Al-substituted barium ferrite powders were synthesized using the sol-gel auto-combustion method according to the molecular formula BaAlxFe12-xO19 （x=0, 0.1, 0.2, 0.3, 0.4, 0.5, 1.0）. Compared with non-substituted ba...Al-substituted barium ferrite powders were synthesized using the sol-gel auto-combustion method according to the molecular formula BaAlxFe12-xO19 （x=0, 0.1, 0.2, 0.3, 0.4, 0.5, 1.0）. Compared with non-substituted barium ferrite annealing at 1000 ℃, the vibrating sample magnetometer （VSM） measurement manifested that the optimum magnetic properties formation temperature of Al-substituted barium ferrite was 1 100 ℃. The data from X-ray diffractometer （XRD） showed that with increasing x, the lattice constants （a and c） decreased as well as the unit-cell volume Vcell. Magnetic measurement of non-substituted and Al-substituted powders annealed from 900 ℃ to 1 200 ℃ exhibited that the maximum magnetization M （10 kOe）, the remanent magnetization Mr and the coercivity Hc depended strongly on the chemical composition of powder as well as the annealing temperature. When annealing at 1 100 ℃, BaAl0.5Fe11.5O19 of high coercivity Hc （6584 Oe） was produced. Meanwhile, M （10 kOe） and Mr were 42.83 emu/g and 25.65 emu/g, respectively.展开更多
Input-output(Leontief)production function is widely used in economic analysis.And diminishing marginal rate of return is a very well accepted economic fact.Leontief production function normally results in a linear pro...Input-output(Leontief)production function is widely used in economic analysis.And diminishing marginal rate of return is a very well accepted economic fact.Leontief production function normally results in a linear production possibility frontier(PPF)due to its linear feature,whereas diminishing marginal rate of return implies a non-linear PPF.In this paper,the authors aim to fix this problem by considering multiple primary inputs in a simplified two-sector economy.The authors find that it is possible to curve a non-linear PPF by using Leontief production function when the authors add heterogeneous primary inputs.The authors also discuss the PPF using non-linear production function.Furthermore,the authors propose that three commonly used economic presumptions cannot hold in the same framework.These presumptions are"single primary input","fixed-proportion inputs"and"law of diminishing marginal returns".展开更多
基金Project supported by the Science Foundation of Shanghai Municipal Commission of Science and Technology （Grant No.0452nm049）
文摘Al-substituted barium ferrite powders were synthesized using the sol-gel auto-combustion method according to the molecular formula BaAlxFe12-xO19 （x=0, 0.1, 0.2, 0.3, 0.4, 0.5, 1.0）. Compared with non-substituted barium ferrite annealing at 1000 ℃, the vibrating sample magnetometer （VSM） measurement manifested that the optimum magnetic properties formation temperature of Al-substituted barium ferrite was 1 100 ℃. The data from X-ray diffractometer （XRD） showed that with increasing x, the lattice constants （a and c） decreased as well as the unit-cell volume Vcell. Magnetic measurement of non-substituted and Al-substituted powders annealed from 900 ℃ to 1 200 ℃ exhibited that the maximum magnetization M （10 kOe）, the remanent magnetization Mr and the coercivity Hc depended strongly on the chemical composition of powder as well as the annealing temperature. When annealing at 1 100 ℃, BaAl0.5Fe11.5O19 of high coercivity Hc （6584 Oe） was produced. Meanwhile, M （10 kOe） and Mr were 42.83 emu/g and 25.65 emu/g, respectively.
基金China Postdoctoral Science Foundation under Grant No.2020M671504the National Social Science Foundation of China under Grant No.14AZD085the National Natural Science Foundation of China under Grant Nos.71373106,71903186。
文摘Input-output(Leontief)production function is widely used in economic analysis.And diminishing marginal rate of return is a very well accepted economic fact.Leontief production function normally results in a linear production possibility frontier(PPF)due to its linear feature,whereas diminishing marginal rate of return implies a non-linear PPF.In this paper,the authors aim to fix this problem by considering multiple primary inputs in a simplified two-sector economy.The authors find that it is possible to curve a non-linear PPF by using Leontief production function when the authors add heterogeneous primary inputs.The authors also discuss the PPF using non-linear production function.Furthermore,the authors propose that three commonly used economic presumptions cannot hold in the same framework.These presumptions are"single primary input","fixed-proportion inputs"and"law of diminishing marginal returns".
