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Water Vapor Motion Signal Extraction from FY-2E Longwave Infrared Window Images for Cloud-free Regions:The Temporal Difference Technique 被引量:3
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作者 YANG Lu WANG Zhenhui +2 位作者 CHU Yanli ZHAO Hang TANG Min 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2014年第6期1386-1394,共9页
The aim of this study is to calculate the low-level atmospheric motion vectors (AMVs) in clear areas with FY-2E IR2 window (11.59-12.79 μm) channel imagery,where the traditional cloud motion wind technique fails.... The aim of this study is to calculate the low-level atmospheric motion vectors (AMVs) in clear areas with FY-2E IR2 window (11.59-12.79 μm) channel imagery,where the traditional cloud motion wind technique fails.A new tracer selection procedure,which we call the temporal difference technique,is demonstrated in this paper.This technique makes it possible to infer low-level wind by tracking features in the moisture pattern that appear as brightness temperature (TB) differences between consecutive sequences of 30-min-interval FY-2E IR2 images over cloud-free regions.The TB difference corresponding to a 10% change in water vapor density is computed with the Moderate Resolution Atmospheric Transmission (MODTRAN4) radiative transfer model.The total contribution from each of the 10 layers is analyzed under four typical atmospheric conditions:tropical,midlatitude summer,U.S.standard,and midlatitude winter.The peak level of the water vapor weighting function for the four typical atmospheres is assigned as a specific height to the TB "wind".This technique is valid over cloudfree ocean areas.The proposed algorithm exhibits encouraging statistical results in terms of vector difference (VD),speed bias (BIAS),mean vector difference (MVD),standard deviation (SD),and root-mean-square error (RMSE),when compared with the wind field of NCEP reanalysis data and rawinsonde observations. 展开更多
关键词 atmospheric motion vector clear sky radiative transfer temporal difference technique
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Uniform stable conformal convolutional perfectly matched layer for enlarged cell technique conformal finite-difference time-domain method 被引量:1
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作者 王玥 王建国 陈再高 《Chinese Physics B》 SCIE EI CAS CSCD 2015年第2期128-136,共9页
Based on conformal construction of physical model in a three-dimensional Cartesian grid,an integral-based conformal convolutional perfectly matched layer(CPML) is given for solving the truncation problem of the open... Based on conformal construction of physical model in a three-dimensional Cartesian grid,an integral-based conformal convolutional perfectly matched layer(CPML) is given for solving the truncation problem of the open port when the enlarged cell technique conformal finite-difference time-domain(ECT-CFDTD) method is used to simulate the wave propagation inside a perfect electric conductor(PEC) waveguide.The algorithm has the same numerical stability as the ECT-CFDTD method.For the long-time propagation problems of an evanescent wave in a waveguide,several numerical simulations are performed to analyze the reflection error by sweeping the constitutive parameters of the integral-based conformal CPML.Our numerical results show that the integral-based conformal CPML can be used to efficiently truncate the open port of the waveguide. 展开更多
关键词 enlarged cell technique CONFORMAL finite-difference time-domain convolutional perfectlymatched layer
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旋转坐标系同核NOE差谱 被引量:7
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作者 缪振春 冯锐 +1 位作者 李光玉 杜泽涵 《波谱学杂志》 CAS CSCD 北大核心 1997年第1期83-88,共6页
提出一种测定旋转坐标系NOE差谱的NMR技术.与通常的NOE技术相比,其特点是:应用范围较广,可节省测定时间,NOE信号为纯吸收型,可测定NOE的大小,并且可得到某些谱峰高度重叠,采用通常技术难于测定的有机化合物的NOE谱.
关键词 旋转坐标系 noe差谱 NMR 分子结构 核磁共振
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用2D NMR及NOE差谱研究一个新的紫杉烷二萜化合物 被引量:1
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作者 孔漫 贺文义 程克棣 《波谱学杂志》 CAS CSCD 1996年第1期75-80,共6页
采用多种二维核磁共振技术及NOE差谱来研究一个新的紫杉烷二萜化合物的结构.确定了3个乙酸基和一个丙酰基的取代位置,解决了大部分立体化学问题,对大多数13C及1H的化学位移给予准确归属.
关键词 NMR noe差谱 紫杉烷 抗肿瘤药
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差谱NOE的应用(Ⅱ)
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作者 葛大伦 孔漫 +1 位作者 梁晓天 谢晶曦 《波谱学杂志》 CAS CSCD 1991年第3期253-259,共7页
本文用核磁共振差谱NOE技术研究了三个小分子化合物的甲氧基构象及几个羟基取代香豆素化合物的结构并得出差谱NOE不能考查螯合OH邻位有无取代基的结论。
关键词 差谱noe 香豆素 化合物 NMR
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用NOE差谱和二维核磁共振技术研究3S-取代烷氧基-奎宁环烷的立体化学
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作者 缪振春 高建华 +1 位作者 冯锐 张其揩 《药学学报》 CAS CSCD 北大核心 1989年第3期194-199,共6页
用3S-奎宁环醇与环氧化合物反应,得到化合物(Ⅰ)的二个光学异构体(3S-1)和(3S-2)。它们的生物活性有明显差别。本文采用NOE差谱和二维NMR技术指定了各异构体的~1H和^(13)C信号的归属,确定了它们的溶液态构象,测定了其C-11的绝对构型,并... 用3S-奎宁环醇与环氧化合物反应,得到化合物(Ⅰ)的二个光学异构体(3S-1)和(3S-2)。它们的生物活性有明显差别。本文采用NOE差谱和二维NMR技术指定了各异构体的~1H和^(13)C信号的归属,确定了它们的溶液态构象,测定了其C-11的绝对构型,并且阐明了立体结构与生物活性间的关系。C-11绝对构型的测定结果经X-射线衍射测定进一步得以肯定。 展开更多
关键词 二维核磁共振 noe差谱 抗胆碱物 非对映异构体 绝对构型
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Corrosion Measurements of Reinforcing Steel by Different Electrochemical Techniques 被引量:1
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作者 S.M.Morsy (Metallurgy Dept. Nuclear Research Center, Atomic Energy Authority, Cairo, Egypt) I.Z.Selim (Physical Chemistry Dept., National Research Center, Dokki, Cairo, Egypt)S. H. Tantawi (Building Research Institute, Dokki, Cairo, Egypt) 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 1995年第6期447-451,共5页
Electrochemical techniques of the corrosion measurements of reinforcing steeI in concrete have been evaluated. These techniques include half-cell potential measurements, impressed voltage method, impressed current met... Electrochemical techniques of the corrosion measurements of reinforcing steeI in concrete have been evaluated. These techniques include half-cell potential measurements, impressed voltage method, impressed current method and potentiostatic polarization technique. The results of corrosion behaviour of the steel in both 5%NaCl and 5%MgSO4 show that each electrochemical technique provides some information about the condition of the steel bar or the corrosivity of the environment being evaluated, yet none provides a complete data regarding the corrosion resistance of reinforcing steel in aggressive media 展开更多
关键词 Corrosion Measurements of Reinforcing Steel by Different Electrochemical techniques
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Sex Difference in the Repolarization Currents of Rabbit Ventricular Cells
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作者 阮燕菲 刘念 +2 位作者 周强 李泱 王琳 《Journal of Huazhong University of Science and Technology(Medical Sciences)》 SCIE CAS 2005年第3期260-262,共3页
The current difference between male and female rabbit ventricular myocytes was investigated for elucidating the mechanism of longer QT interval and higher incidence of drug-associated torsade de pointes in female rabb... The current difference between male and female rabbit ventricular myocytes was investigated for elucidating the mechanism of longer QT interval and higher incidence of drug-associated torsade de pointes in female rabbits than in male rabbits. Whole cell patch clamp technique was used to record APD, I_to, I_K,tail, I_K1 and I_Ca,L of myocytes from left ventricular apex. There was no difference in the membrane capacitance between male and female rabbit myocytes. APD_90 was longer in female rabbits (560.4±26.5 ms, n=15) than in male ones (489.0±20.7 ms, n=14), P<0.05. In female rabbit myocytes, I_K,tail, I_to, I_K1 and I_Ca,L were 0.71±0.05 pA/pF (n=17), 8.28±1.03 pA/pF (n=18), 24.5±3.6 pA/pF (n=12) and 9.0±2.3 pA/pF (n=15) respectively. In male rabbit myocytes, they were 0.84±0.07 pA/pF (n=18), 8.60±1.20 pA/pF (n=18), 25.9±4.5 pA/pF (n=14) and 9.3±2.6 pA/pF (n=16) respectively. I_K,tail in female rabbits was significantly lower than that of male rabbits (P<0.05), but there was no difference in I_to, I_K1 and I_Ca,L between male rabbits and female rabbits (P>0.05). The lower I_K,tail of female rabbit myocytes may contribute to the longer repolarization and the higher incidence of drug-associated torsade de pointes. 展开更多
关键词 patch clamp technique ventricular myocytes potassium current calcium current sex difference
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STEREOSTRUCTURAL DETERMINATION OF ADDITION PRODUCTS FROM ISOFURANOGERMACRENE AND MALEIMIDE BY NMR TECHNIQUES
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作者 Xiu Wen HAN Man KONG +5 位作者 Wen Yi HE Chang Fu XU Shi Zhen MAO Xiao Long XU Yan Wu YANG Guo Xi WANG 《Chinese Chemical Letters》 SCIE CAS CSCD 1992年第11期891-894,共4页
The stereostructures of the title compounds were shown to be represented by (A) and (B).
关键词 NMR STEREOSTRUCTURAL DETERMINATION OF ADDITION PRODUCTS FROM ISOFURANOGERMACRENE AND MALEIMIDE BY NMR techniqueS noe
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A Comparative Study of Dispersion Characteristics Determination of a Trapezoidally Corrugated Slow Wave Structure Using Different Techniques
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作者 Md.Ghulam Saber Rakibul Hasan Sagor Md.Ruhul Amin 《Chinese Physics Letters》 SCIE CAS CSCD 2016年第1期132-135,共4页
The linear dispersion relation of a trapezoidally corrugated slow wave structure (TCSWS) is analyzed and presented. The size parameters of the TCSWS are chosen in such a way that they operate in the x-band frequency... The linear dispersion relation of a trapezoidally corrugated slow wave structure (TCSWS) is analyzed and presented. The size parameters of the TCSWS are chosen in such a way that they operate in the x-band frequency range. The dispersion relation is solved by utilizing the Rayleigh-Fourier method by expressing the radial function in terms of the Fourier series. A highly accurate synthetic technique is also applied to determine the complete dispersion characteristics from experimentally measured resonances (cold test). Periodic structures resonate at specific frequencies when the terminals are shorted numerical calculation, synthetic technique and cold appropriately. The dispersion characteristics obtained from test are compared, and an excellent agreement is achieved. 展开更多
关键词 of on A Comparative Study of Dispersion Characteristics Determination of a Trapezoidally Corrugated Slow Wave Structure Using Different techniques in been IS
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Research on Estimation of Time Delay Difference in Passive Locating for Impulse Signal
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作者 徐复 何文翔 +1 位作者 惠俊英 余赟 《Defence Technology(防务技术)》 SCIE EI CAS 2011年第3期167-175,共9页
Analyzed the relation between time delay difference and time delay estimation errors, based on the principles of three-point locating, a reformed threshold method for time delay difference estimation of impulse signal... Analyzed the relation between time delay difference and time delay estimation errors, based on the principles of three-point locating, a reformed threshold method for time delay difference estimation of impulse signals, called as amendment estimation for short, is developed by introducing channel equalization technique to its conventional version, named as direct estimation in this paper, to improve the estimation stability. After inherent relationship between time delay and phase shift of signals is analyzed, an integer period error compensation method utilized the diversities of both contribution share and contribution mode of concerned estimates is proposed under the condition of high precision phase lag estimation. Finally, a cooperative multi-threshold estimation method composed of amendment and direct estimations to process impulse signals with three thresholds is established. In sea trials data tests of passive locating, this method improves the estimation precision of time delay difference efficiently. The experiments verify the theoretical predictions. 展开更多
关键词 information processing technique PASSIVE locating for IMPULSE signal three point positioning time delay difference ESTIMATION amendment ESTIMATION INTEGER period error compensation cooperative MULTI-THRESHOLD ESTIMATION
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Determination of Iron(Ⅱ), Iron(Ⅲ) and Total Iron in Some β -Thalassemia Patients Using Different Analytical Techniques
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作者 Nabil Fakhre Dashty Ali 《Journal of Environmental Science and Engineering(B)》 2013年第5期304-307,共4页
There are many well-known analytical methods for determination of iron(Ⅱ) and iron(Ⅲ). Among these methods: Gravimetric, titrimetric, potentiometric, conductometric and batch and flow-injection spectrophotometr... There are many well-known analytical methods for determination of iron(Ⅱ) and iron(Ⅲ). Among these methods: Gravimetric, titrimetric, potentiometric, conductometric and batch and flow-injection spectrophotometric methods. In present study, two batch spectrophotometric, atomic absorption spectrometric and biolabo kit methods have been used for determination of iron(Ⅱ), iron(Ⅲ) and total iron. The present methods have the advantages of high sensitivity, low cost reagent, low operation cost, simplicity, speed and their applications for determination of iron(Ⅱ) and iron(Ⅲ) in some serum samples of normal human and fl-thalasemia patients in Erbil city. For the first time especially in Erbil city attempts were made to use zero, first and second derivative spectra to identify the serum samples of some β-thallasemia patients from the normal human serum samples due to the appearance and resolution of peaks in both cases. 展开更多
关键词 Determination IRON β-thalassemia patients different analytical techniques.
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Mapping the Dyke Swarms Emplaced within the Different Archean Cratons of the Indian Shield Using Google^(TM) Earth Images and Arc GIS^(TM) Techniques
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作者 Rajesh K.SRIVASTAVA Amiya K.SAMAL Richard E.ERNST 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2016年第S1期64-65,共2页
The Indian shield comprises a number of Archean–Paleoproterozoic cratonic blocks and predominantly Meso–Neoproterozoic mobile belts with Archean protoliths.All these ancient cratons were thought to be integral parts of
关键词 Earth Images and Arc GIS Mapping the Dyke Swarms Emplaced within the Different Archean Cratons of the Indian Shield Using Google techniques Arc TM
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帕罗西汀联合共情技术对不同年龄高血压合并焦虑抑郁患者身心的影响 被引量:1
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作者 王敏 罗彩东 +2 位作者 戴闽 施剑 黄莉莉 《西北药学杂志》 CAS 2024年第4期166-170,共5页
目的观察帕罗西汀联合共情技术对不同年龄高血压合并焦虑抑郁患者身心状态的影响。方法选取高血压合并焦虑抑郁患者120例,根据年龄分为中青年组与老年组,每组60例。2组均采用帕罗西汀联合共情技术干预,比较2组治疗依从性、干预前后血压... 目的观察帕罗西汀联合共情技术对不同年龄高血压合并焦虑抑郁患者身心状态的影响。方法选取高血压合并焦虑抑郁患者120例,根据年龄分为中青年组与老年组,每组60例。2组均采用帕罗西汀联合共情技术干预,比较2组治疗依从性、干预前后血压[收缩压(special boiling point,SBP)、舒张压(diastolic blood pressure,DBP)]、汉密尔顿焦虑量表(Hamilton anxiety scale,HAMA)评分、汉密顿抑郁量表(Hamilton depression scale,HAMD)评分、共情能力、生活质量和满意度。结果中青年组的治疗总依从性(95.00%)与老年组(91.67%)比较差异无统计学意义(P>0.05);与干预前比较,干预后2组的SBP、DBP均显著降低(P<0.05),但组间比较差异无统计学意义(P>0.05);干预后2组的HAMA、HAMD评分均显著降低,且中青年组的HAMA、HAMD评分均低于老年组(P<0.05);干预后2组的共情能力、生活质量评分均显著升高,且中青年组的评分高于老年组(P<0.05);中青年组的满意度(93.33%)与老年组(86.67%)比较差异无统计学意义(P>0.05)。结论帕罗西汀联合共情技术应用于高血压合并焦虑抑郁患者,可促使患者积极配合治疗,有效控制血压,改善患者的焦虑抑郁情绪,提高患者的共情能力及生活质量,且患者满意度良好。中青年患者焦虑抑郁、共情能力及生活质量的改善情况优于老年患者。 展开更多
关键词 帕罗西汀 共情技术 高血压 不同年龄 焦虑 抑郁
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Finite Difference Scheme for Solving Parabolic Partial Differential Equations with Random Variable Input under Mean Square Sense
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作者 M. A. Sohaly W. W. Mohammed 《Journal of Mathematics and System Science》 2016年第7期263-275,共13页
This study deal with seven points finite difference method to find the approximation solutions in the area of mean square calculus solutions for linear random parabolic partial differential equations. Several numerica... This study deal with seven points finite difference method to find the approximation solutions in the area of mean square calculus solutions for linear random parabolic partial differential equations. Several numerical examples are presented to show the ability and efficiency of this method. 展开更多
关键词 Mean Square Convergence Random Partial Differential Equations Finite difference technique.
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黄芩中国主产区栽培技术差异性调查分析 被引量:2
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作者 王晓英 张胜珍 +4 位作者 段英姿 王向东 马艳芝 客绍英 沈玉龙 《林业与生态科学》 2024年第1期34-40,共7页
黄芩是常用的大宗药材,市场需求量大,为了解当前各产区黄芩栽培技术、管理水平、品质和产量的差异,对山西、陕西、甘肃、山东、河北、河南、内蒙古等我国黄芩主产区的生产现状进行调查,发现各主产区的生态环境、栽培方式、施肥技术、病... 黄芩是常用的大宗药材,市场需求量大,为了解当前各产区黄芩栽培技术、管理水平、品质和产量的差异,对山西、陕西、甘肃、山东、河北、河南、内蒙古等我国黄芩主产区的生产现状进行调查,发现各主产区的生态环境、栽培方式、施肥技术、病虫害防治、采收加工等方面均存在一定差异。因此,建议当前应进行黄芩生态适宜性区分析及各产区适宜栽培技术研究,以便形成黄芩高产、优质、高效的栽培技术体系,进一步为黄芩栽培提质增效奠定基础。 展开更多
关键词 黄芩 主产区 栽培技术 差异性
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Growth and Mortality of the Fan Mussel Pinna Bicolor Cultured under Three Different Techniques
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作者 R.S.S.Wu 《中山大学学报论丛》 1995年第3期205-207,共3页
关键词 ANOVA Growth and Mortality of the Fan Mussel Pinna Bicolor Cultured under Three Different techniques
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The Influence of Cultural Differences on Translation
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作者 曾海波 《海外英语》 2013年第6X期158-159,173,共3页
In the field of translation studies, scholars' understanding of translation in its traditional sense; has shifted along with the popularity and prosperous development of cultural studies in the recent years. Trans... In the field of translation studies, scholars' understanding of translation in its traditional sense; has shifted along with the popularity and prosperous development of cultural studies in the recent years. Translation is no longer regarded as merely a cross-linguistic activity but essentially cross-cultural communication. Cultural factors begin to gain more and more attention to translators. Nida even claims that"for truly successful translating, biculturalism is even more important than bilingualism". Therefore, this thesis will focus on analyzing the influence of cultural differences between Chinese and English on the English translation. This thesis firstly discusses embodiments of cultural differences between Chinese and English; after that, it focuses on influences of cultural differences on translation; last but not least, this thesis also suggests some translating techniques. 展开更多
关键词 CULTURAL differenceS TRANSLATION TRANSLATION techn
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不同速度运动状态中竞走运动员下肢动力学特征研究
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作者 张明军 蒋秋艳 +1 位作者 汪红祥 潘玮敏 《西安体育学院学报》 CSSCI 北大核心 2024年第4期533-543,共11页
目的通过对中国竞走学校优秀运动员不同速度运动状态中下肢动力学特征的分析,为优化专项技术动作,减少运动损伤发生,强化竞走后备人才训练及竞技水平提高提供参考依据。方法选取中国竞走学校男、女一级及以上重点运动员各8名。依据目前... 目的通过对中国竞走学校优秀运动员不同速度运动状态中下肢动力学特征的分析,为优化专项技术动作,减少运动损伤发生,强化竞走后备人才训练及竞技水平提高提供参考依据。方法选取中国竞走学校男、女一级及以上重点运动员各8名。依据目前青少年竞走运动员不同速度区间的划分,应用SONY DSC-RX10M4高速摄像机和Kistler三维测力台同步采集运动员中、高速时下肢的地面反作用力、峰值力和下肢各关节反作用力等动力学数据,应用SIMI运动解析软件和Matlab软件进行计算,采用单因素方差分析对不同速度下的数据进行比较。结果男运动员高速和中速相比,足外侧地面反作用力峰值高速大于中速,且具有显著性差异(P<0.05),足内侧、水平方向和垂直方向的峰值力,均无显著性差异(P>0.05),髋、膝、踝关节水平和垂直方向峰值力均增加,其中髋、膝、踝关节水平方向峰值力增加幅度分别为22.9%、17.5%、20%,垂直方向峰值力增加幅度分别为2.0%、8.2%、2.7%;女运动员高速与中速相比,足外侧和水平前方向地面反作用力峰值高速大于中速,且具有显著性差异(P<0.05),足内侧、水平后和垂直方向峰值力均无显著性差异(P>0.05),髋、膝、踝关节水平和垂直方向峰值力均增加,其中髋、膝、踝关节水平方向峰值力增加幅度分别为31.6%、26.8%、41.7%,垂直方向峰值力增加幅度分别为7.9%、12.8%、7.4%。结论竞走运动员不同速度运动状态下,男、女运动员在一个步态周期中的地面反作用力在不同方向均为高速大于中速,且均表现为垂直方向分力值最大,内外方向的分力最小,而水平方向制动力峰值均大于加速力峰值,此结果为日常训练加强足跟着地动作技术规范性,同时增加蹬地力量训练,提高下肢肌肉用力水平提供了有力证据;另一方面,男、女运动员髋、膝、踝各关节水平和垂直方向峰值力高速均大于中速,在足跟着地时膝关节和踝关节垂直方向受力较大,髋关节受力较小,而前脚掌蹬离地面时,髋部水平方向转动明显大于垂直方向摆动力度,因而青少年竞走运动员日常训练中需加强髋、膝、踝关节运动链的协同和补偿作用,准确掌握竞走技术动作的用力特点和顺序,对于提高其技术动作合理性和科学性,减少下肢损伤,提高运动表现和比赛成绩具有重要意义。 展开更多
关键词 不同速度 竞走运动员 动作技术 下肢动力学
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基于广义积分变换法海洋温差能大口径冷水管强迫振动分析
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作者 谭健 张理 +3 位作者 王冲 张玉龙 张玉 段梦兰 《振动与冲击》 EI CSCD 北大核心 2024年第5期41-51,102,共12页
复杂多变的海洋工况将诱发大口径冷水管强迫振动,为探明均布载荷、线性变化的静水压力、集中载荷和周期载荷作用下冷水管振动响应机制。基于Euler-Bernoulli梁理论,建立了管道动力学控制方程,采用广义积分变换法,求解了系统强迫振动的... 复杂多变的海洋工况将诱发大口径冷水管强迫振动,为探明均布载荷、线性变化的静水压力、集中载荷和周期载荷作用下冷水管振动响应机制。基于Euler-Bernoulli梁理论,建立了管道动力学控制方程,采用广义积分变换法,求解了系统强迫振动的解析解,并与同伦摄动法相对比,验证了该方法的高精度和有效性,分析了内流、黏弹性耗散系数、阻尼比和质量比对管道振动特性的影响。结果表明:当内流流速对应的振动频率与固有频率接近时,管道将出现动态失稳。增大黏弹性耗散系数、阻尼比和质量比对横向位移的抑制效果呈现依次递减的规律,改变激振位置和激振频率可显著改变管道横向位移。该研究成果可对冷水管的初期设计提供一定的指导作用。 展开更多
关键词 海洋温差能 大口径冷水管 广义积分变换法(GITT) 强迫振动 参数分析 振动特性
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