采用金属阳极溶解法合成纳米MgO前驱体

以金属镁作为“牺牲”阳极,在乙酰丙酮醇溶液中,采用电化学溶解金属镁一步制备了纳米MgO前驱体Mg(OEt)2-x(acac)x,Mg(OBu)2-x(acac)x[acac为乙酰丙酮基]．通过傅里叶变换红外光谱(FT-IR)、拉曼光谱(Raman spectrum)对其进行了表征．可讨论了影响电合成镁醇盐配合物的关键因素．实验表明,温度控制在40～50℃,导电盐Bu4NBr浓度为0．04～0．05mol／L较为适合,同时防止阳极钝化,有利于提高电合成效率。     

“阳极溶解法”制备金属醇盐及其影响因素

采用金属为“牺牲”阳极,在无隔膜电解槽中,一步法制备金属醇盐：Ti(OEt)4、Ti(OPr-i)4、Ti(OMe）4（acac）、Cu(OEt)2、Cu(OBu)2、Ni(OEt）2和Mg(OEt）,产物通过元素分析、红外光谱进行表征,实验表明电极表面粗糙化处理,防止阳极纯化,温度控制在50－60℃之间,采用有机溴化胺电导盐,可以提高电合成收率,采用合金电极,可以有效克服不溶性金属醇盐在阳极的吸附问题,并同时合成几种金属醇盐,从而提高反应的电流效率。     

基于片状前驱体组装中孔NiO微球

利用醇水混合溶剂作为反应介质,以硝酸镍(Ni(NO3)2·6H2O)为Ni源,尿素(CO(NH2)2)为沉淀剂,合成一种纳米片组装的碱式镍化合物微球,经热处理得到由NiO中孔纳米片组装的微球.采用X射线衍射仪、环境扫描电镜、傅立叶红外光谱仪和比表面及孔径分布测试仪对产物进行表征.结果表明:所得前驱体是一种片状结构的碱式碳酸镍盐(NiO2.45C0.74N0.25H2.90),经热处理后NiO纳米片单元上形成2.5和40 nm 2种孔径的中孔结构.改变尿素用量由0.01 mol增加至0.03 mol,会形成Ni(HCO3)2颗粒,从而改变微球表面形貌.结合PEG的模板作用和层状碱式金属盐类物质的成核及生长特性,提出了微米尺度球形组装NiO中孔纳米片的可能生长机理.     

电解法制备纳米NiAl2O4粉体

讨论了温度、(Bu4N)Br浓度对电合成镍、铝醇盐配合物的影响,以金属阳极溶解法在乙醇和乙酰丙酮混合溶液中(按Ni与Al电量比为1∶3)依次电解铝片、镍片,制得复合氧化物纳米粉体NiO-Al2O3的前驱体NiAl2(OCH2CH3)(8-y)(acac)y[acac为乙酰丙酮基].将含有前驱体的电解液控制pH=8.5直接水解形成凝胶,凝胶经洗涤,干燥后在350°C煅烧2h,制得纳米NiAl2O4粉体.采用红外、差热-热重分析、X-射线衍射、电子透射技术等手段对前驱体和纳米NiAl2O4进行了表征.实验表明温度控制在54～60°C,导电盐Bu4NBr浓度为0.040～0.045mol/L较为适合;电解法可以在350°C下制备得到纳米NiAl2O4粉体,平均粒径在20～30nm.     

氢氧化镍纳米晶的制备与表面有机化

以乙醇为反应介质,浓氨水为沉淀剂,醋酸镍为镍源,在水热条件下制备了具有片状结构的β-Ni(OH)2纳米晶;然后采用种子乳液聚合的方法实现了β - Ni(OH)2纳米晶的表面有机化.通过XRD,TEM,UV - vis,FT-IR以及分散性实验对β - Ni(OH)2的结构及表面有机化进行了表征.结果表明,采用种子乳液聚合方法成功实现了片状β - Ni(OH)2纳米晶的表面有机化.     

均匀沉淀法制备纳米氧化镍的研究

文中采用Ni(NO3)2·6H2O为主要原料,CO(NH2)2为沉淀剂制备了球片状纳米NiO粒子,并研究了反应物料配比、反应温度以及煅烧温度等条件对产品粒径和产率的影响.采用热重-差热(TG-DTA)、透射电子显微镜(TEM)、电子衍射(ED)、X射线衍射(XRD)等分析手段对产物性能进行了表征.结果表明中间产物从320℃开始分解;粒子形貌基本呈球状,平均粒径15 nm左右,分散性良好;制得的纳米NiO粒子结晶性完好,属纯度较高的立方晶系结构,晶型完整.     

三乙烯四胺/蒙脱土纳米复合材料的制备与表征

将蒙脱土的硅酸盐晶层空间作为形成配合物的微反应场所,利用微波加热和水溶液加热的方法将钠基蒙脱土转化为镍基蒙脱土,再在不同的溶剂配比条件下引入三乙烯四胺配体,使三乙烯四胺与镍离子在蒙脱土层间原位反应生成配合物,制得蒙脱土纳米复合体.XRD结果表明蒙脱土的层间距在引入三乙烯四胺后明显变大.红外光谱分析结果表明,三乙烯四胺与Ni2 离子在蒙脱土层间形成了配合物,且层间配合物的立体结构与溶液中制备的[Ni2trien3]Cl4的结构不同.     

PVA/NiO复合纳米纤维的制备及光催化性能

采用静电纺丝法,以聚乙烯醇(PVA)和硝酸镍(Ni(NO3)2)为前驱物,制得PVA/Ni(NO3)2纤维;再以尿素(CO(NH)2)为碱源,通过水热合成法制备了PVA/NiO复合纳米纤维.利用X射线衍射(XRD)、红外光谱(FT-IR)、扫描电镜(SEM)和透射电子显微镜(TEM)等分析测试手段对样品的形貌和结构进行了表征,以罗丹明B为目标降解物,考察了PVA/NiO复合纳米纤维的光催化活性.结果表明:NiO纳米粒子均匀地负载于PVA纳米纤维上,形成了具有良好光催化活性的PVA/NiO复合纳米纤维光催化材料.     

镍超氧化物歧化酶模型化合物的合成、表征和量化计算

以N,N,N',N'-四(2-苯并咪唑亚甲基)-1,2-乙二胺(EDTB)为配体,合成了一种新的Ni( )单核配合物即镍超氧化物歧化酶(Ni-SOD)的模型化合物.采用元素分析、UV和IR光谱对其进行了结构表征,应用X射线衍射方法测定了其晶体结构,并利用G98W程序在HF/LanL2DZ基组水平上对该单核配合物进行了量子化学计算.晶体结构分析表明,Ni( )单核配合物的化学式量分子(C38H46Cl2N10NiO11S)的单胞中含有2个配合物分子{Ni[C34H32N10]·(ClO4)2·2(CH3OH)·(CH3)2SO},Ni( )与配位原子形成六配位的扭曲八面体结构.量化计算所得原子轨道贡献和原子净电荷布居分析结果与晶体结构中的配位情况相符.     

电沉积纳米晶体电催化电极的制备及性能

利用恒电流电沉积的方法从含有糖精,温度为50～60 ℃,pH＜3的瓦特槽中用直流和脉冲的方式制备纳米晶体镍、镍-钴合金电催化析氢电极.X衍射、扫描电镜(SEM)和能谱(EDS)分析结果表明此类金属(Ni)或合金(Ni-Co)表现出很强的(111)织构;该晶体为纳米晶体,其中含有少量硫;由电沉积纳米晶体制备成的电极在1 mol*L-1硫酸中比常规的金属Ni或电沉积粗晶镍有较强的电催化活性、稳定性和耐蚀性.     

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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