基于粗糙集理论和生命初态信息的继电器寿命预测方法

工作寿命是表征产品可靠性的重要特征量。对于继电器这类长寿命产品,以寿命为指标进行产品筛选的方法目前还未得到深入研究。近来通过对继电器寿命试验数据进行分析发现:继电器个体的寿命与其生命初期的性态有关,初期性态较好的个体其寿命也较长,反之则寿命较短。本文基于这一发现提出了继电器的个体寿命预测与筛选方法,即首先通过寿命试验获取一组样本在生命初期的性能参数值与寿命值,然后利用粗糙集理论中的属性约简提取一组与寿命相关的性能参数,并建立一组寿命决策规则。此后对于任一同型产品,只要测出其生命初态信息即可根据这组规则预测其寿命,进而完成以寿命为指标的继电器产品筛选。本文最后进行了实例分析,结果表明了该方法的有效性。

环境内分泌干扰物对母婴健康影响研究进展

在概述环境内分泌干扰物的基础上,从通过与核受体结合的基因作用及非基因信号通路作用方面阐述了环境内分泌干扰物的作用机制,并探讨了环境内分泌干扰物对母婴健康的影响,包括对母亲的影响及对胎儿、婴儿的影响方面。同时强调应重视其对激素水平不稳定的孕期母体及敏感初期生命的影响。

Nuclear Transition Between the Conjunction Cells of Phaeodactylum tricornutum Bohlin (Bacillariophyta)

Phaeodactylum tricornutum is one of the important marine diatoms for oceanic primary production. Its reproduction has profound significance in the life cycle; however, the nuclear behavior during its sexual reproduction was not clear. In this study, we observed the nuclear transition and determined its correlation with cell conjunction. It was found that two cells jointed at their apices first and swung and aligned each other immediately, and nucleus from one cell was able to transfer into another one during cell conjugation. The cell pairs conjugated for nuclear transition were different from those formed in mitosis in hypovalve thickness and cellular arrangement. Our findings proved the existence of sexual reproduction in P. tricornutum.