C ^＋ ion beam-assisted deposition was utilized to prepare deposit diamond-like carbon （ DLC ） film. With the help of a series of experiments such as Raman spectroscopy, FT-IR spectroscopy, AFM and nanoindentation ,...C ^＋ ion beam-assisted deposition was utilized to prepare deposit diamond-like carbon （ DLC ） film. With the help of a series of experiments such as Raman spectroscopy, FT-IR spectroscopy, AFM and nanoindentation , the DLC film has been recognized as hydrogenated DLC film and its tribologicul properties have been evaluated. The bull-on-disc testing results show that the hardness and the tribologicul properties of the DLC film produced by C^ ＋ ion beam- assisted deposition are improved significantly. DLC film produced by C ^＋ ion beam- assisted deposition is positive to have a prosperous tribologicul application in the near future.展开更多
Bimetallic clusters have aroused tremendous interest because the property changes like structure,size,and composition have occurred.Herein,a structural search of the global minimum for anionic LiMg_(n)^(-)(n=2-11) clu...Bimetallic clusters have aroused tremendous interest because the property changes like structure,size,and composition have occurred.Herein,a structural search of the global minimum for anionic LiMg_(n)^(-)(n=2-11) clusters is performed using an efficient crystal structure analysis by particle swarm optimization(CALYPSO) structural searching program with subsequent density functional theory(DFT) calculations.A great variety of low energetic isomers are converged,and the most stable ones are confirmed by comparing their total energy of each size.It is found that the LiMg_(n)^(-)clusters are structurally consistent with corresponding Mg clusters anions except for LiMg_(5)^(-)and LiMg_(7)^(-).In all the doped clusters,the Li atom prefers to occupy the convex position.Simulated photoelectron spectra(PES),Infrared(IR),and Raman spectra of LiMg_(n)^(-)could be used as an essential evidence for identifying cluster structures experimentally in the future.Stability study reveals that a tower-like structure of LiMg_(9)^(-)has prominent stability and can be identified as a magic number cluster.The reason might be that there are both closed-shell 1S^(2)1P^(6)1D^(10)2S^(2) electronic configurations and stronger Li-Mg bonds caused by sp hybridization in the LiMg_(9)^(-)cluster.展开更多
It is still a challenging task to accurately and temperature-continuously express the thermodynamic properties and phase equilibrium behaviors of the salt-lake brine with multi-component,multitemperature and high conc...It is still a challenging task to accurately and temperature-continuously express the thermodynamic properties and phase equilibrium behaviors of the salt-lake brine with multi-component,multitemperature and high concentration.The essential subsystem of sulfate type brine,aqueous Li^(+)-Na^(+)-K^(+)-SO_(4)^(2-) and its subsystems across a temperature range from 250 K to 643 K are investigated with the improved comprehensive thermodynamic model.Liquid parameters(Δg_(IJ),Δh_(IJ),and ΔC_(p,IJ))associated with the contributions of Gibbs energy,enthalpy,and heat capacity to the binary interaction parameters,i.e.the temperature coefficients of eNRTL parameters formulated with a Gibbs Helmholtz expression,are determined via multi-objective optimization method.The solid constantsΔ_(f)G_(k)°^((298.15))andΔ_(f)H_(k)°^((298.15))of11 solid species occurred in the quaternary system are rebuilt from multi-temperature solubilities.The modeling results show the accurate representation of(1)solution properties and binary phase diagram at temperature ranges from eutectic points to 643 K;(2)isothermal phase diagrams for Li_(2)SO_(4)-Na_(2)SO_(4)-H_(2)O,Li_(2)SO_(4)-K_(2)SO_(4)-H_(2)O and Na_(2)SO_(4)-K_(2)SO_(4)-H_(2)O ternary systems.The predicted results of complete structure and polythermal phase diagram of ternary systems and the isothermal phase diagrams of quaternary system excellently match with the experimental data.展开更多
The Ti_(2)AlN-reinforced TiAl(WMS)composites with different contents of Ti_(2)AlN were prepared by an in situ method of reactive arc-melting technique.According to the results of X-ray diffraction(XRD)analysis,the Ti_...The Ti_(2)AlN-reinforced TiAl(WMS)composites with different contents of Ti_(2)AlN were prepared by an in situ method of reactive arc-melting technique.According to the results of X-ray diffraction(XRD)analysis,the Ti_(2)AlNreinforced WMS composites consist ofγ-TiAl,α_(2)-Ti_(3)Al,and Ti_(2)AlN phases.Microstructure analysis results indicate that Ti_(2)AlN reinforcements with rod-like in shape form in the WMS matrix with aα_(2)/γlamellar structure containing some bulk y phases.With volume fraction of Ti_(2)AlN increasing,the grain size of the composites decreases significantly and the elasticity modulus(E)increases.The compressive strength and compressive fracture strain of the composite with 3 vol%Ti_(2)AlN have a maximum value of 1,654 MPa and 22.5%,respectively,which are approximately improved by 45.84%and 29.31%,respectively,compared with that of the unreinforced WMS alloy.展开更多
The BaFe_(0.9)Sn_(0.1)O_(3)-BaCo_(0.02)^(Ⅱ)Co_(0.04)^(Ⅲ)Bi_(0.94)O_(3)composite thick films were prepared by screen printing.X-ray diffraction(XRD)analysis confirms that the composite films are still composed of BaF...The BaFe_(0.9)Sn_(0.1)O_(3)-BaCo_(0.02)^(Ⅱ)Co_(0.04)^(Ⅲ)Bi_(0.94)O_(3)composite thick films were prepared by screen printing.X-ray diffraction(XRD)analysis confirms that the composite films are still composed of BaFe_(0.9)Sn_(0.1)O_(3)-BaCo_(0.02)^(Ⅱ)Co_(0.04)^(Ⅲ)Bi_(0.94)O_(3)phases.For the prepared BaFe_(0.9)Sn_(0.1)O_(3)-BaCo_(0.02)^(Ⅱ)Co_(0.04)^(Ⅲ)Bi_(0.94)O_(3)composite thick films,a linear relationship between the logarithmic resistivity and the reciprocal of the absolute temperature is observed,indicating an excellent NTC thermistor characteristic.The values of resistivity at 25℃,thermistor constant and activation energy,decreasing with BaCo_(0.02)^(Ⅱ)Co_(0.04)^(Ⅲ)Bi_(0.94)O_(3)content increasing,are in the range of 8.9-92,990Ω·cm,1,126-3,777 K and 0.097-0.325 eV,respectively.Impedance analysis shows that at higher BaCo_(0.02)^(Ⅱ)Co_(0.04)^(Ⅲ)Bi_(0.94)O_(3)content,the electrical properties of the composite films are mainly attributed to the contribution of grains and grain boundaries.With the gradual decrease of BaCo_(0.02)^(Ⅱ)Co_(0.04)^(Ⅲ)Bi_(0.94)O_(3)content,the grain boundaries affect strongly the electrical properties of the composite films.展开更多
The phase transformations in ultrahigh molecular weight polyethylene(UHMWPE)gel-films upon superdrawing have been studied by X-ray diffraction and high resolution solid state ^(13)C NMR.The morphological change and mo...The phase transformations in ultrahigh molecular weight polyethylene(UHMWPE)gel-films upon superdrawing have been studied by X-ray diffraction and high resolution solid state ^(13)C NMR.The morphological change and molecular motions in the crystalline phase,amorphous phase and interphase are dis- cussed according to the ^(13)C nuclear relaxation time(T_(1c),T_(2c)results.A brief interpretation to the three or four T_(1c)values in the crystalline phase is presented.It is found that the component with the highest T_(1c) (T_(1c)~α)plays a key role in the forming of 'Shish-Kebab' microfibril which determines the sample strength and modulus,namely,the greater the T_(1c)~α,the higher the modulus and strength of the drawn UHMWPE gel-film.These results support the 'Shish-Kebabs' model in crystalline polymers.展开更多
基金Funded by the National Natural Science Foundation of China(No.50175041 ,50275111)
文摘C ^＋ ion beam-assisted deposition was utilized to prepare deposit diamond-like carbon （ DLC ） film. With the help of a series of experiments such as Raman spectroscopy, FT-IR spectroscopy, AFM and nanoindentation , the DLC film has been recognized as hydrogenated DLC film and its tribologicul properties have been evaluated. The bull-on-disc testing results show that the hardness and the tribologicul properties of the DLC film produced by C^ ＋ ion beam- assisted deposition are improved significantly. DLC film produced by C ^＋ ion beam- assisted deposition is positive to have a prosperous tribologicul application in the near future.
基金Project supported by the National Natural Science Foundation of China(Grant No.11404008)the Innovation Training Program for College Students of Shanxi Province of China(Grant No.S201910721061)the Innovation Training Program for College Students of Baoji University of Arts and Sciences(Grant No.20191XJ087)。
文摘Bimetallic clusters have aroused tremendous interest because the property changes like structure,size,and composition have occurred.Herein,a structural search of the global minimum for anionic LiMg_(n)^(-)(n=2-11) clusters is performed using an efficient crystal structure analysis by particle swarm optimization(CALYPSO) structural searching program with subsequent density functional theory(DFT) calculations.A great variety of low energetic isomers are converged,and the most stable ones are confirmed by comparing their total energy of each size.It is found that the LiMg_(n)^(-)clusters are structurally consistent with corresponding Mg clusters anions except for LiMg_(5)^(-)and LiMg_(7)^(-).In all the doped clusters,the Li atom prefers to occupy the convex position.Simulated photoelectron spectra(PES),Infrared(IR),and Raman spectra of LiMg_(n)^(-)could be used as an essential evidence for identifying cluster structures experimentally in the future.Stability study reveals that a tower-like structure of LiMg_(9)^(-)has prominent stability and can be identified as a magic number cluster.The reason might be that there are both closed-shell 1S^(2)1P^(6)1D^(10)2S^(2) electronic configurations and stronger Li-Mg bonds caused by sp hybridization in the LiMg_(9)^(-)cluster.
基金financial support of the National Natural Science Foundation of China(U1707602,U1407204)Yangtze Scholars and Innovative Research Team in University of Education of China,the Innovative Research Team of Tianjin Municipal Education Commission(TD125004)。
文摘It is still a challenging task to accurately and temperature-continuously express the thermodynamic properties and phase equilibrium behaviors of the salt-lake brine with multi-component,multitemperature and high concentration.The essential subsystem of sulfate type brine,aqueous Li^(+)-Na^(+)-K^(+)-SO_(4)^(2-) and its subsystems across a temperature range from 250 K to 643 K are investigated with the improved comprehensive thermodynamic model.Liquid parameters(Δg_(IJ),Δh_(IJ),and ΔC_(p,IJ))associated with the contributions of Gibbs energy,enthalpy,and heat capacity to the binary interaction parameters,i.e.the temperature coefficients of eNRTL parameters formulated with a Gibbs Helmholtz expression,are determined via multi-objective optimization method.The solid constantsΔ_(f)G_(k)°^((298.15))andΔ_(f)H_(k)°^((298.15))of11 solid species occurred in the quaternary system are rebuilt from multi-temperature solubilities.The modeling results show the accurate representation of(1)solution properties and binary phase diagram at temperature ranges from eutectic points to 643 K;(2)isothermal phase diagrams for Li_(2)SO_(4)-Na_(2)SO_(4)-H_(2)O,Li_(2)SO_(4)-K_(2)SO_(4)-H_(2)O and Na_(2)SO_(4)-K_(2)SO_(4)-H_(2)O ternary systems.The predicted results of complete structure and polythermal phase diagram of ternary systems and the isothermal phase diagrams of quaternary system excellently match with the experimental data.
基金financially supported by the National Basic Research Program of China(No.2011CB605503)the Program of Introducing Talents of Discipline to Universities(No.B08040)。
文摘The Ti_(2)AlN-reinforced TiAl(WMS)composites with different contents of Ti_(2)AlN were prepared by an in situ method of reactive arc-melting technique.According to the results of X-ray diffraction(XRD)analysis,the Ti_(2)AlNreinforced WMS composites consist ofγ-TiAl,α_(2)-Ti_(3)Al,and Ti_(2)AlN phases.Microstructure analysis results indicate that Ti_(2)AlN reinforcements with rod-like in shape form in the WMS matrix with aα_(2)/γlamellar structure containing some bulk y phases.With volume fraction of Ti_(2)AlN increasing,the grain size of the composites decreases significantly and the elasticity modulus(E)increases.The compressive strength and compressive fracture strain of the composite with 3 vol%Ti_(2)AlN have a maximum value of 1,654 MPa and 22.5%,respectively,which are approximately improved by 45.84%and 29.31%,respectively,compared with that of the unreinforced WMS alloy.
基金the National Natural Science Foundation of China(No.51102055)the Natural Science Foundation of Guangxi(Nos.2010GXNSFA013036 and 2011GXNSFA018028)。
文摘The BaFe_(0.9)Sn_(0.1)O_(3)-BaCo_(0.02)^(Ⅱ)Co_(0.04)^(Ⅲ)Bi_(0.94)O_(3)composite thick films were prepared by screen printing.X-ray diffraction(XRD)analysis confirms that the composite films are still composed of BaFe_(0.9)Sn_(0.1)O_(3)-BaCo_(0.02)^(Ⅱ)Co_(0.04)^(Ⅲ)Bi_(0.94)O_(3)phases.For the prepared BaFe_(0.9)Sn_(0.1)O_(3)-BaCo_(0.02)^(Ⅱ)Co_(0.04)^(Ⅲ)Bi_(0.94)O_(3)composite thick films,a linear relationship between the logarithmic resistivity and the reciprocal of the absolute temperature is observed,indicating an excellent NTC thermistor characteristic.The values of resistivity at 25℃,thermistor constant and activation energy,decreasing with BaCo_(0.02)^(Ⅱ)Co_(0.04)^(Ⅲ)Bi_(0.94)O_(3)content increasing,are in the range of 8.9-92,990Ω·cm,1,126-3,777 K and 0.097-0.325 eV,respectively.Impedance analysis shows that at higher BaCo_(0.02)^(Ⅱ)Co_(0.04)^(Ⅲ)Bi_(0.94)O_(3)content,the electrical properties of the composite films are mainly attributed to the contribution of grains and grain boundaries.With the gradual decrease of BaCo_(0.02)^(Ⅱ)Co_(0.04)^(Ⅲ)Bi_(0.94)O_(3)content,the grain boundaries affect strongly the electrical properties of the composite films.
基金the National Natural Science Foundation of China
文摘The phase transformations in ultrahigh molecular weight polyethylene(UHMWPE)gel-films upon superdrawing have been studied by X-ray diffraction and high resolution solid state ^(13)C NMR.The morphological change and molecular motions in the crystalline phase,amorphous phase and interphase are dis- cussed according to the ^(13)C nuclear relaxation time(T_(1c),T_(2c)results.A brief interpretation to the three or four T_(1c)values in the crystalline phase is presented.It is found that the component with the highest T_(1c) (T_(1c)~α)plays a key role in the forming of 'Shish-Kebab' microfibril which determines the sample strength and modulus,namely,the greater the T_(1c)~α,the higher the modulus and strength of the drawn UHMWPE gel-film.These results support the 'Shish-Kebabs' model in crystalline polymers.
