Curcuma wenyujin has been widely used as a traditional medicine in China. In this paper a strategy for the quantitative determination of the polysaccharide by a phenol-sulfuric acid method was described. Involved in t...Curcuma wenyujin has been widely used as a traditional medicine in China. In this paper a strategy for the quantitative determination of the polysaccharide by a phenol-sulfuric acid method was described. Involved in three factors, 5% phenol volume, H2SO4 volume, and temperature of water bath, we adopted the L9（3）3 orthogonal array design to gain the optimal colorimetric method. 3.0 ml of polysaccharide solution, 1.0 ml, 5% phenol and 7.0 ml H2SO4 were mixed with constant stirring in a glass vessel, and then kept in a water bath at 40 ℃. After cooling to room temperature for 20 min, the absorbance values were recorded by the UV-2501 PC spectrometer at the wavelength range of 485 nm. The polysaccharide content in Curcuma wenyujin were 3.21%, 3.23%, 3.20%, 3.18~/0, 3.22% and 2.38%, respectively. All results showed that this method was adequate, valid and applicable, may be applied to the determination of other bacterial polysaccharide as well.展开更多
LiMnOand LiNiAlyMnO（x= 0.50;y = 0.05-0.50） powders have been synthesized via facile solgel method using Behenic acid as active cheiating agent.The synthesized samples are subjected to physical characterizations such...LiMnOand LiNiAlyMnO（x= 0.50;y = 0.05-0.50） powders have been synthesized via facile solgel method using Behenic acid as active cheiating agent.The synthesized samples are subjected to physical characterizations such as thermo gravimetric analysis（TG/DTA）,X-ray diffraction（XRD）,Fourier transform infrared spectroscopy（FT-IR）,field-emission scanning electron microscopy（FESEM）,transmission electron microscopy（TEM） and electrochemical studies viz.,galvanostatic cycling properties,electrochemical impedance spectroscopy（EIS） and differential capacity curves（dQ/dE）.Finger print XRD patterns of LiMnOand LiNiAlMnOfortify the high degree of crystallinity with better phase purity.FESEM images of the undoped pristine spinel illustrate uniform spherical grains surface morphology with an average particle size of 0.5 μm while Ni doped particles depict the spherical grains growth（50nm） with ice-cube surface morphology.TEM images of the spinel LiMnOshows the uniform spherical morphology with particle size of（100 nm） while low level of Al-doping spinel（LiNio.5Alo.05Mn1.45O4） displaying cloudy particles with agglomerated particles of（50nm）.The LiMnOsamples calcined at 850℃ deliver the discharge capacity of 130 mAh/g in the first cycle corresponds to 94%coiumbic efficiency with capacity fade of 1.5 mAh/g/cycle over the investigated 10 cycles.Among all four dopant compositions investigated,LiNiAlMnOdelivers the maximum discharge capacity of 126 mAh/g during the first cycle and shows the stable cycling performance with low capacity fade of 1 mAh/g/cycle（capacity retention of 92%） over the investigated 10 cycles.Electrochemical impedance studies of spinel LiMnOand LiNiAlMnOdepict the high and low real polarization of 1562 and 1100 Ω.展开更多
[ Objective ] In order to get the standard substance of Jinggangmycin used in quality control, Jinggangmycin was purified from its original pesticide and its content was determined, t Method] Mixed solvents were selec...[ Objective ] In order to get the standard substance of Jinggangmycin used in quality control, Jinggangmycin was purified from its original pesticide and its content was determined, t Method] Mixed solvents were selected to recrystallize Jinggangmycin （content 62% ）. Phenol-sulfuric acid colofirnetric method was adopted to determine its content, and the effects of different determination conditions on the content results were also studied. E Result~ The purity of the samples after re-eryatallization was increased to 97.7%. The optimal conditions for phenol-sulfuric acid colorimetric method to determine the content of Jinggan^nyein were as follows： anhydrous glucose as control sample, 5% phenol, 1.0 ml phenol solution, 5.0 nfl sulfuric acid, stilly placed for20 min after reaction, 490 nm as detec- tion wavelength; the correlation coefficient of glucose standard curve （ R2 ） was 0. 993 9; the average recovery of standard addition was 99.72%, RSD was 0. 362 8%. ~ Conclusion] Re-cryatallization is a good way to refine Jinggan^nycin. Phenol-sulfuric acid colorimetric method can be used to determine the content of Jinggangmycin with simple operation, high accuracy and strong reliability, which can be widely applied in industrial production.展开更多
The equipment for surface tension measurement by the improved differential maximum bubble pressure method was built and tested.The surface tension of a binary mixture of p-xylene and acetic acid was measured over the ...The equipment for surface tension measurement by the improved differential maximum bubble pressure method was built and tested.The surface tension of a binary mixture of p-xylene and acetic acid was measured over the entire concentration range from 303.15 K to 343.15 K under atmospheric pressure.The experimental values were correlated with two methods.It is useful for PTA plant design.展开更多
文摘Curcuma wenyujin has been widely used as a traditional medicine in China. In this paper a strategy for the quantitative determination of the polysaccharide by a phenol-sulfuric acid method was described. Involved in three factors, 5% phenol volume, H2SO4 volume, and temperature of water bath, we adopted the L9（3）3 orthogonal array design to gain the optimal colorimetric method. 3.0 ml of polysaccharide solution, 1.0 ml, 5% phenol and 7.0 ml H2SO4 were mixed with constant stirring in a glass vessel, and then kept in a water bath at 40 ℃. After cooling to room temperature for 20 min, the absorbance values were recorded by the UV-2501 PC spectrometer at the wavelength range of 485 nm. The polysaccharide content in Curcuma wenyujin were 3.21%, 3.23%, 3.20%, 3.18~/0, 3.22% and 2.38%, respectively. All results showed that this method was adequate, valid and applicable, may be applied to the determination of other bacterial polysaccharide as well.
基金support given under the "Brain Pool Program of the Korean Federation of Science and Technology Societies" (KOFST), Republic of South Koreasupported by the Human Resources Development Program (No. 20124010203270) of the Korea Institute of Energy Technology EvaluationPlanning (KETEP) grant funded by the Korea Government Ministry of Trade, Industry and Energy
文摘LiMnOand LiNiAlyMnO（x= 0.50;y = 0.05-0.50） powders have been synthesized via facile solgel method using Behenic acid as active cheiating agent.The synthesized samples are subjected to physical characterizations such as thermo gravimetric analysis（TG/DTA）,X-ray diffraction（XRD）,Fourier transform infrared spectroscopy（FT-IR）,field-emission scanning electron microscopy（FESEM）,transmission electron microscopy（TEM） and electrochemical studies viz.,galvanostatic cycling properties,electrochemical impedance spectroscopy（EIS） and differential capacity curves（dQ/dE）.Finger print XRD patterns of LiMnOand LiNiAlMnOfortify the high degree of crystallinity with better phase purity.FESEM images of the undoped pristine spinel illustrate uniform spherical grains surface morphology with an average particle size of 0.5 μm while Ni doped particles depict the spherical grains growth（50nm） with ice-cube surface morphology.TEM images of the spinel LiMnOshows the uniform spherical morphology with particle size of（100 nm） while low level of Al-doping spinel（LiNio.5Alo.05Mn1.45O4） displaying cloudy particles with agglomerated particles of（50nm）.The LiMnOsamples calcined at 850℃ deliver the discharge capacity of 130 mAh/g in the first cycle corresponds to 94%coiumbic efficiency with capacity fade of 1.5 mAh/g/cycle over the investigated 10 cycles.Among all four dopant compositions investigated,LiNiAlMnOdelivers the maximum discharge capacity of 126 mAh/g during the first cycle and shows the stable cycling performance with low capacity fade of 1 mAh/g/cycle（capacity retention of 92%） over the investigated 10 cycles.Electrochemical impedance studies of spinel LiMnOand LiNiAlMnOdepict the high and low real polarization of 1562 and 1100 Ω.
文摘[ Objective ] In order to get the standard substance of Jinggangmycin used in quality control, Jinggangmycin was purified from its original pesticide and its content was determined, t Method] Mixed solvents were selected to recrystallize Jinggangmycin （content 62% ）. Phenol-sulfuric acid colofirnetric method was adopted to determine its content, and the effects of different determination conditions on the content results were also studied. E Result~ The purity of the samples after re-eryatallization was increased to 97.7%. The optimal conditions for phenol-sulfuric acid colorimetric method to determine the content of Jinggan^nyein were as follows： anhydrous glucose as control sample, 5% phenol, 1.0 ml phenol solution, 5.0 nfl sulfuric acid, stilly placed for20 min after reaction, 490 nm as detec- tion wavelength; the correlation coefficient of glucose standard curve （ R2 ） was 0. 993 9; the average recovery of standard addition was 99.72%, RSD was 0. 362 8%. ~ Conclusion] Re-cryatallization is a good way to refine Jinggan^nycin. Phenol-sulfuric acid colorimetric method can be used to determine the content of Jinggangmycin with simple operation, high accuracy and strong reliability, which can be widely applied in industrial production.
文摘The equipment for surface tension measurement by the improved differential maximum bubble pressure method was built and tested.The surface tension of a binary mixture of p-xylene and acetic acid was measured over the entire concentration range from 303.15 K to 343.15 K under atmospheric pressure.The experimental values were correlated with two methods.It is useful for PTA plant design.
