简介:摘要:本文通过在熔炼炉试验及检测数据说明,在铝合金生产中,添加合金废料对合金力学性能产生明显影响,即废料比表面大,力学性能下降,反之,力学性能提高。并分析了产生影响的原因。
简介:摘要:本文研究了Nb对0.4%Si无取向硅钢电磁性能的影响及分析了Nb对微观组织、织构及夹杂物的变化规律。结果表明,在工业化生产中,当Nb含量从3ppm增加到20ppm时,夹杂物数量由7.08X106个/mm2增加到8.63X108个/mm2,这些尺寸细小的Nb夹杂物和MnS、AlN等夹杂物大量富集钉扎在晶界处,晶粒无法正常长大,导致白片晶粒组织出现非常明显的细晶偏聚现象,消除应力退火后,晶粒组织则发生了明显的局部晶粒异常长大和较多的细晶现象,晶粒组织更加不均匀,从而导致铁损劣化。另外,Nb含量高带来较多细小含Nb夹杂物,抑制了粗大、发达热轧组织的形成,导致有利织构旋转立方织构{100}<011>减弱,不利织构{111}和{111}增强,最终导致磁感强度降低。
简介:AbstractHepatitis C infection is not uncommon in pregnant women. Vertical transmission of the virus from mother to fetus is estimated at 4%-8%, however this transmission rate is significantly higher when the mother is co-infected with HIV. Intrauterine blood transfusions can be a necessary part of management for certain perinatal conditions like hemolytic disease of the fetus. Currently there is no published material available on the vertical transmission risk of HCV infection to the fetus as a result of this procedure, irrespective of HIV coinfection. We present a case of a pregnant woman co-infected with HCV and HIV that required an intrauterine blood transfusion during pregnancy. Vertical transmission of either infection to the child did not occur. This provides important evidence that vertical transmission of HCV and/or HIV does not necessarily occur with intrauterine blood transfusions.