Ni-Cr-Mo-Cu合金的高温氧化特性

运用静态等温氧化法研究了自制Ni-Cr-Mo-Cu耐蚀合金在600、800、1 000℃下的氧化特性,采用X射线衍射对氧化层进行了相的分析,并用电子显微镜对氧化层形貌进行观察.结果表明,Ni-Cr-Mo-Cu耐蚀合金氧化时先发生选择性氧化生成Cr2O3,随后发生分层氧化生成NiO和NiCr2O4,在高温长时间下Ni-Cr-Mo-Cu耐蚀合金表现出较不锈钢更为优越的抗氧化性能.     

Ti-15Mo-3Al-2.7Nb-0.3Si合金微弧氧化处理工艺研究

通过研究微弧氧化的工艺条件,制备具有生物活性的陶瓷膜,得到适宜于制备多孔生物活性膜的电解液配方,其中(CH3COO)2Ca?H2O的浓度为0.1mol/L、NaH2PO4?2H2O的浓度为0.06~0.2 mol/L,脉冲电压为400V~500V。结果表明,随电解液浓度的增加,起弧电压降低,陶瓷层孔隙率最大达到17.58%,脉冲电压在400V~500V之间时,表面涂层中锐钛矿相TiO2最大,且无微裂纹产生。采用该微弧氧化工艺,合金表面制备的陶瓷膜具有分布均匀的多孔结构。     

确定氧化数的新方法

确定氧化数的新方法是利用分子的Lewis结构和元素电负性表,画出键合电子的归属图,从自由原子的价电子数减去围绕分离原子的价电子数的差等于该原子的氧化数。     

氧化锌矿的基本物性及高温氧化焙烧实验

通过对氧化锌矿的矿物组成、熔化温度等基本物性的研究，确定采用高温氧化焙烧的方法对氧化锌矿进行焙烧实验；试验结果表明；在所有的焙烧实验条件下，烧损率的变化并不明显，在30％左右；提高温度，可提高焙烧效果，焙烧的适宜温度为1200℃；增加焙烧时间，其焙烧效果与矿石焙度有关，粒度为5－10mm，焙烧时间为90min的焙烧效果较好，而粒度为15－20mm时，120min的效果较好；增加粒度有利于提高焙烧效果，矿石的适宜粒度为15－20mm。     

CaO(C),La_2O_3/CaO(LC)和SrO-La_2O_3/CaO(SLC)催化剂上的甲烷氧化偶联V:催化剂对产物C_2烃氧化的抑制作用

Ｃ，ＬＣ和ＳＬＣ催化剂上的甲烷氧化偶联及其相应的Ｃ２产物的催化氧化和它们的气相反应的研究结果表明：这些催化剂明显地抑制Ｃ２Ｈ４的氧化反应，其抑制能力由小到大按Ｃ，ＬＣ，ＳＬＣ顺序增加．而在甲烷氧化偶联反应中，Ｃ２产率和选择性同样按此顺序增加．这表明在甲烷氧化偶联反应中，催化剂Ｃ，ＬＣ，ＳＬＣ起着抑制Ｃ２Ｈ４产物深度氧化的作用．这一顺序也同ＣＯ２ＴＰＤ表征的催化剂碱强度顺序一致．关联结果说明：这种抑制效应可能与催化剂的内在碱性有关．研究同时表明：在优化组成的ＳＬＣ催化剂上的甲烷氧化偶联反应中，Ｌａ２Ｏ３可能有利于·ＣＨ３自由基的产生；ＣａＯ有利于产物Ｃ２Ｈ６的氧化脱氢生成Ｃ２Ｈ４；而ＳｒＯ的引入则对最终产物Ｃ２Ｈ４的深度氧化起着抑制作用．     

实验分析12CrMoV高温合金在外拉伸力作用下的高温氧化规律

在大量实验的基础上,对12CrMoV合金钢在外加拉伸力时的高温氧化过程进行试验研究。比较分析了在相同温度条件下有外加拉伸力和没有外加拉伸力时的12CrMoV合金钢的高温氧化反应速率、高温氧化导致的裂纹、氧化层脱落,从而发现了外加拉伸作用力对12CrMoV合金钢高温氧化过程的影响规律。     

化学氧化技术处理水体中抗生素的研究进展

由于抗生素的大量生产和过度使用,近年来在全球水体和土壤中被频繁检测到,这不仅对生态系统造成了危害,同时威胁着人类的健康.化学氧化技术可将抗生素分解成无毒或毒性较低的小分子物质,从而降低抗菌活性,并提高其可生化性和矿化率.针对水中抗生素的化学氧化处理,着重综述臭氧直接氧化及臭氧高级氧化、氯氧化、芬顿及类芬顿法这3类化学氧...     

化学反应规律探讨(Ⅰ)——氧化还原反应

化学反应的很大一部分是氧化还原反应,本文总结了一些判断氧化还原反应产物的规律。以帮助学生对化学反应方程式的理解与记忆,并激发其学习无机化学的兴趣。     

Inconel718合金高温氧化行为

为探究电渣重熔冶炼Inconel718合金过程中电极氧化机理,研究了Inconel718合金在1 150℃下的高温氧化行为。结果表明,在1 150℃下,Inconel718合金氧化动力学曲线遵循线性关系。在高温氧化期间,Cr和Ni等合金元素会快速氧化形成富Ni和Fe及Cr的Cr_2O_3、Fe_2O_3、3Cr_2O_3·Fe_2O_3和含Ni的尖晶石Cr_2O_3·NiO。随着氧化时间的增加,Ti元素发生氧化形成TiO_2,Ti元素向外扩散的同时在氧化层间形成孔隙,加速氧元素向基体内部扩散,进而加速了其他合金元素的氧化。     

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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