Stable lubrication is essential to slider/disk interface of computer hard disk drive. Inert lubricant perfluoropolyether (PFPE) on magnetic hard disk in computer is still prone to catalytic decomposition by Al_2O_3, w...Stable lubrication is essential to slider/disk interface of computer hard disk drive. Inert lubricant perfluoropolyether (PFPE) on magnetic hard disk in computer is still prone to catalytic decomposition by Al_2O_3, which is one of the materials in slider. A partial fluorinated hexaphenoxy cyclotriphosphazene chemical, X-1 P, was analyzed to research on its function to reduce the cata- lytic decomposition of lubricant. The surface free energy of X-1 P coated on head surface was also investigated. Contact start-stop (CSS) tester was employed to investigate the reflow effective of X-1 P on lubricant PFPE. Results indicate that thermal stability and reflow of lubricant will be im- proved in the presence of X-1 P on the slider.展开更多
The recent discoveries of pulsed X-ray emission from three ultraluminous X-ray （ULX） sources have finally enabled us to recognize a subclass within the ULX class： the great pretenders, neutron stars （NSs） that ap...The recent discoveries of pulsed X-ray emission from three ultraluminous X-ray （ULX） sources have finally enabled us to recognize a subclass within the ULX class： the great pretenders, neutron stars （NSs） that appear to emit X-ray radiation at isotropic luminosities Lx = 7 × 10^39 erg s-1 _ 1 ×10^41 erg s-i only because their emissions are strongly beamed toward our direction and our sight lines are offset by only a few degrees from their magnetic-dipole axes. The three known pretenders appear to be stronger emitters than the presumed black holes of the ULX class, such as Holmberg II ＆ IX X-1, IC10 X-1 and NGC 300 X-1. For these three NSs, we have adopted a single reasonable assumption, that their brightest observed outbursts unfold at the Eddington rate, and we have calculated both their propeller states and their surface magnetic-field magnitudes. We find that the results are not at all different from those recently obtained for the Magellanic Be/X-ray pulsars： the three NSs reveal modest magnetic fields of about 0.3-0.4TG and beamed propeller-line X-ray luminosities of 1036 - 1037 erg s-1, substantially below the Eddington limit.展开更多
文摘Stable lubrication is essential to slider/disk interface of computer hard disk drive. Inert lubricant perfluoropolyether (PFPE) on magnetic hard disk in computer is still prone to catalytic decomposition by Al_2O_3, which is one of the materials in slider. A partial fluorinated hexaphenoxy cyclotriphosphazene chemical, X-1 P, was analyzed to research on its function to reduce the cata- lytic decomposition of lubricant. The surface free energy of X-1 P coated on head surface was also investigated. Contact start-stop (CSS) tester was employed to investigate the reflow effective of X-1 P on lubricant PFPE. Results indicate that thermal stability and reflow of lubricant will be im- proved in the presence of X-1 P on the slider.
基金DMC,SGTL and RC were supported by NASA grant NNX14-AF77GDK was supported by a NASA ADAP grant
文摘The recent discoveries of pulsed X-ray emission from three ultraluminous X-ray （ULX） sources have finally enabled us to recognize a subclass within the ULX class： the great pretenders, neutron stars （NSs） that appear to emit X-ray radiation at isotropic luminosities Lx = 7 × 10^39 erg s-1 _ 1 ×10^41 erg s-i only because their emissions are strongly beamed toward our direction and our sight lines are offset by only a few degrees from their magnetic-dipole axes. The three known pretenders appear to be stronger emitters than the presumed black holes of the ULX class, such as Holmberg II ＆ IX X-1, IC10 X-1 and NGC 300 X-1. For these three NSs, we have adopted a single reasonable assumption, that their brightest observed outbursts unfold at the Eddington rate, and we have calculated both their propeller states and their surface magnetic-field magnitudes. We find that the results are not at all different from those recently obtained for the Magellanic Be/X-ray pulsars： the three NSs reveal modest magnetic fields of about 0.3-0.4TG and beamed propeller-line X-ray luminosities of 1036 - 1037 erg s-1, substantially below the Eddington limit.
文摘纳米技术在过去的几年里取得了巨大的进展.关注其两个主要方面:纳米级的薄膜润滑与纳米表面改性研究.薄膜润滑(thinfilmlubrication,TFL)的研究进展包括薄膜润滑测试技术、薄膜润滑的膜厚 工况相关特性、机理探索以及数学计算预测模型等方面.介绍了降低极尖沉降(pole tip recession,PTR)的技术,使用含有氮磷的环状化合物———X 1P来提高润滑剂的热稳定性的方法,以及使用纳米粒子的化学机械抛光技术.这些研究成果揭示了现代纳米技术的一些重要特征.
