Monocrystalline Cu exhibits excellent electrical and signal-transmission properties due to its absence of grain boundaries,making it a critical material for the production of micro-machinery and micro-components;howev...Monocrystalline Cu exhibits excellent electrical and signal-transmission properties due to its absence of grain boundaries,making it a critical material for the production of micro-machinery and micro-components;however,achieving ultrahigh precision and ultralow damage machining of functional devices using traditional techniques such as grinding and polishing is extremely challenging.Consequently,nanocutting has emerged as an efficient means to fabricate monocrystalline materials with complex surface characteristics and high surface integrity.Nevertheless,the macroscopic cutting theory of metal materials cannot be applied to nanocutting.Accordingly,in this paper,both simulations and experiments were conducted to examine the chip deformation mechanisms of monocrystalline Cu.First,large-scale molecular dynamics(MD)simulations were conducted to gain a comprehensive understanding of the deformation behavior during nanocutting.This included examining the influencing factors and the variation patterns of the chip deformation coefficient,cutting force,and minimum cutting thickness.Subsequently,nanocutting experiments were performed using a specially designed nanocutting platform with high-resolution online observation by scanning electron microscopy.The experimental results served to verify the accuracy and reliability of theMDmodeling,as they exhibited excellent consistency with the simulated results.Although this work considered monocrystalline Cu,it is believed that the elucidated chip deformation mechanisms could also be applied to other face-centered-cubic metals.These results are of great value for advancing the understanding of the mechanisms of ultraprecision cutting.展开更多
Inducing fruit resistance helps control postharvest diseases effectively.The early signal response plays a crucial role in the subsequent series of fruit resistance reactions.Pichia kudriavzevii was identified as the ...Inducing fruit resistance helps control postharvest diseases effectively.The early signal response plays a crucial role in the subsequent series of fruit resistance reactions.Pichia kudriavzevii was identified as the effective biological elictior for enhancing induced resistance of cherry tomato fruit in this study and the early response signal and its regulatory mechanism subsequently was investigated by RNA sequencing analysis and reverse transcription quantitative real-time PCR(RT-qPCR).Profile trend analysis revealed that,in the early stages of induction(0.5 h and 1 h),the genes related to fruit Ca^(2+)signalling(CML1,CDPK4,CIPK1,and GLR2.9),MAPK signalling(MPK9),the ethylene signalling pathway(ETR2 and EFR1B),and the phenylpropane biosynthesis pathway(PAL5 and 4CL6)respond first.Moreover,the transcription of glutathione pathway genes(GSTU7 and HSP26-A)was upregulated to maintain the balance of reactive oxygen species(ROS)in fruits.After 24 h of induction by P.kudriavzevii,secondary metabolites such as lignin and terpenes in the phenylpropanoid biosynthesis pathway(4CL2,4CL6,CCOAOMT,HMG2,and FPS1),as well as salicylic acid(SA),jasmonic acid(JA),and brassinosteroid(BR)signalling pathways in the plant hormone signalling pathway(TGA1A,TGA9,GH3.5,BAK1,CURL1),were activated.Additionally,upstream genes(PAL5 and 4CL6)in the phenylpropanoid pathway directly activate downstream gene transcription,promoting the production of resistance-related metabolites.P.kudriavzevii induces the activation of early signals such as Ca^(2+) signalling,MAPK signalling,and ethylene signalling,which in turn promote the activation of secondary metabolism and JA,BR,and SA hormone signalling in fruits to regulate resistance responses in fruits.展开更多
基金support of the National Natural Science Foundation of China(Grant No.51805371)the Innovation and Entrepreneurship Training Program of Tianjin University of Commerce(Grant No.202310069067).
文摘Monocrystalline Cu exhibits excellent electrical and signal-transmission properties due to its absence of grain boundaries,making it a critical material for the production of micro-machinery and micro-components;however,achieving ultrahigh precision and ultralow damage machining of functional devices using traditional techniques such as grinding and polishing is extremely challenging.Consequently,nanocutting has emerged as an efficient means to fabricate monocrystalline materials with complex surface characteristics and high surface integrity.Nevertheless,the macroscopic cutting theory of metal materials cannot be applied to nanocutting.Accordingly,in this paper,both simulations and experiments were conducted to examine the chip deformation mechanisms of monocrystalline Cu.First,large-scale molecular dynamics(MD)simulations were conducted to gain a comprehensive understanding of the deformation behavior during nanocutting.This included examining the influencing factors and the variation patterns of the chip deformation coefficient,cutting force,and minimum cutting thickness.Subsequently,nanocutting experiments were performed using a specially designed nanocutting platform with high-resolution online observation by scanning electron microscopy.The experimental results served to verify the accuracy and reliability of theMDmodeling,as they exhibited excellent consistency with the simulated results.Although this work considered monocrystalline Cu,it is believed that the elucidated chip deformation mechanisms could also be applied to other face-centered-cubic metals.These results are of great value for advancing the understanding of the mechanisms of ultraprecision cutting.
基金supported by the Project Program of Tianjin Key Laboratory of Food Quality and Health,China(No.TJS202302)the National Natural Science Foundation of China(No.31801602)+1 种基金the Fundamental Research Program of Shanxi Province(No.202203021211279)the Natural Science Foundation of Zhejiang Province(LTGN24C150004).
文摘Inducing fruit resistance helps control postharvest diseases effectively.The early signal response plays a crucial role in the subsequent series of fruit resistance reactions.Pichia kudriavzevii was identified as the effective biological elictior for enhancing induced resistance of cherry tomato fruit in this study and the early response signal and its regulatory mechanism subsequently was investigated by RNA sequencing analysis and reverse transcription quantitative real-time PCR(RT-qPCR).Profile trend analysis revealed that,in the early stages of induction(0.5 h and 1 h),the genes related to fruit Ca^(2+)signalling(CML1,CDPK4,CIPK1,and GLR2.9),MAPK signalling(MPK9),the ethylene signalling pathway(ETR2 and EFR1B),and the phenylpropane biosynthesis pathway(PAL5 and 4CL6)respond first.Moreover,the transcription of glutathione pathway genes(GSTU7 and HSP26-A)was upregulated to maintain the balance of reactive oxygen species(ROS)in fruits.After 24 h of induction by P.kudriavzevii,secondary metabolites such as lignin and terpenes in the phenylpropanoid biosynthesis pathway(4CL2,4CL6,CCOAOMT,HMG2,and FPS1),as well as salicylic acid(SA),jasmonic acid(JA),and brassinosteroid(BR)signalling pathways in the plant hormone signalling pathway(TGA1A,TGA9,GH3.5,BAK1,CURL1),were activated.Additionally,upstream genes(PAL5 and 4CL6)in the phenylpropanoid pathway directly activate downstream gene transcription,promoting the production of resistance-related metabolites.P.kudriavzevii induces the activation of early signals such as Ca^(2+) signalling,MAPK signalling,and ethylene signalling,which in turn promote the activation of secondary metabolism and JA,BR,and SA hormone signalling in fruits to regulate resistance responses in fruits.
