Ascorbic acid(AsA),an important antioxidant and growth regulator,and it is essential for plant development and human health.Specifically,humans have to acquire AsA from dietary sources due to their inability to synthe...Ascorbic acid(AsA),an important antioxidant and growth regulator,and it is essential for plant development and human health.Specifically,humans have to acquire AsA from dietary sources due to their inability to synthesize it.The AsA biosynthesis pathway in plants has been elucidated,but its regulatory mechanism remains largely unknown.In this report,we biochemically identified a CCAAT-box transcription factor(SlNFYA10)that can bind to the promoter of SlGME1,which encodes GDP-Man-3’,5’-epimerase,a pivotal enzyme in the D-mannose/L-galactose pathway.Importantly,SlNFYA10 simultaneously binds to the promoter of SlGGP1,a downstream gene of SlGME1 in the Dmannose/L-galactose pathway.Binding assays in yeast and functional analyses in plants have confirmed that SlNFYA10 exerts a negative effect on the expression of both SlGME1 and SlGGP1.Transgenic tomato lines overexpressing SlNFYA10 show decreased levels of SlGME1 and SlGGP1 abundance and AsA concentration in their leaves and fruits,accompanied by enhanced sensitivity to oxidative stress.Overall,SlNFYA10 is the first CCAAT-binding factor identified to date to negatively regulate the AsA biosynthetic pathway at multiple sites and modulate plant responses to oxidative stress.展开更多
1.Introduction In the era of the new century,driven by the development of the intelligent society,the integration of the field of electronics and information with various technical fields and industries has accelerate...1.Introduction In the era of the new century,driven by the development of the intelligent society,the integration of the field of electronics and information with various technical fields and industries has accelerated and become the major driving force for a new round of technological revolution and industrial transformation.This has advanced the profound adjustment of global technology,industry,and division of labor as well as reshaping the innovation and competitiveness of countries around the world.Electronics information has received the most concentrated research and development investment worldwide and has been actively advancing and playing a leading role in dissemination.Naturally,it has become an important strategic area in which the world’s scientific and technological powers seek economic advances and competitive advantages.展开更多
In plants,chloroplasts are the sites at which photosynthesis occurs,and an increased abundance of chloroplasts increases the nutritional quality of plants and the resultant color of fruits.However,the molecular mechan...In plants,chloroplasts are the sites at which photosynthesis occurs,and an increased abundance of chloroplasts increases the nutritional quality of plants and the resultant color of fruits.However,the molecular mechanisms underlying chlorophyll synthesis and chloroplast development in tomato fruits remain unknown.In this study,we isolated a chlorophyll-de fi cient mutant,reduced chlorophyll mutant 1(rcml),by ethylmethanesulfonate mutagenesis;this mutant produced yellowish fruits with altered chloroplast development.MutMap revealed that Solyc08g005010 is the causal gene underlying the rcm1 mutant phenotype.A single-nucleotide base substitution in the second exon of SIRCM1 results in premature termination of its translated protein.SIRCM1 encodes a chloroplast-targeted metalloendopeptidase that is orthologous to the BCM1 protein of Arabidopsis and the stay-green G protein of soybean(Glycine max L.Merr.).Notably,the yellowish phenotype of the lutescent1 mutant can be restored with the allele of SlRCM1 from wild-type tomato.In contrast,knockout of SlRCM1 by the CRISPR/Cas9 system in Alisa Craig yielded yellowish fruits at the mature green stage,as was the case for lutescent1.Amino acid sequence alignment and functional complementation assays showed that SlRCM1 is indeed Lutescent1.These fi ndings provide new insights into the regulation of chloroplast development in tomato fruits.展开更多
Purpose:To investigate the genotyping of Foxp3-3279(A /C,rs376158) genes in patients with dust mite-induced allergic conjunctivitis from Guangdong province and to explore the association between these genes and the su...Purpose:To investigate the genotyping of Foxp3-3279(A /C,rs376158) genes in patients with dust mite-induced allergic conjunctivitis from Guangdong province and to explore the association between these genes and the susceptibility to dust mite allergic conjunctivitis.Methods:.In total,.80 patients with dust mite allergic conjunctivitis and 103 healthy Han Chinese were enrolled in the study and received genotyping of Foxp3-3279(A / C,rs376158)by PCR-SSP technique.Results: Genotype frequency of Foxp3-3279 AA,.CA,.and CC in patients with dust mite allergic conjunctivitis were 1.25%,25.00% and 73.75%,respectively. Gene frequency of C and A in patients with dust mite allergic conjunctivitis were 86.25%and 13.75% with no significant difference from healthy counterparts(both P>0.05).Conclusion:.Foxp3-3279 polymorphisms did not significantly differ between patients with dust mite allergic conjunctivitis and healthy controls, implying that this genetic locus is probably not an independent risk factor of the underlying pathogenesis of dust mite allergic conjunctivitis.展开更多
To predict aeroheating performance of hypersonic vehicles accurately in thermochemical nonequilibrium flows accompanied by rarefaction effect,a Nonlinear Coupled Constitutive Relations(NCCR)model coupled with Gupta’s...To predict aeroheating performance of hypersonic vehicles accurately in thermochemical nonequilibrium flows accompanied by rarefaction effect,a Nonlinear Coupled Constitutive Relations(NCCR)model coupled with Gupta’s chemical models and Park’s two-temperature model is firstly proposed in this paper.Three typical cases are intensively investigated for further validation,including hypersonic flows over a two-dimensional cylinder,a RAM-C II flight vehicle and a type HTV-2 flight vehicle.The results predicted by NCCR solution,such as heat flux coefficient and electron number densities,are in better agreement with those of direct simulation Monte Carlo or flight data than Navier-Stokes equations,especially in the extremely nonequilibrium regions,which indicates the potential of the newly-developed solution to capture both thermochemical and rarefied nonequilibrium effects.The comparisons between the present solver and NCCR model without a two-temperature model are also conducted to demonstrate the significance of vibrational energy source term in the accurate simulation of high-Mach flows.展开更多
The velocity slip and temperature jump for a two-dimensional rough plate under hypersonic conditions were analyzed using the Direct Simulation Monte Carlo(DSMC)method.Surface roughness was explicitly modeled by introd...The velocity slip and temperature jump for a two-dimensional rough plate under hypersonic conditions were analyzed using the Direct Simulation Monte Carlo(DSMC)method.Surface roughness was explicitly modeled by introducing various structures on the flat plate.The influences of relative roughness height,which involves the roughness height,roughness spacing,incoming velocity,and the degree of rarefaction,were analyzed and discussed.It is found that with the increase of the relative roughness height,the jump temperature increases,while the slip velocity decreases gradually.The effects of surface roughness on the slip coefficients can be attributed to the change of accommodation coefficients.A new slip model for rough surfaces was established in this paper,which accounts for the coupling effects of gas rarefaction and surface roughness,without the effort to model the surface roughness explicitly.The nitrogen flows in the microchannel,and flows over a blunt cone and an axisymmetric bi-conic body,were simulated under the modified and conventional slip boundary conditions,respectively.The numerical solutions were validated with experimental data.It can be safely concluded that compared with the traditional first-order slip boundary conditions,the modified slip model improves the accuracy of macroscopic properties,especially the heat transfer coefficient.展开更多
With the consideration of rotation between canopy and payload of parafoil system, a four-degree-of-freedom(4-DOF) longitudinal static model was used to solve parafoil state variables in straight steady flight. The a...With the consideration of rotation between canopy and payload of parafoil system, a four-degree-of-freedom(4-DOF) longitudinal static model was used to solve parafoil state variables in straight steady flight. The aerodynamic solution of parafoil system was a combination of vortex lattice method(VLM) and engineering estimation method. Based on small disturbance assumption,a 6-DOF linear model that considers canopy additional mass was established with benchmark state calculated by 4-DOF static model. Modal analysis of a dynamic model was used to calculate the stability parameters. This method, which is based on a small disturbance linear model and modal analysis, is high-efficiency to the study of parafoil stability. It is well suited for rapid stability analysis in the preliminary stage of parafoil design. Using this method, this paper shows that longitudinal and lateral stability will both decrease when a steady climbing angle increases. This explains the wavy track of the parafoil observed during climbing.展开更多
It is well known that Navier-Stokes equations are not valid for those high-Knudsen and high-Mach flows, in which the local thermodynamically non-equilibrium effects are dominant. To extend the non-equilibrium describi...It is well known that Navier-Stokes equations are not valid for those high-Knudsen and high-Mach flows, in which the local thermodynamically non-equilibrium effects are dominant. To extend the non-equilibrium describing the ability of macroscopic equations, Nonlinear Coupled Constitutive Relation(NCCR) model was developed from Eu’s generalized hydrodynamic equations to substitute linear Newton’s law of viscosity and Fourier’s law of heat conduction in conservation laws. In the NCCR model, how to solve the decomposed constitutive equations with reasonable computational cost is a key ingredient of this scheme. In this paper, an analytic method is proposed firstly. Compared to the iterative procedure in the conventional NCCR model, the analytic method not only obtains exact roots of the decomposed constitutive polynomials, but also preserves the nonlinear constitutive relations in the original framework of NCCR methods. Numerical tests to assess the efficiency and accuracy of the proposed method are conducted for argon shock structures, Couette flows, two-dimensional hypersonic flows over a cylinder and threedimensional supersonic flows over a three-dimensional sphere. These superior advantages of the current method are expected to render itself a powerful tool for simulating the hypersonic rarefied flows and microscale flows of high Knudsen number for engineering applications.展开更多
To overcome the defects of traditional rarefied numerical methods such as the Direct Simulation Monte Carlo(DSMC)method and unified Boltzmann equation schemes and extend the covering range of macroscopic equations in ...To overcome the defects of traditional rarefied numerical methods such as the Direct Simulation Monte Carlo(DSMC)method and unified Boltzmann equation schemes and extend the covering range of macroscopic equations in high Knudsen number flows,data-driven nonlinear constitutive relations(DNCR)are proposed first through the machine learning method.Based on the training data from both Navier-Stokes(NS)solver and unified gas kinetic scheme(UGKS)solver,the map between responses of stress tensors and heat flux and feature vectors is established after the training phase.Through the obtained off-line training model,new test cases excluded from training data set could be predicated rapidly and accurately by solving conventional equations with modified stress tensor and heat flux.Finally,conventional one-dimensional shock wave cases and two-dimensional hypersonic flows around a blunt circular cylinder are presented to assess the capability of the developed method through various comparisons between DNCR,NS,UGKS,DSMC and experimental results.The improvement of the predictive capability of the coarsegraining model could make the DNCR method to be an effective tool in the rarefied gas community,especially for hypersonic engineering applications.展开更多
Hobbing is one of the crucial gear manufacturing processes with high precision and high efficiency.In order to improve the accuracy of hobbing and hob relief grinding,more precise grinding wheels are demanded for reli...Hobbing is one of the crucial gear manufacturing processes with high precision and high efficiency.In order to improve the accuracy of hobbing and hob relief grinding,more precise grinding wheels are demanded for relief grinding in the production of gear hobs.In this paper,a new and accurate mathematical method for calculating the axial profile of grinding wheel based on the corresponding gear hob to be ground is proposed.Considering that most researches have been conducted to focus on the optimization of hob geometric feature and only can be applied to a specific type of hand of helix and rake angle of gear hobs.The method in this paper can be served as a general algorithm for generating axial profile of grinding wheels on the basis of the spatial envelope theory,the principle of coordinate system transformation,and studies on normal profile of single-tooth.The accuracy of grinding hobs is based on applying the approach in practical manufacturing.Taking two typical different kinds of pre-grinding gear hobs as examples for calculation and experiment,the results of tooth profile errors strengthen the position that the validity and feasibility of this method,it can be employed for gear hob design and grinding processing.展开更多
基金supported by grants from the National Key Research&Development Plan(2018YFD1000800,2016YFD0100204-21)National Natural Science Foundation of China(31991182,31972426,and 31672166)+1 种基金Fundamental Research Funds for the Central Universities(2662018PY073)Wuhan Frontier Projects for Applied Foundation(2019020701011492).
文摘Ascorbic acid(AsA),an important antioxidant and growth regulator,and it is essential for plant development and human health.Specifically,humans have to acquire AsA from dietary sources due to their inability to synthesize it.The AsA biosynthesis pathway in plants has been elucidated,but its regulatory mechanism remains largely unknown.In this report,we biochemically identified a CCAAT-box transcription factor(SlNFYA10)that can bind to the promoter of SlGME1,which encodes GDP-Man-3’,5’-epimerase,a pivotal enzyme in the D-mannose/L-galactose pathway.Importantly,SlNFYA10 simultaneously binds to the promoter of SlGGP1,a downstream gene of SlGME1 in the Dmannose/L-galactose pathway.Binding assays in yeast and functional analyses in plants have confirmed that SlNFYA10 exerts a negative effect on the expression of both SlGME1 and SlGGP1.Transgenic tomato lines overexpressing SlNFYA10 show decreased levels of SlGME1 and SlGGP1 abundance and AsA concentration in their leaves and fruits,accompanied by enhanced sensitivity to oxidative stress.Overall,SlNFYA10 is the first CCAAT-binding factor identified to date to negatively regulate the AsA biosynthetic pathway at multiple sites and modulate plant responses to oxidative stress.
基金This work has been supported by the Strategic Research on Disruptive Technologies for Engineering Science and Technology(2019-ZD-27-04).
文摘1.Introduction In the era of the new century,driven by the development of the intelligent society,the integration of the field of electronics and information with various technical fields and industries has accelerated and become the major driving force for a new round of technological revolution and industrial transformation.This has advanced the profound adjustment of global technology,industry,and division of labor as well as reshaping the innovation and competitiveness of countries around the world.Electronics information has received the most concentrated research and development investment worldwide and has been actively advancing and playing a leading role in dissemination.Naturally,it has become an important strategic area in which the world’s scientific and technological powers seek economic advances and competitive advantages.
基金supported by grants from the National Key Research and Development Program of China(2018YFD1000800)the National Natural Science Foundation of China(31991182+3 种基金31972426)the Wuhan Frontier Pr ojects for Applied Fou ndati on(2019020701011492)the Fun dame ntal Research Funds for the Central Universities(2662018PY073)the Hubei Provincial Natural Science Foundation of China(2019CFA017).
文摘In plants,chloroplasts are the sites at which photosynthesis occurs,and an increased abundance of chloroplasts increases the nutritional quality of plants and the resultant color of fruits.However,the molecular mechanisms underlying chlorophyll synthesis and chloroplast development in tomato fruits remain unknown.In this study,we isolated a chlorophyll-de fi cient mutant,reduced chlorophyll mutant 1(rcml),by ethylmethanesulfonate mutagenesis;this mutant produced yellowish fruits with altered chloroplast development.MutMap revealed that Solyc08g005010 is the causal gene underlying the rcm1 mutant phenotype.A single-nucleotide base substitution in the second exon of SIRCM1 results in premature termination of its translated protein.SIRCM1 encodes a chloroplast-targeted metalloendopeptidase that is orthologous to the BCM1 protein of Arabidopsis and the stay-green G protein of soybean(Glycine max L.Merr.).Notably,the yellowish phenotype of the lutescent1 mutant can be restored with the allele of SlRCM1 from wild-type tomato.In contrast,knockout of SlRCM1 by the CRISPR/Cas9 system in Alisa Craig yielded yellowish fruits at the mature green stage,as was the case for lutescent1.Amino acid sequence alignment and functional complementation assays showed that SlRCM1 is indeed Lutescent1.These fi ndings provide new insights into the regulation of chloroplast development in tomato fruits.
基金Science and Technology Planning Project of Guangdong Province,China(2010B031600139)
文摘Purpose:To investigate the genotyping of Foxp3-3279(A /C,rs376158) genes in patients with dust mite-induced allergic conjunctivitis from Guangdong province and to explore the association between these genes and the susceptibility to dust mite allergic conjunctivitis.Methods:.In total,.80 patients with dust mite allergic conjunctivitis and 103 healthy Han Chinese were enrolled in the study and received genotyping of Foxp3-3279(A / C,rs376158)by PCR-SSP technique.Results: Genotype frequency of Foxp3-3279 AA,.CA,.and CC in patients with dust mite allergic conjunctivitis were 1.25%,25.00% and 73.75%,respectively. Gene frequency of C and A in patients with dust mite allergic conjunctivitis were 86.25%and 13.75% with no significant difference from healthy counterparts(both P>0.05).Conclusion:.Foxp3-3279 polymorphisms did not significantly differ between patients with dust mite allergic conjunctivitis and healthy controls, implying that this genetic locus is probably not an independent risk factor of the underlying pathogenesis of dust mite allergic conjunctivitis.
基金financially co-supported by the National Natural Science Foundation of China(Nos.12002306,U20B2007,11572284 and 6162790014)National Numerical Wind Tunnel Project,China(No.NNW2019ZT3-A08)。
文摘To predict aeroheating performance of hypersonic vehicles accurately in thermochemical nonequilibrium flows accompanied by rarefaction effect,a Nonlinear Coupled Constitutive Relations(NCCR)model coupled with Gupta’s chemical models and Park’s two-temperature model is firstly proposed in this paper.Three typical cases are intensively investigated for further validation,including hypersonic flows over a two-dimensional cylinder,a RAM-C II flight vehicle and a type HTV-2 flight vehicle.The results predicted by NCCR solution,such as heat flux coefficient and electron number densities,are in better agreement with those of direct simulation Monte Carlo or flight data than Navier-Stokes equations,especially in the extremely nonequilibrium regions,which indicates the potential of the newly-developed solution to capture both thermochemical and rarefied nonequilibrium effects.The comparisons between the present solver and NCCR model without a two-temperature model are also conducted to demonstrate the significance of vibrational energy source term in the accurate simulation of high-Mach flows.
基金supported by the National Natural Science Foundation of China(Nos.12002306,U20B2007).
文摘The velocity slip and temperature jump for a two-dimensional rough plate under hypersonic conditions were analyzed using the Direct Simulation Monte Carlo(DSMC)method.Surface roughness was explicitly modeled by introducing various structures on the flat plate.The influences of relative roughness height,which involves the roughness height,roughness spacing,incoming velocity,and the degree of rarefaction,were analyzed and discussed.It is found that with the increase of the relative roughness height,the jump temperature increases,while the slip velocity decreases gradually.The effects of surface roughness on the slip coefficients can be attributed to the change of accommodation coefficients.A new slip model for rough surfaces was established in this paper,which accounts for the coupling effects of gas rarefaction and surface roughness,without the effort to model the surface roughness explicitly.The nitrogen flows in the microchannel,and flows over a blunt cone and an axisymmetric bi-conic body,were simulated under the modified and conventional slip boundary conditions,respectively.The numerical solutions were validated with experimental data.It can be safely concluded that compared with the traditional first-order slip boundary conditions,the modified slip model improves the accuracy of macroscopic properties,especially the heat transfer coefficient.
文摘With the consideration of rotation between canopy and payload of parafoil system, a four-degree-of-freedom(4-DOF) longitudinal static model was used to solve parafoil state variables in straight steady flight. The aerodynamic solution of parafoil system was a combination of vortex lattice method(VLM) and engineering estimation method. Based on small disturbance assumption,a 6-DOF linear model that considers canopy additional mass was established with benchmark state calculated by 4-DOF static model. Modal analysis of a dynamic model was used to calculate the stability parameters. This method, which is based on a small disturbance linear model and modal analysis, is high-efficiency to the study of parafoil stability. It is well suited for rapid stability analysis in the preliminary stage of parafoil design. Using this method, this paper shows that longitudinal and lateral stability will both decrease when a steady climbing angle increases. This explains the wavy track of the parafoil observed during climbing.
基金financially supported by the National Natural Science Foundation of China (Nos.:11502232, 51575487,11572284, and 6162790014)support by the China Scholarship Council (No.201906320279)partially performed on resources of the National Supercomputing Centre,Singapore (https://www.nscc.sg)。
文摘It is well known that Navier-Stokes equations are not valid for those high-Knudsen and high-Mach flows, in which the local thermodynamically non-equilibrium effects are dominant. To extend the non-equilibrium describing the ability of macroscopic equations, Nonlinear Coupled Constitutive Relation(NCCR) model was developed from Eu’s generalized hydrodynamic equations to substitute linear Newton’s law of viscosity and Fourier’s law of heat conduction in conservation laws. In the NCCR model, how to solve the decomposed constitutive equations with reasonable computational cost is a key ingredient of this scheme. In this paper, an analytic method is proposed firstly. Compared to the iterative procedure in the conventional NCCR model, the analytic method not only obtains exact roots of the decomposed constitutive polynomials, but also preserves the nonlinear constitutive relations in the original framework of NCCR methods. Numerical tests to assess the efficiency and accuracy of the proposed method are conducted for argon shock structures, Couette flows, two-dimensional hypersonic flows over a cylinder and threedimensional supersonic flows over a three-dimensional sphere. These superior advantages of the current method are expected to render itself a powerful tool for simulating the hypersonic rarefied flows and microscale flows of high Knudsen number for engineering applications.
基金funded by the National Numerical Wind-Tunnel Project(NO.NNW2019ZT3-A08)support of the National Natural Science Foundation of China(Grant No.12002306 and 6162790014).
文摘To overcome the defects of traditional rarefied numerical methods such as the Direct Simulation Monte Carlo(DSMC)method and unified Boltzmann equation schemes and extend the covering range of macroscopic equations in high Knudsen number flows,data-driven nonlinear constitutive relations(DNCR)are proposed first through the machine learning method.Based on the training data from both Navier-Stokes(NS)solver and unified gas kinetic scheme(UGKS)solver,the map between responses of stress tensors and heat flux and feature vectors is established after the training phase.Through the obtained off-line training model,new test cases excluded from training data set could be predicated rapidly and accurately by solving conventional equations with modified stress tensor and heat flux.Finally,conventional one-dimensional shock wave cases and two-dimensional hypersonic flows around a blunt circular cylinder are presented to assess the capability of the developed method through various comparisons between DNCR,NS,UGKS,DSMC and experimental results.The improvement of the predictive capability of the coarsegraining model could make the DNCR method to be an effective tool in the rarefied gas community,especially for hypersonic engineering applications.
基金National Key Research and Development Project of China(2018YFB2001500)。
文摘Hobbing is one of the crucial gear manufacturing processes with high precision and high efficiency.In order to improve the accuracy of hobbing and hob relief grinding,more precise grinding wheels are demanded for relief grinding in the production of gear hobs.In this paper,a new and accurate mathematical method for calculating the axial profile of grinding wheel based on the corresponding gear hob to be ground is proposed.Considering that most researches have been conducted to focus on the optimization of hob geometric feature and only can be applied to a specific type of hand of helix and rake angle of gear hobs.The method in this paper can be served as a general algorithm for generating axial profile of grinding wheels on the basis of the spatial envelope theory,the principle of coordinate system transformation,and studies on normal profile of single-tooth.The accuracy of grinding hobs is based on applying the approach in practical manufacturing.Taking two typical different kinds of pre-grinding gear hobs as examples for calculation and experiment,the results of tooth profile errors strengthen the position that the validity and feasibility of this method,it can be employed for gear hob design and grinding processing.