The drawing process of a high strength steel part without blank holder force was numerically simulated based on Dynaform. In present investigation, the drawing velocity and velocity profile motion of punch was studied by simulating the drawing operation of high strength steel part. The results show that restricting drawing velocity and controlling velocity profile motion of punch could all reduce the spring back. The measure of restricting drawing velocity could reduce non-pressure forming spring back about 31% and Trapezoidal motion mode of punch is the most beneficial to reduce spring back.
This paper introduced the preparation of butylene fipronil-loaded microcapsules with oppositely charged chitosan and sodium lignosulfonate as shell materials. It summed up the performance, preparation methods of microcapsules and sketched the application status of layer-by-layer self-assembly. The whole progress of the preparation was controlled by measuring the change of the Zeta potential and the morphology of microcapsules was characterized by microscope and SEM. Entrapment efficiency and slow release performance of the microcapsule were determined as measurement index. The results of experiment showed that the surface of the microcapsules was rougher than the butylene fipronil particles. With the increasing layer number of assembly, the entrapment efficiency reduced while the slow release performance increased. After encapsulation, the photodegradation rate of butylene fipronil under the UV decreased obviously. Results showed that the condition of preparation was the best when NaCl with the concentration of 0.5 mol/L and PH of 5.0.
In the present investigation, bio-inorganic composite, which was synthesized with chitosan and hydroxyapatite by adding zinc(II) ions, have been prepared by precipitation method and was characterized by Fourier Transform infrared (FTIR) spectroscopy and energy dispersive X-ray analyzer (EDXA). Then, the composite was used for removal of Cobalt(II) from synthetic aqueous solution. The effects of initial pH, contact time, kinetic and isothermal adsorption were studied in detail using batch adsorption at different temperature. The results showed that Cobalt(II) ions can be efficiently removed and also demonstrated that the kinetic data were best described by the pseudo-second-order model (R2>0.99), While thermodynamic investigation of Cobalt(II) ions adsorption by zinc(II) doping Chitosan/hydroxyapatite (Zn-HAPCS) composite confirmed a spontaneous adsorption. Further investigations demonstrated that the adsorption pattern fitted well with Langmuir model (R2 > 0.99), but less-satisfied with Freundlich model (R2 < 0.95).
We previously determined that the cyclase inhibitor tripropylamine (TPA) significantly enhances lycopene accumulation in Blakeslea trispora. To elucidate the mechanism of TPA-enhanced lycopene accumulation, the untargeted metabolome of B. trispora treated with TPA was analyzed by UHPLC-Q-TOF/MS. Forty-two differential metabolites were identified, of which 15 significantly differential metabolites meeting the following parameters were screened: variable importance for the projection > 1, P < 0.05, and fold change > 1.5. The down-regulated metabolites were mainly cyclic dipeptides, bacteriostatic compounds, and lipids, while the up-regulated metabolites were mainly unsaturated fatty acid. Furthermore, the bacteriostatic ability was poor, the extracellular and intracellular pH levels were high, and hyphae with vesicles were swollen locally in B. trispora after treatment with TPA. Our data suggest that the TPA enhances lycopene accumulation not only by inhibiting the cyclization of β-carotene but also by down-regulating cyclic dipeptides for quorum sensing; up-regulating unsaturated fatty acids, 1-palmitoyl-2-hydroxy-sn-glycero-3-phosphoethanolamine, and 4-hydroxybenzoate and down-regulating choline, resulting in locally swelling mycelium with vacuoles; and down-regulating bacteriostatic metabolites for metabolic flux redistribution.
In this work, Numerical simulations based on finite element method have been carried out to study the effect of important process parameters on formability of AA5182 alloy sheets. The blank holder force between 0.5KN and 3KN and friction coefficient(μ) between 0.05 and 0.20, which resulted in successful drawing, was evaluated. Maximum percentage thinning has always been obtained at the conjunction of corner and bottom. The maximum thinning rate was nearly 20% for a maximum holder force of 3KN. Friction coefficient simulations are shown that as friction coefficient increasing, the thinning rate becomes larger and low friction coefficient is beneficial to the sheet forming.
The mechanical properties and microstructure of plastic mould steel with the microstructure of martensite and bainite -martensite (ByM) were investigated in detail. The results show that the aircooled ByM possesses a better combination of strength and toughness compared with water-quenched full martensite after tempering within some intermediate temperature range. A mixed microstructure of ByM retards the softening of the steel during tempering and also retards the tempered martensite embrittlement onset temperature. The stable retained austenite (SRA) in ByM improved the toughness of the steel after tempering at intermediate temperature range.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.