THE mechanical response and deformation mechanisms of pure nickel under nanoindentation were systematically investigated using molecular dynamics(MD)simulations,with a particular focus on the novel interplay between c...THE mechanical response and deformation mechanisms of pure nickel under nanoindentation were systematically investigated using molecular dynamics(MD)simulations,with a particular focus on the novel interplay between crystallographic orientation,grain boundary(GB)proximity,and pore characteristics(size/location).This study compares single-crystal nickel models along[100],[110],and[111]orientations with equiaxed polycrystalline models containing 0,1,and 2.5 nm pores in surface and subsurface configurations.Our results reveal that crystallographic anisotropy manifests as a 24.4%higher elastic modulus and 22.2%greater hardness in[111]-oriented single crystals compared to[100].Pore-GB synergistic effects are found to dominate the deformation behavior:2.5 nm subsurface pores reduce hardness by 25.2%through stress concentration and dislocation annihilation at GBs,whereas surface pores enable mechanical recovery via accelerated dislocation generation post-collapse.Additionally,size-dependent deformation regimes were identified,with 1 nm pores inducing negligible perturbation due to rapid atomic rearrangement,in contrast with persistent softening in 2.5 nm pores.These findings establish atomic-scale design principles for defect engineering in nickel-based aerospace components,demonstrating how crystallographic orientation,pore configuration,and GB interactions collectively govern nanoindentation behavior.展开更多
Grain filling is a critical determinant of yield and quality in rice.This study aims to clarify the association between grain photosynthesis and the filling rate of rice varieties with different grain weights,providin...Grain filling is a critical determinant of yield and quality in rice.This study aims to clarify the association between grain photosynthesis and the filling rate of rice varieties with different grain weights,providing a theoretical foundation for optimizing grain-filling processes.Two rice varieties with similar growth duration but different grain weights were selected:a large-grain variety,Lingliangyou 268(L268),and a small-grain variety,Ruiliangyou 1053(R1053).Differences in grain filling,grain photosynthetic rate,and grain chlorophyll content were systematically examined during the filling stage.Results showed significant differences in grain-filling,grain photosynthetic rate,and grain chlorophyll content between large-grain and small-grain rice varieties.The grain photosynthetic rate of L268 was a significantly higher than R1053.L268 also exhibited significantly higher initial grain filling rate,maximum grainfilling rate,and mean grain filling rate compared to R1053.Throughout the grain filling period,L268 showed higher grain chlorophyll content(including chlorophyll a,chlorophyll b,and total chlorophyll)than R1053.The increase in chlorophyll content,particularly total chlorophyll,enhanced the grain photosynthetic rate during the early and middle stages of grain filling significantly.These findings suggested that rice varieties with higher grain weights exhibited stronger panicle photosynthetic capacity due to their higher chlorophyll content.The enhanced grain photosynthetic rate contributed to improved grain filling and increased grain weight.展开更多
The liquid metal embrittlement(LME)of advanced high-strength steels caused by zinc(Zn)has become a critical issue hindering their widespread application in the automotive industry.In this study,atomic-scale simulation...The liquid metal embrittlement(LME)of advanced high-strength steels caused by zinc(Zn)has become a critical issue hindering their widespread application in the automotive industry.In this study,atomic-scale simulations are carried out to elucidate the underlying cause of this phenomenon,namely grain boundary embrittlement due to Zn segregation at iron(Fe)grain boundaries.A machine learning moment tensor interatomic potential for the Fe-Zn binary system is developed,based on which the thermodynamics of grain boundary segregation is evaluated.The yielded segregation energy spectrum of Zn in BCC Fe reveals the quantitative relationship between the average segregation concentration of Zn at Fe grain boundaries and the macroscopic Zn content,temperature,and fraction of grain boundary atoms.It suggests a strong thermodynamic driving force for Zn segregation at the Fe grain boundaries,which correlates directly with the grain boundary energy:high-energy grain boundaries can accommodate a large amount of Zn atoms,while low-energy grain boundaries exhibit a certain degree of repulsion to Zn.Kinetically,Zn enters the grain boundaries more easily through diffusion than by penetration.Nonetheless,the grain boundary embrittlement caused by Zn penetration is more severe than that by Zn diffusion.The embrittlement effect generally increases linearly with the increase in Zn concentration at the grain boundary.Altogether,it suggests that the LME in steels induced by grain boundary segregation of Zn emerges as a combined consequence of Zn melt penetration and solid-state diffusion of Zn atoms.展开更多
Reducing water consumption in rice production in China without affecting grain yield and quality is a significant challenge.This study explored how various dry cultivation methods could improve rice quality while bala...Reducing water consumption in rice production in China without affecting grain yield and quality is a significant challenge.This study explored how various dry cultivation methods could improve rice quality while balancing yield to maintain sustainable rice production.A japonica upland rice cultivar and a japonica paddy rice cultivar were cultivated in the field with three cultivation methods:plastic film mulching dry cultivation(PFMC),bare dry cultivation(BC),and continuous flooding cultivation(CF)as control.There was no significant difference in upland rice yield between PFMC and BC,nor in paddy rice yield between PFMC and CF.Compared with CF,the two varieties'yields decreased significantly with BC.Dry cultivation,especially PFMC,could decrease the active filling period,chalky rice rate,chalkiness,amylose content,gel consistency,breakdown viscosity,the ratio of glutelin to prolamin,and leaf senescence while increasing water use efficiency,protein components content,setback viscosity,grain starch branching enzyme(Q-enzyme)activity,and average filling rate.Compared with paddy rice,upland rice had a lower yield,shorter active filling period,lower chalkiness grain rate and gel consistency,higher amylose content,breakdown viscosity,protein components content,and average filling rate.Grain Q-enzyme activity and grain-filling parameters were closely related to rice quality.Reasonable dry cultivation methods could balance yield and quality,especially by improving rice's nutritional and appearance quality.展开更多
Understanding the fracture behavior of rocks subjected to temperature and accounting for the rock's texture is vital for safe and efficient design.Prior studies have often focused on isolated aspects of rock fract...Understanding the fracture behavior of rocks subjected to temperature and accounting for the rock's texture is vital for safe and efficient design.Prior studies have often focused on isolated aspects of rock fracture behavior,neglecting the combined influence of grain size and temperature on fracture behavior.This study employs specimens based on the particle flow code-grain based model to scrutinize the influence of temperature and grain size discrepancies on the fracture characteristics of sandstone.In pursuit of this goal,we manufactured ninety-six semi-circular bend specimens with grain sizes spanning from 0.5 mm to 1.5 mm,predicated on the mineral composition of sandstone.Recognizing the significance of intra-granular and inter-granular fractures,the grains were considered deformable and susceptible to breakage.The numerical model was calibrated using the results of uniaxial compressive strength(UCS)and Brazilian tests.We implemented thermo-mechanical coupled analysis to simulate mode Ⅰ,mode Ⅱ,and mixed mode(Ⅰ-Ⅱ)fracture toughness tests and subsequently studied alterations in the fracture behavior of sandstone at temperatures from 25℃ to 700℃.Our findings revealed increased fracture toughness as the temperature escalated from 25℃ to 200℃.However,beyond the threshold of 200℃,we noted a decline in fracture toughness.More specifically,the drop in mode Ⅰ fracture toughness was more pronounced in specimens with finer grains than those with coarser grains.Contrarily,the trend was reversed for mode Ⅱ fracture toughness.In contrast,the reduction of mixed mode(Ⅰ-Ⅱ)fracture toughness seemed almost linear across all grain sizes.Furthermore,we identified a correlation between temperature and grain size and their collective impact on crack propagation patterns.Comparing our results with established theoretical benchmarks,we confirmed that both temperature and grain size variations influence the fracture envelopes of sandstone.展开更多
Grain boundary engineering plays a significant role in the improvement of strength and plasticity of alloys. However, in refractory high-entropy alloys, the susceptibility of grain boundaries to oxygen presents a bott...Grain boundary engineering plays a significant role in the improvement of strength and plasticity of alloys. However, in refractory high-entropy alloys, the susceptibility of grain boundaries to oxygen presents a bottleneck in achieving high mechanical performance. Creating a large number of clean grain boundaries in refractory high-entropy alloys is a challenge. In this study, an ultrafine-grained (UFG) NbMoTaW alloy with high grain-boundary cohesion was prepared by powder metallurgy, taking advantages of rapid hot-pressing sintering and full-process inert atmosphere protection from powder synthesis to sintering. By oxygen control and an increase in the proportion of grain boundaries, the segregation of oxygen and formation of oxides at grain boundaries were strongly mitigated, thus the intrinsic high cohesion of the interfaces was preserved. Compared to the coarse-grained alloys prepared by arc-melting and those sintered by traditional powder metallurgy methods, the UFG NbMoTaW alloy demonstrated simultaneously increased strength and plasticity at ambient temperature. The highly cohesive grain boundaries not only reduce brittle fractures effectively but also promote intragranular deformation. Consequently, the UFG NbMoTaW alloy achieved a high yield strength even at elevated temperatures, with a remarkable performance of 1117 MPa at 1200 ℃. This work provides a feasible solution for producing refractory high-entropy alloys with low impurity content, refined microstructure, and excellent mechanical performance.展开更多
Three types of NdFeB magnets with the same composition and different grain sizes were prepared,and then the grain boundary diffusion was conducted using metal Tb under the same technical parameters.The effect of grain...Three types of NdFeB magnets with the same composition and different grain sizes were prepared,and then the grain boundary diffusion was conducted using metal Tb under the same technical parameters.The effect of grain size on the grain boundary diffusion process and properties of sintered NdFeB magnets was investigated.The diffusion process was assessed using X-ray diffractometer,field emission scanning electron microscope,and electron probe microanalyzer.The magnetic properties of the magnet before and after diffusion were investigated.The results show that the grain refinement of the magnet leads to higher Tb utilization efficiency and results in higher coercivity at different temperatures.It can be attributed to the formation of a deeper and more complete core-shell structure,resulting in better magnetic isolation and higher anisotropy of the Nd_(2)Fe_(14)B grains.This work may shed light on developing high coercivity with low heavy rare earth elements through grain refinement.展开更多
Inferior grains exhibit delayed developmental processes and reduced metabolic activities compared to superior grains,leading to unstable rice yield and quality.While significant advancements have been achieved in eluc...Inferior grains exhibit delayed developmental processes and reduced metabolic activities compared to superior grains,leading to unstable rice yield and quality.While significant advancements have been achieved in elucidating the physiology of endosperm filling in inferior grains,the role of the embryo remains underexplored and warrants comprehensive investigation.Two Wuyujing 3 mutants,DW024(relatively synchronous;syn-DW024)and DW179(significantly asynchronous;asyn-DW179),with different grain-filling patterns were used in this study.Samples of superior and inferior grains were collected at intervals from 5 to 60 d after fertilization and subsequently dissected into subsamples of the embryo and endosperm.Histochemical staining,biochemical analysis,and RNA sequencing(RNA-seq)were combined to systematically compare developmental and physiological traits between superior and inferior grains.Combining hierarchical clustering of mRNA datasets revealed three developmental phases of the endosperm and embryo:morphogenesis,endosperm filling/embryo enlargement,and maturation.In both syn-DW024 and asyn-DW179,the duration of the endosperm/embryo morphogenesis phase was identical in superior and inferior grains.The inferior grains of asyn-DW179 exhibited a 10-day prolongation in the endosperm filling phase and a 20-day extension in the embryo enlargement phase compared to the superior grains.The endosperm of inferior grains exhibited higher contents of sugars and free amino acids,along with slower accumulation of storage compounds,which was associated with the down-regulation of genes for starch synthesis and ABA signaling.In addition,transporters for nutrient exchanges between endosperm and embryo were down-regulated,suggesting a potential role of the embryo in adjusting the endosperm filling process.Collectively,our results reveal that the prolonged phases of endosperm filling and embryo enlargement may underlie the impaired development of inferior grains,offering a new perspective for breeding or cultivating rice with uniform grain quality.展开更多
Rice grain size is a primary characteristic essential for artificial domestication and breeding,governed by grain length,width,and thickness.In this study,we cloned Grain Size 10(GS10),a novel gene via mapbased clonin...Rice grain size is a primary characteristic essential for artificial domestication and breeding,governed by grain length,width,and thickness.In this study,we cloned Grain Size 10(GS10),a novel gene via mapbased cloning.Biochemical,molecular,and genetic studies were performed to elucidate the GS10 involved grain size mechanism in rice.Mutant of GS10 lead to reduced grain size due to alterations in cell expansion.Additionally,GS10 is responsible for the formation of notched-belly grains,especially in smaller grain varieties possessing loss-function mutations.Overexpression of GS10 in Nipponbare results in increasing grain length,grain weight and improve the appearance quality of rice.GS10 encodes conserved protein with uncharacterized function.Furthermore,GS10 regulates the grain size by interacting OsBRICK1,a subunit of the WAVE complex that governs actin nucleation and affects the assembly of microfilaments in rice.Together,our study demonstrates that,GS10 positively regulates the grain length and grain weight,which is beneficial for further improvements in yield characteristics.展开更多
Wheat is an important cereal crop used to produce diverse and popular food worldwide because of its high grain yield(GY)and grain protein content(GPC).However,GY and GPC are usually negatively correlated.We previously...Wheat is an important cereal crop used to produce diverse and popular food worldwide because of its high grain yield(GY)and grain protein content(GPC).However,GY and GPC are usually negatively correlated.We previously reported that favorable alleles of the wheat domestication gene Q can synchronously increase GY and GPC,but the underlying mechanisms remain largely unknown.In this study,we investigate the regulatory network involving Q associated with GY and GPC in young grains through DNA affinity purification sequencing and transcriptome sequencing analyses,electrophoretic mobility shift and dualluciferase assays,and transgenic approaches.Three Q-binding motifs,namely TTAAGG,AAACA[A/T]A,and GTAC[T/G]A,are identified.Notably,genes related to photosynthesis or carbon and nitrogen metabolism are enriched and regulated by Q.Moreover,Q is revealed to bind directly to its own gene and the glutamine synthetase gene GSr-4D to increase expression,thereby influencing nitrogen assimilation during the grain filling stage and increasing GPC.Considered together,our findings provide molecular evidence of the positive regulatory effects of Q on wheat GY and GPC.展开更多
Rice grain yield is primarily determined by three key agronomic traits:panicle number,grain number per panicle,and grain weight(GW).However,the inherent tradeoffs among these yield components remain a persistent chall...Rice grain yield is primarily determined by three key agronomic traits:panicle number,grain number per panicle,and grain weight(GW).However,the inherent tradeoffs among these yield components remain a persistent challenge in rice breeding programs.Notably,compared with GW,brown rice weight(BRW)provides a more direct metric associated with actual grain yield potential.In this study,we conducted a two-year replicated genome-wide association study to elucidate the genetic architecture of BRW and identify new loci regulating GW.Among seven consistently detected loci across experimental replicates,four were not co-localized with previously reported genes associated with BRW or GW traits.BRW1.1,one of the four newly identified loci,was found to encode a novel RNA-binding protein.Functional characterization revealed that BRW1.1 acts as a negative regulator of BRW,potentially through modulating mRNA translation processes.Intriguingly,through integrated analysis of mutant phenotypes and haplotype variations,we demonstrated that BRW1.1 mediates the physiological tradeoff between GW and panicle number.This study not only delineates the genetic determinants of BRW but also identifies BRW1.1 as a promising molecular target for breaking the yield component tradeoff in precision rice breeding.展开更多
Late sowing is a critical factor that hinders achieving high-yield,good-quality wheat under rice-wheat rotation.Understanding the physiological basis and regulatory pathways that lead to high yield and sound quality l...Late sowing is a critical factor that hinders achieving high-yield,good-quality wheat under rice-wheat rotation.Understanding the physiological basis and regulatory pathways that lead to high yield and sound quality late-sown wheat is crucial for developing effective cultivation strategies.A 2-year field experiment was conducted to investigate the effects of sowing date,nitrogen(N)application rate,and planting density on wheat yield,grain quality,population characteristics,and the underlying physiological factors.The results revealed significant interactions among the sowing date,planting density,and N application in regulating both yield and quality.Late sowing reduced grain yield primarily by reducing the number of spikes and kernels.However,the latter was improved by increasing N application and the planting density,thus mitigating the yield losses caused by late sowing.Moreover,the grain protein content(GPC)and wet gluten content(WGC)increased with delayed sowing dates and higher N rates but decreased with increased planting densities.For wheat yields over 9,000 or 7,500 kg ha^(-1),the latest sowing date should not be later than Nov.4 or 15,respectively.In addition,specific criteria should be met,including a maximum of 1.5 and 1.0 million stems and tillers ha^(-1),a maximum leaf area index of 6.7 and 5.5,and a dry matter accumulation(DMA)at anthesis of 14,000 and 12,000 kg ha^(-1),respectively.For high-yield,good-quality late-sown wheat,the optimal combination is a 25%increase in the N rate(300 kg N ha^(-1))and a planting density of 2.25 million(N300D225)or 3.75 million(N300D375)plants ha^(-1)for 10-or 20-day delays in sowing,respectively.These combinations result in a higher leaf net photosynthetic rate,higher activities of leaf nitrate reductase,glutamine synthetase,grain glutamic pyruvic transaminase,and a lower sugar-N ratio during post-anthesis.展开更多
Rice grain size and chalkiness are important traits that influence grain yield and quality,respectively.Mining of genes for grain yield and appearance quality and clarification of their action modes are of great impor...Rice grain size and chalkiness are important traits that influence grain yield and quality,respectively.Mining of genes for grain yield and appearance quality and clarification of their action modes are of great importance in rice breeding.In this study,a rice protein disulfide isomerase-like enzyme PDIL2-3 was characterized.Expression analysis revealed that PDIL2-3 was highly expressed in endosperm and spikelet hulls.The PDIL2-3-cri lines generated by CRISPR/Cas9 technology exhibited a chalky grain phenotype with altered storage substance accumulation and increased grain size and weight,whereas exactly opposite results were obtained for PDIL2-3 overexpression lines.Cytological experiments revealed that PDIL2-3-cri increased rice seed length mainly by increasing the cell number and rice seed width mainly by increasing the cell size in grains,implying that PDIL2-3 regulates the grain size by influencing both cell division and expansion of spikelet hulls.Further flow cytometric analysis validated that PDIL2-3 has a negative effect on cell proliferation,preventing DNA duplication and cell division in spikelet hulls.Moreover,q RT-PCR results showed that the expression levels of genes related to cell cycle and storage substance synthesis were significantly changed in PDIL2-3-cri transgenic lines.Thus,our results indicated that PDIL2-3 plays a pivotal role in influencing grain size and quality of rice by affecting cell division/expansion and storage substance accumulation,providing new insights into the function of PDIL family members in rice and enriching the genetic resources for rice breeding.展开更多
Wheat grain morphology,particularly grain length(GL)and width(GW),is a key determinant of yield.To improve the suboptimal grain dimensions of the local anthocyanin-rich variety Guizi 1(GZ1),we crossed it with Zhongyan...Wheat grain morphology,particularly grain length(GL)and width(GW),is a key determinant of yield.To improve the suboptimal grain dimensions of the local anthocyanin-rich variety Guizi 1(GZ1),we crossed it with Zhongyan 96-3(ZY96-3),an elite germplasm known for faster grain filling and superior grain size.A genotyping-by-sequencing(GBS)approach was applied to an F_(2)population of 110 individuals derived from GZ1×ZY96-3,resulting in the identification of 23,134 high-quality SNPs.Most of the SNPs associated with GL and GW were clustered on chromosomes 2B,3A,and 3B.QTL mapping for GL revealed two major loci,GL1 on chromosome 2B and GL2 on chromosome 3B,and eight candidate genes were identified within their corresponding intervals(2B:63.6–70.4 Mb;3B:631.5–633.3 Mb).These genes encode proteins potentially involved in grain size regulation,including a TOR2 regulation-associated protein,erect spike 2(EP2),fibroblast growth factor 6(FGF6),cellulose synthase-like(CSLD),RelA/pot homologue three family protein,and three GDSL esterase/lipase(GLIP)proteins.Additionally,we detected a QTL associated with GW on chromosome 3A and identified two candidate genes,TOR2 regulation and starch synthase within the 61.4–68.5 Mb interval.Overall,this study provides a strong theoretical and technical basis for wheat genetic improvement and offers valuable resources for precise QTL mapping and candidate gene discovery.展开更多
Irrigation methods and nitrogen(N) fertilization modes have complicated impacts on wheat physiology, growth, and development, leading to the regulation of wheat grain yield and quality. However, the optimal water-N co...Irrigation methods and nitrogen(N) fertilization modes have complicated impacts on wheat physiology, growth, and development, leading to the regulation of wheat grain yield and quality. However, the optimal water-N combination for drip-irrigated winter wheat remains unclear. A two-year field study was conducted to evaluate the influences of various N-fertigation and water regimes on wheat post-anthesis grain weight variation, yield, grain NPK content, and grain quality. The two irrigation quotas were I_(45)(irrigation when crop evapotranspiration reduced by effective rainfall(ETa-P) reaches 45 mm) and I_(30)(irrigation when ETa-P reaches 30 mm), while the six N application rates were N_(0–100)(100% at jointing/booting), N_(25–75)(25% at sowing and 75% at jointing/booting), N_(50–50)(50% at sowing and 50% at jointing/booting), N_(75–25)(75% at sowing and 25% at jointing/booting), N_(100–0)(100% at sowing), and SRF100(100% of slow-release fertilizer at sowing). The experimental findings showed that post-anthesis grain weight variation, grain yield, grain NPK content, and grain quality were all markedly influenced by the various irrigation schedules and N-fertilization modes. The N_(50–50)treatment was more beneficial for winter wheat post-anthesis grain weight variation than the N_(100–0)and N_(0–100)treatments under the two irrigation quotas and during the two seasons. The highest grain yields of 9.72 and9.94(t ha^(-1)) were obtained with the I_(45)N_(50–50)treatment in 2020–2021 and 2021–2022, respectively. The grain crudeprotein was higher in the I_(45)SRF100treatment during the two seasons. The I_(45)N_(100–0)combination significantly(P<0.05)enhanced the content of grain total starch by 7.30 and 8.23% compared with the I_(45)N_(0–100)and I_(30)N_(0–100)treatments,respectively, during the 2021–2021 season. The I_(45)N_(100–0)treatment significantly(P<0.05) enhanced the content ofgrain total starch concentration by 7.77, 7.62 and 7.88% compared with the I_(45)N_(0–100), I_(30)N_(0–100), and I_(30)N_(25–75)treatments,respectively, in the 2021–2022 season. The principal component analysis(PCA) indicated that the N_(50–50)splitN-fertigation mode could be the optimal choice for farmers during winter wheat production via drip irrigation.展开更多
Although 316L stainless steel(SS316L)exhibits favorable ductility and toughness,its limited strength restricts its applicability.This study addressed this limitation by preparing a series of SS316L-xTC4 alloys(where x...Although 316L stainless steel(SS316L)exhibits favorable ductility and toughness,its limited strength restricts its applicability.This study addressed this limitation by preparing a series of SS316L-xTC4 alloys(where x indicates Ti6Al4V(TC4)contents of 0.5 wt%,1 wt%,2 wt%,and 4 wt%)with equiaxed grains,ultrafine grains,and heterogeneous structures using in-situ alloying via laser powder bed fusion.The Ti,Al,and V in the TC4 alloy were shown to stabilize and promote the formation of theαphase,which is stronger than theγphase in typical SS316L.Furthermore,these solute elements readily formed nanoparticles with impurities,such as C and O,to increase the nucleation rate and thereby achieve grain refinement.This resulted in the formation of ultrafine grains predominantly within theαphase,where the solute elements were primarily distributed.The formation of theαphase also impeded the growth of theγphase;coupled with the effects of the nanoparticles,this also significantly reduced the grain size in theγphase.Notably,the SS316L-2TC4 alloy exhibited fully equiaxed grains,and the coexistence of theαandγphases as well as ultrafine and coarse grains formed heterogeneous grain and dual-phase structures within.The synergistic effects of equiaxed grains,ultrafine grains,and heterostructures produced an SS316L alloy that exhibited both excellent strength and elongation.展开更多
Grain size and formation of the Peripheral Coarse Grain(PCG)defect influence the mechanical and crash properties of extruded profiles.Controlling microstructural evolution during the extrusion of 6XXX series aluminum ...Grain size and formation of the Peripheral Coarse Grain(PCG)defect influence the mechanical and crash properties of extruded profiles.Controlling microstructural evolution during the extrusion of 6XXX series aluminum alloys is therefore essential to ensure the performance of structural components.In this work,three profiles with the same nominal geometry were extruded with a die comprising three different bearing geometries to create different extrusion conditions.Each profile was analyzed experimentally to gather data on the microstructure and mechanical properties.Bulge testing revealed that Profile 2,with the thickest PCG layer(490-1150µm),exhibited worse mechanical performance,with a hoop strain at fracture of 0.08 and a peak load of 51.5 kN,compared to Profiles 1 and 3,which had higher hoop strains(0.13 and 0.14)and peak loads(56.1 and 57.6 kN,respectively).Finite Element Method(FEM)simulations of the extrusion process were carried out using Qform Extrusion UK with a post-processing subroutine developed and implemented to calculate additional parameters such as the stored energy,percentage dynamic recrystallization,grain size,and PCG formation based on standard output parameters from the simulation including strain,temperature and strain rate.The simulation demonstrated that the highest strain rate(40-220 s^(-1))and stored energy(150,000-440,000 J m^(-3))in Profile 2 led to the thickest PCG layer.Based on these results,the proposed predictive model was validated against experimental data,demonstrating high accuracy in predicting PCG thickness and grain size while effectively capturing the influence of process parameters on microstructural evolution.展开更多
A metallurgical model for austenite coarsening in the coarse-grained heat-affected zone(CGHAZ)containing titanium nitride(TiN)precipitation was studied.Unlike traditional methods estimating pinning capability based on...A metallurgical model for austenite coarsening in the coarse-grained heat-affected zone(CGHAZ)containing titanium nitride(TiN)precipitation was studied.Unlike traditional methods estimating pinning capability based on the precipitation size after welding,a proposed dissolution and coarsening model was applied to study the changes in TiN precipitation size and the associated pinning forces.The transmission electron microscope was used to analyze the size distribution of TiN particles before and after the welding thermal cycle.The size distribution showed a log-normal distribution before the thermal cycle.The prediction of post-thermal cycle size distributions with the proposed model was in agreement with the experimental results.Considering the short holding time at high temperature during welding,the thermodynamic stability conditions required for limiting grain size model cannot be achieved.A simple kinetic model for the prediction of austenite grain size in CGHAZ was established.Finally,the predicted austenite grain sizes agree better with experimental results than the conventional approach.展开更多
The scratching mechanism of polycrystallineγ-TiAl alloy was investigated at the atomic scale using the molecular dynamics method,with a focus on the influence of different grain sizes.The analysis encompassed tribolo...The scratching mechanism of polycrystallineγ-TiAl alloy was investigated at the atomic scale using the molecular dynamics method,with a focus on the influence of different grain sizes.The analysis encompassed tribological characteristics,scratch morphology,subsurface defect distribution,temperature variations,and stress states during the scratching process.The findings indicate that the scratch force,number of recovered atoms,and pile-up height exhibit abrupt changes when the critical size is 9.41 nm due to the influence of the inverse Hall-Petch effect.Variations in the number of grain boundaries and randomness of grain orientation result in different accumulation patterns on the scratch surface.Notably,single crystal materials and those with 3.73 nm in grain size display more regular surface morphology.Furthermore,smaller grain size leads to an increase in average coefficient of friction,removed atoms number,and wear rate.While it also causes higher temperatures with a larger range of distributions.Due to the barrier effect of grain boundaries,smaller grains exhibit reduced microscopic defects.Additionally,average von Mises stress and hydrostatic compressive stress at the indenter tip decrease as grain size decreases owing to grain boundary obstruction.展开更多
As-forged WSTi6421 titanium alloy billet afterβannealing was investigated.Abnormally coarse grains larger than adjacent grains could be observed in the microstructures,forming abnormal grain structures with uneven si...As-forged WSTi6421 titanium alloy billet afterβannealing was investigated.Abnormally coarse grains larger than adjacent grains could be observed in the microstructures,forming abnormal grain structures with uneven size distribution.Through electron backscattered diffraction(EBSD),the forged microstructure at various locations of as-forged WSTi6421 titanium alloy billet was analyzed,revealing that the strength of theβphase cubic texture generated by forging significantly influences the grain size afterβannealing.Heat treatment experiments were conducted within the temperature range from T_(β)−50°C to T_(β)+10°C to observe the macro-and micro-morphologies.Results show that the cubic texture ofβphase caused by forging impacts the texture of the secondaryαphase,which subsequently influences theβphase formed during the post-βannealing process.Moreover,the pinning effect of the residual primaryαphase plays a crucial role in the growth ofβgrains during theβannealing process.EBSD analysis results suggest that the strength ofβphase with cubic texture formed during forging process impacts the orientation distribution differences ofβgrains afterβannealing.Additionally,the development of grains with large orientations within the cubic texture shows a certain degree of selectivity duringβannealing,which is affected by various factors,including the pinning effect of the primaryαphase,the strength of the matrix cubic texture,and the orientation relationship betweenβgrain and matrix.Comprehensively,the stronger the texture in a certain region,the less likely the large misoriented grains suffering secondary growth,thereby aggregating the difference in microstructure and grain orientation distribution across different regions afterβannealing.展开更多
基金The National Natural Science Foundation of China(Grant No.12462006)Beijing Institute of Structure and Environment Engineering Joint Innovation Fund(No.BQJJ202414).
文摘THE mechanical response and deformation mechanisms of pure nickel under nanoindentation were systematically investigated using molecular dynamics(MD)simulations,with a particular focus on the novel interplay between crystallographic orientation,grain boundary(GB)proximity,and pore characteristics(size/location).This study compares single-crystal nickel models along[100],[110],and[111]orientations with equiaxed polycrystalline models containing 0,1,and 2.5 nm pores in surface and subsurface configurations.Our results reveal that crystallographic anisotropy manifests as a 24.4%higher elastic modulus and 22.2%greater hardness in[111]-oriented single crystals compared to[100].Pore-GB synergistic effects are found to dominate the deformation behavior:2.5 nm subsurface pores reduce hardness by 25.2%through stress concentration and dislocation annihilation at GBs,whereas surface pores enable mechanical recovery via accelerated dislocation generation post-collapse.Additionally,size-dependent deformation regimes were identified,with 1 nm pores inducing negligible perturbation due to rapid atomic rearrangement,in contrast with persistent softening in 2.5 nm pores.These findings establish atomic-scale design principles for defect engineering in nickel-based aerospace components,demonstrating how crystallographic orientation,pore configuration,and GB interactions collectively govern nanoindentation behavior.
基金supported by the Hunan Provincial Natural Science Foundation of China(Grant No.2023JJ40309)the Changsha Outstanding Innovative Youth Training Program(kq2306015).
文摘Grain filling is a critical determinant of yield and quality in rice.This study aims to clarify the association between grain photosynthesis and the filling rate of rice varieties with different grain weights,providing a theoretical foundation for optimizing grain-filling processes.Two rice varieties with similar growth duration but different grain weights were selected:a large-grain variety,Lingliangyou 268(L268),and a small-grain variety,Ruiliangyou 1053(R1053).Differences in grain filling,grain photosynthetic rate,and grain chlorophyll content were systematically examined during the filling stage.Results showed significant differences in grain-filling,grain photosynthetic rate,and grain chlorophyll content between large-grain and small-grain rice varieties.The grain photosynthetic rate of L268 was a significantly higher than R1053.L268 also exhibited significantly higher initial grain filling rate,maximum grainfilling rate,and mean grain filling rate compared to R1053.Throughout the grain filling period,L268 showed higher grain chlorophyll content(including chlorophyll a,chlorophyll b,and total chlorophyll)than R1053.The increase in chlorophyll content,particularly total chlorophyll,enhanced the grain photosynthetic rate during the early and middle stages of grain filling significantly.These findings suggested that rice varieties with higher grain weights exhibited stronger panicle photosynthetic capacity due to their higher chlorophyll content.The enhanced grain photosynthetic rate contributed to improved grain filling and increased grain weight.
基金financially supported by the National Natural Science Foundation of China(No.52071204)Natural Science Foundation of Shanghai Municipal(No.22ZR1428700)SJTU Kunpeng&Ascend Center of Excellence,and MaGIC of Shanghai Jiao Tong University.
文摘The liquid metal embrittlement(LME)of advanced high-strength steels caused by zinc(Zn)has become a critical issue hindering their widespread application in the automotive industry.In this study,atomic-scale simulations are carried out to elucidate the underlying cause of this phenomenon,namely grain boundary embrittlement due to Zn segregation at iron(Fe)grain boundaries.A machine learning moment tensor interatomic potential for the Fe-Zn binary system is developed,based on which the thermodynamics of grain boundary segregation is evaluated.The yielded segregation energy spectrum of Zn in BCC Fe reveals the quantitative relationship between the average segregation concentration of Zn at Fe grain boundaries and the macroscopic Zn content,temperature,and fraction of grain boundary atoms.It suggests a strong thermodynamic driving force for Zn segregation at the Fe grain boundaries,which correlates directly with the grain boundary energy:high-energy grain boundaries can accommodate a large amount of Zn atoms,while low-energy grain boundaries exhibit a certain degree of repulsion to Zn.Kinetically,Zn enters the grain boundaries more easily through diffusion than by penetration.Nonetheless,the grain boundary embrittlement caused by Zn penetration is more severe than that by Zn diffusion.The embrittlement effect generally increases linearly with the increase in Zn concentration at the grain boundary.Altogether,it suggests that the LME in steels induced by grain boundary segregation of Zn emerges as a combined consequence of Zn melt penetration and solid-state diffusion of Zn atoms.
基金he National Key Research and Development Program of China(2022YFD2300304)the National Natural Science Foundation of China(31671617)a project funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD),China。
文摘Reducing water consumption in rice production in China without affecting grain yield and quality is a significant challenge.This study explored how various dry cultivation methods could improve rice quality while balancing yield to maintain sustainable rice production.A japonica upland rice cultivar and a japonica paddy rice cultivar were cultivated in the field with three cultivation methods:plastic film mulching dry cultivation(PFMC),bare dry cultivation(BC),and continuous flooding cultivation(CF)as control.There was no significant difference in upland rice yield between PFMC and BC,nor in paddy rice yield between PFMC and CF.Compared with CF,the two varieties'yields decreased significantly with BC.Dry cultivation,especially PFMC,could decrease the active filling period,chalky rice rate,chalkiness,amylose content,gel consistency,breakdown viscosity,the ratio of glutelin to prolamin,and leaf senescence while increasing water use efficiency,protein components content,setback viscosity,grain starch branching enzyme(Q-enzyme)activity,and average filling rate.Compared with paddy rice,upland rice had a lower yield,shorter active filling period,lower chalkiness grain rate and gel consistency,higher amylose content,breakdown viscosity,protein components content,and average filling rate.Grain Q-enzyme activity and grain-filling parameters were closely related to rice quality.Reasonable dry cultivation methods could balance yield and quality,especially by improving rice's nutritional and appearance quality.
文摘Understanding the fracture behavior of rocks subjected to temperature and accounting for the rock's texture is vital for safe and efficient design.Prior studies have often focused on isolated aspects of rock fracture behavior,neglecting the combined influence of grain size and temperature on fracture behavior.This study employs specimens based on the particle flow code-grain based model to scrutinize the influence of temperature and grain size discrepancies on the fracture characteristics of sandstone.In pursuit of this goal,we manufactured ninety-six semi-circular bend specimens with grain sizes spanning from 0.5 mm to 1.5 mm,predicated on the mineral composition of sandstone.Recognizing the significance of intra-granular and inter-granular fractures,the grains were considered deformable and susceptible to breakage.The numerical model was calibrated using the results of uniaxial compressive strength(UCS)and Brazilian tests.We implemented thermo-mechanical coupled analysis to simulate mode Ⅰ,mode Ⅱ,and mixed mode(Ⅰ-Ⅱ)fracture toughness tests and subsequently studied alterations in the fracture behavior of sandstone at temperatures from 25℃ to 700℃.Our findings revealed increased fracture toughness as the temperature escalated from 25℃ to 200℃.However,beyond the threshold of 200℃,we noted a decline in fracture toughness.More specifically,the drop in mode Ⅰ fracture toughness was more pronounced in specimens with finer grains than those with coarser grains.Contrarily,the trend was reversed for mode Ⅱ fracture toughness.In contrast,the reduction of mixed mode(Ⅰ-Ⅱ)fracture toughness seemed almost linear across all grain sizes.Furthermore,we identified a correlation between temperature and grain size and their collective impact on crack propagation patterns.Comparing our results with established theoretical benchmarks,we confirmed that both temperature and grain size variations influence the fracture envelopes of sandstone.
基金supported by the National Natural Science Foundation of China(Nos.52371128,52304378,52101031 and 92163107).
文摘Grain boundary engineering plays a significant role in the improvement of strength and plasticity of alloys. However, in refractory high-entropy alloys, the susceptibility of grain boundaries to oxygen presents a bottleneck in achieving high mechanical performance. Creating a large number of clean grain boundaries in refractory high-entropy alloys is a challenge. In this study, an ultrafine-grained (UFG) NbMoTaW alloy with high grain-boundary cohesion was prepared by powder metallurgy, taking advantages of rapid hot-pressing sintering and full-process inert atmosphere protection from powder synthesis to sintering. By oxygen control and an increase in the proportion of grain boundaries, the segregation of oxygen and formation of oxides at grain boundaries were strongly mitigated, thus the intrinsic high cohesion of the interfaces was preserved. Compared to the coarse-grained alloys prepared by arc-melting and those sintered by traditional powder metallurgy methods, the UFG NbMoTaW alloy demonstrated simultaneously increased strength and plasticity at ambient temperature. The highly cohesive grain boundaries not only reduce brittle fractures effectively but also promote intragranular deformation. Consequently, the UFG NbMoTaW alloy achieved a high yield strength even at elevated temperatures, with a remarkable performance of 1117 MPa at 1200 ℃. This work provides a feasible solution for producing refractory high-entropy alloys with low impurity content, refined microstructure, and excellent mechanical performance.
基金Key Research and Development Program of Shandong Province(2021CXGC010310)Shandong Province Science and Technology Small and Medium Sized Enterprise Innovation Ability Enhancement Project(2023TSGC0287,2024TSGC0519)+1 种基金Shandong Provincial Natural Science Foundation(ZR2022ME222)National Natural Science Foundation of China(51702187)。
文摘Three types of NdFeB magnets with the same composition and different grain sizes were prepared,and then the grain boundary diffusion was conducted using metal Tb under the same technical parameters.The effect of grain size on the grain boundary diffusion process and properties of sintered NdFeB magnets was investigated.The diffusion process was assessed using X-ray diffractometer,field emission scanning electron microscope,and electron probe microanalyzer.The magnetic properties of the magnet before and after diffusion were investigated.The results show that the grain refinement of the magnet leads to higher Tb utilization efficiency and results in higher coercivity at different temperatures.It can be attributed to the formation of a deeper and more complete core-shell structure,resulting in better magnetic isolation and higher anisotropy of the Nd_(2)Fe_(14)B grains.This work may shed light on developing high coercivity with low heavy rare earth elements through grain refinement.
基金supported by the National Key Research and Development Program of China(2022YFD2300700)the National Natural Science Foundation of China(32201894)+1 种基金Hainan Provincial Natural Science Foundation of China(323QN193)Rothamsted Research receives strategic funding from the Biotechnological and Biological Sciences Research Council of the UK.Matthew J.Paul acknowledges funding from the Delivering Sustainable Wheat(BB/X011003/1)Strategic Program.
文摘Inferior grains exhibit delayed developmental processes and reduced metabolic activities compared to superior grains,leading to unstable rice yield and quality.While significant advancements have been achieved in elucidating the physiology of endosperm filling in inferior grains,the role of the embryo remains underexplored and warrants comprehensive investigation.Two Wuyujing 3 mutants,DW024(relatively synchronous;syn-DW024)and DW179(significantly asynchronous;asyn-DW179),with different grain-filling patterns were used in this study.Samples of superior and inferior grains were collected at intervals from 5 to 60 d after fertilization and subsequently dissected into subsamples of the embryo and endosperm.Histochemical staining,biochemical analysis,and RNA sequencing(RNA-seq)were combined to systematically compare developmental and physiological traits between superior and inferior grains.Combining hierarchical clustering of mRNA datasets revealed three developmental phases of the endosperm and embryo:morphogenesis,endosperm filling/embryo enlargement,and maturation.In both syn-DW024 and asyn-DW179,the duration of the endosperm/embryo morphogenesis phase was identical in superior and inferior grains.The inferior grains of asyn-DW179 exhibited a 10-day prolongation in the endosperm filling phase and a 20-day extension in the embryo enlargement phase compared to the superior grains.The endosperm of inferior grains exhibited higher contents of sugars and free amino acids,along with slower accumulation of storage compounds,which was associated with the down-regulation of genes for starch synthesis and ABA signaling.In addition,transporters for nutrient exchanges between endosperm and embryo were down-regulated,suggesting a potential role of the embryo in adjusting the endosperm filling process.Collectively,our results reveal that the prolonged phases of endosperm filling and embryo enlargement may underlie the impaired development of inferior grains,offering a new perspective for breeding or cultivating rice with uniform grain quality.
基金supported by Projects of International Cooperation NSFC(31961143016,31101203)Guizhou Provincial Science and Technology Projects(QKHJC-ZK[2022]YB537)+4 种基金the Fundamental Research Funds of Central Public Welfare Research Institutions(CPSIBRF-CNRRI-202102,Y2020YJ17)Independent Project of State Key Laboratory of Rice Biology(2020Z2KT10201)High-quality and Resistant Hybrid Rice Germplasm Creation and New Varieties Development with International Competitiveness(2022KJCX45,YBXM2437)Zhejiang Provincial Science and Technology Projects(2022R51009)Inner Mongolia Breeding Joint Research Project(YZ2023004).
文摘Rice grain size is a primary characteristic essential for artificial domestication and breeding,governed by grain length,width,and thickness.In this study,we cloned Grain Size 10(GS10),a novel gene via mapbased cloning.Biochemical,molecular,and genetic studies were performed to elucidate the GS10 involved grain size mechanism in rice.Mutant of GS10 lead to reduced grain size due to alterations in cell expansion.Additionally,GS10 is responsible for the formation of notched-belly grains,especially in smaller grain varieties possessing loss-function mutations.Overexpression of GS10 in Nipponbare results in increasing grain length,grain weight and improve the appearance quality of rice.GS10 encodes conserved protein with uncharacterized function.Furthermore,GS10 regulates the grain size by interacting OsBRICK1,a subunit of the WAVE complex that governs actin nucleation and affects the assembly of microfilaments in rice.Together,our study demonstrates that,GS10 positively regulates the grain length and grain weight,which is beneficial for further improvements in yield characteristics.
基金supported by the National Key Research and Development Program of China(2023YFD1200404)the Science and Technology Department of Sichuan Province(2024ZYD0160)the National Natural Science Foundation of China(32072054).
文摘Wheat is an important cereal crop used to produce diverse and popular food worldwide because of its high grain yield(GY)and grain protein content(GPC).However,GY and GPC are usually negatively correlated.We previously reported that favorable alleles of the wheat domestication gene Q can synchronously increase GY and GPC,but the underlying mechanisms remain largely unknown.In this study,we investigate the regulatory network involving Q associated with GY and GPC in young grains through DNA affinity purification sequencing and transcriptome sequencing analyses,electrophoretic mobility shift and dualluciferase assays,and transgenic approaches.Three Q-binding motifs,namely TTAAGG,AAACA[A/T]A,and GTAC[T/G]A,are identified.Notably,genes related to photosynthesis or carbon and nitrogen metabolism are enriched and regulated by Q.Moreover,Q is revealed to bind directly to its own gene and the glutamine synthetase gene GSr-4D to increase expression,thereby influencing nitrogen assimilation during the grain filling stage and increasing GPC.Considered together,our findings provide molecular evidence of the positive regulatory effects of Q on wheat GY and GPC.
基金supported by the National Natural Science Foundation of China(Grant Nos.32000377,32172037,and 32472211)the Biological Breeding-National Science and Technology Major Project,China(Grant No.2023ZD04068)+2 种基金the Fundamental Research Funds for the Central Universities,China(Grant No.KJQN202103)the open funds of the State Key Laboratory of Crop Genetics&Germplasm Enhancement and Utilization,China(Grant No.ZW202401)the Cyrus Tang Innovation Center for Crop Seed Industry,China.
文摘Rice grain yield is primarily determined by three key agronomic traits:panicle number,grain number per panicle,and grain weight(GW).However,the inherent tradeoffs among these yield components remain a persistent challenge in rice breeding programs.Notably,compared with GW,brown rice weight(BRW)provides a more direct metric associated with actual grain yield potential.In this study,we conducted a two-year replicated genome-wide association study to elucidate the genetic architecture of BRW and identify new loci regulating GW.Among seven consistently detected loci across experimental replicates,four were not co-localized with previously reported genes associated with BRW or GW traits.BRW1.1,one of the four newly identified loci,was found to encode a novel RNA-binding protein.Functional characterization revealed that BRW1.1 acts as a negative regulator of BRW,potentially through modulating mRNA translation processes.Intriguingly,through integrated analysis of mutant phenotypes and haplotype variations,we demonstrated that BRW1.1 mediates the physiological tradeoff between GW and panicle number.This study not only delineates the genetic determinants of BRW but also identifies BRW1.1 as a promising molecular target for breaking the yield component tradeoff in precision rice breeding.
基金supported by the National Natural Science Foundation of China(32272215)the Key R&D Program of Jiangsu Province,China(BE2021361-1)the Collaborative Innovation Center for Modern Crop Production by Province and Ministry(CIC-MCP),Nanjing Agricultural University,China。
文摘Late sowing is a critical factor that hinders achieving high-yield,good-quality wheat under rice-wheat rotation.Understanding the physiological basis and regulatory pathways that lead to high yield and sound quality late-sown wheat is crucial for developing effective cultivation strategies.A 2-year field experiment was conducted to investigate the effects of sowing date,nitrogen(N)application rate,and planting density on wheat yield,grain quality,population characteristics,and the underlying physiological factors.The results revealed significant interactions among the sowing date,planting density,and N application in regulating both yield and quality.Late sowing reduced grain yield primarily by reducing the number of spikes and kernels.However,the latter was improved by increasing N application and the planting density,thus mitigating the yield losses caused by late sowing.Moreover,the grain protein content(GPC)and wet gluten content(WGC)increased with delayed sowing dates and higher N rates but decreased with increased planting densities.For wheat yields over 9,000 or 7,500 kg ha^(-1),the latest sowing date should not be later than Nov.4 or 15,respectively.In addition,specific criteria should be met,including a maximum of 1.5 and 1.0 million stems and tillers ha^(-1),a maximum leaf area index of 6.7 and 5.5,and a dry matter accumulation(DMA)at anthesis of 14,000 and 12,000 kg ha^(-1),respectively.For high-yield,good-quality late-sown wheat,the optimal combination is a 25%increase in the N rate(300 kg N ha^(-1))and a planting density of 2.25 million(N300D225)or 3.75 million(N300D375)plants ha^(-1)for 10-or 20-day delays in sowing,respectively.These combinations result in a higher leaf net photosynthetic rate,higher activities of leaf nitrate reductase,glutamine synthetase,grain glutamic pyruvic transaminase,and a lower sugar-N ratio during post-anthesis.
基金supported in part by grants from the National Natural Science Foundation of China(32472141,32101746,and 32102231)Natural Science Foundation of Hubei Province(JCZRLH202500540,2021CFB033,and 2022CFB393)。
文摘Rice grain size and chalkiness are important traits that influence grain yield and quality,respectively.Mining of genes for grain yield and appearance quality and clarification of their action modes are of great importance in rice breeding.In this study,a rice protein disulfide isomerase-like enzyme PDIL2-3 was characterized.Expression analysis revealed that PDIL2-3 was highly expressed in endosperm and spikelet hulls.The PDIL2-3-cri lines generated by CRISPR/Cas9 technology exhibited a chalky grain phenotype with altered storage substance accumulation and increased grain size and weight,whereas exactly opposite results were obtained for PDIL2-3 overexpression lines.Cytological experiments revealed that PDIL2-3-cri increased rice seed length mainly by increasing the cell number and rice seed width mainly by increasing the cell size in grains,implying that PDIL2-3 regulates the grain size by influencing both cell division and expansion of spikelet hulls.Further flow cytometric analysis validated that PDIL2-3 has a negative effect on cell proliferation,preventing DNA duplication and cell division in spikelet hulls.Moreover,q RT-PCR results showed that the expression levels of genes related to cell cycle and storage substance synthesis were significantly changed in PDIL2-3-cri transgenic lines.Thus,our results indicated that PDIL2-3 plays a pivotal role in influencing grain size and quality of rice by affecting cell division/expansion and storage substance accumulation,providing new insights into the function of PDIL family members in rice and enriching the genetic resources for rice breeding.
基金Funding for this project was provided by the National Natural Science Foundation of China(Grants No.32160456,32360474,32360486,32260496)the Key Laboratory of Functional Agriculture of Guizhou Provincial Higher Education Institutions(Grant No.Qianjiaoji(2023)007).
文摘Wheat grain morphology,particularly grain length(GL)and width(GW),is a key determinant of yield.To improve the suboptimal grain dimensions of the local anthocyanin-rich variety Guizi 1(GZ1),we crossed it with Zhongyan 96-3(ZY96-3),an elite germplasm known for faster grain filling and superior grain size.A genotyping-by-sequencing(GBS)approach was applied to an F_(2)population of 110 individuals derived from GZ1×ZY96-3,resulting in the identification of 23,134 high-quality SNPs.Most of the SNPs associated with GL and GW were clustered on chromosomes 2B,3A,and 3B.QTL mapping for GL revealed two major loci,GL1 on chromosome 2B and GL2 on chromosome 3B,and eight candidate genes were identified within their corresponding intervals(2B:63.6–70.4 Mb;3B:631.5–633.3 Mb).These genes encode proteins potentially involved in grain size regulation,including a TOR2 regulation-associated protein,erect spike 2(EP2),fibroblast growth factor 6(FGF6),cellulose synthase-like(CSLD),RelA/pot homologue three family protein,and three GDSL esterase/lipase(GLIP)proteins.Additionally,we detected a QTL associated with GW on chromosome 3A and identified two candidate genes,TOR2 regulation and starch synthase within the 61.4–68.5 Mb interval.Overall,this study provides a strong theoretical and technical basis for wheat genetic improvement and offers valuable resources for precise QTL mapping and candidate gene discovery.
基金supported by the China Agriculture Research System of MOF and MARA (CARS-03-19)the National Natural Science Foundation of China (51879267)the Agricultural Science and Technology Innovation Program (ASTIP), Chinese Academy of Agricultural Sciences。
文摘Irrigation methods and nitrogen(N) fertilization modes have complicated impacts on wheat physiology, growth, and development, leading to the regulation of wheat grain yield and quality. However, the optimal water-N combination for drip-irrigated winter wheat remains unclear. A two-year field study was conducted to evaluate the influences of various N-fertigation and water regimes on wheat post-anthesis grain weight variation, yield, grain NPK content, and grain quality. The two irrigation quotas were I_(45)(irrigation when crop evapotranspiration reduced by effective rainfall(ETa-P) reaches 45 mm) and I_(30)(irrigation when ETa-P reaches 30 mm), while the six N application rates were N_(0–100)(100% at jointing/booting), N_(25–75)(25% at sowing and 75% at jointing/booting), N_(50–50)(50% at sowing and 50% at jointing/booting), N_(75–25)(75% at sowing and 25% at jointing/booting), N_(100–0)(100% at sowing), and SRF100(100% of slow-release fertilizer at sowing). The experimental findings showed that post-anthesis grain weight variation, grain yield, grain NPK content, and grain quality were all markedly influenced by the various irrigation schedules and N-fertilization modes. The N_(50–50)treatment was more beneficial for winter wheat post-anthesis grain weight variation than the N_(100–0)and N_(0–100)treatments under the two irrigation quotas and during the two seasons. The highest grain yields of 9.72 and9.94(t ha^(-1)) were obtained with the I_(45)N_(50–50)treatment in 2020–2021 and 2021–2022, respectively. The grain crudeprotein was higher in the I_(45)SRF100treatment during the two seasons. The I_(45)N_(100–0)combination significantly(P<0.05)enhanced the content of grain total starch by 7.30 and 8.23% compared with the I_(45)N_(0–100)and I_(30)N_(0–100)treatments,respectively, during the 2021–2021 season. The I_(45)N_(100–0)treatment significantly(P<0.05) enhanced the content ofgrain total starch concentration by 7.77, 7.62 and 7.88% compared with the I_(45)N_(0–100), I_(30)N_(0–100), and I_(30)N_(25–75)treatments,respectively, in the 2021–2022 season. The principal component analysis(PCA) indicated that the N_(50–50)splitN-fertigation mode could be the optimal choice for farmers during winter wheat production via drip irrigation.
基金supported by National Key Research and Development Program of China(Grant No.2022YFB4602301)the National Natural Science Foundation of China(Grant Nos.52405371,52275381,52174346)+1 种基金the Training Program of Innovation and Entrepreneurship for Undergraduates(Grant No.CXCY2024027)We thank Qian Wang(Northwestern Polytechnical University),Yida Feng(Liaocheng University),Jingdong Ma(Liaocheng University),and Keri Xiaoqiangshiyao(Liaocheng University)for their support of this research.
文摘Although 316L stainless steel(SS316L)exhibits favorable ductility and toughness,its limited strength restricts its applicability.This study addressed this limitation by preparing a series of SS316L-xTC4 alloys(where x indicates Ti6Al4V(TC4)contents of 0.5 wt%,1 wt%,2 wt%,and 4 wt%)with equiaxed grains,ultrafine grains,and heterogeneous structures using in-situ alloying via laser powder bed fusion.The Ti,Al,and V in the TC4 alloy were shown to stabilize and promote the formation of theαphase,which is stronger than theγphase in typical SS316L.Furthermore,these solute elements readily formed nanoparticles with impurities,such as C and O,to increase the nucleation rate and thereby achieve grain refinement.This resulted in the formation of ultrafine grains predominantly within theαphase,where the solute elements were primarily distributed.The formation of theαphase also impeded the growth of theγphase;coupled with the effects of the nanoparticles,this also significantly reduced the grain size in theγphase.Notably,the SS316L-2TC4 alloy exhibited fully equiaxed grains,and the coexistence of theαandγphases as well as ultrafine and coarse grains formed heterogeneous grain and dual-phase structures within.The synergistic effects of equiaxed grains,ultrafine grains,and heterostructures produced an SS316L alloy that exhibited both excellent strength and elongation.
基金supported by the European Union’s Horizon Europe research and innovation programme,Zero Emission electric Vehicles enabled by haRmonised circularity,under No.101138034.
文摘Grain size and formation of the Peripheral Coarse Grain(PCG)defect influence the mechanical and crash properties of extruded profiles.Controlling microstructural evolution during the extrusion of 6XXX series aluminum alloys is therefore essential to ensure the performance of structural components.In this work,three profiles with the same nominal geometry were extruded with a die comprising three different bearing geometries to create different extrusion conditions.Each profile was analyzed experimentally to gather data on the microstructure and mechanical properties.Bulge testing revealed that Profile 2,with the thickest PCG layer(490-1150µm),exhibited worse mechanical performance,with a hoop strain at fracture of 0.08 and a peak load of 51.5 kN,compared to Profiles 1 and 3,which had higher hoop strains(0.13 and 0.14)and peak loads(56.1 and 57.6 kN,respectively).Finite Element Method(FEM)simulations of the extrusion process were carried out using Qform Extrusion UK with a post-processing subroutine developed and implemented to calculate additional parameters such as the stored energy,percentage dynamic recrystallization,grain size,and PCG formation based on standard output parameters from the simulation including strain,temperature and strain rate.The simulation demonstrated that the highest strain rate(40-220 s^(-1))and stored energy(150,000-440,000 J m^(-3))in Profile 2 led to the thickest PCG layer.Based on these results,the proposed predictive model was validated against experimental data,demonstrating high accuracy in predicting PCG thickness and grain size while effectively capturing the influence of process parameters on microstructural evolution.
基金supported by the National Natural Science Foundation of China(U21A20116).
文摘A metallurgical model for austenite coarsening in the coarse-grained heat-affected zone(CGHAZ)containing titanium nitride(TiN)precipitation was studied.Unlike traditional methods estimating pinning capability based on the precipitation size after welding,a proposed dissolution and coarsening model was applied to study the changes in TiN precipitation size and the associated pinning forces.The transmission electron microscope was used to analyze the size distribution of TiN particles before and after the welding thermal cycle.The size distribution showed a log-normal distribution before the thermal cycle.The prediction of post-thermal cycle size distributions with the proposed model was in agreement with the experimental results.Considering the short holding time at high temperature during welding,the thermodynamic stability conditions required for limiting grain size model cannot be achieved.A simple kinetic model for the prediction of austenite grain size in CGHAZ was established.Finally,the predicted austenite grain sizes agree better with experimental results than the conventional approach.
基金National Natural Science Foundation of China(52065036,52365018)Natural Science Foundation of Gansu(23JRRA760)+1 种基金Hongliu Outstanding Youth Foundation of Lanzhou University of TechnologyChina Postdoctoral Science Foundation(2023M733583)。
文摘The scratching mechanism of polycrystallineγ-TiAl alloy was investigated at the atomic scale using the molecular dynamics method,with a focus on the influence of different grain sizes.The analysis encompassed tribological characteristics,scratch morphology,subsurface defect distribution,temperature variations,and stress states during the scratching process.The findings indicate that the scratch force,number of recovered atoms,and pile-up height exhibit abrupt changes when the critical size is 9.41 nm due to the influence of the inverse Hall-Petch effect.Variations in the number of grain boundaries and randomness of grain orientation result in different accumulation patterns on the scratch surface.Notably,single crystal materials and those with 3.73 nm in grain size display more regular surface morphology.Furthermore,smaller grain size leads to an increase in average coefficient of friction,removed atoms number,and wear rate.While it also causes higher temperatures with a larger range of distributions.Due to the barrier effect of grain boundaries,smaller grains exhibit reduced microscopic defects.Additionally,average von Mises stress and hydrostatic compressive stress at the indenter tip decrease as grain size decreases owing to grain boundary obstruction.
基金Key Research and Development Plan of Shaanxi Province(2023-YBGY-493)。
文摘As-forged WSTi6421 titanium alloy billet afterβannealing was investigated.Abnormally coarse grains larger than adjacent grains could be observed in the microstructures,forming abnormal grain structures with uneven size distribution.Through electron backscattered diffraction(EBSD),the forged microstructure at various locations of as-forged WSTi6421 titanium alloy billet was analyzed,revealing that the strength of theβphase cubic texture generated by forging significantly influences the grain size afterβannealing.Heat treatment experiments were conducted within the temperature range from T_(β)−50°C to T_(β)+10°C to observe the macro-and micro-morphologies.Results show that the cubic texture ofβphase caused by forging impacts the texture of the secondaryαphase,which subsequently influences theβphase formed during the post-βannealing process.Moreover,the pinning effect of the residual primaryαphase plays a crucial role in the growth ofβgrains during theβannealing process.EBSD analysis results suggest that the strength ofβphase with cubic texture formed during forging process impacts the orientation distribution differences ofβgrains afterβannealing.Additionally,the development of grains with large orientations within the cubic texture shows a certain degree of selectivity duringβannealing,which is affected by various factors,including the pinning effect of the primaryαphase,the strength of the matrix cubic texture,and the orientation relationship betweenβgrain and matrix.Comprehensively,the stronger the texture in a certain region,the less likely the large misoriented grains suffering secondary growth,thereby aggregating the difference in microstructure and grain orientation distribution across different regions afterβannealing.
