A reversed-phase high performance liquid chromatographic (RP-HPLC) method wasdeveloped and validated for the simultaneous deteimination of ceftazidime and tazobactam ininject-able powder. Methods Chromatography was ca...A reversed-phase high performance liquid chromatographic (RP-HPLC) method wasdeveloped and validated for the simultaneous deteimination of ceftazidime and tazobactam ininject-able powder. Methods Chromatography was carried out on Zorbax 300SB-C_(18) column using amixture of methanol and aqueous solution of phosphate buffer (pH = 5.6) as mobile phase. The UVdetection wavelength was 220 run. Results The linear ranges of ceftazidime and tazobactam were 0.62- 631.8 μg·mL^(-1) and 0.66 - 677.50 μg·mL^(-1), respectively. The average recoveries were 98.8%- 101.4% for ceftazidime, and 99,1% - 100.2% for tazobactam. The RSD values of inter-day andintra-day assays were lower than 1.5% for ceftazidime and 2.6% for tazobactam. Conclusion Thismethod is reproducible, simple, precise, and rapid for the quality control of ceftazidime andtazobactam in injectable powder.展开更多
Two kinds of semi-solid samples of AZ80−0.2Y−0.15Ca(wt.%)(AZ80M)magnesium alloy were prepared by semi-solid isothermal heat treatment of materials with and without equal channel angular pressing(ECAP)process.The micro...Two kinds of semi-solid samples of AZ80−0.2Y−0.15Ca(wt.%)(AZ80M)magnesium alloy were prepared by semi-solid isothermal heat treatment of materials with and without equal channel angular pressing(ECAP)process.The microstructures of initial and semi-solid treated samples were compared and analyzed.The results showed a significant difference in the liquid phase distribution between three-pass ECAP processed(3P)and as-received samples during the isothermal heating process.The semi-solid 3P sample showed a more uniform liquid distribution due to its smaller dihedral angle.Besides,the coarsening processes of solid grains of as-received and 3P samples were dominated by the coalescence and Ostwald ripening mechanism,respectively.The difference of coarsening processes was mainly related to the proportion of the high-angle grain boundaries in materials,which further affected the evolution behavior of the liquid pools.展开更多
It is found analytically that the parabolic radial profile of liquid velocity in cylindrical liquid-solid fluidized bed (LSFB) causes particles to circulate around some radial position. This is the main reason for liq...It is found analytically that the parabolic radial profile of liquid velocity in cylindrical liquid-solid fluidized bed (LSFB) causes particles to circulate around some radial position. This is the main reason for liquid-phase axial dispersions. The liquid-phase axial dispersion is depressed as the liquid velocity presents a flatter Bessel radial profile in a converging taper LSFB. The void fraction increases with axial distance in converging taper LSFB. The behavior produces less liquid-phase axial dispersion. Experimental results show good coincidence.展开更多
Objective To explore the transitive regularity of holistic constituents from the crude slices of the medicinal raw materials(MCS)to the formula granules(FG),fufang decoction(FD),and finally,the concentrated pills(CP)o...Objective To explore the transitive regularity of holistic constituents from the crude slices of the medicinal raw materials(MCS)to the formula granules(FG),fufang decoction(FD),and finally,the concentrated pills(CP)of Liuwei Dihuang Fufang(六味地黄复方,LWDHF).Methods Samples for MCS,FG,FD,and CP of LWDHF were obtained,and a fingerprint data-base was established using high-performance liquid chromatography(HPLC),by separating the samples in an XB-C18 column and analyzing the transitive regularity of components us-ing the total quantum statistical moment(TQSM),including total quantum zero moment(AUCT),total quantum first moment(MRTT),total quantum second moment(VRTT),and its similarity approach.The AUCT,MRTT,and VRTT were calculated based on the representative HPLC chromatograms of FG,FD,and CP of LWDHF.Results AUCT of FG,FD,and CP of LWDHF was 71804,46553,and 144646μV·s,respectively;MRTT was 14.43,14.54,and 18.85 min,respectively;and VRTT was 106.98,112.84,and 269.12 min2,respectively.Comparing the similarity of FG/FD,FG/CP and FD/CP of LWDHF,the TQSM similarity values were 98.66%,76.62%,and 75.37%,respectively,whereas the tradi-tional similarity evaluation values were 98.68%,85.43%,and 85.60%,respectively.Conclusion The results perform little distinction in the total composition between FG and FD,whereas some distinction existed between FD and CP.Experimental evidence,therefore indicates that FG could be used as the alternative of MCS in clinical applications.展开更多
To select the proper composition and obtain an overall material?microstructure?property relationship for Cu?Fe alloy, theeffect of Fe content on microstructure and properties of Cu?Fe-based composite coatings by laser...To select the proper composition and obtain an overall material?microstructure?property relationship for Cu?Fe alloy, theeffect of Fe content on microstructure and properties of Cu?Fe-based composite coatings by laser induction hybrid rapid claddingwas investigated. Microstructure characterization of the composite coatings was tested utilizing SEM, XRD and EDS. Microhardnessmeasurement was executed to evaluate the mechanical properties of the composite coatings. The results show that for low Fe content,the composite coating presents a feature that Fe-rich equiaxed dendrites are embedded in the Cu-rich matrix. With increasing Fecontent, the Fe-rich particles are dispersed in the Cu-rich matrix. With further increasing Fe content, large amounts of Cu-richparticles are homogeneously dispersed in the interdendrite of the Fe-rich matrix. Correspondingly, the average microhardness of thecomposite coatings increases gradually with the increase of Fe content and the microhardness of Cu14.5Fe83Si2C0.5 coating is muchtwice higher than that of the substrate.展开更多
The critical curves for binary systems of methane combined with nitrogen, carbon monoxide, carbon dioxide, ethane, propane, butane and water at temperatures from 125 K to 650 K and pressures from 3.5 MPa to 250 MPa we...The critical curves for binary systems of methane combined with nitrogen, carbon monoxide, carbon dioxide, ethane, propane, butane and water at temperatures from 125 K to 650 K and pressures from 3.5 MPa to 250 MPa were calculated by using Heilig-Franck equation of state. This equation of state contains a repulsion term and an attraction term for intermolecular interaction. With pairwise combination rules for these potentials, three adjustable parameters are needed. The results showed that the critical curves of the former six binary systems belonged to type I, and CH4＋H2O system belonged to type III. The calculated data were compared with the experimental data,which yielded good results for the pressure-temperature, pressure-composition and temperature-composition behaviors of the seven systems. Moreover, the values of the adjustable parameters were obtained from the calculation of the critical curves. They can also be used for other relevant calculation.展开更多
文摘A reversed-phase high performance liquid chromatographic (RP-HPLC) method wasdeveloped and validated for the simultaneous deteimination of ceftazidime and tazobactam ininject-able powder. Methods Chromatography was carried out on Zorbax 300SB-C_(18) column using amixture of methanol and aqueous solution of phosphate buffer (pH = 5.6) as mobile phase. The UVdetection wavelength was 220 run. Results The linear ranges of ceftazidime and tazobactam were 0.62- 631.8 μg·mL^(-1) and 0.66 - 677.50 μg·mL^(-1), respectively. The average recoveries were 98.8%- 101.4% for ceftazidime, and 99,1% - 100.2% for tazobactam. The RSD values of inter-day andintra-day assays were lower than 1.5% for ceftazidime and 2.6% for tazobactam. Conclusion Thismethod is reproducible, simple, precise, and rapid for the quality control of ceftazidime andtazobactam in injectable powder.
基金supported by Key Development Project of Sichuan Province(Grant No.2017GZ0399)。
文摘Two kinds of semi-solid samples of AZ80−0.2Y−0.15Ca(wt.%)(AZ80M)magnesium alloy were prepared by semi-solid isothermal heat treatment of materials with and without equal channel angular pressing(ECAP)process.The microstructures of initial and semi-solid treated samples were compared and analyzed.The results showed a significant difference in the liquid phase distribution between three-pass ECAP processed(3P)and as-received samples during the isothermal heating process.The semi-solid 3P sample showed a more uniform liquid distribution due to its smaller dihedral angle.Besides,the coarsening processes of solid grains of as-received and 3P samples were dominated by the coalescence and Ostwald ripening mechanism,respectively.The difference of coarsening processes was mainly related to the proportion of the high-angle grain boundaries in materials,which further affected the evolution behavior of the liquid pools.
基金Supported by the National Natural Science Foundation of China(No.29576251)
文摘It is found analytically that the parabolic radial profile of liquid velocity in cylindrical liquid-solid fluidized bed (LSFB) causes particles to circulate around some radial position. This is the main reason for liquid-phase axial dispersions. The liquid-phase axial dispersion is depressed as the liquid velocity presents a flatter Bessel radial profile in a converging taper LSFB. The void fraction increases with axial distance in converging taper LSFB. The behavior produces less liquid-phase axial dispersion. Experimental results show good coincidence.
基金Hunan Provincial Natural Science Foundation of China(2019JJ40220 and 2021JJ30514)Hunan Provincial Administration of Traditional Chinese Medicine(2021204and 2021073)+1 种基金Scientific Research Fund of Hunan Provincial Education Department(2021204 and 2021073)Pharmaceutical Open Fund of Domestic First-class Disciplines(Cultivation)of Hunan Province(2018YX11)。
文摘Objective To explore the transitive regularity of holistic constituents from the crude slices of the medicinal raw materials(MCS)to the formula granules(FG),fufang decoction(FD),and finally,the concentrated pills(CP)of Liuwei Dihuang Fufang(六味地黄复方,LWDHF).Methods Samples for MCS,FG,FD,and CP of LWDHF were obtained,and a fingerprint data-base was established using high-performance liquid chromatography(HPLC),by separating the samples in an XB-C18 column and analyzing the transitive regularity of components us-ing the total quantum statistical moment(TQSM),including total quantum zero moment(AUCT),total quantum first moment(MRTT),total quantum second moment(VRTT),and its similarity approach.The AUCT,MRTT,and VRTT were calculated based on the representative HPLC chromatograms of FG,FD,and CP of LWDHF.Results AUCT of FG,FD,and CP of LWDHF was 71804,46553,and 144646μV·s,respectively;MRTT was 14.43,14.54,and 18.85 min,respectively;and VRTT was 106.98,112.84,and 269.12 min2,respectively.Comparing the similarity of FG/FD,FG/CP and FD/CP of LWDHF,the TQSM similarity values were 98.66%,76.62%,and 75.37%,respectively,whereas the tradi-tional similarity evaluation values were 98.68%,85.43%,and 85.60%,respectively.Conclusion The results perform little distinction in the total composition between FG and FD,whereas some distinction existed between FD and CP.Experimental evidence,therefore indicates that FG could be used as the alternative of MCS in clinical applications.
基金Projects(51471084,61475117)supported by the National Natural Science Foundation of ChinaProject(13ZCZDGX01109)supported by Tianjin Municipal Science and Technology Commission of ChinaProject(20122BBE500031)supported by the Key Technology Project of Jiangxi Province in China
文摘To select the proper composition and obtain an overall material?microstructure?property relationship for Cu?Fe alloy, theeffect of Fe content on microstructure and properties of Cu?Fe-based composite coatings by laser induction hybrid rapid claddingwas investigated. Microstructure characterization of the composite coatings was tested utilizing SEM, XRD and EDS. Microhardnessmeasurement was executed to evaluate the mechanical properties of the composite coatings. The results show that for low Fe content,the composite coating presents a feature that Fe-rich equiaxed dendrites are embedded in the Cu-rich matrix. With increasing Fecontent, the Fe-rich particles are dispersed in the Cu-rich matrix. With further increasing Fe content, large amounts of Cu-richparticles are homogeneously dispersed in the interdendrite of the Fe-rich matrix. Correspondingly, the average microhardness of thecomposite coatings increases gradually with the increase of Fe content and the microhardness of Cu14.5Fe83Si2C0.5 coating is muchtwice higher than that of the substrate.
基金Supported by National Natural Science Foundation of China (No 20476071)
文摘The critical curves for binary systems of methane combined with nitrogen, carbon monoxide, carbon dioxide, ethane, propane, butane and water at temperatures from 125 K to 650 K and pressures from 3.5 MPa to 250 MPa were calculated by using Heilig-Franck equation of state. This equation of state contains a repulsion term and an attraction term for intermolecular interaction. With pairwise combination rules for these potentials, three adjustable parameters are needed. The results showed that the critical curves of the former six binary systems belonged to type I, and CH4＋H2O system belonged to type III. The calculated data were compared with the experimental data,which yielded good results for the pressure-temperature, pressure-composition and temperature-composition behaviors of the seven systems. Moreover, the values of the adjustable parameters were obtained from the calculation of the critical curves. They can also be used for other relevant calculation.
