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6篇 您的检索式:作者名="DAI PinQiang"
    题名 作者 年代 出处 被引量
1Theoretical analysis of reactive solid-liquid interfacial energies显示文摘The characterization of reactive solid-liquid interfacial energies and solid surface energies is a pressing problem in materials science and surface science. Based on the concept that unbalanced forces doing work, a mathematical formulation between surface energies and interfacial energies for reactive wetting is presented. The resulting formalism has significant generality in which the equilibrium Young's equation for solid-liquid interfacial energies is just a special case. It is shown that a solid-liquid interfacial energy at non-equilibrium is always higher than that at equilibrium, and that the transformation of reactive interfaces to equilib-rium interfaces is an inevitable, spontaneous process. The numerical range of solid-liquid interfacial energies γsl for a limited, solid-liquid interfacial wetting system was calculated to be 0 ≤γsl ≤γsg. The calculation methods for reactive solid-liquid interfacial energies and solid surface energies are presented. They are significant for composite materials and weld, powder sinter, package of electronic devices, and other surface and interfacial issues in metallurgy.ZHU DingYi LIAO XuanMao DAI PinQiang 2012Chinese Science Bulletin2012,57,34:4
2Parti- cle Swarm Optimization Based Algorithm for Ship Vertical Passage Layout Optimization显示文摘Chen Wenzhe Dai Pinqiang Chen Yonglu 2012Ad vanced Materials Research2012,,:1
3Three-dimensional structure of an observed cyclonic mesoscale eddy in the Northwest Pacific and its assimilation experiment显示文摘Mesoscale eddies play an important role in modulating the ocean circulation.Many previous studies on the threedimensional structure of mesoscale eddies were mainly based on composite analysis,and there are few targeted observations for individual eddies.A cyclonic eddy surveyed during an oceanographic cruise in the Northwest Pacific Ocean is investigated in this study.The three-dimensional structure of this cyclonic eddy is revealed by observations and simulated by the four-dimensional variational data assimilation(4 DVAR)system combined with the Regional Ocean Modeling System.The observation and assimilation results together present the characteristics of the cyclonic eddy.The cold eddy has an obvious dual-core structure of temperature anomaly.One core is at 50–150 m and another is at 300–550 m,which both have the average temperature anomaly of approximately-3.5℃.The salinity anomaly core is between 250 m and 500 m,which is approximately-0.3.The horizontal velocity structure is axis-asymmetric and it is enhanced on the eastern side of the cold eddy.In the assimilation experiment,sea level anomaly,sea surface temperature,and in situ measurements are assimilated into the system,and the results of assimilation are close to the observations.Based on the high-resolution assimilation output results,the study also diagnoses the vertical velocity in the mesoscale eddy,which reaches the maximum of approximately 10 m/d.The larger vertical velocity is found to be distributed in the range of 0.5 to 1 time of the normalized radius of the eddy.The validation of the simulation result shows that the 4 DVAR method is effective to reconstruct the three-dimensional structure of mesoscale eddy and the research is an application to study the mesoscale eddy in the Northwest Pacific by combining observation and assimilation methods.Jun Dai Huizan Wang Weimin Zhang Pinqiang Wang Tengling Luo 2021Acta Oceanologica Sinica2021,40,5:1
4Demonstration of the refined three-dimensional structure of mesoscale eddies and computational error estimates via Lagrangian analysis显示文摘In previous studies,Lagrangian analyses were used to assess large-scale ocean circulation,and the Lagrangian coherent structure could also reveal the evolution of the two-dimensional structure of the mesoscale eddies.However,few studies have demonstrated the three-dimensional structure of the mesoscale eddies via Lagrangian analysis.Compared with previous studies,which investigated the eddy structure via a Eulerian view,we used a Lagrangian view to provide a different perspective to study the eddy structure.An idealized cyclonic mesoscale eddy is built up over a seamount,and it presents downwelling inside the eddy and upwelling alongside the eddy formed within a closed circulation system.This structure is difficult to display via a Eulerian analysis.However,the trajectories of particles can well demonstrate the full cycle:the fluid sank and rotated inside the eddies,converged to the upwelling zone of the bottom layer and returned to the surface through upwelling.We also applied a Lagrangian analysis to a realistic simulation.As a significant phenomenon in the South China Sea,the dipole structure of the anticyclonic eddy(AE)/cyclonic eddy(CE)pair off of central Vietnam has been well studied but mainly at the sea surface.With a Lagrangian analysis,we illustrate the three-dimensional structure of the eddy pair:the fluid sank(rose)and rotated inside the AE(CE).More importantly,the trajectories of the particles suggested that there was no fluid exchange between the two eddies since the strong boundary jet separates them from each other.All the conclusions above have been verified and are supported by the computational error estimate.With a selected time step and integral period,the computational errors always present small values,although they increase with strong divergent and vertical diffusive flow.Heqing Yin Haijin Dai Weimin Zhang Xueyan Zhang Pinqiang Wang 2020Acta Oceanologica Sinica2020,39,7:0
5Synthesis,formation mechanism,and intrinsic physical properties of several As/P-containing MAX phases显示文摘321 phases are an atypical series of MAX phases,in which A=As/P,with superior elastic properties,fea-turing in the MA-triangular-prism bilayers in the crystal structure.Until now,besides Nb 3 As 2 C,the pure phases of the other 321 compounds have not been realized,hampering the study of their intrinsic prop-erties.Here,molten-salt sintering(MSS)and solid-state synthesis(SSS)were applied to synthesize As/P-containing 321 phases and 211 phases.Analyzing the phase composition of the end-product via multiple-phase Rietveld refinement,we found that MSS can effectively improve the purity of P-containing MAX phases,with the phase content up to 99%in Nb_(3)P_(2)C and 75.4(5)%in Nb 2 PC.In contrast,MSS performed poorly on As-containing MAX phases,only 8.9(4)%for Nb 3 As 2 C and 64(2)%for Nb 2 AsC,as opposed to the pure phases obtained by SSS.The experimental analyses combined with first-principles calculations reveal that the dominant formation route of Nb_(3)P_(2)C is through NbP+Nb+C→Nb_(3)P_(2)C.Moreover,we found that the benefits of MSS on P-containing MAX phases are on the facilitation of three consid-ered chemical reaction routes,especially on Nb 2 PC+NbP→Nb_(3)P_(2)C.Furthermore,the intrinsic physical properties and Fermi surface topology of two 321 phases consisting of electron,hole,and open orbits are revealed theoretically and experimentally,in which the electron carriers are dominant in electrical trans-port.The feasible synthesis methods and the formation mechanism are instructive to obtain high-purity As/P-containing MAX phases and explore new MAX phases.Meanwhile,the intrinsic physical properties will give great support for future applications on 321 phases.Hongxiang Chen Sheng Li Jun Deng Zhilong Zhang Jianeng Huang Fa Chang Li Huang Shixuan Du Pinqiang Dai 2023Journal of Materials Science & Technology2023,,2:0
6Observation of low thermal expansion behavior and weak thermal anisotropy in M_(3)A_(2)C phases显示文摘M_(3)A_(2)X phases,named 321 phases,are an atypical series of MAX phases featuring in the MA-triangular-prism bilayers,with the A=As/P,exhibiting excellent elastic properties.This work systematically studies the thermal expansion properties of 321 phases.We found their average linear thermal expansion coefficients(TECs),α_(L)=5-6μK^(–1),are the lowest among the reported values of MAX phases.The lowest average TEC was found in Nb_(3)As_(2)C(αa=4.46(4)μK^(–1),αc=5.09(4)μK–1,αL=5.09(4)μK–1).The average TEC and anisotropy factor(αc/αa)of Nb_(3)As_(2)C and Nb_(3)P_(2)C were lower than the ones of the corresponding 211 phases.The best isotropy performance was found in Nb_(3)P_(2)C (αc/αa=1.11).Moreover,our first-principles calculations demonstrate that the weaker chemical bonding between Nb-As/P than Nb-C induces thermal expansion in M_(3)A_(2)X phases.Furthermore,a relatively weaker anharmonic effect in 321 phases than in the 211 phases was revealed by the as-calculated average Grüneisen parameters,which account for the lower TECs in 321 phases.The low TECs and enhanced thermal isotropy make 321 phases outstanding among MAX phases,which could be sound candidates for varying-temperature structural-functional components.Hongxiang Chen Zhilong Zhang Jun Deng Zhijie Lin Chunfu Hong Shixuan Du Pinqiang Dai 2023Journal of Materials Science & Technology2023,,23:0
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