平面3-R R R并联机构的柔性杆在运动过程中产生的柔性变形会影响机构的输出精度。基于绝对节点坐标法,建立含有柔性杆、刚性动平台的平面3-R R R并联机构刚柔耦合模型,对并联机构的动态特性进行研究,获得并联机构各时刻的位姿和动平台...平面3-R R R并联机构的柔性杆在运动过程中产生的柔性变形会影响机构的输出精度。基于绝对节点坐标法,建立含有柔性杆、刚性动平台的平面3-R R R并联机构刚柔耦合模型,对并联机构的动态特性进行研究,获得并联机构各时刻的位姿和动平台质心运动轨迹。结果表明,柔性杆的弹性变形使动平台不能按照预期的轨迹运行。建立柔性杆局部坐标系,得到了柔性杆中点处挠度值,发现主动杆的弯曲变形远大于从动杆,柔性杆对机构输出精度的影响主要由主动杆产生。仿真结果可以为机构的设计和优化提供理论依据。展开更多
RS-3-chloro-2-oxy-propyltrimethylammonium-chloride 1, an important inter- mediate of carnitine and acetylcholine, has been synthesized and resolved by using R,R-tartric acid. Di-(S-3-chloro-2-oxy-propyltrimethylammoni...RS-3-chloro-2-oxy-propyltrimethylammonium-chloride 1, an important inter- mediate of carnitine and acetylcholine, has been synthesized and resolved by using R,R-tartric acid. Di-(S-3-chloro-2-oxy-propyltrimethylammonium)-R,R-tartrate 2, with optical purity of 81.76%, has been obtained. Compound 2 was characterized by IR spectroscopy, MS, NMR and X-ray diffrac- tion, and it crystallizes in orthorhombic, space group P212121, absolute structure parameter 0.56(8), with cell parameters a = 8.323(2), b = 10.203(2), c = 26.178(5) ? C16H34Cl2N2O8, Mr = 453.272, V = 2223.0(8) ?, Z = 4, Dc = 1.354 g/cm3, m = 0.335 mm-1, F(000) = 968, R = 0.0534 and wR = 0.1274 for 4376 observed reflections (I > 2s(I)). The lattice is composed of two S-3-chloro- 2-oxy-propyltrimethylammonium cations and one R,R-tartrate dianion which are arranged in separate stacks linked via hydrogen bonds.展开更多
文摘平面3-R R R并联机构的柔性杆在运动过程中产生的柔性变形会影响机构的输出精度。基于绝对节点坐标法,建立含有柔性杆、刚性动平台的平面3-R R R并联机构刚柔耦合模型,对并联机构的动态特性进行研究,获得并联机构各时刻的位姿和动平台质心运动轨迹。结果表明,柔性杆的弹性变形使动平台不能按照预期的轨迹运行。建立柔性杆局部坐标系,得到了柔性杆中点处挠度值,发现主动杆的弯曲变形远大于从动杆,柔性杆对机构输出精度的影响主要由主动杆产生。仿真结果可以为机构的设计和优化提供理论依据。
文摘RS-3-chloro-2-oxy-propyltrimethylammonium-chloride 1, an important inter- mediate of carnitine and acetylcholine, has been synthesized and resolved by using R,R-tartric acid. Di-(S-3-chloro-2-oxy-propyltrimethylammonium)-R,R-tartrate 2, with optical purity of 81.76%, has been obtained. Compound 2 was characterized by IR spectroscopy, MS, NMR and X-ray diffrac- tion, and it crystallizes in orthorhombic, space group P212121, absolute structure parameter 0.56(8), with cell parameters a = 8.323(2), b = 10.203(2), c = 26.178(5) ? C16H34Cl2N2O8, Mr = 453.272, V = 2223.0(8) ?, Z = 4, Dc = 1.354 g/cm3, m = 0.335 mm-1, F(000) = 968, R = 0.0534 and wR = 0.1274 for 4376 observed reflections (I > 2s(I)). The lattice is composed of two S-3-chloro- 2-oxy-propyltrimethylammonium cations and one R,R-tartrate dianion which are arranged in separate stacks linked via hydrogen bonds.
