Are host plants important in pheromone-mediated mating systems of lepidoptera?

Summary The role of host plants in the synthesis and release of lepidopteran sex pheromones is examined. Females synthesise pheromones de novo and pheromone quality is not markedly influenced by larval food sources. However, host plants may have a significant effect on different physiological and behavioural parameters associated with pheromone production. Males in some species of Nymphalidae and Arctiidae use secondary plant compounds, such as pyrrolizidine alkaloids, as a pheromone precursor. In such cases these plant compounds serve an additional role, such as protection against predation, and may reflect potential male reproductive investment. In the one instance where the effect of larval host plants on the de novo synthesis of a male sex pheromone was examined, larval nutrition did not alter either the quality or quantity of the hairpencil contents.     

Li/LiClO_4/V_6O_(13)试验电池研究

分别采用V_6O_(13)分散复合型和层压复合型高分子薄膜作为锂二次电池的阴极活性材料,制成了真空塑封式试验电池。比较了两者的工艺特点和电池性能。     

二次创新竞争模型与企业竞争战略分析

本文用二次创新竞争模型描述了技术输出方和技术引进方的二次创新竞争情形。分析了技术引进方的二次创新在市场竞争中“后发优势”的成因。指出必须摒弃传统的对引进一消化、吸收－创新的单纯技术和封闭系统观，而立足于引进技术与市场的结合，用开放系统中的二次创新竞争制定正确的竞争战略，在赢得市场竞争优势的同时，培养自言创新能力。     

聚合物的一维振子链模型

一维聚合链可以用一维振子链来模拟.其中联接振子而组装链的键可以分为主键和次键.一维振子链的非线性过程要受主键或次键的非线性过程所控制,本文讨论了在主键或次键的非线性作用下所引起的一维振子链的非线性过程.在一定条件下,我们可以得到解析的孤子解.     

我国技术市场的成就和新时期的主要任务

近 2 0年来 ,我国技术市场的发展取得了巨大成就 ,本文在总结我国技术市场取得的 1 0大成就基础上 ,提出了未来 2 0年我国技术市场发展的主要任务     

二硫化钨高压合成与其高价离子固态二次电池

在高温高压条件下合成了层状结构的二硫化钨，分析了其结构，用其作阴极材料研究了全固态镁、锌／二硫化钨固态二次电池。     

圆筒型直线异步电动机初级铁损和实心钢次级参数的分析计算

针对圆筒型直线异步电动机电磁结构的特殊性,本文利用聂孟(HenMaH)关于平面电磁波在实心铁磁物质中的表面波阻抗的结论,提出一种关于这种电机的初级铁损和钢次级参数的简便实用的解析算法。计算方法中考虑了铁磁体非线性磁化曲线、磁滞以及直线电机静态边端效应的影响,实测结果与计算结果基本相符,证实了该方法的有效性。     

New tamjamine class alkaloids from the marine ascidianAtapozoa sp. and its nudibranch predators. Origin of the tambjamines inAtapozoa

Summary Two new tambjamine class alkaloids, possessing ichthyodeterrent properties, have been isolated from the organic extracts of the marine ascidianAtapozoa sp. and its nudibranch predators. The structure of the new metabolites were elucidated through interpretation of their physical and spectral data and by comparison with spectral data for related compounds. Microscopic examination ofAtapozoa considering the yellow color of the tambjamines suggested thatAtapozoa is capable of the de novo biosynthesis of these metabolites.     

有关“二次钝化”现象的探讨

本文对采用恒电位法测定奥氏体不锈钢316L在NaCl溶液中的阳极极化曲线时产生“二次钝化”的现象进行了研究。在对实验进行分析的基础上,提出把Prazak的“二次钝化”理论的适用范围扩大到点蚀过程;并引用Prazak的理论对NaCl溶液中316L不锈钢的“二次钝化”现象进行了分析讨论。结论认为:“二次钝化”现象只有在特定的材料,介质和环境条件下才能产生。尽管在“二次钝化”发生时,在H_2SO_4溶液中发生的是不锈钢表面膜的过钝化溶解过程,而在NaCl溶液中发生的是点蚀过程,但产生“二次钝化”的机理是相同的。