桥梁挂篮悬浇施工技术

作为当前桥梁施工中的关键施工设备,挂篮开始成为建设队伍的关注重点。本文探讨了桥梁工程项目中挂篮施工技术。     

谐振式悬架装置检测控制系统研究

在对谐振式悬架装置检测系统的基本结构、检测原理和系统构成进行阐述的基础上,介绍了悬架试验台的控制系统的信号采集方法,以及对信号处理和分析的过程。在软件控制系统中,使用了峰值包络线找极值的方法,剔除了干扰点对系统构成的影响,减小了测量的误差,确保了测试的重复性和数据的可靠性、准确性。     

云南龙江大桥锚碇选型研究

悬索桥以其构造简单、受力明确、跨越能力大、造型美观等优势,在我国高速公路建设中得到了广泛应用。锚碇作为悬索桥的基础,对整座桥梁的安全有着重要的作用。本文针对云南龙江大桥的地形以及全风化岩层的地质情况,选择适合的锚碇型式,进行结构分析和方案比选,确定最优的锚碇方案,以期给类似地形地质条件下的悬索桥锚碇设计提供参考。     

悬索桥施工综述

以悬索桥工程为例,详细介绍悬索桥的施工工艺,并对施工难点问题进行分析、探讨。     

Stock market restrictions and corporate social responsibility: Evidence from IPO suspension in China

Improving corporate social responsibility (CSR) requires not only the efforts of firms themselves but also the support of the appropriate institutional environment. This paper assesses whether access to the stock market can promote firms’ CSR. Using China’s suspension of IPOs in 2012–2014, we find that firms affected by the suspension show lower CSR in their listing year. The later listing after the suspension ends, the greater reduction in CSR. Moreover, the effect of the IPO suspension is more serious for firms with financial constraints than for non-financially constrained firms. Furthermore, we show that the IPO suspension has an adverse impact on firms’ liquidity and profitability. When this suspension ends, firms’ CSR activities recover within 1–2 years. Overall, our conclusion enriches the literature on the factors influencing CSR and provides firm-level evidence of the adverse impact of an IPO suspension.     

Why Can't I Trade? Exchange Discretion in Calling Halts*,†

Stock exchanges are important intermediaries in how firm information enters price. Trading halts are a key tool, often exercised at the exchanges' discretion, to prevent extraordinary price volatility when new information arrives. We investigate how exchanges use discretion and whether the discretion alters the effectiveness of the halts. We provide evidence consistent with halts reflecting the preferences of listed firms rather than the stated exchange objectives (i.e., minimizing excess volatility and off-equilibrium trades). Furthermore, when exchanges exercise more discretion (unexplained by firm and information characteristics), the halts are less effective. Specifically, halts with more discretion are less likely to resume trading with efficient prices and are more likely to have been called unnecessarily (i.e., little to no price movement during the halt). These findings are consistent with exchanges using halts to cater to listed firms rather than to meet exchange objectives such as minimizing excess volatility or avoiding trades at off-equilibrium prices.