The potassium terbium polyphosphate crystal KTb（PO3）4 has been synthesized using a high temperature solution reaction method. The structure and composition were characterized by single-crystal X-ray diffraction, pow...The potassium terbium polyphosphate crystal KTb（PO3）4 has been synthesized using a high temperature solution reaction method. The structure and composition were characterized by single-crystal X-ray diffraction, powder X-ray diffraction and elemental analysis. The compound crystallizes in the monoclinic space group P21/n with a=10.3182（6）, b=8.9129（5）, c=10.7940（6） , β=105.993（1）o, V=954.3 3, Z=4, Mr=513.91, Dc=3.577 g/cm3, μ=8.585 mm（-1）, F（000）=960, S=0.955,（Δρ）max=1.380,（Δρ）min=–3.428 e/3, the final R=0.0301 and w R=0.0400 for 2301 observed reflections with I 〉 2σ（I）. In addition, pure powder of isostructural Rb Tb（PO3）4 was synthesized in order to investigate the optical property. Photoluminescence measurements show that both crystals ATb（PO3）4（A=K（1）, Rb（2）） are promising candidates to become solid-state visible green light-emitting sources.展开更多
Previously,many studies have illustrated corner blend problem with different parameter curves.Only a few of them take a Pythagorean-hodograph(PH)curve as the transition arc,let alone corresponding real-time interpolat...Previously,many studies have illustrated corner blend problem with different parameter curves.Only a few of them take a Pythagorean-hodograph(PH)curve as the transition arc,let alone corresponding real-time interpolation methods.In this paper,an integrated corner-transition mixing-interpolation-based scheme(ICMS)is proposed,considering transition error and machine tool kinematics.Firstly,the ICMS smooths the sharp corners in a linear path through blending the linear path with G3 continuous PH transition curves.To obtain optimal PH transition curves globally,the problem of corner smoothing is formulated as an optimization problem with constraints.In order to improve optimization efficiency,the transition error constraint is deduced analytically,so is the curvature extreme of each transition curve.After being blended with PH transition curves,a linear path has become a blend curve.Secondly,the ICMS adopts a novel mixed interpolator to process this kind of blend curves by considering machine tool kinematics.The mixed interpolator can not only implement jerk-limited feedrate scheduling with critical points detection,but also realize self-switching of two interpolation modes.Finally,two patterns are machined with a carving platform based on ICMS.Experiment l results show the effectiveness of ICMS.展开更多
基金Supported by the National Natural Science Foundation of China(No.20901066)the Natural Science Foundation of Yunnan Province(No.2012FB122)+3 种基金the Education Science Foundation of Yunnan Province(No.2013Z050)the Science Foundation of State Key Laboratory of Structural Chemistry(No.20140012)Training Program for Young Academic and Technical Leader in Yunnan Provincethe Science Foundation of Key Laboratory of Micro-and Nano-materials and Technology in Yunnan Province(No.ZZ2016002)
文摘The potassium terbium polyphosphate crystal KTb（PO3）4 has been synthesized using a high temperature solution reaction method. The structure and composition were characterized by single-crystal X-ray diffraction, powder X-ray diffraction and elemental analysis. The compound crystallizes in the monoclinic space group P21/n with a=10.3182（6）, b=8.9129（5）, c=10.7940（6） , β=105.993（1）o, V=954.3 3, Z=4, Mr=513.91, Dc=3.577 g/cm3, μ=8.585 mm（-1）, F（000）=960, S=0.955,（Δρ）max=1.380,（Δρ）min=–3.428 e/3, the final R=0.0301 and w R=0.0400 for 2301 observed reflections with I 〉 2σ（I）. In addition, pure powder of isostructural Rb Tb（PO3）4 was synthesized in order to investigate the optical property. Photoluminescence measurements show that both crystals ATb（PO3）4（A=K（1）, Rb（2）） are promising candidates to become solid-state visible green light-emitting sources.
基金supported by the National Natural Science Foundation of China under Grant No.61573378supports from Henan Province Programs for Science and Technology Development under Grant No.212102210391Anyang Institute of Technology Research and Cultivation Fund under Grant No.YPY2020012。
文摘Previously,many studies have illustrated corner blend problem with different parameter curves.Only a few of them take a Pythagorean-hodograph(PH)curve as the transition arc,let alone corresponding real-time interpolation methods.In this paper,an integrated corner-transition mixing-interpolation-based scheme(ICMS)is proposed,considering transition error and machine tool kinematics.Firstly,the ICMS smooths the sharp corners in a linear path through blending the linear path with G3 continuous PH transition curves.To obtain optimal PH transition curves globally,the problem of corner smoothing is formulated as an optimization problem with constraints.In order to improve optimization efficiency,the transition error constraint is deduced analytically,so is the curvature extreme of each transition curve.After being blended with PH transition curves,a linear path has become a blend curve.Secondly,the ICMS adopts a novel mixed interpolator to process this kind of blend curves by considering machine tool kinematics.The mixed interpolator can not only implement jerk-limited feedrate scheduling with critical points detection,but also realize self-switching of two interpolation modes.Finally,two patterns are machined with a carving platform based on ICMS.Experiment l results show the effectiveness of ICMS.
