市政道路施工中新材料的应用探讨

文章在分析市政道路潜在安全隐患的基础上,进一步对新材料应用于市政道路施工的重要价值作用进行了分析,最后探究了几大新材料在市政道路施工中的具体应用,希望以此为市政道路施工质量的提升提供具有价值的参考凭据。     

基于工况分布的轻型车速度排放修正因子的建立方法

速度排放修正因子(Speed Correction Factors,SCF)是评估速度变化对车辆排放影响的重要参数.然而,传统的SCF建立方法耗时长、成本较高,且获取的SCF分辨率较低.为了得到高分辨率的SCF,基于北京市大量的实测工况数据和排放率数据,提出了北京市轻型车SCF的建立方法.首先,对采集的工况数据进行60 s短行程划分及2 km/h行程速度的聚类;在此基础上,建立不同道路类型和速度区间下的比功率分布(Vehicle Specific Power,VSP);然后,结合排放率和建立的VSP分布,建立不同道路类型、排放标准的各污染物的SCF.经过分析,得出相比传统的SCF建立方法,本文提出的方法更能反映车辆的实际行驶特征、且获得的SCF的速度分辨率更高.     

等体积比水雾对冲击波衰减规律研究

为分析水雾对爆炸冲击波的耗散与衰减作用,通过有限元分析方法,在单层网格内建立冲击波作用于同体积比不同尺寸分布的液滴模型,对液滴阻碍冲击波作用的规律进行分析总结,得到结论如下:液滴的存在对冲击波有一定的削弱作用,且在液滴总体积比相同条件下,液滴数目多的工况比冲量衰减更大,可知分散的小液滴对冲击波的衰减作用强于集中的大液滴.0.1 kgTNT在0.2 m爆距产生的冲击波在二维模型中,液滴体积比为2.21×10–3时液滴直径为0.866 mm时冲击波衰减2.06%,液滴直径为0.500 mm时冲击波衰减3.14%,液滴直径为0.354 mm时衰减3.39%.     

两部定价法在收费公路中的模型研究

收费公路是准公共产品,其收费定价脱离不了公共经济学的定价范畴。从公共经济学的角度,论述两部定价法在收费公路中的优势,明确成本归属,建立了两部定价模型。该模型具有操作性强、公平合理的特点,且能够有效抑制车辆超载、超重现象,体现了合理收费费率的三大原则。     

舰船装饰材料的发展及应用

介绍了我国舰船装饰材料的发展过程,以及舰船装饰材料在舰船上的应用要求,如耐火性、无毒性、耐腐蚀性、耐用性、装饰性、工艺性、可维修性等,还必须满足重量轻、强度高的要求。文章还就如何选用舰船装饰材料提出了几点建议。     

Group attitude and hybrid sanctions: Micro-econometric evidence from traffic law

In many legal domains hybrid sanctions – i.e. the joint use of both monetary and non-monetary sanctions – are usually applied. We suggest that one possible rationale behind this form of sanction is targeting group-specific deterrence. For some groups of agents, hybrid sanctions act indeed as a self-selection mechanism such that deterrence is obtained only after a critical threshold of infractions is reached. We apply our model to traffic law infractions and further test it, performing a micro-econometric analysis on a unique dataset of a representative sample of 50,000 Italian drivers, over six years (2003–2009), after the introduction of a penalty points system. Our findings empirically confirm our theoretical predictions. When repeated infractions are at stake, well-designed hybrid sanctions, such as the penalty point system designed for traffic law enforcement, may indeed increase overall deterrence. Our results shed new light on the role of the combined monetary and non-monetary sanctions to perform general and specific deterrence.     

Numerical simulation of violent sloshing by a CIP-based method

In this article, a new computational fluid dynamics simulation approach based on the constraint interpolation profile (CIP) method is applied to tackle the violent sloshing problem. The present study considers two-dimensional sloshing phenomena in a rectangular tank. By the proposed method, the sloshing problem is viewed as a multiphase problem that includes water and air flows. A stationary Cartesian grid is used and the free surface is solved by an interface capturing method. The CIP combined unified procedure (CCUP) scheme was adopted for the flow solver, and both the CIP scheme and the CIP conservative semi-Lagrangian with cubic interpolation polynomial (CIP-CSL3) scheme were used for interface capturing. For validation of the numerical method, a physical experiment was conducted with a rectangular tank for several frequencies and filling heights. A convergence check was first performed for the method. The numerical simulation results on violent sloshing show that the use of the CIP-CSL3 scheme as an interface capturing procedure gives much better results for the pressures and free-surface profiles than the conventional CIP scheme.     

简析试航燃油消耗率的计算和影响因素

分析影响商船试航期间主机燃油消耗率的因素,探讨在船舶空载和特定工况条件下,主机测量的燃油油耗率偏高的原因及改进方法。     

海事行政强制措施具体形态探讨

文中以《海事行政强制实施程序规定》的修订为背景,从海事行政强制措施的内涵和特征出发,探讨和归纳了海事行政强制措施的具体形态,对于正确理解与运用海事行政强制措施,提升依法行政能力具有重要意义。     

旅客列车纵向冲动问题研究

介绍了自铁路提速以来影响旅客列车纵向冲动的基本因素;从旅客列车编组辆数、速度以及基础制动形式、车钩类型、制动装置的制动波速、线路情况、司机操纵情况等方面,分项研究了对旅客列车纵向冲动的影响;并提出了改善提速旅客列车纵向冲动的措施。