The zero-strain spinel Li_(4)Ti_(5)O_(12)stands out as a promising anode material for lithium-ion batteries due to its outstanding cycling stability.However,the limited theoretic specific capacity,low Li^(+) diffusion...The zero-strain spinel Li_(4)Ti_(5)O_(12)stands out as a promising anode material for lithium-ion batteries due to its outstanding cycling stability.However,the limited theoretic specific capacity,low Li^(+) diffusion coefficient and electronic conductivity severely hinder its practical application.In this study,we demonstrate a strategy of introducing abundant oxygen vacancies not only on the surface and but also inside the bulk of Li_(4)Ti_(5)O_(12)particles via reductive thermal sintering.The oxygen vacancies can significantly enhance the electronic conductivity and lithium-ion diffusion coefficient of Li_(4)Ti_(5)O_(12),leading to a remarkable improvement in rate performance and a reduction in polarization.Moreover,additional lithium-ion accommodation sites can be created at the defective surface,contributing to a high specific capacity of over 200 mAh g^(-1).展开更多
Six years have passed since the global financial crisis began.Yet,mainstream economists are still far from reaching a consensus on a framework for restructuring macroeconomic policy.In April 2013,many top scholars att...Six years have passed since the global financial crisis began.Yet,mainstream economists are still far from reaching a consensus on a framework for restructuring macroeconomic policy.In April 2013,many top scholars attended the International Monetary Fund's(IMF) second conference on "Rethinking Macro Policy".During the conference,the following basic assessments with respect to macroeconomic policy were reached:economists and policy-makers have entered a "brave new world" where they face more problems than effective solutions and the image of a new macroeconomic policy framework remains opaque.Based on discussions at the conference and the dissertations of important scholars over recent years,this paper provides a systematic review of the reflections of mainstream economic academia regarding the restructuring of a macroeconomic policy framework,with a view to providing an orientation to China s ongoing reform of macroeconomic regulation.展开更多
Bulk mineral resources of iron ores, copper ores, bauxite, lead ores, zinc ores and potassium salt play a pivotal role on the world＇s and China＇s economic development. This study analyzed and predicted their resourc...Bulk mineral resources of iron ores, copper ores, bauxite, lead ores, zinc ores and potassium salt play a pivotal role on the world＇s and China＇s economic development. This study analyzed and predicted their resources base and potential, development and utilization and their world＇s and China＇s supply and demand situation in the future 20 years. The supply and demand of these six bulk mineral products are generally balanced, with a slight surplus, which will guarantee the stability of the international mineral commodity market supply. The six mineral resources （especially iron ores and copper ores） are abundant and have a great potential, and their development and utilization scale will gradually increase. Till the end of 2014, the reserve- production ratio of iron, copper, bauxite, lead, zinc ores and potassium salt was 95 years, 42 years, 100 years, 17 years, 37 years and 170 years, respectively. Except lead ores, the other five types all have reserve-production ratio exceeding 20 years, indicative of a high resources guarantee degree. If the utilization of recycled metals is counted in, the supply of the world＇s six mineral products will exceed the demand in the future twenty years. In 2015-2035, the supply of iron ores, refined copper, primary aluminum, refined lead, zinc and potassium salt will exceed their demand by 0.4-0.7 billion tons （Gt）, 5.0-6.0 million tons （Mt）, 1.1-8.9 Mt, 1.0-2.0 Mt, 1.2-2.0 Mt and 4.8-5.6 Mt, respectively. It is predicted that there is no problem with the supply side of bulk mineral products such as iron ores, but local or structural shortage may occur because of geopolitics, monopoly control, resources nationalism and trade friction. Affected by China＇s compressed industrialized development model, the demand of iron ores （crude steel）, potassium salt, refined lead, refined copper, bauxite （primary aluminum） and zinc will gradually reach their peak in advance. The demand peak of iron ores （crude steel） will reach around 2015, 2016 for potassium salt, 2020 for refined lead, 2021 for bauxite （primary aluminum）, 2022 for refined copper and 2023 for zinc. China＇s demand for iron ores （crude steel）, bauxite （primary aluminum） and zinc in the future 20 years will decline among the world＇s demand, while that for refined copper, refined lead and potassium salt will slightly increase. The demand for bulk mineral products still remains high. In 2015-2035, China＇s accumulative demand for iron ores （crude steel） will be 20.313 Gt （13.429 Gt）, 0.304 Gt for refined copper, 2.466 Gt （0.616 Gt） of bauxite （primary aluminum）, 0.102 Gt of refined lead, 0.138 Gt of zinc and 0.157 Gt of potassium salt, and they account for the world＇s YOY （YOY） accumulative demand of 35.17%, 51.09%, 48.47%, 46.62%, 43.95% and 21.84%, respectively. This proportion is 49.40%, 102.52%, 87.44%, 105.65%, 93.62% and 106.49% of that in 2014, respectively. From the supply side of China＇s bulk mineral resources, it is forecasted that the accumulative supply of primary （mine） mineral products in 2015-2035 is 4.046 Gt of iron ores, 0.591 Gt of copper, 1.129 Gt of bauxite, 63.661 Mt of （mine） lead, 0.109 Gt of （mine） zinc and 0.128 Gt of potassium salt, which accounts for 8.82%, 13.92%, 26.67%, 47.09%, 33.04% and 15.56% of the world＇s predicted YOY production, respectively. With the rapid increase in the smelting capacity of iron and steel and alumina, the rate of capacity utilization for crude steel, refined copper, alumina, primary aluminum and refined lead in 2014 was 72.13%, 83.63%, 74.45%, 70.76% and 72.22%, respectively. During 2000-2014, the rate of capacity utilization for China＇s crude steel and refined copper showed a generally fluctuating decrease, which leads to an insufficient supply of primary mineral products. It is forecasted that the supply insufficiency of iron ores in 2015-2035 is 17.44 Gt, 0.245 Gt of copper in copper concentrates, 1.337 Gt of bauxite, 38.44 Mt of lead in lead concentrates and 29.19 Mt of zinc in zinc concentrates. China has gradually raised the utilization of recycled metals, which has mitigated the insufficient supply of primary metal products to some extent. It is forecasted that in 2015-2035 the accumulative utilization amount of steel scrap （iron ores） is 3.27 Gt （5.08 Gt）, 70.312 Mt of recycled copper, 0.2 Gt of recycled aluminum, 48 Mt of recycled lead and 7.7 Mt of recycled zinc. The analysis on the supply and demand situation of China＇s bulk mineral resources in 2015-2035 suggests that the supply-demand contradiction for these six types of mineral products will decrease, indicative of a generally declining external dependency. If the use of recycled metal amount is counted in, the external dependency of China＇s iron, copper, bauxite, lead, zinc and potassium salt will be 79%, 65%, 26%, 8%, 16% and 18% in 2014, respectively. It is predicted that this external dependency will decrease to 62%, 64%, 20%, -0.93%, 16% and 14% in 2020, respectively, showing an overall decreasing trend. We propose the following suggestions correspondingly. （1） The demand peak of China＇s crude steel and potassium salt will reach during 2015-2023 in succession. Mining transformation should be planned and deployed in advance to deal with the arrival of this demand peak. （2） The supply-demand contradiction of China＇s bulk mineral resources will mitigate in the future 20 years, and the external dependency will decrease accordingly. It is suggested to adjust the mineral resources management policies according to different minerals and regions, and regulate the exploration and development activities. （3） China should further establish and improve the forced mechanism of resolving the smelting overcapacity of steel, refined copper, primary aluminum, lead and zinc to really achieve the goal of ＂reducing excess production capacity＂. （4） In accordance with the national strategic deployment of ＂One Belt One Road＂, China should encourage the excess capacity of steel, copper, alumina and primary aluminum enterprises to transfer to those countries or areas with abundant resources, high energy matching degree and relatively excellent infrastructure. Based on the national conditions, mining condition and geopolitics of the resources countries, we will gradually build steel, copper, aluminum and lead-zinc smelting bases, and potash processing and production bases, which will promote the excess capacity to transfer to the overseas orderly. （5） It is proposed to strengthen the planning and management of renewable resources recycling and to construct industrial base of renewable metal recycling. （6） China should promote the comprehensive development and utilization of paragenetic and associated mineral species to further improve the comprehensive utilization of bulk mineral resources.展开更多
Based on the stoichiometric method and the free energy minimization method,an ideal model for the reduction of iron oxides by carbon and hydrogen under blast furnace conditions was established,and the reduction effici...Based on the stoichiometric method and the free energy minimization method,an ideal model for the reduction of iron oxides by carbon and hydrogen under blast furnace conditions was established,and the reduction efficiency and theoretical energy consumption of the all-carbon blast furnace and the hydrogen-rich blast furnace were compared.The results show that after the reduction reaction is completed at the bottom of the blast furnace,the gas produced by reduction at 1600℃still has a certain excessive reduction capacity,which is due to the hydrogen brought in by the hydrogen-rich blast as well as the excess carbon monoxide generated by the reaction of the coke and the oxygen brought in by the blast.During the process of the gas with excessive reduction capacity rising from the bottom of the blast furnace and gas reduction process,the excessive reduction capacity of the gas gradually decreases with the increase in the dydrogen content in the blast.In the all-carbon blast furnace,the excess gas reduction capacity is the strongest,and the total energy consumption per ton of iron reduction is the lowest.This shows that,for the current operation mode of the blast furnace,adding hydrogen in the blast furnace cannot reduce the consumption of carbon required for reduction per ton of iron,but rather increases the consumption of carbon.展开更多
Excess heat capacities at glass transition temperature in two types of glass-forming systems of [xNaNO3(1x)KNO3]60·[Ca(NO3)2]40(0x1) and Ca(NO3)2yH2O(4y13) are studied.In the former system,with the replacement of...Excess heat capacities at glass transition temperature in two types of glass-forming systems of [xNaNO3(1x)KNO3]60·[Ca(NO3)2]40(0x1) and Ca(NO3)2yH2O(4y13) are studied.In the former system,with the replacement of K + cation with Na + cation,the excess heat capacity is around 65.1 J mol-1·K-1,while the excess increases by 38.9 J mol-1·K-1 upon one molar H2O content in latter system.A quantitative description to the excess heat capacity is built up with the thermal effects of atomic and molecular translational motion in liquids.The results might offer a further understanding to the glass transition.展开更多
In order to improve the calculation method of the isosteric adsorption heat,clarify thermodynamic characteristics of CH4 adsorption by continental shale and reveal the adsorption mechanism,this paper selected shale sa...In order to improve the calculation method of the isosteric adsorption heat,clarify thermodynamic characteristics of CH4 adsorption by continental shale and reveal the adsorption mechanism,this paper selected shale samples from the seventh Member of Yanchang Formation of Upper Triassic in the Yanchang Gasfield of the Ordos Basin as the research object.The isothermal adsorption experiment was carried out on the CH4 adsorption by continental shale and the excess adsorption curves were plotted.Then,the characteristics of the isosteric adsorption heat of the shale with different types of adsorption capacity were illustrated by analyzing and comparing the difference between excess and absolute adsorption capacity.And the following research results were obtained.First,under the same temperature and pressure,absolute adsorption capacity is higher than the excess values.The difference between them is higher under low temperature and high pressure and it is in the relationship of exponential function with the equilibrium pressure.If excess adsorption capacity is used to evaluate the adsorptive property of shale reservoirs,the evaluation result will be underestimated.Second,for CH4 adsorption by Yanchang Formation shale,the absolute and excess isosteric adsorption heat values have a linear positive correlation with absolute and excess adsorption capacity respectively,and the intermo-lecular force of adsorbate has a dominant effect on isosteric adsorption heat values.Third,absolute isosteric adsorption heat value is less than the excess heat.The relative error is in the range of 18.18e49.79%,and it is higher in the stage with low adsorption capacity.If excess adsorption capacity is taken as the basic data to calculate initial isosteric adsorption heat values,the calculation result will be overvalued,and consequently,the evaluation of the intermolecular force of adsorbent and adsorbate is overestimated.展开更多
Molar heat capacities of n-butanol and the azeotropic mixture in the binary system [water （x=0.716） plus n-butanol （x=0.284）] were measured with an adiabatic calorimeter in a temperature range from 78 to 320 K. Th...Molar heat capacities of n-butanol and the azeotropic mixture in the binary system [water （x=0.716） plus n-butanol （x=0.284）] were measured with an adiabatic calorimeter in a temperature range from 78 to 320 K. The functions of the heat capacity with respect to thermodynamic temperature were estabhshed for the azeotropic mixture. A glass transition was observed at （111.9±1.2） K. The phase transitions took place at （179.26±0.77） and （269.69±0.14） K corresponding to the solid-hquid phase transitions of n-butanol and water, respectively. The phase-transition enthalpy and entropy of water were calculated. A thermodynamic function of excess molar heat capacity with respect to temperature was estabhshed, which took account of physical mixing, destructions of self-association and cross-association for n-butanol and water, respectively. The thermodynamic functions and the excess thermodynamic ones of the binary systems relative to 298.15 K were derived based on the relationships of the thermodynamic functions and the function of the measured heat capacity and the calculated excess heat capacity with respect to temperature.展开更多
基金supported by the National Natural Science Foundation of China(No.52102200)the Major Science and Technology Infrastructure Project of Material Genome Big-science Facilities Platform supported by Municipal Development and Reform Commission of Shenzhen,Basic and Applied Basic Research Foundation of Guangdong Province(No.2021B1515130002)+1 种基金International Joint Research Center for Electric Vehicle Power Battery and Materials(No.2015B01015)Guangdong Key Laboratory of Design and Calculation of New Energy Materials(No.2017B030301013).
文摘The zero-strain spinel Li_(4)Ti_(5)O_(12)stands out as a promising anode material for lithium-ion batteries due to its outstanding cycling stability.However,the limited theoretic specific capacity,low Li^(+) diffusion coefficient and electronic conductivity severely hinder its practical application.In this study,we demonstrate a strategy of introducing abundant oxygen vacancies not only on the surface and but also inside the bulk of Li_(4)Ti_(5)O_(12)particles via reductive thermal sintering.The oxygen vacancies can significantly enhance the electronic conductivity and lithium-ion diffusion coefficient of Li_(4)Ti_(5)O_(12),leading to a remarkable improvement in rate performance and a reduction in polarization.Moreover,additional lithium-ion accommodation sites can be created at the defective surface,contributing to a high specific capacity of over 200 mAh g^(-1).
文摘Six years have passed since the global financial crisis began.Yet,mainstream economists are still far from reaching a consensus on a framework for restructuring macroeconomic policy.In April 2013,many top scholars attended the International Monetary Fund's(IMF) second conference on "Rethinking Macro Policy".During the conference,the following basic assessments with respect to macroeconomic policy were reached:economists and policy-makers have entered a "brave new world" where they face more problems than effective solutions and the image of a new macroeconomic policy framework remains opaque.Based on discussions at the conference and the dissertations of important scholars over recent years,this paper provides a systematic review of the reflections of mainstream economic academia regarding the restructuring of a macroeconomic policy framework,with a view to providing an orientation to China s ongoing reform of macroeconomic regulation.
基金supported by the China geological survey subproject of Dynamic Track and Evaluation of the Guarantee Degree of the Main Mineral Resources in China(No.121201103000150112,N1618-8)
文摘Bulk mineral resources of iron ores, copper ores, bauxite, lead ores, zinc ores and potassium salt play a pivotal role on the world＇s and China＇s economic development. This study analyzed and predicted their resources base and potential, development and utilization and their world＇s and China＇s supply and demand situation in the future 20 years. The supply and demand of these six bulk mineral products are generally balanced, with a slight surplus, which will guarantee the stability of the international mineral commodity market supply. The six mineral resources （especially iron ores and copper ores） are abundant and have a great potential, and their development and utilization scale will gradually increase. Till the end of 2014, the reserve- production ratio of iron, copper, bauxite, lead, zinc ores and potassium salt was 95 years, 42 years, 100 years, 17 years, 37 years and 170 years, respectively. Except lead ores, the other five types all have reserve-production ratio exceeding 20 years, indicative of a high resources guarantee degree. If the utilization of recycled metals is counted in, the supply of the world＇s six mineral products will exceed the demand in the future twenty years. In 2015-2035, the supply of iron ores, refined copper, primary aluminum, refined lead, zinc and potassium salt will exceed their demand by 0.4-0.7 billion tons （Gt）, 5.0-6.0 million tons （Mt）, 1.1-8.9 Mt, 1.0-2.0 Mt, 1.2-2.0 Mt and 4.8-5.6 Mt, respectively. It is predicted that there is no problem with the supply side of bulk mineral products such as iron ores, but local or structural shortage may occur because of geopolitics, monopoly control, resources nationalism and trade friction. Affected by China＇s compressed industrialized development model, the demand of iron ores （crude steel）, potassium salt, refined lead, refined copper, bauxite （primary aluminum） and zinc will gradually reach their peak in advance. The demand peak of iron ores （crude steel） will reach around 2015, 2016 for potassium salt, 2020 for refined lead, 2021 for bauxite （primary aluminum）, 2022 for refined copper and 2023 for zinc. China＇s demand for iron ores （crude steel）, bauxite （primary aluminum） and zinc in the future 20 years will decline among the world＇s demand, while that for refined copper, refined lead and potassium salt will slightly increase. The demand for bulk mineral products still remains high. In 2015-2035, China＇s accumulative demand for iron ores （crude steel） will be 20.313 Gt （13.429 Gt）, 0.304 Gt for refined copper, 2.466 Gt （0.616 Gt） of bauxite （primary aluminum）, 0.102 Gt of refined lead, 0.138 Gt of zinc and 0.157 Gt of potassium salt, and they account for the world＇s YOY （YOY） accumulative demand of 35.17%, 51.09%, 48.47%, 46.62%, 43.95% and 21.84%, respectively. This proportion is 49.40%, 102.52%, 87.44%, 105.65%, 93.62% and 106.49% of that in 2014, respectively. From the supply side of China＇s bulk mineral resources, it is forecasted that the accumulative supply of primary （mine） mineral products in 2015-2035 is 4.046 Gt of iron ores, 0.591 Gt of copper, 1.129 Gt of bauxite, 63.661 Mt of （mine） lead, 0.109 Gt of （mine） zinc and 0.128 Gt of potassium salt, which accounts for 8.82%, 13.92%, 26.67%, 47.09%, 33.04% and 15.56% of the world＇s predicted YOY production, respectively. With the rapid increase in the smelting capacity of iron and steel and alumina, the rate of capacity utilization for crude steel, refined copper, alumina, primary aluminum and refined lead in 2014 was 72.13%, 83.63%, 74.45%, 70.76% and 72.22%, respectively. During 2000-2014, the rate of capacity utilization for China＇s crude steel and refined copper showed a generally fluctuating decrease, which leads to an insufficient supply of primary mineral products. It is forecasted that the supply insufficiency of iron ores in 2015-2035 is 17.44 Gt, 0.245 Gt of copper in copper concentrates, 1.337 Gt of bauxite, 38.44 Mt of lead in lead concentrates and 29.19 Mt of zinc in zinc concentrates. China has gradually raised the utilization of recycled metals, which has mitigated the insufficient supply of primary metal products to some extent. It is forecasted that in 2015-2035 the accumulative utilization amount of steel scrap （iron ores） is 3.27 Gt （5.08 Gt）, 70.312 Mt of recycled copper, 0.2 Gt of recycled aluminum, 48 Mt of recycled lead and 7.7 Mt of recycled zinc. The analysis on the supply and demand situation of China＇s bulk mineral resources in 2015-2035 suggests that the supply-demand contradiction for these six types of mineral products will decrease, indicative of a generally declining external dependency. If the use of recycled metal amount is counted in, the external dependency of China＇s iron, copper, bauxite, lead, zinc and potassium salt will be 79%, 65%, 26%, 8%, 16% and 18% in 2014, respectively. It is predicted that this external dependency will decrease to 62%, 64%, 20%, -0.93%, 16% and 14% in 2020, respectively, showing an overall decreasing trend. We propose the following suggestions correspondingly. （1） The demand peak of China＇s crude steel and potassium salt will reach during 2015-2023 in succession. Mining transformation should be planned and deployed in advance to deal with the arrival of this demand peak. （2） The supply-demand contradiction of China＇s bulk mineral resources will mitigate in the future 20 years, and the external dependency will decrease accordingly. It is suggested to adjust the mineral resources management policies according to different minerals and regions, and regulate the exploration and development activities. （3） China should further establish and improve the forced mechanism of resolving the smelting overcapacity of steel, refined copper, primary aluminum, lead and zinc to really achieve the goal of ＂reducing excess production capacity＂. （4） In accordance with the national strategic deployment of ＂One Belt One Road＂, China should encourage the excess capacity of steel, copper, alumina and primary aluminum enterprises to transfer to those countries or areas with abundant resources, high energy matching degree and relatively excellent infrastructure. Based on the national conditions, mining condition and geopolitics of the resources countries, we will gradually build steel, copper, aluminum and lead-zinc smelting bases, and potash processing and production bases, which will promote the excess capacity to transfer to the overseas orderly. （5） It is proposed to strengthen the planning and management of renewable resources recycling and to construct industrial base of renewable metal recycling. （6） China should promote the comprehensive development and utilization of paragenetic and associated mineral species to further improve the comprehensive utilization of bulk mineral resources.
基金The author are thankful for the support from the National Natural Science Foundation of China(Nos.U1560203,51704021,and 51274031)Beijing Key Laboratory of Special Melting and Preparation of High-End Metal Materials.
文摘Based on the stoichiometric method and the free energy minimization method,an ideal model for the reduction of iron oxides by carbon and hydrogen under blast furnace conditions was established,and the reduction efficiency and theoretical energy consumption of the all-carbon blast furnace and the hydrogen-rich blast furnace were compared.The results show that after the reduction reaction is completed at the bottom of the blast furnace,the gas produced by reduction at 1600℃still has a certain excessive reduction capacity,which is due to the hydrogen brought in by the hydrogen-rich blast as well as the excess carbon monoxide generated by the reaction of the coke and the oxygen brought in by the blast.During the process of the gas with excessive reduction capacity rising from the bottom of the blast furnace and gas reduction process,the excessive reduction capacity of the gas gradually decreases with the increase in the dydrogen content in the blast.In the all-carbon blast furnace,the excess gas reduction capacity is the strongest,and the total energy consumption per ton of iron reduction is the lowest.This shows that,for the current operation mode of the blast furnace,adding hydrogen in the blast furnace cannot reduce the consumption of carbon required for reduction per ton of iron,but rather increases the consumption of carbon.
基金supported by the National Natural Science Foundation of China (Grant Nos. 51071170 and 11274353)the National Basic Research Program of China (Grant Nos. 2007CB613904 and 2010CB-731603)
文摘Excess heat capacities at glass transition temperature in two types of glass-forming systems of [xNaNO3(1x)KNO3]60·[Ca(NO3)2]40(0x1) and Ca(NO3)2yH2O(4y13) are studied.In the former system,with the replacement of K + cation with Na + cation,the excess heat capacity is around 65.1 J mol-1·K-1,while the excess increases by 38.9 J mol-1·K-1 upon one molar H2O content in latter system.A quantitative description to the excess heat capacity is built up with the thermal effects of atomic and molecular translational motion in liquids.The results might offer a further understanding to the glass transition.
基金supported by the National Major Science and Technology Project"Key Technologies for Exploration and Development of Continental Shale Gas in Yan'an"(No.2017ZX05039001005).
文摘In order to improve the calculation method of the isosteric adsorption heat,clarify thermodynamic characteristics of CH4 adsorption by continental shale and reveal the adsorption mechanism,this paper selected shale samples from the seventh Member of Yanchang Formation of Upper Triassic in the Yanchang Gasfield of the Ordos Basin as the research object.The isothermal adsorption experiment was carried out on the CH4 adsorption by continental shale and the excess adsorption curves were plotted.Then,the characteristics of the isosteric adsorption heat of the shale with different types of adsorption capacity were illustrated by analyzing and comparing the difference between excess and absolute adsorption capacity.And the following research results were obtained.First,under the same temperature and pressure,absolute adsorption capacity is higher than the excess values.The difference between them is higher under low temperature and high pressure and it is in the relationship of exponential function with the equilibrium pressure.If excess adsorption capacity is used to evaluate the adsorptive property of shale reservoirs,the evaluation result will be underestimated.Second,for CH4 adsorption by Yanchang Formation shale,the absolute and excess isosteric adsorption heat values have a linear positive correlation with absolute and excess adsorption capacity respectively,and the intermo-lecular force of adsorbate has a dominant effect on isosteric adsorption heat values.Third,absolute isosteric adsorption heat value is less than the excess heat.The relative error is in the range of 18.18e49.79%,and it is higher in the stage with low adsorption capacity.If excess adsorption capacity is taken as the basic data to calculate initial isosteric adsorption heat values,the calculation result will be overvalued,and consequently,the evaluation of the intermolecular force of adsorbent and adsorbate is overestimated.
基金Project supported by the National Natural Science Foundation of China （No. 20073047） and Doctorial Foundation of Shandong Province （No. 2004BS04021）.
文摘Molar heat capacities of n-butanol and the azeotropic mixture in the binary system [water （x=0.716） plus n-butanol （x=0.284）] were measured with an adiabatic calorimeter in a temperature range from 78 to 320 K. The functions of the heat capacity with respect to thermodynamic temperature were estabhshed for the azeotropic mixture. A glass transition was observed at （111.9±1.2） K. The phase transitions took place at （179.26±0.77） and （269.69±0.14） K corresponding to the solid-hquid phase transitions of n-butanol and water, respectively. The phase-transition enthalpy and entropy of water were calculated. A thermodynamic function of excess molar heat capacity with respect to temperature was estabhshed, which took account of physical mixing, destructions of self-association and cross-association for n-butanol and water, respectively. The thermodynamic functions and the excess thermodynamic ones of the binary systems relative to 298.15 K were derived based on the relationships of the thermodynamic functions and the function of the measured heat capacity and the calculated excess heat capacity with respect to temperature.
