紫茎泽兰精油各馏份对4种仓库害虫的杀虫活性

：用紫撬泽兰精油的20℃～150。C，150℃一200℃，20．0℃，230℃．230屯。300℃和300℃以上馏协，分剐以 稚．簦嘴，L的熏蒸浓爰楚理米象、玉采象、簿豆象牵蚕熹象，螬幕表磷凄5争犍静中，娃15。℃～200℃馏傍转荣虫活性 最高，其洗是20℃一150℃和200℃～230气馏份，而300℃以上馏份的杀虫活性靛低。进一步的生测结装表明．150屯一 200℃增傍对米象、玉来氧、绿黛象和善豆象24h的l(葡分莉为15 5li4，17．8124，培．0302和16．2671mg／Lo

Microstructures and mechanical properties of as-cast Mg–5Al–0.4Mn–xNd (x=0, 1, 2 and 4) alloys

Mg-5Al-0.4Mn-xNd (x=0, 1, 2 and 4wt.%) alloys were prepared by metal mould casting method. The microstructures and mechanical properties were investigated. The results demonstrated that Al11Nd3 phase was formed and mainly aggregated along the grain boundaries with the addition of Nd. Meanwhile, the grain sizes were greatly reduced with the increasing Nd content.

2,5-双(4-羟基苯亚甲基)环戊酮中双电荷离子存在的串联质谱证据

应用串联质谱的碰撞诱导解离和联动扫描技术，研究了2,5-双(4-羟基苯亚甲基)环戊酮的质谱解离特征，提供了双电荷离子存在的实验证据。进一步对双电荷离子(m/z146)的碰撞诱导解离碎裂进行了讨论。

环化顺1，4－聚丁二烯浓溶液的流动行为

大多数线型高聚物浓溶液的流动行为呈现非牛顿性，线型顺１，４－聚丁二烯（ＬＢＲ）亦然，而环化顺１，４－聚丁烯（ＣＢＲ）的浓溶液在浓度达１７．８％时仍表现为牛顿流体。ＣＢＲ溶液的临界缠结浓度明显地高于ＬＢＲ，ＣＢＲ分子链间的缠结效应比ＬＢＲ弱得多，这是ＣＢＲ的分子链结构特征所致。