谈矿井提升机的保护装置

提升装置能否做到安全运转,安全保护装置将起到十分重要的作用。提升装置的安全保护装置主要包括制动装置、微拖动装置、防止过卷装置、防止过速装置、深度指示器、闸瓦过磨损保护装置、过负荷和欠电压保护装置等。     

谈矿井提升机的保护装置

提升装置能否做到安全运转，安全保护装置将起到十分重要的作用。提升装置的安全保护装置主要包括制动装置、微拖动装置、防止过卷装置、防止过速装置、深度指示器、闸瓦过磨损保护装置、过负荷和欠电压保护装置等。     

天车智能防碰装置在渤海油田的推广应用

天车防碰系统是海洋钻修机运行过程中非常重要的安全装置,在钻井、修井作业过程中起着致关重要的作用。普通天车防碰系统只是通过一个简单的过卷阀来控制刹车,一旦管路老化或破裂则不能正常使用,并且普通的天车防碰系统只能防止游车大钩上碰天车,不能防止游车大钩下落砸伤设备和人员。智能型天车防碰系统则采用了过卷阀和电磁阀双重保护,防止大钩上碰下砸,同时具有声光报警功能,防止大钩下落过快的减速装置等安全措施,提高了钻修机在操作过程的安全系数,在渤海油田现场应用中发挥了很好的作用。     

如何正确选用爆破片

爆破片装置作为压力容器的安全附件之一,广泛应用于石油及化工行业,是保证压力容器安全运行,防止发生超压爆炸的一种保险装置.正确选用和使用爆破片装置,对于保护容器不发生超压变形或爆炸,维护设备安全具有十分重要的意义.     

三相分离器蒸气减压系统的应用

介绍了一种用于三相分离器容器保护的蒸气减压系统的设计应用,实现了在火灾工况下对容器壁的保护,此蒸气减压系统可在有效的时间内将容器的压力降到安全值,防止容器破裂,而且即使容器破裂,也可以防止其可能向火源增加更多的燃料,从而很好地保护了容器和周边装置的安全,此蒸气减压系统由紧急放空阀和多级限流孔板组成。     

基于单片机的智能充电控制器的设计与应用

根据锂电池充电的特点,结合市面上常用充电器本身存在的缺点探讨一种新型的采用单片机控制的智能型充电控制器的设计与应用,该装置具有智能控制充电进程,智能判断充电终止状态,有效防止锂电池的欠充或过充,具有高效安全的充电控制和保护功能.     

矿山液压提升机的安全功能及其安全隐患探讨①

液压提升机的防爆,提升过程中的超速、过卷保护,液压系统的高、低压保护及升降与制动工作协同性是安全性设计的核心与关键。介绍了液压提升机的主要安全保护功能,并探讨了液压提升机存在的安全隐患与对策。     

TRICON SIS系统在重油催化裂化装置的应用

安全仪表系统SIS(Safety Instrumented System)是一种独立于生产过程控制系统的安全联锁保护系统。它可以保护由于工艺生产故障、仪表故障、系统供电故障等对生产装置造成的重大危害,保证生产装置能够安全运行。针对TRICON SIS系统在炼厂重油催化裂化装置中的应用,重点介绍了TRICON系统的硬件结构、系统组态、逻辑编程、人机界面组态和系统维护等。     

石化装置中的安全保护系统

石化装置的原产品一般都属于易燃、易爆或有毒介质,生产过程稍有闪失就会酿成灾难性的事故,造成生产、设备、人员等方面的重大损失,把安全作为生产的前提是大家的共识,当生产出现异常时,通过安全联锁保护系统,使装置局部或全部停车,防止发生装置爆炸、着火、人员伤亡、中毒以及其他生产事故是生产的重中之重。     

一种新型电气化铁路串联电容器保护间隙

随着电气化铁路的不断发展,串联电容器补偿装置在牵引供电系统中得到广泛应用,而电容器的过压能力较弱.提出了一种新型保护间隙装置,当发生过电压时,通过触发电路迅速启动.本装置能较好的满足电容器的过压保护要求,并在实际运行中取得了较好效果.     

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.     

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     

Call for Papers

<正>"The Journal of Shanghai Normal University:Mathematics"is published by Shanghai Normal University as regular issues of The Journal of Shanghai Normal University each year from 2014 in English.The editors-in-chief of the issues are professors Yuhao Cong and Maoan Han.The Journal of Shanghai Normal University was started in 1958 with     

Journal of Donghua University ( English Edition) Contents of Volume 31

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Brief Introduction to “Journal of Jilin University( Science Edition) ”

<正>"Journal of Jilin University(Science Edition)"is a comprehensive academic journal in the fields of science sponsored by Jilin University and administrated by the Ministry of Education of the Peoples Republic of China.The journal started publication in 1955.The original name at starting publication was"Journal of Natural Science of Northeast People University",which was changed into"Acta Scientiarum Naturalium Universitatis Jilinensis"in 1958 owing to the name change of the university.The present journal name has