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
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
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-oriented silicon steels were prepared at different heating rates during high temperature annealing,in which the evolution of magnetic properties,grain orientations and precipitates were studied.To illustrate the...Grain-oriented silicon steels were prepared at different heating rates during high temperature annealing,in which the evolution of magnetic properties,grain orientations and precipitates were studied.To illustrate the Zener factor,the diameter and number density of precipitates of interrupted testing samples were statistically calculated.The effect of precipitate ripening on the Goss texture and magnetic property was investigated.Data indicated that the trend of Zener factor was similar under different heating rates,first increasing and then decreasing,and that the precipitate maturing was greatly inhibited as the heating rate increased.Secondary recrystallization was developed at the temperature of 1010℃when a heating rate of 5℃/h was used,resulting in Goss,Brass and{110}<227>oriented grains growing abnormally and a magnetic induction intensity of 1.90T.Furthermore,increasing the heating rate to 20℃/h would inhibit the development of undesirable oriented grains and obtain a sharp Goss texture.However,when the heating rate was extremely fast,such as 40℃/h,poor secondary recrystallization was developed with many island grains,corresponding to a decrease in magnetic induction intensity to 1.87 T.At a suitable heating rate of 20℃/h,the sharpest Goss texture and the highest magnetic induction of 1.94 T with an onset secondary recrystallization temperature of 1020℃were found among the experimental variables in this study.The heating rate affected the initial temperature of secondary recrystallization by controlling the maturation of precipitates,leading to the deviation and dispersion of Goss texture,thereby reducing the magnetic properties.展开更多
Sorghum is an important cereal crop for smallholder farmers’ food security in many countries in West Africa. However, its production has stagnated due to several factors, such as anthracnose and grain molds. Thus, a ...Sorghum is an important cereal crop for smallholder farmers’ food security in many countries in West Africa. However, its production has stagnated due to several factors, such as anthracnose and grain molds. Thus, a study was conducted to identify local germplasms that combine high grain yield and resistance to anthracnose and grain molds under Senegalese environments. A set of 256 genotypes was assessed at Sefa, Sinthiou and Kolda research stations using an incomplete blocks design with two replications. Agro-morphological and phytopathological data were collected. The results revealed a huge phenotypic variation between the genotypes for all traits. The flowering time varied from 43 to 126 days after sowing, while the panicle length varied from 10 to 60 cm. The genotypes were generally more productive at Sinthiou (1653 Kg ha−1) compared to Kolda (164 kg ha−1) research stations. The disease parameters were significantly and positively associated, while the flowering time was strongly and positively associated to grain mold score. The genotypes were classified into three groups with plant height, panicle diameter and length, flowering time and grain mold score as the most discriminating parameters. The genotypes belonging to cluster 3, in addition of being more productive and more resistant to grain mold and anthracnose, have longer panicles. These genotypes present promising prospects for inclusion in breeding programs focused on advancing sorghum yield and disease resistance in Senegal.展开更多
Increasing concern over the amount of insecticide residues in food has encouraged research for ecologically sound strategies to effectively manage stored-product insect pests and protect living organisms and the envir...Increasing concern over the amount of insecticide residues in food has encouraged research for ecologically sound strategies to effectively manage stored-product insect pests and protect living organisms and the environment. Botanicals were evaluated as potential alternatives to control maize weevil, Sitophilus zeamais Motschulsky, in stored sorghum, Sorghum bicolor (L.) Moench. Beetles and moths of stored grain at farm and consumer levels damage 5 - 35% worldwide and >40% in tropical countries. Maize weevil is the most damaging storage insect of sorghum grain. Management of storage insects relies on insecticides that leave residues in food and the environment. Treatments were powders of neem bark, Azadirachta indica;mesquite pods, Prosopis glandulosa;milkweed leaves, Asclepias speciosa;and a check (no botanical powder). Eight newly emerged maize weevils were provided 5 g of Malisor-84 grain treated with three doses of each plant powder. Every 2 days, data were recorded on the number of adults killed by each treatment. Percentage killed was calculated by dose per treatment and compared with the check. Grain loss was calculated based on initial and final weights. LD50 was determined by probit analysis, and associations between variables were assessed by simple linear correlation. Powder of mesquite and milkweed at 0.2 g were more effective than neem or the check in killing S. zeamais (>90%) and reducing grain damage (34 - 35.2%) and weight loss (0.8%). Milkweed at 0.1 g and neem at 0.2 g killed 78.1% of weevils. Neem at 0.05 g was slow acting, resulting in 62.5% dead and more grain damage (59.5%) and weight loss (3.6%). Botanicals at low doses (LD50 = 0.2 - 0.4 g) showed efficacy in controlling maize weevils and are recommended alternatives to guarantee quantity and quality of stored cereal grains.展开更多
Conventional rolled Mg-Al alloy sheets typically exhibit strong basal textures that remain and may even strengthen after recrystallization annealing due to the preferential growth of basal-oriented grains,resulting in...Conventional rolled Mg-Al alloy sheets typically exhibit strong basal textures that remain and may even strengthen after recrystallization annealing due to the preferential growth of basal-oriented grains,resulting in poor formability at room temperature.Therefore,the knowledge of recrystallization and grain growth is critical for modifying textures of Mg-Al alloy sheets.The static recrystallization and texture evolution in a cold-rolled dilute Mg-1Al(wt.%)alloy during various annealed temperatures ranging from 300℃ to 450℃,have been investigated using the quasi in-situ electron backscatter diffraction(EBSD)method.The as-rolled Mg-1Al alloy shows a dominant basal texture,which weakens and broadens in the rolling direction(RD)during the subsequent annealing,accompanied by the formation of{1010}texture component.Particularly,the {1010} texture component is more pronounced after annealing at high temperatures.The quasi in-situ EBSD results show that recrystallized grains are mainly induced by shear bands,which exhibit a wide spectrum of orientations with c-axis tilt angles ranging 20°-45°from the normal direction(ND).Orientations of shear band-induced recrystallized grains are retained during the entire recrystallization process,resulting in a reduction in the texture intensity.Moreover,recrystallized grains belonging to the {1010}texture component grow preferentially compared to those with other orientations,which is attributed to low energy grain boundaries,especially grain boundaries with∼30°misorientation angles.Furthermore,the high temperature annealing facilitates the rapid growth of grain boundaries having a 30°misorientation angle,leading to the occurrence of distinct {1010} texture after annealing at 450℃ for 1 h.The results provide insights for texture modification of rare earth-free low-alloyed Mg alloys by controlling annealing parameters.展开更多
Low temperature(LT)in spring has become one of the principal abiotic stresses that restrict the growth and development of wheat.Diverse analyses were performed to investigate the mechanism underlying the response of w...Low temperature(LT)in spring has become one of the principal abiotic stresses that restrict the growth and development of wheat.Diverse analyses were performed to investigate the mechanism underlying the response of wheat grain development to LT stress during booting.These included morphological observation,measurements of starch synthase activity,and determination of amylose and amylopectin content of wheat grain after exposure to treatment with LT during booting.Additionally,proteomic analysis was performed using tandem mass tags(TMT).Results showed that the plumpness of wheat grains decreased after LT stress.Moreover,the activities of sucrose synthase(SuS,EC 2.4.1.13)and ADP-glucose pyrophosphorylase(AGPase,EC 2.7.7.27)exhibited a significant reduction,leading to a significant reduction in the contents of amylose and amylopectin.A total of 509 differentially expressed proteins(DEPs)were identified by proteomics analysis.The Gene Ontology(GO)enrichment analysis showed that the protein difference multiple in the nutritional repository activity was the largest among the molecular functions,and the up-regulated seed storage protein(ssP)played an active role in the response of grains to LT stress and subsequent damage.The Kyoto Encyclopedia of Genes and Genomes(KEGG)enrichment analysis showed that LT stress reduced the expression of DEPs such as sucrose phosphate synthase(SPS),glucose-1-phosphate adenylyltransferase(glgC),andβ-fructofuranosidase(FFase)in sucrose and starch metabolic pathways,thus affecting the synthesis of grain starch.In addition,many heat shock proteins(HsPs)were found in the protein processing in endoplasmic reticulum pathways,which can resist some damage caused by LT stress.These findings provide a new theoretical foundation for elucidating the underlying mechanism governing wheat yield developmentafterexposuretoLTstress inspring.展开更多
Rice is a well-recognized accumulator of arsenic(As),which poses a threat to food security and human health.Different rice varieties vary widely in their As accumulation and tolerance,yet the underlying genetic basis ...Rice is a well-recognized accumulator of arsenic(As),which poses a threat to food security and human health.Different rice varieties vary widely in their As accumulation and tolerance,yet the underlying genetic basis remains unknown.In this study,we isolated a rice mutant hag1,which displayed high accumulation of As in rice grains and increased sensitivity to As toxicity.Using genetic investigation,we identified the ATP-binding cassette(ABC)transporter OsABCC1,involved in sequestering As in vacuoles,as the causal gene responsible for As allocation and tolerance in rice.Detailed physiological analysis revealed that As stress caused more severe oxidative damage in hag1 compared with the wild type(WT).The hag1 mutant displayed different accumulation patterns depending on the levels of As stress.We discovered that under low As concentration,hag1 synthesized more thiol compounds and exhibited lower As translocation than the WT;however,at high As levels,hag1 produced fewer thiol compounds and increased As transfer factor.Transcriptome analysis of the node nearest to the panicles revealed that OsABCC1 was down-regulated in hag1,resulting in increased As translocation and accumulation in rice grains.Additionally,natural variations in the promoter of OsABCC1 may confer differential gene expression and distinct As accumulations in grains between japonica and indica rice varieties,providing insights for breeding low-As rice varieties.展开更多
The mineralogy and texture of granite have been found to have a pronounced effect on its mechanical behavior.However,the precise manner in which the texture of granite affects the shear behavior of fractures remains e...The mineralogy and texture of granite have been found to have a pronounced effect on its mechanical behavior.However,the precise manner in which the texture of granite affects the shear behavior of fractures remains enigmatic.In this study,fine-grained granite(FG)and coarse-grained granite(CG)were used to create tensile fractures with surface roughness(i.e.joint roughness coefficient(JRC))within the range of 5.48-8.34 and 12.68-16.5,respectively.The pre-fractured specimens were then subjected to direct shear tests under normal stresses of 1-30 MPa.The results reveal that shear strengths are smaller and stick-slip behaviors are more intense for FG fractures than for CG fractures,which is attributed to the different conditions of the shear surface constrained by the grain size.The smaller grain size in FG contributes to the smoother fracture surface and lower shear strength.The negative friction rate parameter a-b for both CG and FG fractures and the larger shear stiffness for FG than for CG fractures can account for the more intense stick-slip behaviors in FG fractures.The relative crack density for the post-shear CG fractures is greater than that of the FG fractures under the same normal stress,both of which decrease with the distance away from the shear surface following the power law.Moreover,the damage of CG fracture extends to a larger extent beneath the surface compared with the FG fracture.Our findings demonstrate that the grain size of the host rock exerts a significant influence on the fracture roughness,and thus should be incorporated into the assessment of fault slip behavior to better understand the role of mineralogy and texture in seismic activities.展开更多
Rice leaf morphology is of great significance in the breeding of an ideal plant type and high photosynthetic efficiency.A forward genetics approach was employed to locate a novel gene,NRL9(NARROW AND ROLLED LEAF 9).NR...Rice leaf morphology is of great significance in the breeding of an ideal plant type and high photosynthetic efficiency.A forward genetics approach was employed to locate a novel gene,NRL9(NARROW AND ROLLED LEAF 9).NRL9 encodes a 20S proteasome β1 subunit and is involved in regulating leaf morphology and grain size.Compared with the wild type(WT),the nrl9 mutant exhibited a significant decrease in leaf width,and a significant increase in leaf rolling index(LRI),while also displaying increased grain length and decreased grain width.展开更多
Garnet lithium lanthanum zirconium oxide(Li_(7)La_(3)Zr_(2)O_(12),LLZO)is a benchmark solid-state electrolyte(SSE)material receiving considerable attention owing to its high conductivity and chemical stability against...Garnet lithium lanthanum zirconium oxide(Li_(7)La_(3)Zr_(2)O_(12),LLZO)is a benchmark solid-state electrolyte(SSE)material receiving considerable attention owing to its high conductivity and chemical stability against Li metal.Although its electro-chemo-mechanical failure mechanisms have been much investigated,the equivocal roles of grain boundary strength and grain size of LLZO remain under-explored,hindering further performance improvements.Here we decoupled the effects of grain size and grain boundary strength of polycrystalline LLZO via the combination of electrochemical kinetics and the cohesive zone model.We discovered that the disintegration of LLZO is initiated by the accumulation of local displacements,which strongly relates to the changes in both grain size and grain boundary strength.However,variations in grain boundary strength affect the diffusion and propagation pathways of damage,while the failure of LLZO is determined by the grain size.Large LLZO grains facilitate transgranular damage under low grain boundary strength,which can alter local chemo-mechanics within the bulk of LLZO,leading to more extensive damage propagation.The results showcase the structure optimization pathways by preferentially controlling the growth of lithium dendrites at grain boundaries and their penetration in garnet-type SSE.展开更多
The dynamic mechanical response and deformation mechanism of magnesium-yttrium alloy at high strain rate were investigated using split-Hopkinson pressure bar(SHPB)impact,and the microstructure evolution and crack form...The dynamic mechanical response and deformation mechanism of magnesium-yttrium alloy at high strain rate were investigated using split-Hopkinson pressure bar(SHPB)impact,and the microstructure evolution and crack formation mechanism were revealed.The yield strength and work hardening rate increase significantly with increasing impact strain rate.Deformation twinning and non-basal dislocation slip are the primary deformation mechanisms during testing.Contrary to crack initiation mechanism facilitated by adiabatic shear bands,we find that high-density co-axial nanocrystalline grains form near cracks,which leads to local softening and promotes crack initiation and rapid propagation.Most grains have similar<1^(-)21^(-)0>orientations,with unique misorientation of 24°,32°,62°,78°and 90°between adjacent grains,suggesting that these grains are primarily formed by interface transformation,which exhibits distinct differences from recrystallized grains.Our results shed light upon the dynamic mechanical response and crack formation mechanism in magnesium alloys under impact deformation.展开更多
In order to accurately evaluate the creep-fatigue lifetime of GH720Li superalloy,a lifetime prediction model was established,reflecting the interaction between creep damage and low-cycle fatigue damage.The creep-fatig...In order to accurately evaluate the creep-fatigue lifetime of GH720Li superalloy,a lifetime prediction model was established,reflecting the interaction between creep damage and low-cycle fatigue damage.The creep-fatigue lifetime prediction results of GH720Li superalloy with an average grain size of 17.3μm were essentially within a scatter band of 2 times,indicating a strong agreement between the predicted lifetimes and experimental data.Then,considering that the grain size of the dual-property turbine disc decreases from the rim to the center,a grain-size-sensitive lifetime prediction model for creep-fatigue was established by introducing the ratio of grain boundary area.The improved model overcame the limitation of most traditional prediction methods,which failed to reflect the relationship between grain size and creep-fatigue lifetime.展开更多
This study aims to clarify the mechanisms for the grain boundary(GB)segregation through investigating the absorption of excess solute atoms at GBs in Al−Cu alloys by using the hybrid molecular dynamics/Monte Carlo sim...This study aims to clarify the mechanisms for the grain boundary(GB)segregation through investigating the absorption of excess solute atoms at GBs in Al−Cu alloys by using the hybrid molecular dynamics/Monte Carlo simulations.Two segregation mechanisms,substitutional and interstitial mechanisms,are observed.The intergranular defects,including dislocations,steps and vacancies,and the intervals in structural units are conductive to the prevalence of interstitial mechanism.And substitutional mechanism is favored by the highly ordered twin GBs.Furthermore,the two mechanisms affect the GB structure differently.It is quantified that interstitial mechanism is less destructive to GB structure than substitutional one,and often leads to a segregation level being up to about 6 times higher than the latter.These findings contribute to atomic scale insights into the microscopic mechanisms about how solute atoms are absorbed by GB structures,and clarify the correlation among intergranular structures,segregation mechanisms and kinetics.展开更多
Sorghum,a drought-resistant cereal crop crucial for global food security,typically produces single seeds per spikelet.A team of researchers from the Institute of Genetics and Developmental Biology(IGDB)of the Chinese ...Sorghum,a drought-resistant cereal crop crucial for global food security,typically produces single seeds per spikelet.A team of researchers from the Institute of Genetics and Developmental Biology(IGDB)of the Chinese Academy of Sciences and the Sun Yat-sen University in Guangzhou recently identified a genetic mechanism that enables some varieties to develop double-grain spikelets,significantly boosting yields.By analyzing three genetic populations,scientists traced this trait to a 35.7-kilobase chromosomal inversion activating DG1-a gene that encodes a protein regulating floral meristem development.展开更多
The size and shape of rice grains influence their yield and commercial value.We investigated the role of OsDA1,a rice homolog of the Arabidopsis DA1 gene,in regulating grain size and shape.OsDA1 was highly expressed i...The size and shape of rice grains influence their yield and commercial value.We investigated the role of OsDA1,a rice homolog of the Arabidopsis DA1 gene,in regulating grain size and shape.OsDA1 was highly expressed in young spikelets and glumes.Its overexpression led to enlarged seeds with increased width and decreased length/width ratio(LWR)and knocking out OsDA1 reduced grain width and increased grain length and LWR.A R310K point mutation in the DA1-like domain is a potential target for breeding for increased grain width and length.OsDA1 interacted with TCP gene-family proteins to regulate grain size and shape.Our findings deepen our understanding of the molecular mechanisms underlying grain size regulation and provide useful information for improving grain yield.展开更多
Ferritic/martensitic(F/M)steel is widely used as a structural material in thermal and nuclear power plants.However,it is susceptible to intergranular damage,which is a critical issue,under service conditions.In this s...Ferritic/martensitic(F/M)steel is widely used as a structural material in thermal and nuclear power plants.However,it is susceptible to intergranular damage,which is a critical issue,under service conditions.In this study,to improve the resistance to intergranular damage of F/M steel,a thermomechanical process(TMP)was employed to achieve a grain boundary engineering(GBE)microstructure in F/M steel P92.The TMP,including cold-rolling thickness reduction of 6%,9%,and 12%,followed by austenitization at 1323 K for 40 min and tempering at 1053 K for 45 min,was applied to the as-received(AR)P92 steel.The prior austenite grain(PAG)size,prior austenite grain boundary character distribution(GBCD),and connectivity of prior austenite grain boundaries(PAGBs)were investigated.Compared to the AR specimen,the PAG size did not change significantly.The fraction of coincident site lattice boundaries(CSLBs,3≤Σ≤29)and Σ3^(n) boundaries along PAGBs decreased with increasing reduction ratio because the recrystallization fraction increased with increasing reduction ratio.The PAGB connectivity of the 6%deformed specimen slightly deteriorated compared with that of the AR specimen.Moreover,potentiodynamic polarization studies revealed that the intergranular damage resistance of the studied steel could be improved by increasing the fraction of CSLBs along the PAGBs,indicating that the TMP,which involves low deformation,could enhance the intergranular damage resistance.展开更多
The superplastic behavior and associated deformation mechanisms of a fine-grained Mg-10.1 Li-0.8Al-0.6Zn alloy(LAZ1011)with a grain size of 3.2μm,primarily composed of the BCCβphase and a small amount of the HCPαph...The superplastic behavior and associated deformation mechanisms of a fine-grained Mg-10.1 Li-0.8Al-0.6Zn alloy(LAZ1011)with a grain size of 3.2μm,primarily composed of the BCCβphase and a small amount of the HCPαphase,were examined in a temperature range of 473 K to 623 K.The microstructural refinement of this alloy was achieved by employing high-ratio differential speed rolling.The best superplasticity was achieved at 523 K and at strain rates of 10^(-4)-5×10^(-4)s^(-1),where tensile elongations of 550±600%were obtained.During the heating and holding stage of the tensile samples prior to tensile loading,a significant increase in grain size was observed at temperatures above 573 K.Therefore,it was important to consider this effect when analyzing and understanding the superplastic deformation behavior and mechanisms.In the investigated strain rate range,the superplastic flow at low strain rates was governed by lattice diffusion-controlled grain boundary sliding,while at high strain rates,lattice diffusion-controlled dislocation climb creep was the rate-controlling deformation mechanism.It was concluded that solute drag creep is unlikely to occur.During the late stages of deformation at 523 K,it was observed that grain boundary sliding led to the agglomeration of theαphase,resulting in significant strain hardening.Deformation mechanism maps were constructed forβ-Mg-Li alloys in the form of 2D and 3D formats as a function of strain rate,stress,temperature,and grain size,using the constitutive equations for various deformation mechanisms derived based on the data of the current tests.展开更多
Grain size is a key factor influencing grain weight in rice.In this study,a chromosome segment substitution line(CSSL9-17)was identified,that exhibits a significant reduction in both grain size and weight compared to ...Grain size is a key factor influencing grain weight in rice.In this study,a chromosome segment substitution line(CSSL9-17)was identified,that exhibits a significant reduction in both grain size and weight compared to its donor parent 93-11.Further investigation identified two quantitative trait loci(QTL)on chromosome 11,designated qGW11a and qGW11b,which contribute to 1000-grain weight with an additive effect.LOC_Os11g05690,encoding the amino acid permease OsCAT8,is the target gene of qGW11a.Overexpression of OsCAT8 resulted in decreased grain weight,while OsCAT8 knockout mutants exhibited increased grain weight.The 287-bp located within the OsCAT8 promoter region of 93-11 negatively regulates its activity,which is subsequently correlated with an increase in grain size and weight.These results suggest that OsCAT8 functions as a negative regulator of grain size and grain weight in rice.展开更多
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.
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.
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.
文摘Grain-oriented silicon steels were prepared at different heating rates during high temperature annealing,in which the evolution of magnetic properties,grain orientations and precipitates were studied.To illustrate the Zener factor,the diameter and number density of precipitates of interrupted testing samples were statistically calculated.The effect of precipitate ripening on the Goss texture and magnetic property was investigated.Data indicated that the trend of Zener factor was similar under different heating rates,first increasing and then decreasing,and that the precipitate maturing was greatly inhibited as the heating rate increased.Secondary recrystallization was developed at the temperature of 1010℃when a heating rate of 5℃/h was used,resulting in Goss,Brass and{110}<227>oriented grains growing abnormally and a magnetic induction intensity of 1.90T.Furthermore,increasing the heating rate to 20℃/h would inhibit the development of undesirable oriented grains and obtain a sharp Goss texture.However,when the heating rate was extremely fast,such as 40℃/h,poor secondary recrystallization was developed with many island grains,corresponding to a decrease in magnetic induction intensity to 1.87 T.At a suitable heating rate of 20℃/h,the sharpest Goss texture and the highest magnetic induction of 1.94 T with an onset secondary recrystallization temperature of 1020℃were found among the experimental variables in this study.The heating rate affected the initial temperature of secondary recrystallization by controlling the maturation of precipitates,leading to the deviation and dispersion of Goss texture,thereby reducing the magnetic properties.
文摘Sorghum is an important cereal crop for smallholder farmers’ food security in many countries in West Africa. However, its production has stagnated due to several factors, such as anthracnose and grain molds. Thus, a study was conducted to identify local germplasms that combine high grain yield and resistance to anthracnose and grain molds under Senegalese environments. A set of 256 genotypes was assessed at Sefa, Sinthiou and Kolda research stations using an incomplete blocks design with two replications. Agro-morphological and phytopathological data were collected. The results revealed a huge phenotypic variation between the genotypes for all traits. The flowering time varied from 43 to 126 days after sowing, while the panicle length varied from 10 to 60 cm. The genotypes were generally more productive at Sinthiou (1653 Kg ha−1) compared to Kolda (164 kg ha−1) research stations. The disease parameters were significantly and positively associated, while the flowering time was strongly and positively associated to grain mold score. The genotypes were classified into three groups with plant height, panicle diameter and length, flowering time and grain mold score as the most discriminating parameters. The genotypes belonging to cluster 3, in addition of being more productive and more resistant to grain mold and anthracnose, have longer panicles. These genotypes present promising prospects for inclusion in breeding programs focused on advancing sorghum yield and disease resistance in Senegal.
文摘Increasing concern over the amount of insecticide residues in food has encouraged research for ecologically sound strategies to effectively manage stored-product insect pests and protect living organisms and the environment. Botanicals were evaluated as potential alternatives to control maize weevil, Sitophilus zeamais Motschulsky, in stored sorghum, Sorghum bicolor (L.) Moench. Beetles and moths of stored grain at farm and consumer levels damage 5 - 35% worldwide and >40% in tropical countries. Maize weevil is the most damaging storage insect of sorghum grain. Management of storage insects relies on insecticides that leave residues in food and the environment. Treatments were powders of neem bark, Azadirachta indica;mesquite pods, Prosopis glandulosa;milkweed leaves, Asclepias speciosa;and a check (no botanical powder). Eight newly emerged maize weevils were provided 5 g of Malisor-84 grain treated with three doses of each plant powder. Every 2 days, data were recorded on the number of adults killed by each treatment. Percentage killed was calculated by dose per treatment and compared with the check. Grain loss was calculated based on initial and final weights. LD50 was determined by probit analysis, and associations between variables were assessed by simple linear correlation. Powder of mesquite and milkweed at 0.2 g were more effective than neem or the check in killing S. zeamais (>90%) and reducing grain damage (34 - 35.2%) and weight loss (0.8%). Milkweed at 0.1 g and neem at 0.2 g killed 78.1% of weevils. Neem at 0.05 g was slow acting, resulting in 62.5% dead and more grain damage (59.5%) and weight loss (3.6%). Botanicals at low doses (LD50 = 0.2 - 0.4 g) showed efficacy in controlling maize weevils and are recommended alternatives to guarantee quantity and quality of stored cereal grains.
基金by National Natural Science Foundation of China(Nos.52271103,52334010 and 52271031)Jilin Scientific and Technological Development Program(Nos.20220301026GX,20210201115GX and 20210301041GX).
文摘Conventional rolled Mg-Al alloy sheets typically exhibit strong basal textures that remain and may even strengthen after recrystallization annealing due to the preferential growth of basal-oriented grains,resulting in poor formability at room temperature.Therefore,the knowledge of recrystallization and grain growth is critical for modifying textures of Mg-Al alloy sheets.The static recrystallization and texture evolution in a cold-rolled dilute Mg-1Al(wt.%)alloy during various annealed temperatures ranging from 300℃ to 450℃,have been investigated using the quasi in-situ electron backscatter diffraction(EBSD)method.The as-rolled Mg-1Al alloy shows a dominant basal texture,which weakens and broadens in the rolling direction(RD)during the subsequent annealing,accompanied by the formation of{1010}texture component.Particularly,the {1010} texture component is more pronounced after annealing at high temperatures.The quasi in-situ EBSD results show that recrystallized grains are mainly induced by shear bands,which exhibit a wide spectrum of orientations with c-axis tilt angles ranging 20°-45°from the normal direction(ND).Orientations of shear band-induced recrystallized grains are retained during the entire recrystallization process,resulting in a reduction in the texture intensity.Moreover,recrystallized grains belonging to the {1010}texture component grow preferentially compared to those with other orientations,which is attributed to low energy grain boundaries,especially grain boundaries with∼30°misorientation angles.Furthermore,the high temperature annealing facilitates the rapid growth of grain boundaries having a 30°misorientation angle,leading to the occurrence of distinct {1010} texture after annealing at 450℃ for 1 h.The results provide insights for texture modification of rare earth-free low-alloyed Mg alloys by controlling annealing parameters.
基金supported by the National Natural Science Foundation of China(32372223)the National Key Research and Development Program of China(2022YFD2301404)+1 种基金the College Students'Innovationand Entrepreneurship Training Program of Anhui Province,China(S202210364136)the Natural Science Research Project of Anhui Educational Committee,China(2023AH040133).
文摘Low temperature(LT)in spring has become one of the principal abiotic stresses that restrict the growth and development of wheat.Diverse analyses were performed to investigate the mechanism underlying the response of wheat grain development to LT stress during booting.These included morphological observation,measurements of starch synthase activity,and determination of amylose and amylopectin content of wheat grain after exposure to treatment with LT during booting.Additionally,proteomic analysis was performed using tandem mass tags(TMT).Results showed that the plumpness of wheat grains decreased after LT stress.Moreover,the activities of sucrose synthase(SuS,EC 2.4.1.13)and ADP-glucose pyrophosphorylase(AGPase,EC 2.7.7.27)exhibited a significant reduction,leading to a significant reduction in the contents of amylose and amylopectin.A total of 509 differentially expressed proteins(DEPs)were identified by proteomics analysis.The Gene Ontology(GO)enrichment analysis showed that the protein difference multiple in the nutritional repository activity was the largest among the molecular functions,and the up-regulated seed storage protein(ssP)played an active role in the response of grains to LT stress and subsequent damage.The Kyoto Encyclopedia of Genes and Genomes(KEGG)enrichment analysis showed that LT stress reduced the expression of DEPs such as sucrose phosphate synthase(SPS),glucose-1-phosphate adenylyltransferase(glgC),andβ-fructofuranosidase(FFase)in sucrose and starch metabolic pathways,thus affecting the synthesis of grain starch.In addition,many heat shock proteins(HsPs)were found in the protein processing in endoplasmic reticulum pathways,which can resist some damage caused by LT stress.These findings provide a new theoretical foundation for elucidating the underlying mechanism governing wheat yield developmentafterexposuretoLTstress inspring.
基金supported by the earmarked fund for‘Pioneer’and‘Leading Goose’R&D Program of Zhejiang Province,China(Grant No.2023C02014)the Central Public Interest Scientific Institution Basal Research Fund for the China National Rice Research Institute(Grant No.CPSIBRF-CNRRI-202407).
文摘Rice is a well-recognized accumulator of arsenic(As),which poses a threat to food security and human health.Different rice varieties vary widely in their As accumulation and tolerance,yet the underlying genetic basis remains unknown.In this study,we isolated a rice mutant hag1,which displayed high accumulation of As in rice grains and increased sensitivity to As toxicity.Using genetic investigation,we identified the ATP-binding cassette(ABC)transporter OsABCC1,involved in sequestering As in vacuoles,as the causal gene responsible for As allocation and tolerance in rice.Detailed physiological analysis revealed that As stress caused more severe oxidative damage in hag1 compared with the wild type(WT).The hag1 mutant displayed different accumulation patterns depending on the levels of As stress.We discovered that under low As concentration,hag1 synthesized more thiol compounds and exhibited lower As translocation than the WT;however,at high As levels,hag1 produced fewer thiol compounds and increased As transfer factor.Transcriptome analysis of the node nearest to the panicles revealed that OsABCC1 was down-regulated in hag1,resulting in increased As translocation and accumulation in rice grains.Additionally,natural variations in the promoter of OsABCC1 may confer differential gene expression and distinct As accumulations in grains between japonica and indica rice varieties,providing insights for breeding low-As rice varieties.
基金the National Natural Science Foundation of China(Grant No.52309130)the Natural Science Foundation of Shandong Province(Grant No.ZR2022QD004).
文摘The mineralogy and texture of granite have been found to have a pronounced effect on its mechanical behavior.However,the precise manner in which the texture of granite affects the shear behavior of fractures remains enigmatic.In this study,fine-grained granite(FG)and coarse-grained granite(CG)were used to create tensile fractures with surface roughness(i.e.joint roughness coefficient(JRC))within the range of 5.48-8.34 and 12.68-16.5,respectively.The pre-fractured specimens were then subjected to direct shear tests under normal stresses of 1-30 MPa.The results reveal that shear strengths are smaller and stick-slip behaviors are more intense for FG fractures than for CG fractures,which is attributed to the different conditions of the shear surface constrained by the grain size.The smaller grain size in FG contributes to the smoother fracture surface and lower shear strength.The negative friction rate parameter a-b for both CG and FG fractures and the larger shear stiffness for FG than for CG fractures can account for the more intense stick-slip behaviors in FG fractures.The relative crack density for the post-shear CG fractures is greater than that of the FG fractures under the same normal stress,both of which decrease with the distance away from the shear surface following the power law.Moreover,the damage of CG fracture extends to a larger extent beneath the surface compared with the FG fracture.Our findings demonstrate that the grain size of the host rock exerts a significant influence on the fracture roughness,and thus should be incorporated into the assessment of fault slip behavior to better understand the role of mineralogy and texture in seismic activities.
基金supported by the National Major Science and Technology Program on New Genetically Modified Organism Variety Breeding,China(Grant No.2016ZX08001-001).
文摘Rice leaf morphology is of great significance in the breeding of an ideal plant type and high photosynthetic efficiency.A forward genetics approach was employed to locate a novel gene,NRL9(NARROW AND ROLLED LEAF 9).NRL9 encodes a 20S proteasome β1 subunit and is involved in regulating leaf morphology and grain size.Compared with the wild type(WT),the nrl9 mutant exhibited a significant decrease in leaf width,and a significant increase in leaf rolling index(LRI),while also displaying increased grain length and decreased grain width.
基金the financial support from the National Natural Science Foundation of China(12102328,52104312,22278329)the Qin Chuangyuan Talent Project of Shaanxi Province(2021QCYRC4-43,QCYRCXM-2022-308)the Fundamental Research Funds for the Central Universities,China.
文摘Garnet lithium lanthanum zirconium oxide(Li_(7)La_(3)Zr_(2)O_(12),LLZO)is a benchmark solid-state electrolyte(SSE)material receiving considerable attention owing to its high conductivity and chemical stability against Li metal.Although its electro-chemo-mechanical failure mechanisms have been much investigated,the equivocal roles of grain boundary strength and grain size of LLZO remain under-explored,hindering further performance improvements.Here we decoupled the effects of grain size and grain boundary strength of polycrystalline LLZO via the combination of electrochemical kinetics and the cohesive zone model.We discovered that the disintegration of LLZO is initiated by the accumulation of local displacements,which strongly relates to the changes in both grain size and grain boundary strength.However,variations in grain boundary strength affect the diffusion and propagation pathways of damage,while the failure of LLZO is determined by the grain size.Large LLZO grains facilitate transgranular damage under low grain boundary strength,which can alter local chemo-mechanics within the bulk of LLZO,leading to more extensive damage propagation.The results showcase the structure optimization pathways by preferentially controlling the growth of lithium dendrites at grain boundaries and their penetration in garnet-type SSE.
基金support from the National Natural Science Foundation of China(Grant Nos.52301137,51974097,52364050)the Natural Science Special Foundation of Guizhou University(No.(2023)20)+1 种基金Guizhou Province Science and Technology Project(Grant Nos.[2023]001,[2019]2163)Guiyang city Science and Technology Project(Grant No.[2023]48-16).
文摘The dynamic mechanical response and deformation mechanism of magnesium-yttrium alloy at high strain rate were investigated using split-Hopkinson pressure bar(SHPB)impact,and the microstructure evolution and crack formation mechanism were revealed.The yield strength and work hardening rate increase significantly with increasing impact strain rate.Deformation twinning and non-basal dislocation slip are the primary deformation mechanisms during testing.Contrary to crack initiation mechanism facilitated by adiabatic shear bands,we find that high-density co-axial nanocrystalline grains form near cracks,which leads to local softening and promotes crack initiation and rapid propagation.Most grains have similar<1^(-)21^(-)0>orientations,with unique misorientation of 24°,32°,62°,78°and 90°between adjacent grains,suggesting that these grains are primarily formed by interface transformation,which exhibits distinct differences from recrystallized grains.Our results shed light upon the dynamic mechanical response and crack formation mechanism in magnesium alloys under impact deformation.
基金financially supported by the National Natural Science Foundation of China(Nos.52306183,12272245,11832007,12172238)the Natural Science Foundation of Zhejiang Province,China(No.LQ23E050022)+1 种基金the Natural Science Foundation of Sichuan Province,China(Nos.2022NSFSC0324,2022JDJQ0011)the Open Project of Failure Mechanics and Engineering Disaster Prevention,Key Laboratory of Sichuan Province,China(No.FMEDP202305)。
文摘In order to accurately evaluate the creep-fatigue lifetime of GH720Li superalloy,a lifetime prediction model was established,reflecting the interaction between creep damage and low-cycle fatigue damage.The creep-fatigue lifetime prediction results of GH720Li superalloy with an average grain size of 17.3μm were essentially within a scatter band of 2 times,indicating a strong agreement between the predicted lifetimes and experimental data.Then,considering that the grain size of the dual-property turbine disc decreases from the rim to the center,a grain-size-sensitive lifetime prediction model for creep-fatigue was established by introducing the ratio of grain boundary area.The improved model overcame the limitation of most traditional prediction methods,which failed to reflect the relationship between grain size and creep-fatigue lifetime.
基金supported by grants from the National Natural Science Foundation of China(Nos.52031017,51801237)the National Key Laboratory of Science and Technology on High-strength Structural Materials in Central South University,China(No.6142912200106).
文摘This study aims to clarify the mechanisms for the grain boundary(GB)segregation through investigating the absorption of excess solute atoms at GBs in Al−Cu alloys by using the hybrid molecular dynamics/Monte Carlo simulations.Two segregation mechanisms,substitutional and interstitial mechanisms,are observed.The intergranular defects,including dislocations,steps and vacancies,and the intervals in structural units are conductive to the prevalence of interstitial mechanism.And substitutional mechanism is favored by the highly ordered twin GBs.Furthermore,the two mechanisms affect the GB structure differently.It is quantified that interstitial mechanism is less destructive to GB structure than substitutional one,and often leads to a segregation level being up to about 6 times higher than the latter.These findings contribute to atomic scale insights into the microscopic mechanisms about how solute atoms are absorbed by GB structures,and clarify the correlation among intergranular structures,segregation mechanisms and kinetics.
文摘Sorghum,a drought-resistant cereal crop crucial for global food security,typically produces single seeds per spikelet.A team of researchers from the Institute of Genetics and Developmental Biology(IGDB)of the Chinese Academy of Sciences and the Sun Yat-sen University in Guangzhou recently identified a genetic mechanism that enables some varieties to develop double-grain spikelets,significantly boosting yields.By analyzing three genetic populations,scientists traced this trait to a 35.7-kilobase chromosomal inversion activating DG1-a gene that encodes a protein regulating floral meristem development.
基金This work is supported in part by the National Transgenic Science and Technology Program(2016ZX08010-002)National Natural Science Foundation of China(157101834)Agricultural Science and Technology Innovation Program of CAAS.
文摘The size and shape of rice grains influence their yield and commercial value.We investigated the role of OsDA1,a rice homolog of the Arabidopsis DA1 gene,in regulating grain size and shape.OsDA1 was highly expressed in young spikelets and glumes.Its overexpression led to enlarged seeds with increased width and decreased length/width ratio(LWR)and knocking out OsDA1 reduced grain width and increased grain length and LWR.A R310K point mutation in the DA1-like domain is a potential target for breeding for increased grain width and length.OsDA1 interacted with TCP gene-family proteins to regulate grain size and shape.Our findings deepen our understanding of the molecular mechanisms underlying grain size regulation and provide useful information for improving grain yield.
基金supported by the National Natural Science Foundation of China(Nos.12175231 and 11805131),Anhui Natural Science Foundation of China(No.2108085J05)Projects of International Cooperation and Exchanges NSFC(No.51111140389)the Collaborative Innovation Program of the Hefei Science Center,CAS(Nos.2021HSC-CIP020 and 2022HSCCIP009).
文摘Ferritic/martensitic(F/M)steel is widely used as a structural material in thermal and nuclear power plants.However,it is susceptible to intergranular damage,which is a critical issue,under service conditions.In this study,to improve the resistance to intergranular damage of F/M steel,a thermomechanical process(TMP)was employed to achieve a grain boundary engineering(GBE)microstructure in F/M steel P92.The TMP,including cold-rolling thickness reduction of 6%,9%,and 12%,followed by austenitization at 1323 K for 40 min and tempering at 1053 K for 45 min,was applied to the as-received(AR)P92 steel.The prior austenite grain(PAG)size,prior austenite grain boundary character distribution(GBCD),and connectivity of prior austenite grain boundaries(PAGBs)were investigated.Compared to the AR specimen,the PAG size did not change significantly.The fraction of coincident site lattice boundaries(CSLBs,3≤Σ≤29)and Σ3^(n) boundaries along PAGBs decreased with increasing reduction ratio because the recrystallization fraction increased with increasing reduction ratio.The PAGB connectivity of the 6%deformed specimen slightly deteriorated compared with that of the AR specimen.Moreover,potentiodynamic polarization studies revealed that the intergranular damage resistance of the studied steel could be improved by increasing the fraction of CSLBs along the PAGBs,indicating that the TMP,which involves low deformation,could enhance the intergranular damage resistance.
文摘The superplastic behavior and associated deformation mechanisms of a fine-grained Mg-10.1 Li-0.8Al-0.6Zn alloy(LAZ1011)with a grain size of 3.2μm,primarily composed of the BCCβphase and a small amount of the HCPαphase,were examined in a temperature range of 473 K to 623 K.The microstructural refinement of this alloy was achieved by employing high-ratio differential speed rolling.The best superplasticity was achieved at 523 K and at strain rates of 10^(-4)-5×10^(-4)s^(-1),where tensile elongations of 550±600%were obtained.During the heating and holding stage of the tensile samples prior to tensile loading,a significant increase in grain size was observed at temperatures above 573 K.Therefore,it was important to consider this effect when analyzing and understanding the superplastic deformation behavior and mechanisms.In the investigated strain rate range,the superplastic flow at low strain rates was governed by lattice diffusion-controlled grain boundary sliding,while at high strain rates,lattice diffusion-controlled dislocation climb creep was the rate-controlling deformation mechanism.It was concluded that solute drag creep is unlikely to occur.During the late stages of deformation at 523 K,it was observed that grain boundary sliding led to the agglomeration of theαphase,resulting in significant strain hardening.Deformation mechanism maps were constructed forβ-Mg-Li alloys in the form of 2D and 3D formats as a function of strain rate,stress,temperature,and grain size,using the constitutive equations for various deformation mechanisms derived based on the data of the current tests.
基金supported by grants from the National Natural Science Foundation of China(32325038)the Postdoctoral Fellowship Program of CPSF(GZB20230499)+1 种基金the Sichuan Science and Technology Program(24NSFSC4494)the Open Project Program(SKL-ZY202212)of State Key Laboratory of Crop Gene Exploration and Utilization in Southwest China.We thank the High-Performance Computing Platform of Sichuan Agricultural University for its support for the analysis of substitution segments in CSSL9-17.
文摘Grain size is a key factor influencing grain weight in rice.In this study,a chromosome segment substitution line(CSSL9-17)was identified,that exhibits a significant reduction in both grain size and weight compared to its donor parent 93-11.Further investigation identified two quantitative trait loci(QTL)on chromosome 11,designated qGW11a and qGW11b,which contribute to 1000-grain weight with an additive effect.LOC_Os11g05690,encoding the amino acid permease OsCAT8,is the target gene of qGW11a.Overexpression of OsCAT8 resulted in decreased grain weight,while OsCAT8 knockout mutants exhibited increased grain weight.The 287-bp located within the OsCAT8 promoter region of 93-11 negatively regulates its activity,which is subsequently correlated with an increase in grain size and weight.These results suggest that OsCAT8 functions as a negative regulator of grain size and grain weight in rice.
