用新观点研究预测中国2010—2011年车市发展

为分析研究2011年及近期车市发展趋势,供汽车产销单位经营决策参考,采用"车市波动分析法",用车市季度主要参数表和年度车市波动图分析车市实际走势。肯定了汽车产销量超美的成绩。指出2010年车市逐季度大幅回落趋势,分析了罕见的"波形异常"问题的影响及原因。对2011年面临形势进行了分析和预测:车市处于扩张后期,中下等市场,2011年后车市仍有可能小幅回升,对"十二五"期间车市发展持审慎乐观态度。     

SS6B型电力机车牵引电动机环火原因及防止措施

对SS6B型电力机车ZD114型脉流牵引电动机第一次中修后运用时所发生环火故障进行分析,并且探讨在设计、制造、运用及检修方面是否存在不同程度的缺陷。根据实际运用及检修经验,在此提出一些防止措施,已经取得一些初步效果。     

复杂城市场地下大跨度桥梁总体设计关键技术研究

以常德沅江六桥总体设计为例，分析了基于复杂城市场地下大跨度桥梁设计特点及需考虑的各方面因素，阐述沅江六桥方案的设计思路。综合考虑规划路网、沿线高压电走廊、沅江水文条件、地震断裂带等因素，对大桥的规划桥位进行优化调整，提出推荐桥位方案。根据通航要求和规划码头等条件，确定推荐方案的桥梁跨径和桥型。简要介绍桥梁结构设计，并验证主要结构的科学合理性。     

Mechanical model and characteristics of deep-water drilling riser-wellhead system under internal solitary waves

Internal solitary waves with a huge amount of energy easily trigger the large dynamic responses of riser-wellhead system and threaten its structural safety. However, previous studies have only focused on the dynamic response of the riser under internal solitary waves. The riser may experience excessive traction from the platform, especially from the mooring platform, in response to the arrival of internal solitary waves. The bottom of the riser connects to the wellhead system, which in turn exerts a reaction force on the riser. To address this problem, a coupled dynamic model of deep-water drilling mooring platform-riser-wellhead system under internal solitary waves is developed in this paper. A dynamic response analysis method based on the fourth-order Runge-Kutta method and finite element method is also proposed for the mooring platform-riser-wellhead system. A dynamical solver for the coupled system is then developed using MATLAB. The dynamic response characteristics of the riser-wellhead system under internal solitary waves are calculated. Results show that the displacement and bending moment of the system initially increases and then decreases along with the propagation of internal solitary waves, and finally reach equilibrium position. The displacement and bending moment reach their peak before the trough of internal solitary waves passes through the riser-wellhead system. The dynamic responses of the riser-wellhead system under the influence of internal solitary wave loads are much larger than those without the effect of internal solitary wave loads. The riser system experiences shearing loads at the interface of internal solitary waves, which trigger a step-like bending moment variation. The bending moment of the conductor under the mudline is greatly increased by the internal solitary waves.