A Comparative Study of Flavonoid Water-Ethanol Extraction Process in Planted Trollius Chinensis

With rutin standard sample as the comparison, flavonoid extraction rate as an indicator, UV-2450 ultraviolet visible light spectrophotometer to measure flavonoid content in planted Trollius chinensis through orthogonal experiment, this experiment optimizes process condition of flavonoid in Trollius chinensis through water extraction and ethanol extraction. The result shows that flavonoid extraction rate of Trollius chinensis through ethanol extraction method is obviously higher than water extraction, and the optimal extraction process condition is： ethanol concentration is 75%, extraction time is 90min, extraction times are 3, and fluid material ratio is 20：1.

A Comparative Study of Process Parameter Optimization and Process of Flavonoid in Planted Trollius Chinensis through Backflow Method, Ultrasonic Wave Method and MicrowaveMethod

It takes flavonoid extraction rate as indicator and adopts the method of orthogonal experiment to study process of total flavonoid in Trollius chinensis through ultrasonic wave assisted extraction, microwave assisted extraction and backflow extraction, as well as optimization of process parameter. The result indicates that in terms of extraction efficiency, microwave extraction method is better than ultrasonic radiation extraction method, which is better than backflow extraction method. Optimal process parameter through backflow extraction is： backflow temperature 60℃, fluid material ratio 1：20, ethanol density 65%, backflow time 60min; optimal process parameter through ultrasonic wave assisted extraction is： ultrasonic radiation temperature 70℃, fluid material ratio 1：20, ethanol density 65%, ultrasonic wave radiation time 45rain; optimal process parameter of microwave assisted extraction is： microwave radiation temperature 60℃, fluid material ratio 1：20, ethanol density 75%, microwave radiation time 45min.

Microstructure evolution and phase transformation of the mushy zone in a quenchedβ-solidifying TiAl alloy

This study investigates the phase constitutions and transformations that occur in the mushy zone and in the adjacent phase fields of a directionally solidified Ti-44Al-8Nb-1Cr alloy via quenching technique.The results indicate that the mushy zone consists of unmeltedβdendrites and interdendritic liquid,whose formation can be attributed to the difference in melting point aroused by local heterogeneity in solutecontent.Theβdendrite is composed of numerous subgrains with various orientations.During quenching,theβdendrite transforms into Widmanstättenαvia a precipitation reaction,owing to the decreasing cooling rate caused by heat transfer from the surrounding liquid.Additionally,after quenching,the interdendritic liquid is transformed intoγplates.Within the singleβphase field and the lower part of the mushy zone,a massive transformation ofβtoγoccurs.Conversely,in theβ+αphase field,bothβandαphases are retained to ambient temperature.During the heating process,the transformation ofα→βgives rise to the formation ofβvariants,which affects the orientation ofβdendrites in the mushy zone.The growth kinematics of theα→βtransformation was elucidated,revealing the preferential growth directions of111and112forβvariants.Furthermore,this study presents an illustration of the formation process of the mushy zone and the microstructural evolution during the heating and quenching process.

Simultaneous enhancement of strength and ductility in high Nb-TiAl by Si alloying

1.Introduction TiAl alloys are lightweight and high-temperature-resistant structural materials having applicability in automotive and aerospace applications owing to their low density and excellent high-temperature properties[1-3].High-Nb-containing TiAl(High Nb-TiAl)alloys are considered as a new generation of TiAl alloys for applications at higher service temperatures[4-6].Components of TiAl alloys that have achieved long-term stability in the industry are mainly manufactured by casting,which is the most economical method[7-9].However,the mechanical properties of these com-ponents are limited at room temperature(RT),significantly hinder-ing their broad applications[7,10-12].

Deformation twinning in equiaxed-grained Fe-6.5 wt.%Si alloy after rotary swaging

Tensile behavior of an equiaxed-grained Fe-6.5 wt.%Si alloy,which was deformed intoφ6 mm bar by hot rotary swaging,was investigated at various temperatures(300–400℃)and stretching rates(0.42–1 mm/min).The results revealed an enhancement in the intermediate-temperature tensile ductility after heat treatments.Deformation twinning was found in the equiaxed-grained Fe-6.5 wt.%Si bars during the tensile test,and heat treatments can enhance the deformation twinning.More twins can be observed in the necking areas than other regions.The high Schmid factor values above 0.4 after heat treatments demonstrated that deformation twinning can easily occur in the equiaxed-grained Fe-6.5 wt.%Si alloy.Higher deformation temperatures,higher strain rates,and larger degree of order suppressed the formation of deformation twinning,while the grain sizes had little effect on the deformation twinning.The twinning stress of the Fe-6.5 wt.%Si alloy increased with the increasing grain size,which did not agree with the Hall–Petch type relationship.The deformation twinning resulted in the improved ductility of the Fe-6.5 wt.%Si alloy.