排序方式: 共有4条查询结果,搜索用时 156 毫秒
1
1.
2.
3.
就自制的稜状和针状两种结晶状态的三聚甲醛进行了固态辐射聚合,制得特性粘数为0.8和K_(222)值力3.4%/分(未酯化的)的聚合物,经酯化后,可压制成膜。 在不同剂量率下研究了聚合转化率与辐照时间的关系,当累积剂量在 2×10~5拉特之前,聚合转化率与剂量呈线性关系,随后转化率出现一极限值(74%以上)。聚合物的特性粘数随剂量的增加而减小。在所研究的剂量范围内(4.1—89拉特/秒)聚合初速率与剂量率呈线性关系。剂量率对聚合物的特性粘数影响不大。 在-78℃到65℃温度范围内进行了温度对聚合速率影响的试验,在0℃以下时不聚合,接近熔点时聚合速率最快,超过熔点(62℃)时,则几乎不聚合。单体的结晶状态及晶体的大小对聚合速率有较大的影响。 相似文献
4.
The present studies show that there is a biocommunity including 59 kinds of organisms in and around the focus of angelica pockmarked disease to form a soil food web. These results add new content to the relationship among food webmembersr~[1, 2]. The studies prove that 6 species of Fusarium are pathogenes, the wounds caused by underground insects and artificial factors are beneficial to pathogene infection, and invertebrates carrying pathogenes aggravate the disease. According to the tests, a disease control method is proposed and applied to 14, 000 mu in Gansu Province, and economic and social benefits have been obtained. The present studies are part of the state projects on technological development of agriculture, animal husbandry and fishery. 相似文献
1