Dry fig is a traditional healthy snack and has important economic value in a number of Mediterranean and Middle Eastern countries.Cultivars with no anthocyanin accumulation in the fruit peel are preferred for dry fig ...Dry fig is a traditional healthy snack and has important economic value in a number of Mediterranean and Middle Eastern countries.Cultivars with no anthocyanin accumulation in the fruit peel are preferred for dry fig production.R2R3-MYB transcription factors have promotive or repressive regulatory roles in plant anthocyanin biosynthesis.In this study,113 R2R3-MYB genes were identified in Ficus carica,3 of which were assigned to the S4 subfamily of flavonoid-biosynthesis repressors.FcMYB57 was further recruited as a candidate anthocyaninbiosynthesis repressor based on its sequence features and expression,which was significantly negatively correlated with that of anthocyanin-biosynthesis structural genes.Transient overexpression of FcMYB57 in strawberry totally inhibited fruit pigmentation and significantly increased fruit firmness.The metabolomic analysis confirmed a significant reduction in the contents of cyanidin-3-O-glucoside and pelargonidin-3-O-glucoside,as well as other flavonoids,and transmission electron microscopy revealed an increment in cell-wall thickness.Transcriptome analysis showed downregulation of anthocyanin-biosynthesis structural genes and upregulation of genes related to xylan synthesis.Yeast one-hybrid and dual luciferase assays demonstrated a negative regulatory effect of FcMYB57 on the promoter of FcUFGT3(UDP glucose-flavonoid 3-O-glcosyl-transferase).Yeast two-hybrid assay showed that FcMYB57 does not interact with FcbHLH42,3,14,MYC2,or FcTTG1,all of which have a previously identified or predicted role in flavonoid biosynthesis,however,interaction was detected with FcTPL(Topless),suggesting that FcMYB57 serves as an active repressor of anthocyanin biosynthesis.This is the first identification of an anthocyaninbiosynthesis repressor in fig,with a possible role in fig fruit quality.展开更多
First-principles calculations were employed to investigate the effects of microalloying element X(X=Yb,Er,Sc,Zr,Hf)interactions on the formation of L12 phases in aluminum conductor during aging.The evolution of L1_...First-principles calculations were employed to investigate the effects of microalloying element X(X=Yb,Er,Sc,Zr,Hf)interactions on the formation of L12 phases in aluminum conductor during aging.The evolution of L12-Al3X core−shell phase was examined.The analysis of interactions among solute atoms reveals a preference for elements to bind at the second nearest neighbors(2NN)distance.Particularly,Yb and Er are found to effectively attract elements to form clusters,with Sc showing a comparatively weaker attraction.Among the tri-solute combinations,Yb−Er−Zr exhibits the strongest mutual attraction.When the solute is segregated on the surface of phase,the segregation energy of remaining solute at the Al3X/α-Al interface increases gradually with decreasing the element diffusivity.Notably,the segregation energies at the Al3Yb/α-Al and Al3Er/α-Al interfaces are similar and relatively low.The values of segregation energies at the interfaces are primarily determined by the solute bonding with surrounding atoms.The interface energy of Al3X/α-Al is negatively correlated with the element diffusivity.The core−shell interfaces,such as Al3Er/Al3Hf,Al3Yb/Al3Hf,Al3Zr/Al3Er,and Al3Zr/Al3Yb,exhibit high interface stability,which is determined by the chemical bond strength between the atoms of microalloying elements at the interface.展开更多
Writing quality is often linked to how voice is represented in the text.In this study,drawing on the principles of Stratification and Realization from Systemic Functional Linguistics(SFL),together with the Sydney Sch...Writing quality is often linked to how voice is represented in the text.In this study,drawing on the principles of Stratification and Realization from Systemic Functional Linguistics(SFL),together with the Sydney School’s genre theory and the Engagement system within Appraisal Theory,we propose a framework for a more systematic,full text-paragraph-clause evaluation of authorial voice in L2 learners’argumentative writing,a stratified analysis from argument generic structure in the full text to Engagement interpersonal meaning expressed in paragraph and its lexicogrammatical realizations in clause.We demonstrate this framework through a detailed analysis of 14 high-quality,prize-winning argumentative writings written by Chinese undergraduates and released by Uchallenge,an annual English proficiency contest in China.The results confirm the significance of voice negotiation in producing sound argumentation.The students configured hybrid generic stages in their schematic structure and strategically employed Engagement lexicogrammatical resources across different stages of argumentation.This allowed them to successfully construct a strong authorial voice against a backdrop of multiple voices,despite some instances of implicit attribution and endorsement.Based on our analysis,we suggest that instructors guide L2 undergraduates in constructing their authorial voice by teaching argument genre conventions while allowing for structural variations,and by strengthening such understanding through critical reading of voice negotiation in expert writing.展开更多
This study compares the relative efficacy of the continuation task and the model-as-feedbackwriting (MAFW) task in EFL writing development. Ninety intermediate-level Chinese EFL learnerswere randomly assigned to a con...This study compares the relative efficacy of the continuation task and the model-as-feedbackwriting (MAFW) task in EFL writing development. Ninety intermediate-level Chinese EFL learnerswere randomly assigned to a continuation group, a MAFW group, and a control group, each with30 learners. A pretest and a posttest were used to gauge L2 writing development. Results showedthat the continuation task outperformed the MAFW task not only in enhancing the overall qualityof L2 writing, but also in promoting the quality of three components of L2 writing, namely, content,organization, and language. The finding has important implications for L2 writing teaching andlearning.展开更多
Simultaneously achieving high strength,adequate ductility,and low anisotropy remains challenging for additively manufactured medium-entropy alloys(MEAs),particularly without relying on post-processing.Here,a CO28Cr...Simultaneously achieving high strength,adequate ductility,and low anisotropy remains challenging for additively manufactured medium-entropy alloys(MEAs),particularly without relying on post-processing.Here,a CO28Cr18Ni42Al6Ti6 MEA was fabricated by laser-directed energy deposition(LDED),enabling effective in situ strengthening through nonequilibrium solidification and intrinsic thermal cycling.As a result,a hierarchical microstructure was developed,consisting of fine-grain clusters enriched with high-angle grain boundaries,coherent L12 nanoprecipitates,and distinctiveγ-Al2O3/β-Ti core-shell structures.Fine-grain clusters together with spatially distributed heterogeneities contributes to the reduced mechanical anisotropy.As a result,the alloy exhibited high strength while retaining good ductility,exhibiting yield strengths of 880±6.2 MPa and 850±7.2 MPa,ultimate tensile strengths of 1200±32.1 MPa and 1150±55.4 MPa,and fracture elongations of 19%±3.5%and 21%±5.5%along the building and scanning directions,respectively.The enhanced mechanical performance was attributed to multiscale strengthening arising from the synergistic L12 nanoprecipitates and core-shell structures,which impeded dislocation motion across multiple length scales while accommodating interfacial strain,thereby sustaining work hardening and retaining ductility.展开更多
基金supported by the key research project for fig development of Weiyuan County(Grant No.1002-69199007),China.
摘要Dry fig is a traditional healthy snack and has important economic value in a number of Mediterranean and Middle Eastern countries.Cultivars with no anthocyanin accumulation in the fruit peel are preferred for dry fig production.R2R3-MYB transcription factors have promotive or repressive regulatory roles in plant anthocyanin biosynthesis.In this study,113 R2R3-MYB genes were identified in Ficus carica,3 of which were assigned to the S4 subfamily of flavonoid-biosynthesis repressors.FcMYB57 was further recruited as a candidate anthocyaninbiosynthesis repressor based on its sequence features and expression,which was significantly negatively correlated with that of anthocyanin-biosynthesis structural genes.Transient overexpression of FcMYB57 in strawberry totally inhibited fruit pigmentation and significantly increased fruit firmness.The metabolomic analysis confirmed a significant reduction in the contents of cyanidin-3-O-glucoside and pelargonidin-3-O-glucoside,as well as other flavonoids,and transmission electron microscopy revealed an increment in cell-wall thickness.Transcriptome analysis showed downregulation of anthocyanin-biosynthesis structural genes and upregulation of genes related to xylan synthesis.Yeast one-hybrid and dual luciferase assays demonstrated a negative regulatory effect of FcMYB57 on the promoter of FcUFGT3(UDP glucose-flavonoid 3-O-glcosyl-transferase).Yeast two-hybrid assay showed that FcMYB57 does not interact with FcbHLH42,3,14,MYC2,or FcTTG1,all of which have a previously identified or predicted role in flavonoid biosynthesis,however,interaction was detected with FcTPL(Topless),suggesting that FcMYB57 serves as an active repressor of anthocyanin biosynthesis.This is the first identification of an anthocyaninbiosynthesis repressor in fig,with a possible role in fig fruit quality.
基金supported by the National Natural Science Foundation of China(No.52274403)。
摘要First-principles calculations were employed to investigate the effects of microalloying element X(X=Yb,Er,Sc,Zr,Hf)interactions on the formation of L12 phases in aluminum conductor during aging.The evolution of L12-Al3X core−shell phase was examined.The analysis of interactions among solute atoms reveals a preference for elements to bind at the second nearest neighbors(2NN)distance.Particularly,Yb and Er are found to effectively attract elements to form clusters,with Sc showing a comparatively weaker attraction.Among the tri-solute combinations,Yb−Er−Zr exhibits the strongest mutual attraction.When the solute is segregated on the surface of phase,the segregation energy of remaining solute at the Al3X/α-Al interface increases gradually with decreasing the element diffusivity.Notably,the segregation energies at the Al3Yb/α-Al and Al3Er/α-Al interfaces are similar and relatively low.The values of segregation energies at the interfaces are primarily determined by the solute bonding with surrounding atoms.The interface energy of Al3X/α-Al is negatively correlated with the element diffusivity.The core−shell interfaces,such as Al3Er/Al3Hf,Al3Yb/Al3Hf,Al3Zr/Al3Er,and Al3Zr/Al3Yb,exhibit high interface stability,which is determined by the chemical bond strength between the atoms of microalloying elements at the interface.
摘要Writing quality is often linked to how voice is represented in the text.In this study,drawing on the principles of Stratification and Realization from Systemic Functional Linguistics(SFL),together with the Sydney School’s genre theory and the Engagement system within Appraisal Theory,we propose a framework for a more systematic,full text-paragraph-clause evaluation of authorial voice in L2 learners’argumentative writing,a stratified analysis from argument generic structure in the full text to Engagement interpersonal meaning expressed in paragraph and its lexicogrammatical realizations in clause.We demonstrate this framework through a detailed analysis of 14 high-quality,prize-winning argumentative writings written by Chinese undergraduates and released by Uchallenge,an annual English proficiency contest in China.The results confirm the significance of voice negotiation in producing sound argumentation.The students configured hybrid generic stages in their schematic structure and strategically employed Engagement lexicogrammatical resources across different stages of argumentation.This allowed them to successfully construct a strong authorial voice against a backdrop of multiple voices,despite some instances of implicit attribution and endorsement.Based on our analysis,we suggest that instructors guide L2 undergraduates in constructing their authorial voice by teaching argument genre conventions while allowing for structural variations,and by strengthening such understanding through critical reading of voice negotiation in expert writing.
摘要This study compares the relative efficacy of the continuation task and the model-as-feedbackwriting (MAFW) task in EFL writing development. Ninety intermediate-level Chinese EFL learnerswere randomly assigned to a continuation group, a MAFW group, and a control group, each with30 learners. A pretest and a posttest were used to gauge L2 writing development. Results showedthat the continuation task outperformed the MAFW task not only in enhancing the overall qualityof L2 writing, but also in promoting the quality of three components of L2 writing, namely, content,organization, and language. The finding has important implications for L2 writing teaching andlearning.
基金supported by the National Natural Science Foundation of China(Grant Nos.52501037,52371025,and 52371106)。
摘要Simultaneously achieving high strength,adequate ductility,and low anisotropy remains challenging for additively manufactured medium-entropy alloys(MEAs),particularly without relying on post-processing.Here,a CO28Cr18Ni42Al6Ti6 MEA was fabricated by laser-directed energy deposition(LDED),enabling effective in situ strengthening through nonequilibrium solidification and intrinsic thermal cycling.As a result,a hierarchical microstructure was developed,consisting of fine-grain clusters enriched with high-angle grain boundaries,coherent L12 nanoprecipitates,and distinctiveγ-Al2O3/β-Ti core-shell structures.Fine-grain clusters together with spatially distributed heterogeneities contributes to the reduced mechanical anisotropy.As a result,the alloy exhibited high strength while retaining good ductility,exhibiting yield strengths of 880±6.2 MPa and 850±7.2 MPa,ultimate tensile strengths of 1200±32.1 MPa and 1150±55.4 MPa,and fracture elongations of 19%±3.5%and 21%±5.5%along the building and scanning directions,respectively.The enhanced mechanical performance was attributed to multiscale strengthening arising from the synergistic L12 nanoprecipitates and core-shell structures,which impeded dislocation motion across multiple length scales while accommodating interfacial strain,thereby sustaining work hardening and retaining ductility.