本文提出了将试剂 N-烯丙基-N′-(对苯磺酸钠)硫脲用于Bi(Ⅲ)-Cu(Ⅱ)-NTu-I(?)异金属四元体系中,光度测定微量 Bi 的新方法.实验结果表明:该法显色快、稳定性好、选择性高,优于经典的碘化物法和硫脲法.在水相中可直接测定,操作简单.铋...本文提出了将试剂 N-烯丙基-N′-(对苯磺酸钠)硫脲用于Bi(Ⅲ)-Cu(Ⅱ)-NTu-I(?)异金属四元体系中,光度测定微量 Bi 的新方法.实验结果表明:该法显色快、稳定性好、选择性高,优于经典的碘化物法和硫脲法.在水相中可直接测定,操作简单.铋浓度在0～110μg/mL 范围内成直线关系,ε≈1×10~4. 对回收实验和合成样品分析,均获得满意的结果.展开更多
In this paper, the definition of weak dominance is proposed for a NTU game and two new solution concepts of NTU games are introduced: the refined core and weakly stable set. The relationship is explored among the core...In this paper, the definition of weak dominance is proposed for a NTU game and two new solution concepts of NTU games are introduced: the refined core and weakly stable set. The relationship is explored among the core, the weakly stable set and the refined core.展开更多
This work aims to establish comparisons between two models used for the performance of heat exchangers. The chosen system, in this case, consists of a heat exchanger used in automotive radiators flat finned tube type....This work aims to establish comparisons between two models used for the performance of heat exchangers. The chosen system, in this case, consists of a heat exchanger used in automotive radiators flat finned tube type. Water and ethylene glycol compound as base fluid and volume fractions of iron oxide nanoparticles (Fe<sub>3</sub>O<sub>4</sub>) are used as a refrigerant. The quantities determined in this work are the nanofluid exit temperature, the air exit temperature, the absolute error between the models for heat transfer rate, and Effectiveness. The quantities that constitute parameters, independent variables, are the airflow, represented by the Reynolds number, and the iron oxide volume fraction. Ethylene Glycol 50% compound has slightly better thermal performance than pure water and reduces the reactive effect of water on the environment, increasing the average life of the equipment. The absolute relative error between the models is less than 20% and presents maximum values with the increase of the nanoparticle volume fraction and growth in the Reynolds number for the air.展开更多
文摘In this paper, the definition of weak dominance is proposed for a NTU game and two new solution concepts of NTU games are introduced: the refined core and weakly stable set. The relationship is explored among the core, the weakly stable set and the refined core.
文摘This work aims to establish comparisons between two models used for the performance of heat exchangers. The chosen system, in this case, consists of a heat exchanger used in automotive radiators flat finned tube type. Water and ethylene glycol compound as base fluid and volume fractions of iron oxide nanoparticles (Fe<sub>3</sub>O<sub>4</sub>) are used as a refrigerant. The quantities determined in this work are the nanofluid exit temperature, the air exit temperature, the absolute error between the models for heat transfer rate, and Effectiveness. The quantities that constitute parameters, independent variables, are the airflow, represented by the Reynolds number, and the iron oxide volume fraction. Ethylene Glycol 50% compound has slightly better thermal performance than pure water and reduces the reactive effect of water on the environment, increasing the average life of the equipment. The absolute relative error between the models is less than 20% and presents maximum values with the increase of the nanoparticle volume fraction and growth in the Reynolds number for the air.
