Iron (Fe) plays an important role in the growth and development of the human body and plants. The effects of different Fe concentrations, 1-aminocyclopropane-1-carboxylic acid (ACC), and cobalt chloride (Co2+) treatments on plant growth, quality and the adaptive response to Fe deficiency stress were investigated in flowering Chinese cabbage. The results revealed that Fe deficiency stress inhibited plant growth. The content of vitamin C (Vc), soluble protein, and soluble sugar in leaves and stalks were significantly reduced under Fe deficiency stress, while the content of cellulose and nitrate was increased. Meanwhile, Fe deficiency stress obviously reduced the net photosynthetic rate and nitrate reductase (NR) activity of leaves. The balance system of active oxygen metabolism was destroyed due to Fe deficiency, resulting in the decrease of catalase (CAT) activity, superoxide dismutase (SOD) activity of roots and leaves, and peroxidase (POD) activity of leaves, while POD activity in roots and malonaldehyde (MDA) content were significantly increased. The treatments of Fe deficiency and ACC significantly reduced pH value of the root medium, promoted release of ethylene, and increased Fe3+ reductase activity, while Co2+ treatment showed the results opposite to those of Fe deficiency and ACC treatments. Thus, Fe deficiency stress could induce nitrogen metabolism, photosynthesis, reactive oxygen metabolism, pH of root medium, and Fe3+ reductase activity that was related to physiological adaptive response and tolerance mechanisms. We also found that ethylene could involve in regulating the adaptive response to Fe deficiency stress and improve the availability of Fe in flowering Chinese cabbage.Main ConclusionFe deficiency stress could induce nitrogen metabolism, photosynthesis, reactive oxygen metabolism, pH of root medium, and Fe3+ reductase activity that was related to physiological adaptive response and tolerance mechanisms.

Because it is difficult to monitor the quality of gravel pile (the length, the diameter) in composite foundation, the method of radar is put forward. Numerical simulations of radar monitoring on flexural pile are processed. The results show that the method of radar monitoring can be used to check the quality of gravel piles (length, diameter) accurately. Then this technology is applied in some highway project. By comparing with the results of another company, the characteristics including high precision and speed are found. So the technology can be far and wide used.

In this paper, , the combination of antenna array detection method of ground penetrating radar is put forward to solve the actual engineering problem that is difficult to monitor the integrity of the flexural pile composite foundation. The experiments of defects of six tamping soil cement piles find that the relative error of the pile position of defects is 5.25%. The result indicates that it is enough reliability to determine the pile defects by using the GPR method and can meet the engineering needs. Furthermore, the effect of age of cement, the ration between soil and cement, depth and types of defects on the monitoring quality is obtained.