when the energy gap at the van Hove singularity matches the three-photon resonance of incident *** study on electrically tuneable optical nonlinearity reveals that the gate-controlled THG enhancement varies with the twist angle in tBLG,resulting in a THG enhanced up to 60 times compared to neutral monolayer *** results prove that the twist angle opens up a new way to control and increase the optical *** tBLG,,suggesting rotation-induced tuneable nonlinear optics in stacked two-dimensional material systems.

关键词： twist angle harmonic

In situ calibrated angle between the quantization axis and the propagating direction of the light field for trapping neutral atoms

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Chinese Physics B 2024年第2期33卷 318-323页

作者：郭瑞军何晓东盛诚王坤鹏许鹏刘敏王谨孙晓红曾勇詹明生 Henan Key Laboratory of Laser and Optoelectronic Information National Center for International Joint Research of Electronic Materials and SystemsSchool of Electrical and Information EngineeringZhengzhou UniversityZhengzhou 450001China State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics Innovation Academy for Precision Measurement Science and TechnologyChinese Academy of SciencesWuhan 430071China

The recently developed magic-intensity trapping technique of neutral atoms efficiently mitigates the detrimental effect of light shifts on atomic qubits and substantially enhances the coherence time. This technique relies on applying a bias magnetic field precisely parallel to the wave vector of a circularly polarized trapping laser field. However, due to the presence of the vector light shift experienced by the trapped atoms, it is challenging to precisely define a parallel magnetic field, especially at a low bias magnetic field strength, for the magic-intensity trapping of85Rb qubits. In this work, we present a method to calibrate the angle between the bias magnetic field and the trapping laser field with the compensating magnetic fields in the other two directions orthogonal to the bias magnetic field direction. Experimentally, with a constantdepth trap and a fixed bias magnetic field, we measure the respective resonant frequencies of the atomic qubits in a linearly polarized trap and a circularly polarized one via the conventional microwave Rabi spectra with different compensating magnetic fields and obtain the corresponding total magnetic fields via the respective resonant frequencies using the Breit–Rabi formula. With known total magnetic fields, the angle is a function of the other two compensating magnetic ***, the projection value of the angle on either of the directions orthogonal to the bias magnetic field direction can be reduced to 0(4)° by applying specific compensating magnetic fields. The measurement error is mainly attributed to the fluctuation of atomic temperature. Moreover, it also demonstrates that, even for a small angle, the effect is strong enough to cause large decoherence of Rabi oscillation in a magic-intensity trap. Although the compensation method demonstrated here is explored for the magic-intensity trapping technique, it can be applied to a variety of similar precision measurements with trapped neutral atoms.

关键词： quantization axis trapping laser angle compensating magnetic fields

Analysis of ARMPS2010 database with LaModel and an updated abutment angle equation

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International Journal of Mining Science and Technology 2020年第1期30卷 111-118页

作者： Deniz Tuncay Ihsan Berk Tulu Ted Klemetti Department of Mining Engineering West Virginia UniversityMorgantownWV 26505USA National Institute for Occupational Safety and Health Pittsburgh Mining Research DivisionPittsburghPA 15236USA

The Analysis of Retreat Mining Pillar Stability(ARMPS) program was developed by the National Institute for Occupational Safety and Health(NIOSH) to help the United States coal mining industry to design safe retreat room-and-pillar panels. ARMPS calculates the magnitude of the in-situ and mining-induced loads by using geometrical computations and empirical rules. In particular, the program uses the "abutment angle" concept in calculating the magnitude of the abutment load on pillars adjacent to a gob. In this paper, stress measurements from United States and Australian mines with different overburden geologies with varying hard rock percentages were back analyzed. The results of the analyses indicated that for depths less than 200 m, the ARMPS empirical derivation of a 21° abutment angle was supported by the case histories;however, at depths greater than 200 m, the abutment angle was found to be significantly less than 21°. In this paper, a new equation employing the panel width to overburden depth ratio is constructed for the calculation of accurate abutment angles for deeper mining cases. The new abutment angle equation was tested using both ARMPS2010 and La Model for the entire case history database of ARMPS2010. The new abutment angle equation to estimate the magnitude of the mining-induced loads used together with the La Model program was found to give good classification accuracies compared to ARMPS2010 for deep cover cases.

关键词： Abutment angle ARMPS2010 LaModel ARMPS-LAM Coal mining Pillar stability

DEM parameter calibration of cohesive bulk materials using a simple angle of repose test

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Particuology 2019年第4期17卷 105-115页

作者： Thomas Roessler Andre Katterfeld Chair of Material Handling Institute of Logistics and Material Handling Systems University of Magdeburg Universitatsplatz 239106 Magdeburg Germany

The numerical effort of discrete element method (DEM) simulations results in a general idealisation of DEM models that makes the calibration crucial to obtaining realistic simulation results. The angle of repose test has become a standard test for the calibration of DEM parameters of cohesionless bulk materials and is extensively discussed in the literature. One of the most used test methods is the pull-up test of a hollow cylinder filled with bulk material. This paper presents how this basic pull-up test can also be used for the calibration of DEM parameters of cohesive materials by changing the analysis criteria. In contrast to analysing the static angle of repose, the focus lies on the macroscopic flow behaviour during the lifting of the cylinder. Reproducible phases of flow are identified in experiments: the build-up of a stable bulk material column, the convex bending of the column, and the beginning of collapse of the column. Furthermore, the phases are independent of the size and lifting velocity. The convex bending of the bulk-material column combined with the moment of first collapse are introduced as new measurable calibration criteria. These experimental results of wet sand are used for the calibration of related DEM parameters using a simplified JKR cohesion model. The DEM calibration including an analysis algorithm that fits the experimental flow behaviour and the final selection of the relevant parameters (i.e., sliding friction coefficient, rolling friction coefficient, and cohesion energy density) is presented in detail.

关键词： Discrete element method angle of repose Cohesive bulk material Calibration

Phase angle Control Based Three-phase DVR with Power Factor Correction at Point of Common Coupling

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Journal of Modern Power Systems and Clean Energy 2020年第1期8卷 179-186页

作者： Jian Ye Hoay Beng Gooi Nanyang Technological University 50 Nanyang Avenue639798Singapore

This paper investigates the ability of correcting the power factor at the point of common coupling(PCC)of the source side using dynamic voltage restorer(DVR).By applying the phase angle control(PAC)method,the DVR compensating voltage will be injected with a specific phase angle and magnitude in series with the transmission line,which leads to a power factor angle shift of the resultant load *** a result,the source voltage is always in phase with the source current under different load conditions,which means that the power factor correction is achieved at the PCC of the source side.A laboratorial prototype of the DVR is utilized to verify the proposed control *** experimental results validate that an approximate unity power factor can be maintained at the source side.

关键词： Dynamic voltage restorer(DVR) voltage sag and swell compensation phase angle control(PAC)method power factor correction

Bio-signal based elbow angle and torque simultaneous predictionduring isokinetic contraction

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Science China(Technological Sciences) 2019年第1期62卷 21-30页

作者： ZHOU Yu LIU JingBiao ZENG Jia LI KaiRu LIU HongHai State Key Laboratory of Mechanical System and Vibration School of Mechanical Engineering Shanghai Jiao Tong University School of Computing The University of Portsmouth

It is of great importance to decode motion dynamics of the human limbs such as the joint angle and torque in order to improve the functionality and provide more intuitive control in human-machine collaborative systems. In order to achieve feasible prediction,both the surface electromyography(sEMG) and A-mode ultrasound were applied to detect muscle deformation and motor *** abled subjects were recruited to perform five trails elbow isokinetic flexion and extension, and each trail contained five repetitions, with muscle deformation and s EMG signals recorded simultaneously. The experimental datasets were categorized as:the ultrasound-EMG combined datasets, ultrasound-only datasets and EMG-only datasets. The support vector machine(SVM)regression model was developed for both elbow joint angle and torque prediction, based on the above three kinds of datasets. The root-mean-square error(RMSE) and the correlation coefficients(R) were applied to evaluate the prediction accuracy. The results across all the subjects for different datasets indicated that the combined datasets and the ultrasound datasets were superior to the sEMG datasets both on elbow joint angle and torque prediction, and there were no significant differences between the combined datasets and the ultrasound datasets. It turns out that elbow angle and torque can be reconstructed by A-mode ultrasound, and the significant findings pave the way towards the application of musculature-driven human-machine collaborative systems.

关键词： angle torque surface electromyography (sEMG) ultrasound support vector machine (SVM) regression isokinetic contraction

Color liquid crystal grating based color holographic 3D display system with large viewing angle

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Light(Science & Applications) 2024年第1期13卷 103-112页

作者： Di Wang Yi-Long Li Fan Chu Nan-Nan Li Zhao-Song Li Sin-Doo Lee Zhong-Quan Nie Chao Liu Qiong-Hua Wang School of Instrumentation and Optoelectronic Engineering Beihang UniversityBeijing 100191China State Key Laboratory of Virtual Reality Technology and Systems Beihang UniversityBeijing 100191China Display Technology Research Center Seoul National UniversityGwanak-ro 1Gwanak-guSeoul 08826Republic of Korea Key Lab of Advanced Transducers and Intelligent Control System Ministry of EducationTaiyuan University of TechnologyTaiyuan 030024China

Holographic 3D display is highly desirable for numerous applications ranging from medical treatments to military ***,it is challenging to simultaneously achieve large viewing angle and high-fidelity color reconstruction due to the intractable constraints of existing ***,we conceptually propose and experimentally demonstrate a simple and feasible pathway of using a well-designed color liquid crystal grating to overcome the inevitable chromatic aberration and enlarge the holographic viewing angle,thus enabling large-viewing-angle and color holographic 3D *** use of color liquid crystal grating allows performing secondary diffraction modulation on red,green and blue reproduced images simultaneously and extending the viewing angle in the holographic 3D display *** principle,a chromatic aberration-free hologram generation mechanism in combination with the color liquid crystal grating is proposed to pave the way for on such a superior holographic 3D *** proposed system shows a color viewing angle of~50.12°,which is about 7 times that of the traditional system with a single spatial light *** work presents a paradigm for achieving desirable holographic 3D display,and is expected to provide a new way for the wide application of holographic display.

关键词： holographic angle crystal

SCAG:A Stratified,Clustered,and Growing-Based Algorithm for Soybean Branch angle Extraction and Ideal Plant Architecture Evaluation

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Plant Phenomics 2024年第3期6卷 595-609页

作者： Songyin Zhang Yinmeng Song Ran Ou Yiqiang Liu Shaochen Li Xinlan Lu Shan Xu Yanjun Su Dong Jiang Yanfeng Ding Haifeng Xia Qinghua Guo Jin Wu Jiaoping Zhang Jiao Wang Shichao Jin Plant Phenomics Research Centre Academy for Advanced Interdisciplinary StudiesCollaborative Innovation Centre for Modern Crop Production cosponsored by Province and MinistryState Key Laboratory of Crop Genetics and Germplasm EnhancementNanjing Agricultural UniversityNanjing 210095China National Center for Soybean Improvement Key Laboratory for Biology and Genetic Improvement of Soybean(GeneralMinistry of Agriculture)College of AgricultureNanjing Agricultural UniversityNanjing 210095China Sanya Research Institute of Nanjing Agriculture University Sanya 572024China State Key Laboratory of Vegetation and Environmental Change Institute of BotanyChinese Academy of SciencesBeijing 100093China School of Automation Southeast UniversityNanjing 210096China Institute of Remote Sensing and Geographic Information System School of Earth and Space SciencesPeking UniversityBeijing 100871China Division for Ecology and Biodiversity School of Biological SciencesThe University of Hong KongHong KongChina

Three-dimensional(3D)phenotyping is important for studying plant structure and *** detection and ranging(LiDAR)has gained prominence in 3D plant phenotyping due to its ability to collect 3D point ***,organ-level branch detection remains challenging due to small targets,sparse points,and low signal-to-noise *** addition,extracting biologically relevant angle traits is *** this study,we developed a stratified,clustered,and growing-based algorithm(SCAG)for soybean branch detection and branch angle calculation from LiDAR data,which is heuristic,open-source,and *** achieved high branch detection accuracy(F-score=0.77)and branch angle calculation accuracy(r=0.84)when evaluated on 152 diverse soybean ***,the SCAG outperformed 2 other classic algorithms,the support vector machine(F-score=0.53)and density-based methods(F-score=0.55).Moreover,after applying the SCAG to 405 soybean varieties over 2 consecutive years,we quantified various 3D traits,including canopy width,height,stem length,and average *** data filtering,we identified novel heritable and repeatable traits for evaluating soybean density tolerance potential,such as the ratio of average angle to height and the ratio of average angle to stem length,which showed greater potential than the well-known ratio of canopy width to height *** work demonstrates remarkable advances in 3D phenotyping and plant architecture *** algorithm can be applied to other crops,such as maize and *** dataset,scripts,and software are public,which can further benefit the plant science community by enhancing plant architecture characterization and ideal variety selection.

关键词： architecture evaluation algorithm angle plant branch ideal clustered extraction growing-based