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61.
针对水平受荷单桩变形内力的求解提出了一种新解法.根据基地反力系数三参数模型、线弹性地基上的Euler-Bernoulli梁理论和微段平衡条件,建立了以桩身响应表示的状态空间方程组.为了使状态空间方程线性化,将桩均匀化为若干小段,并且假定任一小段上地基反力系数为常数.利用所有桩小段的状态空间方程组、桩顶及桩底处的边界条件、桩段之间的变形内力连续条件和矩阵分析理论,获得了求解水平荷载单桩内力与变形的状态空间解.采用Matlab编制了计算程序,通过特例的解与已有半解析解进行对比来验证解的可靠性.最后,分析了桩底约束条件以及土体参数对桩身响应的影响.计算结果表明:状态空间法是一种易于程序编制、计算精度又易于控制的方法;当桩长较大时,桩底约束条件对桩身响应的影响很小;地基反力系数中的指数以及反映地表处土体抗侧向变形能力的参数对桩身响应的影响很大,不容忽视.  相似文献   
62.
宁波高等职业技术教育发展研究   总被引:1,自引:1,他引:1  
本文通过回顾宁波高等职业教育漫长而曲折的发展历史,分析了宁波高等职业教育实现新的腾飞的原因及其特点,对高等职业教育的发展、探索和研究具有一定的借鉴作用.  相似文献   
63.
Terrorist attacks occur mostly at public service-oriented sites. Consequently, their victims are likely to be customers. The present study explores how customers instinctively react toward the reality of terror in a matrix of 2 × 2 aspects concerning terror circumstances: temporal proximity (brief or long) and physical proximity (close or remote) from the terror event. In qualitative in-depth interviews, customers from France and Israel were requested to share their instinctive reactions and coping strategies when approaching hospitality (hedonistic) and transportation (utilitarian) services. Participants (N = 47) comprised customers having a protracted acquaintance with persistent terror threats. The analysis identified differences in reactions, subject to temporal and physical proximities. When terror attacks are physically close, customers’ emotions, cognitions, and behaviors undergo modification with time. However, when terror attacks occur at a location remote from the customer, customers’ emotions and cognitions, but not their behavior, change with time. These reactions were comparable for the two service contexts. Practical implications were elaborated to enable service establishments (i.e., hospitality and transportation) to design and manage their operations for the short and long term to assist customers in the difficult era of terror.  相似文献   
64.
In event studies, the now standard window of a few days may miss relevant price movements if the market’s reaction to the news announcement tends to be slow or if the initial reaction tends to be partially or wholly undone afterwards. We propose a parsimonious hybrid of splines and Almon lags to detect and classify various patterns of post-event reactions spread over many periods. The scheme can interact with one or more event characteristics (like deal size), and the resulting non-linear model can be estimated via maximum likelihood (ML).In our application, we study the returns pattern that follows takeover announcements by two leading serial acquirers, AB Inbev SA and Heineken. Our method confirms the presence of a drop-and-recovery pattern as reported in Doan and Sercu (2021), but the amplitude of the pattern shows no link with deal size. This last finding is not in line with the view that the pattern reflects a rise in uncertainty that is slowly resolved (Malatesta and Thomson, 1985).  相似文献   
65.
This paper explores economic, political and institutional determinants of discretionary fiscal policy in 11 Central and Eastern European (CEE) countries from 2000 to 2013 and compares discretionary fiscal reactions before and during the global economic crisis. We find that fiscal policy was procyclical to the output gap both before and during the crisis, while no fiscal reaction to the absorption gap was captured. Our results also indicate a negative relationship between the level of public debt and deficits over the entire period and the pre-crisis period, suggesting that rising public debt represented a brake on future deficits. We also find that election cycles affect the fiscal deficit, but only during the pre-crisis period, while no evidence of a relationship between fiscal policy and government fragmentation was captured. We find some evidence that in the pre-crisis period the CEE countries with a fixed exchange rate regime ran lower deficits than those with a floating regime, whereas during the crisis no impact of the exchange rate regime on the fiscal deficit was found. There is also some evidence that an arrangement with the IMF was associated with lower deficits for the entire sample period. However, no impact of EU accession on the fiscal stance was identified.  相似文献   
66.
Building on social movement theory, this study assesses the influence of social media activism on the stock market performance of targeted firms. We focus on information published on Twitter by two critical stakeholders: consumer associations and trade unions. To the extent that social media represent a valid medium to mobilize stakeholders' activism, protests on Twitter may damage firm reputation, leading to capital market reactions. Using a corpus of over 1.5 million tweets referring to Spanish listed banks, we study the impact of activism by looking at targeted firms' abnormal variations in price and trading volume. Our findings suggest that the Twitter activism of key stakeholders has a significant impact on investors' decisions. Further, our empirical analyses indicate that the mechanisms affecting investors' behavior differ depending on the characteristics of the stakeholder group. Hence, this study contributes to understanding how social movements influence corporate behavior via social media. Copyright © 2017 John Wiley & Sons, Ltd and ERP Environment  相似文献   
67.
廖漓文 《价值工程》2015,(13):69-70
萤石的经典分析方法是将碳酸钙和氟化钙分离后,在用滴定法分别进行滴定分析,这种分析方法较为准确,但周期长、效率差、多次滴定易产生误差,无法满足快速大量测定样品的要求。本文探讨通过采用滴定-原子吸收法相结合方式测定萤石中氟化钙、碳酸钙的含量,可在大幅缩短测定时间的同时避免二次滴定产生的误差提升结果准确度,并可用于满足大量萤石样品的分析需求。  相似文献   
68.
The present rapid urban growth of cities from developing countries causes negative externalities such as lagging infrastructure development. In combination with rapidly rising motorized vehicle use this leads to severe traffic congestion affecting the mobility of the urban residents. Therefore many urban governments are planning to improve their transport and mobility situations with mass rapid transit systems of which a bus rapid transit (BRT) is a rather easy system to implement at reasonable costs. However, due to high urban inequalities the effects of urban traffic and potential improvements of the urban transport system for the diverse group of urban residents can differ significantly. In our case study Kampala (Uganda) four main groups were identified through cluster analysis of socio-economic and residential data gathered through interviews: extreme poor, poor, middle income and rich. Each group experiences a different mobility with the extreme poor being the most vulnerable group. The planned BRT system aims to decrease the average travel time but risks to exclude the lowest income class since not enough attention is paid to the affordability of the system to all residents. Therefore we argue for a policy that works from bottom up and pays attention to the internal diversity of the population.  相似文献   
69.
海峡西岸快速城市化中土地利用变化的影响因素   总被引:4,自引:0,他引:4  
利用2003—2007年海西的遥感和统计资料,根据海西的城市化发展和土地利用动态变化,选取12个影响海西土地利用变化的因子,构建影响土地利用变化的指标体系,并进行相关性分析和多元逐步回归分析,得出影响因子的最优多元线性回归方程。从定性与定量相结合的角度探讨海西土地利用变化的驱动因素。研究表明:①在影响指标体系的相关性分析中,所选取的指标基本上都与海西土地利用变化具有显著的相关性,特别是人口增长、经济发展、产业结构变化及城市化水平等因子。②在多元回归分析中,城市化水平、第一产业占GDP的比重、进出口总额、非农业人口比重、总人口等因素成为了各类土地利用类型变更的重要影响因素。③人口、城市化水平、产业结构等因素是影响土地利用变化的最主要因素。在未来海西城市的发展过程中,应该调整好城市发展中的各因素与土地利用的关系,促进土地的合理利用。  相似文献   
70.
《国家突发公共事件总体应急预案》充分反映了当代公共行政的价值取向,体现了政府应对突发公共事件的新理念;认真研究和把握这些精神和理念,有利于我们积极、主动应对和处置各类突发公共事件,实现处置突发公共事件的人本化、法治化和科学化。  相似文献   
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