The adsorption of low concentration of free acid by regenerable chitin is followed by electric conductance determination. The effect of acid concentration, content of functional amino groups, and ionic strength on ads...The adsorption of low concentration of free acid by regenerable chitin is followed by electric conductance determination. The effect of acid concentration, content of functional amino groups, and ionic strength on adsorption was discussed. Experimental results indicate that the active centre of regenerable chitin is the free amino groups on its surface, and that the rate of adsorption of free acid was found to be affected by two factors: the interaction between the adsorbent and the adsorbate in solution and that between the adsorbate molecules or ions in solution.展开更多
Optimal synthesis of a 3-DOF 4 limbs planar parallel mechanism with actuated redundancy is studied. The kinematics equation of the mechanism is developed and the topology of the mecha-nism is classified. The kinematic...Optimal synthesis of a 3-DOF 4 limbs planar parallel mechanism with actuated redundancy is studied. The kinematics equation of the mechanism is developed and the topology of the mecha-nism is classified. The kinematics and force properties of the mechanisms according to the topologies are compared. Furthermore, a global optimizing formulation is derived from the condition number that is a local index usually used to scaling the manipulability isotropy quantitatively. The optimiza-tion is solved by genetic algorithm. The numerical results show that the topology of the mechanisms can influence the kinematics and force property considerably, and the manipulation dexterity of the mechanisms can be improved distinctly by the given formulations and the suggested optimization algorithm.展开更多
Underactuated mechanical system has less independent inputs than the degrees of freedom（DOF） of the mechanism. The energy efficiency of this class of mechanical systems is an essential problem in practice. On the ba...Underactuated mechanical system has less independent inputs than the degrees of freedom（DOF） of the mechanism. The energy efficiency of this class of mechanical systems is an essential problem in practice. On the basis of the sufficient and necessary condition that concludes a single input nonlinear system is differentially flat, it is shown that the flat output of the single input underactuated mechanical system can be obtained by finding a smooth output function such that the relative degree of the system equals to the dimension of the state space. If the flat output of the underactuated system can be solved explicitly, and by constructing a smooth curve with satisfying given boundary conditions in fiat output space, an energy efficiency optimization method is proposed for the motion planning of the differentially flat underactuated mechanical systems. The inertia wheel pendulum is used to verify the proposed optimization method, and some numerical simulations show that the presented optimal motion planning method can efficaciously reduce the energy cost for given control tasks.展开更多
文摘The adsorption of low concentration of free acid by regenerable chitin is followed by electric conductance determination. The effect of acid concentration, content of functional amino groups, and ionic strength on adsorption was discussed. Experimental results indicate that the active centre of regenerable chitin is the free amino groups on its surface, and that the rate of adsorption of free acid was found to be affected by two factors: the interaction between the adsorbent and the adsorbate in solution and that between the adsorbate molecules or ions in solution.
基金This project is supported by National Natural Science Foundation of China (No.50475177)Municipal Natural Science Foundation of Beijing, China (No. 3062009).
文摘Optimal synthesis of a 3-DOF 4 limbs planar parallel mechanism with actuated redundancy is studied. The kinematics equation of the mechanism is developed and the topology of the mecha-nism is classified. The kinematics and force properties of the mechanisms according to the topologies are compared. Furthermore, a global optimizing formulation is derived from the condition number that is a local index usually used to scaling the manipulability isotropy quantitatively. The optimiza-tion is solved by genetic algorithm. The numerical results show that the topology of the mechanisms can influence the kinematics and force property considerably, and the manipulation dexterity of the mechanisms can be improved distinctly by the given formulations and the suggested optimization algorithm.
基金supported by National Natural Science Foundation of China (Grant No. 50475177)Beijing Municipal Natural Science Foundation, China (Grant No. 3062009)Funding Project for Academic Human Resources Development in Institutions of Higher Learning Under the Jurisdiction of Beijing Municipality, China (Grant No. PHR200906107).
文摘Underactuated mechanical system has less independent inputs than the degrees of freedom（DOF） of the mechanism. The energy efficiency of this class of mechanical systems is an essential problem in practice. On the basis of the sufficient and necessary condition that concludes a single input nonlinear system is differentially flat, it is shown that the flat output of the single input underactuated mechanical system can be obtained by finding a smooth output function such that the relative degree of the system equals to the dimension of the state space. If the flat output of the underactuated system can be solved explicitly, and by constructing a smooth curve with satisfying given boundary conditions in fiat output space, an energy efficiency optimization method is proposed for the motion planning of the differentially flat underactuated mechanical systems. The inertia wheel pendulum is used to verify the proposed optimization method, and some numerical simulations show that the presented optimal motion planning method can efficaciously reduce the energy cost for given control tasks.
