定向凝固合金DZ466在涂 NaCl/Na2 SO4盐条件下热腐蚀行为

采用涂NaCl/Na2 SO4盐方法研究了DZ466合金在850℃和950℃条件下热腐蚀行为.结果表明：合金的腐蚀层包括三个区域,最外层为( Ni,Co) O氧化物层,次外层为尖晶石结构氧化层( Ni,Co) Cr2 O4,内层为内腐蚀层,850℃时该层为Ni3 S2,而950℃时除Ni3 S2外,在靠近次外层还形成内氧化Al2 O3;在850℃和950℃时合金的热腐蚀机制相同,氧化膜连续性的破坏,是合金遭受热腐蚀的主要原因;热腐蚀增重曲线均符合抛物线规律,其速率常数分别为3.1×10-11 g2·cm-4·s-1和1.5×10-9 g2·cm-4·s-1,热腐蚀激活能分别为179.2 kJ·mol-1和138.3 kJ·mol-1.     

SiC_p/2024Al铝基复合材料及其阳极氧化膜的腐蚀行为

用电化学方法研究了碳化硅颗粒增强2024铝(SiCp/2024Al)基复合材料及其硫酸阳极氧化膜在35%NaCl水溶液中的耐蚀性;作为比较,对2024Al的耐蚀性也进行了研究·结果表明,SiCp/2024Al复合材料在35%NaCl水溶液中比相应的基体金属有较大的腐蚀敏感性·SiCp/2024Al复合材料的阳极氧化膜具有良好的耐NaCl溶液腐蚀的能力,但其耐蚀性不如2024Al合金的阳极氧化膜,这是由于氧化膜中SiC颗粒的存在破坏了氧化膜的完整性和均匀性所致·     

原位反应TiCP/3 Crl 3复合材料的抗氧化性能研究

研究了原位反应法制备的TiCp/3Crl3钢基复合材料在850℃和950℃的抗 氧化性能．结果表明：与基体合金相比,在850℃条件下,由于TiC颗粒的引入,复合 材料在氧化初期具有短路扩散效应,稳定阶段它的氧化动力学曲线符合对数增长规 律,氧化膜由棱角多面体状的Cr2O3组成,复合材料具有理想的氧化膜结构和优良的 抗氧化性能;在950℃条件下,氧化膜由粗大的FeO·Cr2O3组成,氧化膜致密度下降, 复合材料的抗氧化性能提高不多．,The oxidation resistance of TiC paniculate reinforced 3Cr13 matrix composites prepared by in-situ process at a temperature of 850 ℃ and 950 ℃ has been investigated, the results showed that, com pared to 3Cr13 matrix, the short path diffussional effect is caused by TiC phase at initial oxiding stage, the cruves for oxiding kinetics of comoposite agrees with the law of logarithmic growth. The oxide film consists of polyhedron-like Cr2O3, the composite has an ideal structure of oxide film and excellent oxida tion resistance at 850 ℃. The oxidation resistance of composite increases a little at 950 ℃ due to the de crease in compactivity of oxide film and the increase in size of (FeO· Cr2O3) oxide.     

用柠檬酸溶胶凝胶法合成SrFeCo_(0.5)O_x氧化物

采用柠檬酸溶胶凝胶法合成SrFeCo0 5Ox混合导体氧化物·利用XRD、TEM以及DTA方法研究与分析了不同条件下样品的晶体结构组成、相貌·确定了最佳制备条件·结果说明在燃料剂/氧化剂比例为0 64,550℃时得到单相钙钛矿氧化物,氧化物为纳米球形颗粒,尺寸分布均匀;加热温度升高850℃晶体结构无变化,颗粒尺寸明显长大但是形状不变·同时分析了溶胶凝胶反应过程及影响因素·     

煤燃烧过程中吡啶型氮迁徙规律的实验研究

为了解煤燃烧过程中NOx的生成机理,选用纯净杂环化合物吡啶作为煤中氮元素有机形态的模型化合物,对其热解及氧化规律进行实验研究.红外光谱仪分析结果表明:吡啶杂环在750℃时开始裂解;在850℃时腈类物质生成量最大;高温下含氮产物几乎全部以HCN的形式存在;N2O主要由腈类物质转化而成;从氧气的摩尔比等于6 0开始,随着氧气量的增加,N2O的生成量急剧增加.在缺氧状态下,高浓度CO造成的还原气氛使NOx生成受到很大程度的抑制.当温度高于850℃时,N2O向NO、NO2转化,当温度大于1000℃时,N2O全部转变为NO、NO2.NO、NO2主要由HCN裂解转化而成.     

Cu-Ni-Al惰性金属阳极铝电解应用测试

采用Cu Ni Al合金作金属阳极 ,在温度 75 0～ 85 0℃ ,电流密度 0 75～ 1 1 0A/cm2 的不同分子比和氧化铝质量分数的Na3 AlF6 NaCl CaF2 Al2 O3 熔盐中进行电解测试·结果表明 ,在不同电解操作条件下该阳极材料的腐蚀程度不一样 ,阳极在熔盐中的腐蚀速率远大于在空气中的氧化腐蚀速率 ,而且阳极电解的腐蚀速率与电解质中的氧化铝质量分数相关 ,氧化铝质量分数大 ,则阳极腐蚀速率小·另外 ,与碳阳极相似的是在高电流密度下腐蚀速率反而小·该材料是一种可开发的惰性阳极材料     

赛隆-碳化硅系复合材料的合成及其应用

以蜡石和碳黑为原料,通过碳热还原法合成了赛隆-碳化硅系复合材料,将其作为添加剂应用于Al2O3 C系不定形耐火材料中·考察了加热温度对赛隆-碳化硅系复合材料合成过程的影响以及添加赛隆-碳化硅系复合材料对耐火材料性能的影响·研究结果表明,通过向蜡石中添加适量的碳黑,并将蜡石和碳黑的混合物在氮气气氛下加热到1540℃时,可以很容易地合成赛隆-碳化硅系复合材料·通过添加适量的赛隆 碳化硅系复合材料,Al2O3 C系不定形耐火材料的抗氧化性能、抗渣侵蚀性能以及高温抗折强度均得到了明显的改善·     

HR3C抗高温硫酸盐腐蚀行为研究

利用X射线衍射、扫描电镜以及电子探针等方法开展了HR3C在750℃下抗碱金属硫酸盐高温腐蚀行为与机理的研究.结果表明:HR3C在750℃、Na2SO4和K2SO4存在条件下的腐蚀动力学曲线可分为两段.前期腐蚀以高温氧化为主,由于生成Cr2O3氧化膜,腐蚀动力学曲线呈现上升趋势;随着腐蚀时间的延长,由于碱金属硫酸盐对氧化膜的破坏程度逐渐加重,以及腐蚀产物Na4(CrO4)(SO4)的大量挥发,动力学曲线呈现下降趋势,硫酸盐通过疏松的氧化膜与基体接触导致基体出现了裂纹及孔洞等缺陷并且产生了严重的内硫化现象.     

原位合成莫来石碳化硅系复合材料

以铝硅系天然矿物蜡石和天然石墨为原料,通过碳热还原法原位合成了莫来石碳化硅系复合材料·并对合成复合材料的韧性、抗压强度和抗渣侵蚀性能进行了测定·研究结果表明,通过向蜡石中添加适量的天然石墨,并将蜡石和天然石墨的混合物在氩气气氛下加热到1550℃以上时,可以很容易地合成莫来石碳化硅系复合材料;原位还原合成的碳化硅多呈球状,颗粒粒径在1μm左右且均匀地分布在生成的莫来石相中;与单一的莫来石材料相比较,合成的莫来石-碳化硅系复合材料的韧性、抗压强度和抗渣侵蚀性能明显提高·     

310SS在KCl盐膜下高温空气中腐蚀机理

研究了310SS在表面覆有KCl盐膜时于750-800℃下的腐蚀，结果表明，750℃时在固态氯化物盐膜下，310SS加速腐蚀主要按“活化氧化”机理进行，而在熔融态盐膜下尚受到800℃熔盐的影响，另外，经长期时效处理后，310SS除均匀腐蚀外，沿晶界σ还发生了择优腐蚀，从热力学和动力学两方面讨论了材料的加速腐蚀机理。     

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.     

An Analysis of Catherine＇s Character——Wuthering Heights

Wuthering Heights, Emily Bronte＇s only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.     

Lower Paleozoic oil relationships within Williston Basin, Canada

The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.     

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     

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