交错钢桁架体系的腹杆布置及其截面形式研究

混合桁架是钢结构交错桁架体系常用的桁架形式，用于工程实践时，应采用适宜的腹杆布置形式及经济合理的截面形式。本文主要研究了以下几个方面的问题：因建筑需要而设置的空腹节间处于桁架内不同位置时，桁架杆件在竖向荷载作用下的内力变化；常用对称式混合桁架的腹杆布置形式对桁架内力及总用钢量的影响；桁架腹杆采用T型钢、矩形钢管、圆钢管、角钢时桁架的总用钢量比较。比较结果表明：空腹节间不应设置在桁架端部；常用混合桁架腹杆采用“之”形布置时用钢量最省；桁架腹杆选用T型钢和角钢较为经济合理。     

框架锚索结构计算初探

简要介绍了框架锚索(杆)中框架内力的两种基本计算方法,并结合工程实例,详细说明了两种方法的设计过程及适用条件。     

蒸压纤维水泥板覆面轻钢龙骨式复合墙体抗剪性能试验研究

为研究采用蒸压无石棉纤维素纤维水泥板(CCA板)覆面的轻钢龙骨式复合墙体的抗剪性能,进行了13片足尺墙体的水平单调加载和低周反复加载试验。试验结果表明,采用CCA板覆面轻钢龙骨式复合墙体的破坏主要表现为自攻螺钉连接处的CCA板拉裂或者螺钉拔出,最终CCA板失去传递剪力的能力而破坏,轻钢龙骨未发生明显破坏。基于试验结果,得到了各类CCA板覆面墙体的屈服荷载、最大荷载、破坏荷载以及位移延性系数等性能指标。最后,分析了CCA板厚度、密度以及加载方式对轻钢龙骨式复合墙体受剪性能的影响,并与OSB板、石膏板覆面墙体进行了比较。     

Framing processes in planning disputes: analysing dynamics of contention in a housing project in Hong Kong

Opposition to planned housing projects can lead to considerable delays. Hong Kong is characterized by an executive-dominant planning system, whereby the government possesses strong planning powers, while elected district councillors play an advisory role only. Curiously, planning delays are fairly common. The above paradox is analysed in this paper through examining a major dispute over public housing development in Hong Kong. This dispute involved lengthy processes of bargaining, which were vulnerable to legitimacy challenges. Councillors acted strategically by tapping into prevailing social values to frame the legitimacy of bargaining processes. Despite discontent with these informal bargaining processes, the dispute has not evolved into more radical challenges to existing governance arrangements. The paper concludes by considering how hegemonic discourses of planning efficiency may have constrained the emergence of radical contention, which adds to broader debates about the conditions which shape the trajectories and transformative prospects of contentious urban developments.     

Individual differences in drivers’ cognitive processing of road safety messages

Using Gray and McNaughton's (2000) revised reinforcement sensitivity theory (r-RST), we examined the influence of personality on processing of words presented in gain-framed and loss-framed anti-speeding messages and how the processing biases associated with personality influenced message acceptance. The r-RST predicts that the nervous system regulates personality and that behaviour is dependent upon the activation of the behavioural activation system (BAS), activated by reward cues and the fight-flight-freeze system (FFFS), activated by punishment cues. According to r-RST, individuals differ in the sensitivities of their BAS and FFFS (i.e., weak to strong), which in turn leads to stable patterns of behaviour in the presence of rewards and punishments, respectively. It was hypothesised that individual differences in personality (i.e., strength of the BAS and the FFFS) would influence the degree of both message processing (as measured by reaction time to previously viewed message words) and message acceptance (measured three ways by perceived message effectiveness, behavioural intentions, and attitudes). Specifically, it was anticipated that, individuals with a stronger BAS would process the words presented in the gain-frame messages faster than those with a weaker BAS and individuals with a stronger FFFS would process the words presented in the loss-frame messages faster than those with a weaker FFFS. Further, it was expected that greater processing (faster reaction times) would be associated with greater acceptance for that message. Driver licence holding students (N = 108) were recruited to view one of four anti-speeding messages (i.e., social gain-frame, social loss-frame, physical gain-frame, and physical loss-frame). A computerised lexical decision task assessed participants’ subsequent reaction times to message words, as an indicator of the extent of processing of the previously viewed message. Self-report measures assessed personality and the three message acceptance measures. As predicted, the degree of initial processing of the content of the social gain-framed message mediated the relationship between the reward sensitive trait and message effectiveness. Initial processing of the physical loss-framed message partially mediated the relationship between the punishment sensitive trait and both message effectiveness and behavioural intention ratings. These results show that reward sensitivity and punishment sensitivity traits influence cognitive processing of gain-framed and loss-framed message content, respectively, and subsequently, message effectiveness and behavioural intention ratings. Specifically, a range of road safety messages (i.e., gain-frame and loss-frame messages) could be designed which align with the processing biases associated with personality and which would target those individuals who are sensitive to rewards and those who are sensitive to punishments.