Single step and multi step CARE processes are optimized by computer simulations based on the mathematical model proposed previously. The product of purification factor and recovery yield is used as the objective fun...Single step and multi step CARE processes are optimized by computer simulations based on the mathematical model proposed previously. The product of purification factor and recovery yield is used as the objective function for optimizing a single step process. The objective function for the optimization of a multi step process is considered to obtain an anticipated product purity at a maximum recovery yield and a minimum number of CARE inividuals. Pairs of the operating conditions (eluant and affinity recycle flow rates) exist to give the maximums of above objective functions when membrane rejections to ligates and contaminants are equal in value. The optimum affinity recycle flow rate decreases with the increase of membrane rejections and equilibrium binding fractions of ligates. For a multi step process, when contaminants are rejected less than ligate, only one pair of the optimum eluant and affinity recycle flow rates exists.展开更多
Non-contact atomic force microscopy（nc-AFM） atomic-scale imaging process of monocrystalline silicon surface using capped single-wall carbon nanotube tip is simulated by molecular dynamic method. The simulation resuh...Non-contact atomic force microscopy（nc-AFM） atomic-scale imaging process of monocrystalline silicon surface using capped single-wall carbon nanotube tip is simulated by molecular dynamic method. The simulation resuhs show that the nc-AFM imaging force mainly comes from the C-Si and C-C chemical covalent bonding forces, especially the former, the nonbonding Van der Waals force change is small during the range of stable imaging height. When the tip-surface distance is smaller than the stable imaging height, several neighboring carbon atoms at the tip apex are attracted, and some of them jump onto the sample surface. Finally the tip apex configuration is destroyed with the tip indenting further.展开更多
This paper deals with experimental study of flow field of starting process in two-dimensional, single-stage supersonic ejector on different air total pressure. Schlieren pictures of flow field were taken, static press...This paper deals with experimental study of flow field of starting process in two-dimensional, single-stage supersonic ejector on different air total pressure. Schlieren pictures of flow field were taken, static pressure distribu-tions on side wall were measured. The obtained results show that, on critical pressure, the starting main shock waves in ejector oscillated back and forth between the second throat and the middle section of the mixing chamber, it causes the pressure in the second half of the mixing chamber acutely fluctuated .When the working pressure of the active flow is higher than the critical starting pressure, ejector starts normally and the inner flow-field of the mixing chamber keeps stable and the shock waves in the second throat have a certain degree of oscillation . After ejector starts, the operating pressure of the active flow may be lower than the starting pressure .展开更多
文摘Single step and multi step CARE processes are optimized by computer simulations based on the mathematical model proposed previously. The product of purification factor and recovery yield is used as the objective function for optimizing a single step process. The objective function for the optimization of a multi step process is considered to obtain an anticipated product purity at a maximum recovery yield and a minimum number of CARE inividuals. Pairs of the operating conditions (eluant and affinity recycle flow rates) exist to give the maximums of above objective functions when membrane rejections to ligates and contaminants are equal in value. The optimum affinity recycle flow rate decreases with the increase of membrane rejections and equilibrium binding fractions of ligates. For a multi step process, when contaminants are rejected less than ligate, only one pair of the optimum eluant and affinity recycle flow rates exists.
文摘Non-contact atomic force microscopy（nc-AFM） atomic-scale imaging process of monocrystalline silicon surface using capped single-wall carbon nanotube tip is simulated by molecular dynamic method. The simulation resuhs show that the nc-AFM imaging force mainly comes from the C-Si and C-C chemical covalent bonding forces, especially the former, the nonbonding Van der Waals force change is small during the range of stable imaging height. When the tip-surface distance is smaller than the stable imaging height, several neighboring carbon atoms at the tip apex are attracted, and some of them jump onto the sample surface. Finally the tip apex configuration is destroyed with the tip indenting further.
文摘This paper deals with experimental study of flow field of starting process in two-dimensional, single-stage supersonic ejector on different air total pressure. Schlieren pictures of flow field were taken, static pressure distribu-tions on side wall were measured. The obtained results show that, on critical pressure, the starting main shock waves in ejector oscillated back and forth between the second throat and the middle section of the mixing chamber, it causes the pressure in the second half of the mixing chamber acutely fluctuated .When the working pressure of the active flow is higher than the critical starting pressure, ejector starts normally and the inner flow-field of the mixing chamber keeps stable and the shock waves in the second throat have a certain degree of oscillation . After ejector starts, the operating pressure of the active flow may be lower than the starting pressure .
