The enthalpies of mixing of L-arginine with 2,2,2-trifluoroethanol and their respective enthalpies of dilu- tion in aqueous solutions at 298.15, 303.15 and 310.15 K were determined as a function of the mole fraction b...The enthalpies of mixing of L-arginine with 2,2,2-trifluoroethanol and their respective enthalpies of dilu- tion in aqueous solutions at 298.15, 303.15 and 310.15 K were determined as a function of the mole fraction by flow microcalorimetric measurement. These experimental results were analyzed to obtain heterotactic enthalpic interaction coeffieients（hxy , hxy , hxy） according to the McMillan-Mayer theory. The hxy coefficients between L-arginine molecule studied and 2,2,2-trifluoroethanol molecule in aqueous solutions at 298.15, 303.15 and 310.15 K were found to be all negative. The results were discussed in terms of solute-solute interaction and solute-solvent interaction.展开更多
The pattern of isentropes in the vicinity of a first-order phase transition is proposed as a key for a sub-classification. While the confinement-deconfinement transition, conjectured to set in beyond a critical end po...The pattern of isentropes in the vicinity of a first-order phase transition is proposed as a key for a sub-classification. While the confinement-deconfinement transition, conjectured to set in beyond a critical end point in the QCD phase diagram, is often related to an entropic transition and the apparently settled gas-liquid transition in nuclear matter is an enthalphic transition, the conceivable local isentropes w.r.t. “incoming” or “outgoing” serve as another useful guide for discussing possible implications, both in the presumed hydrodynamical expansion stage of heavy-ion collisions and the core-collapse of supernova explosions. Examples, such as the quark-meson model and two-phase models, are shown to distinguish concisely the different transitions.展开更多
The studies of the enthalpic interaction parameters, hxy, hxyy and hxxy, of alkali metal halides with glycine, α-alanine and α-aminobutyric acid were published. Synthetic considering of the results of the studies, ...The studies of the enthalpic interaction parameters, hxy, hxyy and hxxy, of alkali metal halides with glycine, α-alanine and α-aminobutyric acid were published. Synthetic considering of the results of the studies, some inter- esting behaviors of the interaction between alkali metal halides and the α-amino acids have been found. The values of hxywill increase with the increase of the number of carbon atoms in alkyl side chain of amino acid molecules and decrease with the increase of the radius of the ions. The increasing of the salt’s effect on the hydrophobic hydration structure as the radii of anion is more obvious than as that of cation. The value of hxxy will regularly decrease with the increase of the number of carbon atoms in the alkyl chain of amino acids and linear increase with the increase of the radius. But the relation of hxxywith the radius of cations is not evident. The value of hxyywill increase with the increase of the radii of the ions. As the increase of the number of carbon atoms of amino acids, hxyyis decreas for the ions which have lager size and there is a maximum value at α-alanine for the ions which have small size. The behaviors of the interaction mentioned above were further discussed in view of electrostatic and structural interac- tions.展开更多
Catenated cages are generally considered thermodynamically more stable than their constituent monomeric cages.However,the catenation mechanism is yet to be elucidated;it would require systematic investigation into the...Catenated cages are generally considered thermodynamically more stable than their constituent monomeric cages.However,the catenation mechanism is yet to be elucidated;it would require systematic investigation into the structural effects of the building blocks,their enthalpic and entropic contributions,and the effect of solvents.By inspecting these factors,we rationalized some design principles for the efficient construction of catenated cages.展开更多
The segregation of Sn and discontinuous precipitation at grain boundaries are detrimental to the strength,ductility,and machinability of the Cu−Ni−Sn alloy.A strategy to solve the above problems is multi-component com...The segregation of Sn and discontinuous precipitation at grain boundaries are detrimental to the strength,ductility,and machinability of the Cu−Ni−Sn alloy.A strategy to solve the above problems is multi-component composition design by introducing strong enthalpic interaction element.In this work,a series of Cu_(80)Ni_(15)Sn_(5−x)Ti_(x)(at.%)alloys were designed by cluster-plus-glue-atom model,and the effects of Ti content on the microstructure and properties of the alloys were systematically investigated using TEM and other analysis methods.The results demonstrate that Ti can effectively inhibit the segregation and discontinuous precipitation while promoting continuous precipitation to improve the high-temperature stability of the alloys.As the Ti content increases,the distribution of Ti changes from uniform distribution to predominant precipitation.The hardness and conductivity of the alloy exceed those of the C72900(Cu−15Ni−8Sn(wt.%))commercial alloy and the Cu_(80)Ni_(15)Sn_(5)(at.%)reference alloy when Ti is in the solution state.展开更多
基金Supported by the Natural Scientific Foundation of Shandong Province, China(NoZ2007B03)the Doctoral Fund of the Ministry of Education of China(New Teachers Fund)(No070422047)
文摘The enthalpies of mixing of L-arginine with 2,2,2-trifluoroethanol and their respective enthalpies of dilu- tion in aqueous solutions at 298.15, 303.15 and 310.15 K were determined as a function of the mole fraction by flow microcalorimetric measurement. These experimental results were analyzed to obtain heterotactic enthalpic interaction coeffieients（hxy , hxy , hxy） according to the McMillan-Mayer theory. The hxy coefficients between L-arginine molecule studied and 2,2,2-trifluoroethanol molecule in aqueous solutions at 298.15, 303.15 and 310.15 K were found to be all negative. The results were discussed in terms of solute-solute interaction and solute-solvent interaction.
文摘The pattern of isentropes in the vicinity of a first-order phase transition is proposed as a key for a sub-classification. While the confinement-deconfinement transition, conjectured to set in beyond a critical end point in the QCD phase diagram, is often related to an entropic transition and the apparently settled gas-liquid transition in nuclear matter is an enthalphic transition, the conceivable local isentropes w.r.t. “incoming” or “outgoing” serve as another useful guide for discussing possible implications, both in the presumed hydrodynamical expansion stage of heavy-ion collisions and the core-collapse of supernova explosions. Examples, such as the quark-meson model and two-phase models, are shown to distinguish concisely the different transitions.
基金Project supported by the National Natural Science Foundation of China (No. 29773011) and the Education Department of Henan Province (No.20011500012).
文摘The studies of the enthalpic interaction parameters, hxy, hxyy and hxxy, of alkali metal halides with glycine, α-alanine and α-aminobutyric acid were published. Synthetic considering of the results of the studies, some inter- esting behaviors of the interaction between alkali metal halides and the α-amino acids have been found. The values of hxywill increase with the increase of the number of carbon atoms in alkyl side chain of amino acid molecules and decrease with the increase of the radius of the ions. The increasing of the salt’s effect on the hydrophobic hydration structure as the radii of anion is more obvious than as that of cation. The value of hxxy will regularly decrease with the increase of the number of carbon atoms in the alkyl chain of amino acids and linear increase with the increase of the radius. But the relation of hxxywith the radius of cations is not evident. The value of hxyywill increase with the increase of the radii of the ions. As the increase of the number of carbon atoms of amino acids, hxyyis decreas for the ions which have lager size and there is a maximum value at α-alanine for the ions which have small size. The behaviors of the interaction mentioned above were further discussed in view of electrostatic and structural interac- tions.
基金supported by the National Natural Science Foundation of China(key program 21890733)and the Shanghai Natural Science Foundation(no.18ZR1420800).
文摘Catenated cages are generally considered thermodynamically more stable than their constituent monomeric cages.However,the catenation mechanism is yet to be elucidated;it would require systematic investigation into the structural effects of the building blocks,their enthalpic and entropic contributions,and the effect of solvents.By inspecting these factors,we rationalized some design principles for the efficient construction of catenated cages.
基金support from the National Natural Science Foundation of China(No.52071052).
文摘The segregation of Sn and discontinuous precipitation at grain boundaries are detrimental to the strength,ductility,and machinability of the Cu−Ni−Sn alloy.A strategy to solve the above problems is multi-component composition design by introducing strong enthalpic interaction element.In this work,a series of Cu_(80)Ni_(15)Sn_(5−x)Ti_(x)(at.%)alloys were designed by cluster-plus-glue-atom model,and the effects of Ti content on the microstructure and properties of the alloys were systematically investigated using TEM and other analysis methods.The results demonstrate that Ti can effectively inhibit the segregation and discontinuous precipitation while promoting continuous precipitation to improve the high-temperature stability of the alloys.As the Ti content increases,the distribution of Ti changes from uniform distribution to predominant precipitation.The hardness and conductivity of the alloy exceed those of the C72900(Cu−15Ni−8Sn(wt.%))commercial alloy and the Cu_(80)Ni_(15)Sn_(5)(at.%)reference alloy when Ti is in the solution state.
