Delayed greening of young leaves is a ubiquitous and visually striking phenomenon in the tropics. Here, we investigated the potential ecological functions of red coloration patterns in young leaves. To detect any protective function of the red coloration on the young leaves, leaf damage by insect herbivores was recorded in the field. To determine capacity for chemical defense, the concentrations of tannins and anthocyanins were measured in both young and mature leaves. To test the hypothesis that anthocyanins function as photoprotective molecules, chlorophyll content, maximum photochemical efficiency of PSII (F v /F m ), non-photochemical quenching (NPQ), and effective quantum yield of PSII (F PSII ) were measured in the field. Phylogenetic relationships were analyzed to test the relationary significance of the occurrence of redness in young leaves. Compared to the coloration in non-red leaves, young red leaves had significant higher anthocyanins and tannins content and lower herbivore damages. Young, red leaves had the lowest F v /F m values, which were significantly lower than those of non-red leaves. NPQ values in young red leaves were comparable to those of other groups. Although young red leaves had high F PSII , these values were significantly lower than those of the other three groups. The results suggest that the red coloration of young leaves protects them from insect herbivory primary by chemical defense through high concentrations of tannins and anthocyanins. Additionally, low F v /F m values in young red leaves indicate that anthocyanins might not be functioning as light attenuators to compensate for insufficient photo-protection mediated by NPQ. And finally, red coloration in young leaves is predominantly a result of adaptation to heavy herbivory stress but without significant intrinsic phylogenetic relationship of plant species.

A novel series of oligomers consisting of thiophene as a p-type unit and oxadiazole as an n-type unit were separately synthesized. On the basis of the characterization of photophysical and electrochemical properties, the structure-property relationships of the oligomers were investigated. Cyclic voltammogram studies showed that changing the number of thiophene and oxadiazole units could effectively modulate the electronic properties of the p-n diblock and triblock oligomers. The effect of molecular regiochemistry on electronic properties is also investigated. The observed electronic properties were consistent with theoretical calculations. These systems serve as excellent examples, demonstrating the band gap control principle in the p-n heterostructure oligomers.

In ancient Chinese history, the Western Zhou Dynasty has long been renowned for having expanded its control and territory into many other states. However, historical documents and archaeological records of this period are limited; thus the early history of the Western Zhou Dynasty's operation in eastern China and its establishment of the Qi and Lu states have been unclear. The discovery of the Chenzhuang city site in Gaoqing County, Shandong Province, with chariot-horse pits, an altar and bronze vessels with inscriptions, adds a new line of evidence for studying the history of this period. However, with no direct evidence, the nature of the city site is controversial. Plant remains, especially a large number of sweet clover seeds, recovered from this site by systematic archaeobotanical methods provide an important source of information for research into the site's function. Considering that modern sweet clover is superior fodder for horses and the sweet clover seeds from the Chenzhuang site coexist with chariot-horse pits and horse remains, it is suggested these sweet clover seeds might represent the fodder of battle steeds. This suggestion supports the opinion of those who believe the Chenzhuang city site was once an important military city of the Western Zhou Dynasty in eastern China.Early Western Zhou Dynasty, military city, Chenzhuang site, archaeobotanic evidence, carbonized sweet clover seeds