The separation and identification of the ephedrines(cathine,norephe-drine,ephedrine,pseudoephedrine,methylephedrine and ethylephedrine)and their derivatives obtained from TFAA,MSTFA,MSTFA+MBTFA and MSTFA+Ethyl acetate...The separation and identification of the ephedrines(cathine,norephe-drine,ephedrine,pseudoephedrine,methylephedrine and ethylephedrine)and their derivatives obtained from TFAA,MSTFA,MSTFA+MBTFA and MSTFA+Ethyl acetate deriva- tization were carried out by GC/MSD.展开更多
To balance the convergence rate and steadystate error of blind source separation(BSS) algorithms, an efficient equivariant adaptive separation via independence(Efficient EASI) algorithm is proposed based on separating...To balance the convergence rate and steadystate error of blind source separation(BSS) algorithms, an efficient equivariant adaptive separation via independence(Efficient EASI) algorithm is proposed based on separating indicator, which was derived from the convergence condition of EASI, and can be used to evaluate the separation degree of separated signals. Furthermore, a nonlinear monotone increasing function between suitable step sizes and separating indicator is constructed to adaptively adjust step sizes, and forgetting factor is employed to weaken effects of data at the initial stage. Numerical case studies and experimental studies on a test bed with shell structures are provided to validate the efficiency improvement of the proposed method. This study can benefit for vibration & acoustic monitoring and control, and machinery condition monitoring and fault diagnosis.展开更多
[Objective]The study aimed to develop microecological preparations for poultry as potential substitutes for certain antibiotics.[Method]Acid-producing bacteria were isolated and purified from chicken cecal chyme,follo...[Objective]The study aimed to develop microecological preparations for poultry as potential substitutes for certain antibiotics.[Method]Acid-producing bacteria were isolated and purified from chicken cecal chyme,followed by evaluation of their antibacterial properties and molecular biological identification.Additionally,their in vitro tolerance and safety were experimentally assessed.[Result]A lactic acid bacterium with notable antibacterial properties was isolated and identified as Lactobacillus plantarum.This strain exhibited inhibitory effects against the pathogenic indicator bacteria Escherichia coli and Staphylococcus aureus,with maximum inhibition zone diameters measuring 8.95 and 6.43 mm,respectively.In vitro tolerance tests demonstrated that this strain was capable of growth within a pH range of 4-8,tolerated bile salt concentrations between 0.10%and 0.30%,and adapted to simulated gastric and intestinal fluid environments.Safety test revealed that the strain exhibited no hemolytic activity and was deemed safe in mouse safety assessments.[Conclusion]A chicken-derived L.plantarum strain has been identified,exhibiting notable antibacterial activity,stress tolerance,probiotic efficacy,and safety.This strain holds significant potential and market prospects for the development of microecological preparations.展开更多
To determine the fatty acids in milk powders,the fatty oils of milk powders were extracted by Rose-Gettlieb method,the fatty acids in the fatty oils were esterified by potassium hydroxide-methanol,and then analyzed by...To determine the fatty acids in milk powders,the fatty oils of milk powders were extracted by Rose-Gettlieb method,the fatty acids in the fatty oils were esterified by potassium hydroxide-methanol,and then analyzed by gas chromatography-mass spectrometry (GC-MS).The results indicate that main fatty acids’ carbon chain were from 8 to 24,each fatty acid has different conents in different samples and the content was determined by area normalization.展开更多
文摘The separation and identification of the ephedrines(cathine,norephe-drine,ephedrine,pseudoephedrine,methylephedrine and ethylephedrine)and their derivatives obtained from TFAA,MSTFA,MSTFA+MBTFA and MSTFA+Ethyl acetate deriva- tization were carried out by GC/MSD.
基金supported by the National Natural Science Foundation of China(Grant No.51305329)the China Postdoctoral Science Foundation(Grant No.2014T70911)+1 种基金the Doctoral Foundation of Education Ministry of China(Grant No.20130201120040)Basic Research Project of Natural Science in Shaanxi Province(Grant No.2015JQ5183)
文摘To balance the convergence rate and steadystate error of blind source separation(BSS) algorithms, an efficient equivariant adaptive separation via independence(Efficient EASI) algorithm is proposed based on separating indicator, which was derived from the convergence condition of EASI, and can be used to evaluate the separation degree of separated signals. Furthermore, a nonlinear monotone increasing function between suitable step sizes and separating indicator is constructed to adaptively adjust step sizes, and forgetting factor is employed to weaken effects of data at the initial stage. Numerical case studies and experimental studies on a test bed with shell structures are provided to validate the efficiency improvement of the proposed method. This study can benefit for vibration & acoustic monitoring and control, and machinery condition monitoring and fault diagnosis.
基金Supported by Regional Development Project of Fujian Provincial Department of Science and Technology(2022N3017).
文摘[Objective]The study aimed to develop microecological preparations for poultry as potential substitutes for certain antibiotics.[Method]Acid-producing bacteria were isolated and purified from chicken cecal chyme,followed by evaluation of their antibacterial properties and molecular biological identification.Additionally,their in vitro tolerance and safety were experimentally assessed.[Result]A lactic acid bacterium with notable antibacterial properties was isolated and identified as Lactobacillus plantarum.This strain exhibited inhibitory effects against the pathogenic indicator bacteria Escherichia coli and Staphylococcus aureus,with maximum inhibition zone diameters measuring 8.95 and 6.43 mm,respectively.In vitro tolerance tests demonstrated that this strain was capable of growth within a pH range of 4-8,tolerated bile salt concentrations between 0.10%and 0.30%,and adapted to simulated gastric and intestinal fluid environments.Safety test revealed that the strain exhibited no hemolytic activity and was deemed safe in mouse safety assessments.[Conclusion]A chicken-derived L.plantarum strain has been identified,exhibiting notable antibacterial activity,stress tolerance,probiotic efficacy,and safety.This strain holds significant potential and market prospects for the development of microecological preparations.
文摘To determine the fatty acids in milk powders,the fatty oils of milk powders were extracted by Rose-Gettlieb method,the fatty acids in the fatty oils were esterified by potassium hydroxide-methanol,and then analyzed by gas chromatography-mass spectrometry (GC-MS).The results indicate that main fatty acids’ carbon chain were from 8 to 24,each fatty acid has different conents in different samples and the content was determined by area normalization.
