A kind of fine and quasi-spherical Y2O3:Eu3+ phosphor was prepared by firing a preparative precursor at 1 200 ℃ for 2 h with the molten salts of Na2CO3, S and NaCl. The precursor was obtained by homogeneous precipita...A kind of fine and quasi-spherical Y2O3:Eu3+ phosphor was prepared by firing a preparative precursor at 1 200 ℃ for 2 h with the molten salts of Na2CO3, S and NaCl. The precursor was obtained by homogeneous precipitation of yttrium and europium with oxalic acid when using EDTA, citric acid or starch as complexant. The structure and morphology of the phosphors were characterized by XRD and SEM, respectively. The influence of complexing environment, firing temperature and molten salts on formation of the phosphor Y2O3:Eu3+ was discussed. The result show that the prepared Y2O3:Eu3+ phosphor is of quasi-spherical structure with size of 2-3 μm. Its luminescent intensity is 30% higher than that of the same phosphor prepared by the same procedure but without molten salts, and is 5% higher than that of commercial Y2O3:Eu3+ red phosphor.展开更多
Bocs, which is the abbreviated form of bimodule over a categary with coalgebra structure, was introduced by Kleiner and Rojter in 1975 and developed by Drozd in 1979, then formulated by Crawley-Boevey in 1988. Let k b...Bocs, which is the abbreviated form of bimodule over a categary with coalgebra structure, was introduced by Kleiner and Rojter in 1975 and developed by Drozd in 1979, then formulated by Crawley-Boevey in 1988. Let k be an algebraically closed field, A a finitely dimensional k-algebra. Then there exists a bocs B over k associated to A. From this relation Drozd proved one of the most important theorems in representation theory of algebra, namely, a finitely dimensional k-algebra is either of representation tame type or of representation wild type,展开更多
This paper constructs the probability model of the multi-valued KM_1M_2 clock controlled generator,and discusses the probability distributing,homogeneous Markov property,ergodic property,strict placidity,numeral chara...This paper constructs the probability model of the multi-valued KM_1M_2 clock controlled generator,and discusses the probability distributing,homogeneous Markov property,ergodic property,strict placidity,numeral character and the property of large numbers of the random variables with this kind of output sequence.It gets the probability formula of the coincidence of the output sequence with the input sequence,and gives important reference to the design and analysis of the multi-valued key stream clock controlled generator in cryptography.展开更多
通过建立含有类似锥板流变仪结构的实验平台对不同的温度、压力、剪切速率以及CO2质量分数等工艺条件下聚苯乙烯(PS)/超临界CO2(ScCO2)均相体的流变性能展开研究。结果表明:压力的升高会增加均相体的黏度,压力由7.5 MPa升高到10.5 MPa时...通过建立含有类似锥板流变仪结构的实验平台对不同的温度、压力、剪切速率以及CO2质量分数等工艺条件下聚苯乙烯(PS)/超临界CO2(ScCO2)均相体的流变性能展开研究。结果表明:压力的升高会增加均相体的黏度,压力由7.5 MPa升高到10.5 MPa时,CO2质量分数为0.5%的均相体黏度增加了140 Pa s,约为原来的4.6%;增加温度则会降低均相体黏度,而且随着温度的升高,黏度的下降趋势在逐渐减小,温度从443.15 K逐渐增加到473.15 K时,CO2质量分数为0.5%的均相体黏度的减少值分别为778,482,327 Pa s;当均相体中CO2质量分数逐渐增加时,其黏度变化呈线性下降,CO2质量分数每升高0.1%,均相体黏度下降约为52 Pa s;加大剪切速率可以大幅度降低均相体的黏度,当CO2质量分数为0.5%的均相体在剪切速率从(120/π)/s增加到(240/π)/s时其黏度下降趋势最大,值为40%。展开更多
基金Project(50372086) supported by the National Natural Science Foundation of China
文摘A kind of fine and quasi-spherical Y2O3:Eu3+ phosphor was prepared by firing a preparative precursor at 1 200 ℃ for 2 h with the molten salts of Na2CO3, S and NaCl. The precursor was obtained by homogeneous precipitation of yttrium and europium with oxalic acid when using EDTA, citric acid or starch as complexant. The structure and morphology of the phosphors were characterized by XRD and SEM, respectively. The influence of complexing environment, firing temperature and molten salts on formation of the phosphor Y2O3:Eu3+ was discussed. The result show that the prepared Y2O3:Eu3+ phosphor is of quasi-spherical structure with size of 2-3 μm. Its luminescent intensity is 30% higher than that of the same phosphor prepared by the same procedure but without molten salts, and is 5% higher than that of commercial Y2O3:Eu3+ red phosphor.
文摘Bocs, which is the abbreviated form of bimodule over a categary with coalgebra structure, was introduced by Kleiner and Rojter in 1975 and developed by Drozd in 1979, then formulated by Crawley-Boevey in 1988. Let k be an algebraically closed field, A a finitely dimensional k-algebra. Then there exists a bocs B over k associated to A. From this relation Drozd proved one of the most important theorems in representation theory of algebra, namely, a finitely dimensional k-algebra is either of representation tame type or of representation wild type,
基金Supported by the Computer Network and Information Security Foundation of Ministry of Education Laboratory(20040108)
文摘This paper constructs the probability model of the multi-valued KM_1M_2 clock controlled generator,and discusses the probability distributing,homogeneous Markov property,ergodic property,strict placidity,numeral character and the property of large numbers of the random variables with this kind of output sequence.It gets the probability formula of the coincidence of the output sequence with the input sequence,and gives important reference to the design and analysis of the multi-valued key stream clock controlled generator in cryptography.
文摘通过建立含有类似锥板流变仪结构的实验平台对不同的温度、压力、剪切速率以及CO2质量分数等工艺条件下聚苯乙烯(PS)/超临界CO2(ScCO2)均相体的流变性能展开研究。结果表明:压力的升高会增加均相体的黏度,压力由7.5 MPa升高到10.5 MPa时,CO2质量分数为0.5%的均相体黏度增加了140 Pa s,约为原来的4.6%;增加温度则会降低均相体黏度,而且随着温度的升高,黏度的下降趋势在逐渐减小,温度从443.15 K逐渐增加到473.15 K时,CO2质量分数为0.5%的均相体黏度的减少值分别为778,482,327 Pa s;当均相体中CO2质量分数逐渐增加时,其黏度变化呈线性下降,CO2质量分数每升高0.1%,均相体黏度下降约为52 Pa s;加大剪切速率可以大幅度降低均相体的黏度,当CO2质量分数为0.5%的均相体在剪切速率从(120/π)/s增加到(240/π)/s时其黏度下降趋势最大,值为40%。
