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1.
It is required to develop micro-machine for inspection and maintenance of defects inside small pipe withdiameter smaller than one inch. Considering the advantages of electromagnetic actuators with simple mechanism,high response, convenience to control and fabricate, we tried to develop a new micro-robot in small pipe based on in-teraction principle of electromagnetic attraction and spring force. This paper describes its structure and design. Thedimension of the prototype is diameter of 15 mm, length of 30 mm and weight of 25 g. It can climb in small pipe ofdiameter of 20 mm with a speed of 6～8 mm/s in horizontal or in vertical situation. 相似文献
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1 Introduction The main advantage of reconfigurable robots is thatthey can change structures and shapes autonomouslyaccording to the external environment or practical taskdemands . This makes themrobust and flexible to suitthe tasks and the environment in order to work well inmany unstructured environments such as aviation,planetary exploration, military reconnaissance andattacks ,rescue ,etc. Many researches have been con-ducted in recent years[1-5],and there has been increa-sing research int… 相似文献
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SUN Lin zhi SUN Ping WANG Cun min QIN Xin jie 《上海大学学报(英文版)》1999,3(4):308-312
１ Ｉｎｔｒｏｄｕｃｔｉｏｎ Ｍｉｌｌｉｍｅｔｅｒｓｉｚｅｍｉｃｒｏｍａｃｈｉｎｅｓｂａｓｅｄｏｎｍｏｄｅｒｎｐｒｅｃｉｓｉｏｎｍａｃｈｉｎｉｎｇｈａｖｅｐｏｔｅｎｔｉａｌａｐｐｌｉｃａｔｉｏｎｉｎｉｎｄｕｓｔｒｙ．Ｓｏｍｅｎａｒｒｏｗｓｐａｃｅｓｏｒｓｍａｌｌａｒｅａｓｎｅｅｄｔｈｅｓｅｍｉｃｒｏｍａｃｈｉｎｅｓｔｏｉｎｓｐｅｃｔａｎｄｒｅｐａｉｒｄｅｆｅｃｔｓ．Ｒｅｓｅａｒｃｈｅｒｓｈａｖｅｗｏｒｋｅｄｏｎｆａｂｒｉｃａｔｉｏｎｏｆｖａｒｉｅｄｖｅｈｉｃｌｅｓｗｉｔｈｗｈｅｅｌｓ,ｍｏｂ… 相似文献
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城市社区体育服务体系发展动力系统是指驱动社区体育服务发展和演化的力量机构系统,具有比较稳定的构成方式和作用规则.城市社区体育服务体系发展动力系统的要素包括经济保障力、政治调控力和文化推动力.经济保障力是城市社区体育服务体系发展的前提,为社区体育服务体系的发展创造条件.政治调控力整合社会资源,控制社区体育服务发展的方向,在社区体育服务体系中起着调控的作用.文化推动力以树立科学的体育价值观规范城市社区体育服务体系的发展方向.三个动力之间必须协调作用,处理好相互之间的关系,形成良性互动,才能使社区体育服务体系发展的速度更快、速率更高、效益更大. 相似文献
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与力学中用物体势能的空间变化率来计算力的方法相似,假定受力物体在受力方向上发生微小的"虚位移",根据不同情况下的电源供给系统的能量、系统增加的电磁场能量、静电场力和磁场力做的功之间的关系,就可方便地求出物体受到的静电场力和磁场力. 相似文献
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对蜜蜂悬停飞行时二维柔性翅气动特性进行了研究．建立了昆虫飞行的4种坐标系,包括地面坐标系、贴体坐标系、固定翼坐标系和柔性翼坐标系,分别表示昆虫的位置、姿态、翅膀运动形式及变形．对4种坐标系间的变换进行了研究,并指出在二维刚性翅研究中利用椭圆坐标系可以提高计算精度,减少计算量．建立了二维柔性翅模型,分析了气动力、力矩及功率变化情况．对计算结果进行了分析,并指出扑动开始及结束阶段大的升力和阻力峰值的产生是平动加速、加速旋转及马格纳斯效应的叠加;小的峰值归因于凸向来流和凹向来流作用;与压力、压力力矩和平动功率相比,黏性力、黏性力矩及转动功率较小,可以忽略． 相似文献
7.
土地流转、规模经营与农村劳动力的转移和就业 总被引：3，自引：0，他引：3
家庭联产承包责任制对农村劳动力转移的影响是深刻而又复杂的，由此产生了一对矛盾的结果。要解决这一矛盾必须建立土地流转机制，扩大经营规模。土地流转、规模经营不会导致大范围的农业劳动力失业。 相似文献
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文章从学校科学发展战略的高度,论述了文化力置于学校发展内涵,是文化育人理念体现的育人特色,是育人目标形成的核心力,而学校竞争力的大小则取决于这一核心力的聚积及其强弱程度。认为学校文化战略的创设,重在学校文化形态以“理念载体、环境载体、活动载体、教学载体、制度载体、行为载体”所产生的“力”。而学校文化战略倡导“德育为先”创新能力为重的培养意识和育人体系,则是理念精神特色价值的含义。 相似文献
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E. A. M. Heijnsdijk A. Pasdeloup A. J. van der Pijl J. Dankelman D. J. Gouma 《Annals of dyslexia》2000,50(1):980-985
Background: Due to the limited force feedback provided by laparoscopic instruments, surgeons may have difficulty in applying the appropriate force on the tissue. The aim of this study was to determine the influence of force feedback and visual feedback on the exerted pinch force. Methods: A grasper with a force sensor in the jaws was developed. Subjects with and without laparoscopic experience grasped and pulled pig bowel with a force of 5 N. The applied pinch force was measured during tasks of 1-s and 1-min duration. Visual feedback was provided in half the measurements. Force feedback was adjusted by changing the mechanical efficiency of the forceps from 30% to 90%. Results: The mean pinch force applied was 6.8 N (± 0.5), whereas the force to prevent slippage was 3.0 N ( ± 0.4). Improving the mechanical efficiency had no effect on the pinch force for the 1-s measurements. The amount of excessive pinch force when holding tissue for 1 min was lower at 30% mechanical efficiency compared with 90% (105% vs 131 %, p = 0.04). The tissue slipped more often when the subject had no visual feedback (2% vs 8%, p = 0.02). Conclusion: Force feedback and visual feedbacK playa more limited role than expected in the task of grasping tissue with laparoscopic forceps. 相似文献
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试验选用28日龄断奶的杜长定三元杂交仔猪28头,随机分成2组,用于研究日粮中添加20g/t速大肥对断乳仔猪小肠粘膜结构及形态的影响,结果表明:与对照组相比,添加速大肥可有效地防止断奶后1周内小肠绒毛萎缩、隐窝深度加深,降低断奶后2周内空肠固有膜厚度,这表明了在仔猪日粮中添加速大肥可以改善仔猪肠道的通透性的对营养物质的吸收功能. 相似文献
12.
宁建华 《阜阳师范学院学报(社会科学版)》2004,(5):28-31
农村剩余劳动力有两大主要转移动因 :一为城乡差距 ,二是地区差异 ,由此造成了剩余劳动力由农村向城市、由经济落后地区向经济相对发达地区转移的格局。除此之外 ,在经济落后地区传统种植业效益低下酌情况下 ,还可以因地制宜地发展畜牧业、渔业、副业等 ,由此又带来了农村剩余劳动力转移的第三种途径。在目前城市失业率大幅上升、经济发达地区就业岗位越来越“稀缺”的前提下 ,由农村向小城镇或户口所在地的县市、由农业向乡镇企业 ,由种植业向其它行业的转移 ,将会是我国长时间存在的一种有效途径和发展趋势 相似文献
13.
E. A. M. Heijnsdijk A. Pasdeloup A. J. van der Pijl J. Dankelman D. J. Gouma 《Annals of dyslexia》1968,50(1):980-985
Background: Due to the limited force feedback provided by laparoscopic instruments, surgeons may have difficulty in applying the appropriate force on the tissue. The aim of this study was to determine the influence of force feedback and visual feedback on the exerted pinch force. Methods: A grasper with a force sensor in the jaws was developed. Subjects with and without laparoscopic experience grasped and pulled pig bowel with a force of 5 N. The applied pinch force was measured during tasks of 1-s and 1-min duration. Visual feedback was provided in half the measurements. Force feedback was adjusted by changing the mechanical efficiency of the forceps from 30% to 90%. Results: The mean pinch force applied was 6.8 N (± 0.5), whereas the force to prevent slippage was 3.0 N ( ± 0.4). Improving the mechanical efficiency had no effect on the pinch force for the 1-s measurements. The amount of excessive pinch force when holding tissue for 1 min was lower at 30% mechanical efficiency compared with 90% (105% vs 131 %, p = 0.04). The tissue slipped more often when the subject had no visual feedback (2% vs 8%, p = 0.02). Conclusion: Force feedback and visual feedbacK playa more limited role than expected in the task of grasping tissue with laparoscopic forceps. 相似文献
14.
钱晋武 章亚男 孙麟治 秦新捷 沈耀宗 QIAN Jin-wu ZHANG Ya-nan SUN Lin-zhi QIN Xin-jie SHEN Yao-zong 《上海大学学报(英文版)》2000,4(3):235-238
The micro robot based on screw motion wheels, which features high payload/mass ratio, fast and continuous motion, adaptation
to pipe diameter or roundness variations, is suitable for locomotion and inspection inside small-diameter pipelines. The robot
inspection system, Tubot I, developed at Shanghai University is composed of locomotion mechanism with an inner motor, a micro
CCD camera and a monitor outside the pipeline. In the paper, the kinematics and statics analyses are presented for the screw
locomotion system of Tubot I. The moving characteristics are obtained from experiments on the robot prototype.
Supported by National High-Tech R & D Program in China(863-512-9704-26,863-512-9804-18) 相似文献
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王宁 《昆明师范高等专科学校学报》2010,32(2):43-47
昆明市晋宁县是典型的西部农业县,其城乡一体化农村劳动力就业到人力资本、就业服务机制等多种因素的制约。对此提出建议：1．统筹城乡产业发展,推进农业产业化,为农村劳动力转移就业创造条件;2．推进农村城镇化进程,促进农村劳动力转移就业;3．统筹城乡就业,建立统一的就业服务体系,为农村劳动力就业构建公平的环境;4．统筹城乡公共事业发展,增强农村劳动力抵御社会风险及市场风险的能力。 相似文献
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农村剩余劳动力的转移与培训 总被引：1，自引：0，他引：1
农村剩余劳动力的转移，需要通过推进农村城镇化、农业产业化进程，加快农业信息化建设来实现。农村剩余劳动力的培训是实现转移的保证，可围绕劳动力的就地转移与异地转移开展富有实效的、多样化的教育及培训活动。 相似文献
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曲克敏 《成都航空职业技术学院学报》2014,(2):82-85,92
回望昨天,中国高职经历了以示范建设提升硬实力的第一次浪潮,基本上形成了导向力、吸引力和效仿力,成功地实现了从学科教育到技能教育的转型.展望明天,以提升软实力为主的高职第二次浪潮的到来,将使高职教育完成从技能到文化的升华,形成向心力、凝聚力和执行力,并在制度、课程、团队、集团化等方面均衡发展,最终形成高职软实力的核心即高职文化发展的合力. 相似文献
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李琳峰 《河北能源职业技术学院学报》2002,2(3):85-86
本文就静摩擦力做功以及在静摩擦力做功过程中机械能守恒问题，结合实例做进一步讨论。从而得出系统内静摩擦力做所做的功不会引起本系统机械能的变化，静摩擦力做功的过程。只能使系统内的机械能之间相互转化或在物体之间传递机械能。 相似文献
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彭益武 《宁波职业技术学院学报》2014,(2):100-102
基于静电力测量原理,设计了一种簧片扭摆弱力测量系统,它主要由扭摆、信号检测系统和信号采集系统组成。该系统最大的优点是扭摆可以整体加工制作,框架、簧片、连接杆和检验质量是一个统一的整体,所以它们相互之间没有滑动,没有摩擦,具有很高的灵敏度。根据设计参数,如果系统的输出电压噪声为10 mV,那么在140μN的动态范围内,所设计的簧片扭摆弱力测量系统的测量精度能够达到1.4 nN。 相似文献