As an industrial byproduct of oil refining,furfural extract oil from reduced-pressure route Ⅱ with high aromatic content was used to prepare heat-resistant condensed polynuclear aromatic（COPNA） resin for the first ...As an industrial byproduct of oil refining,furfural extract oil from reduced-pressure route Ⅱ with high aromatic content was used to prepare heat-resistant condensed polynuclear aromatic（COPNA） resin for the first time.The basic properties of furfural extract oil and the resultant COPNA resin were characterized by infrared spectroscopy（FT-IR）,nuclear magnetic resonance spectroscopy（1H-NMR）,thermogravimetric analysis（TGA） and elemental analysis（EA）.The result showed that heat treated furfural extract oil was successfully used for the synthesis of heat-resistant COPNA resin.The average structural parameters of raw materials and prepared resin were calculated by the improved Brown-Ladner method,and the averaged molecular structure of the resin was obtained.The reaction mechanism for the synthesis of COPNA resin was suggested as an acid-catalyzed positive ion type polymerization.展开更多
This study reports a new weakly alkaline slurry for copper chemical mechanical planarization （CMP）, it can achieve a high planarization efficiency at a reduced down pressure of 1.0 psi. The slurry is studied through...This study reports a new weakly alkaline slurry for copper chemical mechanical planarization （CMP）, it can achieve a high planarization efficiency at a reduced down pressure of 1.0 psi. The slurry is studied through the polish rate, planarization, copper surface roughness and stability. The copper polishing experiment result shows that the polish rate can reach 10032 A/rain. From the multi-layers copper CMP test, a good result is obtained, that is a big step height （10870 A） that can be eliminated in just 35 s, and the copper root mean square surface roughness （sq） is very low （〈 1 rim）. Apart from this, compared with the alkaline slurry researched before, it has a good progress on stability of copper polishing rate, stable for 12 h at least. All the results presented here are relevant for further developments in the area of copper CMP.展开更多
Cam-rotor vane motor(CRVM) is one of the new continuous hydraulic servo motors with the characteristics of no pulsation of instantaneous flow rate and output torque,small volume and rotating inertia.It is one of the a...Cam-rotor vane motor(CRVM) is one of the new continuous hydraulic servo motors with the characteristics of no pulsation of instantaneous flow rate and output torque,small volume and rotating inertia.It is one of the appropriate actuators for hydraulic servo system which has good dynamic and steady-state performance requirements.The ideal output torque of CRVM is pulseless,but the actual output torque of CRVM is pulsating.This is caused by the disturbing torque of contact components,especially the friction between vane and cam-rotor.In order to get better performance of CRVM,which means more stable output torque and smaller disturbing torque,we discuss four kinds of vane end faces(VEFs).Analytic formulae of the normal contact force and the disturbing torque caused by the vane are derived from systematical force analysis.The normal contact force and the disturbing torque vary through a period under different VEF,and the reduced oil pressure is simulated in this paper.The simulation shows that the VEF with the proper round and reduced oil pressure can significantly decrease the disturbing torque and get better servo performance.The experiment results verify the correctness of the theoretical analysis and simulation.展开更多
基金financially supported by the National Natural Science Foundation of China (Nos. 20876176, 51172285, 51372277)the Natural Science Foundation of Shandong Province (ZR2011EL030)the Fundamental Research Funds for the Central Universities (14CX02060A)
文摘As an industrial byproduct of oil refining,furfural extract oil from reduced-pressure route Ⅱ with high aromatic content was used to prepare heat-resistant condensed polynuclear aromatic（COPNA） resin for the first time.The basic properties of furfural extract oil and the resultant COPNA resin were characterized by infrared spectroscopy（FT-IR）,nuclear magnetic resonance spectroscopy（1H-NMR）,thermogravimetric analysis（TGA） and elemental analysis（EA）.The result showed that heat treated furfural extract oil was successfully used for the synthesis of heat-resistant COPNA resin.The average structural parameters of raw materials and prepared resin were calculated by the improved Brown-Ladner method,and the averaged molecular structure of the resin was obtained.The reaction mechanism for the synthesis of COPNA resin was suggested as an acid-catalyzed positive ion type polymerization.
基金Project supported by the Special Project Items No.2 in National Long-Term Technology Development Plan,China(No.2009ZX02308)the Hebei Natural Science Foundation of China(No.F2012202094)
文摘This study reports a new weakly alkaline slurry for copper chemical mechanical planarization （CMP）, it can achieve a high planarization efficiency at a reduced down pressure of 1.0 psi. The slurry is studied through the polish rate, planarization, copper surface roughness and stability. The copper polishing experiment result shows that the polish rate can reach 10032 A/rain. From the multi-layers copper CMP test, a good result is obtained, that is a big step height （10870 A） that can be eliminated in just 35 s, and the copper root mean square surface roughness （sq） is very low （〈 1 rim）. Apart from this, compared with the alkaline slurry researched before, it has a good progress on stability of copper polishing rate, stable for 12 h at least. All the results presented here are relevant for further developments in the area of copper CMP.
基金the National Natural Science Foundation of China(Nos.51275288 and 51375293)
文摘Cam-rotor vane motor(CRVM) is one of the new continuous hydraulic servo motors with the characteristics of no pulsation of instantaneous flow rate and output torque,small volume and rotating inertia.It is one of the appropriate actuators for hydraulic servo system which has good dynamic and steady-state performance requirements.The ideal output torque of CRVM is pulseless,but the actual output torque of CRVM is pulsating.This is caused by the disturbing torque of contact components,especially the friction between vane and cam-rotor.In order to get better performance of CRVM,which means more stable output torque and smaller disturbing torque,we discuss four kinds of vane end faces(VEFs).Analytic formulae of the normal contact force and the disturbing torque caused by the vane are derived from systematical force analysis.The normal contact force and the disturbing torque vary through a period under different VEF,and the reduced oil pressure is simulated in this paper.The simulation shows that the VEF with the proper round and reduced oil pressure can significantly decrease the disturbing torque and get better servo performance.The experiment results verify the correctness of the theoretical analysis and simulation.
