仿生制备氧化锌纳米棒阵列超疏水表面

通过模仿荷叶表面微观结构和表面化学成分的方法,以玻璃为基底在溶液中生长ZnO纳米棒并经表面低自由能化修饰,从而成功制备了ZnO纳米棒阵列超疏水表面.经接触角测量仪表征,该超疏水表面静态水接触角为156°,扫描电镜分析表明所制备的ZnO纳米棒均具有100 nm左右的直径,这种微纳米的复合结构是赋予材料表面超疏水性能的主要因素.最后采用Cassie模型对该超疏水表面的超疏水性能进行了理论分析.     

蝴蝶翅表面多级微/纳结构疏水模型及耦合机理

使用扫描电子显微镜(SEM)、接触角测量仪和红外光谱仪(FT-IR),观测了27种蝴蝶翅表面的微观结构、复合浸润性和化学成分.利用Cassie方程建立了蝴蝶翅表面微/纳结构疏水模型,从生物耦合角度探讨了疏水机理.结果表明,蝴蝶翅表面由天然疏水材料组成,具有复杂的多级微/纳结构,包括一级结构(微米级鳞片)、二级结构(纳米级纵肋和横桥)和三级结构(纳米级突起).翅表面具有高疏水性(接触角138°~157°)和低黏附性(滚动角1°~3°).翅表面微观形貌和自清洁性具有显著的各向异性.这种特殊的复合浸润性是材料耦元与结构耦元耦合作用的结果.微米级鳞片的宽度越小、间距越大,纳米级纵肋的高度越小、宽度越小、间距越大,翅表面疏水性越强.研究结果有助于进一步流调结果揭示生物表面的疏水机理,为智能界面材料的仿生设计和制备提供启示.     

氧化还原法刻蚀制备铜基超疏水表面

通过三氯化铁和铜的氧化还原反应,在铜基材料上制备了具有一定粗糙度的微结构表面。该表面使用月桂酸进行表面处理后,表现出优异的超疏水性能。水在该表面上的接触角可达161.6°。表面微结构和超疏水性能受刻蚀时间的影响较大。随着刻蚀时间的增加,表面上的微粗糙结构开始逐渐形成并增大,此过程对应的水的接触角不断增加,到一定程度后,逐渐趋于稳定。进一步考察了刻蚀剂的浓度、修饰剂的种类、浓度和时间等条件对于该表面超疏水性能的影响。结果表明,反应和修饰条件对铜表面的表面润湿性能具有明显的影响。     

蝴蝶翅表面的多级复合结构和疏水性

使用扫描电镜和视频光学接触角测量仪研究了22种蝴蝶翅表面的多级复合结构和疏水性。一级结构为微米级鳞片,鳞片密度为101~280个/mm2,长65~135μm,宽35~85μm,间距48~112μm。二级结构为鳞片表面的亚微米级纵肋和横向连接。三级结构为纵肋和横向连接上的纳米级突起。蝴蝶翅表面的蒸馏水接触角为138.2°~158.5°,属于天然疏水表面,这是翅表面化学组成与微观结构协同作用的结果。蝴蝶翅表面可为新型仿生自清洁材料的制备提供生物模板。     

采用热压-喷涂法制备PMMA超疏表面涂层

以纳米SiO_2和PMMA为原料,提出了一种以不锈钢丝网为热压模板结合喷涂法制备PMMA超疏表面的新方法.研究了热压压力和喷涂SiO_2纳米粒子浓度对表面浸润性的影响.结果表明,SiO_2纳米粒子能够明显改善PMMA表面的浸润性.在热压压力为0.5MPa、疏水性SiO_2纳米粒子质量分数为4%时,可获得最佳的超疏水涂层,涂层的接触角为164°±0.8°,滚动角小于2°.通过扫描电镜(SEM)观察了涂层表面的微观结构,发现超疏水性涂层具备规则的微纳二元结构.该表面在p H值为1~14的范围内都具有很好的超疏性能;同时,制备的超疏水涂层在空气中放置10个月以上,其表面接触角仍大于150°.     

蝴蝶翅表面的多级复合结构和疏水性

使用扫描电镜和视频光学接触角测量仪研究了22种蝴蝶翅表面的多级复合结构和疏水性。一级结构为微米级鳞片,鳞片密度为101~280个/mm2,长65~135μm,宽35~85μm,间距48~112μm。二级结构为鳞片表面的亚微米级纵肋和横向连接。三级结构为纵肋和横向连接上的纳米级突起。蝴蝶翅表面的蒸馏水接触角为138.2°~158.5°,属于天然疏水表面,这是翅表面化学组成与微观结构协同作用的结果。蝴蝶翅表面可为新型仿生自清洁材料的制备提供生物模板。     

两亲接枝共聚物PS-g-PEO膜的制备及其表面浸润性

采用模板法制备具有微纳米复合结构的聚苯乙烯接枝聚氧乙烯(PS-g-PEO)共聚物膜.将其与滴涂法制备的平滑膜进行比较,考察PEO含量、表面形貌对共聚物膜表面浸润性的影响.将制备的膜进行退火及水浸泡处理后测其接触角变化.结果表明:退火和水浸泡处理可使共聚物膜表面浸润性发生可逆改变,退火后共聚物膜表面接触角增大,水浸泡后接触角减小.其中退火后的PEO含量为40.9%的共聚物平滑膜进行水浸泡处理后,膜表面接触角由65.1°减小到53.3°,而对应的共聚物粗糙膜表面接触角由150.0°减小到60.9°,实现了超疏水到亲水的转变.不同处理条件下PEO链段聚集状态不同,退火及水浸泡处理使PEO链段发生翻转,导致膜表面浸润性发生可逆改变.     

超疏水锌表面的制备及其性能研究

将锌片置于盐酸和月桂酸的乙醇溶液中浸泡一段时间后,采用扫描电镜、傅里叶红外变换光谱仪、接触角测量仪分别对其表面结构、化学组成及其疏水性能进行了分析.结果表明锌片经简单浸泡处理后,其表面形成的粗糙结构和月桂酸的共同作用使其表现出很好的超疏水性能.     

涂层法制备超疏水表面及在油水分离中的应用

采用涂层法,以含硅聚四氟乙烯为成膜物质,以疏水纳米SiO2为填料,成功制备出含有微/纳米复合结构的超疏水表面.系统研究了疏水纳米SiO2和低表面能物质的含量与涂层表面水接触角的关系.采用接触角测量仪和扫描电子显微镜(SEM)分别对涂层的水接触角和表面形貌进行表征,根据国家标准分别对涂层厚度、硬度和结合力进行测试.在最佳制备条件下,该超疏水涂层水接触角153.5°,涂层厚度22μm,涂层硬度4H,结合力1级.该超疏水涂层具有自清洁及良好的油水分离性能.     

一步喷涂法制备低黏附的超疏水颗粒表面

采用硬脂酸和十八烷基三氯硅烷分别对商业来源的ZnO、TiO2和SiO2颗粒进行修饰得到相应的疏水颗粒.然后利用简单的一步喷涂法通过喷涂所制备的疏水颗粒的无水乙醇悬浮液制备自清洁型的超疏水颗粒表面.通过红外光谱(FT-IR)、X-射线光电子能谱(XPS)、X-射线粉末衍射(XRD)证明低表面能物质成功地修饰在这些氧化物表面;用扫描电镜(SEM)观察超疏水表面形貌发现表面团聚现象比较严重;用DSA100型接触角测量仪测量所制备的超疏水颗粒表面对水滴的静态接触角高达160°,滚动角小于5°,说明该表面具有良好的超疏水性能.     

Markedness and its Interpretation in Language Use

Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.     

Features of Women's language

Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women＇s language from these perspectives： pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women＇s language, more attention should be paid to language use in social context. What＇s more, the linguistic phenomena in a speaking community can be understood more thoroughly.     

低渗透非均质砂岩油藏启动压力梯度研究

理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。     

On Tragic Consciousness In The Works By Ernest Hemingway

As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.     

Achieving Unusual States of Matter Under High Pressure

正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-     

Exchange-Correlation and Electronic Excitation Energies from Pairing Matrix Fluctuations

We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-     

Density Functional Theory for the Response of Periodic Systems to Electric Fields Based on the Vector Potential Approach

正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that     

On the Thermodynamic Limit for Responses to Static Electromagnetic Fields

For molecular systems,the quantum-mechanical treatment of their responses to static electromagnetic fields usually employs a scalar-potential treatment of the electric field and a vector-potential treatment of the magnetic field.Although the potential for each field separately is associated with the choice of an(unphysical)origin,the precise choice of the origin for the electrostatic field has little consequences for the results.This is different for the     

Call for Papers

<正>"The Journal of Shanghai Normal University:Mathematics"is published by Shanghai Normal University as regular issues of The Journal of Shanghai Normal University each year from 2014 in English.The editors-in-chief of the issues are professors Yuhao Cong and Maoan Han.The Journal of Shanghai Normal University was started in 1958 with     

Journal of Donghua University ( English Edition) Contents of Volume 31

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