To improve the efficiency of CNC machining, assumptive transit circular arc is used to contour two adjacent moves together on the comer to make smooth paths. The radios of transit circular arc can be adjusted with con...To improve the efficiency of CNC machining, assumptive transit circular arc is used to contour two adjacent moves together on the comer to make smooth paths. The radios of transit circular arc can be adjusted with contour accuracy, and the feed rate on the corner can be controlled through limiting the maximum feed rate of transit circular arc segment. A look-ahead algorithm for a series of moves is proposed for speed adjustment in advance, which avoids the occurrence of overload of cutting tool on the comer and reduces the servo track error of parts on the corner or of circular arc move. Equivalent trapezoidal velocity profile is used to analyze the speed of S-curve velocity profile and work out its accurate interpolation, which overcomes the disadvantage of looking up table to calculate feed rate approximately, hence high accuracy and fine surface quality can be obtained while the machining speed is high. The proposed methods can meet the requirements of real-time analysis of high-speed machining. The presented algorithm is effective and has been adopted by CNC system of newly developed high-speed milling machine.展开更多
A new fluorescence silver nanosensor assisted by surfactant has been synthesized and applied to ultra trace nickel determination. Operational variables which influence nanomaterial synthesis have been studied and opti...A new fluorescence silver nanosensor assisted by surfactant has been synthesized and applied to ultra trace nickel determination. Operational variables which influence nanomaterial synthesis have been studied and optimized. Synthesis was very fast and simple using non polluting solvents; silver chemical reduction was carried out at room temperature. Spectroscopic studies were carried out in order to assure the uniformed of nanomaterial obtained. Fluorescent signal of silver nanoparticles resulted enhanced in presence of Ni（II）. At optimal experimental conditions, a detection limit of 0.036 pg＇L1 and quantification limit 0.12 pg＇L~ were obtained. The calibration sensitivity was 2 x 1014 L.pg-l.cm1 for the new methodology, with a range of linearity of six orders of magnitude between 0.12 and 2.93 × 10^5 pg L^-1. The tolerance levels for potential interferent ions were studied with good results. The proposed methodology represents a promising approach for Ni（II） traces quantification due to its low operation cost, simplicity of instrumentation, high sampling speed and non-polluting solvents.展开更多
基金Sponsored by the National Excellent Young Teacher Encouragement Plan of China
文摘To improve the efficiency of CNC machining, assumptive transit circular arc is used to contour two adjacent moves together on the comer to make smooth paths. The radios of transit circular arc can be adjusted with contour accuracy, and the feed rate on the corner can be controlled through limiting the maximum feed rate of transit circular arc segment. A look-ahead algorithm for a series of moves is proposed for speed adjustment in advance, which avoids the occurrence of overload of cutting tool on the comer and reduces the servo track error of parts on the corner or of circular arc move. Equivalent trapezoidal velocity profile is used to analyze the speed of S-curve velocity profile and work out its accurate interpolation, which overcomes the disadvantage of looking up table to calculate feed rate approximately, hence high accuracy and fine surface quality can be obtained while the machining speed is high. The proposed methods can meet the requirements of real-time analysis of high-speed machining. The presented algorithm is effective and has been adopted by CNC system of newly developed high-speed milling machine.
文摘A new fluorescence silver nanosensor assisted by surfactant has been synthesized and applied to ultra trace nickel determination. Operational variables which influence nanomaterial synthesis have been studied and optimized. Synthesis was very fast and simple using non polluting solvents; silver chemical reduction was carried out at room temperature. Spectroscopic studies were carried out in order to assure the uniformed of nanomaterial obtained. Fluorescent signal of silver nanoparticles resulted enhanced in presence of Ni（II）. At optimal experimental conditions, a detection limit of 0.036 pg＇L1 and quantification limit 0.12 pg＇L~ were obtained. The calibration sensitivity was 2 x 1014 L.pg-l.cm1 for the new methodology, with a range of linearity of six orders of magnitude between 0.12 and 2.93 × 10^5 pg L^-1. The tolerance levels for potential interferent ions were studied with good results. The proposed methodology represents a promising approach for Ni（II） traces quantification due to its low operation cost, simplicity of instrumentation, high sampling speed and non-polluting solvents.
