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小学生时代（大嘴英语） 2024年第12期 26-27页

作者： Minnie 不详

两人三足比赛(three-legged race)即将开赛,可牛哥搭档的腿却受伤了。浣熊自告奋勇上场,和牛哥并肩作战。

关键词： leg race 搭档

Improving Kinematic Flexibility and Walking Performance of a Six-legged Robot by Rationally Designing leg Morphology

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Journal of Bionic Engineering 2019年第4期16卷 608-620页

作者： Jie Chen Zhongchao Liang Yanhe Zhu Jie Zhao School of Mechanical Engineering and Automation Northeastern UniversityShenyang 110819China State Key Laboratory of Robotics and System Harbin Institute of TechnologyHarbin 150001China

This paper explores the design of leg morphology in a six-legged *** by nature,where animals have different leg morphology,we examined how the difference in leg morphology influences behaviors of the *** this end,a systematic search was conducted by scanning over the parameter space consisting of default angles of leg joints of the six-legged robot,with two main objectives:to maximize the kinematic flexibility and walking performance of the *** show that(1)to have a high kinematic flexibility with both the torso and swing legs,the femur segment should tilt downwards by 5°-10°and the tibia segment should be vertically downwards or with a slight inward tilt;(2)to achieve relatively energy-efficient and steady walking,the tibia segment should be approximately vertically downwards,with the femur segment tilting upwards to lower the torso *** results of this study suggest that behaviors of legged robots can be passively enhanced by careful mechanical design choices,thereby leading to more competent legged machines.

关键词： six-legged robot leg morphology kinematic flexibility walking performance

Fuzzy-GA PID controller with incomplete derivation and its application to intelligent bionic artificial leg

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Journal of Central South University of Technology 2003年第3期10卷 237-243页

作者：谭冠政李安平 School of Information Science and Engineering Central South University Changsha 410083 China

An optimal PID controller with incomplete derivation is proposed based on fuzzy inference and the geneticalgorithm, which is called the fuzzy-GA PID controller with incomplete derivation. It consists of the off-line part andthe on-line part. In the off-line part, by taking the overshoot, rise time, and settling time of system unit step re-sponse as the performance indexes and by using the genetic algorithm, a group of optimal PID parameters K*p , Ti* ,and Tj are obtained, which are used as the initial values for the on-line tuning of PID parameters. In the on-linepart, based on K; , Ti* , and T*d and according to the current system error e and its time derivative, a dedicatedprogram is written, which is used to optimize and adjust the PID parameters on line through a fuzzy inference mech-anism to ensure that the system response has optimal dynamic and steady-state performance. The controller has beenused to control the D. C. motor of the intelligent bionic artificial leg designed by the authors. The result of computersimulation shows that this kind of optimal PID controller has excellent control performance and robust performance.

关键词： fuzzy inference genetic algorithm fuzzy-GA PID controller incomplete derivation off-line on-line intelligent bionic artificial leg

leg edema and painful gait in a Western African due to dracunculiasis:A case report

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Asian Pacific Journal of Tropical Medicine 2009年第2期2卷 72-73页

作者： Yann A.Meunier Stanford Health Improvement Program Stanford School of Medicine1070 Arastradero RoadRm 3C03GPalo AltoCa 94304-1334

We present the case of a 28 year old man from Mali who came to consultation for " lower limb edema and painful gait".The diagnosis of dracunculiasis was established by the suggestive symptomatology and the notion of a... 详细信息

关键词： leg edema Painful gait Dracunculiasis Mali

Vortex-Induced Vibration of a Tension leg Platform Tendon:Multi-Mode Limit Cycle Oscillations

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Journal of Marine Science and Application 2017年第4期16卷 458-464页

作者： Nabanita Datta Department of Ocean Engineering and Naval Architecture Indian Institute of Technology Kharagpur - 721302 India

This paper studies the application of mathematical models to analyze the vortex-induced vibrations of the tendons of a given TLP along the Indian coastline, by using an analytical approach, using MATLAB. The tendon is subjected to a steady current load, which causes vortex-shedding downstream, leading to cross-flow vibrations. The magnitude of the excitation(lift and drag coefficients) depends on the vortex-shedding frequency. The resulting vibration is studied for possible resonant behavior. The excitation force is quantified empirically, the added mass by potential flow hydrodynamics, and the vibration by normal mode summation method. Non-linear viscous damping of the water is considered. The non-linear oscillations are studied by the phase-plane method, investigating the limit-cycle oscillations. The stable/unstable regions of the dynamic behavior are demarcated. The modal contribution to the total deflection is studied to establish the possibility of resonance of one of the wet modes with the vortex-shedding frequency.

关键词： tension leg platform vortex-induced vibration non-linear damping limit cycle oscillations multi-mode dynamics

Numerical study of fillet weld leg height of sleeve repair welding for in-service pipeline

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China Welding 2018年第1期27卷 32-40页

作者： Qiao Ling Han Tao Zhang Hongjie Wu Qian Bao Liangliang College of Mechanical and Electronic Engineering China University of Petroleum

This paper presents a mechanical calculation and numerical simulation of the fillet weld of sleeve *** mechanical analysis based on the yield criteria is performed to obtain the minimum value of the fillet weld leg height to ensure the strength and loadbearing capacity of the weld. Within the framework of numerical simulation,the parameters of double ellipsoid heat source are determined by fitting method and the simulated molten pool morphology agrees well with the practical weld. Finite element models with various weld leg height are performed to predict the distribution and magnitude of the deformation and stress. The simulation takes into account thermal,metallurgical and mechanical factors,and the maximum value of the fillet weld leg height is obtained based on the magnitude of the deformation and *** mechanical calculation and numerical simulation results show that 1.2-2 times wall thickness is an optimal range of fillet weld leg height. And reasonable parameters of sleeve repair for in-service welding are provided for engineering field,which can improve the service life of the weld and production efficiency.

关键词： fillet weld leg height numerical simulation theoretical calculation stress deformation

An Approximate Method for the Surge Response of the Tension leg Platform

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Journal of Marine Science and Application 2014年第1期13卷 99-104页

作者： Rahim Shoghi Mohammad Reza Tabeshpour Faculty of Civil Engineering Tabriz University Center of Excellence in Hydrodynamics and Dynamics of Marine Vehicles Mechanical Engineering DepartmentSharif University of Technology

The solution for the Duffing equation in a nonlinear vibration problem is studied in this paper. Clearly, in the case of the perturb parameter being a larger value, the traditional perturbation method is no longer valid but the Homotopy Perturbation Method(HPM) is applicable *** is used to solve the weak and strong nonlinear differential equations for finding the perturbed frequency of the response. The obtained frequencies via HPM and the approximate method have good accordance for weak and strong nonlinear differential equations. Additionally, the calculated responses by use of the approximate method are compared with the responses obtained from the Numerical method in the time history of the response and phase *** results represent good accordance between them.

关键词： Duffing equation nonlinear vibration surgeresponse tension leg platform perturbation differentialequations

leg Atherosclerosis in Japanese COPD Patients: Prevalence of Undiagnosed Peripheral Artery Disease and Association between leg Atherosclerosis and Clinical Indices

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Open Journal of Respiratory Diseases 2013年第1期3卷 25-30页

作者： Hirofumi Matsuoka Yusuke Matsumoto Kengo Kimura Midori Koyama Towa Uzu Yasuko Koma Kensuke Fukumitsu Yoshitaka Kasai Nariyasu Nakashima Daiki Masuya Harukazu Yoshimatsu Yujiro Suzuki Department of Respiratory Medicine Shinko Hospital Kobe Japan

Introduction: Several studies have suggested that decreased FEV1 is associated with cardiovascular risk in COPD patients. Objective: To identify the prevalence of undiagnosed peripheral artery disease (PAD) and the relationship between leg atherosclerosis and clinical indices, which predict COPD mortality in Japanese COPD patients. Methods: We performed a cross-sectional study in 51 COPD patients and 51 age-matched, healthy control smokers. We measured ankle-brachial index (ABI) as a marker of atherosclerosis of the legs, pulmonary function, body mass index, modified Medical Research Council (MMRC) dyspnea scale, and smoking pack-years. We also calculated the ADO index (Age, Dyspnea, and Obstruction), an established predictor of mortality in COPD patients. Co-morbidities including diabetes mellitus, hypertension, and hypercholesterolemia were identified from blood laboratory tests and medical records. Results: Five subjects (9.8%) had an ABI 0.9. ABI was significantly lower in the COPD patients than in the healthy control smokers (p 0.05). The prevalence of PAD was marginally higher in COPD patients than in control smokers (p = 0.09), with the prevalence of ABI 1.0 being significantly higher in COPD patients than in control smokers (p = 0.04). In the COPD patients, ABI showed significant correlations with age (p = 0.006), FEV1 (p = 0.004), smoking pack-years (p = 0.047), MMRC dyspnea scale (p = 0.0005), SaO2 (p = 0.001), andADOindex (p 0.001). Multiple linear regression modeling showed the factors associated independently with ABI were age, FEV1, smoking pack-years, MMRC dyspnea scale, and SaO2. Conclusion: The risk of leg atherosclerosis in Japanese COPD patients is higher than in smokers without COPD. leg atherosclerosis in COPD patients is associated with clinical indices that predict COPD mortality.

关键词： COPD Peripheral Artery Disease leg Atherosclerosis Ankle-Brachial Index

leg Length Discrepancy in Cementless Total Hip Arthroplasty

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Surgical Science 2011年第4期2卷 183-187页

作者： Christopher N Peck Karan Malhotra Winston Y Kim Department of Trauma and Orthopaedics Salford Royal Hospital NHS Foundation Trust

The use of cementless total hip arthroplasty (THA) is on the increase. In order to achieve rotational and axial stability larger implants may be required than originally templated for. This could potentially result in a lar-ger leg length inequality. Our objective was to determine whether there is greater inequality in leg length post-operatively in cementless THA as compared to cemented implants. 136 consecutive patients undergoing elective THA between June 2007 and May 2008 were included. Post-operative digital radiographs were ex-amined to determine leg length. Twenty seven patients (20%) underwent a cemented procedure and 109 (80%) a cementless procedure. In the cemented group the mean leg length discrepancy was 7.3 mm (range 19 mm short to 21 mm long). In the cementless group the mean measured leg length discrepancy was 6.3 mm (range 18 mm short to 23 mm long). There was no significant difference between the two groups (P = 0.443). This study shows that with accurate pre-operative templating, both cemented and cementless proce-dures produce comparable and acceptable leg length discrepancies.

关键词： Hip Arthroplasty Cementless leg Length

Effect of lower leg compression during cesarean section on post-spinal hypotension and neonatal hemodynamic parameters: nonrandomized controlled clinical trial

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International Journal of Nursing Sciences 2019年第3期6卷 252-258页

作者： Wafaa Taha Ebrahim Elgzar Hanan Ebrahim Said Heba Abdelfatah Ebrahim Department of Obstetrics and Gynecology Nursing Faculty of Nursing University of Damanhour Egypt Department of Obstetrics and Woman Health Nursing Faculty of Nursing University of Benha Egypt

Objectives: This study aimed to determine the effect of lower leg compression during cesarean section (CS) on post-spinal hypotension (PSH) and neonatal hemodynamic ***: This study is a nonrandomized controlled clinical trial conducted in the cesarean delivery unit of the National Medical institute,Damanhour,*** sample included 120 parturients (60 intervention and 60 control).The researchers developed three tools for data collection: sociodemographic data and reproductive history interview schedule,electronic monitoring of maternal hemodynamic parameters,and neonatal hemodynamic assessment *** parturients received ordinary preoperative *** the intervention group,a long elastic stocking (ordinary pressure 20-30 mmHg,1 mmHg =0.133 kPa) was applied on both legs during cesarean *** control group received the same care without the elastic ***: Systolic blood pressure,diastolic blood pressure,and mean arterial blood pressure were significantly higher in the intervention group throughout the entire operation period except in the last 5 -15 *** rate was significantly lower in the intervention *** 13.3% of the intervention group took ephedrine compared with 45% of the control *** score was higher among neonates of intervention group compared with the control group at 1 *** acidosis was significantly higher in the control group than in the contral ***: Lower leg compression technique can effectively reduce PSH and neonatal acidosis.

关键词： Cesarean section Hemodynamics Hypotension leg Neonatal Stockings,compression