The basic concepts and advantages of more/all electric aircraft （M/AEA） are briefly addressed. The combined starter/generator （CS/G） system is introduced as a key technology to enable M/AEA. Some important perform...The basic concepts and advantages of more/all electric aircraft （M/AEA） are briefly addressed. The combined starter/generator （CS/G） system is introduced as a key technology to enable M/AEA. Some important performance requirements for CS/G system are obtained. Based on these requirements, a high speed switched reluctance machine （SRM） is designed to operate as a starter/generator. The entire design process is mainly divided into two stages： electromagnetic design and thermal design. In electromagnetic design stage, the electromagnetic structure and dimensions of the machine and the number of phase winding turns per pole are obtained; the topology and main technical details of the converter are briefly introduced as well. In thermal design stage, a liquid-cooling system is designed based on the thermal analysis of the machine. In the end, the performances of the designed SRM are basically verified by simulation. To get high performances, the exciting angles are optimized in two different operating modes respectively, and the optimized performances in the motoring mode are given as well.展开更多
Inoculation of starter culture is a viable method to improve the quality of fermented foods,but its effect on the flavor metabolite profiles and the underlying mechanisms are still unclear.This study aimed to elucidat...Inoculation of starter culture is a viable method to improve the quality of fermented foods,but its effect on the flavor metabolite profiles and the underlying mechanisms are still unclear.This study aimed to elucidate the effects of starters(Lactiplantibacillus plantarum(LP)and Staphylococcus simulans(SS)individually or in combination(LS))on the flavor metabolite profiles of fermented sausages via metabolomics and genomics.L.plantarum markedly modified the composition of bacterial communities and made Lactobacillus spp.dominant in sausages(98.29%and 85.03%in LP and LS groups,respectively).Additionally,inoculation with a single starter,L.plantarum,and a mixed starter yielded similar non-volatile flavor metabolites,which were mainly characterized at the amino acid and peptide levels(relative intensities of 349.65 and 348.62 for the LP and LS groups,respectively).Meanwhile,the mixed starter group had the most volatile flavor metabolites(relative intensity of 34728.67),some of which were contributed by L.plantarum,such as ethyl acetate(relative intensities of 583.33 and 588.33 for the LP and LS groups,respectively)and benzaldehyde(relative intensities of 786.67 and 909.00 for the LP and LS groups,respectively),and several of which were generated by S.simulans,such as ethyl propionate(relative intensities of 214.67 and 136.67 for the SS and LS groups,respectively)and benzyl alcohol(relative intensities of 720.00 and 656.00 for the SS and LS groups,respectively).Furthermore,L.plantarum was found to possess more genes encoding peptidases(48)and carbohydrate-active enzymes(124),while S.simulans had more genes related to lipid hydrolysis(12).In conclusion,differences in the properties and combinations of indigenous strains play a crucial role in the generation of flavor metabolites in sausages.展开更多
A new type of double salient starter/generator is presented, which can be used in aircraft Low Voltage Direct Current (LVDC), Variable Speed Constant Frequency (VSCF) and High Voltage Direct Current (HVDC) systems. Th...A new type of double salient starter/generator is presented, which can be used in aircraft Low Voltage Direct Current (LVDC), Variable Speed Constant Frequency (VSCF) and High Voltage Direct Current (HVDC) systems. The operational theory of the motor and generator is analyzed, and corresponding control strategies are given. An 18kW prototype has been implemented to verify the system performance. It is shown that the DSM S/G system possesses simple structure, high efficiency and flexible control. It is ap...展开更多
Freshly harvested paddy rice was randomly obtained from three different farms in “Ofada” town, Ogun State, Nigeria and processed according to the traditional parboiling method. The rice was inoculated singly with cu...Freshly harvested paddy rice was randomly obtained from three different farms in “Ofada” town, Ogun State, Nigeria and processed according to the traditional parboiling method. The rice was inoculated singly with cultures of Lactobacillus amylophilus, Leuconostoc mesenteroides, Saccharomyces uvarum and Saccharomyces cerevisiae which were isolated from the soak-water. In order to assess the effect of starter cultures on the soaking time of the rice, the pH and titratable acidity were determined at 12 h interval. The chemical composition and the sensory quality of the rice were also determined at the end of the soaking period while uninoculated rice served as control. The chemical composition of the rice as well as the pH and TTA of the soak-water were significantly (p < 0.05) different from the control while the processing time was shortened to 48 h. The rice inoculated with Saccharomyces uvarum and Saccharomyces cerevisae had the highest protein content and best sensory attributes.展开更多
This paper focuses on the simulation and test of the switched reluctance starter/generator systems. Through the emulational analysis of the initial starting torque, the optimal turn-on section of the power switches is...This paper focuses on the simulation and test of the switched reluctance starter/generator systems. Through the emulational analysis of the initial starting torque, the optimal turn-on section of the power switches is discovered. The fundamental theory of the generating operation is analyzed with the linearity model, and a new method is presented based on voltage pulse width modulation for the generating mode control. Through the steady-state and optimized emulation of the output power and system efficiency, the optimizational control approach for the generating mode over a wide speed range is introduced. At last, the test of the 3KW prototype system shows that the dynamic and static performance of this system is fine.展开更多
文摘The basic concepts and advantages of more/all electric aircraft （M/AEA） are briefly addressed. The combined starter/generator （CS/G） system is introduced as a key technology to enable M/AEA. Some important performance requirements for CS/G system are obtained. Based on these requirements, a high speed switched reluctance machine （SRM） is designed to operate as a starter/generator. The entire design process is mainly divided into two stages： electromagnetic design and thermal design. In electromagnetic design stage, the electromagnetic structure and dimensions of the machine and the number of phase winding turns per pole are obtained; the topology and main technical details of the converter are briefly introduced as well. In thermal design stage, a liquid-cooling system is designed based on the thermal analysis of the machine. In the end, the performances of the designed SRM are basically verified by simulation. To get high performances, the exciting angles are optimized in two different operating modes respectively, and the optimized performances in the motoring mode are given as well.
基金supported by the Priority Academic Program Development of Jiangsu Higher Education Institution(PAPD).
文摘Inoculation of starter culture is a viable method to improve the quality of fermented foods,but its effect on the flavor metabolite profiles and the underlying mechanisms are still unclear.This study aimed to elucidate the effects of starters(Lactiplantibacillus plantarum(LP)and Staphylococcus simulans(SS)individually or in combination(LS))on the flavor metabolite profiles of fermented sausages via metabolomics and genomics.L.plantarum markedly modified the composition of bacterial communities and made Lactobacillus spp.dominant in sausages(98.29%and 85.03%in LP and LS groups,respectively).Additionally,inoculation with a single starter,L.plantarum,and a mixed starter yielded similar non-volatile flavor metabolites,which were mainly characterized at the amino acid and peptide levels(relative intensities of 349.65 and 348.62 for the LP and LS groups,respectively).Meanwhile,the mixed starter group had the most volatile flavor metabolites(relative intensity of 34728.67),some of which were contributed by L.plantarum,such as ethyl acetate(relative intensities of 583.33 and 588.33 for the LP and LS groups,respectively)and benzaldehyde(relative intensities of 786.67 and 909.00 for the LP and LS groups,respectively),and several of which were generated by S.simulans,such as ethyl propionate(relative intensities of 214.67 and 136.67 for the SS and LS groups,respectively)and benzyl alcohol(relative intensities of 720.00 and 656.00 for the SS and LS groups,respectively).Furthermore,L.plantarum was found to possess more genes encoding peptidases(48)and carbohydrate-active enzymes(124),while S.simulans had more genes related to lipid hydrolysis(12).In conclusion,differences in the properties and combinations of indigenous strains play a crucial role in the generation of flavor metabolites in sausages.
文摘A new type of double salient starter/generator is presented, which can be used in aircraft Low Voltage Direct Current (LVDC), Variable Speed Constant Frequency (VSCF) and High Voltage Direct Current (HVDC) systems. The operational theory of the motor and generator is analyzed, and corresponding control strategies are given. An 18kW prototype has been implemented to verify the system performance. It is shown that the DSM S/G system possesses simple structure, high efficiency and flexible control. It is ap...
文摘Freshly harvested paddy rice was randomly obtained from three different farms in “Ofada” town, Ogun State, Nigeria and processed according to the traditional parboiling method. The rice was inoculated singly with cultures of Lactobacillus amylophilus, Leuconostoc mesenteroides, Saccharomyces uvarum and Saccharomyces cerevisiae which were isolated from the soak-water. In order to assess the effect of starter cultures on the soaking time of the rice, the pH and titratable acidity were determined at 12 h interval. The chemical composition and the sensory quality of the rice were also determined at the end of the soaking period while uninoculated rice served as control. The chemical composition of the rice as well as the pH and TTA of the soak-water were significantly (p < 0.05) different from the control while the processing time was shortened to 48 h. The rice inoculated with Saccharomyces uvarum and Saccharomyces cerevisae had the highest protein content and best sensory attributes.
文摘This paper focuses on the simulation and test of the switched reluctance starter/generator systems. Through the emulational analysis of the initial starting torque, the optimal turn-on section of the power switches is discovered. The fundamental theory of the generating operation is analyzed with the linearity model, and a new method is presented based on voltage pulse width modulation for the generating mode control. Through the steady-state and optimized emulation of the output power and system efficiency, the optimizational control approach for the generating mode over a wide speed range is introduced. At last, the test of the 3KW prototype system shows that the dynamic and static performance of this system is fine.
