The precipitating regulation and mechanism of TCP phase (μ phase and σ phase) are studied, using electron hole number (EHN) theory, phase analysis technology and TEM observation. The results indicate that the EHN i...The precipitating regulation and mechanism of TCP phase (μ phase and σ phase) are studied, using electron hole number (EHN) theory, phase analysis technology and TEM observation. The results indicate that the EHN in studied alloy is 2.311-2.348 which is higher than that of critical EHN of μ phase precipitate (2.30), so μ phase could precipitate if there is enough thermo-exposition. In contrast, the calculated EHN is less than that of critical EHN of σ phase precipitate (2.52). However the σ phase is also observed by TEM. Enrich of Cr and Mo around γ phase after γ′phase precipitated leads to σ phase precipitated.展开更多
Phase change absorbents for CO_(2)are of great interest because they are expected to greatly reduce the heat energy consumption during the regeneration process.Compared with other phase change absorbents,monoethanolam...Phase change absorbents for CO_(2)are of great interest because they are expected to greatly reduce the heat energy consumption during the regeneration process.Compared with other phase change absorbents,monoethanolamine(MEA)-sulfolane-water is inexpensive and has a fast absorption rate.It is one of the most promising solvents for large-scale industrial applications.Therefore,this study investigates the mass transfer performance of this phase change system in the process of CO_(2)absorption in a packed tower.By comparing the phase change absorbent and the ordinary absorbent,it is concluded that the use of MEA/sulfolane phase change absorbent has significantly improved mass transfer efficiency compared to a single MEA absorbent at the same concentration.In the 4 mol·L^(-1)MEA/5 mol·L^(-1)sulfolane system,the CO_(2)loading of the upper liquid phase after phase separation is almost zero,while the volume of the lower liquid phase sent to the desorption operation is about half of the total volume of the absorbent,which greatly reduces the energy consumption.This study also investigates the influence of operating parameters such as lean CO_(2)loading,gas and liquid flow rates,CO_(2)partial pressure,and temperature on the volumetric mass transfer coefficient(K_(G)α_(V)).The research shows that K_(G)α_(V) increases with increasing liquid flow rate and decreases with the increase of lean CO_(2)loading and CO_(2)partial pressure,while the inert gas flow rate and temperature have little effect on K_(G)α_(V).In addition,based on the principle of phase change absorption,a predictive equation for the K_(G)α_(V) of MEA-sulfolane in the packed tower was established.The K_(G)α_(V) obtained from the experiment is consistent with the model prediction,and the absolute average deviation(AAD)is 7.8%.展开更多
The volume fraction and morphology of the TCP-phase formed in two kinds of Ni- Mo-Cr-Re superalloys under different heat treatment conditions were investigated in this paper. In Re-5% alloy, with increasing of the hea...The volume fraction and morphology of the TCP-phase formed in two kinds of Ni- Mo-Cr-Re superalloys under different heat treatment conditions were investigated in this paper. In Re-5% alloy, with increasing of the heat treatment temperature and prolonging the holding time, the volume fraction of TCP-phase decreased and the TCP-phase size increased. At relatively lower temperature, the TCP-phase prefers to present in the dendrite cores. In Re-10% alloy, the volume fraction and size have the same change tendency as that of in Re-5% alloy, but the morphology will change from needle-like and block-like to sphere when the temperature increases. The TCP-phases formed in these two Ni-Mo-Cr-Re alloys are σ and P phase.展开更多
A rapid and simple preconcentration step applying packed-fiber solid-phase extraction columns has been investigated to vitamin B12. The extraction performance of the new method was investigated preliminarily on vitami...A rapid and simple preconcentration step applying packed-fiber solid-phase extraction columns has been investigated to vitamin B12. The extraction performance of the new method was investigated preliminarily on vitamin functional drink. The analysis used a reversed-phase C18 column, with a photo-diode array detector at 220 nm. The samples were preconcentrated with packed-fiber solid-phase extraction columns. Good linearity was observed in vitamin functional drink. The repeatability of extraction performance, expressed as relative standard deviations, was from 3.5% to 4.3%. The limit of detection （LOD） is 5 ng mL^-1 （S/N = 3）. Finally, the method had been applied for the determination of vitamin B12 in vitamin functional drink.展开更多
Overall dispersed side volumetric mare transfer coeffcieats for protein and amino acids were measured in continuous countercurreat PEG4000/KHP aqueous two-phase systems in a 57 mm I.D. packed extraction column. A mode...Overall dispersed side volumetric mare transfer coeffcieats for protein and amino acids were measured in continuous countercurreat PEG4000/KHP aqueous two-phase systems in a 57 mm I.D. packed extraction column. A model for overall dispersed side volumetric mass transfer coefficients was derived by describing the motion of the drops based upon Navier-Stokes equation combined with the relationship between mass transfer coefficients and the drop velocity. The model provides good predictions and can be successfully used in aqueous two-phase extraction. The awrage relative deviation between calculated values and experimental date ranges from 8% to 14%.展开更多
计算机网络发展初期阶段,许多研究机构、计算机厂商和公司都推出了自己的网络系统,然而它们之间没有兼容性可言,也无法相互通信。为了解决网络之间兼容性的问题,国际标准组织ISO(International Standard Organized)于1984提出了开放系...计算机网络发展初期阶段,许多研究机构、计算机厂商和公司都推出了自己的网络系统,然而它们之间没有兼容性可言,也无法相互通信。为了解决网络之间兼容性的问题,国际标准组织ISO(International Standard Organized)于1984提出了开放系统互边参考模型OSI/RM(Open System Interconnection/Reference Model),该模型很快成为了计算机网络体系结构中理论模型。展开更多
文摘The precipitating regulation and mechanism of TCP phase (μ phase and σ phase) are studied, using electron hole number (EHN) theory, phase analysis technology and TEM observation. The results indicate that the EHN in studied alloy is 2.311-2.348 which is higher than that of critical EHN of μ phase precipitate (2.30), so μ phase could precipitate if there is enough thermo-exposition. In contrast, the calculated EHN is less than that of critical EHN of σ phase precipitate (2.52). However the σ phase is also observed by TEM. Enrich of Cr and Mo around γ phase after γ′phase precipitated leads to σ phase precipitated.
基金The National Natural Science Foundation of China(NSFC-Nos.22138002,22078083,and 21978075)the Hunan Key R&D Program Project(2020NK2015)+2 种基金National Key R&D Projects in Changsha(kh2005018)National Key Research&Development Program-Intergovernmental International Science and Technology Innovation Cooperation Project(2021YFE0112800)the science and technology innovation Program of Hunan Province(2020RC5032)。
文摘Phase change absorbents for CO_(2)are of great interest because they are expected to greatly reduce the heat energy consumption during the regeneration process.Compared with other phase change absorbents,monoethanolamine(MEA)-sulfolane-water is inexpensive and has a fast absorption rate.It is one of the most promising solvents for large-scale industrial applications.Therefore,this study investigates the mass transfer performance of this phase change system in the process of CO_(2)absorption in a packed tower.By comparing the phase change absorbent and the ordinary absorbent,it is concluded that the use of MEA/sulfolane phase change absorbent has significantly improved mass transfer efficiency compared to a single MEA absorbent at the same concentration.In the 4 mol·L^(-1)MEA/5 mol·L^(-1)sulfolane system,the CO_(2)loading of the upper liquid phase after phase separation is almost zero,while the volume of the lower liquid phase sent to the desorption operation is about half of the total volume of the absorbent,which greatly reduces the energy consumption.This study also investigates the influence of operating parameters such as lean CO_(2)loading,gas and liquid flow rates,CO_(2)partial pressure,and temperature on the volumetric mass transfer coefficient(K_(G)α_(V)).The research shows that K_(G)α_(V) increases with increasing liquid flow rate and decreases with the increase of lean CO_(2)loading and CO_(2)partial pressure,while the inert gas flow rate and temperature have little effect on K_(G)α_(V).In addition,based on the principle of phase change absorption,a predictive equation for the K_(G)α_(V) of MEA-sulfolane in the packed tower was established.The K_(G)α_(V) obtained from the experiment is consistent with the model prediction,and the absolute average deviation(AAD)is 7.8%.
基金the financial support from the National High Magnetic Field Laboratory under NSF DMR-0084173
文摘The volume fraction and morphology of the TCP-phase formed in two kinds of Ni- Mo-Cr-Re superalloys under different heat treatment conditions were investigated in this paper. In Re-5% alloy, with increasing of the heat treatment temperature and prolonging the holding time, the volume fraction of TCP-phase decreased and the TCP-phase size increased. At relatively lower temperature, the TCP-phase prefers to present in the dendrite cores. In Re-10% alloy, the volume fraction and size have the same change tendency as that of in Re-5% alloy, but the morphology will change from needle-like and block-like to sphere when the temperature increases. The TCP-phases formed in these two Ni-Mo-Cr-Re alloys are σ and P phase.
基金supported by Jiangsu Science and Technology Department(No.BG2007044)Jiangsu Preventive Medicine Foundation(No.Y2006025).
文摘A rapid and simple preconcentration step applying packed-fiber solid-phase extraction columns has been investigated to vitamin B12. The extraction performance of the new method was investigated preliminarily on vitamin functional drink. The analysis used a reversed-phase C18 column, with a photo-diode array detector at 220 nm. The samples were preconcentrated with packed-fiber solid-phase extraction columns. Good linearity was observed in vitamin functional drink. The repeatability of extraction performance, expressed as relative standard deviations, was from 3.5% to 4.3%. The limit of detection （LOD） is 5 ng mL^-1 （S/N = 3）. Finally, the method had been applied for the determination of vitamin B12 in vitamin functional drink.
基金Supported by the National Natural Science Foundation of China.
文摘Overall dispersed side volumetric mare transfer coeffcieats for protein and amino acids were measured in continuous countercurreat PEG4000/KHP aqueous two-phase systems in a 57 mm I.D. packed extraction column. A model for overall dispersed side volumetric mass transfer coefficients was derived by describing the motion of the drops based upon Navier-Stokes equation combined with the relationship between mass transfer coefficients and the drop velocity. The model provides good predictions and can be successfully used in aqueous two-phase extraction. The awrage relative deviation between calculated values and experimental date ranges from 8% to 14%.
文摘计算机网络发展初期阶段,许多研究机构、计算机厂商和公司都推出了自己的网络系统,然而它们之间没有兼容性可言,也无法相互通信。为了解决网络之间兼容性的问题,国际标准组织ISO(International Standard Organized)于1984提出了开放系统互边参考模型OSI/RM(Open System Interconnection/Reference Model),该模型很快成为了计算机网络体系结构中理论模型。
