周期函数的几个判定定理

周期函数是数学中比较重要的概念之一,本文给出了几个周期函数的定理并加以证明.     

Flight delays,capacity investment and social welfare under air transport supply-demand equilibrium

This paper analyzes benefits from aviation infrastructure investment under competitive supply-demand equilibrium. The analysis recognizes that, in the air transportation system where economies of density is an inherent characteristic, capacity change would trigger a complicated set of adjustment of and interplay among passenger demand, air fare, flight frequency, aircraft size, and flight delays, leading to an equilibrium shift. An analytical model that incorporates these elements is developed. The results from comparative static analysis show that capacity constraint suppresses demand, reduces flight frequency, and increases passenger generalized cost. Our numerical analysis further reveals that, by switching to larger aircraft size, airlines manage to offset part of the delay effect on unit operating cost, and charge passengers lower fare. With higher capacity, airlines tend to raise both fare and frequency while decreasing aircraft size. More demand emerges in the market, with reduced generalized cost for each traveler. The marginal benefit brought by capacity expansion diminishes as the capacity-demand imbalance becomes less severe. Existing passengers in the market receive most of the benefit, followed by airlines. The welfare gains from induced demand are much smaller. The equilibrium approach yields more plausible investment benefit estimates than does the conventional method. In particular, when forecasting future demand the equilibrium approach is capable of preventing the occurrence of excessive high delays.     

基于模糊控制策略的PHEV仿真研究

针对并联式混合动力汽车,在电辅控制策略的基础上设计一种基于模糊逻辑推理的动力分配控制策略。将其模型嵌入仿真软件ADVISOR中,在CYC_EUDC循环道路工况下进行仿真计算。仿真结果表明:与电辅控制策略相比,采用模糊逻辑控制策略的混合动力电动汽车具有较好的经济性、排放性、鲁棒性,能够使发动机尽量集中工作在优化工作曲线附近,并保证电池SOC在较小的范围内变化。     

煤矿斜井TBM施工长距离反坡排水技术

结合TBM法施工煤矿长距离斜井面临埋深达660m、反坡坡度为6°（-10．5％）、地层富水的问题,通过斜井排水管线路设计、排水设备及储水水仓等设计研究,从经济可靠的角度出发,提出TBM斜井分级、分流量梯度反坡排水方案,解决TBM长距离反坡排水施工技术难题。     

ADS8361在DSP数据采集系统中的应用

介绍了ADS8361的基本原理和工作方式,以其在数据采集系统中的应用为例,给出了在矢量水听器信号采集中的具体应用方法,对AD器件的选择、接口及软件设计、具体实现方式,及电路调试进行了详细分析。外场试验表明,该采集系统稳定可靠。     

在城市立交工程设计中引入“人因工程学”理念

该文介绍了"人因工程学"的内涵,阐述了将"人因工程学"引入城市立交工程设计的意义,并通过对驾驶员行驶立交时的心理特征分析,论述了引入"人因工程学"理念,对构建人、车、立交相协调、和谐的交通环境的必要性。     

径向转向架的发展及其动力学分析

介绍了径向转向架的结构、导向原理和特点，探讨了迫导向径向转向架各部件对转向架性能的影响。     

水面舰艇规避自导鱼雷的建模计算与分析

通过对水面舰艇规避来袭自导鱼雷过程的分析,建立了水面舰艇规避鱼雷的战术基础模型,对水面舰艇规避来袭自导鱼雷效果进行了建模计算,给出了水面舰艇防御鱼雷的组织方法,对研究水面舰艇规避鱼雷战术具有一定的参考价值.     

秦皇岛港煤五期翻车机房及廊道地连墙侧向变形监测分析

秦皇岛港煤五期翻车机房及廊道工程基础采用地下连续墙形式。由于地下连续墙施工难度大、施工工期要求高,为了保证该工程顺利完成,同时为类似工程积累数据,在施工过程中对工程的变形、应力及压力等方面进行了详实的观测。通过对侧向变形实测结果分析,指导了工程施工。     

谈如何运用好公路施工监理的几个工作手段

公路施工监理能否运用好监理工作指令、工地会议、工程抽检转序和监理日志记录等四个最重要的监理工作方法是体现监理工作质量的关键。