A new, simple and highly sensitive kinetic method for the determination oftrace iron (III) has been developed based on the catalytic effect of iron (III) on colorreaction of p-amino-N, N-dimethylaniline dihydrochlorid...A new, simple and highly sensitive kinetic method for the determination oftrace iron (III) has been developed based on the catalytic effect of iron (III) on colorreaction of p-amino-N, N-dimethylaniline dihydrochloride (p-DMA) oxidated by hydrogenperoxide. The reaction is followed spectrophotometrically by measuring the absorbanceat 510 nm. The detection limit is 4.47×10-11 g/ml, and the calibration curve is linear inthe range of 0-0.10μg Fe(III) /25 ml with a relative standard deviation of ±3.25%. Themethod has been applied to the determination of iron in tap-water, chemical reagents andhuman hair.展开更多
In order to study the settling mechanism of particles in an air-solid magnetically stabilized fluidized bed(MSFB) for separation,we carried out free settling and quasi-zero settling tests on the tracing particles.The ...In order to study the settling mechanism of particles in an air-solid magnetically stabilized fluidized bed(MSFB) for separation,we carried out free settling and quasi-zero settling tests on the tracing particles.The results show that the main resistance forces as the tracing particles settled in an air-solid MSFB were motion resistance force and yield force.The motion resistance and yield forces greatly hindered the free settling of the particles by greatly decreasing the acceleration for settling process of the particles.The acceleration decreased from 3022.62 cm/s 2 to zero in 0.1 s,and in the end,the particles stopped in the air-solid MSFB.The yield force on particles increased with increasing the magnetic field intensity,resulting in decrease of the quasi-zero settling displacement.However,the yield force on particles decreased with increasing the fluidized air velocity,leading to increase of the quasi-zero settling displacement.When the structure and operating parameters of the air-solid MSFB were set up,the yield stress on particles stopped in an air-solid MSFB was a function of diameter and density of particles.The settling displacements of equal diameter particles increased with increasing their densities,and the settling displacements of equal density particles increased with increasing their diameters.展开更多
Plasma membrane vesicles were prepared from the developing cotyledons of common beau (Phaseolus vulgaris L cv Diyundou) by aqueous two-phase partitioning and characterized as to their purity by assaying marker enzymes...Plasma membrane vesicles were prepared from the developing cotyledons of common beau (Phaseolus vulgaris L cv Diyundou) by aqueous two-phase partitioning and characterized as to their purity by assaying marker enzymes for other membranes.The putative plasma membrane fraction was minimally contaminated by membranes Other than plasma membrane and hence was of high purity. It exhibited a Ca2+dependent ATPase activity, which was inhibited by 1μ mol/L EB and promoted by calcium ionophore A23187. Such an activity was responsible for the observed ATPdependent 45Ca2+ uptake into inside-out plasma membrane vesicles. This process was stimulated by 0.6μmol/L CaM and 20μmol/L IAA but inhibited by 2μmol/L ABA and abolished by A23187. Possible role of cytoplasmic Ca2+ in mediating phytohormones activity is discussed.展开更多
Track theory rested on the foundation of the radial distribution of dose from δ rays as the central contribution of atomic physics to heavy ion radiobiology.Here,a new calculation of the radial distribution of dose i...Track theory rested on the foundation of the radial distribution of dose from δ rays as the central contribution of atomic physics to heavy ion radiobiology.Here,a new calculation of the radial distribution of dose is applied, in which the classical angular distribution of dose of delta rays and a logarithmic polynomial representation of the electron range-energy relation are used,to form the basis of the present thindown calculation.Calculations of inactivation cross sections for heavy ions in the track width regime displaying thindown for E.Colt B/r and Bs-1,and for Bacillus Subtilus are straightforward for these are 1-hit detectors,Calculations for V-79 hamster cells are more complex.They follow the original development of this model for eucaryotic cells,and make use of the cross sections calculated for hypothetical internal targets which are then asserted to be proportional to the measured cellular inactivation cross sections.The results are in reasonable agreement with experimental data.展开更多
文摘A new, simple and highly sensitive kinetic method for the determination oftrace iron (III) has been developed based on the catalytic effect of iron (III) on colorreaction of p-amino-N, N-dimethylaniline dihydrochloride (p-DMA) oxidated by hydrogenperoxide. The reaction is followed spectrophotometrically by measuring the absorbanceat 510 nm. The detection limit is 4.47×10-11 g/ml, and the calibration curve is linear inthe range of 0-0.10μg Fe(III) /25 ml with a relative standard deviation of ±3.25%. Themethod has been applied to the determination of iron in tap-water, chemical reagents andhuman hair.
基金supported by the National Natural Science Foundation of China (Nos. 51134022 and 51174203)the Key Project of Chinese National Programs for Fundamental Research and Development (No. 2012CB214904)+2 种基金the National Natural Science Foundation of China for Innovative Research Group (No. 50921002)the Natural Science Foundation of Jiangsu Province (No. BK2010002)the Fundamental Research Funds for the Central Universities (Nos. 2010QNB11 and 2010ZDP01A06)
文摘In order to study the settling mechanism of particles in an air-solid magnetically stabilized fluidized bed(MSFB) for separation,we carried out free settling and quasi-zero settling tests on the tracing particles.The results show that the main resistance forces as the tracing particles settled in an air-solid MSFB were motion resistance force and yield force.The motion resistance and yield forces greatly hindered the free settling of the particles by greatly decreasing the acceleration for settling process of the particles.The acceleration decreased from 3022.62 cm/s 2 to zero in 0.1 s,and in the end,the particles stopped in the air-solid MSFB.The yield force on particles increased with increasing the magnetic field intensity,resulting in decrease of the quasi-zero settling displacement.However,the yield force on particles decreased with increasing the fluidized air velocity,leading to increase of the quasi-zero settling displacement.When the structure and operating parameters of the air-solid MSFB were set up,the yield stress on particles stopped in an air-solid MSFB was a function of diameter and density of particles.The settling displacements of equal diameter particles increased with increasing their densities,and the settling displacements of equal density particles increased with increasing their diameters.
文摘Plasma membrane vesicles were prepared from the developing cotyledons of common beau (Phaseolus vulgaris L cv Diyundou) by aqueous two-phase partitioning and characterized as to their purity by assaying marker enzymes for other membranes.The putative plasma membrane fraction was minimally contaminated by membranes Other than plasma membrane and hence was of high purity. It exhibited a Ca2+dependent ATPase activity, which was inhibited by 1μ mol/L EB and promoted by calcium ionophore A23187. Such an activity was responsible for the observed ATPdependent 45Ca2+ uptake into inside-out plasma membrane vesicles. This process was stimulated by 0.6μmol/L CaM and 20μmol/L IAA but inhibited by 2μmol/L ABA and abolished by A23187. Possible role of cytoplasmic Ca2+ in mediating phytohormones activity is discussed.
文摘Track theory rested on the foundation of the radial distribution of dose from δ rays as the central contribution of atomic physics to heavy ion radiobiology.Here,a new calculation of the radial distribution of dose is applied, in which the classical angular distribution of dose of delta rays and a logarithmic polynomial representation of the electron range-energy relation are used,to form the basis of the present thindown calculation.Calculations of inactivation cross sections for heavy ions in the track width regime displaying thindown for E.Colt B/r and Bs-1,and for Bacillus Subtilus are straightforward for these are 1-hit detectors,Calculations for V-79 hamster cells are more complex.They follow the original development of this model for eucaryotic cells,and make use of the cross sections calculated for hypothetical internal targets which are then asserted to be proportional to the measured cellular inactivation cross sections.The results are in reasonable agreement with experimental data.
