温度对光缆中数字信号漂移特性的影响

在光缆传输系统中，环境温度的变化会使数字信号发生漂移，从而影响传输质量，在长途架空光缆传输系统中，这种影响最为严重。首先对影响光纤中数字信号漂移的因素进行分析，然后给出试验光纤的温度漂移特性的测试结果，并对试验数据进行了处理和分析．最后，对光缆中数字信号的温度漂移特性进行了讨论．     

光纤中信号漂移特性与误码间关系的模拟测量

长途架空光缆干线受环境温度的影响较大，因此光纤中传输的数字信号具有较大的漂移，为了研究这种漂移对系统误码率的影响，利用一种模拟技术获得日漂移量与误码的关系，从而为确定光缆的漂移温度系数提供了依据。     

主轴系统动态误差和热漂移误差的测试分析

主轴的动态误差和热漂移误差直接影响机床的定位精度和工件表面加工质量。运用API主轴动态误差及热变形分析仪和API主轴误差分析软件对加工中心的主轴进行动态误差和热漂移测试。通过测量系统采集到的机床主轴系统的温度变化及分布数据及主轴系统的热变形数据,可以了解及掌握机床在运转过程中主轴系统的实际工况,如热平衡时间、主轴系统不同时刻在各方向的变形量等信息,对以后主轴系统的优化设计和动态补偿提供了基础数据支撑。     

光缆线路故障测量与定位模拟训练系统设计

介绍了一种采用虚拟仿真技术和实物模拟相结合的光缆线路故障测量与定位训练系统设计方法。系统应用三维虚拟仿真技术来实现光缆线路路由的呈现、故障生成,对于故障出现后的告警状态、光缆故障测量和测量结果显示又采用实物形式模拟。训练时可以在虚拟场景中生成光缆线路故障,无需专用线路训练场地和对实际光缆线路的破坏,降低了光缆故障测量与定位技能训练门槛。     

通信光缆线路监测维护系统应用的探讨

介绍了通信光缆线路采用维护监测系统的目的,目前使用方式存在的不足以及增加相应的光缆外护套对地绝缘电阻自动监测系统来提高光缆线路维护的水平和延长光缆运行的寿命以及完善监测系统的方式。     

浅谈直埋光缆线路的建设与维护

随着光缆在电力调度通信系统方面的应用和普及,光缆线路建设与维护工作也日益重要,本文对直埋光缆线路建设、验收、维护、线路中断的整治进行了详尽的论述、供同行参考。     

基于机器视觉的大跨长联桥上无缝线路小阻力扣件纵向服役状态监测研究

以福厦高铁渔溪特大桥为例,提出一种基于机器视觉的小阻力扣件纵向服役状态监测方案,以获取大跨长联桥上无缝线路钢轨纵向变形与复合垫板窜出的时变特征;同时,结合梁轨温度与梁端位移测试结果,分析梁体温度、钢轨温度、梁端累积位移、梁轨相对位移与垫板窜出量之间的相关性。研究结果表明：根据图像识别结果,钢轨在监测阶段将随温度变化产生不同方向的伸缩,且钢轨位移略大于垫板窜出量。钢轨昼夜温差要显著大于桥面气温以及连续梁梁内气温、顶板温度、腹板温度,且梁体温度变化幅度显著比钢轨的小,其原因在于钢轨的比热容较小,在同等热量输入输出时产生的温度变化幅度较大。梁端纵向位移随温度变化幅度较小,最大日位移为0.15 mm;在监测周期内,梁端累积位移呈波动减小趋势,即梁体发生了缓慢收缩,其原因在于夏季到秋季时气温逐渐降低,且最大平均位移变化速率为0.09 mm/d。梁体温度、钢轨温度、梁端累积位移、梁轨累积相对位移和垫板窜出量之间的相关系数均大于0.8,说明其相关性较大,且均呈较好的正相关关系。通过基于机器视觉的小阻力扣件状态监测方法,可见小阻力扣件在福厦高铁渔溪特大桥区段具有较好的纵向服役状态,且监测周期内线路状态...     

本地网光缆线路维护抢修经验浅谈

由于光缆线路的大量敷设和使用,不同用户对光资源容量、稳定性要求越来越高,本地网光缆线路日常维护越发显得重要。为了及时恢复光缆线路障碍引起的传输信号中断,必须采用结合光缆线路故障抢修经验最快速度查找光缆线路障碍点及对光纤断点进行接续。本地网光缆线路维护工作的主要内容、实际工作中对光缆线路障碍的查找方法、获得了光纤接续、光缆线路故障抢修经验等结论。     

大型三维混凝土结构温度场的光纤监测技术

以中国广西红水河乐滩水电站工程为背景、以光纤分布式温度测量系统为手段，研究了3号机组常态混凝土浇筑过程混凝土结构三维温度场的变化．首先，验证了光纤分布式温度测量系统成果的可靠性和准确性；其次，埋设不锈钢铠装传感光缆2km，共10个不同高程的层面，研究了常态混凝土水化热的释放过程、冷却水管的作用效果、温度随混凝土浇筑层厚度等的变化而变化的规律．     

自然循环静态流量漂移诱发动态流量振荡研究

为探讨两相流及流动稳定性理论及工程问题,通过实验研究描述了自然循环静态流量漂移及静态流量漂移过程中出现的动态流量振荡现象;研究了在自然循环系统中流量发生漂移时系统循环流量,加热段进出口温度的变化规律。结果表明欠热沸腾所引起的流动阻力变化是导致静态流量漂移的主要原因;在发生静态流量漂移时系统循环流量下降,进口温度下降及出口温度上升;随着静态流量漂移的发展,欠热沸腾逐渐强烈,伴随着静态流量漂移系统内同时发生具有密度波及喷泉不稳定特点的动态流量振荡。在对现象描述的基础上,阐述了静态及动态流量不稳定发生的机理。研究结果证明在自然循环中静态流量漂移将会诱发动态流量振荡。     

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.     

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.     

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.     

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.     

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.     

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.     

橡胶颗粒沥青混合料低温抗裂性试验研究

以AC-13级配为基础,将橡胶颗粒代替部分集料掺入混合料中,以低温弯曲试验为评价方法对不同橡胶颗粒掺量下沥青混合料的低温抗裂性进行研究,并引入应变能密度值对混合料的低温抗裂性进行综合评价.试验结果表明:橡胶颗粒沥青混合料试件的破坏微应变均超过2 300,满足冬寒区的技术指标;无论是否掺加橡胶颗粒,随着温度的下降,沥青混合料破坏时的最大弯拉强度增大,弯拉应变降低,劲度模量增大;弯曲应变能密度在胶粒掺量为1%左右时具有较大的弯曲应变能密度值,此时橡胶颗粒沥青混合料具有较好的低温抗裂性.     

A computer generator for randomly layered structures

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

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.