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我国多数道路是典型的混合交通,交通组成复杂,相互间干扰现象严重. 含有小汽车、货车和其他车型的混合交通备受研究者的关注. 本文构建一个考虑道路收费的多用户网络均衡模型,在模型中,各类用户拥有各自的时间延误函数和道路收费,且相互影响不同. 折算系数（PCE）为可变的,构建的道路延误函数是非线性,非连续和非对称的. 混合交通网络均衡模型采用变分不等式构模,用相继平均（MSA）方法进行求解. 最后,在交通规划软件EMME/3中实现该算法并应用到实际公路交通网络,并对线性折算系数和非线性折算系数下的交通网络分配结果进行了对比. 研究表明,非线性折算系数更加符合实际区域网络交通流分布.     

基于菜籽油的汽油机油基础油

考虑到可生物降解润滑油在润滑性能和生物降解性能两方面的要求, 选用菜籽油作为基础油, 并合理选用添加剂, 按照均匀设计方法, 安排多因素试验, 考察了润滑油抗氧化性能, 提出了10W/40SG级汽油机油的优化配方。进行了该配方与国外成品汽油机油的使用性能和可生物降解性能的对比试验, 结果表明, 其质量水平已达到10W/40SG的性能要求, 且生物降解性能优于同类矿物基润滑油。     

Optimal competitive freight network design as hierarchical variational inequalities programming problems

Freight networks are a case of systems that multiple participants are composing interrelations along the complete supply chain. Their interrelations correspond to alternative behavior, namely, cooperation, non-cooperation and competition, while they are large-scale spatially distributed systems combining multiple means of transportation and the infrastructure and equipment typically utilized for servicing demand, results to a complex system integration. In this paper, the case of the optimal design of freight networks is investigated, aiming to highlight the particularities emerging in this case of transportation facilities strategic and/or operational planning and the multiple game-theoretic and equilibrium problems that are structured in cascade and in hierarchies. The application that is investigated here focuses in the design of a significant ‘player’ of the freight supply chain, namely container terminals, while the proposed framework will aim on analyzing investment strategies built on integrated demand–supply models and the optimal network design format. The approach will build on the multilevel Mathematical Programming with Equilibrium Constraints (MPECs) formulation, but is further extended to cope with the properties introduced by the ‘designers’ (infrastructure authorities), shippers and carriers competition in all levels of MPECs. Since container terminals are typically competing each other, the nomenclature used here for formulating appropriate MPECs problems are based on hierarchies of Variational Inequalities (VI) problems, able to capture the alternative relationships emerging in realistic freight supply chains. The proposed formulations of the competitive network design case is addressed by a novel approach of co-evolutionary agents, which can be regarded as new in equilibrium estimation. Finally, the results are compared with alternative network design cases, namely the centralized cooperative and exchanging design. Under this analysis it is able to highlight the differences among alternative design cases, but moreover an estimation of the ‘price of anarchy’ in transportation systems design is offered, an element of both theoretical as well as practical relevance.     

桥渡壅水计算

在总结桥梁壅水的研究成果的基础上,对我国公路设计规范(1992年版)计算桥梁壅水公式的改进形式与现行铁路设计规范公式做了对比分析,提出新的正交桥壅水计算公式,并采用正交桥天然资料进行了验证。     

箱梁剪滞效应的解法研究

用正弦函数代替挠度、余弦函数代替位移差值函数,考虑剪滞翘曲应力的轴向自平衡,应用变分法的最小势能原理,推导出具有一般箱型截面梁的剪滞效应三角级数计算式,将求解复杂的剪滞效应简化为求解一个二元一次方程式。以一简支箱梁为例,通过ANSYS数值模拟与所提计算式计算结果对比可知,所提计算式具有很高的精度,且算法简单快捷。     

一个三角形中线不等式猜想的证明

采用三角形不等式中R—r—s方法,证明了作者多年前提出的一个有关三角形的猜想不等式,即有关中线ma,mb,mc与外接圆半径R以及内切圆半径r的不等式：1Ama＋1／mb＋1／mc≤2（1／R＋1／r）／3．     

一个角平分线猜想不等式的证明

应用三角形一个重要的基本不等式,证明了有关三角形内角平分线之和的一个猜想不等式:设wa,wb,wc与s分别是三角形三条内角平分线和半周长,R,r分别为三角形的外接圆半径,则(wa wb wc)2s2 102Rr/5 66r2/5.指出了一个相关的值得进一步探讨的问题.     

Wave Number Method for Three-Dimensional Steady-State Acoustic Problems

Based on the indirect Trefftz approach, a wave number method (WNM) is proposed to deal with three-dimensional steady-state acoustic problems. In the WNM, the dynamic pressure response variable is approximated by a set of wave functions, which exactly satisfy the Helmholtz equation. The set of wave functions comprise the exact solutions of the homogeneous part of the governing equations and some particular solution functions. The unknown coefficients of the wave functions can be obtained by enforcing the pressure approximation to satisfy the boundary conditions. Compared with the boundary element method (BEM), the WNM have a smaller system matrix, and is applicable to the radiation problems since the wave functions are independent of the domain size. A 3D acoustic cavity is exemplified to show the properties of the method. The results show that the wave number method is more efficient than the BEM, and it is fairly accurate.     

等截面薄壁梯形箱梁剪力滞效应分析

假定箱梁的纵向位移沿横截面满足余弦函数分布,考虑荷载沿横向的作用位置的影响,采用广义变分原理推导出了等截面梯形箱梁发生对称挠曲时的剪力滞效应表达式,并与三次抛物线法的计算结果进行对比,证明了计算假定的合理性.     

非匹配不确定奇异系统变结构控制设计

研究一类系统状态矩阵含非匹配不确定项的线性奇异系统的变结构控制设计问题.建立了能控规范受限等价分解形式.基于分解形式,利用线性矩阵不等式方法设计了切换面,并给出了满足系统状态到达切换面条件的变结构控制律.仿真示例表明,该设计方法不仅能保证系统状态轨迹实现滑模运动,而且保证系统的滑模运动正则、无脉冲且渐近稳定.