硬脂酸对三水碳酸镁晶须表面改性的研究

采用硬脂酸对三水碳酸镁晶须进行了表面改性,考察了改性剂用量、料浆浓度、改性时间等因素对三水碳酸镁晶须表面改性的影响.采用接触角、活化指数、扫描电子显微镜、热重分析和红外光谱分析对改性前后的三水碳酸镁晶须进行表征.结果表明,最佳改性条件为改性剂用量5%,料浆质量分数5%,改性时间60min.在最佳工艺条件下,改性产品的接触角为130°,活化指数为1.000.表面改性过程对三水碳酸镁晶须的热分解没有明显影响.硬脂酸与三水碳酸镁晶须的结合方式主要是镁离子与羧基形成憎水性的硬脂酸镁保护层.     

辉光放电空气等离子体改性聚砜膜的研究

为了研究空气中等离子体改性对聚砜(PSF)超滤膜性能的影响,通过辉光放电空气等离子体对聚砜膜进行表面改性,采用亲水接触角法评价了改性条件对聚砜膜表面性质的影响规律.采用牛血清蛋白溶液作为类蛋白污染物进行试验,评价了改性前后聚砜膜的渗透性、污染率、恢复率等性能.结果表明,聚砜膜表面经等离子体处理后,表面润湿性发生变化,在最佳表面改性条件(放电功率8W,放电时间30s)下,膜表面的水接触角从69°下降到20°.改性后的聚砜膜渗透性能提高,抗污染性能得到了明显改善.     

普通硅酸盐表面的疏水改性及微纳结构表征

通过十八烷基三氯硅烷(OTS)硅烷化自组装方法,实现了普通硅酸盐玻璃的表面疏水改性,改性后的玻璃表面具有疏水性和良好的透光性.该方法首先运用氢氟酸(HF)溶液预处理玻璃表面,进行化学织构化,形成微纳结构,然后利用OTS分子在玻璃表面自组装形成疏水分子膜.实验考察了HF溶液的处理时间、OTS甲苯溶液的浓度及其处理时间、以及其他预处理方法对玻璃表面接触角的影响,得到了一种简便易行的玻璃疏水改性处理方法,能够方便的制备出接触角为107o的透明疏水玻璃.同时,运用原子力显微镜(AFM)测定了光面玻璃和磨砂面玻璃在疏水改性过程中玻璃表面微观结构的变化,提出了该疏水改性方法的作用机理.     

普通硅酸盐玻璃表面的疏水改性及其微纳结构表征

通过十八烷基三氯硅烷(OTS)硅烷化自组装方法,实现了普通硅酸盐玻璃的表面疏水改性,改性后的玻璃表面具有疏水性和良好的透光性.该方法首先运用氢氟酸(HF)溶液预处理玻璃表面,进行化学织构化,形成微纳结构,然后利用OTS分子在玻璃表面自组装形成疏水分子膜.实验考察了HF溶液的处理时间、OTS甲苯溶液的浓度及其处理时间、以及其他预处理方法对玻璃表面接触角的影响,得到了一种简便易行的玻璃疏水改性处理方法,能够方便的制备出接触角为107o的透明疏水玻璃.同时,运用原子力显微镜(AFM)测定了光面玻璃和磨砂面玻璃在疏水改性过程中玻璃表面微观结构的变化,提出了该疏水改性方法的作用机理.     

硬脂酸改性处理TC4钛合金微弧氧化膜层耐蚀性的研究

在Ti₆Al₄V合金微弧氧化膜层上采用硬脂酸改性处理实现了陶瓷膜层的疏水化转变，显著提高了钛合金的耐蚀性能。利用接触角测试仪、扫描电子显微镜（SEM）、能谱仪（EDS）和傅里叶变换红外光谱仪（FT-IR）对膜层的润湿性、稳定性、微观结构和化学组成进行了分析，并通过动电位极化曲线和电化学阻抗分析了其腐蚀行为。结果表明，改性处理得到的疏水微弧氧化膜层试样能有效修复微弧氧化膜层缺陷，提高钛合金的耐蚀性能，说明硬脂酸改性处理与微弧氧化技术相结合有助于拓宽微弧氧化技术在钛合金上的应用。     

阳极氧化Ti-6Al-4V合金表面TiO2多孔膜的制备及研究

在一定浓度的H₂SO₄溶液中对Ti-6Al-4V合金表面进行阳极氧化处理,通过改变阳极氧化处理的电压、氧化时间和电解液浓度,研究了预处理工艺参数对钛合金表面形貌、物相、润湿性及粗糙度的影响.试验结果表明：钛合金经过阳极氧化处理后,表面出现了二氧化钛（TiO₂）纳米多孔结构,多孔氧化膜由锐钛矿型和金红石型TiO₂组成;在0.5 mol·L^-1 H₂SO₄溶液中,随着阳极氧化电压的增加,多孔膜的孔径逐渐增大,基体表面与模拟体液（SBF）的接触角明显降低,经120 V氧化处理的试样表面接触角由预处理前的52.8°降至16.9°左右,具有良好的润湿性;并且试样表面的粗糙度明显增加,在电压为120 V时粗糙度达到0.56 μm.在电压120 V时,随着阳极氧化时间或电解液浓度的增加,TiO₂多孔膜的含量和孔径尺寸逐渐增大,试样表面的润湿性和粗糙度也不断增加,在氧化时间10 min或电解液浓度0.5 mol·L^-1时达到最大,氧化时间大于10 min或电解液浓度高于0.5 mol·L^-1时,试样表面出现裂纹,多孔结构被破坏.     

阴极极化法制备AZ91D表面铈转化膜的研究

应用阴极极化技术在AZ91D镁合金表面形成铈盐转化膜,研究了转化膜的腐蚀防护作用.腐蚀行为的测试是将阴极极化成膜试样、浸泡转化成膜试样和基体在3.5%NaCl溶液中进行动电位极化测试,结果表明:阴极极化铈盐转化成膜处理可使合金的腐蚀电位正移,出现钝化现象,自腐蚀电流密度明显降低,阴极转化成膜可以对AZ91D镁合金起到理想的防护作用.     

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.     

铝合金表面构建超疏水性的化学改性机理

系统研究了刻蚀一化学改性两步法中的蒸镀改性工艺对铝合金表面形貌和润湿性的影响,提出了刻蚀与化学改性同时进行的一步浸泡法制备超疏水铝合金.结果表明,两步法蒸镀改性工艺中,硬脂酸端部的极性亲水羧基与铝合金表面羟基以共价键结合,从而在铝合金表面形成一层硬脂酸膜,使铝合金实现低表面能化,水滴在其表面处于Cassie状态,接触角...     

纯镁表面聚多巴胺膜的制备及表征

为降低纯镁的腐蚀速率和赋予镁材料较好的细胞亲和力,通过溶液浸泡法在纯镁表面成功制备了单一聚多巴胺(PDA)膜和Mg(OH)2-PDA复合膜,通过单因素实验确定两种膜层制备的最佳工艺,利用场发射扫描电镜和动电位极化法分析了DA质量浓度与成膜时间对膜层形貌和耐蚀性的影响,利用傅立叶反射红外分析研究了两种膜层的化学结构.结果表明:制备PDA膜的最佳工艺条件为DA质量浓度1. 0 g/L、成膜时间12 h,制备Mg(OH)2-PDA复合膜的最佳工艺条件为DA质量浓度1. 5 g/L、成膜时间20 h;最佳工艺参数下基体的耐蚀性能得到显著提高,Mg(OH)2-PDA复合膜的耐蚀性最好;在纯镁上获得的PDA薄膜有明显裂纹缺陷;水热处理得到的Mg(OH)2膜层的微观结构为与聚多巴胺结合提供了更好位点,得到了更均匀的聚多巴胺膜.     

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

正~~