超声波探伤检测的影响因素分析及监督与控制

由于石油管道其所处工况和环境相对恶劣,易泄漏甚至爆炸,因此石油管道焊缝无损检测是石油管道的重要课题。介绍了超声波探伤检测技术的基本原理,详尽地分析了影响野外超声波探伤质量的原因。和其他的无损探伤检测方法相比,超声波探伤检测成本低、检测速度快,并且能及时检测出焊缝内部质量的缺欠。最后对一个实例进行了分析,并且针对监督检查超声波探伤提出了相应的措施。     

基于虚拟仪器的齿轮超声无损探伤技术的应用研究

提出用基于虚拟仪器的无损超声探伤技术来实现工业上高效快速地对产品进行合格检验的探伤系统的设计方法.通过Labview软件平台设计出超声探伤系统,达到对机车齿轮在无人值守的情况下全自动地进行超声波无损探伤的过程,并给出探伤结果.介绍了系统的原理和软硬件结构.     

综述压力容器超声波探伤检测的技术问题

近年来,随着高科技手段快速的发展,超声波检测技术作为无损检测技术的重要手段之一,在其发展过程中起着重要的作用,它提供了评价固体材料的微观组织及相关力学性能、检测其微观和宏观不连续性的有效通用方法。超声波探伤广泛应用于锅炉和压力容器制造等领域常规超声波探伤的基本模式即A型显示的脉冲回波法在检测缺陷时通过缺陷回波的辐值大小来判断缺陷是否应该判废。本文主要讨论了压力容器超声波探伤检测相关技术,希望能够促进压力容器超声波探伤检测技术的发展。     

针对T型接头对接焊缝的超声波探伤工艺研究

从目前T型接头对接焊缝来看,最有效的探伤方式是超声波探伤。超声波探伤具有对工件无损伤、便于操作、无辐射安全性高等特点,在目前处理特殊工件探伤时得到了重要应用。从探伤方法上来说,超声波探伤与射线探伤、渗透探伤、磁粉探伤等属于主要的探伤方法,在探伤效果上,由于超声波的声波特性,探伤效果较为准确,并且执行起来只需要超声波探伤仪即可。随着超声波探伤仪的技术升级,超声波探伤成为了未来探伤的重要方式之一。基于这些优点,超声波探伤仪在复杂焊缝上的探伤中得到了重要应用,特别是在T型接头对接焊缝探伤中取得了预期效果。     

超声波在流量测量技术中的应用

1　前言超声波是一种机械波 ,它方向性好 ,穿透力强 ,遇到杂质或分界面会产生显著的反射。利用这些物理性质 ,可把一些非电学量参数转换成声学参数 ,通过压电元件转换成电量 ,这样就可以通过超声波传感器进行无损探伤、测量厚度、流速、流量、密度及液位等。本文仅对超声波在流量测量技术方面的应用作以介绍。2　超声波的激发与接收超声波换能器也称为超声波探头 ,即超声波传感器。可以利用压电材料的逆压电效应制成超声波发射头 ,利用压电效应制成超声波接收头。由于压电效应的可逆性 ,在实际使用中 ,有时用一个换能器兼作发射头和接收头。…     

浅谈小径管超声波探伤

火力发电厂锅炉受热面管子对接焊缝的无损检测过去一直采用射线探伤,但射线探伤存在以下几个问题:焊缝中裂纹、未熔合等面积型缺陷检出率低,容易漏检、工序多、工效低、劳动量大,难以保证工程进度。且射线对人体有害,与其它工种不能交叉作业、成本大、材料消耗高。所以采用对小径管,本文考虑采用超声波探伤。     

一体化教学模式在超声波探伤中的应用

本文论述了一体化教学模式在超声波探伤中的应用,重点接受了超声波探伤一体化教学的目标和具体的实施过程.     

对小径管焊缝的超声波检测探析

本文针对检测锅炉小径管焊口内部质量时超声波的应用进行了分析和探讨。具体论证了在小径管对接焊缝探伤中的超声波探伤工艺。     

矿山绞车车轴超声波检测方法的探讨

绞车在我国矿山各种大型设备中的数量较多、应用比较广泛的一种矿山设备。而绞车的车轴则是绞车的关键部件,能否安全完好地生产运行将直接关系到矿山安全生产运行的重大问题。如何在不影响矿山正常生产运行的前提下,使用科学的、完善的无损探伤检测手段,从而达到检测矿山绞车的目的呢？本文应用西山矿物局机电总厂现有的CT-8C探伤机先后在西山矿物局白家庄矿、酉铭矿、杜尔坪矿、官地矿以及镇城底矿、马兰矿、西曲矿等地。对不同型号的绞车轴进行了超声波探伤。摸索了一套行之有效的绞车轴的无损探伤检测方法,为该局设备正常、安全的生产运转提供了相关信息。并直接作为该局大型设备安全运转、维修的依据,为其安全生产运行提供了关键的安全保证。     

新型镶圈活塞超声波自动检测系统

采用超声波无损探伤和计算机技术，利用双路通道自动检测镶圈活塞上镶圈与基体之间的结合缺陷。该检测系统功能强、精度高、操作方便、可靠性好，且测试结果具有良好的重复性。该检测设备已投入现场使用。     

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.     

Characterization of Ordovician carbonate reservoirs, southeastern Saskatchewan, Canada

The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3～4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰～ -7.8‰, PDB) and matrix dolomites (-6.6‰～ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084～0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078～0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.     

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.     

A computer generator for randomly layered structures

AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…     

An Index mechanism for multi-scale view in spatial databases

There are numerous geometric objects stored in the spatial databases. An importance function in a spatial database is that users can browse the geometric objects as a map efficiently. Thus the spatial database should display the geometric objects users concern about swiftly onto the display window. This process includes two operations:retrieve data from database and then draw them onto screen. Accordingly, to improve the efficiency, we should try to reduce time of both retrieving object and displaying them. The former can be achieved with the aid of spatial index such as R-tree, the latter require to simplify the objects. Simplification means that objects are shown with sufficient but not with unnecessary detail which depend on the scale of browse. So the major problem is how to retrieve data at different detail level efficiently. This paper introduces the implementation of a multi-scale index in the spatial database SISP (Spatial Information Shared Platform) which is generalized from R-tree. The difference between the generalization and the R-tree lies on two facets: One is that every node and geometric object in the generalization is assigned with a importance value which denote the importance of them, and every vertex in the objects are assigned with a importance value,too. The importance value can be use to decide which data should be retrieve from disk in a query. The other difference is that geometric objects in the generalization are divided into one or more sub-blocks, and vertexes are total ordered by their importance value. With the help of the generalized R-tree, one can easily retrieve data at different detail levels.Some experiments are performed on real-life data to evaluate the performance of solutions that separately use normal spatial index and multi-scale spatial index. The results show that the solution using multi-scale index in SISP is satisfying.     

Jane Eyre——A Feminist In The 19th Century

In the 19th century the society was controlled by men, and women were just appendants of them, they had not any rights and freedom. But Jane was an exception, she showed some characteristics of early feminist. Jane showed her characteristics of feminism in three aspects: rebellion, equality, and independence. These characteristics were helpful to her success, and feminism is the only way out for women of that time.     

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-