Results 31 to 40 of about 2,295 (121)
Shiyou jixie, 2012 大型石油钻机常配置2台电动机同时驱动同一个控制对象，这就要求2台电动机同步运转，否则会导致齿轮箱的机械损坏。采用西门子6SE70变频器主从控制技术，以S7-300PLC为控制中心，通过Profibus总线与调速装置进行通讯，以SIMOLINK板来传输主机的转矩给从机，可以实现2台电动机同步运转，保证传动系统的稳定性。介绍了利用Profibus总线和SIMOLINK相结合实现钻机主从控制的原理、方法和控制过程，并说明了控制操作中应该注意的几个问题。
李崇博, 杨蕊, 李鹏飞, 钟志伟
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Emotion and the Advocacy Coalition Framework: An Affective Dynamics Perspective
Policy Studies Journal, EarlyView.ABSTRACT Despite extensive evidence that emotion and cognition are deeply intertwined, the Advocacy Coalition Framework (ACF) lacks an analytically independent emotional mechanism in its causal architecture—an omission that may be particularly consequential in policy subsystems structured around morally charged, identity‐laden policy disputes.
Moshe Maor
wiley +1 more source
Gaoya dianqi, 2020 高压断路器的稳定工作是电力系统正常运行的关键,为了优化其分合闸控制的性能,研究了一种由永磁同步电机（PMSM）驱动的高压真空断路器操动机构及由DSP作为主控模块的伺服控制系统。构建了一台由126 kV真空断路器、永磁同步电机、DSP及外围控制系统组成的实验装置进行实验。针对与电机转矩惯量比相关的定子尺寸与永磁体厚度进行了优化分析,并设计了与真空断路器性能匹配的控制系统程序流程。通过采用最大转矩电流比控制策略控制电机,可以实现真空断路器按预设的参考曲线进行分合闸操作。实验结果表明 ...
何保营 +7 more
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People and Nature, Volume 8, Issue 2, Page 270-282, February 2026.Abstract Chinese consumer demand for ivory threatens vulnerable African elephant populations, despite long‐standing efforts to combat the illegal wildlife trade. Behavioural science approaches have been proposed to address these systemic behaviours. However, their robust use remains uncommon in demand management interventions.
Molly R. C. Brown +3 more
wiley +1 more source
Conservation Biology, Volume 40, Issue 1, February 2026.Abstract Exploring heat tolerance and acclimation capacity can provide an effective approach to evaluating species’ sensitivity to extremely high temperatures due to climate warming. Despite some work on amphibian and reptile thermophysiological adaptation, related questions remain. We reviewed the literature to provide a synthesis of worldwide data on
Zijian Sun +8 more
wiley +1 more source
Jixie chuandong, 1999 研究了自由飞行空间机器人（ＦＦＳＲ） 捕捉运动目标的力矩控制算法及其仿真。在建立计算ＦＦＳＲ关节驱动力矩的求解算法的基础上，结合基于广义雅可比矩阵的分解运动速度控制法，提出了一种捕捉运动目标的力矩控制算法；并且计算机仿真验证了所提出算法的有效性。
李华忠, 洪炳熔
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Evolution of research on global amphibian declines
Conservation Biology, Volume 40, Issue 1, February 2026.Abstract In the late 1980s, the scientific community became aware of severe, enigmatic amphibian population declines. These declines triggered a wave of research focused on quantifying their extent and identifying key drivers. We used text‐analysis techniques, including topic modeling and geoparsing, to examine the evolution of research focused on ...
Jordann Crawford‐Ash +6 more
wiley +1 more source
Shiyou jixie, 2014 为了满足电驱动钻机大井距丛式井各系统整体平移要求，研制开发了相应的快速平移装置。该平移装置在机械钻机平移装置的基础上进行了改进，钻机主机通过π型梁可直接移过井口采油树；电传动平移装置采用新型整体式折叠管线槽，能有效避免控制信号受到干扰；低压钻井液循环通过动力橇转运，实现井口返出钻井液正常净化流程。该平移装置满足多井位、大井间距丛式井作业需求，可实现电驱动钻机与丛式井优势结合，且建井周期短，劳动强度低，搬迁费用少，适用于具备大井距丛式井油区开发。
刘 +7 more
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Gaoya dianqi, 2022 随着电力物联网的高速发展，庞大数量的分布式传感器的供电问题成为了亟待解决的技术难题。摩擦纳米发电机作为一种高效且低成本的新型供能技术，在自驱动传感领域具有极大的应用前景。文中提出并研制了一种面向电力物联网应用环境下的宽风速摩擦纳米发电机自驱动系统，创新地引入了同心双转轴的结构设计，使其在宽风速范围下能够有效收集风能并保证优异的输出性能。实验阶段搭建了基于风力涡轮机的风力测试平台，测试了不同风速下摩擦纳米发电机的基本电气性能和负载特性。最后构建并演示了所设计的摩擦纳米发电机自驱动系统 ...
冯运 +6 more
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Shiyou jixie, 2014 为满足俄罗斯油气田丛式井低温钻井作业的需求，研制了ZJ40/2250DBG轨道钻井装备。该钻井装备主要由轮轨式移运装置、底座、井架、钻井液净化系统、机泵组、控制系统以及井口工具等组成。整套装备和附属设备安装于交互式可续接的专用轨道上，通过装备自身液压动力驱动，按照设定的方向整体沿轨道滚动平移，实现作业区内丛式井的钻井作业。该装备利用工业网电动力，经交流变频驱动绞车、转盘、钻井泵和顶驱系统，其井架及底座均配套液压+机械式专用调平机构，确保钻机工作时井口对中。钻机适用于-45 ℃低温作业 ...
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