Plant Antifreeze Proteins and Their Expression Regulatory Mechanism

Low temperature is one of the major limiting environmental factors which constitutes the growth, development, productivity and distribution of plants. Over the past several years, the proteins and genes associated with freezing resistance of plants have been widely studied. The recent progress of domestic and foreign research on plant antifreeze proteins and the identifica- tion and characterization of plant antifreeze protein genes, especially on expression regulatory mechanism of plant antifreeze proteins are reviewed in this paper. Finally, some unsolved problems and the trend of research in physiological functions and gene expression regulatory mechanism of plant antifreeze proteins are discussed.

海洋环境下配电网设备线夹失效机理分析及寿命评估方法

设备线夹起着连接、紧固线路的作用,其健康状况直接影响供电可靠性。针对海洋环境下设备线夹失效造成线路故障占比高的问题,进行设备线夹失效机理分析并提出一种基于A-DBiLSTM(改进神经网络)的寿命评估方法。首先,通过设备线夹运行环境模拟实验建立失效进程与环境因素的关联模型,并提取关键故障特征,制定寿命状态评估指标;其次构建A-DBiLSTM模型,考虑多环境因素、强相关性环境特征对线夹运行状态的影响,输入环境特征和评估指标,并通过Attention机制重点赋权典型强气象特征,实现对线夹的寿命评估;最后基于浙江某海岛配电网设备线夹实际运行数据进行验证,结果表明:该方法能够准确评估配电网设备线夹在不同海洋环境下的寿命状态,对保障线路可靠性、改进线夹运行管理及提升设备质量具有实用价值。

油缸驱动肘杆合模机构开模瞬时停顿的研究

油缸驱动系统与肘杆合模机构间的动态性能不匹配造成了注塑开模过程中瞬时停顿的现象,提出改变肘杆合模机构运行的动力驱动及传动机构型式的解决办法,消除了肘杆合模机构开模瞬时停顿现象。

压电陶瓷驱动器装夹机构设计

采用直圆柔性铰链支撑的复合平行四杆机构,设计了一种压电陶瓷(PZT)驱动器的装夹机构。该机构具有导向精度稳定、响应速度快、分辨率高和无耦合运动等优点。从力学理论出发推导了柔性铰链刚度的简化计算公式,运用参数化的分析方法求得了柔性铰链结构参数对装夹机构应力、刚度及有效行程的影响。实验测得刚度和有效行程的理论计算误差分别仅为3.9%和1.4%,表明了该设计方法的可靠性与有效性。