城市燃气输配管道完整性管理探究

简述了燃气输配管道完整性管理的概念及使用过程,介绍了燃气输配管道完整性管理的方法,分析了城市燃气输配管道完整性管理的关键点。     

进一步完善合肥市城市天然气输配系统的设想

2003年西气东输以来，合肥市燃气已形成一定的输配调峰规模。文章分析了合肥市城市燃气输配系统的现状及存在的问题，结合合肥市发展规划，提出了进一步完善合肥市燃气输配系统的建议和措施。     

城镇管道燃气漏气事故分析及对策

介绍了2015年和2016年太原市城镇燃气输配系统事故的基本情况,分析了事故产生的主要原因,提出了相应的解决措施,希望以此加强燃气系统的安全管理,达到控制或减少燃气泄漏、中毒、火灾、爆炸等事故的发生。     

聚乙烯燃气管道施工技术的探讨

本文结合作者在管道燃气工程施工、运行过程的实践经验,探讨PE燃气管道施工技术及应用。聚乙烯（PE）管道是以高密度聚乙烯为原料生产的管道输配系统,是城市供水及燃气输配管网领域中的一项管材新产品。     

城市燃气管网负荷预测方法

城市燃气管网负荷预测是制定城市燃气建设规划、确定燃气生产企业大、中修计划以及燃气输配企业科学调度的重要依据,本文结合我国城市燃气生产、输配管理的现状，介绍几种目前常用的城市燃气管网负荷预潮方法，并评述了各自的优势和缺陷。     

浅谈山西省燃气系统的改造

分析了主要以焦炉煤气为主的原有城市燃气与天然气在诸多性质上的区别,根据燃气系统改造的原则,提出了燃气系统的置换方式及输配系统、调压设施、燃气用具等的改造方法。     

秦皇岛市燃气管网地理信息系统的应用

鉴于秦皇岛市燃气公司对燃气管道信息化的迫切需要,我们选用地理信息系统实现了燃气管网的动态管理。该系统具有燃气管网的规划设计、输配管理、图档管理、抢修辅助决策、燃气用户管理及综合查询、统计等功能,各管网相关部门可以实现在各自部门同时查阅管网信息,提高了管网信息利用效率。     

上海城市燃气输配管网失效模糊故障树分析法

采用故障树法,对引起上海城市燃气输配管网失效的各个因素进行系统分析,建立上海城市燃气输配管网失效故障树.通过该故障树的定性分析,可得引起管网失效的27个最小割集;通过定量分析,则可以计算其顶事件的发生概率及进行底事件的重要度分析.采用专家调查和模糊集理论相结合的方法,评估故障树底事件发生概率的模糊性,并以上海城市燃气输配管网故障树系统中的“杂质堵塞”这一底事件为例,计算出其模糊失效率为0.0048.     

GIS系统在城市燃气管网中的应用

随着城市燃气管网规模的不断扩大,人工绘制管网竣工图速度慢,时效性差的弊端日渐显露,传统落后的人工管理方式,与城市燃气发展前景矛盾日益突出.GIS系统(地理信息系统:Geographic Information System,简称GIS)的应用改变了燃气管网传统落后的人工管理方式,实现了燃气管网规划、设计和管理的科学化、规范化、自动化,同时也为燃气的输配调度、图档管理、管网规划、管网抢修决策、日常运行管理、施工管理以及综合辅助决策等提供了现代化处理手段.GIS系统作为燃气综合管理信息系统的重要组成部分,它的投用进一步推动了燃气企业信息化建设的进程.充分体现了企业的现代化管理水平.     

城市燃气管网负荷预测方法

城市燃气管网负荷预测是制定城市燃气建设规划、确定燃气生产企业大、中修计划以及燃气输配企业科学调度的重要依据.本文结合我国城市燃气生产、榆配管理的现状,介绍几种目前常用的城市燃气管网负荷预测方法,并评述了各自的优势和缺陷.     

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     

On the Thermodynamic Limit for Responses to Static Electromagnetic Fields

For molecular systems,the quantum-mechanical treatment of their responses to static electromagnetic fields usually employs a scalar-potential treatment of the electric field and a vector-potential treatment of the magnetic field.Although the potential for each field separately is associated with the choice of an(unphysical)origin,the precise choice of the origin for the electrostatic field has little consequences for the results.This is different for the