三峡水库蓄水诱发神女溪岸坡破坏机制研究

在相关文献研究的基础上,列举出诱发巫山神女溪滑坡的因素,从而分析巫山神女溪由于三峡水库蓄水前后,水位变动诱发库岸滑坡的机理,研究其破坏形成机制是防治库岸滑坡的核心.简述在库水位变化情况下,岸坡库水间相互作用及其岸坡稳定性分析的计算方法.     

岸线变化对天津近岸海域污染物输移扩散影响研究

应用MIKE21数学模型对天津近岸海域潮流场进行数值模拟,同时考虑天津近岸海域5个典型河口污染物输入的影响,计算了大小潮作用下COD输移扩散范嗣,并研究了岸线变化对COD输移扩散范围的影响.结果表明,岸线的变化对北塘口及天津港附近COD的输移扩散有较大影响.岸线变化后,大小潮高低潮时刻对应的0.001 mg/L浓度等值...     

自动调温阀拆除对柴油机危害的分析

文章叙述了柴油机冷却水自动调温阀的工作原理和调温特性,分析了调温阀拆除后冷却水温的变化及对柴油机性能的影响,并就维修中燃烧室组件的大量更换是否与调温阀的拆除有关进行了探讨。     

Insights on disruptions as opportunities for transport policy change

Policy change is characterised as being slow and incremental over long time periods. In discussing a radical shift to a low carbon economy, many researchers identify a need for a more significant and rapid change to transport policy and travel patterns. However, it is not clear what is meant by rapid policy change and what conditions might be needed to support its delivery.Our contention in this paper is that notions of habit and stability dominate thinking about transport trends and the policy responses to them. We limit variability in our data collection and seek to design policies and transport systems that broadly support the continuation of existing practices. This framing of the policy context limits the scale of change deemed plausible and the scope of activities and actions that could be used to effect it.This paper identifies evidence from two sources to support the contention that more radical policy change is possible. First, there is a substantial and on-going churn in household travel behaviour which, harnessed properly over the medium term, could provide the raw material for steering behaviour change. Secondly, there is a growing evidence base analysing significant events at local, regional and national level which highlight how travellers can adapt to major change to network conditions, service availability and social norms. Taken together, we contend that the population is far more adaptable to major change than the policy process currently assumes.Disruptions and the responses to them provide a window on the range of adaptations that are possible (and, given that we can actually observe people carrying them out, could be more widely acceptable) given the current configuration of the transport system. In other words, if we conceptualise the system as one in which disruptions are commonplace, then different policy choices become tractable. Policy change itself can also be seen as a positive disruption, which could open up a raft of new opportunities to align policy implementation with the capacity for change. However, when set against the current framing of stability and habit, disruption can also be a major political embarrassment. We conclude that rather than being inherently problematic, disruption are in fact an opportunity through which to construct a different approach to transport policy that might enable rather than frustrate significant, low carbon change.     

单线隧道24 m仰拱栈桥施工技术研究

为了加快单线隧道施工进度,并确定24 m自行式液压栈桥施工流程和工艺,通过对24 m栈桥仰拱施工一次性浇筑、一次性浇筑24 m并加防裂网片、分区段12 m同步施工,3种施工方案进行分析,发现一次性浇筑及增加防裂筋施工工艺会出现仰拱断面开裂,分区段12 m同步浇筑既保证仰拱断面无裂纹,也加快了施工进度。文中同时提出多工作面施工理念,合理加快施工进度;通过微创微改在配套的矮边墙模板上焊接定位卡、堵头板采用钢木混合安装,反坡排水;安装移动水箱和预留水沟槽等工艺。     

Phase change analysis of an underwater glider propelled by the ocean＇s thermal energy

The phase change characteristic of the power source of an underwater glider propelled by the ocean＇s thermal energy is the key factor in glider attitude control. A numerical model has been established based on the enthalpy method to analyze the phase change heat transfer process under convective boundary conditions. Phase change is not an isothermal process, but one that occurs at a range of temperature. The total melting time of the material is very sensitive to the surrounding temperature. When the temperature of the surroundings decreases 8 degrees, the total melting time increases 1.8 times. But variations in surrounding temperature have little effect on the initial temperature of phase change, and the slope of the temperature time history curve remains the same. However, the temperature at which phase change is completed decreases significantly. Our research shows that the phase change process is also affected by container size, boundary conditions, and the power source＇s cross sectional area. Materials stored in 3 cylindrical containers with a diameter of 38ram needed the shortest phase change time. Our conclusions should be helpful in effective design of underwater glider power systems.     

东平水道水文动力条件的变化

本文根据东平水道沿程水文(位)站多年水文资料的分析,研究了东平水道上世纪60年代以来水文动力条件的变化。研究表明,东平水道在上世纪90年代以前,水文动力条件变化不大,但在这之后,发生了较大的变化,主要表现在:流量加大、水位降低、含沙量略有减小,悬移质输沙量增大、潮汐作用增强。     

细看2004年水上危险货物运输管理要求的变化及对策

2004年1月1日,《港口法》、《港口危险货物管理规定》和《船舶载运危险货物安全监督管理规定》同时生效,调整了水上危险货物运输的管理,本文试就这些变化和对策做了一些探讨,供同行们参考。     

从武广电化项目后评价分析投资变化的原因

积极开展铁路建设项目后评价，及时收集整理已经完成项目的各阶段概预算资料和技术总结．分析引起投资演变的主要原因，是保证后续铁路建设项目正确决策和控制投资的必要手段。此文通过分析武广铁路电气化投资的演变过程，探讨和分析引起投资波动与变化的主要原因，认识和掌握投资变化的基本规律。     

密立根油滴实验中平衡电压和下落时间关系的研究

通过分析平衡电压和下落时间的隐函数关系表达式,推导出了两者之间的直接函数表达式和变化关系。同时用数值模拟和实验验证的方法,得到这样的结论：随着下落时间的逐渐增长,平衡电压是逐渐变小的,而且变化率是越来越小。实验过程中油滴质量的减小很好地解释了两者之间的变化关系。剔除掉由于电量减小造成的不合理数据可以提高实验的准确度。