This paper deals with the universal serial manipulator on the inverse kinematics problem of plane type,the fast working space solution method,and the obstacle avoidance path planning method. With the vector projection...This paper deals with the universal serial manipulator on the inverse kinematics problem of plane type,the fast working space solution method,and the obstacle avoidance path planning method. With the vector projection as the main constraint condition of the target,it proposes a general form of the inverse kinematics solution which does not depend on the robot configuration of freedom degree. By identifying the target vector direction maximum and minimum workspace boundary and determining the destination vector by thick search on the workspace boundary method,an expressing method of the polar coordinate form of work space is then introduced. Finally,according to the form of plane trajectory planning for obstacle avoidance problem,the method of solving the inverse kinematics solution of the concave and convex forms of the safe obstacle avoidance area is improved. The simulation results verify that the proposed method has feasibility and generality.展开更多
A one-step synthesized Ni-Mo-S catalyst supported on SiO2 was prepared and used for hydrodesulphurization （HDS） of dibenzothiophene （DBT）, and 4,6-dimethyl-dibenzothiophene （4,6-DMDBT）, and for hydrogenation of ...A one-step synthesized Ni-Mo-S catalyst supported on SiO2 was prepared and used for hydrodesulphurization （HDS） of dibenzothiophene （DBT）, and 4,6-dimethyl-dibenzothiophene （4,6-DMDBT）, and for hydrogenation of tetralin. The catalyst showed relatively high HDS activity with complete conversion of DBT and 4,6-DMDBT at temperature of 280℃ and a constant pressure of 435 psi. The HDS conversions of DBT and 4,6- DMDBT increased with increasing temperature and pressure, and decreasing liquid hourly space velocity （LHSV）. The HDS of DBT proceeded mostly through the direct desulphurization （DDS） pathway whereas that of 4,6-DMDBT occurred mainly through the hydrogenation- desulphurization （HYD） pathway. Although the catalyst showed up to 24% hydrogenation/dehydrogenation con- version oftetralin, it had low conversion and selectivity for ring opening and contraction due to the competitive adsorption of DBT and 4,6-DMDBT and insufficient acidic sites on the catalyst surface.展开更多
基金Sponsored by the National Natural Science Foundation of China(Grant No.51205074)the Specialized Research Fund for the Doctoral Program of Higher Education(Grant No.20112304120007)+2 种基金the Harbin Specialized Research Foundation for Innovation Talents(Grant No.RC2012QN009037)the Fundamental Research Funds for the Central Universities(Grant No.HEUCF041505)the State Commission of Science Technology of China(Grant No.2014DFR10010)
文摘This paper deals with the universal serial manipulator on the inverse kinematics problem of plane type,the fast working space solution method,and the obstacle avoidance path planning method. With the vector projection as the main constraint condition of the target,it proposes a general form of the inverse kinematics solution which does not depend on the robot configuration of freedom degree. By identifying the target vector direction maximum and minimum workspace boundary and determining the destination vector by thick search on the workspace boundary method,an expressing method of the polar coordinate form of work space is then introduced. Finally,according to the form of plane trajectory planning for obstacle avoidance problem,the method of solving the inverse kinematics solution of the concave and convex forms of the safe obstacle avoidance area is improved. The simulation results verify that the proposed method has feasibility and generality.
文摘A one-step synthesized Ni-Mo-S catalyst supported on SiO2 was prepared and used for hydrodesulphurization （HDS） of dibenzothiophene （DBT）, and 4,6-dimethyl-dibenzothiophene （4,6-DMDBT）, and for hydrogenation of tetralin. The catalyst showed relatively high HDS activity with complete conversion of DBT and 4,6-DMDBT at temperature of 280℃ and a constant pressure of 435 psi. The HDS conversions of DBT and 4,6- DMDBT increased with increasing temperature and pressure, and decreasing liquid hourly space velocity （LHSV）. The HDS of DBT proceeded mostly through the direct desulphurization （DDS） pathway whereas that of 4,6-DMDBT occurred mainly through the hydrogenation- desulphurization （HYD） pathway. Although the catalyst showed up to 24% hydrogenation/dehydrogenation con- version oftetralin, it had low conversion and selectivity for ring opening and contraction due to the competitive adsorption of DBT and 4,6-DMDBT and insufficient acidic sites on the catalyst surface.
