Effects of Ru content on phase transformation and compression property of cast TiAl alloys

Ruthenium(Ru)is a promising element to heighten the comprehensive mechanical properties of TiAl alloys.In the present study,the phase transformation during the cooling of Ti-47Al-2Cr-2Nb-xRu(x=0,0.1,0.5,1.0,at.%)alloys was investigated.The results show that Ru tends to segregate in the interdendritic region during solidification,and therefore,refines the as-cast microstructure of the alloys.As aβ-stabilizer,Ru does not induce a novel solidification reaction but maintains the peritectic reaction of L+β→α.An excessive Ru content would cause the formation of(γ+τ1+B2)and(α+γ+τ1+B2)phase regions below 1,250°C.The precipitation ofτ1-containing mixture is attributed to the Ru-segregation,which inhibits the reaction ofα→γand facilitates the formation of B2 phase.The discontinuous coarsening ofγphase and blockτ1 phase formed alternately in a manner of analogous eutectoid decomposition within B2 phase.In addition,the effect of Ru content on compression property of the alloys was studied.The yield strength increases up to 427 MPa at 800°C with the addition of 1.0at.%Ru,which is mainly due to the solution strengthening effect of Ru.

Values,properties and utility of different parts of Moringa oleifera:An overview

Moringa oleifera is one of the most widespread species belonging to family Moringaceae. Almost each part of this tree has enormous properties in nutrition, medicine, or other industrial purposes. This review mainly introduces nutritional ingredients, bioactive compounds, applications, and potentials of this tree,including leaves, seeds, pods, flowers, root barks, and gum, in order to bring convenience to industries and researchers all over the world focusing on each part of this amazing plant. Moreover, the review also analyzes the current application situation of M. oleifera in China. After summarizing the recent researches of M. oleifera, we conclude that most current researches focus on the leaves and seeds of this plant, and the most concerned property of M. oleifera is the antioxidant ability. However, the molecular mechanisms under its multiple properties need further studies.

Authenticity Survey of Cuscutae Semen on Markets Using DNA Barcoding

Objective Using authentic raw herbal materials is fundamental to herbal medicine quality. Cuscuta chinensis and C. australis are two important species of Cuscutae Semen recorded in Chinese Pharmacopoeia. Due to having tiny bodies of seeds, it is extremely difficult to differentiate them from adulterants and closely related species by morphologic characteristics, leading to serious safety problems. Methods In this study, we developed a fast and efficient method to identify Cuscutae Semen on the market. First, a total of 207 ITS2 sequences representing 45 related species of Cuscutae Semen were collected to construct a standard DNA barcode database, then 33 commercial samples purchased from markets were analyzed by BLAST, and Neighbor-joining tree was used to verify the efficacy of the database. Results The percentage of counterfeits and adulterants in the 33 commercial samples were up to 69.7%, and only 10 commercial products were found to be genuine. The adulterated species included 11 species （Amaranthus hybridus, Brassica carinata, Brassica juncea var. megarrhiza, Chenopodium album, Corispermum heptapotamicum, Cuscuta alata, Cuscuta japonica, Cuscuta monogyna, Foeniculum vulgare, Glycine max, and Medicago sativa）. Conclusion DNA barcoding is a fast and efficient method to identify Cuscutae Semen on the market.

Progress on research of tissue culture of Bletilla striata

Rhizoma Bletillae is in high demand as a traditional Chinese medicine, and the natural resources have been severely damaged due to excessive exploitation. Because Bletilla striata seeds are small and have no endosperm, the seed germination rate is low in natural conditions. Traditional division propagation could not meet the demands of large-scale cultivation. Tissue culture can provide many seedlings in a short time and is more effective and convenient than other methods. Most studies on tissue culture of B. striata selected seeds as explants. This review summarized the processes of the aseptic seed germination pathway. It included such stages as seed germination, proliferation of clusters of buds, induction of root- ing and transplanting of seedlings. Influential factors as well as optimum combination and concentration of the plant growth regulators of each stage were also summarized. The further research on tissue culture of B. striata was also prospected.

Microstructure evolution and mechanical properties of a novelγ’phase-strengthened Ir-W-Al-Th superalloy

The present work introduces a novelγ’phasestrengthened Ir-W-Al-Th superalloy for ultrahigh-temperature applications.First,the as-cast microstructure and phase transformation of Ir-13 W-6 Al-0.15 Th(at%)alloy during solid solution and aging were investigated.Phase transformation was observed during heat treatment.The primaryγ’phase disappeared via the redissolution ofγ’→γat 1800℃.The recrystallization took place at 1450℃and very fine equiaxedγ’/γgrains formed after240 h.The cold-rolled microstructure indicated that the room-temperature c phase was brittle and cracks mainly emerged along grain boundaries.Ir-13 W-6 Al-0.15 Th alloy exhibited a higher nanohardness than other Ir-based superalloys and pure Ir,which can be attributed to the solid solution and precipitation(γ’)strengthening.In addition,the as-cast Ir-13 W-6 Al-0.15 Th alloy shows a medium room-temperature compressive yield strength and good ductility.

Identification of flower herbs in Chinese pharmacopoeia based on DNA barcoding

Objective: Flower herbs are an important category of traditional Chinese medicinal materials, some of which are used as healthcare tea in folk. However, the increasing adulteration of medicinal herbs is threatening consumer safety. The adulteration of flower herbs and their healthcare tea products in the market were investigated.Methods: A total of 33 flower herb samples from several retail pharmacies in China were randomly collected and 27 flower healthcare tea samples were purchased online. They were identified using ITS2-based Traditional Chinese Medicine Database(TCMD). Additionally, Lonicerae Japonicae Flos and the adulterants were compared in the ITS2 secondary structures.Results: There were one adulterant(Inulae Flos) in flower herb materials and eight adulterants in healthcare tea samples. Inula linariifolia was an adulterate species of Inulae Flos, Robinia pseudoacacia was of Sophorae Flos, and Lonicera macranthoides was of Lonicerae Japonicae Flos. Sophorae Flos and Lonicerae Japonicae Flos were two healthcare tea products with high adulteration rates.Conclusion: The TCMD is powerful tool to identify flower herbs and the adulterants that frequently occurred in the flower herb market, especially online shops.