宁化第一废热锅炉管束的修复

本设备为宁化30万吨/年合成氨装置的重点关键设备.该设备能否正常使用关系到宁化合成氨装置的运转情况.作为大型进口设备,该设备的修复过程比较复杂,要求比一般三类容器苛刻,检验过程控制严格.同时,修复厂家必须有严格的质保体系来跟踪修复过程,从而保证修复质量.……     

宁化第一废热锅炉管束的修复

本设备为宁化30万吨/年合成氨装置的重点关键设备.该设备能否正常使用关系到宁化合成氨装置的运转情况.作为大型进口设备,该设备的修复过程比较复杂,要求比一般三类容器苛刻,检验过程控制严格.同时,修复厂家必须有严格的质保体系来跟踪修复过程,从而保证修复质量.     

渤海油田聚驱采出液处理设施分析对比

渤海海域3个注聚开发油田都遇到了含聚采出液处理技术瓶颈,在采取设备改造、工艺参数优化、化学药剂优选等措施后,解决了原油处理过程中含水偏高的问题,但油田生产水过滤器维护频率高、注水水质不稳定等问题仍然困扰着油田的正常生产.通过对比渤海油田中心平台(CEP)和浮式生产储卸油装置(FPSO)两种开发设施的典型工艺流程,发现在...     

矿用掘进机伸缩机构的故障诊断及优化

掘进机是煤矿生产作业中不可或缺的重要机械设备,它的能效高低直接关系到煤炭产量,一旦掘进机出现故障,会严重影响井下正常生产作业。针对以前掘进机伸缩部在实际使用过程中暴露出的一些问题,从矿用设备多级伸缩机构的故障诊断与预防措施入手,对矿用设备的多级伸缩机构进行了优化设计。通过对掘进机伸缩油缸、伸缩部主轴承等进行改进,使其结构更合理,性能更优越。     

浅谈金属波纹管伸缩节在水利工程管道中的技术应用

压力管道是水利倒虹吸工程和电站工程的重要组成部分,在压力管道较长压力较大时,伸缩节数量较多,设计安装制造技术难度也较大,运行期间机修周期长,金属波纹管伸缩节应用可以免除上述困难和缺点,同时节约投资。目前由专业厂家制造的金属波纹管伸缩节已在压力钢管上使用获得成功。     

海上平台磁致伸缩液位计变送器信号跳变故障分析与处理

磁致伸缩液位计精度高、可靠性强、安全性好,被广泛应用于石油化工、水力发电等行业进行液位测量和监控.某海上油田平台长期使用的磁致伸缩液位计出现液位跳变故障,给油田设备稳定运行带来了隐患.对出现跳变故障的液位计的信号进行收集和比较,通过分析液位计变送器的信号故障对关键参数配置进行合理调整,降低了磁致伸缩液位计跳变故障发生的...     

大功率电机启动瞬间变频器停运的原因

在油田和输油企业电力系统中，大功率电机普遍存着启动瞬间会产生电压大幅度的降低，导致低压设备的低电压保护动作，引起设备停运或故障，影响正常的油田生产和设备正常运行。本文主要从生产实际问析题入手，通过对大功率电机启动过程中，各点等级电压变化情况进行分析，寻求解决问题最佳方法。     

LDB-102 DME接收机译码的处理以及译码中问题的探讨

澳大利亚INDRA公司生产的测距仪设备(LDB-102 DME)在中南地区的机场及空管导航台站都有着广泛的使用,因此对于该设备的信号处理进行研究和探讨有助于设备维护人员深入掌握设备原理,在故障发生时可以更快地判断故障原因并及时处理。本文主要分析LDB-102 DME设备的接收机视频板,希望通过介绍该板的系统译码处理过程,理清信号的处理流程,同时模拟一些不正常询问,进而分析系统译码存在的问题,为日后设备维护人员及厂家技术人员提供技术上的分析。     

延长减速器运行周期浅析

搅拌器是化工厂常见的设备，其中大部分搅拌需要借助减速器将电机转速调至符合工艺要求值。当减速出现故障时，搅拌将不能正常工作，从而导致设备停产或装置减产或停产。本文从减速器润滑管理角度出发，分析了常见的润滑不到位导致故障的原因，并找到相应对策。通过实践证明，设备润滑得到充分保证后，设备维修量减少，减轻工人劳动强度。杜绝了设备润滑事故，生产平稳运行得以保障。     

油田泵类设备机械密封腐蚀失效分析

泵类设备在油田广泛使用,其结构设计常采用机械密封。在使用过程中,如果机械密封失效,轻则泄漏,重则设备的运转率急剧下降或造成设备的运转故障,严重的还会造成设备事故。分析了泵类设备机械密封腐蚀失效的原因和特征,对密封件腐蚀失效进行了分类,并列举了一些工程腐蚀失效实例,提出了泵类设备机械密封抗腐蚀的具体技术措施。     

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