高压输电线路跨越建筑物工频电场研究

当高压输电线路跨越或邻近建筑物时,线路下方区域工频电场会发生不同程度的畸变,此时,传统的二维模型已无法正确描述该情况时线路下方工频电场的分布。利用自编仿真软件进行模拟,并结合实测数据,研究和分析高压输电线路跨越或邻近建筑物时线路下方的工频电场分布和变化趋势。     

The use of the embryo‐culture techniques in the research on the Teratogenic and Mutagenic properties of metals†

Actually, embryos can be cultured from the one‐cell stage up to the blastocyst stage, and their development can be easily monitored at any time: severe effects caused by toxic compounds are traduced by rapid embryonic death, less pronounced effects can be expressed by a lowered cleavage activity or by an arrest of the development from a particular stage. The system can be improved by transferring the embryos at the blastocyst stage in another more complete medium where they can “implant”; and form an inner cell mass with differentiated ectoderm and endoderm. Since last years, it has also become possible to culture postimplantation rodent embryos for short periods involving a number of particularly critical stages of organogenesis, such as the formation and closure of the anterior neuropore. Embryo‐culture also represents a useful system to study cytogenetic effects of chemicals which are often linked to lethal or teratogenic effects. These different possibilities are illustrated by examples of studies already performed with metals, and dealing with their teratogenic and/or cytogenetic effects on pre‐ and postimplantation rodents.     

Chromosome aberrations as indicator of technogenic impact on conifer stands

The level of chromosome aberrations at different stages of mitosis has been studied in the seed sprout meristem of four conifer species growing in the Southern Urals in areas differing in the kind and degree of industrial pollution. The results provide evidence for the adverse effect of pollution on the chromosomal machinery of these species. With respect to environmental quality assessment, the Scots pine is the most sensitive indicator species among conifers growing in the Southern Urals and analysis of chromosome aberrations in anaphase-telophase cells is most effective among the cytogenetic methods tested.