Effect of Different Proportions of Wolffia on Growth of Procambarus clarkia in Two Community Scales

[Objective] This study aimed to examine the effect of different proportions of Wolffia on the growth of Procambarus clarkia in 2 kinds of community scales. [Method] Six proportions of baits mixed by watermeal and commercial feed (0, 20%, 40%, 60%, 80%, and 100%) were designed to feed the Procambarus clarkia juveniles in 2 community scales to research the growth situation of the crayfish in different mixed baits. The growth differences between the minimal community and the larger community of crayfish in the same proportion of Wolffia were compared. [Result] The growth situations of crayfish in the 2 community scales at different proportions of watermeal were as follows: the body length was the longest in 60% watermeal group, and shortest in the pure watermeal group; the regularity was the best in the 20% watermeal group; no matter the minimal community or the larger community, there was no significant difference in the survival rate between different watermeal proportions. The growth situations of crayfish in the 2 community scales at specific proportion of watermeal were: the average body length of the minimal community was significantly greater than the larger community, and the survival rate also greater than the latter one, but the difference was not significant. [Conclusion] Considering all kinds of index such as growth, survival rate, regularity, the appropriate proportion of the baits mixed by watermeal and commercial feed is 40% to 60%; big community scale has significant inhibition on growth of crayfish, thus, there should be barriers when cultivating Procambarus clarkia juvenile.

Influence of New Compound Admixture on Shotcrete Performance

To analyze the influence of new compound admixture on shotcrete performance, the ordinary Portland cement pr425 was used as matrix components. The optimum proportion of admixture was obtained by analyzing the influence of content on cement setting time and compressive strength. The microstructure of cement test block and the mechanism of reducing dust of composite macromolecule admixture were analyzed by scanning electron microscopy and infrared spectroscopy. It was shown that the ratio of polyacrylic acid was 0.02%. The ratio of J85 accelerator was 5%. The ratio of bentonite was 4.5% in composite admixture. The most optimal content of admixture in the slurry was 7%. The compound coagulant formed by additive together with C3A, C4AF which provided nucleation for hydration and crystallization of C3S and C3S, and played an active role to promote the activity of the mineral admixture in cement, and increased the elastic modulus of C-S-H gel and accelerated the hydration process of portland cement. Bentonite and polyacrylic acid promote the wettability, cohesiveness and workability of cement paste in the process of hydration. The formation of cement test block gel was even. The interface between the matrix phase and the aggregate phase was not obvious which ensured the matching between the matrix and the aggregate phase. The addition of bentonite formed hydrogen bonds in cement paste and improved the cohesiveness of the system. The J-85 accelerator promoted the combination of aluminate and gypsum which hindered the formation of calcium carbide around the cement particles which made cement rapid condensation. Polyacrylic acid mainly changed the strength of hydroxyl absorption peak in cement paste to improve the initial strength of cement test block. The addition of new admixtures promoted the process of cement hydration to be more thorough and affected the later strength development of concrete by affecting the formation of calcium carbonate stone.

JYPB2.0—A new composition adjust-ment processing system of metal melting

The new system contains all the independent variables, setting the ultimate objective function groups,installing the complete operating program chain and establishing the accurate mathematical model. The new systemproduces the ultimate objective function group- Optimum Proportion Scheme through the processing of the elevenoperating main programs such as Optimization Program, etc. and revising of three operating auxiliary programssuch as Elimination Program, etc. which is locked by the intermediary objective function group. The setting of thecomplete database system provides the full-service for the customers' smelting production. It is generally applicablefor all the varieties of alloys and raw materials. Its customized features can fulfill the actual needs of users. These arethe advantages of the new composition adjustment processing system of metal melting- JYPB2.0.