排序方式: 共有82条查询结果,搜索用时 15 毫秒
31.
提高PLC控制系统可靠性的措施 总被引:2,自引:0,他引:2
王成福 《金华职业技术学院学报》2005,5(1):11-13
针对某些条件恶劣的工作环境,经过多年的探索与实践,总结出若干条行之有效的措施——主要有严格接地、隔离变压器供电、输出模块选择、软硬件安全保护等。采取这些措施后设计的PLC控制系统,能在恶劣的环境条件下可靠运行,降低堆护成本,提高生产效率。 相似文献
32.
采用周期浸润加速腐蚀试验的方法,对某型飞机42框横梁模拟件分组进行了不同时间的加速预腐蚀试验,并通过随机载荷谱下的疲劳试验获得了预腐蚀后模拟件的疲劳寿命。结果表明,在加速腐蚀时间不大于300小时的情况下,预腐蚀对42框横梁结构模拟件疲劳寿命的影响不明显。 相似文献
33.
电子测量系统工频干扰与接地问题的研究 总被引:1,自引:0,他引:1
在工频干扰模型基础上,通过对示波器和毫伏表的电源变压器漏电阻和等效漏电压典型值的测量,估算了工频干扰电压的幅度,从而说明电子测量系统各设备间共地连接的必要性,并介绍了共地方式在交流电桥等实践中的应用实例. 相似文献
34.
Collaborative information seeking: The combined activity of information seeking and collaborative grounding 总被引:1,自引:1,他引:0
Since common ground is pivotal to collaboration, this paper proposes to define collaborative information seeking as the combined activity of information seeking and collaborative grounding. While information-seeking activities are necessary for collaborating actors to acquire new information, the activities involved in information seeking are often performed by varying subgroups of actors. Consequently, collaborative grounding is necessary to share information among collaborating actors and, thereby, establish and maintain the common ground necessary for their collaborative work. By focusing on the collaborative level, collaborative information seeking aims to avoid both individual reductionism and group reductionism, while at the same time recognizing that only some information and understanding need be shared. 相似文献
35.
论竞技体操跳马落地技术稳定性 总被引:4,自引:0,他引:4
姚吉庆 《武汉体育学院学报》2003,37(3):74-76
采用文献资料法、调查访问法和生物力学分析法,对跳马落地技术稳定性进行了分析揭示了落地技术的力学原理和落地技术稳定性构成因素,井针对性地提出了训练方法。 相似文献
36.
张宁 《贵州教育学院学报》2005,16(4):18-21
随着低压供配电系统中的负荷设备种类的多样化和数量的日益增长,各种电气设备的接地是分开独立接地,还是共用接地,已成为广大设计工作者十分关心的问题。实践表明,采用共用接地有不少优点,但也存在一些问题,需要正确加以分析和对待。 相似文献
37.
38.
《Africa Education Review》2013,10(5):60-69
AbstractHigher education institutions (HEIs) are drivers of social change embedded in a society which is experiencing increasingly complex and multifaceted crises. This is partly attributable to the use of conventional and deterministic problem-solving curricula. A combination of a transdisciplinary approach and indigenous knowledge (IK) as transformative tools in complex systems is critical for pedagogy. This interface embraces the African heritage in Western epistemology putting it on a curricula pedestal which is currently Western-oriented. This article shows how a transdisciplinary approach and IK can transform pedagogies in HEIs through mutual learning and dialogue across disciplines by reflecting on the Life Knowledge Action/Grounding Programme which is a course offered at the University of Fort Hare, South Africa. The article suggests an integration of transdisciplinarity and IK as powerful catalysts for transformation in pedagogical design. 相似文献
39.
为了解决谐振接地系统,发生单相接地故障时基于单一暂态或稳态的选线策略的故障选线装置的选线误判率过高的问题,本文提出了一种基于综合选线的策略即零序电流增量法和暂态零序电流方向互异法。实现了对稳态和暂态两方面进行零序故障电流的综合选线,从而进一步提高选线的准确性。基于这种综合选线策略的谐振接地选线装置被研制出来,并在模拟电网进行实验。实验结果表明:该装置具有实时记录并显示谐振接地系统发生单相接地故障时故障线路和非故障线路零序电流的稳态增量的变化和故障线路零序电流暂态方向的不同,并通过DSP对故障线路做出准确、可靠的判断。 相似文献
40.
武术跳跃动作落地稳定性探讨 总被引:3,自引:0,他引:3
针对学生在武术套路演练中容易出现跳跃动作落地不稳,造成附加支撑或摔倒等问题,结合从事武术专业教学的经验,进行调查、分析,从技术、心理和体能方面探讨造成学生跳跃动作落地不稳定的原因。 相似文献