低碳钢A-TIG焊接法的试验研究

研究了一种高效的 TIG焊接方法 A- TIG,进行了系列 TIG焊堆焊试验 .结果表明 :在相同焊接规范下 ,涂敷表面活性剂后焊接电弧有明显收缩 ,熔池深度有显著增加 ,而熔宽稍有减小 .同时还介绍了活性剂成分的调配及活性剂成分对熔深变化的影响 ,并对熔深增加机理进行了分析     

低碳钢A-TIG焊活性剂的焊接性研究

利用自行研制的低碳钢A TIG焊活性剂进行了各种焊接工艺试验 .试验结果表明 ,使用本活性剂可使焊缝熔深比常规的TIG焊增加 3倍 ,对 12mm以下的低碳钢板对接无须开坡口 ,可一次焊接完成并能单面焊双面成型 .焊缝表面成型良好 ,接头微观组织、焊缝的化学成分和接头力学性能均不受影响 .焊接电流、弧长、焊接速度、涂层厚度和气体种类等均对焊接熔深的增加产生影响     

耦合电弧对AA-TIG焊接熔深的影响

为提高活性TIG焊活性剂的涂敷效率,实验一种新型的活性TIG焊工艺电弧辅助活性TIG焊,简称AA-TIG焊.以SUS304不锈钢作为母材,采用耦合电弧进行AA-TIG焊,研究焊接电流、焊接速度、钨极夹角、CO2气体含量等主要工艺参数对焊缝熔深、熔宽的影响.结果表明:相同的焊接工艺参数下,耦合电弧AA-TIG焊缝熔深达到传统TIG焊熔深的2.86倍,同时焊缝熔宽明显收缩.采用耦合电弧AA-TIG焊可不开坡口一次焊透8 mm厚不锈钢板,焊接效率明显提高.辅助电弧和正常TIG焊工艺参数都对耦合电弧AA-TIG焊焊缝熔深、熔宽有一定影响,其中辅助电弧CO2含量以及2电弧钨极夹角对焊缝成形影响较大.     

不锈钢A-TIG焊活性剂的焊接性研究

利用自行研制的 30 4不锈钢A TIG焊活性剂进行了焊缝外观形貌、熔深效果、接头微观组织、化学成分及接头力学性能分析的焊接工艺试验 .试验结果表明 ,使用活性剂可以使焊缝熔深比常规的TIG焊增加 1～ 2倍 ,对 8mm以下的不锈钢钢板对接无须开坡口 ,可一次焊接完成并且单面焊双面成型 ,焊缝表面成形良好 .使用活性剂后接头微观组织、焊缝的化学成分和接头力学性能均不受影响 .     

适用于不同金属材料的气体输送活性焊接方法

为实现不同种类金属材料的自动化焊接,通过改变活性元素引入方式,提出一种新型活性TIG焊接方法—气体输送活性钨极氩弧焊,即GTFA-TIG焊(gas transfer flux activating TIG welding).该方法通过保护气体将活性剂输送到TIG焊电弧—熔池耦合系统中,使得电弧收缩或熔池金属表面张力温度系数改变,能显著增加不锈钢、铝合金等金属材料的TIG焊熔深,保证焊缝表面成形良好,而且省去活性剂涂覆工序,减少活性剂消耗,实现焊接过程的全自动化.     

低合金钢Q345的深熔TIG焊研究

针对8 mm厚Q345低合金钢的深熔TIG焊中焊接电流、焊接速度、保护气体流量对Q345焊缝成型的影响进行了研究,并对成型较好的焊接接头进行了硬度测试和金相观察.试验结果表明,虽然深熔TIG焊在对低合金钢焊接时的焊接参数不稳定,焊接窗口较窄,不易形成良好的焊缝.但在适当的焊接条件下,可以实现深熔TIG焊对8mm厚Q345的一次性单面焊双面成型,焊缝性能较好并且成型良好的焊缝区组织由铁素体和少量针状贝氏体组成,焊缝熔合区和热影响区的硬度较母材上升了50%,无软化现象.具有继续研究深熔TIG焊应用于低合金钢Q345的意义.     

铝合金交流A-TIG焊中活性剂和焊接参数对焊缝熔深的影响

研究了铝合金交流A TIG焊中单组分活性剂对焊缝熔深的影响,还针对多组分活性剂研究了焊接参数对焊缝熔深的影响.实验结果表明,卤化物几乎不能增加焊缝熔深,而氧化物对焊缝熔深的影响很复杂,有的能增加焊缝熔深,有的效果不明显,有的甚至减小焊缝熔深.其中SiO2增加熔深作用最显著.焊接参数包括焊接电流、焊接速度、氩气流量和电弧长度等对焊缝熔深有一定影响.     

活性剂对钛合金A-TIG焊缝成形的影响

针对8 mm厚的TC4钛合金平板,选用MgF2、NaF、MnCl2、MgCl2、CaF2、re、KF、NaCl、ZnF2、CrCl3等10种单组份活性剂进行A-TIG焊接,通过与常规TIG焊对比,研究不同活性剂对焊缝成形的影响.试验结果表明:10种活性剂都能增加焊接熔深,其中CrCl3和Te粉可使焊接熔深达到常规TIG...     

均匀设计法在铝合金A-TIG活性剂配方研制中的应用

针对传统铝合金TIG焊熔深较浅的弱点,选用SiO2,Al2O3,MgO,TiO2,NaCl和CaF2等常见的氧化物和卤化物作为基础活性剂,研究了它们对铝合金TIG焊焊缝熔深的影响规律.在此基础上,利用均匀设计法进行了铝合金A TIG活性剂配方的研制,使得试验次数大大减少,焊缝熔深达到传统TIG焊的3倍以上.     

活性剂对铝合金电子束焊的影响

为了研究铝合金焊缝熔深增加机理，利用电子束散焦焊的焊接方法对铝合金LF21进行了焊接．以SiO2和V2O5作为表面活性剂，研究了活性剂对铝合金LF21电子束焊接的影响．研究结果表明，SiO2、V2O5对焊缝成形的影响是不同的，其中在SiO2作用下焊缝表面成形美观；在V2O5作用下焊缝成形变差．在SiO2、V2O5作用时，与A-TIG焊焊缝的熔深明显增加、熔宽稍有减小的情况相比，SiO2和V2O5对电子柬焊的焊缝熔深与熔宽的影响不大，表明了表面张力梯度改变理论对铝合金活性焊的作用不明显．     

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