某一循环流化床锅炉Ⅱ级过热器管材失效分析

利用金相显微镜、扫描电镜(SEM)和定量光谱仪等对465 t/h循环流化床(CFB)锅炉Ⅱ级过热器管爆口进行了金相组织分析、宏观及微观形貌观察、材质化学成分以及结构和运行状况分析,探讨了过热器管材的失效原因和机理.结果表明,CFB锅炉内颗粒的冲刷与撞击造成过热器管屏的磨损,磨损引起的壁厚减薄是管材失效的主要原因,磨损机理主要是冲刷磨损和高温腐蚀相结合的冲蚀磨损;管子内压应力与管系应力加速了爆漏过程,是造成过热器管撕裂爆口的次要原因.     

锅炉对流过热器管爆漏原因

根据电厂670t/h锅炉对流过热器爆漏案例进行分析,及结合爆漏处割管取样进行分析,论证过热器磨损变薄、运行方式不合理及调整不及时管壁长期超温爆管的主要原因。     

屏式过热器“一管两爆”原因分析及对策

介绍了汕尾电厂1号锅炉屏式过热器在同一时间同一根管上发生两处爆管的事故。通过爆口宏观、化学成分、金相组织、扫描电镜、内窥检查等方法分析,认为导致爆管的原因为异物堵塞造成的长时超温,并提出了相应的解决措施。     

循环流化床锅炉炉内受热面磨损问题研究

循环流化床（CFB）燃烧技术以其优良的性能、低污染燃烧特性成为当今世界先进可靠的洁净燃煤技术之一。本文介绍了循环流化床锅炉炉内水冷壁管磨损机理以及水冷壁磨损的原因，最后对水冷壁管防磨措施进行了探讨。     

电厂锅炉设备中高温过热器爆管的原因以及防治措施

电厂锅炉设备作为影响机组安全运行以及电厂经济效益的重要环节,其突出的爆漏问题一直以来都是导致火电机组强迫停机的主要原因。为了从根本上结束电厂锅炉设备中高温过热器管事故的频发,文章首先从宏观检查、材质金相显微组织检验及力学性能分析几个方面分析了某高温过热管的爆管原因,最后又给出了相应的预防与处理措施。     

DG420/13.7-∏2型锅炉对流过热器爆管分析

针对广东省粤泷发电有限责任公司（罗定电厂）#2锅炉对流过热器管爆漏的原因进行调查分析。爆管主要是由于长期过热爆管,主因是管壁存在局部超温现象,超温引起管子组织老化,管子内产生蠕变孔洞及裂纹等缺陷引起的。     

SZL4－13锅炉水冷壁管环向裂纹产生原因分析

本文通过金相分析证实水冷壁管环向裂纹产生的原因是高温造成管材表面脱碳、组织粗化、强度降低，同时产生管内部腐蚀，在交变热应力循环下，在管外向火侧产生裂纹并向内扩展，最后形成穿透裂纹。     

15CrMo高温过热器弯管的失效分析

分析了75 t/h高压循环流化床锅炉用15CrMo高温过热器弯管在试运行近100 h下产生裂纹的原因.结果表明,由于炉水中氯离子含量超标以及停炉期间未进行保护,导致大量空气进入炉体,在高温、弯管自身高残余应力等综合作用下产生应力腐蚀,这是导致过热器弯管失效的主要原因.     

某发电厂两台锅炉同类型爆管原因分析

在试验的基础上,对某发电厂两台锅炉屏式过热器管发生同类型爆管的原因进行了分析,结果表明,原材料中存在夹杂物及焊接缺陷共同作用造成管壁温度升高及局部应力超限,最终引起屏式过热器爆管。     

氩弧制备熔覆层的性能及分析

循环流化床锅炉水冷壁管高温7中蚀磨损是目前阻碍循环流化床锅炉发展的主要技术难题。现在人们重点研究其磨损机理及有效的防磨措施。本文先分析了循环流化床锅炉水冷壁管磨损的失效机理，采用电弧喷涂合金涂层，并使用氩弧重熔技术制备得到了具有冶金结合的耐磨涂层，并对涂层进行了硬度实验及分析，高温冲蚀磨损试验及分析，显微组织分析。分析表明：熔覆层表面硬度高达1200HV，组织均匀，与基体之间冶金结合，并表明熔覆层的硬度是20G铜的6～7倍，耐高温冲蚀性能为20G钢的2．5～4倍。涂层的磨损行为介于塑性和脆性磨损之间，并以塑性磨损为主，具有良好的抗高温冲蚀磨损性能。     

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