轻型客车偏置碰撞安全性改进设计的台车方法

为了提高某轻型客车的偏置碰撞安全性,在外形保持不变以尽可能节约成本的前提下对车身进行改进。根据轻型客车大多采用半承载式车身,车架是主要的吸能部件的特点,把车架作为重点改进对象,采用台车试验和台车模拟相结合的方法,提高其正面偏置碰撞安全性能。     

EPS用永磁同步电机的2自由度内模控制研究

针对电动助力转向用永磁同步电机采用了一种2自由度内模转矩控制方法,通过调整控制参数,可分别设定系统的跟随性和对干扰及噪声的抑制特性,仿真得出的电机控制效果在台架实验中得到了验证。     

基于进化算法的冲压模具型面参数优化

提出了基于计算机结构优化设计的进化算法(EA).算法结合逆向有限元模拟实施,以厚向应变分布均匀为目标函数,在搜索空间内寻找全局最优化的区域.通过对某汽车零件拉延成形的分析证明,该算法具有很高的可靠性和稳健性,对实际工程中冲压模具的设计具有指导意义.     

胆汁致胃黏膜损伤中瘦素、环氧合酶-2及p27的表达

目的通过大鼠实验模型观察瘦素(leptin)、环氧合酶-2(COX-2)及p27在胆汁所致胃黏膜损伤中的作用。方法SD大鼠分成4组:十二指肠胃反流(duodenogastric reflux,DGR)组、DGR 胆管结扎(bile duct ligation,BDL)组、胆管结扎组(BDL)、假手术组(control,C)组。术后12周处死大鼠,观察胃黏膜损害及病理组织学改变,计算DIX-ON积分;免疫组化(SP)法检测各组大鼠胃黏膜瘦素、COX-2及p27表达。结果DIXON积分DGR组、DGR BDL组较BDL组及假手术组积分均升高(P<0.05),DGR组较DGR BDL组DIXON积分升高(P<0.05);DGR组、DGR BDL组与BDL组及假手术组比较大鼠胃黏膜瘦素、COX-2高表达(P<0.05),p27低表达(P<0.05),DGR组比DGR BDL组高表达尤为明显(P<0.05)。DIXON积分与瘦素、COX-2表达呈正相关,与p27表达呈负相关。结论胆汁反流致胃黏膜损伤过程中,瘦素、COX-2及p27蛋白与病变的修复过程有关。     

一种改进的求解QoS多播路由问题的蚂蚁算法(英文)

为了克服基本蚂蚁算法收敛速度慢、容易早熟和陷入局部最优解的缺陷,提出了一种求解QoS多播路由问题的改进型蚂蚁算法.该算法采用相遇蚂蚁策略来加快搜索速度,采用最优解更新和信息素自适应控制策略来避免出现停滞现象.仿真结果验证了该算法的可行性和有效性.     

Role of the built environment on mode choice decisions: additional evidence on the impact of density

Density is a key component in the recent surge of mixed-use neighborhood developments. Empirical research has shown an inconsistent picture on the impact of density. In particular, it is unclear whether it is the density or the variables that go long with density that affect people’s travel behavior. Many existing studies on density neglect confounding factors, for example, residential self-selection, generalized travel cost, accessibility, and access to transit stations. In addition, most still use a single trip as their observation unit, even though trip chaining is well recognized. The goal of this paper is to assess the role of density in affecting mode choice decisions in home-based work tours, while controlling for confounding factors. Using the dataset collected in the New York Metropolitan Region, we estimated a simultaneous two-equation system comprising two mutually interacting dependent variables: car ownership and the propensity to use auto. The results confirm the role of density after controlling for the confounding factors; in particular, employment density at work exerts more influence than residential density at home. The study also demonstrates the importance of using tour as the analysis unit in mode choice decisions. The study advances the field by analyzing the role of the built environment on home-based work tours. New knowledge is obtained in the relative contribution of density vs. a set of correlated factors, including generalized travel cost, accessibility, and access to transit stations.

采样方式对柴油机微粒排放测量的影响分析

采用国Ⅲ标准ESC测试流程,在AVL AFA490试验台上对同一柴油机同步采用两种采样方式进行了颗粒物对比测量.测量结果表明,全流稀释颗粒采样系统的微粒排放量测量精度和准确度高于采用分流稀释颗粒采样系统的测量结果.经分析指出,采用分流稀释颗粒采样系统进行微粒测量时,应严格控制稀释空气质量以及探头的安装位置和伸入排气管中的长度.     

轨道交通结构化布线系统的设计

城市轨道交通布线系统不仅要考虑系统的拓扑结构、传输性能,还要考虑消防、管理、系统升级等方面的要求.布线系统的设计,应重点考虑安全性、可靠性和电磁兼容三个方面:采用低烟无卤电缆,可满足防火性能的需求;采用DataGate内置防尘门技术和KATT卡线技术,提高了铜缆数据传输系统的可靠性;采用光纤链路,并且通过调整拓扑结构的配置,改善了电磁兼容性能,实现高可靠性数据传输的需要.     

浅谈航海训练模拟器教学

简要介绍航海训练模拟器教学的设置和安排。     

STUDIES ON THE RELATIONSHIP BETWEEN SUBSTANCE P AND ABNORMAL GASTROINTESTIANL TRANSIT

Substance P is a peptide which is composed of1 1 kinds of amino acid.This peptide is one of themembers of the tachykinin s family.It can be re-leased by intrinsic neurons of gastrointestine andexternal nerve,forexample,Vagus nerve.Some ofthese neurons are situated in nerve plexus which islocated under gastrointestinal mucosa and othersare situated in nerve plexus between longitudinalmuscle and circular muscle.SP can make gastroin-testinal smooth muscle contract and promote themovement of gas…