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1.
现代桥梁工程中高墩桥梁屡见不鲜,桥墩垂直度已成为评定桥墩施工质量的重要指标之一.以新疆某特大桥项目为依托,针对高墩垂直度检测结果实用性低的问题,提出一种采用三维激光扫描技术对高墩垂直度进行非接触测量分析的方法.利用三维激光扫描仪快速获取高墩结构全局点云信息,对桥墩点云进行拼接、降噪等预处理,采用编程算法实现了桥墩节段中心点和垂直度偏差的计算,并得到了垂直度偏差变化规律图.最后将该方法与传统方法进行对比.结果表明:利用三维激光扫描技术对高墩进行快速测量,能够获取桥墩中心轴线的三维空间线型,精确分析并定位最大偏差位置,显著提高垂直度测量结果的实用性,具有良好的工程应用前景,并为后续研究桥墩垂直度问题提供了新思路. 相似文献
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The propensity of the forecasts of sell-side financial analysts to converge (or diverge) is a function of their exogenous and endogenous selective attention and overconfidence. When returns are negative, the endogenous form of selective attention—a static measure of analysts’ goal-driven attention at a particular point in time—has a positive association with convergence. The exogenous form of selective attention—a relatively involuntary dynamic process of exogenous attentional shift driven by external changes in the market over time—is associated with a tendency for forecasts to diverge. 相似文献
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We investigate the impact of Form 8-K filings on cross-firm differences in analysts’ private or idiosyncratic information in the post-Reg FD era. Using firms’ connections to the investment community to identify the likelihood of selective disclosure, we document differences in analysts’ idiosyncratic information arising from selective disclosure before 8-K filings. While filings of 8-Ks pursuant to Reg FD attenuate the link between connections and analysts’ idiosyncratic information, they do so only after selective disclosures have already resulted in some analysts having better private information. In addition, the connections continue to facilitate private information search after the filings of non-Reg FD-specific 8-Ks. 相似文献
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提出了联合测量超短激光脉冲混合啁啾量值的方法,这种方法是基于干涉自相关包络宽度及超短激光脉冲光谱宽度随啁啾量值的变化而变化.通过对干涉自相关信号包络宽度及超短激光脉冲光谱宽度的理论分析,得到干涉自相关包络宽度及超短激光脉冲光谱宽度与啁啾量值之间的对应关系,获得联合测量混合啁啾量值的方法.采用干涉自相关二次谐波检测系统对加浓染料激光器输出的脉冲进行测量,利用该方法测量出被测超短激光脉冲的线性啁啾值及平方啁啾值.根据干涉自相关包络信号及超短激光脉冲光谱,分别独立测量超短激光脉冲混合啁啾值,从而实现了对超短激光脉冲啁啾值的确定性测量. 相似文献
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Jung Eun Lee 《心理学和销售学》2019,36(1):57-71
Retailers frequently use exaggerated price discount advertisements with a tensile price claim (TPC; e.g., “Save up to 70%”) to attract consumers because they expect that once consumers enter a store, they will purchase low‐ or medium‐discounted products. Drawing on the selective accessibility model, this study investigated the way in which an implausibly high maximum level of savings stated in a TPC influences consumers’ expected price discount (EPD) and perceptions of actual price discounts across different types of TPCs (i.e., TPC stating a maximum level and TPC stating a range of savings). This study also investigated two situations in which consumers have previous knowledge of a product’s price discount versus when they have less or no knowledge of the discount. For both conditions, a single‐anchor TPC (i.e., “Save up to Y%”) that stated an implausible maximum level of savings led to a higher EPD and lower perceptions of the deal (i.e., perceived savings, price fairness, and perceived value) with respect to the actual price discount than did a TPC with a plausible maximum level of savings. In contrast, when the TPC stated two anchors (i.e., “Save X–Y%”) and consumers had knowledge of the price discount, their EPDs assimilated only toward the plausible anchor (X), and ignored the implausibly high maximum price discount (Y), resulting in a lower EPD and higher perceptions of the deal of the actual price discounts than a TPC that stated a plausibly high maximum level of savings. In contrast, when consumers had no knowledge of the price discount, their EPDs only adjusted toward the more plausible anchor (X), regardless of whether they perceived the maximum anchor as plausible or implausible. Thus, there was no difference in consumers’ perceptions of “Save X–Y%” between implausibly and plausibly high Y%. 相似文献
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本文阐述了激光加工技术专业人才培养方案建设主要包括方案设计的基本原则、人才的培养目标与人才规格、工作任务与职业能力分析、课程体系的构建,对于培养合格的激光加工技术专业技能型人才具有重要意义。 相似文献
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文章简述了无胶斑激光靶的制备工艺。原先的平面靶是将靶杆直接放到金圆盘靶平面上用胶粘接,现在是金圆盘本身长出连接金丝,使金丝与靶杆用胶粘接,从而避免了金圆盘表层有胶。在电火花加工过程中,工具和工件之间的脉冲火花放电产生局部,瞬间的高温把金属材料逐步蚀除掉,因此工具与工件之间无相互作用力。在微细加工方面有独特的优势。重要的是一次加工成型,既保证了加工精度,又提高了加工效率,省时省力。无胶斑激光靶的研制成功,消除了激光靶表面上的胶斑,同时也提高了激光靶的装配质量,使激光靶的制造精度得以提高,为物理实验提供了条件。 相似文献