First,screw theory,product of exponential formulas and Jacobian matrix are introduced.Then definitions are given about active force wrench,inertial force wrench,partial velocity twist,generalized active force,and gene...First,screw theory,product of exponential formulas and Jacobian matrix are introduced.Then definitions are given about active force wrench,inertial force wrench,partial velocity twist,generalized active force,and generalized inertial force according to screw theory.After that Kane dynamic equations based on screw theory for open-chain manipulators have been derived. Later on how to compute the partial velocity twist by geometrical method is illustrated. Finally the correctness of conclusions is verified by example.展开更多
The geometry and the energy of conformers of PnHn+2(n=2-9) have been studied with PM3 method. It is concluded that gauche interaction between adjacent lone electron pairs and gauche interaction between P-H bond with a...The geometry and the energy of conformers of PnHn+2(n=2-9) have been studied with PM3 method. It is concluded that gauche interaction between adjacent lone electron pairs and gauche interaction between P-H bond with adjacent P-P bond are important for predicting the stable conformer of open-chain phosphoanes.展开更多
Four solid complexes of alkaline earth picrates with N,N,N′,N′-tetraphenyl-3,6,9-trioxaundecanediamide (TTD), M (Pic)2TTD (1, M = Mg; 2, M = Ca; 3, M = Sr; 4, M = Ba), have been prepared and characterized by element...Four solid complexes of alkaline earth picrates with N,N,N′,N′-tetraphenyl-3,6,9-trioxaundecanediamide (TTD), M (Pic)2TTD (1, M = Mg; 2, M = Ca; 3, M = Sr; 4, M = Ba), have been prepared and characterized by elemental analysis, conductivity measurement, IR spectra, 1H NMR spectra and TG-DTA techniques. Crystal structure of complex 3 shows that the Sr(II) ion is 9-coordinated by five oxygen atoms from TTD and four oxygen atoms from two bidentate picrates, and the coordination polyhedron is distorted tricapped trigonal prism. TTD as a pentadentate ligand forms a right-handed helical coordination structure. The chelating helical chain has a relative fixed radius and then shows a high coordination selectivity to metal ion. The high selectivity of TTD to alkaline earth ions is explained elementarily from the special coordination structures.展开更多
外卖配取过程中实时订单的不断插入具有强烈的不确定性,需持续进行滚动优化以动态更新配取路径。动态条件下,有效地合并取餐与配送作业(dynamic order combination,DOC)可显著减少冗余路径。本文将动态配取路径规划问题转化为变长开放...外卖配取过程中实时订单的不断插入具有强烈的不确定性,需持续进行滚动优化以动态更新配取路径。动态条件下,有效地合并取餐与配送作业(dynamic order combination,DOC)可显著减少冗余路径。本文将动态配取路径规划问题转化为变长开放链滚动优化问题,并构建多目标滚动配取路径规划模型对DOC与节点排序进行集成决策。考虑滚动优化框架下紧前决策对紧后决策的调度影响,模型在兼顾配取效率和客户满意度的同时,考虑了基于look-forward的滚动调度后效性。针对该模型,本文基于NSGA-Ⅲ框架开发了多目标元启发式算法进行求解,并设计了基于插入限制规则的元胞数组解编码和混合PMX&SBX交叉方式以适应模型的复杂可行域结构。通过一系列的仿真实验,本文验证了所提出的模型和算法的有效性与优越性。展开更多
文摘First,screw theory,product of exponential formulas and Jacobian matrix are introduced.Then definitions are given about active force wrench,inertial force wrench,partial velocity twist,generalized active force,and generalized inertial force according to screw theory.After that Kane dynamic equations based on screw theory for open-chain manipulators have been derived. Later on how to compute the partial velocity twist by geometrical method is illustrated. Finally the correctness of conclusions is verified by example.
文摘The geometry and the energy of conformers of PnHn+2(n=2-9) have been studied with PM3 method. It is concluded that gauche interaction between adjacent lone electron pairs and gauche interaction between P-H bond with adjacent P-P bond are important for predicting the stable conformer of open-chain phosphoanes.
基金This work was supported by the National Natural Science Foundation of China(Grant No.20071015)Key Project of Science and Technology of the Ministry of Education of China(Grant No.01170)Foundation for University Key Teacher by the Ministry of Education of China.
文摘Four solid complexes of alkaline earth picrates with N,N,N′,N′-tetraphenyl-3,6,9-trioxaundecanediamide (TTD), M (Pic)2TTD (1, M = Mg; 2, M = Ca; 3, M = Sr; 4, M = Ba), have been prepared and characterized by elemental analysis, conductivity measurement, IR spectra, 1H NMR spectra and TG-DTA techniques. Crystal structure of complex 3 shows that the Sr(II) ion is 9-coordinated by five oxygen atoms from TTD and four oxygen atoms from two bidentate picrates, and the coordination polyhedron is distorted tricapped trigonal prism. TTD as a pentadentate ligand forms a right-handed helical coordination structure. The chelating helical chain has a relative fixed radius and then shows a high coordination selectivity to metal ion. The high selectivity of TTD to alkaline earth ions is explained elementarily from the special coordination structures.
文摘外卖配取过程中实时订单的不断插入具有强烈的不确定性,需持续进行滚动优化以动态更新配取路径。动态条件下,有效地合并取餐与配送作业(dynamic order combination,DOC)可显著减少冗余路径。本文将动态配取路径规划问题转化为变长开放链滚动优化问题,并构建多目标滚动配取路径规划模型对DOC与节点排序进行集成决策。考虑滚动优化框架下紧前决策对紧后决策的调度影响,模型在兼顾配取效率和客户满意度的同时,考虑了基于look-forward的滚动调度后效性。针对该模型,本文基于NSGA-Ⅲ框架开发了多目标元启发式算法进行求解,并设计了基于插入限制规则的元胞数组解编码和混合PMX&SBX交叉方式以适应模型的复杂可行域结构。通过一系列的仿真实验,本文验证了所提出的模型和算法的有效性与优越性。
