The molten mixtures of alkali metal fluorides and aluminum fluoride are applied as aluminum electrolytes or brazing fluxes.However,the presence of Al2F-7^-in such molten systems is disputed.In the present study,MF-AlF...The molten mixtures of alkali metal fluorides and aluminum fluoride are applied as aluminum electrolytes or brazing fluxes.However,the presence of Al2F-7^-in such molten systems is disputed.In the present study,MF-AlF3(M=K,Cs)systems with molar ratios<1 were studied by in-situ Raman spectroscopy and molecular simulation.The results show that,in addition to AlF6^(3-),AlF5^(2-),and AlF4^-,the systems also contained Al2F-7^-.The characteristic bands in the Raman spectra belonging to Al2F-7^-were located at about 225 cm^-1,315 cm^-1,479 cm^-1,and 720 cm^-1.There are two possible structures of Al2F-7^-,which belong to the D3d and D3hpoint groups.Both of these structures are linear,and their single-point energies were found to differ by only 0.31 kcal/mol.展开更多
In terms of reel-lay installation in deep water, studies on the pipeline during the process of tensioning have been completed based on theories of risk and reliability analysis and Ergonomics. Qualitative risk results...In terms of reel-lay installation in deep water, studies on the pipeline during the process of tensioning have been completed based on theories of risk and reliability analysis and Ergonomics. Qualitative risk results, including minimum cut sets, structural importance and probability expression of system failure, are obtained from fault tree analysis. Also, quantitative risk results, mainly consisting of failure probability and reliability index of pipeline plastic deformation, are worked out through Monte Carlo simulation. Simultaneously, scientific suggestions based on Ergonomics are provided. Conclusions drawn from this paper can, to some extent, provide certain references for reel-lay installation in deep water.展开更多
To improve the low transplanting efficiencies and simplify the complex structures of current automatic transplanters,a mechanical high-speed transplanter for picking plug seedlings that is suitable for planting on pla...To improve the low transplanting efficiencies and simplify the complex structures of current automatic transplanters,a mechanical high-speed transplanter for picking plug seedlings that is suitable for planting on plastic filmswas designed.Themain components were an automatic seedling picking systemand a basket-type planting system,whichwere used for the following processes:automatic picking,planting,soil covering,and suppression of plug seedlings.The performance test was performed on the automatic transplanter with 60-day-old pepper seedlings.The transplanting efficiency was tested at speeds of 40,60,90,and 120 plants·min−1.The results showed that the coefficient of variation(CV)of the plant spacing and the missed transplanting rate increased with the planting frequency,whereas the qualified rate of planting perpendicularity and the qualified rate of planting decreasedwith the increase in the planting frequency.All planting indicesmet the JB/T 102912013 standards.The results of this study showed that the auto-transplanter could performhigh-speed transplanting on the basis of completing the following functions:automatic picking,planting,soil covering,and suppression of plug seedlings.展开更多
基金the National Natural Science Foundation of China(grant no.51474060)the National Key R&D Program of China(grant no.2017 YFC0805100)+1 种基金the National Natural Science Foundation of Liaoning Province(China)(grant no.2019-MS-129)the Fundamental Research Funds for the Central Universities of China(grant no.N162502002).
文摘The molten mixtures of alkali metal fluorides and aluminum fluoride are applied as aluminum electrolytes or brazing fluxes.However,the presence of Al2F-7^-in such molten systems is disputed.In the present study,MF-AlF3(M=K,Cs)systems with molar ratios<1 were studied by in-situ Raman spectroscopy and molecular simulation.The results show that,in addition to AlF6^(3-),AlF5^(2-),and AlF4^-,the systems also contained Al2F-7^-.The characteristic bands in the Raman spectra belonging to Al2F-7^-were located at about 225 cm^-1,315 cm^-1,479 cm^-1,and 720 cm^-1.There are two possible structures of Al2F-7^-,which belong to the D3d and D3hpoint groups.Both of these structures are linear,and their single-point energies were found to differ by only 0.31 kcal/mol.
文摘In terms of reel-lay installation in deep water, studies on the pipeline during the process of tensioning have been completed based on theories of risk and reliability analysis and Ergonomics. Qualitative risk results, including minimum cut sets, structural importance and probability expression of system failure, are obtained from fault tree analysis. Also, quantitative risk results, mainly consisting of failure probability and reliability index of pipeline plastic deformation, are worked out through Monte Carlo simulation. Simultaneously, scientific suggestions based on Ergonomics are provided. Conclusions drawn from this paper can, to some extent, provide certain references for reel-lay installation in deep water.
基金supported by the National Key Research Program of China(2017YFD0700800)the National Natural Science Foundation of China(50905153,51565059)+1 种基金Autonomous Region Key Research Projects(2018B01001-3)Autonomous Region Tianshan Youth Program(2017Q018).
文摘To improve the low transplanting efficiencies and simplify the complex structures of current automatic transplanters,a mechanical high-speed transplanter for picking plug seedlings that is suitable for planting on plastic filmswas designed.Themain components were an automatic seedling picking systemand a basket-type planting system,whichwere used for the following processes:automatic picking,planting,soil covering,and suppression of plug seedlings.The performance test was performed on the automatic transplanter with 60-day-old pepper seedlings.The transplanting efficiency was tested at speeds of 40,60,90,and 120 plants·min−1.The results showed that the coefficient of variation(CV)of the plant spacing and the missed transplanting rate increased with the planting frequency,whereas the qualified rate of planting perpendicularity and the qualified rate of planting decreasedwith the increase in the planting frequency.All planting indicesmet the JB/T 102912013 standards.The results of this study showed that the auto-transplanter could performhigh-speed transplanting on the basis of completing the following functions:automatic picking,planting,soil covering,and suppression of plug seedlings.
