三维地质力学模型试验中光纤传感器的应用研究   总被引：1，自引：0，他引：1  

李仲奎  王爱民 《实验技术与管理》2006,23(12):57-60

近年来，在地下结构三维地质力学模型试验的研究中。多项新技术得到应用和开发，其中也包括采用光纤传感器量测模型材料中的应变和变形，这使模型试验上了一个新台阶。采用光纤传感器量测。对于地质力学模型试验来说还是一项新技术。该文结合在一个大比尺的地质力学模型试验中采用光纤传感器的经验，对它的实际应用及埋设方法做了进一步的探讨和设想。  相似文献   

木防己多糖的组成及其清除活性氧自由基的作用     

杨海东  陈艳梅  刘淑芬  甄攀 《河北北方学院学报(医学版)》2005,22(2):6-8

目的:提取并纯化木防己多糖(AFMP),确定其组成,研究其清除活性氧自由基的作用.方法:利用水提醇沉得到木防己粗多糖,再经DEAE纤维素和聚酰胺纯制.利用Fenton反应研究AFMP清除·OH的作用;利用邻苯三酚自氧化法研究AFMP清除·O2-的作用.结果:纸色谱显示AFMP由葡萄糖和半乳糖组成.AFMP清除·OH的能力较弱;清除·O2-时的效果稍强,IC50为1407.4μg/ml.结论:木防己多糖为首次提取制得,有一定的清除羟自由基和超氧阴离子自由基的作用.  相似文献   

劳伦斯与沈从文乡土情怀之比较     

资云南 《绵阳师范学院学报》2014,(4):20-23

英国作家D.H.劳伦斯与中国作家沈从文都以自己的家乡为背景创作了大批优秀的"乡土作品"。稍事比较,不难看出劳伦斯与沈从文有着截然不同的乡土情怀:劳伦斯以犀利的笔调贬斥家乡习气之庸俗;沈从文以溢美之言赞颂故里民风之淳朴。然而,这种迥然不同的乡土情怀背后,却深藏着两位作家对生命本真回归作为的向往。  相似文献   

Image-based modeling approach in creating 3D morphogenetic reconstruction of Liberty Square in Novi Sad     

Vesna Stojakovic  Bojan Tepavcevic 《Journal of Cultural Heritage》2011,12(1):105-110

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Between-limb differences in running technique induces asymmetric negative joint work during running     

Satoru Hashizume  Hiroaki Hobara  Yoshiyuki Kobayashi 《European Journal of Sport Science》2019,19(6):757-764

Negative work, which is mainly generated by eccentric muscle contraction, has an important influence on the associated muscle damage. Generally, mechanical parameters are determined for one side of a lower extremity on the assumption of negligible between-limb differences. However, between-limb differences in the negative work of lower extremity joints during running remain unclear. This study examines between-limb differences in negative work and associated mechanical parameters during the contact phase of running. Twenty-five young adult males voluntarily participated in this study. Each participant was asked to run on a straight runway at a speed of 3.0?m?s^?1. Negative work, amplitude, duration of negative power, moment, and angular velocity were computed for both sides of the lower extremities. Significant differences were found in negative work between limbs for the hip (18.9?±?11.7%), knee (13.6?±?10.4%), and ankle (11.8?±?8.5%) joints. For the hip joint, asymmetric negative work was attributable to the between-limb difference in the amplitude of negative power owing to a corresponding difference in the moment. The between-limb differences concerning the duration and amplitude of negative power could explain the asymmetric negative work in the knee joint. The asymmetric negative work of the ankle joint was attributable to the between-limb difference in the amplitude and duration of the negative power and the moment. These results indicate that asymmetric negative work was generated in each lower extremity joint; however, the major mechanical parameters corresponding to the negative work are not the same across the joints.  相似文献   

一种机载重轨InSAR高精度三维定位方法     

董小桐  韩春明  岳昔娟  赵迎辉 《中国科学院大学学报》2019,36(6):844-850

在重轨干涉实际测量中,两次飞行航迹难以保持高度重合,飞行高度和姿态不稳定,干涉图像对存在明显不规则的相对形变,难以进行三维定位。通过分析重轨机载InSAR图像对的几何形变和形成原因,提出一种从精准的InSAR成像几何关系出发,通过修正成像参数,实现机载重轨InSAR高精度三维定位的方法。该方法通过引入地面控制点,实现干涉图像对精准的相对定位,生成高精度DEM;并利用高精度DEM,实现机载重轨InSAR高精度三维定位。对比检查点实测结果和定位结果,表明该方法可有效地解决机载重轨InSAR的三维定位困难的问题。  相似文献   

Kinematic analysis of the drag flick in field hockey     

Rony Ibrahim  Gert S. Faber  Jaap H. van Dieën 《Sports biomechanics / International Society of Biomechanics in Sports》2017,16(1):45-57

Attaining high speed of the stick head and consequently of the ball is essential for successful performance of the drag flick in field hockey, but the coordination pattern used to maximise stick head speed is unknown. The kinematics of the drag flick was studied in ten elite hockey players who performed twenty shots each towards a target located 1.5 m high. A 150 Hz active marker motion analysis system was used, alongside two force plates to detect foot touchdown. Angular velocity and contribution to stick endpoint speed of upper body joints were analysed. Repeated measures ANOVA was used to compare timing of onset and peak angular velocities between joints. Participants used a kinematic pattern that was close to a proximal-to-distal sequence. Trunk axial rotation and lateral rotation towards the target, right wrist flexion and left wrist extension were the main contributors to stick endpoint speed. Coaches should emphasise trunk rotations and wrist flexion and extension movements for maximising stick head speed. Given the high level of the participants in this study, the coordination of joints motions, as reported here, can serve as a guideline for drag flick training.  相似文献   

Shoe drop reduction influences the lower limb biomechanics of children tennis players during an open stance forehand: A longitudinal study     

Alexis Herbaut  Emilie Simoneau-Buessinger  Franck Barbier  Christophe Gillet  Maxime Roux  Nils Guéguen 《European Journal of Sport Science》2017,17(10):1261-1269

Compared to traditional tennis shoes, using 0-drop shoes was shown to induce an immediate switch from rear- to forefoot strike pattern to perform an open stance tennis forehand for 30% of children tennis players. The purpose of the study was to examine the long-term effects of a gradual reduction in the shoe drop on the biomechanics of children tennis players performing open stance forehands. Thirty children tennis players participated in 2 laboratory biomechanical test sessions (intermediate: +4 months and final: +8 months) after an inclusion visit where they were randomly assigned to control (CON) or experimental (EXP) group. CON received 12-mm-drop shoes twice, whereas EXP received 8?mm then 4-mm-drop shoes. Strike index indicated that all CON were rearfoot strikers in intermediate and final test sessions. All EXP were rearfoot strikers in intermediate test session, but half the group switched towards a forefoot strike pattern in final test session. This switch resulted in a decreased loading rate of the ground reaction force (?73%, p?=?.005) but increased peak ankle plantarflexors moment (+47%, p?=?.050) and peak ankle power absorption (+107%, p?=?.005) for these participants compared with CON. Biomechanical changes associated with the long-term use of partial minimalist shoes suggest a reduction in heel compressive forces but an increase in Achilles tendon tensile forces.  相似文献   

The De Kretser case: a note on Sri Lankan writing in English     

Pradeep Jeganathan 《Inter-Asia Cultural Studies》2013,14(3):446-451

Abstract

How is the content of a literary canon, or tradition to be configured? What counts as a literary archive? More than 25 years after Edward Said’s Orientalism (1978 Said, W. Edward. 1978. Orientalism, New York: Vintage.  [Google Scholar]), it seems reasonable to assume, that central to such traditions, would be the work of those who live and work in the society that gives rise to it. In this review, such a location of Michele de Kretser’s new novel, The Hamilton Case, is offered, as a caution to metropolitan literary critics who continue to approach Sri Lankan writing in English, as Christopher Columbus approached ‘America’. It is argued that the novel owes much to, and can be read as echoing and elaborating the detective fiction of S.W.R.D. Bandaranaike, who was, also, the fourth Prime Minister of Ceylon (Sri Lanka), 1956–59.  相似文献   

基于DSP TMS320F2812的数字控制系统设计     

陈亚梅 《荆门职业技术学院学报》2007,22(12):42-45

基于TI公司的DSP芯片TMS320F2812,对其外围电路进行设计,实现一个数字控制的硬件系统,并在此基础上进行相应的软件设计,最终实现一个相对完整的数字控制系统。  相似文献