论在自动式轧管机组上轧制钢管的壁厚不均匀性

钢管的壁厚不均匀值是钢管生产中的重要质量指标之一。 在轧制中所出现的无缝钢管的壁厚不均匀性,使降低钢管的壁厚公差造成困难,因而使大量金属流于浪费,加重了机器制造工业的金属车削负担。尤其是作为冷轧、冷拔钢管坯料的热轧无缝钢管,它们的壁厚不均匀值更具有重大的影响。这是因为在钢管冷轧冷拔的过程中,原始的壁厚不均匀性很难加以全部除去。相反的,在冷轧冷拔钢管生产中由于管壁减薄甚多,因此在某些情况下在成品钢管中壁厚不均匀的相对值反而有所增高。这就对于特薄钢管的轧制,以及对于要求有高度精确性的特种钢管的轧制造成极大困难。     

液压缸筒用热处理双相钢管研究

研究了液压缸筒用热处理双相钢管的力学性能和爆破性能，试验结果表明：热处理双相钢管经精密冷拔后制作液压缸筒，强度高、韧性好，爆破压力也主同，并且生产工艺简单，成本低，它可代替调度钢管用作煤矿液压支柱油缸等液压缸筒。     

管坯切断长度对冷拔管生产成本的影响

建立了冷拔钢管管坯下料长度的数学模型,用ＣＡＣＰＰ软件系统研究了管坯长度对钢和生成本的影响。     

GCr15轴承钢管冷拔横裂原因分析

通过材质分析、金相组织分析、球化机理的探讨及对球化工艺过程的追溯 ,得出GCr15轴承钢管冷拔产生横裂的主要原因是由于炉温不均、局部加热温度偏低而产生的球化退火欠热型反常组织在冷拔过程的复杂应力作用下产生裂纹所致。     

我国某车间钢管冷轨机Хпт-32工作孔型分析

目前,高质量和高合金的薄壁钢管,已经广泛地用于飞机,汽车拖拉机制造,仪器制造,锅炉制造及其他尖端科学技术中,而生产这些钢管的方法除了我国已经广泛使用的冷拔以外,最先进和最有效的是冷轧。     

厚壁钢管在冷拔过程中出现横裂缺陷的原因分析

本文通过对冷拔过后在35钢钢管外表面所产生的横裂缺陷结合实际生产流程进行分析,研究了出现横裂的原因。结果表明:管坯在加热环节如果升温速度过快、保温时间不够便会导致穿轧后的厚壁管在壁厚方向上呈现晶粒度及组织的不一致,近而在冷拔过程中出现显微变形差异,聚集到一定程度便会释放形成横裂。     

相似理论在钢管冷拔计算机仿真中的应用

以中式模短芯棒拔制过程为例,探讨了相似理论在钢管冷拔计算机仿真中的应用,利用大型百线性有限元程序ＭＡＲＣ／Ａｕｔｏｆｏｒｇｅ在计算机上对其进行了大量模拟,获得了具有实用价值的数学模型。     

异形钢管固定模拔制力公式的探讨

根据金属塑性变形原理,用金属弯曲变形的公式和冷拔原理的力学状态,推导出异型钢管固定模拔制力公式 P=(A_(??)-2R)Sσ_(?)/4sina k(P_0-P_1)通过实际测试表明,该公式基本可行。     

负载性质及输出功率对声共振频率的影响

在各种超声波加工中,为了充分利用超声功率,要求激励频率必须与机械传声系统固有频率重合。最近在有些超声波加工中,已采用了自激频率跟踪发生器[1][2],它能在有载传声系统共振频率发生偏移时,自动跟踪之。 在超声波冷拔工艺中:负载性质如何,对传声系统共振频率有何影响;激励状态及功率对频率有何影响以及频率偏移对效果有何影响?为此,我们对超声冷拔铝管、钢管、紫铜管、黄铜管、钢丝进行了广泛的实验研究,并获得了一些实际结果。试验得出,在超声振动外模拉拔工艺条件下,频率偏移很小,可不采用频率自动跟踪系统。     

在拨管过程中应用超声振动

提高拔制过程的效率和钢管质量可通过采用冷拔工具的超声振动来达到。工业上采用这个方法必须确定合理的工艺设备结构、各道次的残余应力和在稳定拨制过程中拔机参数的匹配;要研究拔制过程的力能参数和制定采用超声振动拔管的最佳拔制工艺。     

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.     

Design and analysis of generic LBS application developing platform

Location based services is promising due to its novel working style and contents.A software platform is proposed to provide application programs of typical location based services and support new applications developing efficiently. The analysis shows that this scheme is easy implemented, low cost and adapt to all kinds of mobile nework system.     

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