In this study,HEA/AI composite interlayer was used to fabricate Ti/Mg bimetal composites by solidliquid compound casting process.The Al layer was prepared on the surface of TC4 alloy by hot dipping,and the FeCoNiCr HE...In this study,HEA/AI composite interlayer was used to fabricate Ti/Mg bimetal composites by solidliquid compound casting process.The Al layer was prepared on the surface of TC4 alloy by hot dipping,and the FeCoNiCr HEA layer was prepared by magnetron sputtering onto the Al layer.The influence of the HEA layer thickness and pouring temperature on interface evolution was investigated based on SEM observation and thermodynamic analysis.Results indicate that the sluggish diffusion effect of HEA can effectively inhibit the interfacial diffusion between Al and Mg,which is conducive to the formation of solid solution,especially when the thickness of HEA is 800 nm.With the increase of casting temperature from 720 ℃ to 730 ℃,740℃,and 750 ℃,α-Al(Mg),α-Al(Mg)+Al3Mg2,Al3Mg2+Al12Mg17,and Al12Mg17+δ-Mg are formed at the interface of Ti/Mg bimetal,respectively.When the thickness of the HEA layer is 800 nm and the pouring temperature is 720 ℃,the bonding strength of the Ti/Mg bimetal can reach the maximum of 93.6 MPa.展开更多
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
Artificial neural networks (ANN), being a sophisticated type of information processing system by imitating the neural system of human brain, can be used to investigate the effects of concentration of flux solution, te...Artificial neural networks (ANN), being a sophisticated type of information processing system by imitating the neural system of human brain, can be used to investigate the effects of concentration of flux solution, temperature of liquid aluminium, temperture of tools and pressure on thickness of the intermetallic layer at the interface between steel and aluminium under solid-liquid pressure bonding of steel and aluminium perfectly. The optimum thickness has been determined according to the value of the optimum shearing strength.展开更多
This paper describes numerical simulation on dispersion of the solid-liquid mixed fuel driven by explosion load. A model used in numerical calculation for dispersion of solid-liquid mixed fuel was established in this ...This paper describes numerical simulation on dispersion of the solid-liquid mixed fuel driven by explosion load. A model used in numerical calculation for dispersion of solid-liquid mixed fuel was established in this study. The concentration and turbulent intensity in the multiphase cloud of the solidliquid mixed fuel were obtained by numerical simulation. It was found that the fuel concentration tended to be 0.15 kg/m^3, the turbulence intensity tended to be 7 in 90 ms. The numerical results agree with those measured in the experiment.展开更多
The multiphase flow in the solid-liquid tank stirred with a new structure of Intermig impeller was analyzed by computational fluid dynamics(CFD).The Eulerian multiphase model and standard k-ε turbulence model were ad...The multiphase flow in the solid-liquid tank stirred with a new structure of Intermig impeller was analyzed by computational fluid dynamics(CFD).The Eulerian multiphase model and standard k-ε turbulence model were adopted to simulate the fluid flow,turbulent kinetic energy distribution,mixing performance and power consumption in a stirred tank.The simulation results were also verified by the water model experiments,and good agreement was achieved.The solid-liquid mixing performances of Intermig impeller with different blade structures were compared in detail.The results show that the improved Intermig impeller not only enhances the solid mixing and suspension,but also saves more than 20% power compared with the standard one.The inner blades have relatively little influence on power and the best angle of inner blades is 45°,while the outer blades affect greatly the power consumption and the optimized value is 45°.展开更多
To explore the complex thermal-mechanical-chemical behavior in the solid-liquid cast-roll bonding(SLCRB) of Cu/Al cladding strip, numerical simulations were conducted from both macro and micro scales. In macro-scale, ...To explore the complex thermal-mechanical-chemical behavior in the solid-liquid cast-roll bonding(SLCRB) of Cu/Al cladding strip, numerical simulations were conducted from both macro and micro scales. In macro-scale, with birth and death element method, a thermo-mechanical coupled finite element model(FEM) was set up to explore the temperature and contact pressure distribution at the Cu/Al bonding interface in the SLCRB process. Taking these macro-scale simulation results as boundary conditions, we simulated the atom diffusion law of the bonding interface by molecular dynamics(MD) in micro-scale. The results indicate that the temperature in Cu/Al bonding interface deceases from 700 to 320 ℃ from the entrance to the exit of caster, and the peak of contact pressure reaches up to 140 MPa. The interfacial diffusion thickness depends on temperature and rolling reduction, higher temperature results in larger thickness, and the rolling reduction below kiss point leads to significant elongation deformation of cladding strip which yields more newborn interface with fresh metal and make the diffusion layer thinner. The surface roughness of Cu strip was found to be benefit to atoms diffusion in the Cu/Al bonding interface. Meanwhile, combined with the SEM-EDS observation on the microstructure and composition in the bonding interface of the experimental samples acquired from the castrolling bite, it is revealed that the rolling reduction and severe elongation deformation in the solid-solid contact zone below kiss point guarantee the satisfactory metallurgical bonding with thin and smooth diffusion layer. The bonding mechanisms of reactive diffusion, mechanical interlocking and crack bonding are proved to coexist in the SLCRB process.展开更多
The extraction behavior of rare earths was studied by using paraffin with ceresin as a diluent containing1-phenyl-3-methyl-4-benzoyl-pyrazolone-5.In solid phase,the composition of complexes is REP<sub>3</sub&...The extraction behavior of rare earths was studied by using paraffin with ceresin as a diluent containing1-phenyl-3-methyl-4-benzoyl-pyrazolone-5.In solid phase,the composition of complexes is REP<sub>3</sub>.The equilib-rium extraction constants and pH<sub>1/2</sub> values of solid-liquid extraction are higher than those of normalliquid-liquid extraction.The extraction efficiency tends to maximum when the ratio of phases is 1:1.When theextraction temperature is higher than the melting point of paraffin and the extraction time is over 10 min,theextraction efficiency keeps constant.Moreover,the relationship among separation factor,equilibrium extrac-tion constant,pH<sub>1/2</sub> value and atomic number was obtained.The mechanism of solid-liquid extraction isanalogous to that of liquid-liquid extraction.展开更多
Silver nanoparticles were synthesized in reverse micelles consisting of sucrose fatty acid esters by dissolving reactant powder in the water pool of reverse micelles through the solid-liquid extraction. Silver nanopar...Silver nanoparticles were synthesized in reverse micelles consisting of sucrose fatty acid esters by dissolving reactant powder in the water pool of reverse micelles through the solid-liquid extraction. Silver nanoparticles having various sizes and shapes were obtained at high concentration. The size of silver nanoparticles was controlled by reaction temperature. Moreover, the size of silver nanoparticles was dependent upon the average esterification degree of sucrose fatty acid esters forming reverse micelles. The wavelength in the peaks, which corresponded upon the localized surface plasmon resonance of resultant silver nanoparticles, was correlated with their sizes.展开更多
We studied the solid-liquid transformation of low-grade solid potash deposit in Dalangtan Basin and simplified the liquid phase system.We did experiments to optimize conditions of the solid-liquid transformation.The
Solid liquid extraction of copper ion (I) with 2, 9-dimethyl-l, l0-phenanthroline (neo-cuproine, DMP) into molten naphthalene followed by chloroform spectrophotometric determination has been studied experimentally...Solid liquid extraction of copper ion (I) with 2, 9-dimethyl-l, l0-phenanthroline (neo-cuproine, DMP) into molten naphthalene followed by chloroform spectrophotometric determination has been studied experimentally. The ternary complex Cu(I)-DMP-ClO4 was extracted quantitatively into molten naphthalene in the range of pH from 5 to 6 at 85℃. Absorbance was spectrophotometrically determined at 459 nm against the reagent blank after the solid naphthalene layer was anhydrously dissolved in chloroform. Beer?(r)s law is obeyed over a concentration range of 0.5- 70 μg/mL. The molar absorptivity and Sandell’s sensitivity are 1.0×104 L/(mol.cm) and 0.0099 μg·cm2 respectively. In addition, the various conditions on determination and the interference of coexisted ions were discussed, and the method was applied to the determination of copper ion both in tea samples and cadmium sulfate reagents. The results are in good agreement with those obtained by ICP AES method.展开更多
Solid-liquid suspension in an agitated tank with a draft tube was investigated witha newly developed infrared turbidimeter for measuring solid concentration.The diameter of theflared inlet transition tube and the dist...Solid-liquid suspension in an agitated tank with a draft tube was investigated witha newly developed infrared turbidimeter for measuring solid concentration.The diameter of theflared inlet transition tube and the distance from the inlet to the tank bottom are two importantparameters for draft tube design The NAX-4 impeller,developed in this study,is characterized byits high flow efficiency and low power consumption.Some modifications are made to the Bald′smodel by considering the effects of solid concentration and fluid viscosity on the critical speed forcomplete off-bottom suspension.The modified equation fits the experimental data satisfactority andcan be used in scale-up展开更多
The paper presents a new relationship betweenthe three surface tensions on the solid-liquid-vaporinterface, γ<sub>sl</sub>-γ<sub>sv</sub>+γ<sub>lv</sub>cosθ=βin order to unders...The paper presents a new relationship betweenthe three surface tensions on the solid-liquid-vaporinterface, γ<sub>sl</sub>-γ<sub>sv</sub>+γ<sub>lv</sub>cosθ=βin order to understandthe wetting on the liquid-solid interface in the caseof active adsorption.The authors suggest a newforce“apparent active adsorption force”βto takepart in the balance at the three interface lines ofcontact in the solid-liquid-vapor phases,its dimen-sion isβ=Σα<sub>i</sub>RT(Γ<sub>i</sub><sup>sl</sup>-Γ<sub>i</sub><sup>sv</sup>+Γ<sub>i</sub><sup>lv</sup>cosθ),and its directionis dependent on the sign of β,whenβis a positive,the direction is agree with surface tension of the sol-id-vapor interface γ and vice versa.展开更多
The extraction behavior of Sm(III), Eu(III),Er(III) and Yb(III) with 1- nitroso -2-naphthol (HA) in paraffin has been studied. The composition of extracted complexes has been determined to be LnA3 by slope analysis me...The extraction behavior of Sm(III), Eu(III),Er(III) and Yb(III) with 1- nitroso -2-naphthol (HA) in paraffin has been studied. The composition of extracted complexes has been determined to be LnA3 by slope analysis method. The effect of temperature on extraction system is also investigated and thermodynamic parameters are obtained.展开更多
To reveal the formation mechanism and main influencing factors of C-segregation in high carbon steel under different solidification rates(40,80,160,200 and 320μm·s^(-1)),the enrichment characteristics of carbon ...To reveal the formation mechanism and main influencing factors of C-segregation in high carbon steel under different solidification rates(40,80,160,200 and 320μm·s^(-1)),the enrichment characteristics of carbon atoms in the solid-liquid zone of Fe-0.61%C steel were studied using a zone melting liquid metal cooling apparatus and electron probe microanalysis.The relationships among micro-segregation of carbon atoms,solid-liquid interface morphology and solidification rate were fully discussed.The results show that large dendrite spacing and a slow-moving dendritic interface create less resistance and more time for the migration of interdendritic carbon atoms to liquid zone.This results in the continuous enrichment of carbon atoms in liquid zone,further expands the solid-liquid temperature range,prolongs the solidification time of molten steel,and causes the formation of carbon micro-segregation at the solidification end as the solidification rate is 40μm·s^(-1).Conversely,abundant and elongated secondary dendrite arms with small spacing seriously impede the diffusion of interdendritic carbon-rich molten steel to liquid zone.As a result,there is only obvious dendrite segregation,but little difference in the carbon content along the solidification direction as solidification rate exceeds 200μm·s^(-1).展开更多
The flow with solid-liquid two-phase media inside centrifugal pumps is very complicated and the relevant method for the hydraulic design is still immature so far.There exist two main problems in the operation of the t...The flow with solid-liquid two-phase media inside centrifugal pumps is very complicated and the relevant method for the hydraulic design is still immature so far.There exist two main problems in the operation of the two-phase flow pumps,i.e.,low overall efficiency and severe abrasion.In this study,the three-dimensional,steady,incompressible,and turbulent solid-liquid two-phase flows in a low-specific-speed centrifugal pump are numerically simulated and analyzed by using a computational fluid dynamics(CFD) code based on the mixture model of the two-phase flow and the RNG k-two-equation turbulence model,in which the influences of rotation and curvature are fully taken into account.The coupling between impeller and volute is implemented by means of the frozen rotor method.The simulation results predicted indicate that the solid phase properties in two-phase flow,especially the concentration,the particle diameter and the density,have strong effects on the hydraulic performance of the pump.Both the pump head and the efficiency are reduced with increasing particle diameter or concentration.However,the effect of particle density on the performance is relatively minor.An obvious jet-wake flow structure is presented near the volute tongue and becomes more remarkable with increasing solid phase concentration.The suction side of the blade is subject to much more severe abrasion than the pressure side.The obtained results preliminarily reveal the characteristics of solid-liquid two-phase flow in the centrifugal pump,and are helpful for improvement and empirical correction in the hydraulic design of centrifugal pumps.展开更多
Terephthalic acid(PTA) is practically one of the main materials of polyester. Its corresponding solid-liquid equilibrium data will provide essential support for industry design and further theoretical studies. In this...Terephthalic acid(PTA) is practically one of the main materials of polyester. Its corresponding solid-liquid equilibrium data will provide essential support for industry design and further theoretical studies. In this work,solid-liquid equilibriums of terephthalic acid in four solvents, N,N-dimethylformamide, N,N-dimethylacetamide,dimethylsulphoxide and N-methyl-2-ketopyrrolidene, were determined in the temperature range from 293.15 K to 364.6 K by dynamic method. All these data were regressed by λh model, Wilson model and NRTL model, average absolute relative deviations of which are 1.25%, 15.02% and 7.22% respectively. It indicates that λh model is mostsuitable for description of the solid-liquid equilibrium containing PTA.展开更多
The transient behavior of centrifugal pumps during transient operating periods,such as startup and stopping,has drawn more and more attention recently because of urgent needs in engineering.Up to now,almost all the ex...The transient behavior of centrifugal pumps during transient operating periods,such as startup and stopping,has drawn more and more attention recently because of urgent needs in engineering.Up to now,almost all the existing studies on this behavior are limited to using water as working fluid.The study on the transient behavior related to solid-liquid two-phase flow has not been seen yet.In order to explore the transient characteristics of a high specific-speed centrifugal pump during startup period delivering the pure water and solid-liquid two-phase flow,the transient flows inside the pump are numerically simulated using the dynamic mesh method.The variable rotational speed and flow rate with time obtained from experiment are best fitted as the function of time,and are written into computational fluid dynamics(CFD)code-FLUENT by using a user defined function.The predicted heads are compared with experimental results when pumping pure water.The results show that the difference in the transient performance during startup period is very obvious between water and solid-liquid two-phase flow during the later stage of startup process.Moreover,the time for the solid-liquid two-phase flow to achieve a stable condition is longer than that for water.The solid-liquid two-phase flow results in a higher impeller shaft power,a larger dynamic reaction force,a more violent fluctuation in pressure and a reduced stable pressure rise comparing with water.The research may be useful to understanding on the transient behavior of a centrifugal pump under a solid-liquid two-phase flow during startup period.展开更多
Based on RNG k-ε turbulence model and sliding grid technique, solid-liquid two-phase three-dimensional(3-D) unsteady turbulence of full passage in slurry pump was simulated by means of Fluent software. The effects of...Based on RNG k-ε turbulence model and sliding grid technique, solid-liquid two-phase three-dimensional(3-D) unsteady turbulence of full passage in slurry pump was simulated by means of Fluent software. The effects of unsteady flow characteristics on solid-liquid two-phase flow and pump performance were researched under design condition. The results show that clocking effect has a significant influence on the flow in pump, and the fluctuation of flow velocity and pressure is obvious, particularly near the volute tongue, at the position of small sections of volute and within diffuser. Clocking effect has a more influence on liquid-phase than on solid-phase, and the wake-jet structure of relative velocity of solid-phase is less obvious than liquid-phase near the volute tongue and the impeller passage outlet. The fluctuation of relative velocity of solid-phase flow is 7.6% smaller than liquid-phase flow at the impeller outlet on circular path. Head and radial forces of the impeller are 8.1% and 85.7% of fluctuation, respectively. The results provide a theoretical basis for further research for turbulence, improving efficient, reducing the hydraulic losses and wear. Finally, field tests were carried out to verify the operation and wear of slurry pump.展开更多
D 葡萄糖的溶解度上的试验性的数据, D 果糖并且在从 273.2 ~ 293.2 K 由水和乙醇组成的混合溶剂的蔗糖被决定。D 葡萄糖的溶解度, D 果糖并且蔗糖作为内容在混合溶剂增加了的乙醇减少了。D 葡萄糖的溶解度, D 果糖并且蔗糖与减少...D 葡萄糖的溶解度上的试验性的数据, D 果糖并且在从 273.2 ~ 293.2 K 由水和乙醇组成的混合溶剂的蔗糖被决定。D 葡萄糖的溶解度, D 果糖并且蔗糖作为内容在混合溶剂增加了的乙醇减少了。D 葡萄糖的溶解度, D 果糖并且蔗糖与减少的平衡温度减少了。修改 UNIQUAC 模型, S-UNIFAC 模型和 mS-UNIFAC 模型被使用预言稳固液体的 equilibria。预言结果被比较并且讨论。更好的预言精确性用修改 UNIQUAC 模型被产生。展开更多
Three-dimensional solid-liquid flow is mathematically formulated by means of the 'two-fluid' approach and the two-phase k-ε-AP turbulence model. The turbulent fluctuation correlations appearing in the Reynold...Three-dimensional solid-liquid flow is mathematically formulated by means of the 'two-fluid' approach and the two-phase k-ε-AP turbulence model. The turbulent fluctuation correlations appearing in the Reynolds time averaged governing equations are fully incorporated. The solid-liquid flow field and solid concentration distribution in baffled stirred tanks with a standard Rushton impeller are numerically simulated using an improved 'inner-outer'iterative procedure. The flow pattern is identified via the velocity vector plots and a recirculation loop with higher solid concentration is observed in the central vicinity beneath the impeller. Comparison of the simulation with experimental data on the mean velocities and the turbulence quantities of the solid phase is made and quite reasonable agreement is obtained except for the impeller swept volume. The counterpart of liquid phase is presented as well.The predicted solid concentration distribution for three experimental cases with the average solid concentration up to 20% is also found to agree reasonably with the experimental results published in the literature.展开更多
基金financial supports from the National Natural Science Foundation of China (No. 51875062)China Postdoctoral Science Foundation (No. 2021M700567)。
文摘In this study,HEA/AI composite interlayer was used to fabricate Ti/Mg bimetal composites by solidliquid compound casting process.The Al layer was prepared on the surface of TC4 alloy by hot dipping,and the FeCoNiCr HEA layer was prepared by magnetron sputtering onto the Al layer.The influence of the HEA layer thickness and pouring temperature on interface evolution was investigated based on SEM observation and thermodynamic analysis.Results indicate that the sluggish diffusion effect of HEA can effectively inhibit the interfacial diffusion between Al and Mg,which is conducive to the formation of solid solution,especially when the thickness of HEA is 800 nm.With the increase of casting temperature from 720 ℃ to 730 ℃,740℃,and 750 ℃,α-Al(Mg),α-Al(Mg)+Al3Mg2,Al3Mg2+Al12Mg17,and Al12Mg17+δ-Mg are formed at the interface of Ti/Mg bimetal,respectively.When the thickness of the HEA layer is 800 nm and the pouring temperature is 720 ℃,the bonding strength of the Ti/Mg bimetal can reach the maximum of 93.6 MPa.
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.
文摘Artificial neural networks (ANN), being a sophisticated type of information processing system by imitating the neural system of human brain, can be used to investigate the effects of concentration of flux solution, temperature of liquid aluminium, temperture of tools and pressure on thickness of the intermetallic layer at the interface between steel and aluminium under solid-liquid pressure bonding of steel and aluminium perfectly. The optimum thickness has been determined according to the value of the optimum shearing strength.
基金supported by National Key R&D Program of China(No.2016YFC0801800)the opening project of State Key Laboratory of Explosion Science and Technology(Beijing Institute ofTechnology)(No.KFJJ18-03M)
文摘This paper describes numerical simulation on dispersion of the solid-liquid mixed fuel driven by explosion load. A model used in numerical calculation for dispersion of solid-liquid mixed fuel was established in this study. The concentration and turbulent intensity in the multiphase cloud of the solidliquid mixed fuel were obtained by numerical simulation. It was found that the fuel concentration tended to be 0.15 kg/m^3, the turbulence intensity tended to be 7 in 90 ms. The numerical results agree with those measured in the experiment.
基金supported by the National Natural Science Foundation of China (U1760120, U1508217)National Key R&D Program of China (2017YFC0210403, 2017YFC0210404)Shenyang Science & Technology Project (17-500-8-01)。
文摘The multiphase flow in the solid-liquid tank stirred with a new structure of Intermig impeller was analyzed by computational fluid dynamics(CFD).The Eulerian multiphase model and standard k-ε turbulence model were adopted to simulate the fluid flow,turbulent kinetic energy distribution,mixing performance and power consumption in a stirred tank.The simulation results were also verified by the water model experiments,and good agreement was achieved.The solid-liquid mixing performances of Intermig impeller with different blade structures were compared in detail.The results show that the improved Intermig impeller not only enhances the solid mixing and suspension,but also saves more than 20% power compared with the standard one.The inner blades have relatively little influence on power and the best angle of inner blades is 45°,while the outer blades affect greatly the power consumption and the optimized value is 45°.
基金Funded by the General Program of National Natural Science Foundation of China(Nos.51474189 and 51674222)the Excellent Youth Foundation of Hebei Scientific Committee,China(No.E2018203446)the Scientific Research Foundation of the Higher Education Institutions of Hebei Province,China(No.QN2015214)
文摘To explore the complex thermal-mechanical-chemical behavior in the solid-liquid cast-roll bonding(SLCRB) of Cu/Al cladding strip, numerical simulations were conducted from both macro and micro scales. In macro-scale, with birth and death element method, a thermo-mechanical coupled finite element model(FEM) was set up to explore the temperature and contact pressure distribution at the Cu/Al bonding interface in the SLCRB process. Taking these macro-scale simulation results as boundary conditions, we simulated the atom diffusion law of the bonding interface by molecular dynamics(MD) in micro-scale. The results indicate that the temperature in Cu/Al bonding interface deceases from 700 to 320 ℃ from the entrance to the exit of caster, and the peak of contact pressure reaches up to 140 MPa. The interfacial diffusion thickness depends on temperature and rolling reduction, higher temperature results in larger thickness, and the rolling reduction below kiss point leads to significant elongation deformation of cladding strip which yields more newborn interface with fresh metal and make the diffusion layer thinner. The surface roughness of Cu strip was found to be benefit to atoms diffusion in the Cu/Al bonding interface. Meanwhile, combined with the SEM-EDS observation on the microstructure and composition in the bonding interface of the experimental samples acquired from the castrolling bite, it is revealed that the rolling reduction and severe elongation deformation in the solid-solid contact zone below kiss point guarantee the satisfactory metallurgical bonding with thin and smooth diffusion layer. The bonding mechanisms of reactive diffusion, mechanical interlocking and crack bonding are proved to coexist in the SLCRB process.
文摘The extraction behavior of rare earths was studied by using paraffin with ceresin as a diluent containing1-phenyl-3-methyl-4-benzoyl-pyrazolone-5.In solid phase,the composition of complexes is REP<sub>3</sub>.The equilib-rium extraction constants and pH<sub>1/2</sub> values of solid-liquid extraction are higher than those of normalliquid-liquid extraction.The extraction efficiency tends to maximum when the ratio of phases is 1:1.When theextraction temperature is higher than the melting point of paraffin and the extraction time is over 10 min,theextraction efficiency keeps constant.Moreover,the relationship among separation factor,equilibrium extrac-tion constant,pH<sub>1/2</sub> value and atomic number was obtained.The mechanism of solid-liquid extraction isanalogous to that of liquid-liquid extraction.
文摘Silver nanoparticles were synthesized in reverse micelles consisting of sucrose fatty acid esters by dissolving reactant powder in the water pool of reverse micelles through the solid-liquid extraction. Silver nanoparticles having various sizes and shapes were obtained at high concentration. The size of silver nanoparticles was controlled by reaction temperature. Moreover, the size of silver nanoparticles was dependent upon the average esterification degree of sucrose fatty acid esters forming reverse micelles. The wavelength in the peaks, which corresponded upon the localized surface plasmon resonance of resultant silver nanoparticles, was correlated with their sizes.
基金supported by National Natural Science Foundation of China (grant NO. 21373252)
文摘We studied the solid-liquid transformation of low-grade solid potash deposit in Dalangtan Basin and simplified the liquid phase system.We did experiments to optimize conditions of the solid-liquid transformation.The
基金This research was financially supported by the project KJCXGC-01 of Northwest Normal University, China.
文摘Solid liquid extraction of copper ion (I) with 2, 9-dimethyl-l, l0-phenanthroline (neo-cuproine, DMP) into molten naphthalene followed by chloroform spectrophotometric determination has been studied experimentally. The ternary complex Cu(I)-DMP-ClO4 was extracted quantitatively into molten naphthalene in the range of pH from 5 to 6 at 85℃. Absorbance was spectrophotometrically determined at 459 nm against the reagent blank after the solid naphthalene layer was anhydrously dissolved in chloroform. Beer?(r)s law is obeyed over a concentration range of 0.5- 70 μg/mL. The molar absorptivity and Sandell’s sensitivity are 1.0×104 L/(mol.cm) and 0.0099 μg·cm2 respectively. In addition, the various conditions on determination and the interference of coexisted ions were discussed, and the method was applied to the determination of copper ion both in tea samples and cadmium sulfate reagents. The results are in good agreement with those obtained by ICP AES method.
文摘Solid-liquid suspension in an agitated tank with a draft tube was investigated witha newly developed infrared turbidimeter for measuring solid concentration.The diameter of theflared inlet transition tube and the distance from the inlet to the tank bottom are two importantparameters for draft tube design The NAX-4 impeller,developed in this study,is characterized byits high flow efficiency and low power consumption.Some modifications are made to the Bald′smodel by considering the effects of solid concentration and fluid viscosity on the critical speed forcomplete off-bottom suspension.The modified equation fits the experimental data satisfactority andcan be used in scale-up
文摘The paper presents a new relationship betweenthe three surface tensions on the solid-liquid-vaporinterface, γ<sub>sl</sub>-γ<sub>sv</sub>+γ<sub>lv</sub>cosθ=βin order to understandthe wetting on the liquid-solid interface in the caseof active adsorption.The authors suggest a newforce“apparent active adsorption force”βto takepart in the balance at the three interface lines ofcontact in the solid-liquid-vapor phases,its dimen-sion isβ=Σα<sub>i</sub>RT(Γ<sub>i</sub><sup>sl</sup>-Γ<sub>i</sub><sup>sv</sup>+Γ<sub>i</sub><sup>lv</sup>cosθ),and its directionis dependent on the sign of β,whenβis a positive,the direction is agree with surface tension of the sol-id-vapor interface γ and vice versa.
文摘The extraction behavior of Sm(III), Eu(III),Er(III) and Yb(III) with 1- nitroso -2-naphthol (HA) in paraffin has been studied. The composition of extracted complexes has been determined to be LnA3 by slope analysis method. The effect of temperature on extraction system is also investigated and thermodynamic parameters are obtained.
基金support from the State Key Laboratory of Refractories and Metallurgy(Wuhan University of Science and Technology)(Grant No.G201902)the National Natural Science Foundation of China(Grant Nos.51874001,U1760108)。
文摘To reveal the formation mechanism and main influencing factors of C-segregation in high carbon steel under different solidification rates(40,80,160,200 and 320μm·s^(-1)),the enrichment characteristics of carbon atoms in the solid-liquid zone of Fe-0.61%C steel were studied using a zone melting liquid metal cooling apparatus and electron probe microanalysis.The relationships among micro-segregation of carbon atoms,solid-liquid interface morphology and solidification rate were fully discussed.The results show that large dendrite spacing and a slow-moving dendritic interface create less resistance and more time for the migration of interdendritic carbon atoms to liquid zone.This results in the continuous enrichment of carbon atoms in liquid zone,further expands the solid-liquid temperature range,prolongs the solidification time of molten steel,and causes the formation of carbon micro-segregation at the solidification end as the solidification rate is 40μm·s^(-1).Conversely,abundant and elongated secondary dendrite arms with small spacing seriously impede the diffusion of interdendritic carbon-rich molten steel to liquid zone.As a result,there is only obvious dendrite segregation,but little difference in the carbon content along the solidification direction as solidification rate exceeds 200μm·s^(-1).
基金supported by National Natural Science Foundation of China (Grant No. 21076198)Zhejiang Provincial Natural Science Foundation of China (Granted No. R1100530)National Basic Research Program of China (973 Program,Grant No. 2009CB724303)
文摘The flow with solid-liquid two-phase media inside centrifugal pumps is very complicated and the relevant method for the hydraulic design is still immature so far.There exist two main problems in the operation of the two-phase flow pumps,i.e.,low overall efficiency and severe abrasion.In this study,the three-dimensional,steady,incompressible,and turbulent solid-liquid two-phase flows in a low-specific-speed centrifugal pump are numerically simulated and analyzed by using a computational fluid dynamics(CFD) code based on the mixture model of the two-phase flow and the RNG k-two-equation turbulence model,in which the influences of rotation and curvature are fully taken into account.The coupling between impeller and volute is implemented by means of the frozen rotor method.The simulation results predicted indicate that the solid phase properties in two-phase flow,especially the concentration,the particle diameter and the density,have strong effects on the hydraulic performance of the pump.Both the pump head and the efficiency are reduced with increasing particle diameter or concentration.However,the effect of particle density on the performance is relatively minor.An obvious jet-wake flow structure is presented near the volute tongue and becomes more remarkable with increasing solid phase concentration.The suction side of the blade is subject to much more severe abrasion than the pressure side.The obtained results preliminarily reveal the characteristics of solid-liquid two-phase flow in the centrifugal pump,and are helpful for improvement and empirical correction in the hydraulic design of centrifugal pumps.
基金Supported by China Petroleum & Chemical Corporation(No.200049).
文摘Terephthalic acid(PTA) is practically one of the main materials of polyester. Its corresponding solid-liquid equilibrium data will provide essential support for industry design and further theoretical studies. In this work,solid-liquid equilibriums of terephthalic acid in four solvents, N,N-dimethylformamide, N,N-dimethylacetamide,dimethylsulphoxide and N-methyl-2-ketopyrrolidene, were determined in the temperature range from 293.15 K to 364.6 K by dynamic method. All these data were regressed by λh model, Wilson model and NRTL model, average absolute relative deviations of which are 1.25%, 15.02% and 7.22% respectively. It indicates that λh model is mostsuitable for description of the solid-liquid equilibrium containing PTA.
基金supported by National Natural Science Foundation of China(Grant Nos.51076144,51276172)Zhejiang Provincial Natural Science Foundation of China(Grant Nos.R1100530,LY12E06002)National Basic Research Program of China(973 Program,Grant No.2009CB724303)
文摘The transient behavior of centrifugal pumps during transient operating periods,such as startup and stopping,has drawn more and more attention recently because of urgent needs in engineering.Up to now,almost all the existing studies on this behavior are limited to using water as working fluid.The study on the transient behavior related to solid-liquid two-phase flow has not been seen yet.In order to explore the transient characteristics of a high specific-speed centrifugal pump during startup period delivering the pure water and solid-liquid two-phase flow,the transient flows inside the pump are numerically simulated using the dynamic mesh method.The variable rotational speed and flow rate with time obtained from experiment are best fitted as the function of time,and are written into computational fluid dynamics(CFD)code-FLUENT by using a user defined function.The predicted heads are compared with experimental results when pumping pure water.The results show that the difference in the transient performance during startup period is very obvious between water and solid-liquid two-phase flow during the later stage of startup process.Moreover,the time for the solid-liquid two-phase flow to achieve a stable condition is longer than that for water.The solid-liquid two-phase flow results in a higher impeller shaft power,a larger dynamic reaction force,a more violent fluctuation in pressure and a reduced stable pressure rise comparing with water.The research may be useful to understanding on the transient behavior of a centrifugal pump under a solid-liquid two-phase flow during startup period.
基金Project(51375498)supported by the National Natural Science Foundation of China
文摘Based on RNG k-ε turbulence model and sliding grid technique, solid-liquid two-phase three-dimensional(3-D) unsteady turbulence of full passage in slurry pump was simulated by means of Fluent software. The effects of unsteady flow characteristics on solid-liquid two-phase flow and pump performance were researched under design condition. The results show that clocking effect has a significant influence on the flow in pump, and the fluctuation of flow velocity and pressure is obvious, particularly near the volute tongue, at the position of small sections of volute and within diffuser. Clocking effect has a more influence on liquid-phase than on solid-phase, and the wake-jet structure of relative velocity of solid-phase is less obvious than liquid-phase near the volute tongue and the impeller passage outlet. The fluctuation of relative velocity of solid-phase flow is 7.6% smaller than liquid-phase flow at the impeller outlet on circular path. Head and radial forces of the impeller are 8.1% and 85.7% of fluctuation, respectively. The results provide a theoretical basis for further research for turbulence, improving efficient, reducing the hydraulic losses and wear. Finally, field tests were carried out to verify the operation and wear of slurry pump.
基金Supported by the National Science and Technology Major Project (2009ZX09313-036) the China Postdoctoral Science Foundation (20090461360) the Zhejiang Provincial Education Department Projects (Y200907556)
文摘D 葡萄糖的溶解度上的试验性的数据, D 果糖并且在从 273.2 ~ 293.2 K 由水和乙醇组成的混合溶剂的蔗糖被决定。D 葡萄糖的溶解度, D 果糖并且蔗糖作为内容在混合溶剂增加了的乙醇减少了。D 葡萄糖的溶解度, D 果糖并且蔗糖与减少的平衡温度减少了。修改 UNIQUAC 模型, S-UNIFAC 模型和 mS-UNIFAC 模型被使用预言稳固液体的 equilibria。预言结果被比较并且讨论。更好的预言精确性用修改 UNIQUAC 模型被产生。
文摘Three-dimensional solid-liquid flow is mathematically formulated by means of the 'two-fluid' approach and the two-phase k-ε-AP turbulence model. The turbulent fluctuation correlations appearing in the Reynolds time averaged governing equations are fully incorporated. The solid-liquid flow field and solid concentration distribution in baffled stirred tanks with a standard Rushton impeller are numerically simulated using an improved 'inner-outer'iterative procedure. The flow pattern is identified via the velocity vector plots and a recirculation loop with higher solid concentration is observed in the central vicinity beneath the impeller. Comparison of the simulation with experimental data on the mean velocities and the turbulence quantities of the solid phase is made and quite reasonable agreement is obtained except for the impeller swept volume. The counterpart of liquid phase is presented as well.The predicted solid concentration distribution for three experimental cases with the average solid concentration up to 20% is also found to agree reasonably with the experimental results published in the literature.