Sharp phase interfaces and accurate temperature distributions are important criteria in the simulation of solid-liquid phase changes.The multi-relaxation-time lattice Boltzmann method(MRT-LBM)shows great numerical per...Sharp phase interfaces and accurate temperature distributions are important criteria in the simulation of solid-liquid phase changes.The multi-relaxation-time lattice Boltzmann method(MRT-LBM)shows great numerical performance during simulation;however,the value method of the relaxation parameters needs to be specified.Therefore,in this study,a random forest(RF)model is used to discriminate the importance of different relaxation parameters to the convergence,and a support vector machine(SVM)is used to explore the decision boundary of the convergent samples in each dimensional model.The results show that the convergence of the samples is consistent with the sign of the decision number,and two types of the numerical deviations appear,i.e.,the phase mushy zone and the non-physical heat transfer.The relaxation parameters chosen on the decision boundary can further suppress the numerical bias and improve numerical accuracy.展开更多
In this paper,a stochastic second-order two-scale(SSOTS)method is proposed for predicting the non-deterministic mechanical properties of composites with random interpenetrating phase.Firstly,based on random morphology...In this paper,a stochastic second-order two-scale(SSOTS)method is proposed for predicting the non-deterministic mechanical properties of composites with random interpenetrating phase.Firstly,based on random morphology description functions(RMDF),the randomness of the material properties of the constituents as well as the correlation among these random properties are fully characterized through the topologies of the constituents.Then,by virtue of multiscale asymptotic analysis,the random effective quantities such as stiffness parameters and strength parameters along with their numerical computation formulae are derived by a SSOTS strategy combined with the Monte-Carlo method.Finally,the SSOTS method developed in this paper shows an excellent computational accuracy,and therefore present an important advance towards computationally efficient multiscale modeling frameworks considering microstructure uncertainties.展开更多
In this work,a sponge-like polysulfonamide(PSA)/SiO_2 composite membrane is unprecedentedly prepared by the phase inversion method,and successfully demonstrated as a novel separator of lithium-ion batteries(LIBs).Comp...In this work,a sponge-like polysulfonamide(PSA)/SiO_2 composite membrane is unprecedentedly prepared by the phase inversion method,and successfully demonstrated as a novel separator of lithium-ion batteries(LIBs).Compared to the commercial polypropylene(PP) separator,the sponge-like PSA/SiO_2 composite possesses better physical and electrochemical properties,such as higher porosity,ionic conductivity,thermal stability and flame retarding ability.The LiCoO_2/Li half-cells using the sponge-like composite separator demonstrate superior rate capability and cyclability over those using the commercial PP separator.Moreover,the sponge-like composite separator can ensure the normal operation of LiCoO_2/Li half-cell at an extremely high temperature of 90 °C,while the commercial PP separator cannot.All these encouraging results suggest that this phase inversion based sponge-like PSA/SiO_2 composite separator is really a promising separator for high performance LIBs.展开更多
Tungsten nanoparticle-strengthened Cu composites were prepared from nanopowder synthesized by a sol–gel method and in-situ hydrogen reduction.The tungsten particles in the Cu matrix were well-dispersed with an averag...Tungsten nanoparticle-strengthened Cu composites were prepared from nanopowder synthesized by a sol–gel method and in-situ hydrogen reduction.The tungsten particles in the Cu matrix were well-dispersed with an average size of approximately 100–200 nm.The addition of nanosized W particles remarkably improves the mechanical properties,while the electrical conductivity did not substantially decrease.The Cu–W composite with 6 wt%W has the most comprehensive properties with an ultimate strength of 310 MPa,yield strength of 238 MPa,hardness of HV 108 and electrical conductivity of 90%IACS.The enhanced mechanical property and only a small loss of electrical conductivity demonstrate the potential of this new strategy to prepare W nanoparticle-strengthened Cu composites.展开更多
An in-situ TiCp/Al composite was prepared by a thermal explosion/quick pressure method （TE/QP）. The effect of Al content on the reaction temperature as well as the reaction rate has been studied. Phase constituents ...An in-situ TiCp/Al composite was prepared by a thermal explosion/quick pressure method （TE/QP）. The effect of Al content on the reaction temperature as well as the reaction rate has been studied. Phase constituents and the microstructure of the composites and the particle size of the reinforcement were analysed using X-ray diffraction （XRD） and scanning electron microscopy （SEM）. The results have shown that TiCp/Al composite with 40～70 vol. pct TiC particle reinforcement and high relative density can be directly obtained by TE/QP. TiC is the only reaction product when Al content in Al-Ti-C system is no more than 60 vol. pct, but Al3Ti phase will also form when Al content is more than 60 vol. pct. Increasing Al content prolongs the initial reaction time, reduces the highest reaction temperature and the reaction rate, and decreases the size of TiC particles. In addition, the microstructure of TiCp/Al composite and the structure of interface between TiCp and Al are studied using SEM and transmission electron microscopy （TEM）. The results show that the in-situ synthesized TiC particle has fcc cubic structure. The orientation between TiC particles and Al matrix can be described as （220）Al//（022）TiC and [112]Al//[011]TiC. Results of the mechanical property tests reveal that the ultimate strength （σ） and modulus （E） are 687 MPa and 142 GPa respectively when the Al content is 40 vol. pct. On contrary, 6 elongation increases by 3.2% with increasing Al content.展开更多
In order to improve the thermal properties of MMCs for electronic packaging,the concept of fabrication MMCs with particular interpenetrating phases(IPCs) was proposed. Based on the diffusion theory of reinforcement el...In order to improve the thermal properties of MMCs for electronic packaging,the concept of fabrication MMCs with particular interpenetrating phases(IPCs) was proposed. Based on the diffusion theory of reinforcement element in matrix alloys of some particular PMMCs,a novel fabrication method to produce IPCs was proposed. The Si/Al composites(65%Si,volume fraction) with interpenetrating phases were fabricated successfully by squeeze casting and hot press sintering technology. Microstructure observations indicate that the reinforcements Si are of three-dimensional continuous network and the composites are compact without obvious defects. The average linear thermal expansion coefficient(CTE) between 20 ℃ and 100 ℃ of the Si/Al IPCs is 8.27×10-6/K,and the thermal conductivity(TC) is 124.03 W/(m·K),and the composites can meet the demands of electronic packaging. ROM model and Turner model can be used to predict the CTEs of IPCs,and the experimental CTEs are between their theoretical and calculated values.展开更多
为了提高辣椒碱溶解度和生物利用度将其制备成微乳,经溶解度实验和伪三元相图确定微乳处方组成和表面活性剂与助表面活性剂的最佳质量比(Km);以粒径和载药量为考察指标,采用星点设计-响应面法优化辣椒碱微乳处方;并对最优处方制备的辣...为了提高辣椒碱溶解度和生物利用度将其制备成微乳,经溶解度实验和伪三元相图确定微乳处方组成和表面活性剂与助表面活性剂的最佳质量比(Km);以粒径和载药量为考察指标,采用星点设计-响应面法优化辣椒碱微乳处方;并对最优处方制备的辣椒碱微乳进行质量评价。辣椒碱微乳最优处方为辣椒碱5.12%,油酸乙酯5.82%,曲拉通X-100和无水乙醇(K_(m)=3∶1)28.54%,加纯化水至5.0 g;制得的微乳为O/W型澄清透明的均一液体,其形态为表面光滑的球形;CAP微乳粒径为16.5±0.17 nm,多分散指数为0.387±0.02,Zeta电位为-12.1±0.12 m V,粘度为33±1.73 m Pa·s;冻融稳定性和离心稳定性良好;红外光谱和差示扫描量热分析表明辣椒碱被包裹在微乳中。将辣椒碱制备成辣椒碱微乳,溶解度得以提高,解决了其水溶性低的问题,为辣椒碱的开发与应用提供一定的参考。展开更多
基金the National Natural Science Foundation of China(Nos.12172017 and 12202021)。
文摘Sharp phase interfaces and accurate temperature distributions are important criteria in the simulation of solid-liquid phase changes.The multi-relaxation-time lattice Boltzmann method(MRT-LBM)shows great numerical performance during simulation;however,the value method of the relaxation parameters needs to be specified.Therefore,in this study,a random forest(RF)model is used to discriminate the importance of different relaxation parameters to the convergence,and a support vector machine(SVM)is used to explore the decision boundary of the convergent samples in each dimensional model.The results show that the convergence of the samples is consistent with the sign of the decision number,and two types of the numerical deviations appear,i.e.,the phase mushy zone and the non-physical heat transfer.The relaxation parameters chosen on the decision boundary can further suppress the numerical bias and improve numerical accuracy.
基金partially supported by China Postdoctoral Science Foundation(2018M643573)National Natural Science Foundation of Shaanxi Province(2019JQ-048)+2 种基金National Natural Science Foundation of China(51739007,61971328,11301392 and 11961009)of ChinaShanghai Peak Discipline Program for Higher Education Institutions(ClassⅠ)–Civil EngineeringFundamental Research Funds for the Central Universities(No.22120180529)。
文摘In this paper,a stochastic second-order two-scale(SSOTS)method is proposed for predicting the non-deterministic mechanical properties of composites with random interpenetrating phase.Firstly,based on random morphology description functions(RMDF),the randomness of the material properties of the constituents as well as the correlation among these random properties are fully characterized through the topologies of the constituents.Then,by virtue of multiscale asymptotic analysis,the random effective quantities such as stiffness parameters and strength parameters along with their numerical computation formulae are derived by a SSOTS strategy combined with the Monte-Carlo method.Finally,the SSOTS method developed in this paper shows an excellent computational accuracy,and therefore present an important advance towards computationally efficient multiscale modeling frameworks considering microstructure uncertainties.
基金Supported by the funding from "135" Projects Fund of CAS-QIBEBT Director Innovation FoundationThink-Tank Mutual Fund of Qingdao Energy Storage Industry Scientific Research+3 种基金Qingdao Key Lab of Solar Energy Utilization and Energy Storage Technologythe Strategic Priority Research Program of the Chinese Academy of Sciences(XDA09010105)National Natural Science Foundation of China(51502319)Shandong Provincial Natural Science Foundation(ZR2016BQ18)
文摘In this work,a sponge-like polysulfonamide(PSA)/SiO_2 composite membrane is unprecedentedly prepared by the phase inversion method,and successfully demonstrated as a novel separator of lithium-ion batteries(LIBs).Compared to the commercial polypropylene(PP) separator,the sponge-like PSA/SiO_2 composite possesses better physical and electrochemical properties,such as higher porosity,ionic conductivity,thermal stability and flame retarding ability.The LiCoO_2/Li half-cells using the sponge-like composite separator demonstrate superior rate capability and cyclability over those using the commercial PP separator.Moreover,the sponge-like composite separator can ensure the normal operation of LiCoO_2/Li half-cell at an extremely high temperature of 90 °C,while the commercial PP separator cannot.All these encouraging results suggest that this phase inversion based sponge-like PSA/SiO_2 composite separator is really a promising separator for high performance LIBs.
基金supported by the Fundamental Research Funds for the Central Universities (No. FRF-TP-18-029A2)State Key Lab of Advanced Metals and Materials of China (No. 2019-Z10)
文摘Tungsten nanoparticle-strengthened Cu composites were prepared from nanopowder synthesized by a sol–gel method and in-situ hydrogen reduction.The tungsten particles in the Cu matrix were well-dispersed with an average size of approximately 100–200 nm.The addition of nanosized W particles remarkably improves the mechanical properties,while the electrical conductivity did not substantially decrease.The Cu–W composite with 6 wt%W has the most comprehensive properties with an ultimate strength of 310 MPa,yield strength of 238 MPa,hardness of HV 108 and electrical conductivity of 90%IACS.The enhanced mechanical property and only a small loss of electrical conductivity demonstrate the potential of this new strategy to prepare W nanoparticle-strengthened Cu composites.
文摘An in-situ TiCp/Al composite was prepared by a thermal explosion/quick pressure method （TE/QP）. The effect of Al content on the reaction temperature as well as the reaction rate has been studied. Phase constituents and the microstructure of the composites and the particle size of the reinforcement were analysed using X-ray diffraction （XRD） and scanning electron microscopy （SEM）. The results have shown that TiCp/Al composite with 40～70 vol. pct TiC particle reinforcement and high relative density can be directly obtained by TE/QP. TiC is the only reaction product when Al content in Al-Ti-C system is no more than 60 vol. pct, but Al3Ti phase will also form when Al content is more than 60 vol. pct. Increasing Al content prolongs the initial reaction time, reduces the highest reaction temperature and the reaction rate, and decreases the size of TiC particles. In addition, the microstructure of TiCp/Al composite and the structure of interface between TiCp and Al are studied using SEM and transmission electron microscopy （TEM）. The results show that the in-situ synthesized TiC particle has fcc cubic structure. The orientation between TiC particles and Al matrix can be described as （220）Al//（022）TiC and [112]Al//[011]TiC. Results of the mechanical property tests reveal that the ultimate strength （σ） and modulus （E） are 687 MPa and 142 GPa respectively when the Al content is 40 vol. pct. On contrary, 6 elongation increases by 3.2% with increasing Al content.
文摘In order to improve the thermal properties of MMCs for electronic packaging,the concept of fabrication MMCs with particular interpenetrating phases(IPCs) was proposed. Based on the diffusion theory of reinforcement element in matrix alloys of some particular PMMCs,a novel fabrication method to produce IPCs was proposed. The Si/Al composites(65%Si,volume fraction) with interpenetrating phases were fabricated successfully by squeeze casting and hot press sintering technology. Microstructure observations indicate that the reinforcements Si are of three-dimensional continuous network and the composites are compact without obvious defects. The average linear thermal expansion coefficient(CTE) between 20 ℃ and 100 ℃ of the Si/Al IPCs is 8.27×10-6/K,and the thermal conductivity(TC) is 124.03 W/(m·K),and the composites can meet the demands of electronic packaging. ROM model and Turner model can be used to predict the CTEs of IPCs,and the experimental CTEs are between their theoretical and calculated values.
文摘为了提高辣椒碱溶解度和生物利用度将其制备成微乳,经溶解度实验和伪三元相图确定微乳处方组成和表面活性剂与助表面活性剂的最佳质量比(Km);以粒径和载药量为考察指标,采用星点设计-响应面法优化辣椒碱微乳处方;并对最优处方制备的辣椒碱微乳进行质量评价。辣椒碱微乳最优处方为辣椒碱5.12%,油酸乙酯5.82%,曲拉通X-100和无水乙醇(K_(m)=3∶1)28.54%,加纯化水至5.0 g;制得的微乳为O/W型澄清透明的均一液体,其形态为表面光滑的球形;CAP微乳粒径为16.5±0.17 nm,多分散指数为0.387±0.02,Zeta电位为-12.1±0.12 m V,粘度为33±1.73 m Pa·s;冻融稳定性和离心稳定性良好;红外光谱和差示扫描量热分析表明辣椒碱被包裹在微乳中。将辣椒碱制备成辣椒碱微乳,溶解度得以提高,解决了其水溶性低的问题,为辣椒碱的开发与应用提供一定的参考。
