Ice nucleation and accretion on structural surfaces are sources of major safety and operational concerns in many industries including aviation and renewable energy.Common methods for tackling these are active ones suc...Ice nucleation and accretion on structural surfaces are sources of major safety and operational concerns in many industries including aviation and renewable energy.Common methods for tackling these are active ones such as heating,ultrasound,and chemicals or passive ones such as surface coatings.In this study,we explored the ice adhesion properties of slippery coated substrates by measuring the shear forces required to remove a glaze ice block on the coated substrates.Among the studied nanostructured and nanoscale surfaces[i.e.,a superhydrophobic coating,a fluoropolymer coating,and a polydimethylsiloxane(PDMS)chain coating],the slippery omniphobic covalently attached liquid(SOCAL)surface with its flexible polymer brushes and liquid-like structure significantly reduced the ice adhesion on both glass and silicon surfaces.Further studies of the SOCAL coating on roughened substrates also demonstrated its low ice adhesion.The reduction in ice adhesion is attributed to the flexible nature of the brush-like structures of PDMS chains,allowing ice to detach easily.展开更多
本研究从权利公平、机会公平和规则公平三个方面分析了当前我国的社会公平感现状,探讨了社会经济地位和社会比较对公平感的影响。数据来源于2017年社会心态调查(CASS-INTELLVISION Social Mentality Survey)的22669个居民数据。结果发现...本研究从权利公平、机会公平和规则公平三个方面分析了当前我国的社会公平感现状,探讨了社会经济地位和社会比较对公平感的影响。数据来源于2017年社会心态调查(CASS-INTELLVISION Social Mentality Survey)的22669个居民数据。结果发现,调查对象的社会公平感普遍偏低,机会公平最受质疑。社会公平感的影响因素分析结果更多支持“局部比较理论”而不是“结构决定论”,主观社会阶层可以提升社会公平感,积极的社会比较和对比较结果的合理性认知可以提升社会公平。客观社会经济地位与社会公平感之间的关系取决于社会比较的结果,当社会比较不如他人的时候,客观社会经济地位和社会公平感之间负相关。展开更多
目的了解妊娠早期妇女心理状况及相关影响因素。方法采用焦虑自评量表、抑郁自评量表、社会支持评定量表对508名妊娠早期妇女进行调查。结果社会支持评定量表各维度得分均与孕妇心理状况高度相关。计划怀孕的孕妇焦虑与抑郁的发生率明...目的了解妊娠早期妇女心理状况及相关影响因素。方法采用焦虑自评量表、抑郁自评量表、社会支持评定量表对508名妊娠早期妇女进行调查。结果社会支持评定量表各维度得分均与孕妇心理状况高度相关。计划怀孕的孕妇焦虑与抑郁的发生率明显低于非计划怀孕的孕妇（23.95% vs 40.63%，10.53% vs 22.66%），差异有统计学意义（χ2=12.002，P〈0.01；χ2=13.167，P〈0.01）。有先兆流产史的孕妇焦虑与抑郁的发生率明显高于无先兆流产史者（21.54% vs 12.12%，37.97% vs 26.34%），差异有统计学意义（χ2=4.465，P〈0.05；χ2=5.020，P〈0.05）。结论影响妊娠早期妇女心理状况的主要因素有低社会支持、计划外妊娠、有先兆流产史。展开更多
The problem of contact line pinning on surfaces is pervasive and contributes to problems from ring stains to ice formation.Here we provide a single conceptual framework for interfacial strategies encompassing five str...The problem of contact line pinning on surfaces is pervasive and contributes to problems from ring stains to ice formation.Here we provide a single conceptual framework for interfacial strategies encompassing five strategies for modifying the solid-liquid interface to remove pinning and increase droplet mobility.Three biomimetic strategies are included,(i)reducing the liquid-solid interfacial area inspired by the Lotus effect,(ii)converting the liquid-solid contact to a solid-solid contact by the formation of a liquid marble inspired by how galling aphids remove honeydew,and(iii)converting the liquid-solid interface to a liquid-lubricant contact by the use of a lubricant impregnated surface inspired by the Nepenthes Pitcher plant.Two further strategies are,(iv)converting the liquid-solid contact to a liquid-vapor contact by using the Leidenfrost effect,and(v)converting the contact to a liquid-liquid-like contact using slippery omniphobic covalent attachment of a liquid-like coating(SOCAL).Using these approaches,we explain how surfaces can be designed to have smart functionality whilst retaining the mobility of contact lines and droplets.Furthermore,we show how droplets can evaporate at constant contact angle,be positioned using a Cheerios effect,transported by boundary reconfiguration in an energy invariant manner,and drive the rotation of solid components in a Leidenfrost heat engine.Our conceptual framework enables the rationale design of surfaces which are slippery to liquids and is relevant to a diverse range of applications.展开更多
基金supported by the Engineering and Physical Sciences Research Council(EPSRC)of the U.K.(Grant No.EP/P018998/1)the Acoustofluidics Special Interest Group of the UK Fluids Network(Grant No.EP/N032861/1)the EPSRC Centre for Doctoral Training in Renewable Energy Northeast Universities(ReNU)(Grant No.EP/S023836/1).
文摘Ice nucleation and accretion on structural surfaces are sources of major safety and operational concerns in many industries including aviation and renewable energy.Common methods for tackling these are active ones such as heating,ultrasound,and chemicals or passive ones such as surface coatings.In this study,we explored the ice adhesion properties of slippery coated substrates by measuring the shear forces required to remove a glaze ice block on the coated substrates.Among the studied nanostructured and nanoscale surfaces[i.e.,a superhydrophobic coating,a fluoropolymer coating,and a polydimethylsiloxane(PDMS)chain coating],the slippery omniphobic covalently attached liquid(SOCAL)surface with its flexible polymer brushes and liquid-like structure significantly reduced the ice adhesion on both glass and silicon surfaces.Further studies of the SOCAL coating on roughened substrates also demonstrated its low ice adhesion.The reduction in ice adhesion is attributed to the flexible nature of the brush-like structures of PDMS chains,allowing ice to detach easily.
文摘本研究从权利公平、机会公平和规则公平三个方面分析了当前我国的社会公平感现状,探讨了社会经济地位和社会比较对公平感的影响。数据来源于2017年社会心态调查(CASS-INTELLVISION Social Mentality Survey)的22669个居民数据。结果发现,调查对象的社会公平感普遍偏低,机会公平最受质疑。社会公平感的影响因素分析结果更多支持“局部比较理论”而不是“结构决定论”,主观社会阶层可以提升社会公平感,积极的社会比较和对比较结果的合理性认知可以提升社会公平。客观社会经济地位与社会公平感之间的关系取决于社会比较的结果,当社会比较不如他人的时候,客观社会经济地位和社会公平感之间负相关。
文摘目的了解妊娠早期妇女心理状况及相关影响因素。方法采用焦虑自评量表、抑郁自评量表、社会支持评定量表对508名妊娠早期妇女进行调查。结果社会支持评定量表各维度得分均与孕妇心理状况高度相关。计划怀孕的孕妇焦虑与抑郁的发生率明显低于非计划怀孕的孕妇（23.95% vs 40.63%，10.53% vs 22.66%），差异有统计学意义（χ2=12.002，P〈0.01；χ2=13.167，P〈0.01）。有先兆流产史的孕妇焦虑与抑郁的发生率明显高于无先兆流产史者（21.54% vs 12.12%，37.97% vs 26.34%），差异有统计学意义（χ2=4.465，P〈0.05；χ2=5.020，P〈0.05）。结论影响妊娠早期妇女心理状况的主要因素有低社会支持、计划外妊娠、有先兆流产史。
基金Many co-workers contributed to the work described and to development of the ideas including,Dr.Prashant Agrawal,Mr Steven Armstrong,Dr.Linzi Dodd,Dr.Jian(James)H.Guan,Dr.Elfego Ruiz-Gutierrez,Dr.Halim Kusumaatmaja,Dr.Bethany V.Orme,Professor Khellil Sefiane,Dr.Ciro Semprebon,Professor Dominic Vella,Professor David Wood and Dr.Ben B.Xu.This work was financially supported in part by the UK Engineering&Physical Sciences Research Council(EPSRC grants EP/P005896/1 and EP/P005705/1)and Reece Innovation Ltd.
文摘The problem of contact line pinning on surfaces is pervasive and contributes to problems from ring stains to ice formation.Here we provide a single conceptual framework for interfacial strategies encompassing five strategies for modifying the solid-liquid interface to remove pinning and increase droplet mobility.Three biomimetic strategies are included,(i)reducing the liquid-solid interfacial area inspired by the Lotus effect,(ii)converting the liquid-solid contact to a solid-solid contact by the formation of a liquid marble inspired by how galling aphids remove honeydew,and(iii)converting the liquid-solid interface to a liquid-lubricant contact by the use of a lubricant impregnated surface inspired by the Nepenthes Pitcher plant.Two further strategies are,(iv)converting the liquid-solid contact to a liquid-vapor contact by using the Leidenfrost effect,and(v)converting the contact to a liquid-liquid-like contact using slippery omniphobic covalent attachment of a liquid-like coating(SOCAL).Using these approaches,we explain how surfaces can be designed to have smart functionality whilst retaining the mobility of contact lines and droplets.Furthermore,we show how droplets can evaporate at constant contact angle,be positioned using a Cheerios effect,transported by boundary reconfiguration in an energy invariant manner,and drive the rotation of solid components in a Leidenfrost heat engine.Our conceptual framework enables the rationale design of surfaces which are slippery to liquids and is relevant to a diverse range of applications.
