An unusually severe snow disaster in southern China in 2008 exposed variation among different species of bamboo: some species were highly tolerant to low-temperature damage, but some suffered extensive damage or death. Therefore, this study was conducted to determine the effects of cold stress on endogenous hormones and the expression of homologs of CBF 1 in four bamboo species differing in their tolerance to cold. All four bamboo species were subjected to cold stress with a temperature gradient (10, 5, 0, -5, and -10°C), and each low temperature treatment was maintained for 48 h. Results showed that ABA, GA 1 , and GA 4 were significantly affected by cold stress: ABA increased with cold stress in all species, while GA 1 and GA 4 reduced with cold stress. ABA levels and the ratio of ABA/(GA 1 ? GA 4 ) in leaves of Neosinocalamus affinis and Bambusa rigida were both higher than those of hybrid bamboo (Bambusa pervariabilis 9 Dendrocalamopsis grandis) and Dendrocalamus latiflorus for all treatments, while GA 1 and GA 4 were conversely lower as compared to the hybrid variety and D. latiflorus. Moreover, CBF 1 homolog was up-regulated during cold stress, with higher expression levels in the leaves of cold-tolerant species than cold-sensitive ones. Results revealed that high levels of ABA and CBF 1 , as well as the ABA/GA s balance, are important in increased plant resistance to cold stress.

Dujiangyan Irrigation Project promotes the sustainable development of economy and society in Chengdu plain, which plays an important ecological role and has great historical, cultural and social values. As an significant infrastructure, Dujiangyan project not only optimizes the river system distribution in Chengdu plain and improves the ecological living environment of Chengdu plain, but also grants Chengdu plain a rich connotation of water cultures, such as scientific concept of water management, advanced water-control techniques and the customs of loving water and protecting water. These are all the ecological wisdom of ancient urban construction. This essay summarizes the ecological and cultural wisdom of Dujiangyan irrigation project, its influences on the development and living environment of Chengdu plain. It not only provides some pretty enlightenment for rationality and moderation of urban infrastructure construction, also is an important reference of sustainable development. At the same time, this paper puts forward the importance of cultural relics in the process of sustainable development, which provides a new idea about the research on the future urban infrastructure.

Biodiversity protection, conserving and utilizing natural resources to its maximum is the foundation of contemporary social stability and sustainable development of our modern society and is the trend of landscape planning. Reforming the nature based on the basic theory of ecology, the idea of sustainable development, the methods of landscape planning, in order to create a landscape ecological planning pattern which will not cause pollution and secondary pollution and generate landscape ecological function to the upmost.

Dynamic characteristics of the structure have a significant effect on the performance of the structure. Modal test is a common method to obtain structural dynamic characteristics. However, due to the mass effect of the transducer, the measured results of lightweight structure are inaccurate. This paper proposes using strain gauges to test the mode of lightweight structures, and we take the cantilever beam as an example. The paper derived strain modal expressions. We use the strain gauges, the accelerometers and the finite element simulation to test the modal of the cantilever. To compare and analyze the experimental data, it illustrates that the strain modal test methods can measure the bending mode of the beam effectively.