The M3-3x(PO4)2∶2xCe, xTb(M=Mg, Ca, Sr, Ba) phosphors were prepared by coprecipitation in this paper. Their phase structures, morphologies and luminescent properties were investigated by X-ray diffractometer, field e...The M3-3x(PO4)2∶2xCe, xTb(M=Mg, Ca, Sr, Ba) phosphors were prepared by coprecipitation in this paper. Their phase structures, morphologies and luminescent properties were investigated by X-ray diffractometer, field emission scanning electron microscopy and fluorospectrophotometer. The results indicate that the Ce3+ and Tb3+ enteres the host lattice because the XRD patterns of alkaline earth phosphate show no impurity phase, the SEM shows the spherical particles with an average size about 1 μm. The emission and excitation spectra are similar to rare earth phosphate. Concentration quenching of the Sr3(PO4)2∶Ce, Tb emission intensity was not observed even when the Tb3+ increases to 0.05, while the maximum emission intensity appears when x=0.04 in M3-3x(PO4)2∶2xCe, xTb(M=Ca, Ba) emission spectrum.展开更多
In order to clean production of chromium compounds, it is a critical process to remove aluminates and utilize aluminum compounds from artificial chromate alkali solutions. The effects of Na2 Cr O4 on the neutralizatio...In order to clean production of chromium compounds, it is a critical process to remove aluminates and utilize aluminum compounds from artificial chromate alkali solutions. The effects of Na2 Cr O4 on the neutralization curve, Al（OH）3 precipitation efficiency and induction period of bayerite were investigated. The results indicate that the neutralization curve of the artificial chromate alkali solutions shows three distinct regions and its induction period is longer than that of pure sodium aluminate solutions at the same aluminum concentration. And the decreased temperature and volume fraction of CO2 enhance the particle size of bayerite β-Al（OH）3. Bayerite composed of agglomerates of rods and cone frustums was obtained from alkali metal chromate solutions with 28.5% CO2（volume fraction） at temperatures ranging from 50 °C to 70 °C. Coarse bayerite with particle size（d50） from 24.2 μm to 29.3 μm extremely has few impurities, which is suitable for comprehensive utilization.展开更多
采用碱溶酸沉的方法提取南极磷虾分离蛋白(krill protein isolate,KPI),通过喷雾干燥和冷冻干燥的方式制备南极磷虾分离蛋白粉,并对这两种分离蛋白粉的结构及功能特性进行比较分析。结果表明:与冷冻干燥南极磷虾分离蛋白(freeze-dried k...采用碱溶酸沉的方法提取南极磷虾分离蛋白(krill protein isolate,KPI),通过喷雾干燥和冷冻干燥的方式制备南极磷虾分离蛋白粉,并对这两种分离蛋白粉的结构及功能特性进行比较分析。结果表明:与冷冻干燥南极磷虾分离蛋白(freeze-dried krill protein isolate,FKPI)相比,喷雾干燥南极磷虾分离蛋白(spray-dried krill protein isolate,SKPI)明度大,色泽较好;扫描电子显微镜结果显示,SKPI呈现出向内凹陷的不规则球状结构,而FKPI为薄层片状结构,SKPI的堆积密度高于FKPI;圆二色谱进一步表明,与KPI相比,SKPI和FKPI均呈现α-螺旋含量下降、β-转角含量增加的趋势,其中,SKPI的α-螺旋含量下降27.9%,β-转角含量增加12.2%,表明喷雾干燥后蛋白质的二级结构均从有规则的结构向无规则的结构转化;SKPI持水力、持油力、乳化稳定性和起泡性等均高于FKPI,而SKPI的溶解性、乳化性却比FKPI的差。可见,不同的干燥方式会改变南极磷虾分离蛋白的结构特性,并进一步影响其功能特性。展开更多
In spite of the role of alkali in enhancing oil recovery（EOR）, the formation of precipitation during alkaline-surfactant-polymer（ASP） flooding can severely do harm to the stratum of oil reservoirs, which has been ...In spite of the role of alkali in enhancing oil recovery（EOR）, the formation of precipitation during alkaline-surfactant-polymer（ASP） flooding can severely do harm to the stratum of oil reservoirs, which has been observed in situ tests of oil fields such as scale deposits found in oil stratum and at the bottom of oil wells. On the other hand,remarkable variation of stratum parameters, e.g., pore radius,porosity, and permeability due to scale formation considerably affects seepage flow and alkaline flooding process in return. The objective of this study is to firstly examine these mutual influential phenomena and corresponding mechanisms along with EOR during alkaline flooding when the effects of precipitation are no longer negligible. The chemical kinetic theory is applied for the specific fundamental reactions to describe the process of rock dissolution in silicabased reservoirs. The solubility product principle is used to analyze the mechanism of alkali scale formation in flooding.Then a 3D alkaline flooding coupling model accounting for the variation of porosity and permeability is established to quantitatively estimate the impact of alkali scales on reservoir stratum. The reliability of the present model is verified in comparison with indoor experiments and field tests of the Daqing oil field. Then, the numerical simulations on a 1/4well group in a 5-spot pattern show that the precipitation grows with alkali concentration, temperature, and injection pressure and, thus, reduces reservoir permeability and oil recovery correspondingly. As a result, the selection of alkaliwith a weak base is preferable in ASP flooding by tradeoff strategy.展开更多
基金Heilongjiang Province Education Office (10553013)the Open Laboratory of HUST
文摘The M3-3x(PO4)2∶2xCe, xTb(M=Mg, Ca, Sr, Ba) phosphors were prepared by coprecipitation in this paper. Their phase structures, morphologies and luminescent properties were investigated by X-ray diffractometer, field emission scanning electron microscopy and fluorospectrophotometer. The results indicate that the Ce3+ and Tb3+ enteres the host lattice because the XRD patterns of alkaline earth phosphate show no impurity phase, the SEM shows the spherical particles with an average size about 1 μm. The emission and excitation spectra are similar to rare earth phosphate. Concentration quenching of the Sr3(PO4)2∶Ce, Tb emission intensity was not observed even when the Tb3+ increases to 0.05, while the maximum emission intensity appears when x=0.04 in M3-3x(PO4)2∶2xCe, xTb(M=Ca, Ba) emission spectrum.
基金Project(51125018)supported by the National Science Found for Distinguished Young Scholars of ChinaProject(2011BAC06B07)supported by the National Key Technologies R&D Program of China+2 种基金Project(2011AA060704)supported by the National Hi-tech Research and Development Program of ChinaProjects(51204153,21106167)supported by the National Natural Science Foundation of ChinaProjects(2012M510552,2013T60175)supported by Financial Grant from the China Postdoctoral Science Foundation
文摘In order to clean production of chromium compounds, it is a critical process to remove aluminates and utilize aluminum compounds from artificial chromate alkali solutions. The effects of Na2 Cr O4 on the neutralization curve, Al（OH）3 precipitation efficiency and induction period of bayerite were investigated. The results indicate that the neutralization curve of the artificial chromate alkali solutions shows three distinct regions and its induction period is longer than that of pure sodium aluminate solutions at the same aluminum concentration. And the decreased temperature and volume fraction of CO2 enhance the particle size of bayerite β-Al（OH）3. Bayerite composed of agglomerates of rods and cone frustums was obtained from alkali metal chromate solutions with 28.5% CO2（volume fraction） at temperatures ranging from 50 °C to 70 °C. Coarse bayerite with particle size（d50） from 24.2 μm to 29.3 μm extremely has few impurities, which is suitable for comprehensive utilization.
文摘采用碱溶酸沉的方法提取南极磷虾分离蛋白(krill protein isolate,KPI),通过喷雾干燥和冷冻干燥的方式制备南极磷虾分离蛋白粉,并对这两种分离蛋白粉的结构及功能特性进行比较分析。结果表明:与冷冻干燥南极磷虾分离蛋白(freeze-dried krill protein isolate,FKPI)相比,喷雾干燥南极磷虾分离蛋白(spray-dried krill protein isolate,SKPI)明度大,色泽较好;扫描电子显微镜结果显示,SKPI呈现出向内凹陷的不规则球状结构,而FKPI为薄层片状结构,SKPI的堆积密度高于FKPI;圆二色谱进一步表明,与KPI相比,SKPI和FKPI均呈现α-螺旋含量下降、β-转角含量增加的趋势,其中,SKPI的α-螺旋含量下降27.9%,β-转角含量增加12.2%,表明喷雾干燥后蛋白质的二级结构均从有规则的结构向无规则的结构转化;SKPI持水力、持油力、乳化稳定性和起泡性等均高于FKPI,而SKPI的溶解性、乳化性却比FKPI的差。可见,不同的干燥方式会改变南极磷虾分离蛋白的结构特性,并进一步影响其功能特性。
基金supported by the National Basic Research Program of China (Grant 2005CB221300)the National Natural Science Foundation of China (Grant 11302234)
文摘In spite of the role of alkali in enhancing oil recovery（EOR）, the formation of precipitation during alkaline-surfactant-polymer（ASP） flooding can severely do harm to the stratum of oil reservoirs, which has been observed in situ tests of oil fields such as scale deposits found in oil stratum and at the bottom of oil wells. On the other hand,remarkable variation of stratum parameters, e.g., pore radius,porosity, and permeability due to scale formation considerably affects seepage flow and alkaline flooding process in return. The objective of this study is to firstly examine these mutual influential phenomena and corresponding mechanisms along with EOR during alkaline flooding when the effects of precipitation are no longer negligible. The chemical kinetic theory is applied for the specific fundamental reactions to describe the process of rock dissolution in silicabased reservoirs. The solubility product principle is used to analyze the mechanism of alkali scale formation in flooding.Then a 3D alkaline flooding coupling model accounting for the variation of porosity and permeability is established to quantitatively estimate the impact of alkali scales on reservoir stratum. The reliability of the present model is verified in comparison with indoor experiments and field tests of the Daqing oil field. Then, the numerical simulations on a 1/4well group in a 5-spot pattern show that the precipitation grows with alkali concentration, temperature, and injection pressure and, thus, reduces reservoir permeability and oil recovery correspondingly. As a result, the selection of alkaliwith a weak base is preferable in ASP flooding by tradeoff strategy.
