Group dynamics and record signals in the ant Temnothorax albipennis

Many purely physical complex systems, in which there are both stochasticity and local interactions between the components, exhibit record dynamics. The temporal statistics of record dynamics is a Poisson process operating on a logarithmic rather than a linear time scale (i.e. a log-Poisson process). Record dynamics often drive substantial changes in complex systems when new high water marks in partially stochastic processes trigger new events. Social insect colonies are exemplary complex biological systems in which many of the local interactions of the components have been moulded by natural selection for the common good. Here, we combine experimental manipulation of ant colony demography with modelling to test the hypothesis that social interactions are the mechanism underlying the record dynamics. We found that compared with the control, log-Poisson statistics were disrupted in colonies in which the pattern of interactions was modified by the removal of the brood, and disappeared completely in ‘callow’ colonies composed entirely of very young workers from the same age cohort. We conclude that a subtle interplay between the demography of the society and the pattern of the interactions between the ants is crucial for the emergence of record dynamics. This could help identify what makes an ant colony a cohesive society.     

针状电极电沉积枝晶生长的模拟与实验

采用改进的扩散限制凝聚模型对针状电极电沉积镍枝晶的形状和生长过程进行了数值模拟研究,采用电沉积设备进行了验证性试验。结果表明:实验获得的电沉积实物与模拟得到的粒子簇形貌非常相似,两者的分形维数也很接近,用扩散限制凝聚模型来说明枝晶生长规律是有效的,模型中的模拟参数分别与电沉积参数存在着内在的对应联系;模拟生成的粒子沉积层具有明显的分形结构。     

磺化酞菁镓的二聚现象研究

采用分光光度法研究了磺化酞菁镓的二聚现象；测定了二聚常数Ｋｄ，讨论了ｐＨ值、离子强度、水、温度等因素对Ｋｄ的影响。研究结果表明：磺化酞菁镓的二聚反应可表示成： ２ＳＰｃＧａＯＨ→（ＳＰｃＧａ）２Ｏ＋Ｈ２Ｏ且磺化酞菁镓的二聚常数随着离子强度、磺酸基数目、水的浓度的增加而增加。     

两种新的水溶性卟啉的离解常数测定及酸碱诱导聚合

研究了ｍｅｓｏ－四卟啉和ｍｅｓｏ－四卟啉的离解常数。ＴＢＰｈＰ的离解常数为：ｐＫａ４＝１．１３．ｐＫａ３＝１．８８，ｐＫＡ２＝１２．２１；ＴＴＰＳ的离解常数为：ｐＫａ４＝４．４７，ｐＫａ３＝６．２６。外还发现了两卟啉的酸碱诱导聚合。     

Olfactory responses ofIps plastographus maritimus lanier (coleoptera: Scolytidae) to insect and host-associated volatiles in the laboratory

Attraction of both sexes ofIps plastographus maritimus Lanier to bark-phloem-xylem discs of Monterey pine,Pinus radiata D. Don, was demonstrated in the laboratory. Increasing concentrations of male and female volatiles trapped separately and released in a one-to-one ratio decreased attraction for both sexes combined. Attraction of both sexes to volatiles derived from males and females tunneling together in a one-to-one ratio increased with increasing concentration of extract. Attraction of males and females to male-infested discs and to trapped male volatiles increased with increasing dose of males or male extract. Attraction of males and females to female-infested discs and to trapped female volatiles was also demonstrated. The presence of females in male galleries reduced the attractiveness of infested disks to both sexes combined. Increasing numbers of females, tunneling separately from males in the same disc, reduced attraction of males, but not females. When a constant attractive dose of male volatiles was released with increasing doses of female volatiles, there was no difference in response of either sex when female volatiles were present compared with the response to male volatiles alone. When a constant attractive dose of male volatiles was released with increasing concentrations of volatiles derived from males and females tunneling together in a one-to-one ratio, attraction ofI. p. maritimus decreased. Response of females was frequently higher than that of males to the same attractant source. Hence, both sexes produce an attractant, and both sexes tunneling together in the same gallery reduce attraction of males and females to an attractive dose of male attractant.