采用热压工艺制备高纯致密Ti3SiC2材料

原料摩尔配比为n(TiC)∶n(Ti)∶n(Si)∶n(Al) =2∶1∶1∶0 .2的起始混合粉料在 130 0～ 14 0 0℃和 30MPa压力下热压 2h制得高纯致密Ti3 SiC2 块体材料 .添加适量铝作助剂显著加快Ti3 SiC2 的反应合成 ,并使Ti3 SiC2 在 12 0 0℃下大量生成 ,能谱仪分析表明Al在材料中均匀分布 .所得Ti3 SiC2 颗粒为板状结晶形貌 ,平面内尺寸大小为 3～ 8μm .     

Ti3SiC2的高速摩擦特性及摩擦氧化行为

研究了高纯度多晶块体Ti3SiC2高速摩擦特性及摩擦氧化行为．实验在盘-块式高速摩擦试验机上进行，以低碳钢为对磨体，温度25℃，相对湿度23％～25％，滑动速度20～50m／s，法向压强0.1～0．8MPa．结果表明，摩擦系数随滑动速度的提高而减小，而在给定的滑动速度下随法向压强的增大先增大后减小，在40～50m／s的滑动速度和0．8MPa的法向压强下达到最小值0．17．摩擦系数的减小归因为Ti3SiC2表面摩擦氧化层的存在．该氧化层由Ti、Si和Fe的氧化物组成，具有显著的减摩作用．     

紫外光固化光敏稀释剂的合成及性能研究

先将新戊二醇二缩水甘油醚（NGE）与二元酸反应，再与丙烯酸单体作用，合成了一种新型光敏活性稀释剂，研究了反应温度，原料配比，阻聚剂、催化剂用量等因素对反应的影响．采用的合成条件为：反应温度90-100℃，缩水甘油醚与二元酸的摩尔比为2：1，N，N-二甲基苯胺的质量分数为1．0％，对苯二酚的质量分数为0．50％．将所合成的光敏稀释剂配合光引发荆、光敏树脂（EA）和适量涂料助剂制成光固化涂料，对其紫外光固化涂料进行拉伸实验，得到漆膜的拉伸强度为12．97MPa、弹性模量为92．44MPa、断裂伸长率为17．58％．制成的光固化涂料具有良好的贮存稳定性、高的邵氏A硬度值（〉95．0）和小的固化体积收缩率（约7．4％）．     

含Nb,Ti冷轧薄板工艺研究

研究了工艺参数对含（0．062-0．075)Nb,(0．025-0．028)Ti冷轧薄板性能的影响。结果表明,冷轧压下率每增加10％,抗拉强度提高45MPa。经(600-650)℃,2h退火,可完成再结晶,消除加工硬化,钢的性能恢复到热轧钢坯的水平．平整压下率为0．7％～1％时,平整使屈服强度下降40MPa。     

高纯Ti3SiC2块体的热压原位合成及性能研究

以Ti、Si和石墨粉为原料,以少量的Al为反应助剂,用反应热压(HP)工艺在1 450 ℃和25MPa下2 h制得纯度为97%、相对密度为98.45%、粒度为5～10 μm的Ti3SiC2多晶块体.其弯曲强度为407 MPa、室温电阻率为0.22×10-6 Ω·m、维氏硬度为3.97 GPa.与Barsoum和Ei-Raghy在1 600 ℃和40 MPa下烧结4 h获得的样品相比,本样品显示了较低的弯曲强度,基本相同的纯度、电阻率和硬度.     

镍负载硅酸铝催化剂上丙烯齐聚反应(Ⅱ)

采用真空静态循环装置和ＸＲＤ,ＥＳＲ技术研究了镍负载硅酸铝催化剂上的丙烯齐聚反应．系统地考察了催化剂制备条件和反应条件对低压下丙烯齐聚反应催化性能的影响．结果证明,最佳条件为Ｎｉ含量７％～８％,活化温度５５０～６００℃,预抽空处理温度４００℃以上,反应温度１３０～１５０℃．同时发现镍含量在７％～８％时,催化剂表面有新晶相形成,预抽空过程是一还原过程．     

镍负载 AlMCM-41催化剂上正辛烷的加氢异构化研究

为研究镍负载AlMCM-41催化剂的催化性能,合成了一系列不同硅铝比的AlMCM-41中孔分子筛,担载活性非贵金属组分镍（ Ni）,制得烷烃异构化催化剂Ni-AlMCM-41。以正辛烷为模型化合物,在连续流动固定床反应器上评价了催化剂对正构烷烃异构化反应的催化性能,考察了催化剂不同的还原温度、反应温度、Si/Al、Ni负载量等因素对辛烷临氢异构化反应的影响。研究表明：在还原温度430℃,反应温度300℃,Si/Al为20％～30％,Ni负载量为3％～4％的条件下,其异构化选择性达到44．8％～42．0％,正辛烷的转化率达到58％～75％。     

Ti（SO4）2／C催化合成邻苯二甲酸二异戊酯（DIAP）

研究了Ti(SO4)2/C在邻苯二甲酸和异戊醇酯化中的催经性能，结果表明，Ti（SO4)2/C该反应中具有较高的催化活性，并得到了合成邻苯二甲酸二异戊酯的新工艺条件是：催化剂用量（邻苯二甲酸酐质量分数）为5％；异戊醇0．5mol，邻苯二甲酸酐0．2mol，反应温度185℃，反应时间180min，在此条件下收率可达95％。     

无镍不锈钢17Cr10Mn2MoN的制备与性能

采用气雾化法制备含氮无镍不锈钢粉末，利用热等静压成形并对材料进行固溶处理．热等静压后，材料具有良好的强度、塑性及韧性，抗拉强度为850MPa，屈服强度为505MPa，延伸率为44．5％，断面收缩率为47．5％，冲击功为44J．材料经1100℃固溶处理1h后，塑性和韧性得到进一步提高，延伸率为50．0％，断面收缩率为55．5％，冲击为68J．材料强度和耐蚀性优于316L不锈钢．     

香桂叶油合成二氢黄樟油素

以香桂叶油为原料合成二氢黄樟油素为目的，在W-2型瑞尼镍的催化下加氢，并研究了催化剂用量、温度、压力和溶剂对反应的影响。结果表明：香桂叶油在无溶剂条件下。用32：1的W-2型瑞尼镍催化，在120℃、2MPa的氢气压力下反应2h，可合成二氢黄樟油素，不经过蒸馏提纯，质量分数为98．5％，产率为95．6％，无废水和废渣排放。     

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.     

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     

An affordable accurate evaluation of the binding conformations predicted by molecular docking studies in bio-system

Franck-Condon factors bridge the gap between theoretical modeling and experimental observations for molecular electronic spectroscopy and electron transfer.Under the displaced harmonic oscillator approximation,multidimensional Franck-Condon factors are decomposed into a product of many one-dimensional(1D)Franck-Condon(FC)factors,and each 1D-FC factor is associated with one Huang-Rhys factor that determines the leading contribution of     

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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