奥里油锅炉高温腐蚀的混沌预测

奥里油中含钒量较多,是锅炉预防高温腐蚀设计中的大难题.文中针对奥里油钒高温下的腐蚀机理,运用混沌理论,建立基于最大Lyapunov指数的腐蚀预测模型,并以电阻探针测得某输油管道内的高温腐蚀深度数据,对所提出的腐蚀预测模型进行校验.预测与评估结果显示:腐蚀深度误差均小于6%.平均误差为3.58%,预测精度较高,表明所提出的预测模型可以有效预测金属的高温腐蚀状况,为奥里油钒的高温腐蚀预测提供理论依据.     

双盘外浮顶原油储罐组装要点

目前。现场组装大型金属原油储罐,基本上采用内脚手架正装法和水浮正装自动焊法两种方法,在惠州炼油项目原料罐区建设中,8台10×104m^3（Ф80000×21800）双盘外浮原油储罐就是采用内脚手架正装法现场组装,各储罐第一圈壁板到第六圈壁板采用高强度钢板08MnNiVR,罐壁第一圈为带开孔的壁板,采用高强度钢板08MnNiVR-SR,第八圈、第九圈采用国产Q235-B铜板,两者之间第七圈的焊接采用低合金钢板16MnR过渡：罐底弓形边缘板采用高强度钢板08MnNiVR-SR,罐底中幅板、浮顶用铜板采用Q235-B,抗风圈、加强圈及其它附件结构以Q235-B材料为主。     

腐蚀管线的剩余寿命预测

预测管线的腐蚀变化趋势及腐蚀对管线结构完整性的危害是评价管线剩余寿命的关键步骤。将影响管线剩余寿命的各种因素看成是分布各异的随机变量 ,建立了预测管线失效的概率数学模型。利用这一模型 ,研究了腐蚀速率、缺陷深度、管道壁厚和工作压力等因素对管线可靠性的影响。结果表明 ,各参数的不确定性越大 ,管线的可靠性越低 ;缺陷深度在腐蚀缺陷形成初期 ,对管线的可靠性有很大影响 ,而随着时间的推移 ,腐蚀速率将对管线的可靠性有较大影响。对一条输油管线 ,基于管线腐蚀检测数据 ,对 1km长度的管道进行失效概率统计分析得到的腐蚀速率能够对管线全线的安全状况做出合理预测 ,从而为管线的进一步维修与检测提供参考资料。     

基于Gumbel极值分布的大型原油储罐剩余寿命预测

储罐的剩余寿命是预测储罐的未来工作能力,预测储罐未来腐蚀发展趋势和壁厚减薄趋势。预测其在满足剩余强度及其安全性要求前提下储罐的剩余寿命。根据储罐的腐蚀特点,储罐的最大腐蚀坑深服从Gumbel I型最大极值分布。基于最大极值分布和概率统计,推导出储罐剩余寿命计算公式。储罐的剩余寿命由储罐中幅板的剩余寿命决定。分别采用API653和API 650的规定确定罐底板和罐壁板的最小允许厚度。在0.99、0.999和0.999 9的可靠度下储罐A的剩余寿命分别为25年、20年和17年。与国外标准进行对比,国内标准对储罐检修周期的规定相对保守。提出的剩余寿命预测方法对于确定储罐检修周期具有参考价值。     

局部腐蚀油气管道失效压力计算方法

利用管道应力集中理论,以数值模拟数据为基础,建立一种局部腐蚀油气管道失效压力的计算方法。验证非线性有限元法评价局部腐蚀的可靠性,用该方法分析局部腐蚀半径及局部腐蚀深度对管道失效压力的影响;并与其他评价规范计算结果进行对比。结果表明,拟合得到的局部腐蚀油气管道失效压力计算方法的误差小,误差分布均匀,可以满足局部腐蚀油气管道失效压力的预测要求。     

局部腐蚀油气管道失效压力计算方法

利用管道应力集中理论,以数值模拟数据为基础,建立一种局部腐蚀油气管道失效压力的计算方法。验证非线性有限元法评价局部腐蚀的可靠性,用该方法分析局部腐蚀半径及局部腐蚀深度对管道失效压力的影响;并与其他评价规范计算结果进行对比。结果表明,拟合得到的局部腐蚀油气管道失效压力计算方法的误差小,误差分布均匀,可以满足局部腐蚀油气管道失效压力的预测要求。     

储罐直径对罐壁腐蚀缺陷的漏磁场信号影响分析

受腐蚀因素影响,储罐易发生腐蚀泄漏,储罐罐壁腐蚀一直是无损检测的难点,本文开展罐壁腐蚀缺陷漏磁检测技术研究。在轴向磁化方式下,对储罐壁板缺陷进行漏磁检测时,受壁板直径影响,同一缺陷处不同检测通道的漏磁信号不同,分析各通道漏磁信号与储罐直径的关系,得出直径与各通道漏磁信号峰值的数学模型;在此基础上对各通道漏磁信号进行预处理,建立修正系数,以消除不同通道之间的漏磁信号差异,实现各通道信号均匀化。     

腐蚀管线的剩余寿命预测

预测管线的腐蚀变化趋势及腐蚀对管线结构完整性的危害是评价管线剩余寿命的关键步骤。将影响管线剩余寿命的各种因素看成是分布各异的随机变量，建立了预测管线失效的概率数学模型。利用这一模型，研究了腐蚀速率、缺陷深度、管道壁厚和工作压力等因素对管线可靠性的影响。结果表明，各参数的不确定性越大，管线的可靠性越低；缺陷深度在腐蚀缺陷形成初期，对管线的可靠性有很大影响，而随着时间的推移，腐蚀速率将对管线的可靠性有较大影响。对一条输油管线，基于管线腐蚀检测数据，对1km长度的管道进行失效概率统计分析得到的腐蚀速率能够对管线全线的安全状况做出合理预测，从而为管线的进一步维修与检测提供参考资料．     

大型储罐壁厚计算的探讨分析

1　前言储罐的设计越来越趋向大型化 ,能够合理、科学、安全地设计、制造和使用大型储罐 ,显得越来越重要。本文就大型储罐壁厚的计算 ,从计算方法、操作和充水试验时的许用应力、焊缝系数的选取等几个方面对中国标准ＳＨ3 0 46和美国标准ＡＰＩ65 0进行了分析和比较。2　设计计算方法ＡＰＩ65 0中储罐壁厚计算有两种方法 ,“一英尺”法和变设计点法。“一英尺”法 ,是以高出每圈壁板下端 0 .3ｍ (约为一英尺 )处作为一个固定的设计点进行计算。用“一英尺”法计算壁厚时 ,对直径较大的储罐 ,壁板的实际应力与许用应力相差较大。一般情况下 ,最下两圈壁板的实际应力接近按 2 /3屈服点取的许用应力或略有超过 ,而上面几圈壁板的实际应力均比许用应力小 ,显得有些保守 (最上面几圈壁板的名义厚度不是计算壁厚所确定 ,而是由刚度等因素所决定 ,本文所述不涉及这几圈壁板。以下同 )。变设计点法是以壳体的弹性移动为基础 ,这种方法考虑了罐底板的约束对罐壁受力的影响以及较厚的下层罐壁对较薄的上层罐壁的影响 ,从而使每圈壁板的最大应力点位置上移 ,其核心就是力求找出各层壁板的最大受力点 ,每一圈壁板都采用可变的设计点计算壁厚 ,...     

拱顶罐罐顶腐蚀数据的统计分析

为加强储罐的管理,准确把握储顶的腐蚀状态,对罐顶的健康状况进行分析评价。采用广义极值分布作为罐顶腐蚀深度的统计模型,对腐蚀深度最大值进行极值统计,构造实际问题的统计分析模型,并用L-矩法估计模型的参数,分析罐顶腐蚀的统计规律。对胜利油田某联合站5个拱顶罐罐顶腐蚀数据进行统计分析。结果表明,罐顶腐蚀最大深度符合广义极值分布的Ⅲ型分布(Weibull分布),经柯尔莫哥洛夫检验,极值Ⅲ型分布能较好地拟合罐顶的腐蚀深度。     

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