成都天府新区正公路下穿成花铁路大斜交框架空间结构分析

采用空间有限元分析方法，分析成都天府新区正公路下穿成花铁路大斜交框架的空间受力特性，并根据分析结果对结构提出了合理配筋的意见，期望对今后类似的斜交框架设计能起到一些参考作用。     

大净开度电动双开塞拉门在BFC6128GBEV6纯电动城市客车上的应用

介绍了塞拉门分类、结构及特点,重点阐述了大净开度电动双开塞拉门在BFC6128GBEV6纯电动城市客车上的应用。     

大客车除霜器安装使用方面的问题分析与探讨

简要介绍大客车用除霜器的结构、原理及用途，根据在安装使用中出现的一些问题进行分析和探讨。     

Understanding How Policy Actors Improvise and Collaborate in the Great Barrier Reef

Complex policy frameworks guide the management of the Great Barrier Reef (GBR) at multiple decision-making levels. Mounting pressure on its outstanding universal value suggests that further improvements in governance are required. There has been little examination of the role of policy actors in addressing complex governance challenges in large scale marine protected areas (LSMPAs) involving multi-layered governance conflicts across diverse contexts. Framed by street level bureaucracy, pragmatic planning theory, and lessons from MPA governance, this paper examines how policy actors improvised and collaborated to advance outcomes in the GBR LSMPA. We assessed practice-focused oral histories with experienced policy actors who negotiated agreements and achieved policy outcomes in the GBR between 1985 and 2016. These policy actors were skilled improvisers, alternating between roles as democratisers, mediators, and negotiators. They used collaboration and facilitative leadership to advance policy in the face of governance problems. This enabled them to adapt policy across multi-level decision systems, address power and information imbalances, and generally deal with conflict and uncertainty. A deeper understanding of improvisation will assist governments and others to address complex challenges in LSMPAs.     

被动柔性防护网结构足尺冲击试验研究

为研究被动柔性防护网结构的落石防护性能,设计2组防护能级为750 k J的柔性被动防护网结构,进行足尺冲击试验研究。模型1为按照现有标准所选型得到的系统配置;模型2为改进后的柔性被动防护网结构。试验结果表明:模型1无法拦截750 k J落石的冲击,系统崩溃;模型2成功地拦截了落石,且冲击后模型2的各主要组成构件等均未发生破坏,仅需要对耗能元件进行更换,即可继续投入使用。通过对高速视频的解构,对各部分组成构件的运动和受力特征进行详细分析,明确系统的三阶段工作历程,并分析系统失效的关键因素,同时,对实测的钢丝绳拉力时程进行对比分析。研究结果为今后柔性被动防护网结构的设计提供了理论基础。     

物流企业规模经济计量研究

目前对物流企业规模经济的研究还停留在定性分析阶段,为了定量对其进行分析,首先对规模经济的计量方法进行探讨,应用数理统计方法首次建立物流企业规模经济计量模型,最后应用该模型进行实例分析并得出物流企业中存在规模经济现象和它获取规模经济的具体方法的结论.该方法可为以后物流企业规模经济的进一步分析和研究提供一种新的思路和方法.     

城际铁路与地下道路共构设计大断面方案比选

为合理确定城际铁路与地下道路共构设计时隧道匝道汇入主体结构的大断面方案,采用有限元计算软件Midas Civil分别对平顶顶板、折板形顶板及拱形顶板3种方案进行建模计算,分别对不同方案的位移、应力、弯矩等进行分析。结果表明,拱形顶板与折板形顶板的受力性能均优于平顶顶板,且刚度增大,应力分布合理,弯矩值大幅度减少。综合考虑施工难易程度、工程量等因素,结论是选用折板形式作为隧道与城际铁路合建段大断面的顶板施工方案,具有结构受力合理、施工技术成熟、工程造价可控三大优势。     

可视化技术在港工结构稳定性研究中的应用

可视化技术能够以突出的细节画面再现实验或模拟的过程和结果,使研究人员观察到数据中的隐含现象,进而深入分析实验的结果。利用Dephi编程,以"沉入式大直径圆筒结构施工期稳定性实验研究"的数据和结论为例,应用可视化技术研究开发了可视化软件。该软件可以判断在施工期大圆筒是否满足稳定性的要求,可将数值模拟或物理实验的过程和结果在屏幕上动态地显示出来。     

大断面连拱隧道施工要点探讨

分析大断面连拱隧道的工程特点,总结其主要施工方法和注意事项,对今后公路隧道施工提供参考。     

On the hydroelastic responses of a very large floating structure in waves

New numerical methods are presented for hydroelastic analyses of a very large floating structure (VLFS) of several kilometers length and width. Several methods are presented that accelerate computation without an appreciable loss of accuracy. The accuracy and efficiency of the proposed methods are validated through comparisons with other numerical results as well as with existing experimental results. After confirming the effectiveness of the methods presented, various characteristics of the hydroelastic behavior of VLFSs are examined, using the proposed methods as numerical tools. Received for publication on Dec. 3, 1999; accepted on Dec. 15, 1999