The control of the stability of the filament tension is one of the crucial techniques ensuring the component quality of the composite materials. The open-loop tension control system, with industrial control computer a...The control of the stability of the filament tension is one of the crucial techniques ensuring the component quality of the composite materials. The open-loop tension control system, with industrial control computer as the core, magnetic particle clutch as the actuator, equipped with compensation technique is researched and manufactured. It can assure the tension control stability of the yarn in filament winding process and increase the control precision of the whole system.展开更多
A novel power and cooling system combined system which coupled organic Rankine cycle(ORC) with vapor compression refrigeration cycle(VCRC) was proposed. R245 fa and butane were selected as the working fluid for the po...A novel power and cooling system combined system which coupled organic Rankine cycle(ORC) with vapor compression refrigeration cycle(VCRC) was proposed. R245 fa and butane were selected as the working fluid for the power and refrigeration cycle, respectively. A performance comparison and analysis for the combined system was presented. The results show that dual-pressure ORC-VCRC system can achieve an increase of 7.1% in thermal efficiency and 6.7% in exergy efficiency than that of basic ORC-VCRC. Intermediate pressure is a key parameter to both net power and exergy efficiency of dual-pressure ORC-VCRC system. Combined system can produce maximum net power and exergy efficiency at 0.85 MPa for intermediate pressure and 2.4 MPa for high pressure, respectively. However, superheated temperature at expander inlet has little impact on the two indicators. It can achieve higher overall COP, net power and exergy efficiency at smaller difference between condensation temperature and evaporation temperature of VCRC.展开更多
The effects of starting texture on he flow curves, and microstructure and texture evolutions of AZ31(Mg-3Al-1Zn-0.3Mn in wt.%) alloy during uniaxial compression at room temperature have been investigated by experiment...The effects of starting texture on he flow curves, and microstructure and texture evolutions of AZ31(Mg-3Al-1Zn-0.3Mn in wt.%) alloy during uniaxial compression at room temperature have been investigated by experiments and simulations. Two kinds of cylindrical compression samples were cut from the AZ31 extruded rod: one was cut with the compression direction parallel to the extruded direction(ED), and the other was cut with the compression axis perpendicular to the ED. The samples were termed as C//ED sample and C⊥ED sample, respectively. The results indicate that the general characteristics of flow curves and texture evolutions in both C⊥ED and C//ED samples during compression can be well explained by the relative activities of deformation mechanisms, which show a strong orientation dependence on the initial textures and the current texture. A significant yield behavior can be induced by {10-12} twinning at the starting deformation, and the lower yield stress in C⊥ED sample can be enhanced by the high activity of basal slip. The work hardening behavior is related to the activities of basal slip, pyramidal <c+a> slip, {10-12} twinning, as well as {10-11} twinning. However, the activity of prismatic slip is insensitive to the starting texture, and mostly negligible in all samples.展开更多
文摘The control of the stability of the filament tension is one of the crucial techniques ensuring the component quality of the composite materials. The open-loop tension control system, with industrial control computer as the core, magnetic particle clutch as the actuator, equipped with compensation technique is researched and manufactured. It can assure the tension control stability of the yarn in filament winding process and increase the control precision of the whole system.
基金Project(12C0379)supported by the Scientific Research Fund of Hunan Province,ChinaProject(13QDZ04)supported by the Scientific Research Foundation for Doctors of Xiangtan University,China
文摘A novel power and cooling system combined system which coupled organic Rankine cycle(ORC) with vapor compression refrigeration cycle(VCRC) was proposed. R245 fa and butane were selected as the working fluid for the power and refrigeration cycle, respectively. A performance comparison and analysis for the combined system was presented. The results show that dual-pressure ORC-VCRC system can achieve an increase of 7.1% in thermal efficiency and 6.7% in exergy efficiency than that of basic ORC-VCRC. Intermediate pressure is a key parameter to both net power and exergy efficiency of dual-pressure ORC-VCRC system. Combined system can produce maximum net power and exergy efficiency at 0.85 MPa for intermediate pressure and 2.4 MPa for high pressure, respectively. However, superheated temperature at expander inlet has little impact on the two indicators. It can achieve higher overall COP, net power and exergy efficiency at smaller difference between condensation temperature and evaporation temperature of VCRC.
基金supported by the National Natural Science Foundation of China(Grant No.51301040)
文摘The effects of starting texture on he flow curves, and microstructure and texture evolutions of AZ31(Mg-3Al-1Zn-0.3Mn in wt.%) alloy during uniaxial compression at room temperature have been investigated by experiments and simulations. Two kinds of cylindrical compression samples were cut from the AZ31 extruded rod: one was cut with the compression direction parallel to the extruded direction(ED), and the other was cut with the compression axis perpendicular to the ED. The samples were termed as C//ED sample and C⊥ED sample, respectively. The results indicate that the general characteristics of flow curves and texture evolutions in both C⊥ED and C//ED samples during compression can be well explained by the relative activities of deformation mechanisms, which show a strong orientation dependence on the initial textures and the current texture. A significant yield behavior can be induced by {10-12} twinning at the starting deformation, and the lower yield stress in C⊥ED sample can be enhanced by the high activity of basal slip. The work hardening behavior is related to the activities of basal slip, pyramidal <c+a> slip, {10-12} twinning, as well as {10-11} twinning. However, the activity of prismatic slip is insensitive to the starting texture, and mostly negligible in all samples.
