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Numerical simulation of axial liquid film cooling in rocket combustor

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航空动力学报 2013年第2期28卷 459-465页

作者： yang Wei SUN Bing ZHENG Li-ming School of Astronautics Beijing University of Aeronautics and Astronautics

Numerical simulation has been done for liquid film cooling in liquid rocket *** species of axial Navier-Stokes equations have been solved for liquid-film / hot-gas flow field,and k-εequations have been used for compressible turbulent *** results of the model agree well with the results of software *** results show that :(1) Liquid film can decrease the wall heat flux and temperature effectively,and the cold border area formed by the film covers the whole combustor and nozzle wall.(2) The turbulent viscosity is higher than the physical viscosity,and its biggest value is in the border area of the convergent area in *** effect of turbulent flow on the whole simulation field can not be ignored.(3) The mass fraction of kerosene at the film inlet is 1,but it decreases along the nozzle wall and achieves its lowest value at the ***,the mass fraction of kerosene near the wall is the biggest at any axial location.

关键词： liquid rocket engine liquid film cooling heat flux numerical simulation turbulent flow

OTT Messages Modeling and Classification Based on Recurrent Neural Networks

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Computers, Materials & Continua 2020年第5期63卷 769-785页

作者： Guangyong yang Jianqiu Zeng Mengke yang Yifei Wei Xiangqing Wang Zulfiqar Hussain Pathan School of Economics&Management Beijing University of Posts and TelecommunicationsBeijing100876China School of Automation Beijing University of Posts and TelecommunicationsBeijing100876China School of Electronic&Engineering Beijing University of Posts and TelecommunicationsBeijing100876China Mehran University of Engineering&Technology JamshoroPakistan

A vast amount of information has been produced in recent years,which brings a huge challenge to information *** better usage of big data is of important theoretical and practical significance for effectively addressing and managing *** this paper,we propose a nine-rectangle-grid information model according to the information value and privacy,and then present information use policies based on the rough set *** neural networks were employed to classify OTT *** content of user interest is effectively incorporated into the classification process during the annotation of OTT messages,ending with a reliable trained classification *** results showed that the proposed method yielded an accurate classification performance and hence can be used for effective distribution and control of OTT messages.

关键词： OTT messages information privacy nine-rectangle-grid hierarchical classification recurrent neural networks

Automatic segmentation of bladder in CT images

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2009年第2期10卷 239-246页

作者： Feng SHI Jie yang Yue-min ZHU Institute of Image Processing and Pattern Recognition Shanghai Jiao Tong University Shanghai 200240 China CREATIS. LNSA of Lyon University of Lyon 1 Villeurbanne France

Segmentation of the bladder in computerized tomography(CT) images is an important step in radiation therapy planning of prostate cancer. We present a new segmentation scheme to automatically delineate the bladder contour in CT images with three major steps. First,we use the mean shift algorithm to obtain a clustered image containing the rough contour of the bladder,which is then extracted in the second step by applying a region-growing algorithm with the initial seed point selected from a line-by-line scanning process. The third step is to refine the bladder contour more accurately using the rolling-ball algorithm. These steps are then extended to segment the bladder volume in a slice-by-slice manner. The obtained results were compared to manual segmentation by radiation oncologists. The average values of sensitivity,specificity,positive predictive value,negative predictive value,and Hausdorff distance are 86.5%,96.3%,90.5%,96.5%,and 2.8 pixels,respectively. The results show that the bladder can be accurately segmented.

关键词： Image segmentation Computerized tomography (CT) Mean shift Bladder Rolling ball

Diagnosis of stator faults in induction motor based on zero sequence voltage after switch-off

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2008年第2期9卷 165-172页

作者： Jia-qiang yang Jin HUANG Tong LIU School of Electrical Engineering Zhejiang University Hangzhou 310027 China

To improve the accuracy of the stator winding fault diagnosis in induction motor,a new diagnostic method based on the Hilbert-Huang transform(HHT)was *** ratio of fundamental zero sequence voltage to positive sequence voltage after switch-off was selected as the stator fault characteristic,which could effectively avoid the influence of the supply unbalance and the load fluctuation,and directly represent the asymmetry in the *** the empirical mode decomposition(EMD)based on HHT,the zero sequence voltage after switch-off was decomposed and the fundamental component was ***,the fault characteristic can be *** results on a 4-kW induction motor demonstrate the feasibility and effectiveness of this method.

关键词： Induction motor Stator fault diagnosis Hilbert-Huang transform (HHT) Zero sequence voltage Empirical modedecomposition (EMD)

Effect of emotion management and nursing on patients with painless induced abortion after operation

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World Journal of Psychiatry 2024年第8期14卷 1182-1189页

作者： Jing yang Xiao yang Zhuo-Ya Xiong Gynecological Clinic Wuhan Children’s Hospital(Wuhan Maternal and Child Healthcare Hospital)Tongii Medical CollegeHuazhong University of Science&TechnologyWuhan 430000Hubei ProvinceChina

BACKGROUND With an estimated 121 million abortions following unwanted pregnancies occurring worldwide each year,many countries are now committed to protecting women’s reproductive *** To analyze the impact of emotional management and care on anxiety and contraceptive knowledge mastery in painless induced abortion(IA)*** This study was retrospective analysis of 84 patients with IA at our *** to different nursing methods,the patients were divided into a control group and an observation group,with 42 cases in each *** of pain,rate of postoperative uterine relaxation,surgical bleeding volume,and postoperative bleeding volume at 1 h between the two groups of patients;nursing satisfaction;and mastery of contraceptive knowledge were *** After nursing,Self-Assessment Scale,Depression Self-Assessment Scale,and Hamilton Anxiety Scale scores were 39.18±2.18,30.27±2.64,6.69±2.15,respectively,vs 45.63±2.66,38.61±2.17,13.45±2.12,respectively,with the observation group being lower than the control group(P<0.05).Comparing visual analog scales,the observation group was lower than the control group(4.55±0.22 vs 3.23±0.41;P<0.05).The relaxation rate of the cervix after nursing,surgical bleeding volume,and 1-h postoperative bleeding volumes were 25(59.5),31.72±2.23,and 22.41±1.23,respectively,vs 36(85.7),42.39±3.53,28.51±3.34,respec tively,for the observation group compared to the control *** observation group had a better nursing situation(P<0.05),and higher nursing satisfaction and contraceptive knowledge mastery scores compared to the control group(P<0.05).CONCLUSION The application of emotional management in postoperative care of IA has an ideal effect.

关键词： Emotional management Induced abortion Anxiety Care Contraceptive knowledge

Uncertain Fractional Grey Model Analysis with Optimal H-infinite Control 36

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Uncertain Fractional Grey Model Analysis with Optimal H-infi...

Anti-function solution of uniaxial anisotropic Stoner-Wohlfarth model

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作者： yang yang Xiuqin Wang College of Engineering Bohai University College of Information Science and Technology Bohai University

ISBN: (纸本)9781538629185

Model inaccuracies or parameter uncertainties are unavoidable in the practical control systems, while the uncertain properties could be modeled and estimated by the grey system. Among many grey models, fractional grey model is recently proposed and popularly used in many model analysis and prediction problems. In this paper, the structure uncertainties and external disturbances are considered using the fractional grey model for control problem. When the model of the fractional grey controlled object and its parameters range is known, based on the model properties, it can be also approximated by a high order one, then the satisfactory adaptive ability and robustness can be obtained by the H-infinite optimal control. In the numerical simulation part, the corresponding results demonstrate the effectiveness of the robust fractional grey control algorithm, and it can be used for other grey control and related problems.

关键词： H-infinite control grey system fractional grey model uncertain information

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Chinese Physics B 2022年第4期31卷 78-82页

作者： Kun Zheng Yu Miao Tong Li Shuang-Long yang Li Xi yang yang Dun Zhao De-Sheng Xue Key Laboratory for Magnetism and Magnetic Materials of the Ministry of Education Lanzhou UniversityLanzhou 730000China School of Mathematics and Statistics Lanzhou UniversityLanzhou 730000China

The anti-trigonometric function is used to strictly solve the uniaxial anisotropic Stoner-Wohlfarth(SW) model,which can obtain the relation of the angle α(θ) between the magnetization(the anisotropy field) and the applied magnetic *** this analytic solution,the hysteresis loops of uniaxial anisotropic SW particles magnetized in typical directions could be numerically ***,the hysteresis loops are obtained in randomly distributed SW particle ensembles while ignoring the dipole interaction among them with the analytic ***,the correctness of the analytic solution is verified by the exact solutions of remanence,switching field,and coercivity from the SW *** analytic solution provides an important reference for understanding the magnetizing and magnetization reversal processes of magnetic materials.

关键词： Stoner-Wohlfarth model anti-trigonometric function hysteresis loop

How to detect melting in laser heating diamond anvil cell

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Chinese Physics B 2016年第7期25卷 31-35页

作者：杨留响 Center for High Pressure Science and Technology Advanced Research Shanghai 201203China High Pressure Synergetic Consortium Geophysical LaboratoryCarnegie Institution of WashingtonArgonneIL 60439USA

Research on the melting phenomenon is the most challenging work in the high pressure/temperature field. Until now,large discrepancies still exist in the melting curve of iron, the most interesting and extensively studied element in geoscience research. Here we present a summary about techniques detecting melting in the laser heating diamond anvil cell.

关键词： high pressure laser melting diamond anvil cell

Left-handed properties of a composite structure with metallic wires in a homogeneous Lorentz medium

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International Journal of Minerals,Metallurgy and Materials 2012年第2期19卷 159-164页

作者： yang Bai Fang Xu Li-jie Qiao Key Laboratory of Environmental Fracture(Ministry of Education) University of Science and Technology BeijingBeijing 100083China

The electromagnetic properties of a composite structure with metallic wires in a Lorentz medium were studied. The results show that the electromagnetic properties of the medium host influence the plasma resonance of metallic wires and the left-handed character of the composite. The plasma frequency of metallic wires reduces with the rise of permittivity or permeability of the medium host. Also, the negative permeability of the medium can destroy the wires’ plasma resonance and prevent the realization of left-handed properties. The high loss of medium permittivity or permeability also inhibits the metallic plasma resonance. The negative influence of the media host on the left-handed properties of the composite structure can be effectively reduced by proper structure design, such as introducing a nonmagnetic medium in the host or using an anisotropic medium.

关键词： electromagnetic waves left-handed materials plasma resonance electromagnetic interaction