慢性疼痛严重威胁着老年人的身心健康，其患病率之高令人惊讶。据澳大利亚国立衰老研究所（National Aging Research Institution，Australia）报道，在社区居住的老年人中有50％患有慢性疼痛；而在敬老院居住的老年人中慢性疼痛的患病...慢性疼痛严重威胁着老年人的身心健康，其患病率之高令人惊讶。据澳大利亚国立衰老研究所（National Aging Research Institution，Australia）报道，在社区居住的老年人中有50％患有慢性疼痛；而在敬老院居住的老年人中慢性疼痛的患病率高达80％。遗憾的是老年人的慢性疼痛没有得到足够重视和合理治疗。疼痛治疗的欠缺常常会给老年人的健康带来严重的后果，导致各种生理功能的减弱或丧失，活动减少，日常生活严重依赖他人帮助。展开更多
Surface moisture or humidity impacting the lubrication property is a ubiquitous phenomenon in tribological systems,which is demonstrated by a combination of molecular dynamics(MD)simulation and experiment for the orga...Surface moisture or humidity impacting the lubrication property is a ubiquitous phenomenon in tribological systems,which is demonstrated by a combination of molecular dynamics(MD)simulation and experiment for the organic friction modifier(OFM)-containing lubricant.The stearic acid and poly-α-olefin 4cSt(PAO4)were chosen as the OFM and base oil molecules,respectively.The physical adsorption indicates that on the moist surface water molecules are preferentially adsorbed on friction surface,and even make OFM adsorption film thoroughly leave surface and mix with base oil.In shear process,the adsorption of water film and desorption OFM film are further enhanced,particularly under higher shear rate.The simulated friction coefficient(that is proportional to shear rate)increases firstly and then decreases with thickening water film,in good agreement with experiments,while the slip length shows a contrary change.The wear increases with humidity due to tribochemistry revealing the continuous formation and removal of Si–O–Si network.The tribological discrepancy of OFM-containing lubricant in dry and humid conditions is attributed to the slip plane’s transformation from the interface between OFM adsorption film and lubricant bulk to the interface between adsorbed water films.This work provides a new thought to understand the boundary lubrication and failure of lubricant in humid environments,likely water is not always harmful in oil lubrication systems.展开更多
文摘慢性疼痛严重威胁着老年人的身心健康，其患病率之高令人惊讶。据澳大利亚国立衰老研究所（National Aging Research Institution，Australia）报道，在社区居住的老年人中有50％患有慢性疼痛；而在敬老院居住的老年人中慢性疼痛的患病率高达80％。遗憾的是老年人的慢性疼痛没有得到足够重视和合理治疗。疼痛治疗的欠缺常常会给老年人的健康带来严重的后果，导致各种生理功能的减弱或丧失，活动减少，日常生活严重依赖他人帮助。
基金the financial support from the National Natural Science Foundation of China(52105210)Project funded by China Postdoctoral Science Foundation(2022M712593)+1 种基金Research Fund of the State Key Laboratory of Solidification Processing(NPU)(2021-TS-06)Zhejiang Provincial Natural Science Foundation of China(Key Program,Grant No.LZ21A020001).
文摘Surface moisture or humidity impacting the lubrication property is a ubiquitous phenomenon in tribological systems,which is demonstrated by a combination of molecular dynamics(MD)simulation and experiment for the organic friction modifier(OFM)-containing lubricant.The stearic acid and poly-α-olefin 4cSt(PAO4)were chosen as the OFM and base oil molecules,respectively.The physical adsorption indicates that on the moist surface water molecules are preferentially adsorbed on friction surface,and even make OFM adsorption film thoroughly leave surface and mix with base oil.In shear process,the adsorption of water film and desorption OFM film are further enhanced,particularly under higher shear rate.The simulated friction coefficient(that is proportional to shear rate)increases firstly and then decreases with thickening water film,in good agreement with experiments,while the slip length shows a contrary change.The wear increases with humidity due to tribochemistry revealing the continuous formation and removal of Si–O–Si network.The tribological discrepancy of OFM-containing lubricant in dry and humid conditions is attributed to the slip plane’s transformation from the interface between OFM adsorption film and lubricant bulk to the interface between adsorbed water films.This work provides a new thought to understand the boundary lubrication and failure of lubricant in humid environments,likely water is not always harmful in oil lubrication systems.
