We produce hexagonal steel bar by cold drawing through hex mould from hot rolled steel round bar. In this way, hexagonal steel bar has precision size tolerance, better surface and sharp corner radius. Except cold drawn hexagonal steel bar, we can also produce heat treated hexagonal steel bar. For example, annealed hexagonal steel bar, qhenched and tempered Q&T hexagonal steel bar. After heat treatment, hexagonal steel bar mechanical properties will be better or higher. For heat treated hexagonal steel bar, straightness is very important. We have fine straightening machine to do straightening to keep good straightness. Hexagonal Steel Bar,Hex Steel Bar,Hexagon Steel Bar,Hexagonal Rod Steel,12L14 cold drawn hexagonal steel bar SHANDONG LE REN SPECIAL STEEL CO., LTD. , https://www.js-luggagecarts.com
The leaf area meter found that with the continuous growth of spring wheat, the coefficient of variation of the coverage decreased, while the coefficient of variation of the leaf area index increased first and then decreased. Spring wheat leaf area index and coverage have time stability characteristics. The sowing- tilling stage is preceded by headwater irrigation. The coverage of spring wheat at this stage has a significant effect on the stability of the whole growth period. In contrast, the leaf area index at this stage is stable to the entire growth period. The effect is not obvious.
There is a significant relationship between leaf area index and coverage: when the spring wheat coverage is high, the corresponding leaf area index is also larger, and the spring wheat leaf area index has a significant exponential relationship with coverage, analyzed by the leaf area meter, The fitting equation reaches a significant level. When the leaf area index exceeds a certain limit, the coverage tends to be saturated, and the spring wheat coverage and leaf area index change similarly with time, but the variation trend of the coefficient of variation of the two is very different.
The spatial correlation distance between spring wheat leaf area index and coverage in the sowing-fed stage (before headwater irrigation) is the largest. The observational data at this stage have a great influence on the spatial variability of the leaf area index and coverage throughout the growth period. Leaf area measurement index and coverage in other fertility stages are relatively stable. The leaf area index growth model dynamically unifies the leaf area at different growth stages in space and is more adaptable than before.
The measurement of leaf area meter leaf area index and coverage are important indicators to measure the growth status of spring wheat, but studies have shown that only the vegetation coverage as an evaluation index can not fully reflect the other characteristics of various vegetation conditions, such as water and soil Keep differences and so on. In practice, the leaf area index not only reflects the structure, distribution density, and biomass information of the vegetation, but also the leaf area meter measuring equipment is convenient and fast. Usually more is the leaf area index as an important indicator of wheat growth.