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Phase field crystal simulation of grain boundary movement and dislocation reaction

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Frontiers of Materials Science 2014年第2期8卷 176-184页

作者： ying-jun gao Qian-Qian DENG Si-Long QUAN Wen-Quan ZHOU Chuang-gao HUANG College of Physical Science and Engineering Guangxi University Nanning 530004 China Guangxi Key Laboratory for Non-Ferrous Metal and Featured Materials Nanning 530004 China

The phase field crystal （PFC） model is used to simulate the premelting dislocation movement of the symmetric tilt grain boundary （STGB） under strain action when the system temperature is at far from the melting point and close to the melting point, respectively. The results show a local premelting occurs surrounding the dislocations as the premelting temperature is approached to from below temperature. The premelting dislocations of the STGB can glide under strain action, and the premelting region is a companion for dislocation gliding. The process of STGB decay is very similar at the two high temperature conditions. As premelting presents, it diminishes the gliding resistance for the dislocations and leads to a faster movement of dislocations, and also brings about more energy reduction of the system during the decay process of STGB. In spite of applying strain to these premelting samples in whole decay processes of STGB, the premelting dislocation region does not obviously develop and extend. This indicates that the external strain action does not promote the premelting at the high temperature, and cannot induce more premelting dislocation, which can be owed to the premelting phase around the dislocation exhibit fluid-like properties and to the premelting dislocation easily gliding and relaxing the strain energy; this is in agreement with the results of experiments and molecular dynamics.

关键词： phase field crystal (PFC) model grain boundary (GB) premeltingdislocation strain

Modes of grain growth and mechanism of dislocation reaction under applied biaxial strain:Atomistic and continuum modeling

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Journal of Materials Science & Technology 2020年第14期47卷 236-250页

作者： ying-jun gao Qian-Qian Deng Zhe-yuan Liu Zong-Ji Huang Yi-Xuan Li Zhi-Rong Luo Guangxi Advanced Key Laboratory of Novel Energy Materials Guangxi Key Laboratory for the Relativistic AstrophysicsSchool of Physics Science and EngineeringGuangxi UniversityNanning530004China Institute of Physics Science and Engineering Technology Yulin Normal UniversityYulin537000China

The phase field crystal method and Continuum Modeling are applied to study the cooperative dislocation motion of the grain boundary(GB)migration,the manner of the nucleation of the grain and of the grain growth in two dimensions(2 D)under the deviatoric deformation at high *** types of the nucleation modes of new finding are observed by the phase field crystal simulation:The first mode of the nucleation is generated by the GB splitting into two sub-GBs;the second mode is of the reaction of the sub-GB dislocations,such as,the generation and annihilation of a pair of partial Frank sessile dislocation in 2 *** process can be considered as the nucleation of dynamic recrystallization;the third mode is caused by two oncoming rows of the dislocations of these sub-GBs,crossing and passing each other to form new gap which is the nucleation place of the new deformed *** research is shown that due to the nucleation of different modes the mechanism of the grain growth by means of the sub-GB migration is different,and therefore,the grain growth rates are also *** the deviatoric deformation of the applied biaxial strain,the grain growth is faster than that of the grain growth without external applied *** is observed that the cooperative dislocation motion of the GB migration under the deviatoric deformation accompanies with local plastic flow and the state of the stress of the system changes *** the system is in the process of recrystallized grain growth,the system energy is in an unstable state due to the release of the strain energy to cause that the reverse movement of the plastic flow *** area growth of the deformed grain is approximately proportional to the strain square and also to the time *** rule of the time square of the deformed grain growth can also be deduced by establishing the continuum dynamic equation of the biaxial strain-driven migration of the *** copper metal is taken as an example of the calcu

关键词： Grain boundary splitting Grain growth Dislocation reaction Atomistic simulation Continuum modeling

The Growth Analysis in the Kernel Filling Process of K-Type Hybrid 901 and Its Parent Wheat

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Agricultural Sciences in China 2005年第12期4卷 903-908页

作者： GONG Yue-hua LIU ying-zhou gao jun-feng College of Life Science Northwest A ＆ F University Yangling 712100 PR.China

Using Matlab software, the grain filling process of hybrid wheat 901 and its parents was fitted by Richards equation W = A/（1 ＋ Be^-kt in order to study the characteristics of grain filling of the hybrid. The active grain growth period of the hybrid was 6 d longer than that of Shaan 229, and its final grain weight （43.7 g/1 000 grains） was higher than that of Shaan229 （36.3 g/1 000 grains）. N values of 901 and R205 were both less than 1, and their grain growth was faster in the early filling stage, while slower in the middle-late stage. N value of Shaan 229 was 〉1~ and its growth was slower in the early stage and faster in the middle stage. The period of early stage of 901 was shorter and of middle-late stage was longer. The situation of Shaan 229 was totally reversed. For parents, the father plant R205 was similar to hybrid wheat 901, whereas its mother plant K3314A similar to Shaan 229. It has been found that Richards equation was more suitable for fitting the grain filling process of wheat than Logistic equation.

关键词： Hybrid wheat 901 Parent plants Grain-filling

Highly Efficient and Recyclable Catalyst HBF_4·SiO_2 Catalyzed Synthesis of β-Enamino Compounds Under Solvent-free Conditions

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Chemical Research in Chinese Universities 2011年第5期27卷 792-794页

作者： gao Han JIA Xu-dong DUAN Hai-feng LIN ying-jie gao jun-gang LIANG Da-peng WU Mao-cheng Department of Organic Chemistry College of Chemistry dilin University Changchun 130012 l~ R. China

Fluoroboric acid adsorbed on silica-gel（HBF4·SiO2） has been found to be an extremely efficient and recyclable catalyst for the preparation of β-enaminones and β-enamino esters under solvent-free conditions.

关键词： β-Enaminone β-Enamino ester HBF4·SiO2 Solvent-free condition

A New Biflavone from Selaginella pulvinata Maxim

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有机化学 2003年第Z1期23卷 395-396页

作者： XU Kang-Ping XU Zhi DENG Yin-Hua LI Fu-Shuang ZHOU ying-jun HU gao-Yun TAN Gui-Shan Department of Medicinal Chemistry School of Pharmaceutical Sciences Central South University Changsha 410078 Department of Medicinal Chemistry School of Pharmaceutical Sciences Central South University Changsha 410078 Department of Medicinal Chemistry School of Pharmaceutical Sciences Central South University Changsha 410078 Department of Medicinal Chemistry School of Pharmaceutical Sciences Central South University Changsha 410078 Department of Medicinal Chemistry School of Pharmaceutical Sciences Central South University Changsha 410078 Department of Medicinal Chemistry School of Pharmaceutical Sciences Central South University Changsha 410078 Department of Medicinal Chemistry School of Pharmaceutical Sciences Central South University Changsha 410078

　　Selaginella pulvinata Maxim. distributes all over the country of China and is used for the treatment for haemor rhage. [1] We studied on the chemical constituents of S. pulvinata in order to find the active compounds. Dried stems and leaves of S. pulvinata (6.5 kg) were extracted with 70% ethanol twice. The extract was evaporated under vacuum and than suspended in water, extracted with petroleum and EtOAc sequentially. The EtOAc extract was chromatographed on silica gel, eluted with CHCl3-MeOH. As a result, a novel biflavone, named pulvinatabiflavone, was obtained from fractions 75 ～ 78. Its structure was determined on the basis of spectroscopic analysis as 5,5″, 4′″ trihydroxy-7,7″-dimethoxy-[4′-O-6″]-biflavone (compound 1).……

关键词： spectroscopic analysis chemical constituents silica gel in order

Sharp Isolated Toughness Bound for Fractional(k,m)-Deleted Graphs

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Acta Mathematicae Applicatae Sinica 2025年第1期41卷 252-269页

作者： Wei gao Wei-fan WANG Yao-jun CHEN School of Mathematics Hohai UniversityNanjing 210098China Department of Mathematics Zhejiang Normal UniversityJinhua 321004China Department of Mathematics Nanjing UniversityNanjing 210093China

A graph G is a fractional(k,m)-deleted graph if removing any m edges from G,the resulting subgraph still admits a fractional *** k≥2 and m≥1 be ***[2m/k]^(*)=[2m/k]if 2m/k is not an integer,and[2m/k]^(*)=[2m/k]-1 if 2m/k is an *** this paper,we prove that G is a fractional(k,m)-deleted graph if δ(G)≥k+m and isolated toughness meets I(G)>{3-1/m,if k=2 and m≥3,k+[2m/k]^(*)m+1-[2m/k]^(*);***,we show that the isolated toughness bound is tight.

关键词： graph isolated toughness fractional k-factor fractional(k,m)-deleted graph

Meteorological effects on sources and future projection of nitrogen deposition to lakes in China

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Journal of Environmental Sciences 2025年第5期151卷 100-112页

作者： Cheng Shi Hao Guo Xue Qiao Jingsi gao ying Chen Hongliang Zhang Department of Biological and Ecological Engineering Oregon State UniversityCorvallisOR 97331USA State Key Laboratory of Organic Geochemistry Guangzhou Institute of GeochemistryChinese Academy of SciencesGuangzhou 510640China Institute of New Energy and Low-carbon Technology Sichuan UniversityChengdu 610065China Engineering Technology Development Center of Urban Water Recycling Shenzhen PolytechnicShenzhen 518055China Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention Department of Environmental Science and EngineeringFudan UniversityShanghai 200438China IRDR ICoE on Risk Interconnectivity and Governance on Weather/Climate Extremes Impact and Public Health Fudan UniversityShanghai 200438China

Lake ecosystems are extremely sensitive to nitrogen growth,which leads to water quality degradation and ecosystem health *** depositions,as one of the main sources of nitrogen in water,are expected to change under future climate change ***,it remains not clear how nitrogen deposition to lakes respond to future meteorological *** this study,a source-oriented version of Community Multiscale Air Quality(CMAQ)Model was used to estimate nitrogen deposition to 263 lakes in 2013 and under three RCP scenarios(4.5,6.0 and 8.5)in *** total deposition of 58.2 Gg nitrogen was predicted for all lakes,with 23.3 Gg N by wet deposition and 34.9 Gg N by dry *** and ammonium in aerosol phase are the major forms of wet deposition,while NH3 and HNO_(3)in gas phase are the major forms of dry *** emissions contribute to 57%of wet deposition and 44%of dry *** future meteorological conditions,wet deposition is predicted to increase by 5.5%to 16.4%,while dry deposition would decrease by 0.3%to 13.0%.Changes in wind speed,temperature,relative humidity(RH),and precipitation rates are correlated with dry and wet deposition *** predicted changes in deposition to lakes driven by meteorological changes can lead to significant changes in aquatic chemistry and ecosystem *** from future emission scenarios,different climate scenarios should be considered in future ecosystem health evaluation in response to nitrogen deposition.

关键词： Deposition Nitrogen Lakes CMAQ Meteorological variations

Adsorption of typical NDMA precursors by superfine powdered activated carbon:Critical role of particle size reduction

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Journal of Environmental Sciences 2025年第1期147卷 101-113页

作者： ying Wang Zhichen Zhang Zhihang Yin jun Wang Xiaojian Zhang Chao Chen State Key Joint Laboratory of Environmental Simulation and Pollution Control School of EnvironmentTsinghua UniversityBeijing 100084China Research Institute for Environmental Innovation(Suzhou) TsinghuaSuzhou 215163China

Control of N-nitrosodimethylamine(NDMA)in drinking water could be achieved by removing its precursors as one practical ***,superfine powdered activated carbons with a diameter of about 1μm(SPACs)were successfully prepared by grinding powdered activated carbon(PAC,D50=24.3μm)and applied to remove model NDMA precursors,***(RAN)and nizatidine(NIZ).Results fromgrain diameter experiments demonstrated that the absorption velocity increased dramatically with decreasing particle size,and the maximum increase in k2 was 26.8-folds for RAN and 33.4-folds for ***,kinetic experiments explained that rapid absorption could be attributed to the acceleration of intraparticle diffusion due to the shortening of the diffusion ***,performance comparison experiments suggested that the removal of RAN and NIZ(C_(0)=0.5 mg/L)could reach 61.3%and 60%,respectively,within 5 min,when the dosage of SAPC-1.1(D_(50)=1.1μm)was merely 5 mg/L,while PAC-24.3 could only eliminate 17.5%and 18.6%.The adsorption isotherm was well defined by Langmuir isotherm model,indicating that the adsorption of RAN/NIZ was a monolayer coverage *** adsorption of RAN or NIZ by SAPC-1.1 and PAC-24.3 was strongly pH dependent,and high adsorption capacity could be observed under the condition of pH>pk_(a)+*** coexistence of humic acid(HA)had no significant effect on the adsorption performance because RAN/NIZ may be coupled with HA and removed *** coexistence of anions had little effect on the adsorption *** study is expected to provide an alternative strategy for drinking water safety triggered by NDMA.

关键词： Adsorption NDMA Kinetics Superfine powdered activated carbon Intraparticle diffusion Drinking water

Structural and microwave absorption properties of CoFe_(2)O_(4)/residual carbon composites

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International Journal of Minerals,Metallurgy and Materials 2025年第1期32卷 221-232页

作者： Yuanchun Zhang Shengtao gao Xingzhao Zhang Dacheng Ma Chuanlei Zhu jun He Joint National-Local Engineering Research Centre for Safe and Precise Coal Mining Anhui University of Science and TechnologyHuainan 232001China School of Chemical and Blasting Engineering Anhui University of Science and TechnologyHuainan 232001China

Electromagnetic interference,which necessitates the rapid advancement of substances with exceptional capabilities for bsorbing electromagnetic waves,is of urgent concern in contemporary *** this work,CoFe_(2)O_(4)/residual carbon from coal gasification fine slag(CFO/RC)composites were created using a novel hydrothermal *** mechanisms for microwave absorption,including conductive loss,natural resonance,interfacial dipole polarization,and magnetic flux loss,are involved in these ***,compared with pure residual carbon materials,this composite offers superior capabilities in microwave *** 7.76GHz,the CFO/RC-2 composite achieves an impressive minimum reflection loss(RL_(min))of-43.99 dB with a thickness of 2.44 ***,CFO/RC-3 demonstrates an effective absorption bandwidth(EAB)of up to 4.16 GHz,accompanied by a thickness of *** study revealed the remarkable capability of the composite to diminish electromagnetic waves,providing a new generation method for microwave absorbing materials of superior quality.

关键词： coal gasification slag residual carbon hydrothermal method microwave absorption CoFe_(2)O_(4)