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Evaluation of right ventricular volume and systolic function in normal fetuses using intelligent spatiotemporal image correlation

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World Journal of Clinical Cases 2019年第15期7卷 2003-2012页

作者： jia-Xing Sun ai-Lu Cai Li-Mei Xie Ultrasound Department Shengjing Hospital of China Medical UniversityShenyang 110004Liaoning ProvinceChina Ultrasound Department Roicare Hospital and ClinicsShenyang 110004Liaoning ProvinceChina

BACKGROUND Heart defects are the most common congenital malformations in *** cardiac structure and function abnormalities lead to changes in ventricular *** ventricular volume is an important index for evaluating fetal cardiovascular development,an effective and reliable method for measuring fetal ventricular volume and cardiac function is necessary for accurate ultrasonic diagnosis and effective clinical *** new intelligent spatiotemporal image correlation(iSTIC)technology acquires high-resolution volumetric *** this study,the iSTIC technique was used to measure right ventricular volume and to evaluate right ventricular systolic function to provide a more accurate and convenient evaluation of fetal heart *** To investigate the value of iSTIC in evaluating right ventricular volume and systolic function in normal *** Between October 2014 and September 2015,a total of 123 pregnant women received prenatal ultrasound examinations in our *** technology was used to acquire the entire fetal cardiac volume with off-line analysis using QLAB *** systolic and diastolic phases were defined by opening of the atrioventricular valve and the subsequent closure of the atrioventricular *** volumetric data of the two phases were measured by manual tracking and summation of multiple slices and recording of the right ventricular end-systolic volume and the right ventricular end-diastolic *** data were used to calculate the right stroke volume,the right cardiac output,and the right ejection *** correlations of changes between the above-mentioned indices and gestational age were *** right ventricular volumes of 30 randomly selected cases were measured twice by the same sonographer,and the intraobserver agreement measurements were *** Among the 123 normal fetuses,the mean right ventricular end-diastolic volume increased from 0.99±0.34 mL at 22 wk gestation to 3.69±0.36

关键词： Ultrasonography Fetus Intelligent spatiotemporal image correlation Right ventricular volume Cardiac function

Dimension Splitting Method for the Three Dimensional Rotating Navier-Stokes Equations

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Acta Mathematicae Applicatae Sinica 2012年第3期28卷 417-442页

作者： Kai-tai LI jia-ping YU Feng SHI ai-xiang HUAN College of Sciences Xi'an Jiaotong UniversityXi'an 710049China Laboratory for Engineering and Scientific Computing Shenzhen Institutes of Advanced TechnologyChinese Academy of SciencesShenzhen 518055China

In this paper, we propose a dimensional splitting method for the three dimensional （3D） rotating Navier-Stokes equations. Assume that the domain is a channel bounded by two surfaces and is decomposed by a series of surfaces i into several sub-domains, which are called the layers of the flow. Every interface i between two sub-domains shares the same geometry. After establishing a semi-geodesic coordinate （S-coordinate） system based on i, Navier-Stoke equations in this coordinate can be expressed as the sum of two operators, of which one is called the membrane operator defined on the tangent space on i, another one is called the bending operator taking value in the normal space on i. Then the derivatives of velocity with respect to the normal direction of the surface are approximated by the Euler central difference, and an approximate form of Navier-Stokes equations on the surface i is obtained, which is called the two-dimensional three-component （2D-3C） Navier-Stokes equations on a two dimensional manifold. Solving these equations by alternate iteration, an approximate solution to the original 3D Navier-Stokes equations is obtained. In addition, the proof of the existence of solutions to 2D-3C Navier-Stokes equations is provided, and some approximate methods for solving 2D-3C Navier-Stot4es equations are presented.

关键词： stream layer 2D manifold Navier-Stokes equations dimension splitting method finite elementmethod

Aerodynamic design on high-speed trains

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Acta Mechanica Sinica 2016年第2期32卷 215-232页

作者： San-San Ding Qiang Li ai-Qin Tian jian Du jia-Li Liu School of Mechanical Electronic and Control EngineeringBeijing Jiaotong University CSR Qingdao Sifang Locomotive & Rolling Stock Co. Ltd.

Compared with the traditional train,the operational speed of the high-speed train has largely improved,and thedynamicenvironmentofthetrainhaschangedfromoneof mechanical domination to one of aerodynamic *** aerodynamic problem has become the key technological challenge of high-speed trains and significantl affects the economy,environment,safety,and *** this paper,the relationships among the aerodynamic design principle,aerodynamic performance indexes,and design variables are firs studied,and the research methods of train aerodynamics are proposed,including numerical simulation,a reducedscale test,and a full-scale *** schemes of train aerodynamics involve the optimization design of the streamlined head and the smooth design of the body *** design of the streamlined head includes conception design,project design,numerical simulation,and a reduced-scale *** design of the body surface is mainly used for the key parts,such as electric-current collecting system,wheel truck compartment,and *** aerodynamic design method established in this paper has been successfully applied to various high-speed trains（CRH380A,CRH380 AM,CRH6,CRH2 G,and the Standard electric multiple unit（EMU）） that have met expected design *** research results can provide an effective guideline for the aerodynamic design of high-speed trains.

关键词： High-speed train Aerodynamic design Optimization design Smooth design

Just-in-time parts feeding optimization for assembly lines under travel time uncertainty

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International Journal of Modeling, Simulation, and Scientific Computing 2021年第5期12卷 43-58页

作者： jia-hua Zhang ai-ping Li Xue-mei Liu Department of Mechatronics Wuxi Vocational Institute of Arts and Technology Yixing 214206 P.R.China School of Mechanical Engineering Tongji University Shanghai 201804P.R.China

Just-in-time(JIT)part feeding is adopted by more and more automobile *** on this part feeding policy,vehicles perform their assigned routes cyclically and provide stations with the exact quantity of parts required until the next arrival of the ***,if there are uncertain travel times,a shortage of materials in stations will be *** this paper,the JIT part feeding optimization problem under travel time uncertainty is *** uncertain travel time is represented by the interval number according to the actual *** minimize the largest possible vehicle trip time,the optimization model is developed based on robust *** the model,a route-dependent uncertain parameter is *** this model,the route of each vehicle and the parts load needed to be delivered by the vehicle can be calculated.A hybrid simulated annealing algorithm is designed to solve this *** parts feeding planning for an engine assembly line is taken as an *** the Monte Carlo simulation,the relationship between the line stoppage probability and the uncertain parameter is studied to obtain the final *** effectiveness of the method is demonstrated by this case study.

关键词： Parts logistics travel time uncertainty robust optimization assembly line vehicle routing

Bispectrum Feature Extraction of Gearbox Faults Based on Nonnegative Tucker3 Decomposition with 3D Calculations

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Chinese Journal of Mechanical Engineering 2013年第6期26卷 1182-1193页

作者： WANG Haijun XU Feiyun ZHAO Jun’ai jia Minping HU jianzhong HUANG Peng School of Mechanical Engineering Southeast University

Nonnegative Tucker3 decomposition（NTD） has attracted lots of attentions for its good performance in 3D data array analysis. However, further research is still necessary to solve the problems of overfitting and slow convergence under the anharmonic vibration circumstance occurred in the field of mechanical fault diagnosis. To decompose a large-scale tensor and extract available bispectrum feature, a method of conjugating Choi-Williams kernel function with Gauss-Newton Cartesian product based on nonnegative Tucker3 decomposition（NTD_EDF） is investigated. The complexity of the proposed method is reduced from o（nNlgn） in 3D spaces to o（RiR2nlgn） in 1D vectors due to its low rank form of the Tucker-product convolution. Meanwhile, a simultaneously updating algorithm is given to overcome the overfitting, slow convergence and low efficiency existing in the conventional one-by-one updating algorithm. Furthermore, the technique of spectral phase analysis for quadratic coupling estimation is used to explain the feature spectrum extracted from the gearbox fault data by the proposed method in detail. The simulated and experimental results show that the sparser and more inerratic feature distribution of basis images can be obtained with core tensor by the NTD EDF method compared with the one by the other methods in bispectrum feature extraction, and a legible fault expression can also be performed by power spectral density（PSD） function. Besides, the deviations of successive relative error（DSRE） of NTD_EDF achieves 81.66 dB against 15.17 dB by beta-divergences based on NTD（NTD_Beta） and the time-cost of NTD EDF is only 129.3 s, which is far less than 1 747.9 s by hierarchical alternative least square based on NTD （NTD_HALS）. The NTD_EDF method proposed not only avoids the data overfitting and improves the computation efficiency but also can be used to extract more inerratic and sparser bispectrum features of the gearbox fault.

关键词： nonnegative tucker3 decomposition Tucker-product convolution power spectrum density updating algorithm

Study on the Preparation of Mercaptoacetic Acid-modified Heterophylla Shell and Its Application in Separation and Enrichment of Pb^2＋ in Environmental Samples

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Chemical Research in Chinese Universities 2018年第4期34卷 665-669页

作者： LYU Linlin jiaNG Xlaojun jia Lian ai Tian WU Hang School of Chemical Engineering University of Science and Technology Liaoning Anshan 114051 P. R. China School of Chemistry and Life Science Anshan Normal University Anshan 114005 P. R. China

To increase the adsorption capacity of the Corylus heterophylla Fisch（HS） for Pb2＋, HS was chemically modified using NaOH aqueous solution and 95% ethanol and was labeled as SHS; then SHS was chemically modified using mercaptoacetic acid. The SHS modified with mercaptoacetic acid（MHS） was characterized using FTIR, SEM, and XPS. The results indicated that the --SH group was present on MHS, and after Pb2＋ adsorption, the absorption value of the characteristic peak of the --SH group decreased. The adsorption and desorption properties of this func- tionalized material were investigated as well as the influences of parameters, such as pH value, type of desorption reagent, dosage, flow rate and maximum sample volume. The Pb2~ adsorption of MI-IS reached a maximum with pH〉5. The experimental data of Pb2＋ adsorption using MHS were fitted using the Langmuir isothermal adsorption model, and a maximum adsorption capacity of 61.54 mg/g was obtained. This was much higher than the adsorption capacity of SHS before modification with the thiol group. After adsorption, MHS was desorbed using a 0.2 mol/L HC1 solution, and the percent of desorption was higher than 99%. MHS was used as a solid-phase extractant in the analysis and determination of Pb2＋ content in food and water samples, and the enrichment times achieved 150-fold.

关键词： Corylus heterophylla Fisch Chemical modification Pb Adsorption Solid-phase extraction

Sensitivity and Distance Based Performance Analysis for Batteryless Tags with Transmit Beamforming and Ambient Backscattering

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China Communications 2022年第2期19卷 109-117页

作者： Minzheng jia Chaochao Yao Wei Liu Ruyi Ye Tutun Juhana Bo ai Department of Information Engineering Beijing Polytechnic CollegeBeijing 100042China School of Computer and Information Technology Beijing Jiaotong UniversityBeijing 100044China School of Communication and Information Engineering Xi’an University of Posts and TelecommunicationsXi’an 710121China Chinese National Institute of Standalization Beijing 100088China School of Electrical Engineering and Informatics Institut Teknologi BandungIndonesia State Key Laboratory of Rail Traffic Control and Safety Beijing Jiaotong UniversityBeijing 100044China

Ambient backscatter is a new green technology for Internet of Things(IoT)that utilizes surrounding wireless signals to enable batteryless devices to communicate with other *** battery-free devices first harvest energy from ambient wireless signals and then backscatter the signals for ***,sensitivity and distance are two important parameters for system ***,most existing studies on ambient backscatter communication systems do not consider the impact of the sensitivity of the energy-harvesting nodes and the distances between these *** this paper,we first provide a literature review for ambient communication technology and then take sensitivity and distance as two key parameters and investigate the sensitivity and distance based performance for ambient backscatter communication ***,we establish the mathematical model based on distances between transceivers and backscattering nodes,extract a parameter that can differentiate the direct path and the backscattering path,evaluate the effects of transmit beamforming,design an energy detector for the reader,and analyze the outage probability of energy harvesting at the tag and the bit error rate(BER)at the *** are then provided to corroborate the proposed studies.

关键词： ambient backscatter battery-free tag Internet of Things(IoT) outage probability performance analysis sensitivity transmission distance

g-C3N4/SnS2 Heterostructure： a Promising Water Splitting Photocatalyst

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Chinese Journal of Chemical Physics 2017年第1期30卷 36-42,I0001页

作者： Shao-hua Chen jia-jun Wang Jing Huang qun-xiang Li Hefei National Laboratory for Physical Sciences at the Microscale and Department of Chemical Physics University of Science and Technology of China Hefei 230026 China Tianjin Key Laboratory of Structure and Performance for Functional Molecules Key Laboratory of Inorganic-Organic Hybrid Functional Materials Chemistry Ministry of EducationCollege of Chemistry Tianjin Normal University Tianjin 300387 China School of Materials and Chemical Engineering Anhui Jianzhu University Hefei 230601 China

Graphite-like carbon nitride （g-C3N4） based heterostrutures has attracted intensive attention due to their prominent photocatalytic performance. Here, we explore the g-CaN4/SnS2 coupling effect on the electronic structures and optical absorption of the proposed g-CaN4/SnS2 heterostructure through performing extensive hybrid functional calculations. The obtained geometric structure, band structures, band edge positions and optical absorptions clearly reveal that the g-C3N4 monolayer weakly couples to SnS2 sheet, and forms a typical van der Waals heterojunction. The g-C3N4/SnS2 heterostructure can effectively harvest visible light, and its valence band maximum and conduction band minimum locate in energetically favorable positions for both water oxidation and reduction reactions. Remarkably, the charge transfer from the g-C3N4 monolayer to SnS2 sheet leads to the built-in interface polarized electric field, which is desirable for the photogenerated carrier separation. The built-in interface polarized electric field as well as the nice band edge alignment implys that the g-CaN4/SnS2 heterostructure is a promising g-CaN4 based water splitting photocatalyst with good performance.

关键词： First-principles calculation Coupling effect Optical absorption Band edge alignment Water splitting

Effects of Ribbon Thickness on Structure and Soft Magnetic Properties of a High-Cu-Content FeBCuNb Nanocrystalline Alloy

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Acta Metallurgica Sinica(English Letters) 2022年第2期35卷 235-242页

作者： Li-Cheng Wu Yan-Hui Li Xing-Jie jia ai-Na He Wei Zhang Key Laboratory of Materials Modification by Laser Ionand Electron Beams(Ministry of Education)School of Materials Science and EngineeringDalian University of TechnologyDalian 116024China Zhejiang Province Key Laboratory of Magnetic Materials and Application Technology CAS Key Laboratory of Magnetic Materials and DevicesNingbo Institute of Materials Technology&EngineeringChinese Academy of SciencesNingbo 315201China

The effects of ribbon thickness(t)on the structure and magnetic properties of a Fe_(82.3)B_(13)Cu_(1.7)Nb_(3) alloy in melt-spun and annealed states have been *** the t from 15 to 23μm changes the structure of the melt-spun ribbons from a single amorphous phase to a composite with denseα-Fe nanograins embedded in the amorphous *** grain size(D_(α-Fe))of theα-Fe near the free surface of the ribbon is about 6.7 nm,and it gradually decreases along the cross section toward the wheel-contacted *** increasing the t to 32μm coarsens the D_(α-Fe) near the free surface to 15.2 nm and aggravates the D_(α-Fe) ramp along the cross *** annealing,the ribbon with t=15μm has relatively largeα-Fe grains with D_(α-Fe)>30 nm,while the thicker ribbons possessing the pre-existing nanograins form a finer nanostructure with D_(α-Fe)ains.

关键词： Fe-based nanocrystalline alloy Microstructure Pre-existingα-Fe nanograin Soft magnetic properties Ribbon thickness