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grain size and surface micro-texture characteristics and their paleoenvironmental significance of Holocene sediment in southern margin of the Gurbantunggut Desert,China

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Journal of Arid Land 2024年第5期16卷 632-653页

作者： MA Yunqiang LI Zhizhong TAN Dianjia ZOU Xiaojun TAO Tonglian School of Geographical Sciences Fujian Normal UniversityFuzhou 350117China Key Laboratory for Humid Subtropical Eco-geographical Processes of the Ministry of Education Fujian Normal UniversityFuzhou 350117China Institute of Geography Fujian Normal UniversityFuzhou 350117China

The southern margin of the Gurbantunggut Desert,China,is characterized by alternating layers of aeolian and alluvial deposits.Investigating the characteristics of arenaceous sediment in this area is of significant importance for understanding the interactive processes of wind and water forces,as well as the provenance of sediment.However,there are relatively few investigations on the characteristics of such sediment at present.In this study,we researched three aeolian-alluvial interactive stratigraphic profiles and different types of surface sediment on the desert-oasis transitional zone of southern margin of the Gurbantunggut Desert.Based on the optically stimulated luminescence(OSL)dating of aeolian sand and analyses of quartz sand grain size and surface micro-texture,we explored the aeolian-alluvial environmental change at southern margin of the desert in Holocene,as well as the provenance of sediment.The results indicated that the grain size characteristics of different types of sediment in the stratigraphic profiles were similar to those of modern dune sand,interdune sand,muddy desert surface soil,and riverbed sand.Their frequency curves were unimodal or bimodal,and cumulative probability curves were two-segment or three-segment,mainly composed of suspension load and saltation load.The quartz sand in the sediment at southern margin of the desert had undergone alternating transformation of various exogenic forces,with short transportation distance and time,and sedimentary environment was relatively humid.In Holocene,southern margin of the desert primarily featured braided river deposits,and during intermittent period of river activity,there were also aeolian deposits such as sand sheet deposits,stabilized dune deposits,and mobile dune deposits.The provenance for Holocene alluvial deposits at southern margin of the desert remains relatively constant,with the debris of the Tianshan Mountains being the primary provenance.Aeolian sand is mainly near-source recharge,which is formed by in situ deposition of fluvial

关键词： aeolian-alluvial deposition grain size surface micro-texture sedimentary environment Holocene

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Effect of Texture on the grain-size-Dependent Functional Properties of NiTi Shape Memory Alloys and Texture Gradient Design:A Phase Field Study

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Acta Mechanica Solida Sinica 2024年第1期37卷 10-32页

作者： Bo Xu Beihai Huang Chong Wang Qingyuan Wang Failure Mechanics and Engineering Disaster Prevention Key Laboratory of Sichuan ProvinceSichuan UniversityChengdu 610065China Department of Mechanical Science and Engineering College of Architecture and EnvironmentSichuan UniversityChengdu 610065China Key Laboratory of Deep Underground Science and Engineering Ministry of EducationSichuan UniversityChengdu 610065China

Texture is inevitably introduced during the manufacturing of most NiTi shape memory alloys(SMAs),and the textured nanocrystalline NiTi has been extensively employed in engineering.However,the effect of texture,and the joint effect of grain size(GS)and texture on the functional properties of NiTi SMAs and the corresponding microscopic mechanisms have not been clearly understood yet.In this work,based on the phase field method,the effect of texture on the GS-dependent functional properties of NiTi SMAs,including super-elasticity(SE),one-way shape memory effect(OWSME),and stress-assisted two-way shape memory effect(SATWSME),is investigated,and the corresponding microscopic mechanisms are revealed.Moreover,the samples with discrete geometrical gradients and/or texture gradients are designed to achieve graded functional properties.The simulation results indicate that the dependence of functional properties on texture is due to the effect of crystallographic orientation on martensite transformation and reorientation,which can lead to different inelastic strains.In the designed samples with texture gradients,the stress–strain responses of sheets with various textures are different,allowing for the coordination of overall deformation of the sample by combining such sheets,with varying inelastic deformation degrees.Thus,the overall response of the sample differs from that without texture gradient,leading to the achievement of graded functional properties.The simulation results and new findings in this work contribute to a deeper understanding of the effects of texture,GS,and their interaction on the functional properties of SMAs,and provide valuable reference for the design and development of SMA-based devices with desired functional properties.

关键词： Phase field NiTi shape memory alloy Texture grain size Functional property Texture gradient

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Natural variation of an autophagy-family gene among rice subspecies affects grain size and weight

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The Crop Journal 2024年第1期12卷 121-132页

作者： Shiying Huang Peng Wang Caijing Li Qingwen Zhou Tao Huang Yicong Cai Qin Cheng Hui Wang Qi Zhong Zhihao Chen Liping Chen Haohua He Jianmin Bian Key Laboratory of Crop Physiology Ecology and Genetic BreedingMinistry of Education.Jiangxi Agricultural UniversityNanchang 330045JiangxiChina Weill Cornell Medical Immunology and Microbiology1300 York AvenueBox 62New YorkNY 10065USA

Elucidating the genetic basis of natural variation in grain size and weight among rice varieties can help breeders develop high-yielding varieties.We identified a novel gene,GW3a(grain Weight 3a)(LOC_Os03g27350),that affects rice grain size and weight.gw3a mutants showed higher total starch content and dry matter accumulation than the wild type(WT),Nipponbare,suggesting that GW3a negatively regulates grain size and weight.Moreover,our study found that GW3a interacted with OsATG8 by cleaving it,suggesting that GW3a may be involved in the assembly of autophagosomes and starch degradation in plants.The haplotype analysis of GW3a showed functional differences between indica and japonica rice.Taken together,we conclude that GW3a is expressed in the autophagosome pathway regulating starch metabolism in rice,affecting yield-related traits,such as grain size,grain weight and thousand grain weight(TGW).Our findings also shed new light on autophagy-mediated yield trait regulation,proposing a possible strategy for the genetic improvement of high-yield germplasm in rice.

关键词： grain size GW3a Autophagy Starch content

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Effect of Skeleton grain size on the Saturation of Gas Hydrate in Natural Sediments

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Journal of Ocean University of China 2024年第3期23卷 676-682页

作者： XU Zhenqiang LI Yang College of Marine Sciences Ocean University of ChinaQingdao 266100China China Petroleum&Chemical Corporation Beijing 100728China

Natural gas hydrate is prospected as a new and promising,highly clean energy resource that mainly occurs in perma-frost or at continental margins.Its formation is subject to many soil conditions,such as grain size,matrix materials,pore morphology,and permeability.In this study,we propose that grain size is the most decisive parameter that affects the saturation of gas hydrate in sediments based on data from Ocean Drilling Program Leg 164 and Mallik 5L-38,which represent marine sediments and terrestrial sediments,respectively.Our study reveals that high gas hydrate saturation generally occurs in coarse-grained sand,regardless of whether sediment formation is homogeneous or inhomogeneous,and the sorting of sediments may affect the hydrate saturation to a certain degree.Using grain size and sorting of sediments may be the most intuitive proxy method for a rough estimation of hydrate saturation.Further study is necessary to fully understand the relationship between hydrate morphology and sediment grain size,even though massive hydrates are typically found in fine clayey-rich sediments.

关键词： grain size saturation gas hydrates ODP Leg 164 Mallik 5L-38

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Rice AGL1 determines grain size and sterile lemma identity

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The Crop Journal 2024年第2期12卷 630-634页

作者： Haiping Yu An Wang Guangheng Zhang Guojun Dong Longbiao Guo Qian Qian Deyong Ren State Key Laboratory of Rice Biology and Breeding China National Rice Research InstituteHangzhou 310006ZhejiangChina Hainan Yazhou Bay Seed Laboratory Sanya 572024HainanChina National Nanfan Research Institute(Sanya) Chinese Academy of Agricultural SciencesSanya 572024HainanChina

The grass spikelet is a unique inflorescence structure that determines grain size.Although many genetic factors have been well characterized for grain size and glume development,the underlying molecular mechanisms in rice are far from established.Here,we isolated rice gene,AGL1 that controlled grain size and determines the fate of the sterile lemma.Loss of function of AGL1 produced larger grains and reduced the size of the sterile lemma.Larger grains in the agl1 mutant were caused by a larger number of cells that were longer and wider than in the wild type.The sterile lemma in the mutant spikelet was converted to a rudimentary glume-like organ.Our findings showed that the AGL1(also named LAX1)protein positively regulated G1 expression,and negatively regulated NSG1 expression,thereby affecting the fate of the sterile lemma.Taken together,our results revealed that AGL1 played a key role in negative regulation of grain size by controlling cell proliferation and expansion,and supported the opinion that rudimentary glume and sterile lemma in rice are homologous organs.

关键词： Abnormal grain and sterile lemma 1 Oryza sativa grain size Rudimentary glume

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Genetic analysis and fine mapping of a grain size QTL in the smallgrain sterile rice line Zhuo201S

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Journal of Integrative Agriculture 2024年第7期23卷 2155-2163页

作者： Bin Lei Jiale Shao Feng Zhang Jian Wang Yunhua Xiao Zhijun Cheng Wenbang Tang Jianmin Wan College of Agronomy Hunan Agricultural UniversityChangsha 410128China National Key Facility for Crop Gene Resources and Genetic Improvement/Institute of Crop Sciences Chinese Academy of Agricultural SciencesBeijing 100081China State Key Laboratory for Crop Genetics and Germplasm Enhancement/Jiangsu Plant Gene Engineering Research Center Nanjing Agricultural UniversityNanjing 210095China State Key Laboratory of Hybrid Rice Hunan Hybrid Rice Research CenterChangsha 410125China

The development and application of the small-grain rice sterile line Zhuo201S(Z201S)has demonstrated its potential for mechanized hybrid rice seed production,leading to significant cost reductions.However,the molecular mechanism responsible for the small-grain size characteristic of Z201S remains unclear.In this study,we conducted a genetic analysis using near-isogenic lines constructed from Z210S,a small-grain rice sterile line,and R2115,a normal-grain variety.The results revealed that the small-grain trait in Z201S is governed by a single partially dominant gene which also enhances grain number.Through mapping,we localized the causal gene to the short arm of chromosome 2,within a 113 kb physical region delimited by the molecular markers S2-4-1 and LB63.Transgenic analysis and gene expression assays indicated LOC_Os02g14760 as the most likely candidate gene,suggesting that the small-grain size trait of Z201S is controlled by a novel locus that has not been previously identified.

关键词： rice grain size map-based cloning

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Effect of grain size on gas bubble evolution in nuclear fuel:Phase-field investigations

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Chinese Physics B 2024年第1期33卷 563-572页

作者：孙丹杨青峰赵家珺高士鑫辛勇周毅尹春雨陈平赵纪军王园园 Science and Technology on Reactor System Design Technology Laboratory Nuclear Power Institute of ChinaChengdu 610213China Key Laboratory of Materials Modification by Laser Ionand Electron BeamsDalian University of TechnologyDalian 116024China

Numerous irradiation-induced gas bubbles are created in the nuclear fuel during irradiation, leading to the change of microstructure and the degradation of mechanical and thermal properties. The grain size of fuel is one of the important factors affecting bubble evolution. In current study, we first predict the thermodynamic behaviors of point defects as well as the interplay between vacancy and gas atom in both UO_(2) and U_(3)Si_(2) according to ab initio approach. Then, we establish the irradiation-induced bubble phase-field model to investigate the formation and evolution of intra-and inter-granular gas bubbles. The effects of fission rate and temperature on the evolutions of bubble morphologies in UO_(2) and U_(3)Si_(2) have been revealed. Especially, a comparison of porosities under different grain sizes is examined and analyzed. To understand the thermal conductivity as functions of grain size and porosity, the heat transfer capability of U_(3)Si_(2) is evaluated.

关键词： grain size point defects fission gas bubble

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grain size dependence of annealing strengthening of an extruded Mg-Gd-Zn alloy subjected to pre-compression deformation

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Journal of Magnesium and Alloys 2022年第12期10卷 3576-3588页

作者： Qinghang Wang Siyuan Chen Bin Jiang Zhaoyang Jin Lingyu Zhao Junjie He Dingfei Zhang Guangsheng Huang Fusheng Pan School of Mechanical Engineering Yangzhou UniversityYangzhou225127China National Engineering Research Center for Magnesium Alloys Chongqing UniversityChongqing400044China School of Materials and Energy Yunnan UniversityKunming650599China

In this work, pre-strain annealing strengthening(PSAS) effect was investigated in an extruded Mg-1.0Gd-1.5 Zn(wt.%) alloy with respect to different grain sizes. The evolution of microstructures was provided by scanning electron microscopy(SEM), electron backscattered diffraction(EBSD), transmission electron microscopy(TEM) and high-angle annular dark-field scanning transmission electron microscopy(HAADF-STEM) under the initial state, pre-compression, intermediate annealing and re-compression conditions. The obtained results showed a grain size-dependent PSAS effect in the alloy. The sample with larger grain sizes corresponded to a higher strengthening effect, which mainly resulted from a more remarkable hindrance for the growth of existing twins and a larger proportion of activation for the nucleation of new twins. This was closely associated with the increase of back stress and friction stress for twin boundary motion impeded by the larger restraint of dislocations, the higher stress field surrounding solutes and the more Zn segregation. In addition to twinning behavior, Guinier Preston(G.P.) zones on basaldislocations were found after intermediate annealing and provided an extra strengthening by inhibiting the motions of gilding pre-existing dislocations and newly formed ones, but it was independent on the grain size.

关键词： Mg-Gd-Zn alloy grain size Pre-compression Annealing strengthening Twinning

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grain-size effect on dislocation source-limited hardening and ductilization in bulk pure Ni

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Journal of Materials Science & Technology 2023年第23期154卷 9-21页

作者： Kai Hu Jun Yi Bo Huang Gang Wang Institute of Materials School of Materials Science and Engineering Shanghai University Shanghai 200444 China

Dislocation source-limited hardening and ductilization is an effective strategy to obtain superior strength-ductility synergy in some engineering structural metals. Recent works demonstrated that the synergy could be enhanced by grain-size reduction. However, the mechanism of grain-size dependence is still a mystery. In this work, bulk pure Ni produced by electrodeposition and subsequent annealing, with grain sizes ranging from ∼20 nm to ∼20 µm, were methodically investigated to unravel the mechanism of the grain-size effect on dislocation source-limited hardening and ductilization. The high-density nano-twinning in the as-electrodeposited nanograined specimens exhibited better thermodynamic stability than the peers with random high-angle grain boundaries, leading to fine recrystallized grains with low-density dislocations. The low dislocation density enabled extra hardening beyond grain boundary strengthening via yield-point behavior with grain sizes ranging from ∼110 nm to ∼10 µm and extra ductilization over ∼500 nm. This work demonstrated that the prerequisite for dislocation source-limited hardening was that the dislocation density of the specimen should be lower than the size-dependent critical value of ((1.1 × 107 /d ) m^(–2), d is the grain size in unit of the meter) where a transition from forest-dominated hardening to dislocation source-limited hardening could occur. On the other hand, dislocation source-limited ductilization only worked when the grain size was comparable to/larger than the theoretical dislocation mean slip distance. Dislocation source-limited ductilization resulted from more room in grains for accumulation of dislocations and deformation nano-stacking faults enabling the higher work hardening rate. This work offered an altogether new avenue to obtain stronger and more ductile metallic materials through utilizing grain-size dependent dislocation source-limited hardening and ductilization.

关键词： Dislocation source-limited hardening Dislocation source-limited ductilization grain size Yield point Hall-Petch slope

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Molecular bases of rice grain size and quality for optimized productivity

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Science Bulletin 2023年第3期68卷 314-350,M0004页

作者： Deyong Ren Chaoqing Ding Qian Qian State Key Laboratory of Rice Biology China National Rice Research InstituteHangzhou 310006China

The accomplishment of further optimization of crop productivity in grain yield and quality is a great challenge.grain size is one of the crucial determinants of rice yield and quality;all of these traits are typical quantitative traits controlled by multiple genes.Research advances have revealed several molecular and developmental pathways that govern these traits of agronomical importance.This review provides a comprehensive summary of these pathways,including those mediated by G-protein,the ubiquitin–proteasome system,mitogen-activated protein kinase,phytohormone,transcriptional regulators,and storage product biosynthesis and accumulation.We also generalize the excellent precedents for rice variety improvement of grain size and quality,which utilize newly developed gene editing and conventional gene pyramiding capabilities.In addition,we discuss the rational and accurate breeding strategies,with the aim of better applying molecular design to breed high-yield and superior-quality varieties.

关键词： Rice grain size grain quality Genetic control Molecular networks Variety improvement

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