PPS导向系统在TBM中的应用

TBM的PPS定位、导向系统,可为TBM确切位置和掘进方向定位,为操作手提供TBM偏离轴线的信息。根据PPS系统的定位原理,掌握PPS在TBM中应用的程序,了解TBM在掘进过程中的偏差因素,采取对其纠偏的措施,可保证TBM严格按设计坐标方位掘进。     

隧洞灌浆效果声波检测数据综合统计方法探索

高压固结灌浆是隧洞施工处理的常规手段,其质量直接影响隧洞运行安全,因此对施工质量进行检测以便排除隐患十分重要。近十年来,多种方法的综合声波测试已成为灌浆效果检测的有效手段之一,但对多种方法检测结果分别评判是否达到设计标准难下定论。为此,通过对大量声波、弹模数据和工程运行情况进行对比、统计和分析,总结出了一种针对隧洞高压固结灌浆效果的多种声波检测综合数据统计方法,并已用于多个水电项目中。     

无线数据传输技术在石油行业中的应用及展望

概括总结了在石油行业中使用的无线数据传输技术,主要可分为常规无线数据传输和井下无线随钻传输。提出了两点展望:利用短距离无线采集与远程无线数传相结合,可实现钻采现场参数实时监测;研发声波无线数据传输新型钻杆接头,能克服能量衰减问题,提高声波传输距离。     

灰岩单轴压缩过程中干燥与饱水状态对声发射特征的影响

为探究水岩耦合条件下的声发射规律,通过开展干燥与饱水灰岩单轴压缩条件下的声发射监测试验,并结合快速傅里叶变换、短时傅里叶变换与离散小波变换这3种常用的声发射信号分析方法,对比分析了干燥与饱水灰岩的时域参数、频率特征与典型破裂信号的时频特征。结果表明:水对于岩石的变形破坏特征影响显著,相对于干燥状态,饱水试样的单轴抗压强度下降明显,且幅值、能量以及振铃计数等基本时域特征参数均呈现出大幅降低的特点;岩样破坏前,干燥与饱水灰岩都表现出由“高主频、低幅值”向“低主频、高幅值”过渡的总体变化趋势;干燥岩样破坏前主频值高于饱水岩样,完全破坏后却低于饱水岩样,主频下降幅度大,而饱水岩样的主频值波动较小,频率较为稳定。研究结果对于工程尺度的防突机构声发射监测具有一定的参考价值。     

浅谈GPS实时动态技术在土地测量中的应用

GPS实时动态测量技术相比各种传统的测量技术和方法,有其独特的优点。本文通过介绍GPS实时动态技术的构造以及测量原理,分析了GPS实时动态技术在土地测量工作中的优势,并给出了GPS实时动态技术在实际测量工作中的应用方法。     

MECHANISM OF SOUND GENERATION BY FLOW OVER TWO CAVITIES IN TWO DIMENSIONS

1 .　ＩＮＴＲＯＤＵＣＴＩＯＮＷｈｅｎｈｉｇｈ ｓｐｅｅｄａｉｒｆｌｏｗｏｒｃｕｒｒｅｎｔｐａｓｓｅｓｏｖｅｒｇａｐｓｏｒｃａｖｉｔｉｅｓｉｎａｆｌａｔｐｌａｔｅ ,ｓｅｌｆ ｅｘｃｉｔｅｄｏｓｃｉｌｌａｔｉｏｎｓｍａｙｏｃｃｕｒ ,ｌｅａｄｉｎｇｔｏｄｒａｍａｔｉｃｐｒｅｓｓｕｒｅａｎｄｖｅｌｏｃｉｔｙｆｌｕｃｔｕａｔｉｏｎａｎｄｉｎｔｅｎｓｉｖｅｎｏｉｓｅ .Ｔｈｅｓｅｐｈｅｎｏｍｅｎａｍａｙａｐｐｅａｒｉｎｍａｎｙｅｎｇｉｎｅｅｒｉｎｇａｐｐｌｉｃａｔｉｏｎｓ .Ｆｏｒｅｘａｍｐｌｅ ,ｗｅａｐｏｎｂ…     

油田社区服务“三精”质量控制模式的实践与思考

介绍了油田社区服务单位的现状与特点,联系实际论述了精准定位、精确作业、精细管理质量控制模式的概念与架构,探讨了该模式运行的关键控制点、控制措施及其推行该模式产生的效果。     

Bridge,Focus, Attack,or Stimulate: Retail Category Management Strategies with a Store Brand

We investigate a monopolist retailer's category management strategy where the main strategic decisions are how to horizontally position a store brand relative to the incumbent national brands and how to price the store and national brands for retail category profit maximization. We analyze a market composed of two consumer segments with differing tastes and heterogeneity with respect to willingness to pay and a product category consisting of two competing national brands and one store brand. We find that contrary to the existing literature, it is not always optimal for a retailer to position its store brand against the leading national brand; instead there are many situations where it is best to position the store brand close to the weaker national brand or to position it in the “middle” so it appeals to both national brands' target segments. In the process we identify four distinct category management strategies that a retailer can use with a store brand. In three of these the optimal store brand price is the brand's monopoly price, while in the remaining one strategy the price is lower. We also suggest an easy to implement means for a retailer to determine which strategy is best to use, depending on the particular competitive environment present before the introduction of the store brand and the relative quality of the store brand. We find that the store brand entry is most beneficial to the retailer when the national brands are moderately differentiated. Finally we show that introducing a store brand not only allows the retailer to garner a higher share of the channel profits through higher retail margins, but also often provides the retailer the benefit of increases in national brand unit sales as well as incremental sales from the store brand. JEL Classification: M310     

简析小教大专中文专业写作教学定位

探讨小教大专写作教学，根据小教大专的特点定位：正确选择教材，合理选用教法，明确培养目标。深化教学改革，圆满完成小教大专的写作教学任务。     

GPS与GIS集成定位在铁路列车上的应用

针对GPS(全球卫星定位系统)单独定位系统存在的缺陷,对GPS与地理空间信息系统GIS相结合的铁路列车定位的工作原理、铁路GIS地图数据库的建立、GPS与GIS间的接口、GPS坐标与数字地图强制匹配的算法及GIS距离推算等问题做了初步阐述。