循环移位扩频水声通信技术研究磁

直接序列扩频通信系统因为其优良的相关性能,能够在较低的信噪比条件下进行可靠地工作,而拥有良好的抗多径和抗干扰的能力。这对于水声通信信息的无误码传输都是极为可贵的。可是,常规的直接序列扩频水声通信系统的通信速率很低,针对这一特点,论文研究了循环移位扩频水声通信方式,它在保证一定抗干扰能力的前提下成倍数提高直接序列扩频通信系统的通信速率。     

基于广义GM（1,1）预测模型的装备管理费用预测

针对目前对武器装备寿命周期费用估算建模难以实施的情况,以准确预测武器装备寿命周期费用的主要组成部分——装备管理费用为出发点,依据装备管理费用的特点建立了装备管理费用的广义GM（1,1）预测模型,通过对某舰船系统装备管理费用的实例应用预测效果较好.     

粉土地区框架桥设计要点

框架桥作为道路下穿铁路的立交形式具有比较明显的优点,但在粉土地区易受到地下水的影响而产生问题.通过分析粉土地区框架桥在施工期间及运营期间由于地下水问题导致的常见病害,结合新建和改建项目不同的工程实例,提出了工程设计中在基坑支护、地下水降排、结构接缝处理、既有框架病害整治等可采取的相关描施及设计要点.     

Jointly optimizing cost, service, and environmental performance in demand-responsive transit scheduling

In certain fleet systems, the environmental impacts of operation are, to some extent, a controllable function of vehicle routing and scheduling decisions. However, little prior work has considered environmental impacts in fleet vehicle routing and scheduling optimization, in particular, where the impacts were assessed systematically utilizing life-cycle impact assessment methodologies such as those described by the Society of Environmental Chemistry and Toxicology. Here a methodology is presented for the joint optimization of cost, service, and life-cycle environmental consequences in vehicle routing and scheduling, which we develop for a demand-responsive (paratransit or dial-a-ride) transit system. We demonstrate through simulation that, as a result of our methodology, it is possible to reduce environmental impacts substantially, while increasing operating costs and service delays only slightly.     

恒磁场对人白血病细胞生物效应的研究

用流式细胞术探讨了恒磁场对人白血病细胞系HL－60细胞周期的影响，磁场与长春新碱的协同作用。结果表明：恒磁场可以引起HL－60细胞周期的改变，经700mT恒磁场作用后细胞的S％降低；而2260mT的磁场处理则使细胞的S％增加。上述场强的恒磁场均可增加HL-60细胞对长春新碱的敏感性。     

一种智能化实时监测系统的研究

作者从构造一个智能化实时监测系统的关键技术入手,对系统的设计与实现作了探索性的介绍。     

Optimisation of full-toroidal continuously variable transmission in conjunction with fixed ratio mechanism using particle swarm optimisation

The aim of this research is the optimisation of full-toroidal continuously variable transmission (CVT) in conjunction with the fixed ratio (FR) mechanism, while the optimisation objective is to minimise fuel consumption (FC) of the vehicle in the new European driving cycle. After the dynamic analysis of the power train, a computer model is developed to simulate contact between CVT elements and consequently calculate its efficiency. Then an algorithm is presented to calculate FC of the vehicle in the driving cycle. Then, an optimisation using particle swarm optimisation on the CVT geometry and FR mechanism (which is embedded between CVT and final drive) is carried out to minimise FC. It is found that by utilisation of the optimised CVT; FC will be about 11% and 8% lower, compared with the application of a five-speed manual transmission and conventional CVT, respectively. Finally, effects of the roller tilt angle and oil temperature on the FC are investigated.     

基于负荷平衡的流水线生产节拍设计

提出了在有排序约束和无排序约束两种情况下的流水线节拍设计方案,能有效解决流水线负荷平衡问题.该设计方案通过优化选取工作节点和工作节拍、有效组合任务元素、降低工作节点间等待时间等有效措施,来提高设备利用率、实现流水线负荷的平衡,进而达到提高流水线生产产量的目的.     

怠速转速对整车燃油经济性的影响

用理论与试验相结合的方法对整车降低怠速转速后的节油效果进行了研究,结果表明怠速转速降低50r/min,怠速油耗降低6%左右。在城市道路行驶怠速工况较多,降低怠速转速后整车节油效果较好,但是NEDC测试循环怠速工况时间短且怠速油耗量小,加之测试与设备误差等原因,很难直接测试出降低怠速的节油效果,为此提出了采用NEDC工况拆解法来计算降低怠速转速后的油耗与节油效果。     

基于道路载荷谱的柴油机激励分析和台架试验循环研究

基于车辆典型路面行驶产生的道路载荷谱,对发动机的典型运行工况和瞬态行为进行了分析和研究,构建了基于道路载荷的台架运行循环。研究表明:1 500r/min和1 600r/min是车辆行驶过程中柴油机的常用转速,其使用频率远高于其他转速;转速超过1 800r/min时柴油机多数工作于满负荷工况点;柴油机在1 400~1 800r/min运行时主要集中在中高负荷工况,负荷百分比统计值高于60%;整个载荷时间历程中,500~600r/min幅度的转速跃变比例高,且转速最大跃变不会超过1 000r/min。构建的台架运行循环与实际道路载荷强度相似、转速分布类似,能够表征车辆行驶过程中柴油机的激励状态。