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According to the observation to chilling injury symptoms of Lingwu Long Jujube, as well as the analysis to the enzyme activity related to the anti-adversity of plant in this paper, it is found that the disease will outbreak in 4-10 hours after low temperature pre-cooling, and the main symptoms include sinking semi-spherical dry spots and fibrosis of flesh. It is measured that the activity of polyphenol oxidase and phenylalnine ammonialyase in the diseased fruit is 0.34U and 101.689U separately, but the activity is 0.133U and 49.156U separately in healthy fruits, and there is a significant difference, but the difference of peroxidase is not significant. It laid the foundation for further research on relationship between chilling injury and metabolic pathway.

In order to accurately measure the surface roughness of the outer strands on aluminum conductor steel reinforced cable, two different methods are proposed to correct the error by the general method using light-section microscope. Comparing the images by staining method and angle amendment method for ACSR cable, it is found that the later is better than staining methods. The result conducts that angle amendment method using light-section microscope is suitable for measuring the surface roughness of the outer strands on ACSR cable.

The article analyzes the stability of agro-ecosystem’s productivity taking sustainable development theory and wave theory as guideline, conducted field study of the research area taking ** as research case based on analyzing ** yearly grain output, and establishes relatively complete, clear and easy accessible evaluation target system for agro-ecosystem productivity stability through analyzing the constraints of the stability in the area and making full use of current statistical data with combination with actual situation. The evaluation system is set to be 4 layers with 17 indices as per Delphi and AHP method and comprehensive weight of each index is determined. It analyzes the stability of agro-ecosystem productivity from the aspect of both time and space with current indices and standardized data using synthetic index method and volatility index calculation method.

Full face rock tunnel boring machine (TBM) plays an important role in boring rock of tunnel. The failure of disc cutter is the main reason leading to low efficiency of TBM. In this paper, analysis of force and motion for disc cutter are carried by using ABAQUS to study stress distribution and concentration in disc cutter and rocks. Influence of different rocks on stress in disc cutter is analyzed. By combination the failure modes of disc cutter and its stress distribution, methods of decreasing failures of disc cutter are presented. Wear resistance and service life of disc cutter are improved by matching the materials of disc cutters with rocks. The results are useful for structural optimization and strengthening treatment of material of disc cutter.

Disc cutter is the key part in Tunnel Boring Machine (TBM). Wear and tear of disc cutter is the main reason of low efficiency and high cost of this machine. Forces and deformations of disc cutter ring are foundation for its design and assembly. In this paper, the analysis of stress and deformation are carried to study their distribution; Wear mechanism of disc cutter ring is presented; modal analysis is carried to study the vibration of disc cutter ring. The results show the yield strength and rigidity of disc cutter ring is very high; disc cutter ring can avoid resonance and meet the engineering requirement. The results are very helpful for digital design of disc cutter ring used in different geology conditions.