Host tree unsuitability recognized by pine shoot beetles in flight

Summary In spring, the landing rate of flying European pine shoot beetles,Tomicus piniperda L., on injured Scots pine diminishes as colonization continues. This is due to olfactory cues that indicate progressive host degradation. Verbenone was shown to play a role in the beetle's recognition of this unsuitability of a formerly suitable host, since the compound was increasingly released from colonized tree sections as they aged, but not from uninfested sections. Also, the release of verbenone at natural rates in the forest inhibited the attraction of beetles to host monoterpenes.     

草酸过氧钒催化氧化α-蒎烯反应研究

以草酸过氧钒为催化剂,过氧化氢为氧化剂,研究了α-蒎烯的氧化反应.考察了溶剂、温度、催化剂用量、反应时间等因素对催化性能的影响.结果表明高价态V5+与草酸形成的双过氧配合物催化剂,在催化剂质量分数为8.0％、反应温度40℃、丙酮溶剂中反应8h条件下,α-蒎烯转化率达到68.7％,主产物马鞭草烯酮的选择性为34.9％.对催化剂进行了初步的回收利用.     

马鞭草烯酮衍生物电子结构与电子光谱的量子化学研究

利用量子化学半经验AM1及INDO／SCI方法研究了双氰基马鞭草烯酮衍生物的电子结构和光谱性质，以全自由度优化几何结构为基础，计算了各化合物的电子光谱，计算结果表明，不同取代基的引入对体系的电子结构和电子光谱等都有一定的影响，空间结构对光谱影响较大，所讨论体系在可见波段都具有较好的透明性。