Affinity membrane was prepared with chitosan immobilized on the hydrophile- modified poly(vinylidene fluoride) (PVDF) membrane. Fourier transform infrared spectroscopy (FTIR.) analysis indicated that the contents of ...Affinity membrane was prepared with chitosan immobilized on the hydrophile- modified poly(vinylidene fluoride) (PVDF) membrane. Fourier transform infrared spectroscopy (FTIR.) analysis indicated that the contents of —NH2 and —OH groups increased and fluoride decreased on the membrane surface after modification. Using this kind of affinity membrane, the effects of operation parameters such as pH, ionic strength and flow rate, on the amount of endotoxin removed were investigated. The results showed that the equilibrium adsorption capacity and the dissociation constant of the affinity membrane to endotoxin were 21.4 EU·mg-1 membrane and 0.50EU·ml-1, respectively, at pH 7.0 and ionic strength 0.2 mol·L-1. Adsorption appeared to follow a typical Langmuir adsorption isotherm. At pH 5.0, ionic strength of 0.2 mol·L-1, the removal rate of endotoxin from BSA solution with the chitosan affinity membrane was up to 88.6% (11.50 EU·mg-1 membrane), and the recovery of BSA was 93.4% (0.187mg·mg-1 membrane), while at pH 11.0, ionic strength of 0.2mol·L-1, the removal rate of endotoxin from lysozyme solution was 72.4% (9.92EU·mg-1 membrane), and the recovery of lysozyme was 92.3% (0.104 mg·mg-1 membrane).展开更多
An integrated, efficient and effective performance management system, ＂dynamic performance management system＂, is presented, which covers the entire performance management process including measures design, analysis...An integrated, efficient and effective performance management system, ＂dynamic performance management system＂, is presented, which covers the entire performance management process including measures design, analysis, and dynamic update. The analysis of performance measures using causal loop diagrams, qualitative inference and analytic network process is mainly discussed. A real world case study is carried out throughout the paper to explain how the framework works. A software tool for DPMS, Performance Analyzer, is also introduced.展开更多
A new-style direct drive motor with double-stator structure is proposed. The structure and principle of the permanent-magnet (PM) brushless motor are discussed. On the basis of numerical calculation, the cogging torqu...A new-style direct drive motor with double-stator structure is proposed. The structure and principle of the permanent-magnet (PM) brushless motor are discussed. On the basis of numerical calculation, the cogging torque waveforms of the prototype motor when staggering two stators are analyzed. The method that can reduce torque ripple making use of the structure features of this motor is investigated. The results of numerical calculation and experiment indicate that designing motor with this kind of structure is a good scheme for increasing the power density.展开更多
基金Supported by the National Basic Research Program of China (No. 2003CB615706)
文摘Affinity membrane was prepared with chitosan immobilized on the hydrophile- modified poly(vinylidene fluoride) (PVDF) membrane. Fourier transform infrared spectroscopy (FTIR.) analysis indicated that the contents of —NH2 and —OH groups increased and fluoride decreased on the membrane surface after modification. Using this kind of affinity membrane, the effects of operation parameters such as pH, ionic strength and flow rate, on the amount of endotoxin removed were investigated. The results showed that the equilibrium adsorption capacity and the dissociation constant of the affinity membrane to endotoxin were 21.4 EU·mg-1 membrane and 0.50EU·ml-1, respectively, at pH 7.0 and ionic strength 0.2 mol·L-1. Adsorption appeared to follow a typical Langmuir adsorption isotherm. At pH 5.0, ionic strength of 0.2 mol·L-1, the removal rate of endotoxin from BSA solution with the chitosan affinity membrane was up to 88.6% (11.50 EU·mg-1 membrane), and the recovery of BSA was 93.4% (0.187mg·mg-1 membrane), while at pH 11.0, ionic strength of 0.2mol·L-1, the removal rate of endotoxin from lysozyme solution was 72.4% (9.92EU·mg-1 membrane), and the recovery of lysozyme was 92.3% (0.104 mg·mg-1 membrane).
文摘An integrated, efficient and effective performance management system, ＂dynamic performance management system＂, is presented, which covers the entire performance management process including measures design, analysis, and dynamic update. The analysis of performance measures using causal loop diagrams, qualitative inference and analytic network process is mainly discussed. A real world case study is carried out throughout the paper to explain how the framework works. A software tool for DPMS, Performance Analyzer, is also introduced.
文摘A new-style direct drive motor with double-stator structure is proposed. The structure and principle of the permanent-magnet (PM) brushless motor are discussed. On the basis of numerical calculation, the cogging torque waveforms of the prototype motor when staggering two stators are analyzed. The method that can reduce torque ripple making use of the structure features of this motor is investigated. The results of numerical calculation and experiment indicate that designing motor with this kind of structure is a good scheme for increasing the power density.
